DE2633880A1 - METHOD AND DEVICE FOR QUICK TESTING OF ENGINE EXHAUST GAS - Google Patents

Description

EISEN FÜ HR & SPEISER sponsors τ lawyers

D.r ^ -lNG. 3UNTHiR eiFFnfHR DlPL.-lNG. DIETER K. SPEISER BREMEN Dr.rer NAT.HORST ZINNGREBE

US. CHARACTER: C 67

Applicant / iNH: Clayton Manufacturing Company File number: Neuaniiildung

Date: June 30, 1976

CLAYTON MANUFACTURING COMPANY, incorporated under the laws of the State of California, 4213 Temple City Boulevard, El Monte , California, V. St. A.

Method and device for rapid testing of engine exhaust gases

The invention is concerned with a method and a device for quickly and accurately checking the portion of the main air pollutants in exhaust gas from internal combustion engines. She also deals with the diagnosis of engine malfunctions that are related to the exhaust gas as well with the establishment of instructions on how to remedy the faults.

As is well known, the engine exhaust gases of vehicles represent a major source of air pollution. Therefore, the special effort is directed to gain standards for permissible levels of emissions from CO, hydrocarbons, NO and O ₂ and to create methods and devices for testing emissions to be able to determine as quickly as possible whether the permissible values have not been exceeded.

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2G33880

As part of this effort, the authorities (particularly in the United States of America) have announced that that regular tests to determine the presence of pollutants in the engine exhaust must be carried out. Such Tests capture the typical driving in city traffic by average drivers and are for the approval of newers Engines or engines in new vehicles are satisfactory. However, such tests are very time consuming and too complicated for large-scale vehicle inspection. In addition, they do not allow data to be obtained, from which the cause of the engine failure can easily be determined. With the masses to be expected for the future Vehicle inspection and a large number of rejections are the existing repair shops hardly finish and show yourself to be able to cope with the situation that then arises. What is actually needed In order to be able to carry out the necessary repairs on an engine that has been found defective, is a quick one Method and the simplest possible device for determining the pollutants in the engine exhaust gases in order to thereby to gain a reliable diagnosis of the existing engine damage, which is responsible for the excessive production of pollutants responsible for; Furthermore, a manual for the workshop repairman is needed, which enables him to fix the damage very quickly with a correct adjustment or repair.

Another disadvantage of the official test cycles is that they are suitable for use as monitoring of the Fahrjäug-related Air pollution at the inspection bodies of the municipalities, districts and federal agencies are impractical. The main disadvantage here too is that these tests take too long. Another disadvantage is that they only

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are difficult to execute. After this has been carried out, no information is available that could Diagnosis of the damage would allow and which would allow the workshop mechanic to have direct access fix the damage.

None of the other short tests or rapid tests have proven to be satisfactory because, on the one hand, they are considerable Need skill to perform, are unrepeatable, and ultimately unnecessary setup and require operating costs and, finally, they are not capable of weeding out vehicles that are during unload abnormally high pollutants while driving. It is also not yet possible to remove the gaseous pollutants in the exhaust gas in a manner that will allow an accurate diagnosis of the particular fault that is responsible for the occurrence of the is the cause of excessive amounts of pollutants. Furthermore, that is missing Workshop fitters provide the necessary support and instructions for repairs, which usually do not have their own dynamometer or has other appropriate equipment to remedy defects or damage to the exhaust gas Diagnose machine.

The difficulties mentioned occur with the invention ~ according to the procedure for testing engine exhaust emissions, which prescribes and a test procedure for this purpose developed system, which requires only one minute per vehicle to run and with an extremely simple device works. The prescribed test system is particularly on the en masse Vehicle inspection tailored to identify excess pollutants in emissions and provides a diagnosis that reveals the cause. The method according to the invention also includes the establishment of report cards that indicate the amount of CO and HC pollutants in the exhaust gases, whereby this report card

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handed over to the vehicle owner during the inspection so that e: c drive this and the vehicle to the workshop and have the fault or damage repaired can. The prescribed procedure also includes the preparation of analysis diagrams showing the causes of the Suspect errors and provide instructions for remedial action and elimination for the workshop mechanic.

As a result of testing the exhaust emissions of a large number of vehicles from the cross section of the whole Vehicle inventory and the repairs carried out on these vehicles has after careful study and a precise analysis of the test data show that a very satisfactory determination of the exhaust gas emissions of CO and HC can be carried out by testing the motors under certain operating conditions, under which the engine damage is likely to occur; the resulting values can be used to practically very precisely indicate the engine damage that is related to the pollutant emission.

According to the invention, three prescribed test methods are established for three different vehicle weight classes are provided after the official emissions tests classify the vehicles according to their weight. Of course you can more or less than three weight classes or parameters are used, such as the displacement, the number of cylinders, etc., these values of course either individually or in combination with one another for classification of the vehicles can be used. These three tests are equally applicable to all weights or types of vehicles equipped with internal combustion engines can be used, with suitable variations in terms of the

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taken load (power) can be made to compensate for the classification. Accordingly, Mode 1 requires the engine to be operated under a load (power) simulating high cruising speed, with the engine's carburetor and ignition system in full operation. Mode 2 requires the engine to be operated at low cruising speed, which means that the test is carried out in the transition region between engine idling and the engine speed at which the carburetor or carburetors and the ignition are fully operational. Mode 3 mandates testing at idle when the engine is operating with the carburetor door normally closed, that is, without the driver putting any pressure on the door. The idling test according to the third mode is carried out because this test should be made at a time when the intake system has been cleaned of residual fuel and the engine parts have assumed a constant temperature. The amounts of CO and HC (the letters HC stand for the abbreviation: hydrocarbon) are measured and the specified, acceptable amounts are compared in all test modes. The values of NO and O ₀ can also be measured and compared to acceptable values using one or more of the above-mentioned or other test modes.

In contrast to the relatively slow state test cycles the method according to the invention, according to which emission tests can be carried out in three selected modes, be completed in a minute or less. Other modes such as full flap and / or those that allow for expansion are required in a detailed diagnosis or to check the actual function of the tuning or temporary vehicle controls used to monitor gases such as NO require additional

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Time. This will set the procedure for the mass implementation of emissions tests on urban, state-owned and federal inspection stations extremely practical and for use in vehicle diagnostic centers extremely desirable, in which further tests on the measurement of exhaust gas emissions are carried out, because minimized the time required to perform exhaust emission tests according to the prescribed test mode will. Depending on your choice and sometimes on the basis of expediency, a fourth mode will be useful, with the one fully open Carburetor flap is tested, namely when all systems of the engine are under the greatest or almost the greatest load work.

The mode test system according to the invention for measuring exhaust gas emissions can be applied to engines, they are new or old and irrespective of whether they are in a vehicle are built in or not. A mode system is used only for the purpose of explaining the invention in more detail in connection with the use of a chassis dynamometer, which is a very simple option opened for testing engines during its installation in the vehicle at simulated vehicle speeds. this is also the most widespread use for implementing the mode method according to the invention. An engine dynamometer or chassis dynamometer can also be used if the degree of power absorption (on load) is chosen can be adapted to the prescribed performance requirements at prescribed speeds. In the event that a prescribed emission test requires acceleration and / or deceleration, a dynamometer must be used can be used that can absorb the vehicle power normally required to overcome the Wind resistance and the inertia of the vehicle mass

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the road is consumed. This can easily be achieved by doing this that a device with variable torque / power absorption and flywheels can be used.

The module test system according to the invention can also indicate whether the NO control units are working on the engine.

A display device with special markings for the loads "high cruising speed" and "low cruising speed" for the various vehicle weight classes form instructions for operation, so that the vehicle throttle can be correctly positioned so that the load as prescribed for mode 1 (high Cruising speed), mode 2 (low cruising speed) and mode 3 (idling) can be adopted. The operation monitors and records the CO and HC values on the report card for each operating mode.

It is therefore an essential object of the invention to provide a reliable, accurate and rapid method and a to create extremely simple device for testing old and new engines as well as engines installed in vehicles, with it it can be determined whether these motors are unacceptably high pollutants.

Another concern of the invention is to provide a rapid method for testing exhaust emissions, This is a rejection or approval of an engine after comparison with specified permissible values for CO, HC, NO. and / or 0 ~ exhaust emissions allowed.

Furthermore, a simple device for testing an engine is to be created, in which the engine with a number of Loads are applied at predetermined speeds,

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where the issues related to the issue are most likely to occur. In doing so, the engine is supposed to be tested that it is subjected to a series of predetermined speeds and loads, which are at for a given speed / power are essentially on a cubic curve. Another essential one The concern is that the process to be created and the associated device should be used on a large scale Testing of vehicles for exhaust emissions at municipal, state or federal inspection stations or Automatic diagnostic centers should be usable to ensure compliance with the prescribed permissible levels of air pollutants to be determined in the exhaust gas emission.

Furthermore, the process to be created and the associated function should allow a module test cycle to be repeated by Ensure test person to test person and system to system in which large numbers of vehicles daily check for compliance the air pollution regulations are checked.

Finally, the method according to the invention and the associated device should deliver reliable test results of the exhaust gas emissions and reduce the time required for this considerably and thus also lower the costs to be incurred for an inspection. The method according to the invention and the associated device are intended to determine the amounts of CO, HC, NO and O ₀ in the exhaust gases very precisely and to estimate the operating state of the engine. Finally, the device according to the invention should be able to be carried out by untrained and inexperienced persons. The method according to the invention and the associated device are intended to considerably simplify the inspection of vehicles and support the repair of defective engines by giving a mechanic a

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Report card is made which is the basis of the rejection contains forming values of CO and / or HC; Furthermore, an analysis diagram should be set up in which ' A number of damages and the suspected causes as well as their remedies are given so that the elimination of the indicated damage can happen relatively easily. Another concern of the invention is the repair mechanic to provide diagnostic data about a defective engine that has been caused by excessive Emissions of CO and HC has been shown, with the mechanic also providing simple instructions for the execution of adjustments or repairs to rectify the damage. With the method according to the invention at Testing an engine in a vehicle subjected to the latter predetermined loads, taking into account the Vehicle class a high cruising speed, a low cruising speed and idling and possibly one drawn starter, with the values of CO and HC contained in the exhaust gas in each mode being measured should. The method according to the invention is also intended to provide a Engine can be tested, which is equipped with a device for reducing the NO content, the content measured at NO in the exhaust gas and indicated whether the additional device is still working properly to reduce the NO content.

The invention is described in detail in the following, reference being made to the accompanying drawings.

Show in detail:

1 shows a schematic perspective illustration of a chassis dynymometer with a power absorption unit (Brake unit), which means for performing the individual modes of the invention Method for determining engine exhaust loads can be used;

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Fig. 2 an explanation of the relationship between power / speed, the approximated cubic curve the power absorption of the device of Fig. 1, from which the speed and power to the Mode points 1, 2 and 3 can be read;

3 is a schematic diagram of the components of an exhaust gas analyzer with which exhaust gas emissions can be determined and which contains measuring devices for measuring the values of CO, HC and NO and, if desired, a printer; ^x

4 shows an enlarged illustration of a scale for the load index, shown as a speedometer, which gives the worker a guide for achieving predetermined loads with the individual mode points there;

FIGS. 5 to 7 are views of the scales for the measuring devices for the values of CO, HC and NO;

8 shows a representation of a report card with the occurrence of permissible CO and HC values, and the entries justifying the rejection in the HC columns for all operating modes;

9 shows a representation of a report card similar to that of FIG Values for NO can be entered;

FIG. 10 shows a report card similar to that of FIG. 8 additional columns for recording the emission values when operating with fully pulled starter flap;

Fig. 11 another report card with entry options for fully extended choke and NO values;

Fig. 12 an example of a diagnosis card with an entry the reasons for rejection according to the report card from FIG. 8;

13 shows a perspective illustration of a further embodiment a chassis dynamometer with which the individual operating modes of the engine test are carried out can be, with additional facilities to simulate the inertia of the vehicle masses are provided for acceleration and deceleration;

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Fig. 14 is a block diagram of an automatic control system according to the invention;

15 shows a schematic diagram of the assemblies of an exhaust gas analyzer for measuring the content of CO, HC, NO _v and O ₀ ;

16 is a block diagram of an analog-to-digital converter in which the analog signals from the gas analyzer be set into digital signals;

Figure 17 is a view of the control panel and dynamometer display panel as part of the tax system;

18 shows a further embodiment of the measuring device for Display of the load, instructions and help for the operator in operating the device gives;

19 is a view of a portable operator control unit which can then be actuated when he is sitting in the vehicle;

Fig. 20 is a block diagram of the various storage elements; in which the acceptable values of the individual gases can be stored;

Fig. 21 is a block diagram of a comparison circuit for comparing the measured values with the acceptable ones Values;

22 shows a block diagram of a circuit for testing the operating behavior of a TSAD-NO control unit;

23 shows a block diagram of a circuit for testing the operating behavior of a SAD-NO control device;

23A is a schematic diagram of a vacuum sensor to test the engine vacuum controls that work together with the NO control units;

Fig. 24 is a block diagram of a circuit for checking the operating behavior of an EGR-NO control device;

Fig. 25 is a block diagram of a circuit for checking the Operating behavior of an SSAD-NO control unit;

26 is a block diagram of a circuit for evaluating the O2 quantities in the exhaust gas when the engine or the Vehicle is not equipped with exhaust gas afterburning or a catalytic converter;

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27 shows a block diagram of a circuit for evaluation the amount of O in the exhaust gas if the engine or vehicle is equipped with a catalytic converter is not equipped, but is equipped with an exhaust gas afterburner;

Fig. 27A is a block diagram showing the remaining circuit parts of Fig. 27;

Fig. 28 is a block diagram of a circuit for testing

the effectiveness of a catalytic converter;

Fig. 29 is a view of a result display panel for the automatic control system;

Fig. 30 is a block diagram of a circuit including a printed engine failure indicator and a Issues instructions for setting and repairing excessive CO and HC content;

31 is a schematic diagram of a portion of a stabilizing circuit for the loading and unloading Gas signal which can be used within the circuit of FIG. 21;

Fig. 32 is a schematic diagram of the remaining part of the stabilizing circuit of Fig. 31;

and

Fig. 33 is a graphic diagram for explaining the performance of the stabilizing circuits from Figs. 31 and 32.

14ANUAL TESTING SYSTEM

The chassis dynamometer 2 shown in Fig. 1 has a hydraulic power absorption device (braking device) 4, with which the vehicle engine, not shown, can be loaded. An inlet 6 allows the introduction of water into the Working circuit of the absorption device 4, which can leave the device from an outlet 8, so that during execution During the tests, a continuous stream of water flows through the absorption device. The usual brake air holes, not shown They remain open, so that air pockets form in the water ice

can not train and it remains assured that the engine under test is maintained at constant speed / power ratio.

A drive roller 10 is connected directly to the shaft 11 of the absorption device 4 and parallel to a freely rotating roller 12 arranged. The wheels 14 (only one of which is shown) of the vehicle rest between the drive roller 10 and the driven roller 12. A speedometer generator 16 is used driven by a belt 18 from the driven roller 12 and connected to a speedometer 20 which displays to the operator the simulated road speed of the vehicle taken by the vehicle wheels 14. That Absorption device 4 automatically loads the engine, so that a predetermined engine speed corresponds to a certain load.

The speedometer 20 with its scale is shown in more detail in FIG. This scale 22 has graduation marks 24 calibrated according to the road speed of the vehicle 14 and a pointer 26 is deflected by the current coming from the tachometer generator 16 and shows the current with the rollers 12 generated speed. The scale 22 has two red colored fields 28 and 30, which are a weight class for large vehicles weighing over 1.7 tenths. Field 28 is recorded the speed range from 48 to 50 miles per hour and corresponds to a fast cruising speed (mode 1) for Testing of vehicles in this weight class; the field 30 covers a speed range of 32 to 35 miles per Hour and corresponds to the slow cruising speed (mode 2) for vehicles of this weight class.

The yellow fields 32 and 34 on the scale 22 correspond to a second weight class for vehicles with one weight between 1.3 t and 1.7 t. Field 32 covers a speed range from 44 to 46 miles per hour and corresponds to

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a high cruising speed, and field 34 belongs to the speed range of 29 to 32 miles per hour and corresponds to the slow travel speed for vehicles of this weight class.

The black-speckled fields 36 and 38 on the scale 22 correspond to vehicles in a third weight class, namely from 0.9 to 1.3 t. The field 36 belongs to a speed range of 36 to 38 miles per hour corresponding to a high one Cruising speed and field 38 corresponds to a speed of 22 to 26 miles per hour corresponding to a low one Cruising speed for vehicles in this weight class.

Fig. 5 shows the scale of a meter 40 for carbon monoxide (CO). The scale 41 is divided from 0 to 10, so that the Pointer 42 can show the percentage of CO in the exhaust gas.

6 shows the scale 48 of a measuring device 46 for the content of hydrocarbons (HC), which is divided from 0 to 15 and shows the proportions of hydrocarbons in parts per million χ 100 in the exhaust gas.

Fig. 7 shows the scale 54 of a measuring device 52 for the oxides of nitrogen (NO), which is divided from 0 to 50 and can display the parts of NO per million χ 100 in the exhaust gas on the display 56.

The CO meter 40, the HC meter 46 and the NO meter 52 are the parts of an exhaust gas analyzer, its components schematically 3 shows. The analyzer includes a sample tube 58 that is inserted into the exhaust pipe 60 of the vehicle. The dem The gas sample supplied to the conditioner 62 is conditioned there and freed of entrained solids and liquids, after which a pump 64 continuously circulates the gas through the conditioning

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rer draws and a CO analyzer 66, an HC analyzer 68 and, if desired, to an NO 2 analyzer 70.

An electronic printer 72 of conventional design is connected to the named analyzers and automatically records the determined values of CO, HC and No from the measuring devices 40, 46 and 52 after they have reached their final value. To ensure that the tester has the prescribed module loads Has applied long enough so that the final values in the CO-HC- is a common electronic delay circuit 74 connected between the CO measuring device and the printer 72. Similar delay devices 75 and 77 can be connected between the HC measuring device 46 and the NO measuring device 52 on the one hand and the printer 72 on the other hand.

Fig. Figure 2 shows a power / speed curve for the absorption device 4 and is ideal for performing the mode tests of the invention. As stated, is the speed in miles per hour on the abscissa and road performance on the ordinate abaetraaen.

This essentially cubic power / speed curve runs through a point at the coordinates 30 hp and 50 mph. The absorption properties of some variable control dynamometers automatically or automatically follow a curve in which the Power changes essentially to the power of the third power of speed if a fixed absorption is chosen has been. Then the degree of absorption can be adjusted so that 30 horsepower is absorbed at 50 mph. If the controls are set so that this X index point is a Base load is obtained, then they follow the curve according to FIG. 2 very closely, even at other speeds ο 30 hp at 50 Miles per hour is great for testing large vehicles in the weight class over 1.9 t suitable for high travel speeds »For compact vehicles in the weight class from 1.4 t to 1.9 t results in an equal curve dadurhcj that the dynamometer

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is set to 24 horsepower at 46 mph, a value required for testing these vehicles in high cruising mode suitable is. For the lightweight vehicles imported to the USA that are in the From 0.9 t to 1.4 t, a setting of 15 hp is at 38 miles per hour suitable for testing the vehicles in high speed mode. Remember the tests for high cruising speed correspond to mode 1 according to the invention. The values for the loads and speeds for testing in mode 2 (low cruising speed) and mode 3 (idle) automatically follow the same curve as will be made clear from the following.

The mode selected is related to the different ones Phases of operation of the engine. For example, one mode relates to idling in which the entire engine is under stagnation The operating conditions specified by the vehicle manufacturer are running. With an engine idling, the ignition times are the ignition pauses, the engine speed and the idle carburetor setting with air / fuel ratio from the vehicle manufacturer prescribed and adjustable. The compression pressures and combustion temperatures are low and standing idle in fixed relation to the settings of the time, speed, temperature and the air / fuel mixture.

At higher than idle speed at which the engine is performing Developed to move loads, the above conditions change starting with the exception of the ignition pauses of the parameters that apply to idling. When the carburetor nozzle is opened, the power output of the engine and / or As you increase its speed, the airflow through the motor will continue to increase. The by the increasing air flow and / or engine speed generated signals generate an automatic control of the ignition point and the increased fuel supply. When the engine is idling, the fuel comes from the idling system of the carburetor. When the engine develops power the carburetor nozzle is opened and the required additional

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Borrowed fuel is from a main stream of the carburetor supplied, which is separated from the no-load current. Higher compression pressures, engine combustion temperatures, Fuel consumption and power consumption for the ignition system occur as a result of the increased nozzle opening on, with an increased air flow. Obviously, the engines can be successful work in one operating phase but not in another. From a practical standpoint, the procedures need to be be short for testing large numbers of vehicles so that testing and observing engine behavior except for those cases that may be symptomatic and within the power / speed capacity lie. The selected operating mode according to the invention is an equilibrium operating state more constant Engine speed and load. The modes are selected permanent state modes of the engine operation within of the power ranges and speed ranges of interest that are most reliable in the engine systems in one Manner that - if at all, then with probability - will lead to failure of the individual assemblies of the Systems can lead.

The number of modes used depends on the purpose of the test. The mutual legislation of Monitoring of vehicle emissions in the development of vehicles does not include the maximum speed and Power of most engines. Therefore, the mode test does not need the engine power and to monitor the emission - to exceed the speed required to issue the official emission certificate for the respective Year of the vehicles. An operational test of the engine is therefore used to test the upper areas of the Speed and power output. If more emission controls are added to the engines, this can be additional test-709807/0301

require points to check the function of the controls, in particular those that respond to changes address the vehicle speed and / or power output. The currently existing NO controls, that are used in older vehicles are individual cases that will be returned to below.

The mode method according to the invention for testing the motors works with a dynamometer or another suitable one power-consuming device, the predetermined loads at predetermined speeds in adaptation to the different vehicle classes, the speed and the load accordingly a fixed speed / load curve (Fig. 2), according to which the consumed power increases essentially changed with the cube of the speed, with mode deviations without, of course, Impairment of the results are permitted.

Depending on the type of variable, power-consuming dynamometer, a different power / speed characteristic can be obtained for a given load index. For example, the hydrokinetic energy consumers, which use a working medium as a liquid and, for example, in US Patents 2,452,550, 2 768 711 or 2 870 875 are described, or hydrokinetic power consumers who use a gas as the working medium work, have a cubic power / speed curve by themselves. These machines can on any point of the power / speed curve according to FIG. 2 can be set manually and also at the correct load is then applied at other speeds. The mentioned hydrokinetic machines work

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work with a liquid as the working medium and keep the entered or set load and therefore allow very good reproducibility. Adjusting these hydrokinetic energy consumers to a desired curve can also be carried out automatically with a device which, for example, is shown in U.S. Patent 3,818,754.

On the other hand, electrical or mechanical friction consumers do not obey the preferred cubic ones by themselves Power / speed curve and therefore require manual Setting at any speed and power or torque for each test point of the mode. Alternatively These consumers must be equipped with automatic controls that force them to create a repeatable power / speed curve to follow after the curve has been set once (or an appropriate index point has been entered).

Another alternative is so-called constant speed controls to use which seek to automatically maintain a preselected speed, regardless of the power input. In the latter case, each speed point of the test must be chosen and the nozzle can be manipulated until the desired absorbed torque, force or power is dissipated are achieved.

When the dynamometer is along a known power / speed curve works, needs the lead instrument for the operator, such as the tachometer or speedometer according to FIG. 4 and the performance index measuring device according to FIG Fig. 18 (which will be returned to below)

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only respond to one of the following parameters: power, speed or function of the torque.

It has been found that the implementation of the invention, modular test of the emission required loads (combination of speed and torque or speed and power) can be obtained from a single power / speed curve. The amount of power dissipation at a prescribed speed for the selected mode checks all common vehicles equipped with spark ignition and internal combustion engines as well as light trucks based on the same curve, for example that of Fig. 2.

The simple power / speed load mentioned above is particularly favorable for the purposes of the invention, since it allows the use of Lexstungsverzehrungsgeräte allowed to work according to a single power / speed curve. These machines are usually cheaper than those where the load can be varied manually, moreover, they require less skill and none Valuable operating time to make the necessary settings and then to carry out a test at the preselected load. The devices mentioned are therefore ideal for workshop testing of emissions. By pressing the conduction consumer with a fixed filling, i.e. with Working circuit completely filled with water within the device, with the water filling or the filling with another working medium over the whole time remains the desired power / speed curve assumed for the present mode by itself.

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This consumption characteristic cannot be changed by an operator error, nor can it automatic controls show malfunction. In addition, the power consumption device is not subject to an unnecessary one and excessive heating, because the device is continuously traversed by the working medium. By The use of power consumers with solid filling is not necessary Loading and unloading valves, torque arms, torque or force-developing instruments, etc., so that also through this the costs of the method according to the invention can be reduced considerably. When the power / speed curve should be changed, the power dissipation device can very easily be modified to be the new one desired Curve is adapted by replacing the rotor with another, which then meets the requirements of the modified approximately · cubic curve is fulfilled. Of course, other mechanisms than the power absorber devices can of course also be used with solid filling can be used for carrying out the tests according to the invention.

The execution of tests with the modes according to the invention is significantly simplified by the fact that a dynamometer is used that destroys the desired load by itself, at the selected speed, without the need for automatic controls or operator assistance. This can do that The method according to the invention can be carried out by an unskilled force, because the force only applies to the accelerator pedal need to press to open the carburetor jet the required amount and cause the engine to run under special mode loads, which are prescribed for the various vehicle classes, and the running of the engine

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under the above-described loads for a sufficiently long period of time, which is only too long while it is necessary that the instruments indicating the CO and HC content in the exhaust gas have accepted the final value and these final values have been written out on the report card. The execution of the test and the one required for it Equipment is further simplified by giving the mechanic an auxiliary instrument in the form of a speedometer with a scale whose division represents the road speed in miles per hour and also has colored fields that help the mechanic to maintain the correct speed (load) supported for each prescribed test mode.

Fig. 8 illustrates a typical report card 76 on which the test results of the modes are plotted. The map has a field 78 for the name of the vehicle owner and the identification data of the vehicle under test. on three horizontal lines are printed on the report card 76. The top line contains descriptions FAST, SLOW and IDLE, which are the names of the three test modes for high cruising speed and slow cruising speed and idle correspond. The individual blocks are expediently in the order from left to right arranged in which the individual test modes are carried out.

The second horizontal line 82 contains a first column with the entry of CO content as well as further fields 82A, 82B and 82C under the above labels. These fields 82A-82C contain the permissible ones imprinted Maximum values, such as max 3% under idle (field 82C).

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The third horizontal line 84 initially contains the inscription HC content, which is the content of unburned Corresponds to hydrocarbons. The subsequent fields 84A-84C are under the associated designations as you can read above. In field 84A there is again the highest permissible value of 22 ppm for FAST (= high cruising speed) imprinted. Correspondingly, in fields 84B and 84C, the associated maximum permissible values are found in each case Values of 240 ppm or 290 ppm are printed. A marking indicating the rejection can then be entered in each field when the specified maximum values are exceeded.

The report card 76 also reports the results of tests at loads and speeds relevant to the respective vehicle class are prescribed. According to the entry in the corresponding fields from Fig. 8, it can be seen that of CO content at high cruising speed 0.4, at low cruising speed 0.6 and at idle 2.8 was found. All values are below the permissible values and are therefore acceptable »However the value for the HC content was 1252 at high cruising speed and 1350 at low cruising speed and found at idle on 1482. All values far exceed the permissible values and justify a rejection of the vehicle, which is indicated by the appropriate check mark under each value in fields 84A, 84B and 84C is indicated.

9 shows a report card 85? that of Fig. " 8 similar is, but also a column labeled NO and there is also a fourth line 86, the horizontal the label NO shows »The third and fourth",.-_, = ■ "

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Fields 86B and 86BB leave room for recording NO levels and these should have at least a drop of 35% when the speed is reduced from low cruising speed to idling. Otherwise the detected NO values would indicate that the NO facility is not operating properly or at all not working.

Fig. 10 shows a report card -88 that of the report card 76 is similar, but still has the STARTER column, including fields 88D and 9OD for the determined CO and HC values are available in mode 4. The report card also has lines 92 and 94 in which, if required the test can be repeated for CO and HC.

The report card 96 of FIG. 11 is a composite of the report cards 76, 85 and 88 and enables recording of test data for all four modes as well as testing for NO content.

The use of a fixed load curve according to FIG. 2 is eliminated the need to change the power destroyed by the power destroyer 4. Thus one results extraordinary simplicity in carrying out the tests, as the test mechanic only needs to look at the measuring device, that is the speed in miles developed and simulated by the vehicle wheels on dynamometer rollers 10 and 12 per hour. If the engine is running at the desired speed, then the test mechanic will hold the speed evenly for a few seconds and observes the CO and HC measuring devices 40 and 46 and draws the display values on a report card (Fig. 8). This happens in connection with each mode, i.e. at high Cruising speed, slow cruising speed and idling, preferably also in this travel sequence.

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Operation at high cruising speed corresponds to mode 1 according to the method according to the invention. Of the The speed range for the high cruising speed is indicated on the speedometer 20 by the red field 28 indicated. The load automatically exerted on the engine by the power absorber unit 4 is approximately 27 to 30 hp.

After completing the test at high cruising speed, which only takes a few seconds, the test mechanic lets the carburetor nozzle partially close and carries out the test at slow speed, which test corresponds to mode 2 of the method according to the invention. The speed range for low cruising speed is indicated by the red field 30 on the scale 22 of the speedometer 20 and obviously belongs to the same vehicle class. The power automatically drawn from the engine is about 10 to 12 hp. The test mechanic keeps the displayed speed constant for a few seconds and notes the readings on the CO meter 40 and the HC meter 46 on the report card.

Next, the test mechanic fully releases the carburetor flap so that a test is carried out when the engine is idling, which corresponds to mode 3 of the method according to the invention. The test mechanic observes the CH displays and the HC displays under idle and write it down in the corresponding space on the report card. The ones usually used for the tests The time required according to modes 1, 2 and 3 is less than one and a half minutes and can usually be about a minute be estimated. The invention thus provides an extremely rapid method for checking emissions of automobile engines.

7098 07/0301

When carrying out repairs and settings to correct engine damage, the basic settings only run while idling and make adjustments or repairs made by those idle settings Can not be eliminated, must run after determining the components of the system causing the vehicle damage.

Fig. 12 shows a typical analysis diagram with two Boxes 98 and 100, both showing the possible reasons for rejection due to abnormally high HC emissions. The fields 100 show the rejection marks in fields 100A, 100B and 100C, which correspond to fields 84A, 84B and 84C of report card 76. Thereafter The indicated reason for the excessive HC development during the three modes would be faulty ignition failure of the ignition system. The analysis diagram, together with the report card 76, enables the mechanic to to correct the error very quickly, as the diagram shows not only the type of damage, but also suggests the necessary maintenance measures to remedy the malfunction.

An abnormally high percentage of CH emission is an indication for unnecessarily rich mixture 'and for the delivery of unused fuel. As you know, there is also carbon monoxide another highly toxic gas. Small amounts of the same that penetrate into the passenger compartment, for example due to smaller ones Leaks in the exhaust pipe can result in drowsiness and longer reaction times for the driver. Length inhalation or higher concentration can render the driver unconscious and ultimately even kill him. Thus there is a regression excessive CO emissions to an acceptable level for both safety and economy of the Serve vehicle operation in an excellent manner.

709807/0301

Abnormally high release of HC indicates that an unnecessary amount of fuel has passed through the engine unburned. runs. An abnormally rich carburetor increases the consumption of HC and the emission of fuel; oppose it about normal exposure to CO but very high emissions of HC, usually a faulty ignition or leakage attributable to exhaust valves that allow air and fuel to escape into the exhaust without this Mixture has been burned beforehand. Therefore, eliminating this damage leads to increased profitability and a better running of the engine.

Note that the report cards and the analysis diagrams according to the invention are typical and indicate an error, i.e. excessive HC development in all modes and that however in practical operation the report cards can indicate a rejection of the engine due to other errors and that the analysis diagrams are filled in according to such other errors and thus a wonderful aid to rectification of damage form.

The mode method according to the invention can also be used to test the engine in the event that its power loss should be preferred at which a volume of water in the working circuit by the test mechanic can be varied to accommodate any load within the capabilities of the shredder at a given speed and to repeat the tests exactly · under the same loads and at the same speed. A chassis dynamometer which has a power absorber transfer with the mentioned property shows FIG. 13. The parts that also occur in the chassis dynamometer 2 from FIG. 1 have the same reference numerals. The device 4A differs from the device 4 from FIG. 1

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in that there is a heat exchanger 102 for cooling the Has liquid in the working circuit. Another difference is that they have an inlet valve 104 and a drain valve 106 for changing the liquid medium contained in the working circuit as desired. The capacity of the power consumer 4A therefore changes according to the amount of water in his Work system is included. In order to cool the enclosed water it is necessary to pass it through a heat exchanger runs through, which is itself cooled by another water flow through tubes, not shown, through which the working medium circulates, which is known per se.

If the tested motor accelerates or decelerates during the test, the drive roller can be used 10 of the dynamometer a flywheel 114 may be connected.

The flywheel 114 cooperates with a guide pulley 116, which is attached to the shaft of the drive roller 10. An impeller 118 mounted on a shaft 120 has a Another wave washer 122, which is driven by the drive roller 10 via several belts 124. The flywheel 114 can at your choice with the drive roller 10 via a Mechanism 126 are coupled, which is designed so that he tensions the belt 124 so that the impeller 118 runs with it or is separated from the arrangement, depending on the position of the mechanism is.

A moment arm 108 is between the stator of the power dissipation unit 4A and a force converter 110, so that a torque signal is generated which, after integration a power meter 112 is supplied with the speed signal from the tachometer 16.

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The fourth mode, in which the motor is tested with a full valve (full stator pull), must be tested with a dynamometer that can exert various loads at different speeds, such as this Chassis dynomometer according to Fig. 13. The dynomometer can according to Option coupled to impeller 118 or other device the inertia effect of the various vehicle weight classes when accelerating and decelerating simulated. For testing for emissions from the point of view of air pollution or general improvement However, the three modes described here are quite suitable for running the engine.

The mode method according to the invention for checking the emission can therefore be used to determine the emission of oxides of nitrogen and especially in connection with modern vehicles are used that have facilities for monitoring the emission of NO. The NO emission values are based on the Report cards noted down (Figs. 9 and 11). In addition, other modes and procedures can be carried out if future Control procedures should require this and when special functions are to be checked.

There are currently several devices that allow the emission of NO in exhaust gas to be controlled. Two of these devices

work according to the same procedure, which is based on the principle of delaying the spark advance (pre-ignition), when the vehicle is moving slowly. One of these systems therefore includes a speedometer that determines the spark delay signals below a predetermined speed, such as a speed of about 20 Miles per hour. Other systems use a gearshift that works when shifting to a lower gear Spark delay signaled. A short emission test only needs to verify the NO emissions.

7 09807/0301

adorn whether these controls work or not. Quantitative measurements of NO alone can be sufficient to to check these control units. The term NO relates

Ji

focus on NO or NO + NO-.

To the NO test in the mode method according to the invention for testing and repairing engines, a NO field appears on the report card. The test mechanic

Ji

carries out the special procedure for testing the particular type of control device in the vehicle when it is to comes to the point where the NO test is most practical.

can be performed.

For speed-dependent NO controls, the

Ji

Test mechanic receives an indication of NO from NO measuring device 52

X X

slow cruising speed and reads another display just below the predetermined speed, at which the ignition delay should normally occur. If the NO control is working properly,

Ji

then the NO value should be at least 35% between the long-

Ji

the same speed and the even slower speed mentioned. If such a waste is not occurs, this indicates that the NO controller is not so

Ji

works as it should.

To test the vehicles with gear switch-controlled NO control, the test mechanic observes the NO measurement

X X

gets 52 at low speed and then goes into one with the gearbox while holding the carburetor position lower gear over. If the NO value by at least 35%

Ji

has dropped after switching to the lower gear, works the establishment satisfactory; if such a drop does not occur, it indicates that the NO control does not work as it should.

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As already mentioned, the mode test system according to the invention can be used to measure exhaust emissions on both new and old engines, regardless of whether they Are or are not installed in a vehicle. When testing new or old engines, they are running at an engine speed run that corresponds to the speeds at which they would be operated if in a vehicle would be incorporated that drives at high cruising speed, low speed or idling. To, for example, high To simulate speed, the engine would be at around 1700 to 2200 rpm (corresponding to 3200 rpm for engines running at high speed) run with the motor developing about 35% to 60% (or up to 75% for the small machines) of its maximum torque. In order to simulate slow speed, the motor is running at a speed greater than 40% (and preferably 60 to 70%) of its high speed corresponding speed and less than 50% (and preferably 30 to 50%) of its power run at high speed »

One criterion for the increase at high speed loading is to be the maximum power / speed output "of the engine to approach _s ifährend undergoing the official test." The speeds and torques that fit for all vehicles that require large areas, because of the large differences in the displacement / vehicle weight combinations. For example, a 2.7 liter machine works relatively hard compared to a 7 liter machine with the same driving weight. but this at .dem mode test, picht 4p case be should an "excessive CO Offload at normal combustion to vermeidena pie burdens on a | .le vehicles at the slow speed are chosen such that the s'ie ¹ air flow rate through the engine

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lent reduce compared to the one who is at high speed is present.

Automatic test system

Fig. 14 shows an automatic control system for measuring and comparing the main air pollutants from the Exhaust emissions from an internal combustion engine with acceptable values. The system also provides a printed sheet in the form of a report card showing the engine errors, and if necessary, instructions for a repair mechanic to make the appropriate adjustments or the repair perform.

The automated system is designed to provide optimal speed for the prescribed test modes, hardly any special experience or skill of the test mechanic is required. The tax system is working electronic and includes a mini-computer 150. The computer takes appropriate signals over line 151 from the vehicle identification section on, in which vehicle weight class, type of emission control units that are in the Vehicle are installed, etc. are noted.

The computer also receives signals on line 152 from the control section of the main system, i.e. a data distribution format, automatic or manual decisions about okay / failure and manual or automatic Analysis charts. Signals that represent the completion of the functional tests, such as arming, acceptance of Vehicle NO controllers and so on are fed to computer 150 via line 153. A start test signal that can be entered by a manual switch, is fed to the computer via line 154. A lifting mechanism

for example according to patent application P 24 15 094.5

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can be positioned between the dynamometer rollers 10 and 12 be to lift the vehicle wheels off the rollers to a raised position and the wheels on rollers in the lowered position. Such a jack mechanism allows the vehicle to move relatively quickly on and off the reels. In response to the downward signal on line 154, the Computer a lift lowering command on line 155, whereupon the air mechanism lowers the vehicle wheels on dynamometer rollers 10 and 12 (Fig. 13) and thus the vehicle wheels with it the power annihilation unit 4A couples. In response to a start test signal on line 154, the computer lets the Test sequence off. In response to a raise signal on line 154, the computer issues a lift raise command on line 156 at the end of the test and lifts the vehicle wheels off of rollers 10 and 12.

A reduction gear signal is sent to the computer via a line 157 fed, to the effectiveness of the gear-dependent NO control unit to test. A test repeat signal is fed to the computer via line 158 and allows it Test mechanic to repeat a special test mode. A signal indicating the switched negative pressure advance ignition is received by the computer via line 159 and enables testing of the negative pressure-dependent NO control units.

The computer 150 gives suitable driver instruction board (Fig. 18) via line 160 to the test engineer about the tasks which he has to carry out in accordance with the explanation below. A mode load index meter 166 takes a test speed signal on line 168 from computer 150 and a measured speed signal via line 169. Alternatively, the aforementioned speed

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keitssignal a function of the torque or the destroyed Performance, which will be discussed later. The load index measuring device informs the test mechanic whether the actual exposure is too high, too low or in the right range. Furthermore, the measured speed signal is fed to the computer 150 and enables it to the test engineer to change the speed if this should be necessary. A load comparator 170 takes a speed range signal via line 172 and receives a measured speed signal via line 174, which represents the vehicle speed. The measured speed signal can be obtained from the speedometer generator 16 can be delivered. The comparator 170 provides a load signal on output line 176 when the measured The value of the speed falls within the specific range of speeds (loads) determined by the Computer 150 has been selected for the test currently running, e.g. B. high cruising speed, low cruising speed or idle.

Signals which represent the measured values of the gases under consideration (CO, HC, NO and O ₂ ) are fed to the gas stabilization circuits 178 via input lines 180. The gas stabilization circuits provide output signals on line 182 which represent the stabilized values of the gases being measured. A load gate 184 transmits the stabilized gas signals via output line 185 to gas signal comparators 186 as a function of a load signal from load comparator 170. The stabilized gas signals are further fed to computer 150 via line 188 for recording via line 190. The computer or an external circuit can issue a readout command signal on line 192 to gate circuits 194 in response to receipt of the stabilized gas signals.

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263388U

The gas signal comparators 186 compare the stabilized gas signals with signals fed to the input 187 which represent the acceptable limit values of the gases under consideration. The comparators 186 supply an output signal in order or failure on the output 189 if the measured values of the gases under consideration are below or above the acceptable values. Gate circuits 194 transmit the output signals via line 196 from the gas signal comparators to indicators for OK or failure and to storage elements 198 as a function of read-out commands from computer 150 on line 192. Storage elements 198 store failure signals for each gas (CO, HC, NO and O. ₂ ) in each prescribed test mode as a function of a store command on line 199. An analysis of the gram matrix circuit 200 records the failure signals on line 202 from the storage element 198 at the end of the measurement sequence. Depending on an analysis diagram command on line 204, the matrix actuates a report form printout selector 206 and lets the appropriate report form be printed out or a designated form output, whereby the test mechanic is informed of engine damage and, if necessary, receives suitable repair or adjustment instructions, which will be discussed further below .

Note that a separate gas stabilizer 178, load gate 184 t ^e in gas signal comparator 186, and output gate circuit 194 are provided for each gas to be measured which is compared to predetermined limits as discussed below.

15 shows an exhaust gas analyzer with a CO analyzer 66, HC analyzer 68, NO analyzer 70 and O ₂ analyzer 210. The oxygen analyzer 210 contains a measuring device 212

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Pointer 214, which moves over a suitable scale, which has graduations from 0 to 25, which indicate the percentage by volume of oxygen in the exhaust gas. The remaining parts of the exhaust gas analyzer, ie the CO, HC and NO analyzers, have the same reference numerals as those of the corresponding components from FIG. 3. The exhaust gas analyzer provides output signals on lines 216, 218, 220 and 222 which carry out the quantitative measurements the exhaust emissions of CO, HC, NO and O ₂ .

The output signals from the exhaust gas analyzer are converted into digital signals by circuits shown in FIG. The CO, HC, NO and O ₂ signals are amplified by amplifiers 217, 219, 121 and 223 and supplied to analog / digital converters 224, 225, 226 and 227 - as shown. The analog signals representing the measured values of CO, HC, NO and O ₂ are output on lines 230, 231, 232 and 233. The digital signals representing the measured values of CO, HC, NO and O ₂ are output on lines 234, 235, 236 and. Analog signals from the speedometer or tachometer generator 16 are fed to an amplifier 240 and an analog / digital converter 241 on line 238. An analog signal representing the measured values of the speed of the vehicle will arrive on line 242 and a digital signal representing the measured speed is provided on line 243.

According to Flg. 17 become the vehicle identification signals, the setting controls and the functional test completion controls and enable the test mechanic to provide the computer with information relating to the specific dynamometer load to supply, which is necessary for each test mode,

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also the acceptable limits of air pollutants, etc. The vehicle identification controls include a vehicle class selector in the form of a six position rotary switch 245 with a manual rotary knob 246. The vehicle class is preferably selected based on the vehicle weight, but the engine displacement can also be used or another property as desired. The vehicle identification selector 245 informs the computer about the special dynamometer load for each prescribed test mode of the machine with the exception of the Idle. As discussed above, the power dissipation unit 4 or 4A provides a load that is substantially with the cube of the speed changes. In preferred embodiments, therefore, the correct one Dynaometer load adjusted by adjusting the speed of the driven roller. For testing vehicles under current standards, only four positions of the class selector 245 need be used, the correspond to the vehicle weights according to table A;

TABLE A

Voting positions

Vehicle weight Vehicle class in t

A B C D E + F

over 1.7 1.3 - 1.7 under 1.3 under 1.3

U.S. Heavy and Ordinary Vehicles, Imported Cars

Compact and medium-sized vehicles, imported cars

Small cars, small imported cars with automatic

Small cars, small imported cars with manual transmission

Clipping for further categories

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The preselected speeds, which correspond to each vehicle weight category according to Table A above, will be discussed in detail herein with reference to the load index meter in FIG.

A three position rotary switch 247 with a hand knob 248 enables the distinction between engines with 4, 6 or 8 cylinders. The switch has three positions, one of which is the four-cylinder engine, the other the six- or eight-cylinder engine and the third designate all engines.

A five position rotary switch 250 with a rotatable Hand knob 251 enables the correct year of the tested vehicle to be selected. This choice informs the computer about the gas values that are acceptable for this vehicle year and that are required when testing the vehicle. For example, the switch position "NONE" indicates that the vehicle is not monitoring emissions or the like owns, which applies e.g. to vehicles in California that are older than 1966 and to vehicles in the other states of the United States that are older than 1968. The position 1 of switch 250 applies to vehicles equipped with the first generation of emission controls, for example for the models from 1966 to 1970 for California and 1968 to 1970 for the other parts of the United States. Switch positions 2 and 3 refer to the second and third generation of the Emissions controls, which will be discussed later. Switch position 4 can be used for vehicles those with future generations of emission control devices will be equipped.

709807/0301

A two-position rotary switch 252 with a rotary knob 253 enables the information to be entered into the computer, whether the vehicle to be tested has a pump for injection of air into the exhaust gas flow (position "YES"). The position marked "NONE" applies for those vehicles that are not equipped with any device that allows air to be injected into the exhaust enables. Vehicles with an air pump for the exhaust system usually require a lower standard for exhaust emissions in idle mode because of the resulting dilution of the exhaust sample.

A six-position rotary switch 254 with a hand knob 255 allows the specific type of nitrogen oxide control device installed in the vehicle to be set. The "NONE" position applies to vehicles that do not have any NO controls, i.e. the models before the year

1971 in the state of California and the models before 1973 in the rest of the United States. the The "TSAD" position applies to vehicles that are provided with gear-actuated advance ignition delay, i.e. those Vehicles with advanced ignition delayed in low gears. The position marked "SSAD" applies to vehicles that have an advance ignition delay, which depends on the vehicle speed. the The "SAD" position refers to vehicles whose pre-ignition delay is not influenced by either the transmission or the vehicle speed depends. The "EGR" position is reserved for vehicles that are equipped with an exhaust gas recirculation system, and the "BOTH SAD AND EGR" position applies to vehicles with both pre-ignition retardation and are equipped with an exhaust gas recirculation system. The function of the NO selector switch 254 is to give the computer input

signals to the respective NO monitoring device to test what will be described in detail.

709807/0301

A three-position rotary switch 258 with button 259 enables entering information to the computer regarding the type of catalytic converter, if the vehicle to be tested is equipped with it. The "NONE" position applies to vehicles that do not have any have catalytic afterburner. The "HC / CO" position applies to a first generation of vehicles equipped with catalytic afterburners, which the salary want to reduce hydrocarbons and carbon monoxide. The "NO / HC / CO" position applies to a second Generation of catalytic converters, with which the vehicles are equipped, also for the reduction the content of the gases mentioned are provided.

The main setting controls for the computer are shown in Figure 17 and include an on / off switch 260. A rotary switch 262 with button 263 for data distribution enables the computer to be controlled in such a way that (1) in the "MAN" position, the data can only be read manually on the gas analyzer, (2) in the position "PRINT" the measured and acceptable values of each of the gases under consideration are printed out for each test mode,

(3) In the "COMP" position, the data obtained by the gas analyzers are sent to the computer for automatic comparison with the acceptable values, etc., and

(4) In the "BOTH" position, the data is printed out and sent to the computer.

A three-position rotary switch 265 with button 266 enables the computer to be programmed so that an automatic Comparison of the measured and acceptable gas values is obtained and that output signals about the passing or failure of the test for any gas in any test mode in the "AUTOPASS / FAIL ONLY" position will. In the "AUTO PASS / FAIL WITH DATA

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ACQUISITION "the computer generates output signals indicating successful or unsuccessful passing, and the actual values of the gases in each test mode would be accepted for recording, etc. In the position "MAN", the switch 265 programs the computer for manual data acceptance and comparison with acceptable ones Values.

A two-position rotary switch 268 with button 269 enables programming the computer for manual (MAN) or automatic (AUTO) analysis chart identification.

An indicator light 270 (Fig. 17) informs whether the dynamometer consumed the desired energy or not. The light 271 indicates that the instrument parameters have been calibrated and testing should not be undertaken.

The functional test completion panel of Figure 17 includes a DISARMED push button switch 272 and an ARMED push button switch 273, so that the computer can be informed by actuating the respective switch whether the NO control unit the vehicle is dismantled or installed. A vacuum system according to FIG. 23A is intended to be the vehicle vacuum system with the suction opening 275 from FIG.

A push-button switch is used to check vehicles for leaks or leaks in the exhaust system or for exhaust dilution 280 is provided with which the computer is informed that the exhaust pipe by blocking a part its outlet was pressurized, which will be discussed below. A repeat switch informs the computer that the previous test should be repeated to take gas measurements without dilution obtain. A cylinder short circuit switch 283 informs

70 9 807/0301

the computer that a cylinder has been short-circuited to the effectiveness of a catalytic converter or afterburner to test.

According to FIG. 18, a driver instruction board light 290 and 291 and, when they light up, inform you that the vehicle is in direct gear (high gear) or should be in a lower gear. The panel includes lights 292, 293, 294, 295, 296 and 297 that focus on the Obtain NO function test. The lamp 292 informs that the next lower gear is being engaged target. Light 293 indicates that the nozzle (accelerator pedal) should be reduced (withdrawn) in order to avoid the movable one To bring pointer 307 into the "ON" zone of the load index meter 166. Lights 294 and 295 indicate when they are lit. indicates that the exhaust gas circulation system is to be removed or installed. Lights 300, 301, 302 and 498 refer on the exhaust gas dilution tests. Light 300 indicates that the exhaust pipe needs to be pressurized. Lamp 301 indicates that the exhaust pipe has been pressurized. Light 302 indicates that the test should be run again is because the vehicle exhaust system has a leak, and Light 498 indicates that the exhaust sample analyzer should be repaired and retested. lamp 303 indicates that all tests are complete.

The load index meter 166 according to FIG. 18 has a center display and is from the D ^! Arsonval type with two pairs of input terminals 305 and 306. The meter responds to DC signals that are proportional to speed, torque, or power. In the preferred embodiment, the signals are proportional to speed. The meter pointer 307 is centered when the amplitudes of the signals applied to input terminals 305 and 306 are equal. When the terminal 306 supplied

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Input signal is greater than that of the input terminal 305 applied input signal, then the measuring device pointer moves to the right into the one labeled "OVER" Zone, and if the input signal applied to port 306 is less than that applied to port 305 Is the input signal, the pointer moves to the left into the zone labeled "UNDER". One of the vehicle speed proportional direct current signal is fed from the tachometer generator 16 to the measuring device connection 306, and a direct current signal proportional to the desired speed is fed from the computer via line 168 is supplied to the connection 305. If thus the measured speed is the desired speed equals in a certain test mode, the measuring device pointer will be in the middle zone, which is with "ON" is designated. This zone can mean any desired speed range, for example 3 MPH.

If the measuring device pointer is within the "ON" zone, a computer triggered light 308 will illuminate indicating that constant speed has been maintained shall be. A light 309 when it lights up informs that the speed should be changed so the meter time comes back to center and a lamp 310 lights up to indicate that the current Accelerator pedal position should be maintained regardless of the speed.

Table B below lists typical speeds that should be used with a power dissipation unit having a power / speed characteristic as indicated in Figure 2 for the three categories of vehicles at fast cruising speed, slow cruising speed, etc.

7 0 9807/0301

TABEL

Vehicle-
Class (t) miles
per hour
fast miles
per hour
slow miles
per hour idle over 1.7 49 34 15th zero 1.3-1.7 45 31 15th zero below 1.3 37 24 15th zero

The speeds listed in Table B are of course only to be understood as examples. The respective speed for a test mode depends on the power dissipation unit and the desired engine load.

When idling, the vehicle brakes must be applied to prevent the dynamometer rollers from operating the automatic To turn gear in the direct range. If there is no compensation voltage at the measuring device connections 305 in the idle mode is applied, the pointer would go beyond 1 to 1 1/2 MPH from the "ON" zone. This is considered to be satisfactory as the brakes are applied or not. If not, the speedometer pointer will be in the range Be "OVER" to remind you that the brakes should be applied.

19 shows a portable commander for use by the test mechanic while seated in the vehicle pressed the accelerator pedal. The command generator 311 comprises a pressure switch 312, with which the computer 150 via line 154 it can be informed that a lift lowering command signal on line 155 to lower the lift that carries the powered wheels of the vehicle lowers the dynamometer rollers. A push button switch 314 signals the computer on line 154 when actuated

70 9 8 07/0301

to start the tests. A switch 315 is for the Tests are provided by the NO control devices and informs the computer 150 via a signal on line 157 which is a lower Gear was chosen. Switch 316 can be operated by the driver to remove the lamp 294 (FIG. 18) of the negative pressure advance ignition to light up. A switch 317 is operated by the test mechanic and informs the computer that it is going through a retest procedure should proceed as he should deem necessary. When the switch 317 is pressed, the repeats Computer the last test. A switch 318 is actuated upon completion of the tests and sends a raise air command signal to the computer on line 156 which raises the lift and allows the test mechanic to do the Drive the vehicle off the dynamometer rollers.

Fig. 20 shows memory elements 320 to 346, 503, 507, 507 ' and 514 contained in the memory of the computer. the Storage elements 320, 321 and 322 provide output signals that indicate the high cruising speed and the upper limit of the high cruising speed and the lower limit speeds for the respective class of the tested vehicle deliver. Storage elements 323, 324 and 325 provide output signals, the slow cruising speed and the upper and lower speed limit for the slow cruising speed deliver. The specific values of the signals supplied by the storage elements 320 to 325, depend on the vehicle class. Storage elements 326, and 328 provide output signals which are the acceptable limit fpr CO at high cruising speed, the acceptable limit for CO at low cruising speed, and the acceptable Represent limit for CO at idle. The storage elements 329, 331 and 333 provide output signals which are acceptable Limits for HC at high cruising speed, lower

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Represent cruising speed and idling. The storage elements 330, 332 and 334 provide output signals, which lower the acceptable limit for HC times a predetermined value such as 150% at high cruising speed Represent cruising speed and idling. Elements 335, 336 and 337 produce output signals that are acceptable Represent limit values of NO at high cruising speed, low cruising speed and idling. The storage elements 338, 339 and 340 provide output signals, which is the percentage limit values for NO (for TSAD and SAD tests), the upper speed limit for NO control (for SAD tests) and the acceptable limit for NO (for SSAD tests

Tests). The O ₂ limit values for high cruising speed, low cruising speed and idling are provided by storage elements 341, 342 and 343. Storage element 344 supplies signals which represent the percentage limit value for CO for vehicles which are equipped with an injection pump for air into the exhaust gas. Element 345 supplies a signal which represents the percentage limit for the negative pressure increase for vehicles which are equipped with SAD- Controllers are equipped. Element 346 provides a signal indicating the percentage limit for NO for vehicles

Ji

that are equipped with control units for NO ERG

are. Element 503 represents a preset percentage of CO to provide an indication of the expected _{amount of O 2} that can be expected based on stoichiometric considerations for engine operation. Elements 507, 507 'and 514 relate to the percentage limit values of Oj and the percentage change _{limits of O 2} , which will be explained in connection with FIGS. 27 and 27A.

It was considered that the specific values of the acceptable limits for the air pollutants in the exhaust gas emissions of are dependent on the standard values that are officially prescribed

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and change from time to time. Among the present valid standards are the permissible air pollutants of an automobile, for example determined by the model year. Tables C, D and E listed below are suggested standard values for HC, CO and NO for three particular ones Groups of automobile years given.

Proposed standard values for introduction in a test workshop in California for compulsory exhaust emissions inspection tion for vehicles

TABLE LE C

Vehicles of the years of construction 1965 and earlier

Idle slow speed high speed HC CO HC CO NO _x HC CO 1300 9.5 1000 6.0 2500 1000 5.0

TABLE D Vehicles built in 1966-197 0

Idle slow speed high speed HC CO HC CO NO „HC CO

700 7.5 500 5.0 2500 500

4.5

709807/0 3 01

TAB. ELLE E

Vehicles built between 1971 and 1974

Number of idle HC idle CO ^% longitudinal travel- high travel.ZyI. speed speed.

AI other AI other HC Co No HC CO 4 400 500 4.5 6.0 350 3.5 2500 350 3.0 6 and 8 250 350 4.0 5.0 250 2.5 2500 250 2.0

The values in the tables above are parts per million (ppm) for HC and NO and for CO % of the total exhaust gas flow. As indicated in the tables above, the values are the acceptable limits for the air pollutants determined by the computer correspond the settings of the controls, which are designated under the emission control types and perhaps with the number the cylinder as discussed above in connection with FIG. 17. The designation AI in Table E refers to those vehicles which are equipped with systems for injecting air into the exhaust systems.

Operation of the automatic test system

In preparing for a vehicle test, the test mechanic sets the vehicle identification controls shown in FIG. 17 that correspond to the vehicle to be tested. The test mechanic also sets the right system SETTIN ..- ran to the data acquisition by the computer, the AUTOMATIC • -.en comparison of air pollutants with the acceptable values, a record of the actual values for each test mode and to have so forth. Assume that the vehicle identification controls are set and correspond to the vehicle to be checked c "- * and that the main system controls are se

709807/0301

are taken that they (1) a data distribution for the computer and for the printing unit, (2) automatic OK / ERROR DECISIONS with the data acquisition (3) result in automatic analysis diagram identification, ' the test of the vehicle can then begin. The test vehicle is driven on the dynamometer rollers and the lifts lowered by actuating switch 312 on the control panel (Fig. 19). The gas analyzers are then switched in such a way that that they can take a sample of the vehicle exhaust (Fig.15). The driver or test mechanic presses the test switch 314 on the driver's control panel. Depending on the associated signal, the computer activates the light in the transmission section of the driver command device according to FIG. 18 and informs the test mechanic whether he perform the test in direct gear or go down a gear.

The test engineer starts the vehicle so that its wheels spin by depressing the accelerator pedal. According to attitude of the vehicle class switch 245, the computer selects the correct speed for the test at high Cruising speed, i.e. the correct output signal from the storage element 320 (Fig. 20) for ^ high cruising speed, and outputs this signal to input 305 of the load index meter 166 (FIG. 18). Now the computer activates the light 309 which tells the test mechanic that the speed should be changed. The test mechanic depresses the accelerator pedal until the pointer of meter 166 is in the "ON" range. Then the computer switches the light on 309 and illuminates light 308 which instructs the test mechanic to keep the pointer constantly within range Keep "ON". The vehicle is now in high cruising mode.

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Fig. 21 shows the circuit parts by which the measured values of CO, HC, NO and O _{9 are} compared with the acceptable values. The circuit parts from FIG. 21 can serve to supply a signal representing the passing or failing of the test for each gas under consideration, with or without data accumulation of the measured values in each prescribed test mode. The circuits for performing the test of the operation of the NO controllers will be discussed later

Ji

described. If the official standards do not prescribe an evaluation of the amounts of NO or O ₀ in the exhaust gas at high speed, low speed or idling, then the associated circuit parts of FIG. 21 are not used during these tests.

The signal representing the measured speed (load) from the tachometer generator 16 on line 243 is compared with a signal that represents the upper limit speed and lower limit speed, the comparison being carried out in a subtracter 360, -der provides an output signal (i.e. high signal level) if the measured signal has a value between the mentioned limit signals owns. The dual subtracter 360 can be of the type described in patent application P 24 15 094.5 (C 50) is described. The output line to the timer circuit 362 corresponds to the output M in the present r Description. The inputs to subtracter 360 connected to storage elements 321 and 322 are used here occasionally collectively as the reference speed initial range designated. The output from the subtracter 360 is fed to a timer circuit 362 and a gate 363 supplied. The timer circuit opens gate 363 only after the subtracter 360 continuously outputs an output has produced continuously over a predetermined time interval, i.e. over 1 to 5 seconds. That Gate 363, when prepared, transmits the output from subtracter 360 to CO speed gate 364,

709807/0301

which forwards the input signal to the output. The output from gate 363 is sometimes referred to as the speed trip signal. The speed trip signal is also applied to gates 365, 366 and 367 for Hc, NO and O ₉ .

The measured C, HC, NO - and 0 ₀ signals are fed to the stabilizing circuits 370, 371, 372, 373. The stabilizing circuits transmit the measured gas signals to the associated speed gates only after these signals have stopped fluctuating within certain limits over a predetermined time interval in order to ensure that the signals represent a reliable quantitative measurement of the respective gas in the exhaust gas. An example of such a bar optic circuit is shown in Fig. 31 and Fig. 31 and will be described later.

An example of such a stabilizing circuit is illustrated in Figs. 31 and 32 and will be described later.

The stabilized gas signals from stabilizer circuits 370, 371, 372 and 373 are fed to subtractors 380, 381, 382 and 383 through gates 364, 365, 366 and 367 as shown. Gate 364 is opened by the speed trip signal and transmits the stabilized CO signal to subtracter 380. Gates 365, 366 and 367 are opened by the appearance of both the speed trip signal and the stabilized CO signal and transmit the HC signal. , No- and 0 >> ^fc signals to the respective subtractors.

X German

Before comparing any of the gas signals to acceptable limits, the speed measured by the tachometer generator 16 must be within the preset range (e.g. 3 MPH) over a given time interval (e.g. 2 or 3 seconds ) ver

OR ₅ GWA IMSPECTED

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2833880

stay and the CO signal must have stabilized. The subtractors 380, 382 and 383 each contain a pair of output lines labeled P and F are. The subtractors can be of the type described in German patent application P 24 15 094.5 (C 50) are described by reference numeral 693 in FIG. 34. The subtractors 380, 382 and 383 compare the respective ones stabilized gas signals with preset acceptable limits stored in storage elements 326, 335 and 341 are stored. Each subtracter supplies an output signal (high level) a) on output line P, if the measured gas value remains below the acceptable limit value given by the signal from the respective storage element and b) on output line F if the measured gas signal is above the acceptable limit lies.

The subtracter 381 is a dual subtracter and can be derived from the be of the same type as the dual subtracter 360 except that it has three output lines P, M and F. An output signal is given on line P when the The stabilized HC signal is below the acceptable limit value set by the signal from memory element 329 is represented. An output signal is generated on line M if the measured HC signal is greater than the acceptable one Limit value, however, is smaller than an average value (i.e. 150% of the HC limit value), which is caused by the signal the memory element 330 is represented. The output on line F appears when the measured HC signal exceeds the signal from storage element 330. The M output from the subtracter 381 is combined with the Output signals on lines P and F from subtracter 380 to a pair of AND gates 385 and 386 as shown given. The output signals P and F from the subtracter 381 are given to OR gates 387 and 388. From-

709807/0301

Outputs of OR gates 387 and 388, ^{labeled P 1} and F ¹ respectively, represent the input signals to a gate circuit 391. A high level signal appears on line P 'when the measured value of HC

(1) is below the acceptable limit (storage element 329), or (2) is above the acceptable limit but below the preset gain (i.e. 150%) determined by the contents of the storage element 330 and when the measured value of CO is its acceptable Exceeded the limit. A high level signal appears on line F ¹ when the measured value of HC (1) is between the acceptable limit and the preset increment (contents of memory element 330) and the measured value of CO is below the acceptable limit, or when

(2) the value of HC is above the acceptable limit and is above the preset gain.

Check gate circuit 390, 391, 392 and 393 with appropriate preparation by the delay networks 394, 395, 396, 397 the output signals from the subtracter and activate lights on the existence or non-existence of the Tests (marked with P and F) depending on a high level signal on line P or F from the respective subtractor.

The lights which indicate the failure or the pass for each throttle and each test mode including full throttle are shown and have corresponding reference numerals in FIG. 29, which will be explained later. The delay networks 394 to 397 take the respective stabilized gas signal from the gates 364 , 365, 366 and 367 and open corresponding gate circuits shortly after the stabilized gas signal has been fed to the respective subtracter in order to ensure that the output signals from the subtractors are accurate Comparison of the respective

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Represent gas with acceptable limits. The gate circuits 390, 391, 392 and 393 can be of the type which are designated by reference numeral 446 in German patent application P 24 15 094.5 in FIG.

The signals from the gate circuits indicating the failure are applied to the computer from memory in storage elements 400, 401, 402 and 403. The actual Values of the stabilized gas signals are also fed to the computer for a printout.

The method of measuring by comparing CO and HC (NO and O ₉ if desired) with the acceptable limits and making pass or fail decisions indicating which of the gases has exceeded the acceptable limits is performed with the apparatus of Fig 21 in test mode slow and idle repeated. If desired, these gases can also be tested at full throttle. In the slow mode, the speed range signal supplied to the dual subtracter 360 will encompass that for the respective vehicle class as shown in Table B. If the vehicle is equipped with an NO control device, then the operation of the device can be checked, which will be discussed below, before going into idle mode. In the idle mode, the speed should be ZERO and the test mechanic will apply the brakes, preventing the dynamometer rollers from turning. The dual subtracter 360 is provided with computational reference signals in the idle mode representing a speed of 0 to 1 or 2 miles per hour.

In the slow and idle mode, the measured Values of NO and CO for estimating the effectiveness

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2833880

of the NO control unit with which the vehicle is equipped, '

and saved for use during the oxygen test. The pass-fail signals are for everyone Test mode saved and are used at the end of the test in an analysis diagram matrix 200 (Fig. 14) to a printed Issue a report to inform the test mechanic about the damage and instructions for repair and / or setting, which will be discussed in connection with FIG. 30.

CHECKING THE NO CONTROL UNITS

Although the device described here enables the NO values can be collected in each mode used and the vehicles assessed according to a specified standard it is clear that the NO can be higher than a critical norm for reasons other than a defect in the NO controls. If the NO-

X X

Control devices working in the correct way will perform the correction the CO and / or HC-related errors and / or incorrect settings, the individual vehicles on their constructive Limits for the emission of all three gases are returned, so routinely by the usual vehicle repair shops nothing further should be done to reduce the NO ^ emission. However, if the NO control units

X X

do not work properly, their correction and repair can be carried out routinely. The one from a repair shop The time and equipment required to routinely determine the status of the NO control devices is for some Vehicle types extremely high. It is therefore relatively likely that this determination will be omitted.

On the other hand, if a periodic inspection of the vehicles is on their control units for monitoring the total exhaust emissions

709807/0301

is carried out, the determination of the function of the NO control unit as part of the procedure described below with the aid of the Device to be executed. Because of the large number of different types of NO control units, the explanation unfortunately make the device a bit complicated. In practice, however, a certain vehicle is only operated in that way tested on NO control units that are built into it.

VEHICLES WITH TSAD DEVICE

22 shows a circuit for assessing the effectiveness of a gear-operated, early ignition-retarding NQ control (TSAD). When the selector 254 of Figure 17 is rotated to the TSAD position, the computer will erase Completes the low speed test light 308 and illuminates light 310, causing the test mechanic is notified that he should hold the accelerator pedal position. Now the computer also activates the light 292 of Fig. 18, which tells the test mechanic that the next lower gear is to be engaged. Then actuated the test engineer presses Done button 315 on the control unit 311 (Fig. 19). After a short time delay to adjust the sample response time, the analyzer opens the computer enters a gate 410 (Fig. 22) and thereby transmits the measured NO R signal to a subtracter 412. The subtracting device 412 compares the stabilized NO signal, which was measured after the gear was lowered, with a preset percentage (e.g. 65%) of the NO signal stored in memory element 414 during the low Speed tests mode has been saved. The stored NO signal is in the divider 415 with a preset NO percentage limit value (e.g. 65%) in the storage element 338 multiplied. The divider 415 can be derived from the

7098 07/0301

in the form shown in Fig. 17 of said application be"

The subtracter 412 produces an output signal on line ■ direction P if the measured NO signal is less than that

NO signal that is stored at low speed χ

and was multiplied by the preset NO limit percentage, which indicates that as a result of the lower gear, the NO / gas content has decreased by the predetermined percentage of, for example, 35%. The subtracter 412 produces an output on line F when the sensed NO signal exceeds the output from the divider 415. A gate circuit 416 is opened by the output signal from gate 410 after a short time delay via delay circuit 417 and activates (1) a "pass" indicator light 418 as a function of an output signal on line P, or (2) a "not be status ¹¹ indicator light 412 depending on an output signal on line F.

When the decision is complete, the computer goes to the next test mode (usually idle) by instructing it to do so to the test mechanic (Fig. 18). Light 292 is extinguished and lights 290 and 309 light up and tell the test mechanic to change gears and speed.

VEHICLES WITH SAD CONTROL UNIT

Fig. 23 shows a circuit for judging the operation of a vehicle, what with an advance ignition delay (SAD) is equipped to reduce the content of nitrogen oxides. When the NO selector 254 (Fig. 17.) is in the with

709807/0301

SAD-marked position, the calculator will look after the Slow speed test (a) light 310 for holding the accelerator pedal and (b) light 294 Switch off the negative pressure advance ignition and light up. The test mechanic disconnects the vacuum hose from the ignition distributor (sometimes referred to as the ignition timing regulator) on the downstream side of the vacuum delay unit and connects the negative pressure source of the engine to the inlet port 27 5 for measuring the negative pressure (Fig. 17), whereby the increase in negative pressure is measured. The test mechanic presses when this is complete Separation work the switch 272 regarding NO shutdown according to FIG. 17.

According to FIG. 23a, a negative pressure signal converter 424 is in the Internally connected to the opening 275 via a solenoid valve 422. The converter 424 generates an analog signal that corresponds to the The vacuum present in the engine vacuum hose is proportional, the hose normally being connected to the ignition distributor connected is.

The solenoid valve 422 in the form of a two-position valve connects in its rest position shown in dashed lines the opening 275 and the engine vacuum hose with exhaust air. Depending on the actuation of switch 272 (Fig. 17) the computer activates valve 422 and connects transducer 424, vacuum meter 274 and a vacuum switch 466 with the vehicle vacuum hose via opening 275. The internal volume of the connection line between opening 275 and engine vacuum hose as well as the components 424, 274 and 466 including the respective connecting lines should approximate the internal volume of the typical engine ignition

709807/0301

distribution system correspond, namely between the vacuum delay unit 421 and the vacuum actuator 424. It should be noted, however, that differences of said volumes by using a suitable delay or negative pressure rate of the rise limit value in the circuit of Fig. 23 can be compensated. The rate of vacuum change at transducer 424 should be approximately equal to the rate of vacuum change that would normally be found at the vacuum ignition manifold.

The vacuum switch 466, which is described in detail in connection with Referring to Fig. 25, is a double pole changeover switch-The moving contacts of switch 466 are biased and is operated by a diaphragm connected to the vacuum line as shown. The desk 466 has output lines labeled P and F and provides a high output level on line P or F if the negative pressure at the opening 275 does not exist or is present.

According to FIG. 23, the signal from the converter 424 is fed to a differentiating circuit 425 When the switch 272 (Fig. 17) is actuated, the computer delivers a NO deactivated confirmation signal, which (1) indicates the Solenoid valve 422 is activated so that transducer 424 is connected to the vehicle vacuum source, (2) the differentiating circuit 425 is actuated and (3) by a time delay device 429 a gate 426 in adaptation to the gas sample response time opens. The differentiated negative pressure signal is converted into a digital signal with the aid of an analog / digital converter 427 implemented and compared by means of the subtracter 430 with a signal which is stored in the storage element 345 and a preset maximum limit of the vacuum rate of rise represents. Subtract unit 430 provides an output on (1) line P when

709807/0301

the vacuum slew rate is less than the preset limit, and (2) on line F if the negative pressure increase is greater than the specified limit.

A memory and priority circuit 434 which is approximately from may be of the type shown in Fig. 30 of the cited application, is between the subtracting unit 430 and an output gate circuit 432 is switched. The memory and priority circuit 434 then provides an output signal each time on line F when there is an output on line F from subtracter 430. Thus becomes supplied a high signal on line F from memory and priority circuit 434 to gate circuit 432; when the maximum rate of rise of the measured negative pressure signal exceeds the preset limit value from memory element 345 exceeds. An output signal on line F from gate circuit 432 is fed to an OR circuit 435 and activates a bad indicator light 436 indicating that the SAD-NO control is incorrect is working.

An output signal on line P from the gate circuit 432 is fed to an input of an AND gate 437. The SAD controller will only pass the test successfully if the maximum rate of vacuum increase is less than the pre-stored amount and the NO signal drops by a preset amount,

which will be explained later.

During the time during which the rate of rise of the negative pressure with the preset limit value is compared, the measured NO signal is compared with the NO

709807/0301

Signal compared to that during the slow speed test stored in element 414 to determine whether the NO gas content has increased by a predetermined percentage has decreased by, for example, 35%. This comparison is performed during the slow speed test stored NO signal with the preset NO limit percentage (e.g. 65%), which is stored in element 338

chert is multiplied by a divider 442. The output of divider 442 will match what is just present NO signal in a subtracting unit 444 compared. the

Subtracting unit 444 gives an output signal on line P if the current value is less than the predetermined value Percentage (e.g. 65%) of the NO gas at slower

Speed, and gives an output signal on line F, when the current NO value exceeds the preset percentage of the stored NO value. A gate circuit 445 is opened after a short time delay by means of delay unit 447 and delivers (1) an output on line P to AND gate 437 in response to an output on line P which Subtract unit 444 and (2) an output on line F to OR gate 435 in response to an output on line F from the subtracting unit. A high output on line P from each gate circuit 432 and 445 activates an indicator light 438 for passing the test via AND gate 437. Thus, a SAD-NO control unit is only considered to be in order

displayed when the speed of the negative pressure increase is less than the specified limit value and the content of NO gas drops by a predetermined amount, e.g., 35%, from the low speed value. the not-okay signals from the gate circuits 432 and 445 are fed to the computer for recording, so that the specific reason for the failure of the SAD control unit

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can be specified.

Upon completion of this decision, the computer will extinguish lights 294 and 310 (FIG. 18) and light 295 will illuminate leave, and thus demand that the SAD control unit of the vehicle is put into action. This is achieved by that the vehicle vacuum source is reconnected to the ignition distributor. After making this connection the test mechanic indicates to the computer that he has done this by turning the on switch 243 (according to FIG. 17) presses. The computer will now let the lamp 295 go out and move on to the next program mode.

VEHICLES WITH EGR DEVICE

When the NO selector switch is in the position marked EGR

Ji.

stands and indicates that the vehicle is equipped with an exhaust gas recirculation system (EGR) is equipped, the NO control unit is tested with the aid of the circuit from FIG Operating procedures that take place in the SAD control, with the exception of lights 296 and 297 (Fig. 18), which relate to the Obtain exhaust gas circulation and from the computer instead of the negative pressure pre-ignition lights are activated, the memory element 346 (FIG. 20) also being used by the computer instead of element 338 is used. The associated circuit is shown in Fig. 24. The engine vacuum hose, normally connected to the EGR valve is disconnected and the engine vacuum source is connected. In this test the engine vacuum source does not need to be connected to the inlet opening 275 for the vacuum meter (FIG. 23a).

When the engine vacuum source is connected, the test mechanic presses the NO disconnected switch 272 (Fig. 17) and confirms to the computer that the vacuum source is from the EGR valve

709807/0301

was separated. The computer delivers a NO -departed confirmation signal via the delay network 429 'which is sufficient to the sample response time of the analyzer system is adapted to a gate 426 ', so that the currently valid NO signal is an input of a subtracter 444 'can be fed. The NO signal, which is due to the low speed in the memory element 414 is saved with a preset NO limit percentage, stored in element 346, multiplied by a divider 242 '. The resulting signal is fed to the other input of the subtracting unit 444 ". In this case, the preset NO limit-

values greater than 100%, for example 120%, since NO will increase instead of decrease in the separated exhaust gas circulation system. A gate circuit 445 'samples the output lines from the subtracter 444' and activates either one OK light 450 or a not OK light 451 if the present NO signal exceeds the preset Amount of the stored NO signal at low speed exceeded or remained below this value.

Upon completion of this decision, the computer will extinguish lights 296 and 310 from FIG. 18 and light 297 will illuminate request that the EGR control of the engine be operated. This is done by reconnecting the engine vacuum source achieved with the EGR valve. After making this reconnection, the test mechanic shows the computer indicates that he did this by pressing the connected switch 273 (Fig. 17). The computer will then let the light 297 go out and move on to the next programmed mode.

OBlGtNALlNSPECTED

709807/0301

VEHICLES WITH EGR AND SAD CONTROL UNITS

When the NO selector 254 is set to indicate

that the engine is equipped with both EGR and SAD, the tests described for SAD and EGR control units are carried out separately.

VEHICLES WITH SSAD CONTROL GEAR T

A circuit for testing the operability of a speed-dependent, advanced ignition-retarding NO control (SSAD) is shown in Figure 25. This test is normally run after the slow speed test is complete executed. If the NO selector 254 is in the SSAD position

ment, a T is inserted into the engine vacuum hose leading to the distributor inlet, where the branch of the T is connected to the vacuum inlet 275 (Fig.17). After completing the low speed test the computer changes the test speed signal supplied to the load index meter 166 to one a suitable value such as 15 miles per hour (Mph). The computer also operates the lamp 309 (Fig. 18) and thus informs the test mechanic to change the speed. The measured speed signal is linked to an upper limit signal for the speed from the memory element 460 and a lower speed limit signal from the memory element 461 in one Dual subtracters 462 compared. The dual subtracter gives an output on an output timer 464 when the measured speed is within the desired Speed range is, for example, 15 mph plus or minus 1-1 / 2 mph. Of the Timer 464 outputs an actuation signal to a gate circuit 465 after a predetermined period of time (e.g. 5 Seconds) after receiving an output from the dual subtracter 462, thereby allowing the output

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263388Q

signals stabilize. A vacuum switch 4 66 produces a high level output on line F, this indicates that the distributor vacuum is present. A high level signal is on output line P of the vacuum switch 466 present when there is no ignition distributor negative pressure. The output signals from switch 466 gate circuit 465 is supplied.

The gate circuit 465 has output lines P and F, the circuit on output line F having a signal is high when the distributor vacuum is present and puts a high level output on line P, when the distributor selects negative pressure. A high signal on line F from gate circuit 465 shows indicates that the vehicle speed sampling circuit from the NO controller is not working. This signal is sent to the computer via a normally open Gate 467 and an OR gate 471 supplied so that the lamp 295 for the negative pressure advance ignition (Fig. 1-0 is activated. The output signal on line F from the gate circuit 465 is also the indicator light 470 for SSAD not in order forwarded. The test is completed and the T-piece is then removed from the engine vacuum line taken out.

If there is no pre-ignition manifold vacuum, then a high level output from gate circuit 465 on line P is fed to gate 476 to do so and a gate 468 is applied to open this gate. The high level signal on line P. the gate circuit 465 is also fed to the computer to (a) provide a speed change command signal is triggered via lamp 309 (Fig. 18) and (b) a voltage at connection 305 of the load index meter 166 (Fig. 18)

709807/030 1 _bath

which has a rate of change of approximately equivalent to half a mile per hour per second. This informs the driver that he is his Speed must change at a rate of about half a mile per second. This desired speed signal is continuously fed to terminal 305 of the load index meter until a speed of approximately 40 mph is reached or until the vacuum switch 466 produces an output on line F, which indicates that the lower pressure is present in the pre-ignition manifold, whichever condition occurs first.

If there is no negative pressure in the pre-ignition distributor, if the vehicle speed is the NO-upper speed limit (i.e. 40 mph) then it is assumed / that the NO controller is not operating;

the circuitry for making this decision will now be described. A subtracter unit 482 compares this measured speed signal with the NO device upper limit speed, which is stored in memory element 483 and generates an output on line F when the measured speed is the upper limit speed achieved. The output signal from the subtracter unit is sent to the not-in-order indicator light 470 via OR gates 471 and fed to the computer so that the lamp 295 is activated for the negative pressure advance ignition. The test is completed and the vacuum tee is removed.

If the negative pressure for the pre-ignition distributor is present before the NO upper speed limit is reached, then the vacuum switch 466 produces an output on line F which is sent to the computer via gate circuit 465

709807/0301

and gate 468 is applied, whereby the lamp 310 relating to holding the accelerator pedal on the load index meter 166 is activated. Now the computer delivers also sends a store command signal to a NO memory element 473 which stores the current NO signal. Because of the inherent instrument sampling delay becomes the value of the NO signal stored in element 473, represent engine operation for the case when pre-ignition manifold vacuum has not been applied. A timer 474, which provides a suitable time delay of 10 seconds, for example, is now provided by the computer also activated. The timer 474 delivers what is currently present at the end of the predetermined time delay NO signal to a divider 475, which is the currently valid

NO signal with a preset percentage NO

X X

Limit value, which is contained in the memory element 340, multiplied. Such a preset limit can be, for example, 57%. The present NO value

multiplied by the preset percentage limit value (contained in element 340) is saved with the NO signal from storage element 473 in the subtracter

Unit 476 compared. When the output signal from the Divider 475 is greater than the output signal from storage element 473, an output signal on line P becomes formed from the subtracting unit 476. When the output from divider 475 is less than the signal from element 473, then the subtracter provides an output on line F. A gate circuit 478 becomes opened by an actuation signal from a delay network 479 a short period of time after the instant at to which the timer 474 has passed the currently present NO signal to the divider 475. Gate circuit 478, in

709807/0301

In response to an output on line P from the subtracter, an indicator light 480 for J-iviert OK and activates an indicator light as a function of an output signal on line F from the subtracter 470 for bad through an OR gate 471. The okay or not okay signal is sent to the computer forwarded so that he activates lamp 295 concerning switching on the negative pressure advance ignition (Fig. 18) and thus the Test mechanic remind you to remove the T-piece from the engine vacuum line to remove.

Thus, a light 470 is used to indicate the SSAD failure may be activated when (1) there is no pre-ignition manifold vacuum when the vehicle is in the speed range which is prescribed by the signals from the storage elements 460 and 461 when (2) the value of NO with the pre-ignition manifold vacuum present does not exceed the value of NO by a predetermined amount of e.g. 50% in the absence of the pre-ignition distributor vacuum, or if (3) the pre-ignition distributor vacuum at an upper limit speed of e.g. 40 miles per hour as determined by the storage element 483 does not exist. The failure signals for the OR gate 471 are also sent to the computer for recording so that the special reason for failure for the SSAD control unit can be noted. The test mechanic will when the light 295 (Fig. 18) lights up, switch the engine vacuum system back to its original state and the Depress NO -On-operation switch 273 (Fig. 17) so that

the computer can proceed to the next test.

DIAGNOSTIC VALUE OF OXYGEN MEASUREMENTS

The oxygen content in the exhaust gas can indicate the presence of leaks

ORIGINAL BATHROOM 709807/0301

in the exhaust system of the vehicle reveal which

(1) a significant hazard to vehicle occupants and

(2) dilute the exhaust gas and therefore the measured concentration values of the exhaust gas during previous tests, especially when idling, where the entire exhaust gas' Volume is just low. Due to certain pump pulsations of the motor, which can mainly occur when idling, outside air can be drawn into the exhaust system itself through subtle leaks or from the end of the exhaust pipe connected to a small number of cylinders, with air then entering the sample for the Analyzer can be sucked in if the latter has not been inserted far enough into the exhaust pipe. Measurement of the oxygen content can also be useful in determining the function of the air induction pumps. Therefore the following tests can be carried out to confirm the exhaust gas measurements and, if necessary, provide information about Existing exhaust leaks and the mode of operation of air induction systems on the exhaust unit »

EVALUATION OF THE OXYGEN CONTENT FOR VEHICLES WITHOUT AIR INTAKE AND WITHOUT CATALYTIC POST-COMBUSTION

A circuit for estimating the O ₂ content in exhaust gases from vehicles that are not equipped with an air inlet pump or a catalytically operating converter (afterburner) is shown in FIG. If the exhaust selector switch 252 (Fig. 17) has been turned to the "ΝΟΝΕ position" and the catalyst switch 258 (Fig. 17) has been turned to the "NONE" position, then the computer compares the idle Mode only the O ^ values with the acceptable value by the device shown in FIG. The components shown in Fig. 26 and which correspond to the components from FIG. 21 have the same reference

709807/0301 originally inspected

If the acceptable O ₂ level is not exceeded, then the gate circuit 393 generates an activation signal for the indicator _{light 574 for O 2} OK, as well as for the light 496 via OR gate 493, which indicates that the exhaust system has no leak . The test is then completed. If the acceptable value of O _{2 is} exceeded, then an O ₂ fault light 575 is activated, excess oxygen also informs the test mechanic that the values for CO, HC and NO obtained in the idle mode should possibly be invalid, and in any case should not be readily accepted.

A failure signal from gate circuit 393 indicating that the oxygen content has exceeded the value acceptable for idling is sent to the computer so that the Light 300 for the pressure in the exhaust pipe (Fig. 18) is activated. The test mechanic will point out this instruction reduce the outlet cross-section of the exhaust pipe without that the sample tube for the analyzer is removed. If the exhaust pipe is under sufficient pressure, the test mechanic operates the switch 280 on his control panel (Fig. 17). Now the computer leaves the lamp 301 (Fig. 18) light up for pressurized exhaust pipe and opens gate 490 via a delay device 491 (Fig. 26) to account for the response time for the gas sample. The measured oxygen signal at under The pressurized exhaust pipe is then fed to the acceptable idle oxygen limit in a subtracter 492 compared. When the oxygen signal is under pressure standing gas pipe (1) exceeds the acceptable limit value for oxygen at idle, an output signal is generated generated on line F, or (2) remains below the acceptable limit, an output signal is generated on line

709807/0301

device P generated. A gate circuit 494 is activated via a delay network 495 and generated in FIG Depending on an output signal on line P from the subtracter 492, a failure indicator light 497 and transmits a signal to the computer, which has a lamp 302 for re-checking the exhaust system (Fig. 18) lights up and thus instructs the test mechanic to accommodate the emissions values at idle at moderate Check the pressurized exhaust pipe again. The test mechanic then operates the re-test switch 282 on his test desk (Fig..17) and the computer compares depending on it the measured values of CO, HC and NO with the acceptable limit values by means of the circuit from FIG. 21.

Because of the usually very high mass throughput through the exhaust system at high and low travel speeds, there must already be a considerable break in the exhaust system so that the results of these tests with the modems mentioned are falsified and thus invalid. If it is desirable, however, even this single modem can be carried out again, the exhaust system under Dru: k is set.

The gate circuit 494 outputs in response to an output signal on line F from the subtracter 492 a high level signal on two AND gates 499 and 500 .; An HC idle failure storage element 501 becomes sampled at this point and its output is given directly to AND gate 499, and the inverted Output is given to AND gate 500 via an inverter 502. A high level output from the element 501 indicates that the acceptable limit for HC in the idle mode has become over very much and an output of low from element 501 indicates that the

709807/0301

acceptable value has not been exceeded.

AND gate 499 and OR gate 493 activate an indicator light 496 for exhaust leak not present / when (a) the O ₂ signal remains above the idle limit with the exhaust pipe under pressure and (b) the HC signal exceeded the acceptable limit at idle (with no exhaust pipe under pressure). AND gate 500 transmits a signal to the computer to execute the repeat test / sample light 498 when

(a) the 0 ~ signal remains above the idle limit and

(b) the HC signal did not exceed the acceptable limit when idling. In the latter case, the analyzing-sampling chain must be repaired to remove the air leak and the test repeated.

OXYGEN TEST AT IDLE FOR VEHICLES WITH AIR SUPPLIED IN THE EXHAUST SYSTEM AND NON-CATALYTIC POST-COMBUSTION ,

Figures 27 and 27A show a circuit for estimating the oxygen content in an exhaust gas stream from vehicles those with an air supply system for the exhaust system, however are equipped without a catalytic afterburner. The circuit of FIGS. 27 and 27a provides information concerning the functionality of the vehicle air supply system and concerning the condition of the vehicle exhaust system.

The amounts of oxygen and CO that are normally present in the exhaust gas of an internal combustion engine depend on whether the machine is working poorer or richer than the stiochiometric ratio. The amount of oxygen will larger and the amount of CO will be smaller when the machine

70 980 77 0 3 Ö 1

works at a lower than stiochiometric ratio. For this reason, the CO signal must start with a predetermined limit of, for example, 1% are compared to determine the operating point of the engine before the amount of oxygen is determined to ensure proper functioning diagnose the air supply system and the condition of the exhaust system.

27, the stabilized CO signal from the Gate 364 in the idle mode in a subtracter 504 is compared to the predetermined 1% CO limit value from item 503. If the measured value of CO is above the The subtraction unit delivers the 1% CO limit 504 provides an output signal on line A, and when the measured value of CO is below the 1% CO limit, provides the subtracter 504 has an output on line B. An output on line B from the subtracter 504 since & indicates that the engine is at leaner than stiochiometric Ratio works, a gate 505 is fed to its opening, so that the stabilized oxygen signal a subtracting unit 506 and an oxygen storage element 506a can be supplied. The subtracting unit 506 compares the oxygen signal with a preset one percentage limit of e.g. 4%, which is stored in element 507, and provides an output signal on lines A and B if the measured oxygen signal is above or below the 4% limit. A gate circuit 508 activates after opening by delay device 509 an indicator light 510 relating to the failure of the air pumping system via OR gate 509a, if the measured oxygen signal is below the 4% limit, and informs let the test mechanic know that the air supply is not working properly.

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In response to an output signal on line A from subtracting unit 506, a gate circuit delivers 508 a signal to the computer, so that lamp 300 (Fig. 18) for pressurized exhaust pipe will be activated because the measured oxygen signal is above the 4% limit. Depending on the lighting up of the last-mentioned lamp, the test mechanic will determine the outlet area of the exhaust pipe without taking away the analyzer sample and then press the switch 280 (Fig.17) to use the Computer notify that the exhaust pipe has been pressurized. Depending on this signal transmits the computer sends an exhaust pipe acknowledge signal to a delay network 512 which in turn is a gate 511 opens after a suitable time delay, which takes into account the response time of the gas analyzer. Gate 511 transmits the stabilized oxygen signal to a dual subtracter 513. The dual subtracter 513 compares the measured oxygen signal with the oxygen signal plus or stored in element 507 minus a suitable percentage, e.g. 1/2%, to determine whether the oxygen signal has been increasing the pressurization of the exhaust pipe has changed. The oxygen signal stored in element 507 is compared with the preset percentage change limit of e.g. 1/2%, stored in element 514, with the help of the divider 515 multiplied. The preset percentage of the stored oxygen signal, i.e. for example 1/2%, becomes the oxygen signal stored in adder 516 and subtracted from the oxygen signal in magnitude subtracter 517. Thus represent the inputs to the subtracter from components 516 and 517 represents the stored oxygen signal plus and minus 1/2%.

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The dual subtracter 513 provides an output signal Line P, if the measured value of the oxygen with the exhaust pipe is under pressure is the original value of oxygen has not exceeded by 1/2%. The subtracter 513 provides an output on line F, when the oxygen signal with the exhaust pipe under pressure has changed by more than 1/2%. A gate circuit 518, when actuated, cycles through a delay network 519 the outputs from the dual subtracter 513 and activates a light 524 to indicate an in-order air intake system via OR gates 519A as a function of an output signal on line P. from the dual subtracter 513.

The gate circuit 518 opens a gate 520 in response to an output signal on line F from the subtracting unit 513, indicating that the oxygen signal reverse than the preset amount has changed by 1/2%. After opening, the gate 520 transmits the measured oxygen signal to a subtraction unit 521, which shows the measured oxygen signal at below Compare the pressurized exhaust pipe with the 4% limit value signal for oxygen from storage element 507. The subtracter 521 provides an output signal on line P or on line F if the measured oxygen value is below Pressurized exhaust pipe is below or above the 4% limit. A gate circuit 522 samples when triggered by the delay unit 523, the output lines from the subtracter 521 and activates a Light 524 for OK air intake system via OR gate 519A and a lamp 497 for the failure of the exhaust system via OR gate 525 as a function of an output on line P from the subtracter 521. The gate circuit 522 activates in response to

7098Ö7 / 03Ö1

an output on line F from the subtracter 521 the lamp 497 for the failure of the exhaust system via OR gate 525 and lamp 510 for the failure of the Air intake system via OR gate 509A.

If the machine is richer (e.g. richer) than the stiochiometric ratio (CO signal greater than 1%) With element 503 operating, the circuit of Fig. 27A is used to estimate the operation of the air induction system of the vehicle and the exhaust system. The circuit details of Fig. 27A correspond to the circuit components from Fig. 27 with the exception of the percent oxygen limit in element 507 and therefore have the same reference numerals, each provided with '. . The output signal on line A from the subtracting unit 504 (Fig. 27), the indicates that the engine is working richer than the stiochiometric ratio, a gate 505 ' and opens this, thereby putting the circuit of Fig. 27A into operation. The circuit of Fig. 27A operates but in the same way as that of Fig. 27 except that the percentages stored in element 507 ' Oxygen limit values are lower, e.g. 3%. If the measured oxygen signal falls below the 3% limit, the lamp 510 will indicate the failure of the air injection activated. If the measured oxygen signal exceeds the 3% limit, the computer instructs the test mechanic to pressurize the exhaust pipe as explained above. The measured oxygen signal when the The exhaust pipe is compared to the stored oxygen signal when the exhaust pipe is not under pressure to 'determine whether the oxygen level is within the preset Limit of for example 1/2% has changed or not. If the oxygen signal doesn't have this Has changed beyond limits, the lights 524 and are activated and indicate that the air pump is working and that

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263388Q

the exhaust system does not leak. When the measured oxygen signal has dropped below the preset half percent limit when the exhaust pipe is under pressure, but still remains above the 3% limit (storage element 507 '), lights 525 and 497 will come on, indicating that the air pump is working but the exhaust system is working licks. If the measured oxygen signal is above the preset Limit has dropped and is below the 3% limit, lights 497 and 510 will come on to indicate that the air pump is not working and that the exhaust system is leaking.

When the computer activates the Exhaust Leak Light 497, he also activates the lamp 302 for test repetition / exhaust (Pig.18) and thus instructs the test mechanic to use the Test values for CO, HC and NO again at idle, whereby

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moderate pressure is applied to the exhaust pipe. The test mechanic then operates the test retry switch 282 (FIg * 17) and the measured values of CO, HC and NO are compared with the acceptable values via the circuit from Fig. compared.

The circuit of FIGS. 27 and 27A can also be used to test for exhaust gas leaks in vehicles that do not have additional air introduction into the exhaust system, though only the oxygen limit values can be selected appropriately.

TEST FOR VEHICLES WITH CATALYTIC AFTERBURNERS

When a vehicle is equipped with a catalytic afterburner the selector switch 258 of FIG. 17 is rotated to the HC / CO position. The NO / HC / CO switch position is pre-

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seen, in the event that vehicles should also be equipped with catalysts for the reduction of NO in the future.

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709807 / 03Ö1

-ro-

263388G

Catalytic afterburners or catalytic ones in general Convertors are supposed to control the exhaust gas emissions of the engine itself before the exhaust reaches the exhaust pipe outlet. The extraction and analysis of the exhaust gas is at the exhaust pipe capable of determining the emissions load from the exhaust pipe while the engine is idling and under Such a load runs, such as slow speed, high speed and possibly also full throttle correspond. These values are routinely obtained during the basic test using the circuit of FIG. 21 and serve to obtain a statement about the vehicle as an admissible or impermissible polluter at the test time. There however, an active catalyst determines the content of CO and HC the machine itself, the values for these gases, provided they are on the downstream side of the catalytic converter Exhaust pipe are obtained are not related to the CO and HC gas quantities emitted by the engine. Therefore the essential contribution to engine diagnosis is rather obscured or obscured by an active catalytic converter. the The meaning of this circumstance is as follows:

1. A vehicle that goes through a test in which the sample was taken from the exhaust pipe may have incorrect settings and / or have malfunctions which (a) increase fuel consumption and / or (b) the now active catalytic converter with abnormal high emissions can overload and thus reduce the life of the catalytic converter, with unsatisfactory Emissions into the environment result in a disproportionately short period of use.

2. A vehicle that passes an emissions test with exhaust pipe sampling unsuccessful can either be afflicted with a fault in the catalytic converter or in the machine or in both. The lack of a positive diagnosis the cause or causes can (a) lead to a replacement of the catalytic converters in the case of an excessively emitting Machine reduce the service life of the replacement catalytic converter

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will, although an emissions retest for confirmation the repair will find the exhaust pipe emissions acceptable or acceptable; (b) the lack of knowledge The cause of engine failure can and will result in inadequate or excessive repair of the engine therefore not be cost effective in one case or the other,

It is therefore expedient to have a lockable system between the engine and the afterburner or catalytic system Provide an opening that allows the emissions checked from both the engine and the exhaust pipe and can be examined. This opening is referred to hereinafter as the engine exhaust gas test opening.

TESTS FOR VEHICLES WITH CATALYTIC AFTERBURNERS AND ENGINE AEGAS TEST OPENINGS

Preferably, during the CO and HC tests, the exhaust gas is both taken from the exhaust pipe as well as from the engine exhaust gas test opening instead of just from the exhaust pipe. Since relatively few Vehicles equipped with catalytic afterburners have so far been equipped with these engine exhaust gas test openings, the apparatus of the present invention requires that the exhaust gas sample be obtained from two locations by performing the basic test (high speed, low speed, idle) is repeated and the same gas analysis sequence is used and the two sets of data are compared to determine the effectiveness of the catalyst. A first Test is carried out while either out of the exhaust pipe. or is taken from the engine exhaust gas test port, and it becomes a second test is carried out with exhaust gas taken from the point not used in the first test. While When running a sample at the engine exhaust test port, the acceptable limits for all gases are those that are apply to an engine without a catalytic afterburner, and therefore the vintage selector 250 (Fig. 17) can accordingly,

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for example for the model years 1973 to 1974 (see Table E).

The okay-failure gas signals generated during sampling obtained from the exhaust pipe are used to form a statement as to whether the vehicle is acceptable or has unacceptable emissions. The okay / Failure gas signals, which are obtained from the engine exhaust gas test opening when a sample is taken, provide information on the condition of the engine and the nature of the defect as well as on vehicles without catalytic afterburning according to the above Description. The difference in HC / CO values between the first and second test determines the effectiveness of the HC / CO catalyst. If vehicles are equipped with catalytic converters to reduce NO in the future, the difference will be the NO values between the first and the second test in a similar way a conclusion about the effectiveness of the Enable NO catalyst.

TEST FOR VEHICLES WITH CATALYTIC POST-COMBUSTION AND WITHOUT ENGINE EXHAUST TEST

The selector switch 258 from Fig. 17 must be in the position HC / CO stand. Although it does not address the disadvantages of maintaining the original engine emissions can be used to operate the HC / CO part of the afterburner can be tested largely with the circuit of FIG. To test the operation of the HC / CO part of the catalytic After the basic tests have been completed, the test mechanic short-circuits one of the engine cylinders and the afterburner actuates the short-circuited cylinder switch 283 (Fig. 17). The vehicle is then in at least one of the mentioned power ranges (i.e. high speed or low speed Speed), optionally also in all modes

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operated »The HC signal without an arbitrary short circuit during the respective test mode ¹ (eg high speed) had previously been stored in the memory element 530. The stored HC signal is multiplied in a divider 531 by a preselected HC% limit from the storage element 532, for example 150%.

The stabilized HC signal from gate 365 is combined with the output of divider 531 in a subtracter 533 compared. If the measured value of the HC with a short-circuited cylinder is smaller than the Output of divider 531, indicating that the HC content has not increased by more than the predetermined percentage has decreased the HC value that was previously stored, then the subtracter provides an output signal Line P. If the HC value exceeds the value of the output of the divider 531 with a short-circuited cylinder, the subtracter supplies an output signal on the line P, which indicates that the catalytic afterburner is operating effectively. A gate circuit 534 activates when opened a delay network 535 in response to an output on line P or P from subtracter 533 a light 580 to indicate "OK", or a failure indicator light 581

Upon completion of the tests dictated by setting the controls of Figure 17, the computer will display the Test mechanics indicate that the programmed tests, decisions, and data assumptions are complete by pressing the test completion light 303 (Fig. 18) lights up. The signal for the lamp 303-allows the computer to work on a signal by actuating the switch 318 (Fig. 19) through the Test Mechanic was generated, which raises the lift. Thus, a lift raise signal on line 156 is only then applied occur when the computer has indicated that the entire

7 0-9 807/0301

Program is complete. This prevents the test mechanic takes down the vehicle by the dynamometer _f is finished before the test program. If the dynamometer device is a mechanical device that allows the elevator to be raised only by supervisors, then the vehicle can be removed prior to the completion of the test program in the event that this should prove necessary.

RESULTS DISPLAY BOARD

A result display for the control system is shown in Figure 29, in which the test modes (i.e., high speed, low speed etc.) are arranged in columns and the measured gas values in rows. The NO control unit operation test and the exhaust system test are not relevant to all test modes, as discussed above. The lights to indicate that the measured values of CO Acceptable or unacceptable are indicated by 540 to 547. The indicator lights 550 to 557 are for information the test mechanic whether the measured values of HC are acceptable. The indicator lights 560 to 567 and 570 to 577 serve to inform the test mechanic regarding the condition or failure for NO and oxygen. The mode of operation of the catalytic

Afterburner for HC / CO is indicated by lights 580 bis 587 is displayed for OK and failure. The operating mode of the NO control unit TSAD is indicated by lights 418 and 420

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indicated what was explained above in connection with FIG. The mode of operation of the NO control unit SAD is indicated by lights 436, 438 (Fig. 23). The mode of operation of the NO control unit SSAD is indicated by the lights

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480 and 470 (Fig. 25). The mode of operation of the NO control unit for vehicles with EGR is indicated by lights

450 and 451 (Fig. 24). The mode of operation for Air injection systems into the exhaust system for vehicles

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is made visible by lights 524 and 51O (Fig. 27). Lights 496 or 497 show leaks in the exhaust system (Fig. 36) at.

DIAGNOSTICS TABLE FOR AUTOMATIC DISPLAY OF ENGINE FAULTS AND REPAIR INSTRUCTIONS

30 shows a diagnosis matrix which is used as element 200 in Fig. 14 is shown showing a diagnosis of engine failure etc. supplies by the CO and HC failure signals which decrease during the high speed Speed and idle tests have been recorded. A high output from the storage elements represents a failure signal and a low level output represents a pass signal. On the basis of the particular failure image, the circuit of FIG. 30 selects the appropriate report form or the report forms, which are then designated by the computer, and printed out so that it can then be given to the vehicle owner it becomes possible to have the vehicle repaired or readjusted with minimal effort, of course.

The CO and HG failure signals are recorded by the computer in memory elements 600, 601, 602, 603, 604 and 605 as shown for the high speed mode, the low speed mode and the idle mode. An AND gate 620 operates the selector 611 in response to a CO fail signal in the idle mode and a CO pass signal in the high speed mode via inverter 626 to designate or print report form No. 1. An OR gate 621 and an AND gate 621A operates a selector 612 which designates or prints out a report form No. 2 in response to a CO failure signal in the high or low speed mode, and a CO pass signal in idle mode. Mode over

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Inverter 628. An AND gate 622 operates a selector 613 which generates report form No. 3 in response to a CO failure signal in both the high speed mode and the idle mode. An AND gate 623 operates a selector 614 which generates report form No. 4 in response to an HC failure signal in idle mode and a CO pass signal in high speed mode via inverter 627. An OR gate 624 and an AND gate 624A actuates a selector 615 which outputs report form No. 5 in dependence from an HC failure signal in high or low speed mode and an HC pass signal in idle mode printed out via inverter 629. An AND gate 625 operates a selector 616 which is report form # 6 in dependency of an HC failure signal in both the high speed mode and the idle mode.

Report Forms 1-6 are listed below. Report Form No. 1

idle Slow Fast CO failure Passed /
failure Passed HC Usual root cause

1. Gross error in the air / fuel mixture setting

in the carburetor at idle.
2. · Seldom high CO content when idling, sometimes even at slow speeds, as can be seen from the second example.

709807/0301

SURVEY

1. Inspection of the PCV system for cleanliness and correctness Operation. A fault in the PCV system can lead to faulty idling.

2. Basic idle setting of the motor on the interrupter, with regard to ignition timing, idling speed and air / Fuel mixture.

CAUTION

After performing the basic engine idle setting, at least Accelerate 3 χ and let it return to idle. Observation of the stability and compliance with the idle setting.

3. In rare cases where idle settings are a result large amounts of paint or other fuel deposits in the idle channels of the carburetor can be carried out exactly, it may be necessary to use the. Replace or repair carburetor.

Report Form No. 2

Slow Fast Failure and / or failure

The most common cause is a failure in the main carburetor system. A loose idle setting cannot eliminate this problem.

Elimination

1. Check the carburetor air filter for abnormal contamination.

idle CO Passed HC Usual root cause

709807 / 03Ö1

2. Check the starter cable for jamming in the partially closed position.

3. If 1. and 2. are OK, acceptance of the carburetor and replacement or repair according to the manufacturer's instructions.

4. Always basic idle settings of the interrupter distance and time, the idle speed and of the air / fuel mixture.

Note: If the carburetor is to be reassembled, the following must be checked:

1. Check that the enrichment valve is working properly.

2. Check all vacuum channels of the enrichment valve for acidity and opening.

3. Note loss of main jet (s) and / or enrichment valve.

4. Check the seat of the main jet or the seat of the seal.

5. Check the nozzle and / or plunger for wear. Minor wear and tear can be significantly higher Cause CO emissions.

6. Check the flow for abnormal damage or Leaks.

7. Check for damaged or loose overflow valve.

8. Check the nozzle group and group gasket for damage or breaks.

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9. Thoroughly inspect the entire carburetor housing for cracks or cracks, especially that all plugs are firmly and correctly seated.

Report form No. 3

CO idle Slow or Fast HC failure Passed failure failure Common cause

A combination of a fault in the main carburetor system and a poorly adjusted air / fuel mixture in the Idle.

Elimination

1. See Form No. 2. The main system error should obviously to be fixed first.

2. The idle CO content is set after the basic settings have been made be corrected.

3. Always carry out the basic settings for idling

the ignition interval and timing, the idling speed and the air / fuel ratio.

Report Form No. 4

Idle Slow Fast

HC Failure Pass or Pass

Failure.

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Common causes

1. Vacuum leaks in the intake system, causing a too result in a lean mixture and therefore misfire in some cylinders.

2. Idle circuits in carburetors for cylinders 2 and 4 in highly unbalanced or too lean.

3. Intermittent misfire is possible but not likely.

4. Ignition point set roughly too early.

5. Moderate compression leak through one or more exhaust valves.

6. Extraordinarily high CO levels when idling can be moderate cause high HC content when idling (first set the idle CO content and then determine whether further Repairs are necessary).

Elimination

1. Note the idle CO content on the report card and note that the idle is not set too lean (less than 1.0% CO).

2. Misfire at idle and not at higher RPM under load is uncommon; the simplicity of a However, oscilloscope exam suggests this exam to be the next.

709807/0301

3. Investigate whether the basic ignition point is not roughly too early.

4. Check for uniform settings with 2 or 4-cylinder carburetors.

5. Check for vacuum leaks in the inlet line.

6. If the above steps do not reveal the source of the failure, perform a cylinder compression test by. Burned exhaust valves can be up to four times the normal HC value when idling generate with only a relatively small increase in the higher speeds.

7. Always carry out the basic idle settings of the ignition interval and timing of the idle speed and the air / fuel ratio.

Report Form No. 5

Slow Fast Failure and / or failure

Misfire under higher compression pressures under load due to failure of a component in the ignition system.

Elimination

1. Perhaps the most common problem is a faulty one Spark plug; however, this conclusion should not be drawn without careful consideration.

idle CO HC Passed Usual causes

709807/0301

2. Check the ignition system with an oscilloscope and associated instruments. If the oscilloscope doesn't clearly shows a faulty spark plug, examine the following:

a) Faulty ignition cables.

b) peak discharge.

c) Spark discharge due to broken or charred caps or rotor.

d) If the preceding steps do not reveal the source of the error, the problem may arise circled in the following manner, with a The most accurate diagnosis possible should be run until the problem is found. The individual steps are listed below in order of the frequency of the most common error:

1. Spark plugs.

2. Ignition wire and coil-wire resistance.

3. Extraordinary peak discharge.

4. Distributor cap or shaft shows cracks or coking or char.

5. Precipitation inside the distributor cap or on the cables.

6. Extremely incorrect interrupter angle - gap.

7. Too low output voltage of the coil.

8. Insufficient primary voltage for the coil.

9. Loose wire connections on the distributor ground plate or on the coil and wire connections.

3. Always carry out the basic idle settings of the ignition interval and time, the idle speed and the air / fuel mixture.

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Report form No. 6

idle Slow or Fast CO HC failure Passed failure failure usual causes

The most likely cause is a misfire as per report card # 5.

Elimination

1. Compare report card No. 5 and carry out the repair accordingly.

2. In rare cases it may be necessary to refer to report card no. 4 if the repair according to report card no. 5 does not bring the hydrocarbon content within reasonable limits when idling.

3. Always carry out the basic idle settings of the ignition interval and time, the idle speed and the air / fuel ratio.

The report forms presented above are based on data derived from many vehicles that failed the CO and HC tests during various test modes and then analyzed to determine where the error occurred and what the best procedure for the necessary repairs and / or adjustments is. Additional report forms can be used to provide more complete diagnosis and repair instructions for excessive NO and oxygen levels as more data becomes available.

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DESCRIPTION OF A GAS STABILIZING DEVICE FOR USE IN THE CIRCUIT ACCORDING TO FIG. 21

Figures 31 and 32 show one type of gas stabilizer circuit for use in the circuit that. is shown in FIG. This circuit is from the analog Type and includes a pair of operational amplifiers 632 and 634. An analog voltage that the measured speed is supplied to an input of each amplifier 632 and 634. Analog voltages that the top and lower speed limits are assigned to the other inputs of amplifiers 633 and 634 as shown fed. Each amplifier provides a low level output signal when the measured speed signal falls between the upper and lower limit speed signals and an amplifier supplies one high-level output signal when the measured speed signal is above or below the limit values. the Outputs of the amplifiers 632 and 634 are fed through a NOR gate 635 to a timer circuit which has a Operational amplifier 636, a capacitor 637, a pair of resistors and a diode. If any Input to NOR gate 635 is low, the gate provides a high output indicating the charging of the capacitor 637 lets begin. One input to the amplifier is fed to capacitor 637 and the other input 638 is connected to a suitable reference voltage.

The amplifier 636 provides a low output signal until the input signal supplied by the capacitor 637 is equal to the reference voltage, and then the output of the amplifier goes up. The time delay

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between the appearance of a high level signal at the output of NOR gate 635 and a high level signal at the output of the amplifier 636 is determined by the magnitude of the reference voltage which is applied to the connection 638. The time delay is thus adjustable and can be set to a suitable period of time of, for example, 2 seconds can be adjusted, thereby ensuring that the vehicle speed has stabilized, i.e. has become constant is. The high output from amplifier 636 is considered a speed trip signal and is used by an inverter 639 is supplied to an input 640 of a flip-flop 641.

The gas stabilization circuit for CO, the rest of the Circuit components of Fig. 31 will now be described. This circuit transmits the measured CO signal to a comparator circuit, which the measured CO signal compares to an acceptable limit if one of the following three conditions is met:

(1) The measured CO signal has at least momentarily finished changing within a specified rate of change limits and has a predetermined period of time, e.g.

10 seconds has passed.

(2) The measured CO signal stopped fluctuations within a predetermined rate of change limits over a predetermined time interval of, for example, 3 seconds.

(3) the measured CO signal has fallen below the acceptable limit with a predetermined high rate of change and stayed at the given rate of change over a short, preset period of time, e.g. 500 Milliseconds.

Condition (1) concerns those cases in which the gas signal continues to fluctuate and delivers a gas signal

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this over a relatively long period of time of e.g. 10 seconds is averaged to ensure that an average is used in the comparison. Condition (2) concerns cases in which the gas signal remains stable within a relatively narrow range of change limits that allow that the gas signal can be averaged over a short period of time, for example 3 seconds. The condition (3) concerns cases where the gas signal decreases at a great rate and below the acceptable one The value drops and thus creates a guarantee that the gas signal will remain below the limit value.

The point of these three conditions is to reduce the total test time to a minimum, while still being valid Data are to be made available for the intended purpose. For example, when in use Vehicles should only be tested to see whether they are OK or have failed the test the three conditions are used. However, if the measured gas values to determine a statistical estimate the pollutant emission are to be collected, only condition (1) should be used.

To determine whether the gas signal has stopped fluctuating within given limits, the measured CO signal fed in analog form to an input of an amplifier 644 via a capacitor 643. The output signal from the Amplifier 644 is an analog signal that represents the rate of change of the measured CO signal. The rate of change or the differentiated CO signal from amplifier 644 becomes an input of a pair of operational amplifiers 647 and 648 as shown. The other input of amplifier 647 a reference voltage for the upper change

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speed and the other input of amplifier 648 becomes a reference voltage for the lower rate of change fed. The amplifier 647 provides a low output when the reference voltage is more positive is than the differentiated CO signal. The amplifier 648 provides a low output signal when that is applied to it Reference voltage is more negative than the differentiated CO signal.

The low speed trip signal from the inverter 639 is fed to an input of a NOR gate 650. The amplifiers 647 and 648 also output low signals the NOR gate 650 when the differentiated CO signal is between the upper rate of change limit and the lower Rate of change limit remains. The three low inputs to NOR gate 650 provide a high output for the other input of terminal 651 of flip-flop 641. This high signal on terminal 651 triggers that Flip-flop 641 which provides a high signal at its output terminal 652.

The high output from flip-flop 641 is fed to a first gas timing circuit which is an operational amplifier 654 and a capacitor 655 and the resistors and diode shown. A reference voltage becomes fed to terminal 656 of amplifier 654 and the magnitude of this reference voltage determines the time delay between a high output signal at output terminal 652 and at output terminal 657 of amplifier 654. This time delay ' can take 10 seconds, for example. A high output from amplifier 654 closes an FET switch 658. The switch 658 connects, when it is closed, the measured CO signal on line 230 and a signal

7 0 9807/0301

Middle circuit 659 in series with an input of an operational amplifier 660. The other input of the operational amplifier 660 is applied to an analog signal which the represents an acceptable value for CO for the respective test mode. The amplifier 660 provides a high output on output line 661 when the detected CO signal is below the acceptable limit and produces a low output on output line 661 when the the mean value of CO exceeds the acceptable limit. The output signal of the amplifier 660 is fed through a gate circuit 662 lights P and F as already discussed, which indicate the pass and failure of the test, and inform the test engineer in detail whether the measured CO signal remained below or exceeded the acceptable CO limit.

The timer circuit includes an amplifier 654 which thus feeds the measured CO signal through the middle circuit 659 (= averaging circuit) connects to the comparator, namely a predetermined period of time after the measured CO signal ended the fluctuation at least momentarily within a rate of change that by the upper change-speed limit signal and the lower change-speed limit signal which are fed to amplifiers 647 and 648 is determined. If the measured CO signal is in the range between the upper rate of change limit value and the lower rate of change limit value momentarily falls into it and then exceeds one or the other of the stated limits, NOR gate 650 will output a low deliver. This low output signal will not change the state of flip-flop 641 and thus enable that the switch 658 after the time delay of example

7 0 9 8 07/0301

closes for 10 seconds, which is determined by the size of the reference voltage at terminal 656.

The circuit that supplies a stabilized gas signal under condition (2) will now be explained. A high one Signal at terminal 651 resulting from the measured CO signal being in the rate of change range limit drops, starts charging a capacitor 671, which a second gas timer circuit with amplifier 670 forms. The time delay of the second gas timer circuit of e.g. 3 seconds is determined by the Determines the size of the reference voltage that is applied to terminal 672. When the output of NOR gate 650 is above the The amount of time that is required to charge the capacitor 671 to the reference voltage at the terminal 672 remains high, then the amplifier 670 will provide a high output and the FET switch 675 (= PeId effect transistor switch) conclude. Closing switch 675 creates a series connection of the measured CO signal with a second Signal means circuit 676 as well as having an input of an amplifier 660 as shown in the drawing. Thus, if the measured CO signal remains within the range, which is determined by the upper limit value signal and the lower limit value signal for the rate of change, namely over the period of time that is required for the second gas timer circuit of e.g. 3 seconds, the CO signal is then assumed to be stabilized, which is then compared to the acceptable CO limit. When the measured CO signal exceeds and then into the rate of change range during the time delay the. second gas timer circuit falls, then that circuit is reset.

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The circuit that supplies the stabilized gas signal in accordance with condition (3) will now be described. These The circuit comprises an operational amplifier 680 which receives as an input the differentiated CO signal and compares this differentiated signal with a reference voltage applied to input 681. The amplitude of the The reference voltage at the input terminal 681 determines the magnitude of the rate of change of the CO signal, which is required to get a high output from the op amp 684 to deliver. Operational amplifier 684 compares the measured CO signal to the acceptable CO limit and generates a high output signal when the measured CO signal is below the threshold signal for an appropriate amount CO level has fallen. Thus, AND gate 682 produces a high signal at its output when the three conditions are met, namely (a) the measured value of CO is much below the limit for an acceptable one CO content, (b) the measured speed remained within the range defined by the upper and lower speed limits is given, and (c) the measured value of CO- falls at a great rate due to the magnitude the reference voltage applied to terminal 681 is determined.

The output of AND gate 682 becomes a third gas timer circuit which includes an amplifier 690 and a capacitor 691. The amplitude of the reference voltage, which is applied to terminal 692 of amplifier 690 determines the time delay between occurrences a high output from AND gate 682 and a high output at the output of the amplifier 690. This time delay can be, for example, 1/2 to 1 second. The high output signal from the amplifier 690 closes a third FET switch 695 which feeds the measured CO signal to an input of amplifier 660 so that

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a comparison is made possible between the measured CO content and the limit value for an appropriate CO content.

Recall that one or more of the gas timer circuits can be used as required * If the actual values of the gas are recorded the third gas timer circuit need not be used appropriately.

The output from amplifier 660 becomes a gate circuit 662 is supplied to the lights to indicate the pass or failure of the test. the Gate circuit 662 is activated a short period later after the stabilized throttle signal is applied to comparator amplifier 660 to ensure that the amplifier actually performed the comparison.

Gate circuit 662 receives an actuation signal Line 663 from an amplifier 700 which forms part of a timer circuit with capacitor 702. The size a reference voltage applied to terminal 703 determines the time delay of the timer circuit As already mentioned.

An AND gate 704 produces a high output which is the time delay for the circuit to the amplifier 700 as a function of the speed trip signal (high output from amplifier 636) and a high output signal from one of the amplifiers 654, 670 and 690 through a. OR gate 705 triggers. Thus, the gate circuit becomes 662 opens a short period of time after the instant after the speed trip signal is generated

709807/0301

and the measured CO signal stabilizes as mentioned Has.

The circuit according to FIG. 32 works in the same way as the circuit just described and supplies a stabilized HC signal "so that the corresponding components have been given the same reference numerals, but with an apostrophe" The one under schise. swischen the two circuits in order dsm _s fact that aas ϋΙϊΒ gate having a third input 704 ° _y is from the output of the amplifier 700 (FIG. 31} removed via line 663 wurdeο Thus -is the gate circuit S62 in the circuit of Figc ^ 32 only opened wsrm both the measured CO signal and the measured signal HG have stabilized the circuit of FI9% 32 can also dasu äienen stabilized _HO,.? - and O ^ signal su Ii ΐ learning.

The mode of operation of the gas stabilizer from Fig. 31 shows graphically Flg. 33. The ordinate represents the amplitude here the measured gas sign is and Äis abssisse the side The curve 710 represents the gas signal = measuring sn The line 7 "? 2 represents d.,. A acceptable value for this Gsssigiai and lines 714 and 71S represent the upper and lower limits represent the rate of change whose js ^ belong Sicuale the amplifiers 647 ur ^. 648 supplied -'srdsn = The angle between these straight lines is rait £ issaishnst = Line 714 represents the minimum yaw rate for the measurement at high health (item 3), which is determined by the size of the reference voltage at terminal 681 is determined. The angle between the straight line 714 and the vertical 718 is denoted by S.

The measured gas signal is deemed to be stabilized for the purpose of subsequent comparison with the acceptable limit value considered when Ca) the gas signal decreases at a rate within the angle cβ, below the acceptable one

7098 07/0301

Gas limit 712 drops and continues at the acceptable rate of change drops over the period of time determined by the third gas timer circuit (Condition 3) is determined, or (3b) if the gas signal does not match decreased at a speed determined by the angle δ, but to the angle θ during the period falls by the second timer circuit (condition No. 2) is determined, or if (c) the gas signal momentarily falls within the angle θ and the first timer circuit expires, ie. for example 10 seconds have elapsed (condition 1). The signal averaging circuits 656 and 676 are equipped with different time constants (e.g. 10 seconds and 3 seconds) to ensure that the measured signal is a time weighted average of the actual signal. On request you can convert the analog signals from switches 658, 675 and 695 (Fig. 31) to digital signals by using appropriate ones Analog / digital converters implemented and subtractors 380, .etc. from Fig. 21 for a digital comparison of the measured Ga .. \ values with the acceptable limit values as discussed above.

The foregoing has provided an apparatus for manually or automatically assessing exhaust emissions from vehicles in the case of mandatory tests designed to identify damage to the engine and / or the exhaust system. The various digital Subtractors, dual subtractors, gate circuits, the 21-28, for example, may be of the type shown in the above-referenced application are explained. It goes without saying that the invention is not restricted to the individual provisions of the test modes explained above limited, further tests can be added or other tests omitted without thereby departing from the spirit of the invention is deviated.

709807/03 0.1

-1 Cl? -

Overall, a modal test method and a device suitable for its execution have been described, which are used by vehicle manufacturers, repair shops, diagnostic centers and the like for fast, accurate and repeatable measurement of the main air pollutants, ie carbon monoxide (CO) and Hydrocarbons (HC) from engine exhaust gases can be used. The quantitative measurement of nitrogen oxides (NO) and the oxygen content (O ₉ ) can also be measured on request. While oxygen is not an air pollutant, the measurement of a concentration in the exhaust gas is of value for obtaining reliable diagnostic information. The engines are operated in prescribed test modes (usually three, namely high speed, low speed and idling), in which any damage that is present is most likely to reveal itself to the exhaust gas composition. CO and HC (NO and Oxygen Desired) determinations are made in each test mode and recorded on a report card. The measured test values of the air pollutants are compared either automatically or manually with the prescribed permissible values in each test mode. For example, the measured values can be recorded on a report card that already contains the permitted values. An excessively high value of the measured air pollutant in one of the prescribed test modes indicates damage to the engine and justifies its rejection. A readjustment or repair to remedy the damage is indicated by a diagnosis card with a recommendation for the repair, with the diagnosis card also specifying the reason for rejection, which can be taken from the report card, and additional information about the probable errors and instructions for their removal.

7098 07/0301

A filled brake device enables the machine to be automatically loaded with a repeatable, predetermined load at a prescribed test speed in each mode, according to a substantially cubic power / speed curve. An engine assessment test can be carried out using three commonly prescribed test modes in conjunction with a fourth mode in which the engine is running at full throttle. The latter test requires a power absorption device that allows the load on the engine to vary at any desired speed. More sophisticated additional devices enable an automatic display as well as a printout of the measured CO and HC values, as well as a printout in red for the excessively high pollutant levels that justify a complaint about the engine "

70980770301

Claims (64)

Expectations 1. Procedure for testing a vehicle internal combustion engine on the emission of pollutants contained in the exhaust gas, in which the vehicle with its drive wheels on the rollers a dynamometer is put on, wherein at least one of the dynamometer rollers with a power consumption unit is connected, which automatically applies a load to the machine that is approximately the third power changed with the speed of the roller, an exhaust gas sample being taken from the exhaust system of the vehicle, wherein further the engine of the vehicle for a short period of time according to a first mode among a first predetermined load is operated according to a given vehicle weight class, the machine with a first predetermined speed and the first load running; in which further the amount of CO and HC in the exhaust gas sample while the engine is running at the first predetermined load and speed; in which the engine during a further short time interval corresponding to a second mode with a second, different predetermined one Load is operated at a second different speed according to the given vehicle weight class, in which the amount of CO and HC contained in the exhaust gas sample is measured while the engine is below the second predetermined one Load and speed running; that the engine is under for a further period of time according to a third mode Idling speed loaded and the proportion of CO and HC in the exhaust gas is measured at idling speed; in the further the measured CO and HC values for the three modes with prescribed permissible values for the respective modes 7093 07/0301 are equalized and it is determined whether the measured values exceeds the permissible values in one of the test modes and thus reveal possible damage to the engine. 2. The method according to claim 1, characterized in that when the vehicle engine is running, the oxygen content measured in the exhaust gas of the engine, the measured value of oxygen compared with a predetermined limit and determined becomes whether the engine is working richer or leaner than stiochiometric; that the exhaust system is pressurized when the measured oxygen value exceeds the first or second limit value, and that the measured oxygen values before and after pressurizing the exhaust system can be compared to determine whether the oxygen content after pressurization has decreased by a predetermined percentage has fallen below the oxygen value that was before the Pressurization was measured to determine if there was a leak in the exhaust system when the system was running is not under pressure. 3. The method according to any one of claims 1 or 2, characterized marked that in vehicles of over 1.7 t the engine is loaded at about 27 to 30 BS at speeds corresponding to about 48 to 50 mph. 4. The method according to any one of claims 1 or 2, characterized characterized in that in a vehicle of at least 1.7 t weight, the engine at speeds that one speed correspond to 32 to 35 mph, with a load is loaded by about 10 to 12 hp. 5. The method according to any one of claims 1 or 2, characterized characterized in that in a vehicle of about 1.3 t to 1.7 t the engine at a speed corresponding to 44 to 46 Miles per hour with a load of about 21 to 24 horsepower. 70 980 7/030 1 6. The method according to any one of claims 1 or 2, characterized in that in a vehicle with a weight from 1.3 t to 1.7 t the engine at a speed corresponding to 29 to 32 miles per hour with a load of about 8 to PS is loaded. 7. The method according to any one of claims 1 or 2, characterized in that in a vehicle with a weight from 0.8 t to 1.3 t the engine with a speed corresponding to 36 to 38 miles per hour with a load of about 13 to 15 HP is loaded. 8. The method according to claim 1 or 2, characterized in that in a vehicle from 0.8 t to 1.3 t weight of the engine is loaded with a load of about 4 to 6 horsepower at a speed corresponding to 22 to 25 miles per hour. 9. The method according to any one of the preceding claims, characterized in that the engine according to a fourth Mode is checked by the fact that the engine is operated at full throttle for a short time interval that the amount of CO and HC contained in the exhaust gas measured at full throttle and the measured values of CO and HC with the prescribed permissible values for full throttle are compared. 10. The method according to any one of the preceding claims for testing a vehicle with a TSAD-NO post-combustion device is equipped, characterized in that the engine with a higher load than when idling is operated that the amount of NO contained in the exhaust gas is measured when the highest and the next lowest Gear of the transmission is selected and that the measured values of NO are compared to determine whether the value of the Ji NO in the lower gear has decreased by a predetermined fraction of the value of 0 in the highest gear. 709807/0301 11. The method according to any one of claims 1 to 9 for testing of a vehicle with a SAD-NO post-combustion device is equipped and contains an ignition timing controller, which is connected by a vacuum line to a vacuum source of the engine, characterized in that, that the engine is operated at a load greater than that for idling; that the content of NO in the waste gas is measured once with the afterburner switched on and then with the afterburner disconnected; that the rate of vacuum rise is measured in the vacuum line if it is connected to the regulator in the normal way; that the measured values of 0 with the afterburner switched on and separated afterburner to determine whether the level of NO is compared to separated SAD afterburner exceeds a predetermined fraction of the measured value UO with an effective afterburner, and that the measured negative pressure increase is compared with a predetermined limit value. 12. The method according to any one of claims 1-9, for testing of a vehicle equipped with an EGR-NO post-combustion device is equipped, characterized in that the engine is operated with a greater load than valid for idling is that the content of NO in the exhaust gas once with connected ERG afterburner and once with separated ERG afterburner is measured; that the measured Values of NO are compared to determine whether the value of N0 "with separated EGR afterburner by a predetermined percentage above the value of NO with connected EGR afterburner has exceeded. . 13. The method according to any one of claims 1 to 9 for testing of a vehicle that is equipped with an SSAD-NO " and includes an ignition timing controller via a vacuum line with a vacuum source of the machine 709807/0301 is bound, characterized in that the machine is operated with a preselected load over idle; that the speed of the motor is measured; that the vacuum in the vacuum line is checked for its presence, when the engine speed has reached a first limit to determine if the SSAD afterburner is at that speed is working; that the engine speed is increased until a negative pressure is detected in the vacuum line or a second predetermined speed limit is reached; that the value of NO in the vehicle exhaust gas at a speed is measured when the vacuum is first detected in the vacuum line, namely when the SSAD afterburner is switched on and when it is not effective; and that the measured values of NO with effective SSAD- Afterburner and when the SSAD afterburner is ineffective can be measured to determine whether the value of NO has increased decreased by a specified percentage after the SSAD afterburner was started. 14. The method according to any one of claims 2 to 13 for a Vehicle which is equipped with an air supply to the exhaust system, characterized in that the measured oxygen value with the exhaust system set under negative pressure with a first or second predetermined limit value is compared to determine if the air injection system is effective. 15. Device, in particular for carrying out the method according to one of the preceding claims, for checking the exhaust gas development of an internal combustion engine for determination of machine damage, which manifests itself in the composition of the exhaust gas, with a power annihilation unit, which applies a selectable load to the engine at a specified engine speed, with an exhaust gas analyzer 7098.07 / 03 0 1 calibrating device connected to the exhaust of the engine and allows a quantitative measurement of at least one gas contained in the engine exhaust gas. 16. The device according to claim 15, characterized in that that a load signal generator is provided which outputs load signals proportional to the load; that a comparator is connected to the exhaust gas analyzer and responds to the load signals and the measured Compares the value of the gas detected in the exhaust gas with an acceptable value; and that an output signal generator is provided which is connected to the comparator and a Output generated when the measured value of the gas remains below or exceeds the acceptable value. 17. Apparatus according to claim 15 or 16, characterized in that that the exhaust gas analyzer determines the content of carbon monoxide, (CO) and hydrocarbons (HC) in the exhaust gas allows to measure and emits corresponding output signals. 18. The device according to claim 17, characterized in that that a signal stabilizer on the CO and HC signals responds to the exhaust gas analyzer and generates stabilized CO and HC signals when the output signals from the Signal stabilizers have stayed within a predetermined range for a predetermined time interval. 19. Device according to one of claims 15-18, daduröh characterized in that the load comparison device a Circuit for monitoring the load for the motor and BATH 709807/0 30 1 comprises for generating a load release signal when the load is over within a predetermined range remains away for a given time interval. 20. Device according to one of claims 15 to 19, characterized in that the comparator compares the measured values with acceptable values for the gas when the engine load falls into at least two separate ranges. 21. Device according to one of claims 15 to 20, characterized in that the output signal generator generates a separate failure output indicating excess gas for each exposure range. 22. Device according to one of claims 15 to 21, characterized in that a memory circuit for the failure signals is provided. 23. Device according to one of claims 15 to 22, characterized in that a failure indicator on each which responds to the stored output signals and provides an indication of engine failures. 24. Device according to one of claims 15 to 23, characterized in that the load signal is a speed signal which is proportional to the engine speed, and that the comparator takes the measured value of the determined Compares gas with acceptable values for the gas when the engine speed is in the range of 1,700 to 3,200 rpm (high Speed) is in the range of 60% to 70% of the mentioned speeds (low speed), and lies in the idle speed range. 709807/0301 • Wed 25. Device according to one of claims 15 to 24, characterized in that the load signal is a Is speed signal proportional to engine speed; and that the comparison means the measured Value for the gas with acceptable values for the gas compares when the engine speed is in the range of 1,700 to 3,200 rpm and falls into the idle range. 26. Device according to one of claims 15 to 25, characterized in that the load signal is a The speed signal is proportional to the engine speed is; and that the comparator determines the measured value of the Gases compares with acceptable values for the gas when the engine speed is in a speed range of 1,200 to 2,200 rpm (slow speed) and falls within the idle speed range. 27. Device according to one of claims 15 to 26, characterized characterized in that the comparator compares the measured value of the gas with acceptable values of the gas, when the engine load falls within a range of 35% to 75% of the maximum torque developed by the engine at high RPM drops, and when the engine load falls into a range drops from 30 to 50% of the selected high speed at low speed * 28. Device according to one of the preceding claims, characterized in that the comparator is the measured Comparing the value of the gas with acceptable values for the gas when the engine load is in a range of 35% up to 75% of the maximum torque developed by the engine falls at high speeds and when the engine load of the Is idling. 709807/0301 29. Device according to one of claims 15 to 28, characterized characterized in that the comparison means match the measured value of the gas with acceptable values of the Gases compares when the engine load is in a range from 18% to 40% of the maximum torque that the engine can develop drops at low speed and when the engine load is according to idle. 30. Device according to one of claims 15 to 29, characterized in that the power consumption unit an engine load of 35% to 75% of the maximum torque that can be developed by the engine at a high speed range and developed an engine load of 30% to 50% of high speed at low speed range. 31. Device according to one of claims 15 to 30, characterized in that a control device for changing the engine load provided in the power consumption unit is a change in engine load corresponding to at least two classifications of engine sizes enables. 32. Device according to one of claims 15 to 31, characterized characterized in that the failure indicator provides a printed indication of engine failure. 33. Device according to one of claims 15 to 32, characterized characterized in that the exhaust gas analyzer allows the content of nitrogen oxides (NO) in the exhaust gas to be measured. 34.Vorrichtung according to any one of claims 15 to 33, characterized characterized in that the exhaust gas analyzer allows the content of oxygen in the exhaust gas to be measured. 7 0 9 8 Ö 7/0 3 0 1 35. Device according to one of claims 15 to "34, characterized in that a load index meter has an input connection applicable to the measured load and an input port applicable to the desired load, a scale with a middle zone and one has movable pointer and is designed so that the The pointer is in the middle when the amplitude of the applied to the connection valid for the measured load Signal remains in a predetermined range, and that the pointer to one side or the other of the middle Range deflects when the amplitude of said signal is greater or less than the predetermined range; that the connection of the load index meter that is valid for the measured load with the load signal source and the connection valid for the desired load with a reference signal source are coupled 36. Apparatus according to claim 35, characterized in that load indicators are provided which respond to the load signal and the signal designating the desired load and indicate that the engine load should be kept constant or should be changed. 37. Device according to one of claims 15 to 36, characterized characterized in that the exhaust gas analyzer has at least two Gases from the exhaust gas to be measured; that the comparator compares the measured values of the gases with acceptable values of the Compares gases when the engine load is in a range falls with high speed, a low speed range and an idle speed range? and that the output signal generator separate failure signals are generated which show the excess of each of the gases in the exhaust gas at the individual Represent speeds. 709 807/030 1 38. Apparatus according to claim 37, characterized in that that a memory circuit for each of the selection signals is provided. 39. Device according to one of claims 15 to 38, characterized characterized in that the selection indicator comprises a matrix that allows the selection of at least one of a plurality has predetermined reports as a function of the stored failure signals for each of the measured gases, wherein each report contains the probable causes and instructions on how to correct them. 40. Apparatus according to claim 38 or 39, characterized in that the two gases carbon monoxide and hydrocarbon are; that the matrix provides an initial report in response to carbon monoxide related failure signals Idle speed and absence of carbon monoxide failure signals generated at high speed and a second report in response to a carbon monoxide failure signal generated at high and / or low speed and in the absence of carbon monoxide failure signals at idle speed, a third report based on a carbon monoxide failure signal at high speed and at idle speed, a fourth report for a hydrocarbon failure signal while idling and in the absence of a hydrocarbon failure signal generated at high RPM, a fifth report on a hydrocarbon failure signal at high and / or low speed and in the absence of a hydrocarbon failure signal at idle speed, and finally a sixth report is generated when a hydrocarbon failure signal occurs is present at high speed and idling. 709807/0301 41. Device according to one of claims 15 to 40, as through characterized in that the stabilized in the comparator CO and HC signals are compared to the acceptable values of · CO and HC when the engine is in each test mode has been operated for a predetermined time interval. 42. Apparatus according to claim 41, characterized in that the output signal generator is connected to the comparator and generates separate pass or failure signals for each gas and test mode if the stabilized gas signals remain below acceptable values or exceed the same. 43. Device according to claim 42, characterized in that that an engine digest indicator is provided that on which responds to pass and failure signals and prints out an indication of the suspected engine damage. 44. Device according to one of claims 41 to 43, characterized in that the gas signal stabilizer a device for measuring the rate of change which contains CO and HC signals. 45. Apparatus according to claim 44, characterized in that that the gas signal stabilizer has a magnitude comparator to compare the CO and HC signals with acceptable values which has gases for each test mode and generates stabilized CO and HC gas signals when the gases are below acceptable levels Values fall. . 46. Apparatus according to claim 44, characterized in that the gas stabilizer has a speed comparator for comparing the rate of change of the CO and HC signals, which contains the rate of change compares with a predetermined signal range for a predetermined time interval. 709807/0301 47. Device according to one of claims 45 and 46, characterized in that a control device is coupled to the power consumption unit, which the power consumed by the unit at different The engine speed can be changed according to the different vehicle classifications, 48. Device according to one of claims 15 to 47, characterized in that a sequence circuit is provided, sequentially the gas signal comparator with predetermined acceptable values of CO and HC for each test mode of the engine provided. 49. Device according to one of claims 15 to 48, characterized in that a tachometer with the dynamometer is coupled, which determines the speed of the vehicle wheels. 50. Apparatus according to claim 49, characterized in that the gas signal comparator is responsive to the rotational speed of the vehicle wheels and compares the stabilized and acceptable values of CO and HC when the rotational speed of the vehicle wheels is within a predetermined range. ^ _- 51. Apparatus according to claim 49, characterized in that the dynamometer different loads on the engine can charge at least two different vehicle weight classes for each test mode. 52. Device according to one of claims 15 to 51, characterized characterized in that the prescribed test modes for the engine include a high speed mode with a Engine speed from 1,700 to 3,200 rpm, a low-speed mode, in which the engine runs at a speed 709807/0301 which does not exceed 40% of the speed at high speed <■ ability mode, as well as an idle mode. 53. Device according to one of claims 15 to 52, characterized in that the dynamometer has a load in the area from 35% to 75% of the maximum torque of the motor at high speed and a load of less than 50% the load on the engine at high speed in the low speed mode. 54. Device according to one of claims 15 to 53, characterized characterized in that a recording device is provided, with which the individual failure signals for each gas and each test mode is provided; and that the engine diagnostic indicator several separate preprinted engine failure quotes and a selector to choose one of several Forms depending on the sequence of failure signals having. 55. Device according to one of claims 15 to 54, characterized characterized in that the engine is equipped with a device for regulating the content of nitrogen oxides in the exhaust gas is aligned, and that the exhaust gas analyzer generates an NO signal for the quantitative measurement of the NO content in the exhaust gas is representative, and that an NO indicator is provided, which responds to the NO signal for the corresponding appeals to the ad. 56. Device according to one of claims 15 to 55, characterized characterized in that an index circuit is provided on the load index meter which sends a signal accordingly of the measured load for the measuring device and sequentially a load signal to the reference input of the measuring device according to the selected loads for the respective test. 709807/030 1 57. Apparatus according to claim 56, characterized in that the load signal is transmitted to the vehicle wheels Torque is proportional. 58. Apparatus according to claim 15, characterized in that that a dynamometer chassis has at least one roller which is supported by the driven wheels of the vehicle are loaded that the dynamometer has a power dissipation unit connected to the roller is and allows the application of predetermined loads to the machine in each test mode; that a speed generator with the dynamometer to generate a signal representing the speed of the vehicle drive wheels is coupled; that an exhaust gas analyzer is coupled to the exhaust system of the engine and at least one allows first and second gas to be measured and emits gas signals, each gas signal for the quantitative Measurement of the amounts of gas contained in the exhaust gas is representative; that a speed comparator one with the rotary signal generator coupled input, a reference input and an output, wherein the speed comparator the Speed signal with a reference speed range signal compares and emits an output signal when the speed signal is in the reference speed signal range during a predetermined period of time remains; that a gas stabilizer is responsive to the first and second measured gas signals and a stabilized first and second gas signal is generated when the measured gas signals are in a predetermined value range remain over a predetermined time interval; that a first gas comparator with a first gas inlet is connected to the first gas stabilizer, has a first gas reference input and an output, the first Gas comparator as a function of the output signal of the speed signal generator the stabilized first Compares the gas signal with a first gas reference signal and generates a first gas pass or gas failure signal, 709807/0301 if the stabilized first gas signal is the first gas reference signal falls below or exceeds; that a second gas comparator with a second gas inlet to a second Gas stabilizer is connected, a second gas reference input and having an output, wherein the second gas comparator is dependent on the output signal of the speed signal generator compares the stabilized second gas signal with a second gas reference signal and generates a second gas signal at the output when the stabilized second gas signal falls below or exceeds the second gas reference signal; and that an automatic Control device sequentially predetermined speed reference range signals to the reference input of the speed comparator as well as preselected first and second throttle reference signals to the reference inputs of the first and second gas comparators for sequential testing of the engine for each prescribed test mode is present. 59. Apparatus according to claim 58, characterized by a recorder for recording a first and second gas inventory or failure signal. 60. Apparatus according to claim 59, characterized by a Engine diagnostic indicator that works on the pass and failure signals responds and outputs a printed display of possible vehicle damage. 6 "Ti device according to claim 60, characterized in that that the first and second gases are carbon monoxide and hydrocarbons are. 62. Apparatus according to claim 58, characterized in that that the exhaust gas analyzer can generate an NO gas signal, 7 0 9 8 0 7/0301 2 £ 3388 0 that represents the measured amount of NO content in the exhaust gas; that the gas stabilizer on the NO signal responds and generates a stabilized NO gas signal when the NO signal is within a predetermined range of values remains over a given period of time; that a NO- Ji Gas comparator with an NO gas inlet to the NO gas stabilizer X X connected, a NO reference input and a ji Having output, the NO gas comparator depending on the output signal of the speed signal generator ' the stabilized NO gas signal with an NO gas reference X X signal compares and a NO gas pass or failure signal generated when the stabilized NO gas signal exceeds the NO gas reference signal above or below. 63. Apparatus according to claim 61 or 62, characterized in that the exhaust gas analyzer generates an O ^ gas signal which is representative of a quantitative measurement of the oxygen content in the engine exhaust gas; that the gas stabilizer is responsive to the O ₂ signal and generates a stabilized O ₂ gas signal when the O ₂ signal remains in a predetermined range of values for a certain period of time; that the O ₂ gas comparator has an O ₂ gas reference input and an output, the O _{2 gas comparator comparing the stabilized O 2} gas signal with an O ₂ gas reference signal and an O ₂ gas signal as a function of the output signal of the speed signal generator Emits pass or failure signal when the stabilized O ₂ gas signal falls below or exceeds the O _{2 gas reference signal;} and in that a circuit ₂ -Gasreferenzälgnals is provided at the reference signal input of the ₂ 0 ~ Gaskomparators during at least one of the test modes for applying a predetermined O. 709807/0301 64. Device according to one of claims 60 to 63, characterized characterized in that the second gas comparator is additionally responsive to the stabilized CO gas signal. 709807/0 301