JPS63219872A - Controller for engine - Google Patents

Abstract

PURPOSE:To suppress the deterioration of the traveling performance such as acceleration performance even if the engine output lowers in the delay angle control, by installing a control means for restricting an engine auxiliary which restricts the operation of the engine auxiliary in the delay-angle control for the ignition timing by an ignition timing control means. CONSTITUTION:A control means for restricting an engine auxiliary which restricts the operation of the engine auxiliary in the delay angle control for the ignition timing by an ignition timing control means is installed. Therefore, when the ignition timing is delay-angle-controlled by an ignition timing control means in the high load operation, the operation of the engine auxiliary which acts as the load for the engine is suspended. Therefore, even if the engine output is reduced by a certain degree by the delay angle control, the reduction quantity can be suppressed to the lowest limit, and the deterioration of the traveling performance such as acceleration performance can be suppressed.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an engine control device.

(Prior art) Knocking is a phenomenon of mechanical vibration caused by normal combustion (detonation) in an engine, in which the end gas (unburnt mixture at the end in the direction of flame propagation) spontaneously ignites before the flame propagates after ignition. This is due to the temporary rapid combustion caused by the spark ignition type engine.

Therefore, as a means for suppressing knocking in a spark-ignition engine, the knock intensity is generally detected by a knock sensor, and the ignition timing is retarded according to the detected knock intensity to maintain the combustion pressure near the top dead center of the piston. A method has been adopted in which the increase in the compression pressure of the end gas is suppressed to a predetermined range by lowering the compression pressure by a fixed amount (Special 11η 1982-28).
(See Publication No. 957).

(Problems that the invention is unlikely to solve) However, if the ignition timing is retarded as described above, the degree of isovolume during combustion will decrease and thermal efficiency will deteriorate. Therefore,
As a result, there is a problem in that engine output decreases and driving performance deteriorates. Although the engine knocking phenomenon is different from spark ignition engines in its mechanism of occurrence, it is also observed in diesel engines, and in order to suppress this phenomenon, for example, the fuel injection timing is set to the optimum timing for non-knocking. If the timing is shifted in a direction that deviates from the timing, the engine output may decrease. This deterioration in driving performance due to a decrease in engine output is particularly noticeable when various auxiliary equipment such as air conditioners and electric fans that act as a load on the engine are operating, and the deterioration in driving performance is particularly noticeable. cause deterioration.

(Means for Solving the Problems) The present invention has been made for the purpose of solving the above problems, and includes an operating state detection means for detecting the operating state of the engine, and a high load In an engine comprising an ignition timing control means that retards the ignition timing when an operating condition is detected, and an engine auxiliary machine that acts as an engine load during operation, retarding the ignition timing by the ignition timing control means. The engine auxiliary equipment restriction control means is provided for restricting the operation of the engine auxiliary equipment during control.

(Function) According to the above means, when the ignition timing control means retards the ignition timing during high-load operation, the engine auxiliary equipment that acts as a load on the engine stops its operation.

Therefore, even if engine output decreases to some extent by retarding the ignition timing, the amount of decrease can be suppressed to a minimum, and driving performance such as acceleration performance will not be significantly deteriorated. .

(Example) First, FIGS. 2 and 3 show an air-fuel ratio control device for an automobile gasoline engine in which the present invention is applied, and FIG. A schematic diagram of the system, FIG. 3 is a functional block diagram of the engine control unit in the control system.

First, the outline of the control system according to the embodiment of the present invention will be explained with reference to FIGS. 2 and 3, and then the control of the main parts will be explained.

In FIG. 2, reference numeral 1 is the engine body, and intake air is taken in from the outside via an air cleaner 30.
Thereafter, it is supplied to each cylinder via an air flow meter 2 and a storm throttle chamber 3.

Further, fuel is supplied from the fuel tank 12 to the engine side by the fuel pump 13 and injected by the fuel injector 5. The flow of intake air into the cylinder during running is controlled by a throttle valve 6 provided in the throttle chamber 3. The throttle valve 6 is operated in conjunction with the accelerator pedal, and is maintained at the minimum opening state in the idling state.

The throttle chamber 3 is provided with a bypass intake passage 7 that bypasses the throttle valve 6, and the bypass intake passage 7 is provided with intake air ffi! for controlling the engine speed during idling. A current-controlled solenoid valve (ISO valve) 8 is provided as a regulating means. Therefore, in the idle operating state, the intake air that has passed through the air flow meter 2 is supplied to each cylinder via the bypass intake passage 7, and the amount of intake air supplied is adjusted by the solenoid valve 8. The opening/closing state of the solenoid valve 8 is controlled by the duty ratio of a control signal supplied from an engine control unit (hereinafter abbreviated as ECU) 9.

Further, reference numeral 10 indicates an exhaust pipe provided with a three-way catalytic converter 11.

On the other hand, reference numeral 14 denotes an ignition plug provided in the cylinder head portion of the engine main body l, and the ignition plug 14
A predetermined ignition voltage is applied to the EC via the distributor 17 and the igniter 18, and the application timing of this ignition voltage, that is, the ignition timing is determined by the above-mentioned EC.
It is controlled by the ignition timing control signal Igc supplied from U9 to the igniter 18. Also, code 1
Reference numeral 9 denotes a knock sensor provided in the cylinder block portion of the engine main body 1, which outputs a voltage output Vo corresponding to the intensity of occurrence of knocking in the engine, and inputs it to the ECU 9. Furthermore, reference numeral 2o denotes a boost pressure sensor 20, which detects an engine boost pressure B corresponding to the engine load and inputs it to the ECU 9.

The ECU 9 includes, for example, a microcomputer (CPU) which is an arithmetic unit, a knock determination circuit, a memory (
ROM and RAM), interface (Ilo)
It is composed of circuits, etc. And this ECU
In addition to the above-mentioned detection signals, the interface circuit 9 includes, for example, an engine starting signal (ECU trigger) from a starter switch (not shown), and an engine rotation speed sensor 15.
Engine speed detection signal from N1 water temperature thermistor 16
Detection signal Tw of engine cooling water temperature detected by
1. For example, various detection signals such as a throttle opening detection signal TVO detected by the throttle opening sensor 4 and an intake air amount detection signal Q detected by the air 70 meter 2 are also input.

The ECU 9 is functionally equipped with a knock determination section 50 as shown in FIG. 3, and when the knock determination section 50 determines a knocking state, it performs knock suppression control to be described later. There is. The knock determination section 50 inputs the output voltage Vo of the knock sensor 19 (see FIG. 6) through the frequency discrimination filter circuit 30 for extracting only knock components, and performs knock determination within a certain period after ignition (knock determination). Period; see Figure 4 (a))
The next peak value detection unit 32 detects the peak value of the knock detection unit 32, while the comparison reference level calculation unit 33 calculates the average value (knock determination reference value) of the knock sensor output Vo when no knocking occurs within the above-mentioned knock determination period.・See Figure 4(b))
Calculate. Then, the knock determination unit 34 calculates both values.
When the peak value exceeds the average value, a knock signal is generated. This knock signal is manually inputted to a microcomputer 35, which is a calculation section, and the number of times the peak value exceeds the average value is calculated, and the knock intensity is determined according to the calculated value. This knock judgment value is the fourth
As shown in Figure (c), this is shown as a step-shaped signal waveform.

When the knock strength is determined as described above, the fourth
The judgment value shown in Figure (C) is converted into the waveform shown in Figure 5 (a), and the ignition timing of the next cylinder is retarded or advanced by feedback control according to the judgment value level to control the optimum ignition timing ( (See Figure 5(b)).

By the way, various engine auxiliary machines such as an air conditioner and an alternator are connected to the output shaft of the engine via disconnectable coupling means such as an electromagnetic clutch.

Next, the ignition timing control and auxiliary equipment cut control performed by the ECU 9 when knocking occurs will be explained in detail with reference to the flowchart of FIG. 7.

First, in the first step S, a double knock sensor 1 is used as a control parameter indicating the occurrence of knocking.
9 is input, and then in a second step S, a knock determination is performed by comparing the beater value of the input value VO with a predetermined comparison base or level. As a result, when the peak value of the output VO of the knock sensor 19 exceeds the comparison reference level (YES), it is recognized that knocking has occurred, and the process proceeds to the third step S3, where the ignition timing is adjusted according to the knock intensity. After calculating the retard amount, the process proceeds to a fourth step S4, where the ignition timing is retarded in accordance with the calculated value.

On the other hand, when the peak value of the output VO of the knock sensor 19 is lower than the comparison reference level Vs (NO), all control operations in the period are immediately terminated.

Next, when the ignition timing is retarded in the fourth step S4, the process proceeds to a fifth step S5 to determine whether or not it is necessary to cut the engine auxiliary equipment.

That is, in this embodiment, even if the ignition timing is retarded, the retard amount is relatively small below a predetermined value and does not reduce engine output to the extent that it causes deterioration of driving performance. It is considered that the operation of the auxiliary equipment can be continued as much as possible, and the decision to cut the auxiliary equipment is made for this purpose. Therefore, the determination is based on the boost pressure B and the engine rotation speed N, which indicate the engine load at that time.
Then, the auxiliary equipment cut area is specified on the map based on the differential value of the three rows of the above-mentioned ignition timing chart 1, and if the engine operating state at that time is within the auxiliary equipment cut area (YES
), the process proceeds to the sixth step s6 to cut the auxiliary equipment, while if not (NO), the auxiliary equipment cut is not performed. Then, along with the auxiliary machine cut, in the seventh step s7, the timer is set to a predetermined value Δt according to the retard amount, engine load amount, and rotation speed at that time, and the auxiliary machine is cut within the set time Δ, and then the above setting is performed. When the time Δt has elapsed, the process proceeds to an eighth step s8, and the cut auxiliary equipment is restored.

As a result, as shown in FIG. 8, for example, the engine is in an acceleration state that requires high torque when the engine auxiliary equipment is being driven. Even if the torque decreases as shown by the broken line, the engine auxiliary equipment is cut as described above, so the torque increases accordingly, and acceleration performance can be substantially improved.

Moreover, the above-mentioned auxiliary equipment cut and the cut time are appropriately set in consideration of the required torque return claw corresponding to the ignition timing retard amount, engine load, and differential value of the engine speed at that time, so that It is possible to avoid unnecessary cutting of auxiliary equipment even when there is no significant effect on performance deterioration. In this embodiment, the ignition timing is retarded when a knob king is detected, but the same effect can be obtained by applying the ignition timing to a retarder when an acceleration state is detected. Obtainable.

This is particularly effective in an acceleration state in a high load state where the throttle opening is at least a predetermined opening and the output correction due to the increase in intake air amount due to the opening operation of the throttle opening is not so great.

(Effects of the Invention) As described above, the present invention includes an operating state detecting means for detecting the operating state of an engine, and retards the ignition timing when a high load operating state is detected by the operating state detecting means. In an engine comprising an ignition timing control means for controlling the ignition timing, and an engine auxiliary machine acting as an engine load during operation, the engine auxiliary machine restricts the operation of the engine auxiliary machine when the ignition timing control means retards the ignition timing. This is characterized by the provision of machine restriction control means.

That is, according to the present invention, when the ignition timing control means retards the ignition timing during high-load operation, the engine auxiliary equipment that acts as a load on the engine stops its operation.

Therefore, even if engine output decreases to some extent by retarding the ignition timing, the amount of decrease can be suppressed to a minimum, and driving performance such as acceleration performance will not be significantly deteriorated. .

[Brief explanation of the drawing]

FIG. 1 is a claim correspondence diagram of the present invention, FIG. 2 is a control system diagram of an engine control device according to an embodiment of the present invention,
Figure 3 is a functional block diagram of the ECU in the control system, Figure 4 is a timing chart of the knock determination operation of the ECU, and Figure 5 is the timing of the ignition timing control signal during knock control of the ECU. 6 is a graph showing the waveform of the output signal of the knock sensor in the control nostem of FIG. 2, and FIG. 7 is a graph showing the waveform of the output signal of the knock sensor in the control system of FIG.
FIG. 8 is a flowchart showing non-king suppression control and auxiliary equipment cut control operations by U, and is a graph showing auxiliary equipment cut control characteristics during acceleration by the ECU. ll...Engine body 2...Air flow meter 5...Fuel injector 9...Engine control unit 14...
- Spark plug 17... Distributor 18... Igniter I9... Knock sensor 20... Boost pressure sensor

Claims (1)

[Claims] 1. an operating state detection means for detecting the operating state of the engine; an ignition timing control means for retarding the ignition timing when a high load operating state is detected by the operating state detection means;
In an engine comprising an engine auxiliary machine that acts as an engine load during operation, an engine auxiliary machine restriction control means is provided for restricting the operation of the engine auxiliary machine when the ignition timing control means retards the ignition timing. An engine control device featuring: