DE2640942A1 - COMBUSTION ENGINE - Google Patents

Description

PATENT ADVOCATES A. GRÜNECKER

H. KINKELDEY

DR-IISIG

W. STOCKMAlR

DR-INa · MICHLTECH

K. SCHUMANN

P. H. JAKOB

DlPL-INa

G. BEZOLD

DR FERNAT- DIFL-CHEM.

8 MUNICH

MAXIMILIANSTRASSE

Sep 10, 1976 P 10 832

Nissan Motor Company, Limited

. 2, Takara-machi, Kanagawa-ku, Yokohama City, Japan

Internal combustion engine

The present invention relates to an engine system. The engine exhaust contains harmful components, such as nitrogen oxides (NO), carbon monoxide (CO),

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Hydrocarbons (HC). Among them, the emission of Ν0 _{χ can be} reduced by dampening the combustion in a combustion chamber. But dampening the combustion will lead to an increase in CO and HC emissions. Therefore, there is a difficulty in suppressing NO, CO and HC emissions at the same time.

As one of the measures for suppressing Ν0 _χ ~ / CO and HC emissions _{at the same time, it is known to reduce the formation of Ν0 χ} by impairing the combustion with a high degree of exhaust gas recirculation (EGR) and by using CO - and HC components within a crash

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! converters reduced or reduced, such as in a thermal reactor, an exhaust gas converter, which is installed in the exhaust system of the engine. The increase however, the EGR level will make stable combustion difficult. To alleviate this problem, an engine system was created proposed in which the combustion of a relatively rich air-fuel mixture with a high EGR degree is ignited by a torch-like flame, which in an auxiliary combustion chamber is generated, and the CO and HC components in the exhaust gases that originate from the combustion, are reduced by an exhaust gas converter that is installed in the exhaust system. This engine system has the following problems. One problem is that during a certain operating condition of the engine the CO and HC emissions exceed the conversion capacity of the exhaust gas converter. Another problem is that there is a considerable loss of power output and economical fuel use.

It is therefore a primary object of the present invention to provide an engine system that has NO, CO and HC emissions lower levels under all engine operating conditions without loss of engine performance. ·

Other objects and features of the present invention will appear from the following description taken in conjunction with FIG accompanying drawing, in which the figure is a schematic diagram illustrating an engine according to the invention shows.

The preferred embodiment is described below with reference to the figure.

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In the figure, the reference numeral 1 shows an air filter, 2 a carburetor, 3 an inlet or intake duct, 4 a Main section of a combustion chamber, the main section 4 occupying a main area of the combustion chamber, 5 an auxiliary section of the combustion chamber, which is connected to the main section 4 via a connecting nozzle or -opening communicates, 7 an exhaust duct and 8 a thermal reactor for the oxidizing reaction of CO and HC components of the engine exhaust. The thermal Reactor 8 has a volume which is 1 to 4 times the total displacement volume of the associated motor has and is constructed in such a way that it has a sufficient residence time for an adequate reaction of HC and CO provides.

The main section 4 is provided with an inlet valve 9 and an outlet valve 10, but the auxiliary section 5 stands only in connection with the section and is not provided with such valves. The auxiliary section 5 is provided with a spark plug 11.

The introduction of a combustible mixture into the auxiliary section 5 and the purging of the exhaust gases from the auxiliary section is through the connecting opening 6 depending on the movement of a reciprocating piston within of a cylinder. The combustible mixture in main section 4 is ignited by combustion products, the combustion initiated by the spark plug 11 in the auxiliary chamber 5 result.

The reference numeral 12 shows the inlet port mouth to the main sections 4 and 13 to an outlet port mouth Main section 4 is. The outlet opening 13. is with a Air injection nozzle 15 of a secondary air injection system 14 is provided, as well as with a cavity lining 16. The provision

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a Hohlraumausklexdung 16 is the heat loss from the Reduce exhaust gases passing through outlet port 13 to a minimum.

The secondary air injection system 14 also has a check valve 17, an air duct 18, an air pump 19 and a control valve 20. The air pump 19 is driven by the engine. The control valve 20 is flexible with a Diaphragm 21 connected, which deflects as a result of the engine intake vacuum, so that during an engine operating state, in which the intake vacuum is low, such as during high engine operation Load, the air duct 18 is vented to allow the secondary air to escape into the environment to prevent the injection of Reduce or prevent secondary air in the exhaust gas duct 13. To prevent secondary air being blown in, when the temperature inside the thermal reactor 8 is abnormally high, a solenoid valve 24 is provided to open a vacuum line 23 or to close, which transmits the suction negative pressure to a negative pressure chamber which is limited by the membrane 21 will. If the temperature inside the thermal reactor 8 exceeds a predetermined value, then leave a temperature sensor 22, which is attached to the thermal reactor 8, a current through a coil of the solenoid valve 24 flow, wherein he ventilates the vacuum line 23 to it. allow the ambient air to enter the vacuum chamber, which is limited by the membrane 21 to penetrate. Then the control valve 20, which is connected to the ί (membrane is connected, by means of a diaphragm spring, which is normally the membrane 21 biases downward, as can be seen in the drawing, moves into a ventilation position.

CO and HC components of the exhaust gases emitted by the engine are oxidized within the thermal reactor 8 with the supply of secondary air. The part of the exhaust duct 7,

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which is closer to the thermal reactor 8 is adiabatic with one Layer 25 provided in order to prevent the oxidation of non-oxidized or partially oxidized CO or HC constituents during the discharge the thermal reactor 8 to promote.

One end of the air duct 18 has an opening to one adiabatic space 25a between the outer pipe, the exhaust gas duct and the inner pipe 25. The space 25a serves as a channel that connects the channel 18 with the air injection nozzle. It should be noted that the secondary air with the exhaust gases, passing through the inner tube 25 is heated. Preheating the secondary air will keep the temperature within the prevent thermal reactor from sinking and this is the temperature of the thermal reactor high enough for the Keep oxidation of CO and HC.

A duct 26 connects the exhaust duct 7 with the intake duct 3. An exhaust gas recirculation control valve (EGR control valve) 27 is provided, to control the flow of exhaust gases passing through duct 26. · '

The EGR control valve 27 is controlled by a diaphragm device 28 actuated, which is movable as a function of the suction vacuum. The flow rate of the returning exhaust gas should can be set to a value within a range of 5% to 30% of the flow rate of the intake air.

Reference numeral 29 denotes a pre-silencer and 30 a main silencer. Front silencer 29 and main silencer 30 are connected to each other by a channel 7 'which is encased by a protective wall 31 for the purpose is to prevent exhaust heat from reaching the floor of the vehicle body and dry grass on the surface of the earth inflamed.

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To the temperature of the intake air for proper gasification To keep the fuel and distribute the fuel is a switch valve 34 in an air line 33 provided upstream of the air cleaning element 32 to the flow of relatively warm air from a Warm air supply line 35 in the air filter 1 and from relatively cold air from the line 33 in. the air filter 1 to control.

The warm air supply line 35 is at one end the air line 33 and connected at its other end to an air heating chamber 54, which the exhaust duct 7 at the Sheathed part provided with the inner adiabatic tube 25 so that the air is heated with the exhaust gases.

The switching valve 34 is connected to a membrane device 36 in operative connection in order to be actuated depending on the suction vacuum in such a way that the portion the warm air increases in relation to the cold air when the intake vacuum decreases. A trigger-sense valve, not shown is provided on the membrane device 36 in a negative pressure. When the temperature of the intake air has a exceeds a predetermined value, then the transfer of the suction negative pressure to the diaphragm device 36 prevented by the temperature-dependent trigger-sense valve, wherein the switching valve 34 is biased in a direction that only cold air is admitted into the air filter 1 will.

To prevent a sudden increase in the intake manifold vacuum during a sudden deceleration operation of the engine, in order to prevent an increase in CO and HC, either a throttle opener 38 or a part thereof, which is a throttle valve, is provided 39 prevents you from moving through a slightly open position to the idle position when the suction vacuum

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is relatively high, or a damper 40 is arranged, which prevents the throttle valve 39 from closing quickly. If the suction vacuum is high enough, how for example, during the decelerating operation, is due to a decrease in the compression pressure and an increase of the residual gas suppresses the combustion, which leads to an increase in CO and HC. The increase in CO and to prevent HC, the throttle opener 38 holds the throttle valve 39 in a slightly open position, the one Has greater width than the idle position when the intake vacuum is high, because the diaphragm device of the Throttle opener 38 is in action with the throttle valve 39 connection and is exposed to the suction negative pressure, whereby there is a sufficiently large amount of air around the throttle valve 39 can flow into the intake duct 3 to prevent the suction negative pressure rises above a predetermined level. The damper 40 acts to dampen a sudden Closing movement of the throttle valve 39; a sudden increase in suction pressure due to the sudden To prevent closing of the throttle valve 39.

The reference numeral 41 denotes a valve against afterburning, which is provided in a channel 42, from the air filter 1 to the intake channel 3 downstream 'of the carburetor 2 leads. The valve 41 is controlled by a diaphragm valve 43 actuated that when exposed to the negative intake pressure

is operable to allow valve 41 to allow air to enter the intake passage 3 is supplied when the suction negative pressure is high.

When the intake negative pressure increases, the fuel adhering to the inner wall of the intake passage 3 becomes the intake negative pressure sucked into the combustion chamber, which leads to a temporary enrichment of the air-fuel mixture, which could cause an ignition failure in the combustion chamber.

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If ignition errors or misfires occur, then air-fuel mixture in the exhaust system, in particular in the thermal reactor 8, burn and thereby lead to damage to the thermal reactor 8.

To prevent the above-mentioned phenomenon from occurring, the air duct 42, the valve 41 and the associated membrane device 43 are provided. It will. On it pointed out that the sudden increase in suction pressure which the introduction of the fuel could cause, which adheres to the inner wall of the intake duct 3, thereby preventing additional air from entering the intake duct 3 is supplied through the air passage 42 when the suction negative pressure is high. Numeral 45 denotes a Vacuum device for the distributor 46 to adjust the pre-ignition. The vacuum device for adjusting the Pre-ignition 45 causes the advance adjustment due to negative pressure the ignition point is reduced when the intake negative pressure increases in order to increase the exhaust gas temperature, to promote the oxidation of CO and HC components in the exhaust gases.

The vacuum device for adjusting the advance ignition 45 is connected to the intake duct 3 through a vacuum line 47 tied together. A ventilation duct 48, which is provided with an electromagnetic valve 50, is provided towards the vacuum line 47 is that normally closes the ventilation duct 48 and it during engine operation at high speed opens. The engine operation at high speed is detected by an engine tachometer 51 which causes the coil of the solenoid valve 50 is energized when the engine speed is higher than a predetermined value. So is the ignition timing is set to full advance during engine operation at high engine speed, even if the intake vacuum is high. The high speed engine operation can be performed by an engine tachometer 51 instead of an engine tachometer 51 Switches can be tracked that indicate the switching position of the power transmission measures.

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The reference numeral 37 indicates a device for preventing further operation in order to complete the fuel supply, when the engine stops. .

Reference numeral 52 denotes a cold spark advance circuit which causes the distributor 46 to be set to full spark advance during cold engine operation. The cold engine operation is detected by an engine coolant temperature sensor 53 - the sensor 5Qr. causes switch 52 to be closed when the engine coolant temperature is below a predetermined value. A full advance of the ignition point during cold engine operation is necessary to warm up the engine quickly.

The mode of operation of the engine system described above will now be explained below. During the suction cycle is a rich air-fuel mixture, which is produced by the carburetor 2, in the combustion chamber together with sucked in the exhaust gases returned to the exhaust duct 3. The air-fuel mixture mixed with the exhaust gases becomes initially introduced into the main section 4 of the combustion chamber via inlet 9. . ·

During the engine's compression stroke, part of the combustible charge in the main section 4 is pushed into the auxiliary section 5 through the connecting opening 6.

At the point of ignition, the spark plug 11 provides a spark, to initiate the combustion within the auxiliary section 5. The combustion products or flame resulting from the combustion in the auxiliary section 5 shoots in the main section 4 in order to trigger the combustion in this. This combustion arrangement allows a stable one Combustion with a high EGR content, causing a considerable reduction in the formation of NO

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With the combustion arrangement, a relatively large amount of residual gas remains around the spark plug 11, because the auxiliary section 5 is not provided with an inlet valve or an outlet valve. This prevents and reduces the formation of NO within an area around the spark plug 11, where mainly the formation of NO focused.

The exhaust gases emitted from the combustion chamber contain CO and HC. These CO and HC components become oxidized within the thermal reactor 8 and within the outlet channel 7, which is provided with an adiabatic inner tube 25 is provided, with the help of the secondary air from the secondary air injection system 14. Contain the exhaust gases a suitable amount of CO to provide a better oxidizing atmosphere, because the carburetor delivers a relatively rich air-fuel mixture. It has been confirmed that the Volume of the thermal reactor 1-4 times the total displacement of the engine should be to allow a suitable residence time of the exhaust gas for adequate oxidation of the HC and CO.

The supply of secondary air into the intake duct 3 or the Exhaust gas duct 7 should be set in such a way that the exhaust gases after mixing with the supplied secondary air an air to fuel ratio in the range of 16 to 18 exhibit.

During engine operation under high load, in which the temperature of the exhaust gases is sufficiently high and the CO and HC components of the exhaust gases are relatively low, the membrane device 21 opens the valve 20 to the To ventilate the secondary air duct 18 so that the supply of secondary air into the outlet opening 13 is prevented or at least is decreased. This control of the secondary air

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during engine operation at high load is required to prevent the thermal reactor 8 from overheating.

The prevention of the supply of secondary air into the outlet port 13 is carried out when the temperature of the thermal Reactor 8 becomes abnormally high. This is brought about by the temperature sensor 22, which is located on the thermal reactor 8 is attached, and through the solenoid valve 24. When the temperature in the thermal reactor 8 is a predetermined Exceeds the value, then the temperature sensor 22 allows the solenoid valve 24 to ventilate the vacuum line 23, to allow the valve 20 to ventilate the secondary air duct 18. The thermal reactor 8 can be through a catalytic converter be replaced.

During an abrupt deceleration engine operating condition where the chance of misfire increases, will. the valve 41 is opened to let air into the intake passage 3 to avoid an excessive increase in the intake negative pressure to prevent and thereby a temporary enrichment of the air-fuel mixture and the occurrence of afterburners to prevent. .

During an engine operation in which the intake negative pressure is high, such as during a Motorverzöge · ¹ 'rungsbetriebSfbewirkt the throttle opener 38 or the damper 40, that the immediate increase of the intake negative pressure is avoided, thus avoiding the increase of HC and CO. In order to additionally prevent a deterioration of the combustion condition, the vacuum line 47, which connects the intake vacuum to the vacuum adjusting device 45, is ventilated during the engine deceleration mode at high engine speeds, whereby the distributor is released to switch from a delayed ignition point to an early ignition point in order to which to-

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stand to improve combustion.

The warming up of the engine is promoted, since the circuit 52 for pre-ignition occurs during cold engine operation is closed during cold engine operation to cause the distributor 46 to advance the ignition timing to the To improve the state of combustion. Of course, it becomes relatively warm even when the engine is running cold Air introduced from the warm air duct 35 from the air filter 1 and thus improves combustion during cold engine operation, with engine operation stabilizing and the cleanliness of the engine exhaust is improved during cold engine operation.

When the temperature of the intake air is high, the air cleaner 1 is turned on by the action of the switching valve 34 prevents warm air from being introduced into the air, preventing a decrease in suction efficiency will.

On the basis of the foregoing, it is now pointed out that an engine system according to the invention reduces overall of NO, CO and HC under all engine operating conditions without any loss of engine power.

- Expectations -

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Claims (8)

26409A2 Expectations Combustion engine, marked with the following features:
a combustion chamber with a main section (4) and a secondary section (5) which is connected to the main section only via a connecting opening (6) between the main and secondary sections, a carburetor (2) with a throttle valve (39), an intake duct ( 3), which connects the carburetor only to the main section of the combustion chamber, an ignition device with a spark plug (11) which is connected to the secondary section of the combustion chamber for initiating ignition in the combustion chamber, an exhaust gas converter (8), an outlet device (13) to direct the exhaust gas resulting from the combustion in the combustion chamber to the exhaust gas converter,. .. an exhaust gas duct device (7, 7 ¹ ) / to direct the gases resulting from the conversion in the exhaust gas converter into the ambient air, a device (15) for blowing in secondary air, into the outlet device,. an exhaust gas recirculation device (26) to make it a part to allow the exhaust gases in the exhaust duct device to flow into the intake duct, and. means (38, 40) for controlling movement of the throttle valve towards a closed position during of the delayed engine operation in order to avoid a sudden increase in the intake vacuum in the intake duct. 2. Internal combustion engine according to claim 1, characterized in that that the control device comprises a device (38) to the throttle valve (39) in an open To hold if the suction vacuum is higher than 709813/0918 L INSPECTED a predetermined level. 3. Internal combustion engine according to Än claim 1, characterized in that that the control device has a device (40) for damping the movement of the throttle valve (39) has a closed position. 4. Combustion engine, characterized by the following features: a combustion chamber with a main section (4) and a secondary section (5) which is connected to the main section only communicates via a connecting opening (6) between the main and secondary sections, - a carburetor (2) with a throttle valve (39), an intake duct (3) that connects the carburetor only with the Main section of the combustion chamber connects an ignition device with a spark plug (11) which is in the The secondary section of the combustion chamber for initiating the ignition is arranged in the combustion chamber, an exhaust gas converter (8), an outlet device (11) for the exhaust gas resulting from the combustion in the combustion chamber to the exhaust gas converter to judge an exhaust gas duct device (7, 7 ¹ ) to direct the JSase resulting from the conversion in the exhaust gas converter into the ambient air, means (15) for blowing secondary air into the outlet device, - An exhaust gas recirculation device (26) to make it part of the To allow exhaust gases in the exhaust duct means to flow into the intake duct, and means (41) to to allow air to flow into the intake port when the intake vacuum in the intake port is higher than a predetermined level. 709813/0918 3 - 2840942 5. Internal combustion engine, characterized by the following Characteristics: a combustion chamber with a main section (4) and a secondary section (5) which is connected to the main section is in communication only via a connecting opening (6) between the main and secondary sections,. a carburetor (2) with a throttle valve (39), an intake duct (3), which only connects the carburetor with the Connects the main section of the combustion chamber, - An ignition device with a spark plug (11) which is connected to the secondary section of the combustion chamber for initiation the ignition in the combustion chamber is connected, - an exhaust converter (8), an outlet device (13) for the exhaust gas resulting from the combustion in the combustion chamber to the exhaust gas converter to judge an exhaust gas duct device (7, 7 ') in order to avoid the conversion convert the gases resulting from the exhaust gas converter into the ambient air, a device (15) for blowing secondary air into the outlet device, - An exhaust gas recirculation device (26) to make it part of the Allowing exhaust gases in the exhaust duct device to "flow into the intake duct, a device (45) for delaying the ignition point depending on the suction negative pressure in the intake duct, and . means (50) for enabling the means for later setting the ignition timing when the Engine speed is higher than a predetermined value. 6. Combustion engine, characterized by the following features: - A combustion chamber with a main section (4) and a secondary section (5) which is connected to the main section 709813/0918 - yr - only communicates via a connecting opening (6) between the main and secondary sections, - a carburetor (2) with a throttle valve (39), - an intake duct (3) that connects the carburetor only to the main section of the combustion chamber, an ignition device having a spark plug (11) connected to the sub-section of the combustion chamber for initiation the ignition in the combustion chamber is connected, - an exhaust converter (8), - An outlet device (13) for the exhaust gas resulting from the combustion in the combustion chamber to the exhaust gas converter to judge an exhaust gas duct device (7, 7 ¹ ) to direct the gases resulting from the conversion in the exhaust gas converter into the ambient air, a device (15) for blowing in secondary air into the outlet device, - An exhaust gas recirculation device (26) to allow a portion of the exhaust gases in the exhaust gas duct device to flow into the To flow intake duct, means (45) for retarding "the ignition timing in Dependence on the suction negative pressure in the suction channel, and a device for (52) releasing the device for Delays the ignition point when the flotortemperature is lower than a predetermined value. 7. Combustion engine, characterized by the following features: a combustion chamber with a main section (4) and a secondary section (5) which is connected to the main section only communicates via a connecting opening (6) between the main and secondary sections, - a carburetor "(2) with a throttle valve (39), - an intake duct (3) that connects the carburetor only to the main section of the combustion chamber, 709813/0918 - An ignition device with a spark plug (11) with is connected to the secondary section of the combustion chamber for initiating ignition in the combustion chamber, - an exhaust converter (8), - An outlet device (13) to remove that from the combustion direct the exhaust gas resulting in the combustion chamber to the exhaust gas converter, - An exhaust gas duct device (7, 7 ¹ ) to direct the gases resulting from the conversion in the exhaust gas converter into the ambient air, a device (15) for blowing in secondary air into the outlet device, - an exhaust gas recirculation direction (26) to allow part of the exhaust gases in the exhaust gas duct device to flow into the Intake duct to flow, and - a device (20). to prevent the supply of secondary air into the outlet device when the temperature inside the "exhaust gas reactor" is higher than a predetermined one Value" 8. Internal combustion engine, characterized by the following Characteristics: . a combustion chamber with a main section (4) ″ and a secondary section (5), which is connected to the main section only communicates via a connecting opening (6) between the main and secondary sections, * - a carburetor (2) with a throttle valve (39), - an intake duct (3) that connects the carburetor only to the main section of the combustion chamber, an ignition device with a spark plug (11), which with is connected to the secondary section of the combustion chamber for initiating ignition in the combustion chamber, - a thermal reactor (8), - An outlet device (13) for the exhaust gas resulting from the combustion in the combustion chamber to the exhaust gas converter to judge 70 9813/0918 - IXT- t - 26A0942 an exhaust gas duct device (7, 7 ¹ ) to direct the gases resulting from the conversion in the exhaust gas converter into the ambient air, a device (15) for blowing in secondary air into the outlet device, and an exhaust gas recirculation device (26) to allow part of the exhaust gases in the exhaust gas duct device, to flow into the intake duct, the thermal reactor having a volume which is 1 to 4 times of the displacement volume of the motor. 70981370918