阅读说明：本技术 通过排气节流阀控制降低发动机熄火过程抖动的控制系统及其控制方法 (Control system and control method for reducing engine flameout process jitter through exhaust throttle valve control ) 是由 罗朝发 李文静 于 2019-11-29 设计创作，主要内容包括：本发明公开了一种通过排气节流阀控制降低发动机熄火过程抖动的控制系统及其控制方法。该通过排气节流阀控制降低发动机熄火过程抖动的控制系统包括：发动机,其排气端依次设置有发动机排气歧管和发动机排气总管；排气节流阀,其设置在所述发动机排气总管上；以及电控单元,其与所述排气节流阀控制连接,所述电控单元自动识别发动机的熄火工况,从而发出控制指令给排气节流阀使其关闭,其通过排气节流阀的关闭度增加排气阻力来增加缸内摩擦功来抑制和吸收飞轮在熄火过程中产生的抖动,能够有效降低整车的抖动现象,提高驾驶的舒适性。(The invention discloses a control system and a control method for reducing engine flameout process jitter through exhaust throttle control. The control system for reducing the jitter of the engine flameout process through the control of the exhaust throttle valve comprises: the exhaust end of the engine is sequentially provided with an engine exhaust manifold and an engine exhaust main pipe; an exhaust throttle valve provided on the engine exhaust manifold; and the electronic control unit is in control connection with the exhaust throttle valve and automatically identifies the flameout working condition of the engine, so that a control instruction is sent to the exhaust throttle valve to close the exhaust throttle valve, the exhaust resistance is increased through the closing degree of the exhaust throttle valve to increase the in-cylinder friction power to inhibit and absorb the shake generated by the flywheel in the flameout process, the shake phenomenon of the whole vehicle can be effectively reduced, and the driving comfort is improved.)

1. A control system for reducing engine misfire process chattering through an exhaust throttle control, comprising:

the exhaust end of the engine is sequentially provided with an engine exhaust manifold and an engine exhaust main pipe;

an exhaust throttle valve provided on the engine exhaust manifold; and

and the electronic control unit is in control connection with the exhaust throttle valve, automatically identifies the flameout working condition of the engine and sends a control command to the exhaust throttle valve to close the exhaust throttle valve.

2. A control system for reducing engine misfire process chattering through an exhaust throttle control as recited in claim 1 wherein an exhaust end of said engine exhaust manifold is provided with an exhaust muffler or aftertreatment device.

3. A control method of a control system for reducing the shake of an engine during flameout through the control of an exhaust throttle valve according to claim 1 or 2, characterized in that during flameout and shutdown, an electronic control unit automatically identifies the flameout condition of the engine, and then sends a control command to the exhaust throttle valve to close, so that the engine can generate large exhaust resistance during flameout to suppress and consume the rotation energy of the engine flywheel, and further suppress and absorb the shake of the flywheel during flameout.

4. The control method of a control system for reducing engine misfire process chattering through an exhaust throttle valve as recited in claim 3 wherein a degree of closing of said exhaust throttle valve reaches 90% -100%.

Technical Field

The invention relates to the field of engines, in particular to a control system and a control method for reducing engine flameout process jitter through exhaust throttle control.

Background

At present, in the process of flameout and shutdown of a general diesel engine, the engine is reduced from the idle speed (generally 600r/min-900r/min) to 0r/min through the self friction resistance, and the larger the self friction resistance is, the shorter the shutdown time is. The rear end of the engine is generally provided with a flywheel, the flywheel has certain rotational inertia in the rotating process, the rotational inertia is related to the self weight of the flywheel and the rotating speed of the flywheel, and the heavier the flywheel is, the higher the rotating speed is, the larger the rotational inertia is generated by the flywheel. Through a large number of practices, the rotation of the flywheel still drives the engine to complete four work cycles of air suction, compression, work application and exhaust in the rear section (namely about 150r/min-0r/min) of flameout rotation speed reduction of the engine, in the work application process, although the engine does not inject oil, compressed high-pressure gas still applies work to a piston to generate thrust, the more fresh air is sucked in the air suction process, the greater expansion power is generated in the work application process, the greater the expansion power is, the greater the impact is generated in the flameout process, and the phenomena of vibration, shaking or resonance are generated in the flameout and shutdown processes of the engine and the whole vehicle, so that the comfort is influenced.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

The invention aims to provide a control system and a control method for reducing engine flameout process jitter through exhaust throttle valve control, which have simple and reasonable structure.

To achieve the above object, the present invention provides a control system for reducing engine stall jitter through exhaust throttle control, comprising: the exhaust end of the engine is sequentially provided with an engine exhaust manifold and an engine exhaust main pipe; an exhaust throttle valve provided on the engine exhaust manifold; and the electronic control unit is in control connection with the exhaust throttle valve, and automatically identifies the flameout working condition of the engine, so as to send a control command to the exhaust throttle valve to close the exhaust throttle valve.

In a preferred embodiment, the exhaust end of the engine exhaust manifold is provided with an exhaust muffler or aftertreatment device.

The invention also provides a control method of the control system for controlling and reducing the shake of the engine in the flameout process through the exhaust throttle valve, which is characterized in that in the flameout and shutdown process, the electronic control unit automatically identifies the flameout working condition of the engine, so as to send a control command to the exhaust throttle valve to close the exhaust throttle valve, so that the engine can generate larger exhaust resistance in the flameout process to inhibit and consume the rotation energy of the engine flywheel, and further inhibit and absorb the shake generated by the flywheel in the flameout process.

In a preferred embodiment, the degree of closure of the exhaust throttle valve amounts to 90% to 100%.

Compared with the prior art, the control system and the control method for reducing the engine flameout process jitter through the control of the exhaust throttle valve have the following beneficial effects: according to the control system and the control method for reducing the engine flameout process shake through the exhaust throttle valve, in the flameout and shutdown process, the exhaust resistance is controlled through the closing degree of the exhaust throttle valve, the in-cylinder friction work is increased through the exhaust resistance to restrain and absorb the shake of the flywheel generated in the flameout process, the shake phenomenon of the whole vehicle is effectively reduced, and the driving comfort is improved.

Drawings

FIG. 1 is a schematic diagram of a control system for reducing engine misfire process judder through exhaust throttle control in accordance with a first embodiment of the present invention.

Detailed Description

The following detailed description of the present invention is provided in conjunction with the accompanying drawings, but it should be understood that the scope of the present invention is not limited to the specific embodiments.

Throughout the specification and claims, unless explicitly stated otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element or component but not the exclusion of any other element or component.

The shaking of the engine in the flameout process is caused by the rotational inertia effect of the flywheel, the resistance of the engine is unbalanced in the flameout low rotating speed section, the resistance at the moment is mainly derived from the compression pressure in the engine cylinder, the variation of the compression pressure in the cylinder is caused by the instability of the low speed of the engine, and even the phenomenon of back-dragging and reverse rotation is caused, which is the root cause of the shaking.

To solve the above problem, as shown in fig. 1, a control system for reducing the chattering of an engine stalling process by exhaust throttle control according to a preferred embodiment of the present invention has a specific structure including: an engine 1, an electronic control unit 7 and an exhaust throttle valve 5. In the process of engine flameout, the exhaust throttle valve 5 is arranged on an exhaust main pipe of the engine 1, the electronic control unit 7 can automatically identify the flameout working condition of the engine, and accordingly a control command is sent to the exhaust throttle valve, the throttle valve is closed at a large position, so that the exhaust resistance of the engine can be increased in the flameout process, resistance is generated due to exhaust closing in the flameout process of the engine, the resistance of gas is flexible, the large flexible exhaust resistance can inhibit, balance and absorb the flywheel change rotational inertia, the shaking phenomenon of the whole vehicle is effectively reduced, and the driving comfort is improved.

Specifically, an exhaust end of the engine 1 is provided with an engine exhaust manifold 3 and an engine exhaust manifold 4 in this order. An engine exhaust manifold 3 is connected to the engine block and collects exhaust gas from each cylinder and guides the collected exhaust gas to an engine exhaust manifold 4. The requirements for the engine exhaust manifold 3 are mainly to minimize exhaust resistance and to avoid mutual interference between cylinders. When the exhaust is excessively concentrated, mutual interference can be generated among cylinders, namely when a certain cylinder exhausts, the exhaust gas which is not exhausted and is emitted from other cylinders is just hit. This increases the resistance of the exhaust gas, thereby reducing the output of the engine. The solution is to divide the exhaust of the cylinders as much as possible, one branch for each cylinder, or one branch for both cylinders, and to lengthen and shape each branch as much as possible independently to reduce the mutual influence of the gases in the different pipes.

Preferably, the exhaust end of the engine exhaust manifold 4 is provided with an exhaust muffler or aftertreatment device 6.

The exhaust throttle valve 5 is arranged on an engine exhaust manifold 4, exhaust resistance is controlled through the closing degree of the exhaust throttle valve, and the shake generated by the flywheel in the flameout process is restrained and absorbed by increasing the in-cylinder friction work through the exhaust resistance.

The electronic control unit 7 is in control connection with the exhaust throttle valve 5, and the electronic control unit 7 automatically identifies the flameout working condition of the engine, so that a control instruction is sent to the exhaust throttle valve, the throttle valve is closed at a larger position, and therefore, the exhaust resistance can be increased in the flameout process of the engine, and the resistance is generated due to exhaust closing in the flameout process of the engine.

The control method for reducing the engine stalling process jitter through the exhaust throttle valve control according to the preferred embodiment of the invention specifically comprises the following steps: the electronic control unit can flexibly control the closing degree of the exhaust throttle valve according to different running conditions of the engine, when the throttle valve is fully opened (0% closing degree), the exhaust resistance is minimum, and when the exhaust throttle valve is fully closed (100% closing degree), the exhaust resistance is maximum. When the engine is in a flameout process, the electronic control unit can automatically recognize the flameout working condition of the engine, so that a control command is sent to the exhaust throttle valve, the exhaust throttle valve is closed at a larger position (the closing degree is generally 90% -100%), the engine can generate larger exhaust resistance to inhibit and consume the rotation energy of the flywheel of the engine in the flameout process, and the rotation inertia of the flywheel is flexibly eliminated in the flameout process because the resistance generated by gas is flexible, and the phenomena of shaking and reversion cannot be generated.

In conclusion, the control system and the control method for reducing the engine flameout process jitter through the exhaust throttle valve control have the advantages that in the flameout and shutdown process, the exhaust resistance is controlled through the closing degree of the exhaust throttle valve, the in-cylinder friction work is increased through the exhaust resistance to restrain and absorb the jitter generated in the flameout process of the flywheel, the jitter phenomenon of the whole vehicle is effectively reduced, and the driving comfort is improved.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application to enable one skilled in the art to make and use various exemplary embodiments of the invention and various alternatives and modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalents.