CN114562373A

CN114562373A - Control method for engine flameout vibration reduction

Info

Publication number: CN114562373A
Application number: CN202210069559.4A
Authority: CN
Inventors: 张桂军; 雷雪; 马也驰; 贾江涛; 罗丹
Original assignee: Dongfeng Motor Corp
Current assignee: Dongfeng Motor Corp
Priority date: 2022-01-21
Filing date: 2022-01-21
Publication date: 2022-05-31

Abstract

The invention discloses a method for controlling flameout and vibration reduction of an engine, which comprises the following steps of: s1, judging whether the engine has a flameout request or not when the vehicle is in an idling working condition, and if so, reducing the torque and reducing the fuel injection quantity and the air inflow; s2, reducing the rotating speed of the engine along with the reduction of the oil injection quantity and the air intake quantity; and S3, when the engine speed is reduced to a first threshold value and the pressure of the intake manifold is reduced to a second threshold value, the automobile engine eliminates flameout vibration, and the throttle opening is closed. The invention can reduce the flameout vibration of the automobile engine and avoid the NVH problem.

Description

Control method for engine flameout vibration reduction

Technical Field

The invention belongs to the field of engine control, and particularly relates to a control method for engine flameout and vibration reduction

Background

When the ignition key of an engine in a vehicle is turned off, the target torque value and the fuel injection amount of the engine are set to zero at respective timings, so that the fuel supply to all cylinders of the engine is successively stopped. However, unlike the fuel injection amount or the target torque value, the value of the Revolutions Per Minute (RPM) of the engine does not immediately become 0 at the time of key-off, but gradually decreases with time. This is because the piston in the cylinder of the engine keeps moving inertially for a predetermined time despite the fuel supply being stopped. There is a problem in that engine vibration is caused due to such piston movement, and when the engine vibration becomes large, the vehicle body vibrates violently to generate noise.

Disclosure of Invention

The invention aims to provide a control method for engine stall vibration reduction, which can reduce the engine stall vibration of an automobile and avoid the NVH problem.

In order to solve the technical problems, the technical scheme of the invention is as follows: a method for controlling engine flameout damping comprises the following steps:

s1, judging whether the engine has a flameout request or not when the vehicle is in an idling working condition, and if so, reducing the torque and reducing the fuel injection quantity and the air inflow;

s2, reducing the rotating speed of the engine along with the reduction of the oil injection quantity and the air intake quantity;

and S3, when the engine speed is reduced to a first threshold value and the pressure of the intake manifold is reduced to a second threshold value, the automobile engine eliminates flameout vibration, and the opening degree of the throttle valve is closed.

When there is no power generation load, the method further comprises the following steps:

and S4, stopping oil injection.

When there is a power generation load, S2 and S3 are specifically:

s2.1, reducing the rotating speed of the engine along with the reduction of the oil injection quantity and the air input quantity;

s2.2, closing a throttle valve, and reducing the pressure of an intake manifold;

s2.3, delaying to load the power generation torque;

and S3, when the rotating speed of the generator is reduced to a first threshold value and the pressure of the intake manifold is reduced to a second threshold value, the power generation torque is rapidly loaded to enable the automobile engine to eliminate flameout vibration.

At S2, the intake air amount is reduced by reducing the throttle opening.

The first threshold is 300 revolutions.

The second threshold is 30 kpa.

There is also provided a computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the steps of the method as claimed in any one of the above when executing the computer program.

There is also provided a computer readable storage medium having stored thereon a computer program which, when executed by a processor, carries out the steps of the method of any one of the above.

Compared with the prior art, the invention has the beneficial effects that:

the flameout vibration of the automobile engine can be reduced, and the NVH problem can be avoided.

Drawings

FIG. 1 is a schematic flow chart of an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the respective embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

As shown in fig. 1, the present invention is directed to a control method for controlling fuel cut by controlling intake manifold pressure through actual engine speed and throttle opening during an engine stall phase (when there is no power generation load), and finally achieving reduction of vehicle engine stall vibration and avoidance of NVH problem. In the engine stalling stage, the pressure of an intake manifold is controlled by the opening of a throttle valve and the rapid loading of the generating torque after the delaying of the loading of the generating torque, and finally the control method for reducing the stalling vibration of the automobile engine and avoiding the NVH problem is achieved.

The idling condition is stopped, and no power generation load exists.

Firstly, judging whether the engine has a flameout request or not, if so, reducing the fuel injection and the air intake amount according to the reduction of the required torque.

In the second step, the engine speed is decreased as the intake air amount is decreased (the throttle opening is made smaller) and as the fuel injection amount is decreased.

Third, the speed drops below the first threshold (300 revolutions) and the intake manifold pressure drops below the second threshold (30kpa), and the throttle is fully closed (high speed closes the throttle, cylinder negative pressure can cause combustion of oil, resulting in PN being too high)

Fourthly, stopping oil injection

The idling stop is stopped and has a power generation load.

In the second step, the engine speed is reduced as the intake air amount is reduced (the throttle opening degree becomes smaller) and as the fuel injection amount is reduced.

Third, the throttle is closed and the pressure in the intake manifold decreases as the throttle closes.

And fourthly, delaying the loading of the generating torque.

Fifth, when the pressure in the intake manifold drops to a second threshold (30kpa), the electric power generation torque is rapidly applied to ensure that the manifold pressure drops to the NVH OK region.

In the NVH OK state, the opening degree of a flameout throttle valve is 0%, in this case, although no vibration problem exists, the negative pressure of a cylinder occurs, the phenomenon of burning oil is caused, and PN is overhigh.

In NVH NG state: in the case where the cut-off throttle opening degree is 5% (it is not completely closed all the time), vibration occurs.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A method for controlling engine flameout damping is characterized by comprising the following steps:

and S3, when the engine speed is reduced to a first threshold value and the pressure of the intake manifold is reduced to a second threshold value, the automobile engine eliminates flameout vibration, and the throttle opening is closed.

2. The method of controlling engine stall damping according to claim 1, further comprising the step of, when there is no power generation load:

and S4, stopping oil injection.

3. The method for controlling engine stall damping according to claim 1, wherein when there is a power generation load, S2 and S3 are specifically:

s2.3, delaying the loading of the generating torque;

4. The method of controlling engine misfire damping as recited in claim 1 wherein the amount of intake air is decreased by decreasing the throttle opening in S2.

5. The method of controlling engine misfire damping as recited in claim 1, wherein the first threshold is 300 revolutions.

6. The method of controlling engine misfire damping as recited in claim 1 wherein the second threshold is 30 kpa.

7. A computer arrangement comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the steps of the method according to any of claims 1-6 are implemented when the computer program is executed by the processor.

8. A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to any one of claims 1 to 6.