阅读说明：本技术 熄火抖动改善方法 (Flameout jitter improvement method ) 是由 庄兵 黄晓攀 翁乙文 于 2018-06-28 设计创作，主要内容包括：本发明提供了一种熄火抖动改善方法,所述熄火抖动改善方法包括：发动机控制单元接收到熄火信号,进入发动机熄火过程；所述发动机控制单元发出控制信号继续控制流量控制阀开启；凸轮轴转动驱动高压油泵工作；在所述发动机熄火过程中的瞬时转速波动上升阶段,将所述流量控制阀的泵油持续角调到最大,减小发动机转速波动。本发明所提供的方法,利用了高压油泵由凸轮轴驱动,而反过来高压油泵在工作时会给凸轮轴施加一定的阻力,进而在所述发动机熄火过程中的转速瞬时转速波动上升阶段,将所述流量控制阀的泵油持续角调到最大,使得高压油泵对凸轮轴的阻力最大,从而能在最大程度上的减少熄火过程中发动机转速的峰值震荡,从而减少熄火过程中的振动,缩短熄火时间。(The invention provides a flameout jitter improvement method, which comprises the following steps: the engine control unit receives the flameout signal and enters the flameout process of the engine; the engine control unit sends out a control signal to continuously control the flow control valve to be opened; the camshaft rotates to drive the high-pressure oil pump to work; and in the transient rotating speed fluctuation rising stage in the flameout process of the engine, the continuous oil pumping angle of the flow control valve is adjusted to be maximum, and the rotating speed fluctuation of the engine is reduced. According to the method provided by the invention, the high-pressure oil pump is driven by the camshaft, and certain resistance is applied to the camshaft when the high-pressure oil pump works in turn, so that the oil pumping continuous angle of the flow control valve is adjusted to be maximum at the stage of the instantaneous fluctuation rise of the rotating speed in the flameout process of the engine, the resistance of the high-pressure oil pump to the camshaft is maximum, the peak value oscillation of the rotating speed of the engine in the flameout process can be reduced to the maximum extent, the vibration in the flameout process is reduced, and the flameout time is shortened.)

1. A misfire judder improving method comprising the steps of:

the engine control unit receives the flameout signal and enters the flameout process of the engine;

the engine control unit sends out a control signal to continuously control the flow control valve to be opened;

the camshaft rotates to drive the high-pressure oil pump to work; and

and in the transient rotating speed fluctuation rising stage in the flameout process of the engine, the continuous oil pumping angle of the flow control valve is adjusted to be maximum, and the rotating speed fluctuation of the engine is reduced.

2. The misfire judder improving method as recited in claim 1, wherein the pump oil continuation angle of the flow control valve is adjusted to the maximum in a region where the engine speed rises from top dead center to a peak and a stroke of the high pressure oil pump for supplying oil coincide.

3. The method of flameout judder improvement as claimed in claim 1, wherein said high pressure oil pump comprises a low pressure gasoline inlet, a low pressure oil rail, a flow control valve, a check valve, a plunger chamber, a plunger, a high pressure oil rail, and a high pressure gasoline outlet;

the low-pressure gasoline inlet is connected with one end of the flow control valve through the low-pressure oil rail, the other end of the flow control valve is connected with one end of the plunger cavity, the other end of the plunger cavity is connected with one end of the plunger in a sleeved mode, the other end of the plunger is connected with one end of the cam shaft, one end of the plunger cavity is connected with one end of the one-way valve, the other end of the one-way valve is connected with one end of the high-pressure oil rail, and the other end of the high-pressure oil rail is connected with the high-pressure gasoline outlet.

4. A misfire shake improving method as recited in claim 2 or 3, wherein a rail pressure sensor is provided at the high pressure gasoline outlet, the camshaft rotationally drives the high pressure oil pump to operate, the rail pressure sensor detects a pressure at the high pressure gasoline outlet and transmits a rail pressure signal to the engine control unit, and the engine control unit adjusts a pump oil continuation angle of the flow control valve in accordance with the rail pressure signal.

5. The method of improving flameout judder as claimed in claim 3, wherein rotation of said camshaft drives said plunger in a reciprocating motion, pressing the low pressure oil in said low pressure oil rail into said high pressure oil rail.

6. A method of flameout judder improvement as claimed in claim 3 wherein said plunger travels downward, said flow control valve opens, said check valve closes, and said plunger draws low pressure oil into said plunger chamber.

7. The method of improving flameout judder as claimed in claim 3, wherein said plunger moves upward, said flow control valve is closed, said check valve is opened, and high-pressure oil in said plunger chamber is forced into said high-pressure oil rail and discharged.

8. The misfire shake improving method as recited in claim 1, wherein the oil pumping duration angle of the flow control valve is made maximum in a transient rotational speed fluctuation rising phase during the engine misfire, and the high-pressure oil pump applies resistance to the camshaft to reduce the rotational speed fluctuation of the camshaft.

9. The method for improving flameout judder as claimed in claim 8, wherein the resistance torque generated after the resistance is applied is in a range of 3 Nm to 5 Nm.

10. The flameout judder improvement method as claimed in claim 1, wherein the oil pumping duration angle of the flow control valve is maximized to provide 6 Nm to 8Nm peak torque.

11. The misfire chattering improving method as recited in claim 1, wherein a pumping continuation angle of said flow control valve is 120 degrees at maximum.

Technical Field

The invention relates to the field of automobile electronic manufacturing, in particular to a flameout jitter improving method.

Background

The cylinders of the three-cylinder engine and the four-cylinder engine are arranged in a line, because the ignition sequence of the three cylinders in the three-cylinder engine can only be 123 to ignite in sequence, the piston is easy to form rhythm in the power stroke, and the ignition sequence of the four-cylinder engine is generally 1342, namely after the 1 st cylinder does work, the 3 rd cylinder does work, the 4 th cylinder does work and the 2 nd cylinder does work, thus, each cylinder can play a role in counteracting the vibration of the previous cylinder when doing work, the whole vibration of the engine is small, if the engine is a six-cylinder in-line engine, the ignition sequence is generally 142635 or 153624, and the ignition work sequence of each cylinder is designed in this way, so that the vibration of the engine is reduced. Therefore, it is theorized that the order of work done by the firing of the cylinders determines that three cylinders are experiencing more jerk than four cylinders.

Compared with a four-cylinder machine, the three-cylinder machine has the advantages that the pumping frequency of the cam per revolution is reduced by 1 time, and the corresponding pumping loss and friction loss are reduced, so the resistance is small; in addition, under the same resonance frequency, the three-cylinder machine can achieve resonance only at a higher rotation speed because the cam does less work once per week, and the resonance rotation speed is high. The three-cylinder machine has small resistance and high resonance rotating speed relative to the four-cylinder machine, so that the flameout process time of the three-cylinder machine relative to the four-cylinder machine is prolonged, and the vibration is increased. Especially for a three-cylinder machine provided with a dual-mass flywheel, the resonance point is low, flameout jitter is obvious, the comfort of the flameout process of the vehicle is influenced to a great extent, and the problem to be solved is urgent.

Disclosure of Invention

The invention aims to provide a flameout shake improving method to solve the problem that a three-cylinder machine is easy to vibrate in a flameout process due to the characteristic of unsmooth operation.

In order to achieve the above object, the present invention provides a flameout judder improving method, comprising the steps of:

the engine control unit receives the flameout signal and enters the flameout process of the engine;

the engine control unit sends out a control signal to continuously control the flow control valve to be opened;

the camshaft rotates to drive the high-pressure oil pump to work;

and in the transient rotating speed fluctuation rising stage in the flameout process of the engine, the continuous oil pumping angle of the flow control valve is adjusted to be maximum, and the rotating speed fluctuation of the engine is reduced.

Alternatively, the oil pumping duration angle of the flow control valve is adjusted to the maximum in the region where the engine speed rises from top dead center to the peak and the stroke of the high-pressure oil pump for oil supply coincide with each other.

Optionally, the method for improving flameout shake is implemented by a flameout shake control system, wherein the flameout shake control system comprises an engine control unit, a high-pressure oil pump, a camshaft and a rail pressure sensor;

the high-pressure oil pump comprises a low-pressure gasoline inlet, a low-pressure oil rail, a flow control valve, a one-way valve, a plunger cavity, a plunger, a high-pressure oil rail and a high-pressure gasoline outlet;

the low-pressure gasoline inlet is connected with one end of the flow control valve through the low-pressure oil rail, the other end of the flow control valve is connected with one end of the plunger cavity, the other end of the plunger cavity is connected with one end of the plunger in a sleeved mode, the other end of the plunger is connected with one end of the cam shaft, one end of the plunger cavity is connected with one end of the one-way valve, the other end of the one-way valve is connected with one end of the high-pressure oil rail, and the other end of the high-pressure oil rail is connected with the high-pressure gasoline outlet.

Optionally, a rail pressure sensor is arranged at the high-pressure gasoline outlet, the camshaft drives the high-pressure oil pump to work in a rotating manner, the rail pressure sensor detects the pressure of the high-pressure gasoline outlet and transmits a rail pressure signal to the engine control unit, and the engine control unit adjusts the oil pumping continuation angle of the flow control valve according to the rail pressure signal.

Optionally, the camshaft rotates to drive the plunger to reciprocate, and the low-pressure oil in the low-pressure oil rail is pressed into the high-pressure oil rail.

Optionally, the plunger moves downward, the flow control valve is opened, the check valve is closed, and the plunger sucks low-pressure oil into the plunger cavity.

Optionally, the plunger moves upwards, the flow control valve is closed, the check valve is opened, and the high-pressure oil in the plunger cavity is pressed into the high-pressure oil rail to be discharged.

Optionally, in an instantaneous rotation speed fluctuation rising stage in the engine stalling process, the oil pumping duration angle of the flow control valve is adjusted to be maximum, and the high-pressure oil pump applies resistance to the camshaft to reduce rotation speed fluctuation of the camshaft.

Optionally, the range of the resistance moment generated after the resistance is applied is 3-5 Nm.

Optionally, the continuous angle of pumping of the flow control valve is adjusted to a maximum to provide 6-8 Nm peak torque.

Optionally, the oil pumping duration angle of the flow control valve is at most 120 crank angle degrees.

As described above, in the misfire-chattering improvement method provided by the present invention, the misfire-chattering improvement method includes: the engine control unit receives the flameout signal and enters the flameout process of the engine; the engine control unit sends out a control signal to continuously control the flow control valve to be opened; the camshaft rotates to drive the high-pressure oil pump to work; and in the transient rotating speed fluctuation rising stage in the flameout process of the engine, the continuous oil pumping angle of the flow control valve is adjusted to be maximum, and the rotating speed fluctuation of the engine is reduced. The method provided by the invention utilizes the fact that the high-pressure oil pump is driven by the camshaft, and in turn, the high-pressure oil pump can apply certain resistance to the camshaft when in work, so that the oil pumping continuous angle of the flow control valve is adjusted to be maximum at the stage of the instantaneous fluctuation of the rotating speed during the flameout process of the engine, and the resistance of the high-pressure oil pump to the camshaft is maximum, thereby reducing the peak value oscillation of the rotating speed of the engine during the flameout process to the maximum extent, reducing the vibration during the flameout process and shortening the flameout time.

Drawings

FIG. 1 is a flowchart illustrating a method for improving flameout jitter according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a flameout jitter control system according to an embodiment of the present invention;

FIG. 3 is a waveform diagram of the engine speed and the pumping stroke of the high-pressure oil pump according to the embodiment of the invention;

FIG. 4 is a comparison graph of an engine transient rotational speed waveform and an original transient rotational speed waveform based on rail pressure control, provided by an embodiment of the present invention;

FIG. 5 is a graph illustrating a comparison of an engine transient rotational speed waveform and an original transient rotational speed waveform based on rail pressure control according to an embodiment of the present invention;

wherein, 11-a high-pressure oil pump; 110-low pressure gasoline inlet; 111-low pressure oil rail; 112-a flow control valve; 113-a plunger; 114-a one-way valve; 115-a plunger cavity; 116-high pressure oil rail; 117-high pressure gasoline outlet; 12-a rail pressure sensor; 13-a camshaft; 14-an engine control unit; 21-oil pumping stroke of the high-pressure oil pump; 22-engine instantaneous speed.

Detailed Description

The following describes in more detail embodiments of the present invention with reference to the schematic drawings. Advantages and features of the present invention will become apparent from the following description and claims. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.

As described in the background art, the cylinders of the three-cylinder engine are arranged in a line, the ignition sequence of the three cylinders in the three-cylinder engine can only be 123, the pistons are easy to form rhythm in the power stroke, the ignition power sequence of the cylinders determines that the three cylinders are more shaken than the four cylinders, the three-cylinder engine is easy to vibrate (rotate speed fluctuation) in the flameout process due to the characteristic of unsmooth operation, particularly for the three-cylinder engine provided with the dual-mass flywheel, the resonance point is lower, the flameout shaking is particularly obvious, and the comfort of the flameout process of the vehicle is greatly influenced.

Therefore, in order to solve the above problems in the manufacture of automotive electronics, the present invention provides a flameout judder improving method.

Referring to fig. 1, fig. 1 is a schematic flow chart of a flameout jitter improvement method provided by the present invention, as shown in fig. 2, the flameout jitter improvement method includes the following steps:

step S1: the engine control unit receives the flameout signal and enters the flameout process of the engine;

step S2: the engine control unit sends out a control signal to continuously control the flow control valve to be opened;

step S3: the camshaft rotates to drive the high-pressure oil pump to work;

step S4: and in the transient rotating speed fluctuation rising stage in the flameout process of the engine, the continuous oil pumping angle of the flow control valve is adjusted to be maximum, and the rotating speed fluctuation of the engine is reduced.

Further, a flameout judder control system is provided, specifically, referring to fig. 2, fig. 2 is a schematic diagram of the flameout judder control system according to the embodiment of the present invention, as shown in fig. 2, the flameout judder control system includes an engine control unit 14(ECU), a camshaft 13, a high-pressure oil pump 11 and a rail pressure sensor 12; the high-pressure oil pump 11 comprises a low-pressure gasoline inlet 110, a low-pressure oil rail 111, a flow control valve 112, a one-way valve 114, a plunger cavity 115, a plunger 113, a high-pressure oil rail 116 and a high-pressure gasoline outlet 118; the low-pressure gasoline inlet 110 is connected with one end of the flow control valve 112 through the low-pressure oil rail 111, the other end of the flow control valve 112 is connected with one end of the plunger cavity 115 (the flow control valve is connected with the plunger cavity through an internal connection structure in fig. 2), the other end of the plunger cavity 115 is sleeved with one end of the plunger 113, the other end of the plunger 113 is connected with one end of the camshaft 13, the other end of the plunger cavity 115 is connected with one end of the check valve 114, the other end of the check valve 114 is connected with one end of the high-pressure oil rail 116, and the other end of the high-pressure oil rail 116 is connected with the high-pressure gasoline outlet 117.

Specifically, in step S3, when the engine is running normally, the camshaft 13 rotates to drive the plunger 113 of the high-pressure oil pump 11(HDP) to reciprocate, and when the plunger 113 moves downward, the flow control valve 112 is in an open state, the check valve 114 is closed, and the plunger 113 sucks low-pressure oil into the plunger cavity 115; when the plunger 113 moves upward, the flow control valve 112 is closed, the check valve 114 is opened, the high-pressure oil in the plunger cavity 115 is pressed into the high-pressure oil rail 116, and the high-pressure oil flows to the high-pressure gasoline outlet 117 through the high-pressure oil rail 116 and then is discharged.

In step S4, the oil pumping duration angle of the flow control valve is adjusted to be maximum in the overlapping area of the process of the engine speed rising from the top dead center to the peak value and the stroke of the high-pressure oil pump, further, a rail pressure sensor is arranged at the high-pressure oil outlet, the camshaft rotationally drives the high-pressure oil pump to work, the rail pressure sensor detects the pressure of the high-pressure oil outlet and transmits a rail pressure signal to the engine control unit, and the engine control unit adjusts the oil pumping duration angle of the flow control valve according to the rail pressure signal. Specifically, the flow control valve 112 (MSV valve for short) controls the amount of low-pressure oil entering the high-pressure oil, the engine control unit 14(ECU) may control the oil pumping duration angle of the flow control valve 112 according to the magnitude of the target engine pressure, the high-pressure oil outlet pressure may be actually measured by the rail pressure sensor 12, the rail pressure sensor 12 transmits the measured rail pressure signal to the engine control unit 14(ECU), and the engine control unit 14 controls the flow control valve 112 according to the received rail pressure signal, so as to form a closed-loop control.

The rotating speed of the engine is generally lower in an idling stage, rail pressure (namely pressure of a high-pressure oil outlet) is also lower, after an Engine Control Unit (ECU) 14 receives a flameout signal, a control signal is sent out to continuously control the flow control valve to be opened, meanwhile, the continuous angle of pump oil of the flow control valve can be adjusted to be the largest, the flow of low-pressure oil flowing out is increased, the driving force required by reciprocating motion of a plunger is increased when the flow of the low-pressure oil is increased, and therefore higher pressure is built in the high-pressure oil outlet, and the increased pressure of the high-pressure oil outlet indicates that the resistance of the plunger motion of the high-pressure oil pump to the rotation of a camshaft is increased, so that the resistance to the rotation of. Further, for a direct injection engine, the high-pressure oil pump is driven by the camshaft, and meanwhile, a certain resistance is applied to the camshaft when the high-pressure oil pump works, so that the maximum resistance moment can be generated under a certain flow of low-pressure oil, and specifically, the maximum resistance moment can be generated to be 3-5 Nm; the resistance moment enables the rotating speed of the camshaft to be reduced, the rotating speed of the camshaft is half of the rotating speed of the crankshaft because the crankshaft controls the rotation of the engine, when the rotating speed of the camshaft is reduced, the rotating speed of the engine is reduced, and flameout and shaking of the engine can be improved by means of the resistance moment.

In one embodiment, the engine is a three cylinder engine, and typically the number of lobes is the same as the number of cylinders, so that for a three cylinder engine the maximum pumping is 120 crank angle degrees. Specifically, the peak value of the instantaneous engine speed occurs between the Top Dead Center (TDC) and the Bottom Dead Center (BDC) and is biased towards the Bottom Dead Center (BDC), and the instantaneous engine speed 22 and the oil supply stroke 21 of the high-pressure oil pump are represented by the waveform diagram, as shown in fig. 3, the process of the instantaneous engine speed 22 of the three-cylinder engine rising from the TDC0 to the peak value and the oil supply stroke 21 of the high-pressure oil pump have a coincidence region. By utilizing the discovery, if the pumping oil continuous angle of the flow control valve of the high-pressure oil pump is adjusted to be maximum in the process of increasing the engine rotating speed in the process of flameout of the engine, so that the high-pressure oil pump works in full load, the low-pressure oil quantity pressed into the high-pressure oil rail by the plunger is maximum at this time, the plunger of the high-pressure oil pump needs to provide larger driving force for the camshaft when reciprocating, and meanwhile, the high-pressure oil pump has maximum resistance to the camshaft, so that the rotating speed of the camshaft is slowed, the rotating speed of the crankshaft is slowed, and meanwhile, a higher pressure is established at the high-pressure oil outlet of the high-pressure oil pump, so that the oscillation peak value of the engine rotating speed in the process of flameout can be reduced to the maximum. Specifically, the maximum oil pumping duration angle is 120 crank angle degrees; whether the instantaneous rotation speed fluctuation of the engine is in a rising stage or not can be detected through a sensor when the engine is flamed out, if the rail pressure detected by a rail pressure sensor is smaller, the instantaneous rotation speed fluctuation of the engine is in the rising stage, the resistance generated by a high-pressure oil pump to the rotation of a cam shaft when the high-pressure oil pump works is small, the generated rail pressure is smaller, a detected rail pressure signal is sent to an Engine Control Unit (ECU), the Engine Control Unit (ECU) sends a control signal to adjust the continuous angle of oil pumping of a flow control valve to the maximum, and the resistance generated by the high-pressure oil pump to the rotation of the cam shaft when the high-; theoretically, the maximum resistance torque is 3-5 Nm, and the peak torque of the engine rotating speed is 6-8 Nm.

Referring to fig. 4 and 5, fig. 4 and 5 are graphs comparing an instantaneous rotational speed waveform of an engine with an original instantaneous rotational speed waveform using the method of the present invention, fig. 4 shows a waveform of an original instantaneous rotational speed of the engine based on original rail pressure control, an oil pumping continuation angle, a rail pressure waveform during shutdown, and an instantaneous rotational speed waveform of the engine based on rail pressure control, and one oil pumping process corresponds to a peak of the instantaneous rotational speed of the engine, and it can be seen from fig. 4 that the oil pumping continuation angle of a flow control valve of a high pressure oil pump is adjusted to be maximum using the method of the present invention, and the peak of the instantaneous rotational speed of the engine is reduced when oil is pumped. The oil pumping duration angle, the rail pressure waveform during the stop, the original transient rotational speed waveform of the engine and the rotational speed waveform based on the rail pressure control are shown in fig. 5, and it can be seen from fig. 5 that the engine based on the rail pressure control is stopped before the original engine, and the stop time is shortened by more than 100 ms.

As described above, in the misfire-chattering improvement method provided by the present invention, the misfire-chattering improvement method includes: the engine control unit receives the flameout signal and enters the flameout process of the engine; the engine control unit sends out a control signal to continuously control the flow control valve to be opened; the camshaft rotates to drive the high-pressure oil pump to work; and in the transient rotating speed fluctuation rising stage in the flameout process of the engine, the continuous oil pumping angle of the flow control valve is adjusted to be maximum, and the rotating speed fluctuation of the engine is reduced. The method provided by the invention utilizes the fact that the high-pressure oil pump is driven by the camshaft, and conversely, the high-pressure oil pump can apply certain resistance to the camshaft when in work, the oil pumping continuous angle of the flow control valve of the high-pressure oil pump is adjusted to be maximum at the stage of instantaneous fluctuation rise of the rotating speed in the flameout process of an engine, so that the high-pressure oil pump works under full load, the low-pressure oil quantity pressed into the high-pressure oil rail by the plunger is maximum, the plunger of the high-pressure oil pump needs to provide larger driving force for the camshaft when in reciprocating motion, simultaneously, the resistance of the high-pressure oil pump to the camshaft is maximum, the maximum resistance moment is generated, the rotating speed of the camshaft is slowed down, further, the rotating speed of a crankshaft is slowed down, and the high-pressure oil outlet of the high-pressure oil pump establishes larger pressure, so that the, the flameout time is shortened.

The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any way. It will be understood by those skilled in the art that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.