JPH0537018Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an acceleration shock prevention device using ignition timing control for an internal combustion engine for an automobile.

<Prior Art> In conventional internal combustion engines for automobiles, especially internal combustion engines equipped with electronically controlled fuel injection devices, fuel injection control is performed with good responsiveness depending on the engine operating state, so the throttle valve is not activated during acceleration operation. The combustion pressure (indicated mean effective pressure) follows changes in the opening degree with good responsiveness.

However, when the acceleration is finished and the vehicle enters a steady state, jerky vibrations occur due to vehicle rolling (variations in vehicle longitudinal G), and engine rotational fluctuations occur, resulting in poor drivability and ride comfort.

Therefore, as seen in Japanese Patent Application Laid-open No. 61-85580, for example, there is a system that corrects the ignition timing to the retarded side during acceleration to alleviate the acceleration shock.

<Problems to be solved by the invention> However, since correcting the ignition timing to the retarded side suppresses the output, a decrease in acceleration response is unavoidable.

In view of these points, it is an object of the present invention to make it possible to reduce the rolling of the vehicle without impairing the acceleration response.

<Means for Solving the Problems> Therefore, as shown in FIG. an acceleration fluctuation amount detection means for detecting a fluctuation amount of the opening (opening degree) every predetermined time; an acceleration fluctuation maximum value detection means for detecting a maximum value of the fluctuation amount after acceleration determination by the acceleration determination means; an acceleration fluctuation amount change detection means for detecting that the fluctuation amount becomes equal to or less than a predetermined value after the acceleration determination by the means, and emitting a detection signal; and an ignition device for receiving the detection signal after the acceleration determination by the acceleration determination means. An ignition timing advance means for correcting the ignition timing to the advance side by an amount corresponding to the maximum value of the fluctuation amount is provided.

<Operation> In the above configuration, when the engine shifts from an accelerating state to a steady state and the sudden increase in torque disappears, causing a sway, the state immediately before this sway changes to the amount of variation in the parameter that fluctuates during acceleration. It is detected that the value is below a predetermined value, and at this time, the ignition timing is corrected to the advanced side. This results in
Sudden torque changes are suppressed and oscillation is alleviated. In addition, the maximum value of the amount of variation in the above parameters during acceleration is detected, and the amount and ignition timing are corrected to the advanced side accordingly, so corrections are made in accordance with the expected magnitude of oscillation. Ru.

<Example> Examples of the present invention will be described below.

Referring to FIG. 2, air is taken into the engine 1 via an air cleaner 2, an intake duct 3, a throttle chamber 4, and an intake manifold 5.

An air flow meter 6 is provided in the intake duct 3 to detect the intake air flow rate. The throttle chamber 4 is provided with a throttle valve 7 that operates in conjunction with an accelerator pedal (not shown) to control the flow rate of intake air. A potentiometer-type throttle sensor 8 is attached to the throttle valve 7 to detect the throttle valve opening. The intake manifold 5 is provided with an electromagnetic fuel injection valve 9 for each cylinder, which injects fuel into the engine 1 that is pressure-fed from a fuel pump (not shown) and controlled to a predetermined pressure by a pressure regulator. .

The control unit 2 controls the fuel injection amount.
In the microcomputer built into 0,
The basic fuel injection amount is calculated from the intake air flow rate Q detected by the air flow meter 6 and the engine speed N calculated based on the signal from the crank angle sensor 10 built into the distributor 13, which will be described later.
Calculate Tp=K・Q/N (K is a constant), correct this as appropriate, and fuel injection amount Ti=Tp・COEF+Ts
(COEF is various correction coefficients including acceleration correction coefficient etc.
Ts is a voltage correction amount), and a drive pulse signal with a pulse width corresponding to this is applied to the fuel injection valve 9 at a predetermined timing in synchronization with the rotation of the engine 1.

Each cylinder of the engine 1 is provided with an ignition plug 11, and a high voltage generated by an ignition coil 12 is sequentially applied to these via a distributor 13, thereby igniting a spark to ignite and burn the air-fuel mixture. let Here, the timing of high voltage generation of the ignition coil 12 is controlled via a power transistor 12a attached thereto. Therefore, the ignition timing is controlled by controlling the on/off timing of the power transistor 12a using an ignition signal from the control unit 20.

To control this ignition timing, the engine speed N calculated based on the signal from the crank angle sensor 10 and the basic fuel injection amount Tp calculated as described above are used as engine operating state parameters. . Further, the throttle valve opening TVO detected based on the signal from the throttle sensor 7 is used.

Here, in the CPU of the microcomputer in the control unit 20, the third
Perform calculations according to the flowchart shown in the figure to control ignition timing (ignition advance angle) ADV.

In step 1 (denoted as S1 in the figure, the same applies hereinafter), the previous engine speed Nold is subtracted from the current engine speed N to calculate the amount of variation ΔN in the engine speed. In this embodiment, the engine speed is used as a parameter that changes during acceleration, and this portion corresponds to the acceleration fluctuation amount detection means.

In step 2, the acceleration determination flag F is determined, and if the acceleration determination flag F is 0 (acceleration determination has not been performed yet), the process proceeds to step 3.

In step 3, the current throttle valve opening
The amount of change ΔTVO in the throttle valve opening is calculated by subtracting the previous throttle valve opening TVO _pLd from TVO. Then, in step 4, the variation amount ΔTVO of the throttle valve opening is compared with the acceleration determination value C _acc . This part corresponds to the acceleration determining means.

Here, the amount of variation ΔTVO in the throttle valve opening is
If it is less than C _acc , the process proceeds to step 5, where the acceleration determination flag F is maintained at 0, and the maximum amount of variation in engine speed ΔN _nax is set to 0. Next, proceed to step 9 and set the control time DLTTIM and control number DLTCNT.
Set each to 0. Then, in the next step 10, the fourth job is executed as a background job.
According to the flowchart shown in the figure, the ignition advance angle map value MADV, which is determined by referring to the map from the engine speed N and the basic fuel injection amount Tp, is output as the final ignition advance angle ADV in the next step 11. . still,
The control time DLTTIM is a timer value automatically counted by a timer, and the control number DLTCNT is a count value counted up in step 15, which will be described later.

In the determination at step 4, if the variation amount ΔTVO of the throttle valve opening is greater than or equal to the acceleration determination value C _acc and it is determined that acceleration is occurring, the process proceeds to step 6 and the acceleration determination flag F is set to 1. After that, the process proceeds to step 7, where the amount of variation ΔN in engine speed is compared with the maximum value ΔN _nax of the amount of variation up to that point, and if ΔN>ΔN _nax , the current ΔN is changed to ΔN _nax in step 8. shall be. This portion corresponds to the acceleration variation maximum value detection means. Then, proceed to step 9 to set the control time
DLTTIM and control count DLTCNT are each 0.
Make it. Then, in step 10, the ignition advance angle map value MADV is set as the final ignition advance angle ADV, and in the next step 11, it is output.

After the acceleration judgment is made and the acceleration judgment flag F is set to 1, the process proceeds to step 12 based on the judgment made in step 2, and the engine speed fluctuation amount ΔN becomes equal to or less than the control start judgment value C _nio (approximately 0). Determine whether or not. This portion corresponds to the acceleration fluctuation amount change detection means.

If ΔN>C _nio , the engine is accelerating, so proceed from step 12 to step 7, compare the amount of change in engine speed ΔN with the maximum amount of variation up to that point, ΔN _nax , and if ΔN>ΔN _nax In step 8, the current ΔN is set to ΔN _nax . Then, the process proceeds to step 9, where the control time DLTTIM and the control number DLTCNT are each set to 0. Then, in step 10, the ignition advance angle map value MADV is set as the final ignition advance angle, and
Output in the next step 11.

If ΔN≦C _nio , the acceleration has ended and the vehicle is about to roll over, so the process proceeds from step 12 to step 13 and onwards, and the predetermined number of times B is controlled within the predetermined control time A. , correct the ignition timing to the advance side.

In other words, the control time is
If DLTTIM is less than the predetermined time A and the number of controls DLTCNT is less than the predetermined number B as determined in step 14, the number of controls DLTCNT is incremented by 1 in step 15, and then the amount of variation in engine speed during acceleration is determined in step 16. The amount of correction ΔADV for advancing the ignition timing corresponding to the maximum value ΔN _nax is searched by referring to a map created in advance. Then, in the next step 17, the ignition advance angle map value MADV is determined by referring to the map from the engine speed N and the basic fuel injection amount Tp according to the flow chart shown in FIG. 4, which is executed as a background job. By adding the correction amount ΔADV to the value, the final ignition advance angle ADV is determined.
In this way, the ignition timing is corrected to the advanced side by the correction amount ΔADV. Then, output in step 11. Here, steps 16 and 17 correspond to ignition timing advancing means.

The predetermined control time A has elapsed or the predetermined control number B
If the process has been completed, the process proceeds from step 13 or 14 to step 18, where the acceleration determination flag F is set to 0, and after ΔN _nax is set to 0, the process proceeds to steps 9 to 11 to return to normal control.

With this control, as shown in FIG. 5, the conventional characteristic without correction is shown by a solid line, and the characteristic of this embodiment is shown by a broken line, after acceleration, the amount of fluctuation ΔN of the engine speed becomes almost 0, and the rolling motion of the vehicle is improved. From the previous state, the ignition timing is corrected to the advanced side in order to counteract the oscillation.
Sudden torque changes can be suppressed.

Next, another embodiment will be described according to the flowchart of FIG.

In step 21, the current throttle valve opening is
The previous throttle valve opening TVO _pLd is subtracted from TVO to calculate the throttle valve opening variation ΔTVO. In this embodiment, the throttle valve opening is used as a parameter that changes during acceleration, and this portion corresponds to the acceleration fluctuation amount detection means.

In step 22, it is determined whether the fluctuation amount ΔTVO of the throttle valve opening is positive or negative.

If ΔTVO is negative, it means that the vehicle is decelerating, so proceed to step 25, set the acceleration judgment flag F to 0, and set the maximum value of the variation amount of the throttle valve opening ΔTVO _nax .
Set to 0. Next, proceed to step 29 to set the control time
DLTTIM and control count DLTCNT are each 0.
Make it. Then, in the next step 30, the engine speed N and the basic fuel injection amount are determined according to the flowchart shown in Fig. 4, which is executed as a background job.
The map value MADV of the ignition advance angle determined by referring to the map from Tp is set as the final ignition advance angle ADV, and is output in the next step 31.

If ΔTVO is positive or 0, the process advances to step 23 and the acceleration determination flag F is determined. If the acceleration determination flag F is 0 (if no acceleration determination has been made yet), the process advances to step 24.

In step 24, the amount of variation ΔTVO in the throttle valve opening is compared with the acceleration determination value C _acc . This part corresponds to the acceleration determining means.

Here, the amount of variation ΔTVO in the throttle valve opening is
If it is less than C _acc , the process proceeds to step 25, where the acceleration determination flag F is maintained at 0, and the maximum value ΔTVO _nax of the variation amount of the throttle valve opening is set to 0. Next, proceed to step 29 to set the control time DLTTIM and control number.
Set DLTCNT to 0. Then, in step 30, the ignition advance angle map value MADV is set as the final ignition advance angle ADV, and in the next step 31, it is output.

If it is determined in step 24 that the amount of variation ΔTVO in the throttle valve opening is greater than or equal to the acceleration determination value C _acc and that acceleration is occurring, the process proceeds to step 26 and the acceleration determination flag F is set to 1. After that, proceed to step 27 and compare the amount of variation ΔTVO in the throttle valve opening with the maximum value ΔTVO _nax of the amount of variation up to that point.
If ΔTVO > ΔTVO _nax , in step 28 the current ΔTVO is set to ΔTVO _nax . This portion corresponds to the acceleration variation maximum value detection means. Then, proceed to step 29 to set the control time DLTTIM and control number.
Set DLTCNT to 0. Then, in step 30, the ignition advance angle map value MADV is set as the final ignition advance angle ADV, and in the next step 31, it is output.

After the acceleration judgment is made and the acceleration judgment flag F is set to 1, the process proceeds to step 32 based on the judgment made in step 23, and the throttle valve opening variation amount ΔTVO becomes equal to or less than the control start judgment value C _nio (approximately 0). Determine whether or not you have become used to it. This portion corresponds to the acceleration fluctuation amount change detection means.

If ΔTVO>C _nio , the engine is accelerating, so proceed from step 32 to step 27, compare the amount of variation ΔTVO in the throttle valve opening with the maximum value ΔTVO _nax of the amount of variation up to that point, and find that ΔTVO>ΔTVO _nax. In this case, in step 28, the current ΔTVO is set to ΔTVO _nax . Then, proceed to step 29 to set the control time
DLTTIM and control count DLTCNT are each 0.
Make it. Then, in step 30, the ignition advance angle map value MADV is set as the final ignition advance angle ADV, and in the next step 31, it is output.

When ΔTVO≦C _nio , acceleration ends and
This is the state just before the vehicle rolls over, so
Proceeding from step 32 to step 33, the ignition timing is corrected to the advanced side by a predetermined number of times B within a predetermined control time A.

In other words, the control time is
If DLTTIM is less than the predetermined time A, and if the number of controls DLTCNT is less than the predetermined number B as determined in step 34, the number of controls DLTCNT is incremented by 1 in step 35, and then the current engine speed N and the engine speed during acceleration are determined in step 36. The correction amount ΔADV for advancing the ignition timing corresponding to the maximum variation ΔTVO _nax of the throttle valve opening is searched by referring to a map prepared in advance. Then, in the next step 37, the ignition advance angle map value MADV, which is determined by referring to the map from the engine speed N and the basic fuel injection amount Tp, is determined according to the flowchart shown in FIG. 4, which is executed as a background job. By adding the correction amount ΔADV, the final ignition advance angle ADV is determined. thus,
The ignition timing is corrected to the advance side by the amount of correction ΔADV. Then, in step 31, it is output. Here, steps 36 and 37 correspond to ignition timing advance means.

The predetermined control time A has elapsed or the predetermined control number B
If the acceleration is completed, proceed from step 32 or 33 to step 38, set the acceleration judgment flag F to 0, and after setting ΔTVO _nax to 0, proceed to steps 29 to 38.
Proceed to 31 to return to normal control.

With this control, as shown in FIG. 7, the conventional characteristic without correction is shown by a solid line, and the characteristic of this embodiment is shown by a broken line, the variation amount ΔTVO of the throttle valve opening after acceleration
The ignition timing is corrected to the advanced side in the direction of canceling the yaw from the state immediately before the vehicle rolls when yaw becomes almost 0, and sudden torque changes are suppressed.

<Effects of the invention> As explained above, according to the present invention, the state immediately before the vehicle rolls back after acceleration is detected, and the ignition timing is corrected to the advanced side at this time, thereby making it possible to roll back the vehicle. This has the effect of significantly improving driveability and ride comfort. Further, since the ignition timing correction amount is determined in accordance with the expected magnitude of oscillation based on the maximum value of the acceleration variation amount during acceleration, an effect that optimum control can be achieved is also obtained.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the configuration of the present invention;
The figure is a system diagram showing one embodiment of the present invention, Figure 3 is a flowchart of the ignition timing control routine, and Figure 4 is a flowchart of the ignition timing control routine.
The figure is a flowchart of a background job.
FIG. 5 is a control characteristic diagram, FIG. 6 is a flowchart of an ignition timing control routine in another embodiment, and FIG.
The figure is a control characteristic diagram in another embodiment. 1... Engine, 6... Air flow meter, 7...
Throttle valve, 8... Throttle sensor, 9...
Fuel injection valve, 10... Crank angle sensor, 11...
...Ignition plug, 12...Ignition coil, 13...Distributor, 20...Control unit.

Claims (1)

[Scope of Claim for Utility Model Registration] Acceleration determination means for determining the acceleration state of an engine; acceleration variation detection means for detecting at predetermined time intervals the amount of variation in a parameter that changes during acceleration; and after acceleration determination by the acceleration determination means. an acceleration fluctuation amount maximum value detection means for detecting the maximum value of the fluctuation amount; and an acceleration fluctuation amount change that detects that the fluctuation amount becomes equal to or less than a predetermined value after the acceleration determination by the acceleration determination means and generates a detection signal. a detection means; and an ignition timing advance means for receiving the detection signal after the acceleration determination by the acceleration determination means and correcting the ignition timing of the ignition device toward the advance side by an amount corresponding to the maximum value of the variation amount. Acceleration shock prevention device for automobile internal combustion engines.