JPH07117023B2 - Engine controller - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a control device for an internal combustion engine of an electric ignition system such as a gasoline engine, and more particularly to a control device for an automobile engine to prevent jerky operation during acceleration. The present invention relates to an engine control device suitable for operating.

[Conventional technology]

In a vehicle equipped with a gasoline engine, when the accelerator pedal is suddenly depressed to perform an acceleration operation, pulsation with a large acceleration, so-called acceleration surging, may occur, resulting in jerky driving.

Therefore, in order to suppress the occurrence of this jerky operation, a method of detecting the acceleration and controlling the engine torque by changing the ignition timing has been proposed by the invention of Japanese Patent Application No. 61-614. Immediately after the acceleration was detected, the ignition timing correction control was immediately started.

[Problems to be solved by the invention]

In the above-mentioned conventional technique, a temporary decrease in acceleration due to controlling the engine torque immediately after the acceleration is detected is not taken into consideration, and jerky operation can be suppressed, but there is a problem that the feeling of acceleration is impaired. .

An object of the present invention is to provide an engine control device capable of effectively preventing jerky operation while leaving a sufficient acceleration feeling.

[Means for solving problems]

The purpose is to calculate a predetermined ignition timing correction amount based on the rate of change of the engine speed, and correct the basic ignition timing by the predetermined ignition timing correction amount during a predetermined period after the engine is accelerated and controlled. In the engine control device configured to perform the above, the start time of the predetermined period is the time when the rate of change of the engine speed changes from the negative value to the positive value from the time when the engine is accelerated and controlled. Is achieved in this way.

[Work]

Immediately after the accelerator pedal is depressed to enter acceleration control, the ignition timing is not corrected until the rate of change in engine speed changes from a negative value to a positive value. A temporary decrease in torque is suppressed, and a sufficient sense of acceleration can be given.

At this time, the time from the start of acceleration control to the start of correction of the ignition timing is precisely defined as the period from once the engine is accelerated to when it decelerates to the next acceleration. Therefore, even if the acceleration performance of the engine changes, it is possible to always obtain a sufficient sense of acceleration and to obtain the correction of the ignition timing immediately before shifting to the jerky operation.

〔Example〕

Hereinafter, an engine control device according to the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 6 shows an example of an engine system to which the present invention is applied. In FIG. 6, the air to be taken in by the engine enters from the inlet portion 2 of the air cleaner 1 to detect the intake air amount. Air flow meter (air flow sensor)
3, a duct 4, a slot body 5 having a throttle valve (slottle valve) for controlling the air flow rate, and a collector 6
to go into. Here, the air is distributed to each intake pipe 8 that directly passes through the internal combustion engine 7, and is sucked into the cylinder.

On the other hand, fuel is sucked from the fuel tank 9 by the fuel pump 10,
It is pressurized and supplied to the fuel system in which the fuel damper 11, the fuel filter 12, the injection valve 13, and the fuel pressure regulator 14 are piped. Then, this fuel is regulated to a constant pressure by the regulator 14, and is injected into the intake pipe 8 from an injection valve (injector) 13 provided in the intake pipe 8.

Further, a signal for detecting the intake air amount is output from the air flow sensor 3, and this output is a control unit.
It is supposed to be input to 15.

Further, a slot sensor 18 for detecting the opening of the throttle valve is attached to the slot body 5, and a signal from this sensor is also input to the control unit 15.

16 is a dust (day reviewer), and this dust 16
Has a built-in crank angle sensor, and outputs a reference signal for the injection timing and the ignition timing and a signal for detecting the rotational speed, which is input to the control unit 15.

FIG. 7 shows the details of the control unit 15, which is composed of an arithmetic unit including an MPU, a ROM A / D converter, and an input / output circuit as shown in FIG. Predetermined arithmetic processing is performed based on the output signal and the like, and the output signal which is the result of the arithmetic is used to operate the injector 13 to inject a required amount of fuel into each intake pipe 8. Further, the ignition timing is controlled by sending a signal to the power transistor of the ignition coil 17.

Next, the control operation of an embodiment of the engine control device according to the present invention having the above-mentioned configuration will be described.

FIG. 1 shows an ignition timing control method according to an embodiment of the present invention.

When the throttle valve 5 is opened and acceleration control is performed, the engine speed N rises with periodic fluctuations as shown in FIG. As described above, this is due to a phenomenon called so-called accelerated surging.

However, if the fluctuation range of the engine speed N at this time becomes larger than a certain level and appears for a considerable period of time, so-called jerky operation will result.

On the other hand, the existence of the first portion A of the rotational speed increase at this time is indispensable for giving a feeling of acceleration.

Therefore, in the present invention, while leaving the rising portion A, only the fluctuation of the rotational speed after that is suppressed. Therefore, in the following embodiments, the engine is first subjected to acceleration control. Is detected by the change amount Δθ _th of the throttle opening per unit time, the change amount ΔQa of the air amount, or the change amount ΔTp of the fuel injection pulse width Tp, and then the fluctuation of the engine speed N is differentiated by the differential value dN / dt. Then, the ignition timing is corrected by the amount of change and the sign.

Specifically, after acceleration detection, from a predetermined number of sign inversions,
In this embodiment, the correction amount corresponding to the amount of change in the number of revolutions from the negative to the first inversion is obtained from the table shown in FIG. 2, and the basic ignition timing is corrected.

A flow chart for executing the above control will be described with reference to FIG.

Step 100: In this step, the engine speed N obtained from the output signal of the crank angle sensor, the basic ignition timing IGNM from the memory map, and the output signal θ _th of the throttle sensor are read based on the signals of the sensor and the air flow sensor. This reading is performed every predetermined time.

Step 101; A change amount Δθ _th per unit time of θ _th read in step 100 is calculated, and if the Δθ _th is larger than a predetermined value Δθ _thREF, it is determined to be acceleration. The amount of air is used to determine acceleration.
Qa or pulse width Tp may be used.

Step 102; It is determined whether the sign of dN / dt after acceleration detection is inverted from negative to positive or whether it is the first inversion.

Step 103; Differentiate the engine speed N read at Step 100 from dN / dt
Then, it is determined whether or not the value of dN is larger than the predetermined value N _REF . If it is smaller, the basic ignition timing is not corrected.

Step 104; correction amount ΔIGN according to the value of change amount dN obtained in step 103
Is obtained from a memory map having the characteristics shown in FIG.

Step 105; It is determined whether the sign of the rotation speed change amount dN / dt obtained in Step 103 is positive or negative, and it is determined whether the rotation speed is in the ascending direction or in the descending direction.

Step 106; If it is determined in Step 105 that the rotational speed is in the increasing direction, the correction amount ΔIGN obtained in Step 104 is set to the basic ignition timing IG.
Correct the ignition timing by subtracting from NM.

Step 107; If it is determined in Step 105 that the rotational speed is in the descending direction, the correction amount ΔIGN obtained in Step 104 is used as the basic ignition timing IG.
The ignition timing is corrected by adding it to NM.

Step 108: In this step, IGN read in step 100 or IGN obtained in steps 106 and 107 is stored at a predetermined address to prepare for actual ignition timing control.

Step 109: It is judged whether or not the sign of dN / dt after the acceleration is detected is changed from negative to positive for the second time. If it is the second reversal, the correction of the ignition timing is stopped.

FIG. 4 shows a result of an acceleration test conducted on an actual vehicle in the above-described embodiment, and FIG. 5 shows a result of the acceleration test with the conventional technique.

As is clear from a comparison between the above two data, in the embodiment of the present invention, the value of the first rising of the vehicle longitudinal acceleration G is g _r.
Thus, it can be seen that the value is larger than the value g _x in the conventional technique, and the feeling of acceleration is improved. On the other hand, the subsequent change in the acceleration G is equivalent to that in the conventional technique, and the jerky operation can be prevented.

Next, a prior art example examined in the process of reaching the present invention will be described.

FIG. 8 shows a method of controlling the ignition timing according to the preceding example. The difference between the example of FIG. 1 and the example of FIG. 1 is that the ignition timing is corrected for a predetermined time after the acceleration is detected. T _SET (Se
c) The process is performed only for a predetermined time T _k (Sec) after that, which means that a time delay until the correction of the ignition timing is started after the acceleration is detected is kept until a certain time.

A flow chart for executing this prior example will be described with reference to FIG. Note that the same reference numerals as those in FIG. 3 perform the same processing as in FIG. Therefore, only the points different from FIG. 3 will be described.

Step 110: Set the time T _SET (Sec) from the detection of acceleration to the start of correction of the ignition timing, and the correction time T _k (Sec).

Step 111; Judge that T _{SET has} elapsed since acceleration was detected.

Step 112: It is judged whether T _k (Sec) has elapsed since the ignition timing correction was started.

Even with this precedent, it was possible to leave a sense of acceleration for the time being.

As described in Figure 1, to begin to correct the ignition timing by the sign of dN / dt, as it explained in FIG. 8, the predetermined time T _k
Even if it was stopped after (sec), a considerable effect could be obtained.

Further, as described with reference to FIG. 8, after the acceleration is detected, the ignition timing correction is started after a predetermined time T _SET (Sec),
As described with reference to FIG. 1, even if the sign of dN / dt is inverted from negative to positive and the correction is stopped at a predetermined number of times, a considerable performance is obtained.

〔The invention's effect〕

As described above, according to the present invention, the first increase in the engine speed after the acceleration control is made to appear as it is. Therefore, it is possible to effectively suppress the occurrence of jerky operation while sufficiently leaving a feeling of acceleration. The driving feeling can be greatly improved.

[Brief description of drawings]

FIG. 1 is a control characteristic diagram of an embodiment of an engine control device according to the present invention, FIG. 2 is a characteristic diagram showing an ignition timing correction amount, and FIG. 3 is a flow chart showing the operation of the embodiment of the present invention. FIG. 4 is a characteristic diagram showing the effect of one embodiment of the present invention,
FIG. 5 is a characteristic diagram of a conventional example, FIG. 6 is a block diagram of an engine system to which an embodiment of the present invention is applied, FIG. 7 is a block diagram showing an embodiment of a control unit, and FIG.
FIG. 9 is a characteristic diagram of the preceding example of the present invention, and FIG. 9 is a flowchart showing the operation of the preceding example of the present invention. 3 ... Air flow sensor, 7 ... Internal combustion engine, 13 ... Injector, 15 ... Control unit, 16 ... Distributor with built-in crank angle sensor, 17 ... Ignition coil, 18 ... Slot sensor.

Claims (3)

[Claims] 1. A predetermined ignition timing correction amount is calculated based on a rate of change in engine speed, and a basic ignition timing is corrected by the predetermined ignition timing correction amount during a predetermined period after the engine is accelerated and controlled. In the engine control device configured to perform control, the start time of the predetermined period is the time when the rate of change of the engine speed changes from the negative value to the positive value from the time when the engine is accelerated and controlled. An engine control device characterized by being configured as follows. 2. The end point of the predetermined period according to claim 1, wherein the rate of change of the number of revolutions of the engine is negative from a negative value a predetermined number of times after the engine is accelerated and controlled. An engine control device, which is configured so that it becomes a time point when it changes to a positive value. 3. The engine control device according to claim 1, wherein the end time point of the predetermined period is a time point after a predetermined time has elapsed from the start time point.