JPH086668B2 - Ignition timing control device for internal combustion engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a control system for an internal combustion engine of an electric ignition type such as a gasoline engine, and more particularly, to a control system for an automobile engine, in which the vehicle travels in a jerky state during deceleration ( The present invention relates to an ignition timing control device for an internal combustion engine suitable for preventing the occurrence of (operation).

[Prior Art] For example, in a vehicle such as an automobile equipped with a gasoline engine, when the accelerator pedal is suddenly released to perform deceleration operation, a large fluctuation in traveling speed, that is, a deceleration surge occurs. It may lead to driving.

Therefore, in order to suppress the occurrence of such jerky operation, a method of detecting deceleration and controlling the torque of the engine by changing the ignition timing at this time is disclosed in, for example, JP-A-62-62.
It is disclosed in Japanese Patent Publication No. 159771.

By the way, in this conventional example, the ignition timing is corrected by adding a predetermined ignition timing correction amount for each ignition timing.
It has come to be executed by repeating this a predetermined number of times.

[Problems to be Solved by the Invention] In the above-described conventional technology, consideration is given to the magnitude of surging during deceleration, that is, the magnitude of rotation speed fluctuation, and the basic ignition timing at this time. However, there was a problem that a sufficient surging suppression effect could not be expected.

An object of the present invention is to make it possible to sufficiently suppress the occurrence of surging, eliminate jerky operation at the time of fuel supply recovery after fuel cut control by deceleration, and easily obtain good operating characteristics. It is to provide an ignition timing control device for an engine.

[Means for Solving Problems] The purpose is to detect deceleration, calculate the engine speed change amount and basic ignition timing at this time, and calculate ignition timing correction data based on the engine rotational speed. Thus, after the engine is subjected to the fuel cut control, the ignition timing correction is started when the fuel supply is restored.

[Operation] Since the ignition timing correction data is calculated on the basis of the actual number of revolutions when the engine is decelerated and its fluctuation amount, and the basic ignition timing at this time, the ignition timing control is performed. The magnitude of the torque control by means is that it sufficiently corresponds to the fluctuation of the engine speed, and as a result, the surging at the time when the fuel supply is restored after the engine is fuel cut controlled is effectively suppressed and the It is possible to reduce the driving speed.

[Embodiment] Hereinafter, an ignition timing control device for an internal combustion engine according to the present invention will be described in detail with reference to the illustrated embodiment.

FIG. 2 shows an example of an engine system to which the present invention is applied. In the figure, the air to be sucked from the engine is taken in from the inlet portion 2 of the air cleaner 1, and the hot-wire air flow rate for detecting the intake air amount. A collector (6) is passed through a meter (air flow sensor) 3, a duct 4, and a slot body 5 having a throttle valve (slottle valve) for controlling the air flow rate. 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 and pressurized by the fuel pump 10 from the fuel tank 9, the fuel damper 11, the fuel filter 12, and the injection valve.
13, the fuel pressure regulator 14 is supplied to the fuel system in which it is 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.

A signal for detecting the intake air amount is output from the air flow sensor 3, and this output is input to the control unit 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.

Reference numeral 16 is a dust (distributor), which has a built-in crank angle sensor, which outputs a reference signal for injection timing and ignition timing and a signal for detecting the rotational speed, which is input to the control unit 15. It is becoming like this.

FIG. 3 shows the details of the control unit 15. As shown in FIG. 3, the control unit 15 is composed of an arithmetic unit including an MPU, ROM, A / D converter, and an input / output circuit.
A predetermined arithmetic processing is performed by the output signal of the output signal of the dust 16, the output signal of the dust 16, etc., and the injector 13 is actuated by the output signal which is the calculation result so that a required amount of fuel is injected into each intake pipe 8. ing. 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 ignition timing control device for an internal combustion engine according to the present invention having the above-described structure will be described.

FIG. 1 is a timing chart showing an ignition timing control operation according to one embodiment of the present invention, and it is assumed that the throttle valve is suddenly returned at a certain point in time and the opening degree θth thereof starts to be greatly reduced.

Then, as a result, the engine speed Ne periodically fluctuates as shown in the figure, causing pulsation.

Therefore, in order to prevent this, this throttle opening θ
It is judged whether the rate of change dt / dθth of th has reached a predetermined value,
When it is determined from the result that the engine has entered the deceleration state, the retard correction and the advance correction with respect to the basic ignition timing are performed.

At this time, the ignition timing correction amount is, as shown in FIG. 4, a correction coefficient ΔIGN _n (n = 1 to n), which is given as a function of a change amount dNe of the engine speed Ne per predetermined time,
For example, the basic ignition timing given as a map search value or a table search value based on data representing the engine load.
Corresponding to ADV _n (n = 1 to n), as shown in FIG.
A correction coefficient nK _R (when the engine speed increases) or a correction coefficient nK _A (when the engine speed decreases) and a function of the engine speed Ne as shown in FIG. Using the correction coefficient nKN given as
It is calculated by the following formula.

ΔIGN = ΔIGN _n × nK _{R (A)} × nKN (1) Then, the ignition timing correction amount ΔIGN obtained in this way
Is subtracted from the basic ignition timing ADV _n when the engine speed increases, and is added when the engine speed decreases, and the ignition timing at that time is obtained.

It should be noted that the above calculation method of the correction amount is an example, and instead of this, the change amount dNe of the engine speed is directly multiplied by the correction coefficient nK _{R (A)} and nKN to obtain the correction amount. It may be calculated, or may be calculated by the following equation.

ΔIGN = ΔIGN _n · (1 + nK _{R (A)} + nKN) (2) Figures 7 and 8 show the actual vehicle
With the gear of the transmission in the second gear, the engine speed Ne =
The measurement results of the engine speed Ne, ignition timing IGN, and vehicle longitudinal acceleration G when deceleration operation was performed by rapidly returning the throttle valve from 1500 rpm constant speed to the fully closed position (slottle opening θth = fully closed) FIG. 7 shows the test result when one embodiment of the present invention is applied, and FIG. 8 shows the test result in the conventional example. In addition, here
For reference, indicated mean effective pressure pi and fuel injection pulse width
Ti is also shown.

As is apparent from FIGS. 7 and 8, according to this embodiment, surging during deceleration is suppressed, discomfort due to rattling vibrations is eliminated, and riding comfort can be sufficiently improved.

By the way, in such engine control devices, fuel cut control is often performed during deceleration.

Therefore, in such a case, the above-mentioned correction of the ignition timing may not be performed after the fuel cut and until it is recovered.

9 and 10 show the test results of the actual vehicle when the fuel cut control is applied. As in the case of FIGS. 7 and 8, FIG. 9 shows an embodiment of the present invention. Fig. 10 shows the conventional example when applied, and in these figures, the F / R restores the fuel supply again during the period when the F / C is in the fuel cut (fuel cut).
Represents the time when each was done.

As is apparent from FIGS. 9 and 10, according to the present invention, it is possible to reliably suppress surging even when the fuel cut control is applied during deceleration, which is useful for improving the riding comfort. .

By the way, the correction control of the ignition timing described above is executed by the MPU (FIG. 3) in the control unit 15, and this processing will be described with reference to the flow charts of FIG. 11 and FIG. Note that these Fig. 11 and
The only difference in the processing of Fig. 12 is that the former discriminates fuel cuts, while the latter discriminates fuel recovery.

All of these processes are periodically executed, and various data necessary for the process are first read (S1). Next, it is determined whether or not the rate of change −Δθth in the decreasing direction of the throttle opening θth is equal to or more than a predetermined value X (S2).
That is, it is determined whether or not the deceleration state has been reached.

Then, it is judged whether or not the fuel cut is in progress, or whether or not the fuel has been recovered (S3, S30). After waiting for a predetermined time, the rate of change dNe of the engine speed Ne is calculated (S5), and then S6.
Then, the correction coefficient nKN corresponding to the engine speed Ne is calculated.

Next, in S7, the sign of the rate of change dNe of the engine speed Ne is checked, and the subsequent processing contents are changed depending on the result.

First, when the result in S7 is YES, it means that the engine speed is increasing, so the correction is made to delay the ignition timing. Therefore, first, the correction coefficient nK _R is calculated (S
8), this correction coefficient nK _R and the correction coefficient nK already obtained
The ignition timing correction amount ΔIGN is calculated from N and the change rate dNe (S9), and finally the ignition timing correction amount ΔIGN is subtracted from the basic ignition timing ADVn to calculate the ignition timing IGN (S10).
Of.

On the other hand, when the result in S7 is NO, it indicates that the engine speed is decreasing, so this time the correction is made to advance the ignition timing.Therefore, first in S11, the process for obtaining the correction coefficient nK _A is executed. Then, in S12, the ignition timing correction amount ΔIGN is calculated using the correction coefficient nK _A , and finally, in S13, the ignition timing correction amount ΔIGN is added to the basic ignition timing ADVn to obtain the ignition timing IGN. .

In S14, the basic ignition timing ADVn (S2, S3, S4, S30, S40 directly as it was already read in S1 is directly
This S14)), or the corrected ignition timing IGN
One of them (when shifting from either S10 or S13) is stored at a predetermined address so that it can be used for ignition timing control.

In the embodiment of FIGS. 11 and 12, the calculation method of the ignition timing correction amount ΔIGN is different from the above equations (1) and (2), and the present invention is based on this method. It turns out that it may be implemented.

[Advantages of the Invention] According to the present invention, since the ignition timing is corrected using the engine speed during deceleration, the amount of change thereof, and the basic ignition timing as variables, engine torque control when the engine is decelerated. The contents of the section fully correspond to changes in the engine speed, so the torque control necessary to suppress surging can always be obtained accurately, jerky driving can be sufficiently suppressed, and riding comfort of automobiles etc. can be easily improved. Obtainable.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a timing chart explaining a control operation in an embodiment of the present invention, FIG. 2 is a block diagram of an engine system to which the embodiment of the present invention is applied, and FIG. Block diagrams showing details of the control unit, Fig. 4, Fig. 5
FIG. 6 is a characteristic diagram of a correction coefficient, FIG. 7 is a timing chart showing a rotation speed control characteristic in one embodiment of the present invention, and FIG. 8 is a timing chart showing a rotation speed control characteristic in a conventional example. FIG. 9 is a timing chart showing a rotation speed control characteristic in one embodiment of the present invention,
FIG. 10 is a timing chart showing the rotation speed control characteristic in the conventional example, and FIGS. 11 and 12 are flow charts for explaining the operation of one embodiment 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 (1)

[Claims] 1. A deceleration determining means for detecting that the internal combustion engine has entered a predetermined deceleration state, and a rotational speed change direction determining means for detecting whether the rotational speed of the internal combustion engine is in a decreasing direction or an increasing direction. And a calculation means for calculating ignition timing correction data based on each data of the rotational speed of the internal combustion engine, the basic ignition timing calculated according to the operating conditions of the internal combustion engine, and the change rate of the rotational speed of the internal combustion engine. When the determination result by the deceleration determination means is affirmative,
In an ignition timing control device for an internal combustion engine, wherein the basic ignition timing is retarded and advanced based on the ignition timing correction data in accordance with the determination result of the rotational speed change direction determining means, A determination means for detecting that the engine is in the cut control state is provided, and after the determination result by the deceleration determination means becomes affirmative, during the period in which the internal combustion engine is in the fuel cut state, the retard correction with respect to the basic ignition timing is performed. Ignition timing of an internal combustion engine, characterized in that, when the start of the advance angle correction is prohibited and thereafter the fuel supply is restored, the retard angle correction and the advance angle correction with respect to the basic ignition timing are started. Control device.