JPS6189979A - Ignition timing controller for engine - Google Patents

Abstract

PURPOSE:To perform optimum accelerating compensation, by installing an acceleration judging device, which judges engine acceleration with output of a throttle opening sensor, and also an accelerating compensation device which performs accelerating compensation for ignition timing with this judging device. CONSTITUTION:A fundamental timing advance angle is calculated according to engine speed and suction negative pressure at a step 110. In time of engine acceleration running, a timing delay value and timing delay duration are calculated at a step 114. A span of the duration should be set to be the longer the larger in a variation of throttle opening in time of acceleration. At a step 115, accelerating compensation takes place on the basis of the timing delay value calculated at the step 114. Thus, optimum accelerating compensation is performable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ignition timing control device for an engine, and particularly to an ignition timing control device that performs acceleration correction of the ignition timing during accelerated operation of the engine.

[Prior Art] Conventionally, in an electronic ignition timing control device that calculates the ignition timing of an engine according to engine speed and intake negative pressure, for example, when the engine is accelerating, an acceleration signal is used to control the energization time to the igniter. An engine ignition timing control device that performs acceleration correction of the ignition timing by increasing the number of ignition timings is known (see Japanese Patent Laid-Open No. 135754/1983).

This type of acceleration correction causes the air-fuel ratio to become lean as a large amount of intake air is temporarily supplied to the engine at the beginning of acceleration, and if ignition is performed at a normal advance angle, 7-knocking will occur. This prevents knocking by retarding the timing.

By the way, engine acceleration includes so-called sudden acceleration, in which the accelerator pedal is suddenly depressed, and so-called slow acceleration, in which the accelerator pedal is gradually depressed.

Now, in a patent that detects the acceleration of the engine when, for example, the throttle opening speed (rate of change) becomes larger than a predetermined value, and performs acceleration correction only during that time, during sudden acceleration, the throttle valve rapidly changes. The throttle valve is opened, and the engine charge increases with a certain time delay relative to the opening of the throttle valve.
Acceleration correction is performed before the charge amount increases, causing the ignition timing to be delayed too much, making it impossible to obtain the necessary acceleration performance.In addition, when the charge amount actually increases, the acceleration correction ends and knocking is prevented. Occur. On the other hand, when the engine is slowly accelerating, acceleration correction will be performed as long as the throttle opening speed is greater than the above-mentioned predetermined value even after the charging amount is almost saturated. There is a problem in that setting it on the lag side causes hesitancy.

[Object of the Invention] An object of the present invention is to enable optimal acceleration correction to be performed in consideration of the acceleration state when performing acceleration correction of the ignition timing of an engine.

[Structure of the Invention] Therefore, in the present invention, the end of acceleration is detected and acceleration correction is continued for a predetermined period of time from the end of acceleration, and the predetermined period of time for performing the acceleration correction is determined by detecting the change in throttle opening. During sudden acceleration, when the rate of change in throttle opening is large depending on the speed, the predetermined time is set to be longer, while during slow acceleration, the predetermined time is set to be shorter, so that the acceleration correction is terminated early. .

[Effects of the Invention] According to the present invention, the acceleration state of the engine can be detected with good responsiveness based on changes in the throttle opening degree, and excessive control of the ignition timing after the intake negative pressure has stabilized can be reliably prevented. Accurate acceleration correction can be performed depending on the acceleration state.

[Example] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

As shown in Fig. 3, in the combustion chamber 2 of the engine 1,
For spark plug 3 installed facing 1,
A drive circuit 4 for driving the ignition, and an ignition timing control circuit 5 for controlling the drive circuit 4 are provided. The ignition timing control circuit 5 is configured by a microcomputer, and is connected to an air 70 interposed in an intake passage 7 downstream of the air cleaner 6.
-Intake air amount detected by meter 8, air 70-
The throttle opening is detected by a throttle opening sensor 10 provided for the throttle valve 9 provided downstream of the meter 8, and the negative pressure sensor 12 provided for the surge tank 11 provided downstream of the throttle valve 9. Furthermore, the engine rotation speed sensor IL'1% temperature sensor 14. Cooling water temperature sensor 15. Ignition is performed by executing the control flow shown in FIGS. 1 and 2 using each output of the ignition switch IgSW and the output of a pickup type crank angle sensor 16 provided for the output shaft of the engine (not shown) as input. Set the time.

Hereinafter, the ignition timing setting method executed by the ignition timing control circuit 5 will be explained according to charts 70 in FIGS. 1 and 2.

When the control is started now, the background routine shown in Fig. 2 is executed, first the system is initialized in step 201, the intake negative pressure is read in step 202, and the idle switch is turned on and off in step 203. In step 204, the starter signal is read, in step 205, the throttle opening is read, in step 206, the engine coolant temperature is read, and in step 207, the intake air temperature is read.

Now, when a reference signal corresponding to a predetermined crank angle is input while the above-mentioned background routine is being executed, the ignition timing control circuit 5 executes the interlaced routine shown in FIG. 1 to set the ignition timing. Do the following.

This interwoven routine will be explained below according to the control flow shown in FIG.

When this interwoven routine is started, the rotation period of the engine 1 is calculated from the output of the crank angle sensor 16 in step 101, and the rotation period is converted into the engine rotation speed in step 102. Then, in step 103, an average value is calculated from the previous intake negative pressure and the current intake negative pressure. Next step 1
In step 04, it is determined whether the starter is off, and if the starter is off, it is determined in step 105 whether or not the engine rotation speed at that time is equal to or higher than a predetermined rotation speed. If the starter is on, there is (1 means step 1 when the engine speed has not reached the set speed above)
At 06, switch to hard ignition. In other words, the ignition timing is set by a fixed advance angle.

On the other hand, during operation when the starter is turned off and the engine speed has risen above the set speed, step 107
Switch to soft ignition at .

That is, from now on, the necessary ignition timing will be set depending on the operating state of the engine. First, in step 108, it is determined whether or not the vehicle is idling. If the vehicle is idling, the idling advance angle is calculated in step 109.

On the other hand, when the operation is not idling, step 110
The basic advance angle is calculated based on the smell. This basic advance angle is
It is read out from a basic ignition timing setting map stored in the ROM of the microcombiner in accordance with the engine speed and intake negative pressure at that time. Next, in step 111, a correction advance angle is calculated according to the engine cooling water temperature and intake air temperature, and then, in step 112, an EGR correction (EGR correction) is calculated.
(during operation when GR is being performed) is calculated. After the various corrections described above, in step 113, the rate of change of the throttle opening is calculated from the previous and annual sampling values, and it is determined whether the rate of change is greater than or equal to the set value, and the rate of change of the throttle opening is calculated. When the engine is operating at an accelerated speed such that the value exceeds the set value, the process proceeds to step 114, where the amount of retardation and the duration of retardation are calculated.

The retard amount described above can usually be given as a constant value, but may be set as a function of the rate of change of the throttle opening if necessary. In addition, the retard duration time refers to the time during which the ignition timing retard correction continues from the time when the rate of change of the throttle opening becomes less than the above set value, that is, from the end of acceleration, and the length of the retardation time. is set longer as the rate of change in the throttle opening degree during acceleration is larger, and is set shorter during slow acceleration when the rate of change in the throttle opening degree is smaller so that the acceleration correction ends relatively early.

Then, in step 115, acceleration correction is performed based on the amount of retardation calculated in step 114, and finally, in step 116, ignition timing is adjusted based on the advance angle after performing each of the above corrections on the basic advance angle. Preset the advance angle in the ignition counter to be set. Note that step 113
At the end of acceleration when it is determined that the rate of change of the throttle opening is less than or equal to the set value, it is determined in step 117 whether or not the retardation m duration calculated in step 114 has ended; If so, acceleration correction is performed in step 115. In other words, after acceleration ends, acceleration correction continues for the retardation duration time. When the retardation duration period ends, step 115 is skipped and the process proceeds to step 116, where the ignition advance angle is preset in the ignition counter without performing acceleration correction.

As described above, in the present invention, acceleration correction is performed at the end of acceleration?
−＋＋ −zu−j 笥りにてししβn Ｇａｎｔ＋ １
Toni rl Top, - This predetermined time is set according to the rate of change in throttle opening during acceleration, so that it is set longer when the rate of change is large and shorter when it is small, so in the case of sudden acceleration, the increase in charging amount is It is possible to effectively deal with delays, and also to prevent excessive retardation by terminating acceleration correction early during slow acceleration.

[Brief explanation of drawings]

FIG. 1 is a 70-chart diagram of the control executed by the ignition timing control device according to the present invention, FIG. 2 is a 70-chart diagram of the bank ground routine executed by the ignition timing control device, and FIG. 3 is the above-mentioned 1 is a system configuration diagram of an ignition timing control device. 1...Engine, 3...Spark plug, 4...
・Drive circuit, 5... Ignition timing control circuit, 10.
...Throttle opening sensor.

Claims (1)

[Claims] (1) It has an acceleration determination means that controls the ignition timing based on the engine rotation speed and intake negative pressure and determines the acceleration based on the output of the throttle opening sensor, and an acceleration correction means that performs acceleration correction of the ignition timing using the determination means. The ignition timing control device for an engine is characterized in that the acceleration correction is continued for a predetermined period of time from the time when the end of acceleration is determined by a throttle opening sensor, and the predetermined period of time is lengthened as the rate of change in the throttle opening increases. Engine ignition timing control device.