JPH0711263B2 - Ignition timing control device for internal combustion engine - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition timing control device for an internal combustion engine, and more particularly to a technique for suppressing shock during acceleration by ignition timing control.

<Prior Art> In a conventional internal combustion engine for an automobile, particularly an internal combustion engine equipped with an electronically controlled fuel injection device, fuel injection is performed with high responsiveness according to the engine operating state, so that the throttle valve is opened during acceleration operation. The combustion pressure (the indicated mean effective pressure) follows the temperature change with good responsiveness.

<Problems to be solved by the invention> However, since the vehicle has a large weight and a large inertia, it is not possible to follow the output of the engine with good responsiveness, so when accelerating and shifting to a steady state, Jerky vibrations are generated due to the rolling back of the vehicle (variation in the front-rear direction G of the vehicle), and rotational fluctuations of the engine are generated, which deteriorates drivability and riding comfort.

Therefore, after acceleration, the ignition timing is retarded to suppress the engine speed from starting to decrease, and then the ignition timing is retarded when the engine speed increases and retarded when the engine speed decreases to suppress the rotational fluctuation. There are also some.

However, when the ignition timing correction is started after the end of acceleration, the basic ignition timing set corresponding to the steady state of the engine operation is set immediately after the start so as to increase the torque as much as possible in the operating state. Since it is a value (so-called optimum ignition timing), even if this ignition timing is corrected in the advance direction, the torque will not be increased any more, and the decrease in rotation speed cannot be suppressed, so fluctuations in rotation speed are suppressed. It could not be suppressed well.

That is, in order to increase the number of revolutions by the advance angle correction, it is necessary that the ignition timing before the advance angle correction is on the retard side in advance from the optimum ignition timing so that the advance timing approaches the optimum ignition timing.

The present invention has been made by focusing on such a conventional problem, and corrects a predetermined amount of ignition timing to a retard side in advance during acceleration,
It is an object of the present invention to provide an ignition timing control device for an internal combustion engine, which solves the above-mentioned problems by performing advance / retard correction according to a change in the number of revolutions thereafter.

<Means for Solving Problems> Therefore, according to the present invention, as shown in FIG. 1, the engine operating state detecting means for detecting the operating state of the engine and the engine operating state detected by the operating state detecting means are provided. A basic ignition timing setting means for setting a basic ignition timing based on the acceleration determination means for determining the acceleration state of the engine based on the engine operating state detected by the operating state detecting means; and a steady state by the acceleration determining means. A time measuring means for measuring an elapsed time from the time when it is determined that the acceleration state is entered, and a first ignition timing correction for correcting the basic ignition timing to a retard side by a predetermined amount for a predetermined time after the start of measurement by the time measuring means. Means, and after the predetermined time has elapsed after the start of measurement by the time measuring means,
A second ignition in which the ignition timing corrected by the first ignition timing correction means is used as an initial value, and the ignition timing is corrected according to the amount of change in a direction to suppress the engine rotation variation detected by the operating state detection means. And a timing correction means, and an ignition signal output means for outputting an ignition signal to the ignition device at the ignition timing corrected by the first ignition timing correction means and the second ignition timing correction means.

<Operation> When the steady state shifts to the acceleration state, the basic ignition timing is corrected to the retard side by the predetermined amount for the predetermined time measured by the time measuring means.

After the engine speed has started to decrease after the lapse of the predetermined time, the fluctuation in the rotation speed is suppressed, that is, the correction is performed in the direction in which the ignition timing is advanced with respect to the decrease in the rotation speed.
At that time, since the initial value of the ignition timing is corrected in advance to the retard side, the ignition timing is corrected by advancing the ignition timing to increase the torque and suppress the decrease in the rotation speed, and the subsequent fluctuation in rotation is excellent. Can be suppressed to.

<Example> An example of the present invention will be described below with reference to the drawings.

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

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

The control of the fuel injection amount is calculated in the microcomputer incorporated in the control unit 20 based on the intake air flow rate Q detected by the air flow meter 6 and the signal from the crank angle sensor 10 incorporated in the distributor 13 described later. The basic fuel injection amount Tp = K · Q / N (K is a constant) is calculated from the engine speed N and the fuel injection amount Ti = Tp · COEF + Ts (COEF includes an acceleration correction coefficient etc.) Various correction factors, Ts is a voltage correction amount), and a drive pulse signal having a pulse width corresponding to this is set in the engine 1.
It is performed by giving the fuel injection valve 9 at a predetermined timing in synchronism with the rotation of.

Each cylinder of the engine 1 is provided with a spark plug 11, to which a high voltage generated in an ignition coil 12 is sequentially applied via a distributor 13, whereby spark ignition is performed to ignite and burn an air-fuel mixture. . Here, the ignition coil 12 has its high voltage generation timing 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 with the ignition signal from the control unit 20.

In order to control the 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 parameters of the engine operating state. Further, the throttle valve opening TVO detected based on the signal from the throttle sensor 7 is used.

Here, the air flow meter 6, the throttle sensor 8, and the crank angle sensor 10 correspond to the engine operating state detecting means, and the ignition coil 12, the distributor 13, and the spark plug 11 constitute an ignition device.

CP of microcomputer in control unit 20
In U, arithmetic processing is performed according to the flowchart of FIG. 3 to control the ignition timing (ignition advance) ADV.

In step 1 (denoted as S1 in the figure. The same applies to the following), the previous engine speed No _L d is subtracted from the current engine speed N to calculate the engine speed fluctuation amount ΔN.

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

In step 3, the previous throttle valve opening TVOo _L d is subtracted from the current throttle valve opening TVO to calculate the change amount ΔTVO of the throttle valve opening. Then, in step 4, the variation amount ΔTVO of the throttle valve opening and the acceleration determination value Cacc _C are compared. This part corresponds to the acceleration determination means.

Here, when the variation amount ΔTVO of the throttle valve opening is less than Cacc _{C, the} routine proceeds to step 5, and the acceleration determination flag F is maintained at 0. Then, in the next step 6, the map value MADV (basic ignition timing) of the ignition advance angle determined by referring to the map from the engine speed N and the basic fuel injection amount Tp is finally determined according to a routine executed as a background job. Ignition advance angle ADV and output in the next step 7.

Here, the part of step 6 corresponds to the basic ignition timing setting means, and the part of step 7 corresponds to the ignition signal output means.

In the determination in step 4, if the variation amount ΔTVO of the throttle valve opening is equal to or greater than the acceleration determination value Cacc and it is determined to be accelerated, the process proceeds to step 8 and the acceleration determination flag F is set to 1.

Next, in step 9, TIM of control time is set to 0. Then, in the next step 10, a value obtained by subtracting a predetermined retard angle amount ΔADV ₀ from the ignition advance angle map value MADV determined by referring to the map is set as the final ignition advance angle ADV, and the next step 7
To output. The control time TIM is a timer value that is automatically timed by a timer, and thus this timer corresponds to a time measuring means.

After the acceleration determination is made and the acceleration predetermined flag F is set to 1, the process proceeds to step 11 onward in the determination of step 2, and within the predetermined time B, the correction of the retard amount ΔADV ₀ is maintained, and then the predetermined amount is further determined. Within the time (A-B), advance / retard control is performed according to the rotation speed fluctuation amount.

That is, the control time TIM is determined to be the predetermined time A according to the determination in step 11.
When it is less than the predetermined time, the TIM within the control time is compared with the predetermined time B which is smaller than A in step 12, and when it is less than the predetermined time, step 10
After that, the control for connecting the ignition advance angle with a value obtained by subtracting the retard value ΔADV ₀ from the map advance value MADV is connected. During this period, the value of the timer TIM is incremented in step 16.

Here, the predetermined time B is set close to the time immediately before the state in which the engine speed starts to decrease after acceleration starts to cause the vehicle to swing back. This is roughly determined by the natural frequencies of the front and rear G of the vehicle, and is experimentally obtained. However, the fluctuation amount ΔN of the rotation speed detected in step 1
The control of step 10 may be continued until is near 0. The function of advancing the map advance value MADV by the predetermined amount ΔADV ₀ by advancing to step 10 during the predetermined time B set by step 12 corresponds to the first ignition timing correcting means.

When it is determined in step 12 that the control time is equal to or longer than the predetermined time B (less than A), the process proceeds to step 13 to count up the timer TIM for measuring the control time.

Next, at step 14, in accordance with the rotational speed fluctuation amount ΔN (value including positive and negative) obtained at step 1, the advance / retard correction amount ΔAD
Search V from the map stored in ROM.

Then, in step 15, the ignition advance angle ADV is set to the map advance value MAD.
The value is set as a value obtained by adding the advance / retard angle correction amount ΔADV to a value obtained by subtracting the predetermined retard angle amount ΔADV ₀ from V, and output in step 7. The steps 14 and 15 correspond to the second ignition timing correction means.

When the control time TIM is limited to the predetermined time A or more in step 11, the process proceeds to step 5, the acceleration determination flag F is reset to 0, and the MAP advance value MADV retrieved in step 6 is set as the ignition timing. Control is performed. That is, during the predetermined time A, the acceleration determination after the acceleration determination is once prohibited, and then the prohibition is released and the ignition timing control based on the acceleration determination is restarted.

In this way, as shown by the solid line in FIG. 4, while the engine speed (average effective pressure) increased by acceleration begins to decrease, the ignition timing is previously retarded by a predetermined amount, and after the decrease begins, With the ignition timing corrected for the retard angle as an initial value, the control for advancing / retarding the ignition timing in a direction of suppressing the rotational fluctuation is started according to the amount of change in the rotational speed. Therefore, the ignition timing is advanced in the correction of the advance angle immediately after the rotation speed is lowered, so that the ignition timing is advanced in the direction approaching the optimum ignition timing of the torque priority.
The decrease in Pi can be effectively suppressed, and accordingly, the decrease in the engine speed at the initial stage of the swing back can be effectively suppressed, and the subsequent fluctuation in the rotation speed can be sufficiently suppressed. In the figure, the dotted line shows a conventional example. It is possible to correct the ignition timing in accordance with the rotational speed change amount immediately after the acceleration determination, but in this case, the retard correction amount may become too large, and a satisfactory acceleration feeling cannot be obtained. In this respect, in the case of the present invention, since the retard correction is performed by the amount set to suppress the swing back, the influence on the acceleration performance can be reduced.

If this retard correction amount is set according to the degree of acceleration (for example, it is detected by the changing speed of the throttle valve opening), the effect on acceleration performance can be sufficiently reduced regardless of the degree of acceleration, and the start of reversing At the same time, it is possible to secure an advance angle correction control amount (which can suppress the rotation decrease by the advance angle control) in the direction of approaching the optimum ignition timing depending on the degree of rebound, and always obtain a good rotation fluctuation suppressing effect.

Further, as shown by the chain line in FIG. 4, if the retard amount is gradually increased with a constant inclination for a predetermined time after acceleration is detected, the acceleration start ignition timing is not retarded with a step, and therefore the acceleration is accelerated. The feeling and acceleration performance can be better secured. Even in this case, the total retard amount after the predetermined time is constant (or the amount set according to the degree of acceleration), and the effect of suppressing the rebound is the same.

<Effects of the Invention> As described above, according to the present invention, since the ignition timing is retarded by the predetermined time after the acceleration is detected, the advance / retard correction is performed according to the rotation variation amount, so that the acceleration performance is secured. In addition, it is possible to effectively suppress the swingback and improve the riding comfort.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is an overall configuration diagram of an embodiment of the present invention, FIG. 3 is a flow chart showing a control routine of the same embodiment, and FIG. 3 is a time chart showing the state of each part in FIG. 1 ... Engine, 6 ... Air flow meter, 8 ... Throttle sensor, 10 ... Crank angle sensor, 11 ... Spark plug, 12
...... Ignition coil, 13 ...... Distributor, 20 ...... Control unit

Claims (1)

[Claims] 1. An engine operating state detecting means for detecting an operating state of an engine, a basic ignition timing setting means for setting a basic ignition timing based on the engine operating state detected by the operating state detecting means, and the operating state. Acceleration determination means for determining the acceleration state of the engine based on the engine operating state detected by the detection means, and timekeeping for measuring the elapsed time from the time when the acceleration determination means determines that the steady state has changed to the acceleration state. Means, first ignition timing correction means for correcting the basic ignition timing to a retarded side by a predetermined amount for a predetermined time after the start of measurement by the time measuring means, and after the predetermined time has elapsed after the start of measurement by the time measuring means,
A second ignition in which the ignition timing corrected by the first ignition timing correction means is used as an initial value, and the ignition timing is corrected according to the amount of change in a direction to suppress the engine rotation variation detected by the operating state detection means. A timing correction means; and an ignition signal output means for outputting an ignition signal to an ignition device at the ignition timing corrected by the first ignition timing correction means and the second ignition timing correction means. Ignition timing control device for internal combustion engine.