JPH0751930B2 - Ignition timing control device for internal combustion engine - Google Patents

Description

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 for an automobile, and more particularly to an ignition timing control device for suppressing shock during acceleration.

<Prior Art> In recent years, internal combustion engines for automobiles, particularly those equipped with an electronically controlled fuel injection device, provide fuel with a high response in accordance with the engine operating state, so that the engine is not operated during acceleration operation. The torque follows the change in the opening of the throttle valve with good responsiveness and rises sharply. Therefore, an acceleration shock occurs.

Further, since the vehicle has a large weight and a large inertia, it is not possible to follow the sudden output increase of the engine with good responsiveness. Therefore, when the vehicle shifts from the acceleration state to the steady state, the vehicle reciprocates (changes in the vehicle front-rear G). ), Jerky vibrations occur, and engine rotation fluctuations occur, which deteriorates drivability and riding comfort.

Therefore, when acceleration is detected based on the amount of change in the throttle valve opening, the ignition timing is corrected to a retarded side by a predetermined amount to suppress a rapid torque change, and the ignition timing is changed to the engine rotation for a predetermined time thereafter. It is proposed to correct the engine speed based on the amount of change in the number of rotations (that is, advance when the rotation is falling and retard when the rotation is increasing) to suppress the rotation fluctuation. (See Japanese Patent Application No. 62-70439).

<Problems to be Solved by the Invention> However, in the ignition timing control device for acceleration as a measure against such an acceleration shock, the basic ignition determined by the map using the engine speed and the load as parameters of the engine operating state. The timing is almost the best ignition timing (MBT),
Although the combustion pressure cannot be raised even if the ignition timing is advanced from the basic ignition timing, there is a problem in that the advance margin is increased and the ignition timing is advanced from the basic ignition timing, rather causing knocking.

In view of such problems, an object of the present invention is to make it possible to more appropriately perform the ignition timing control as an acceleration shock countermeasure while canceling an unnecessary advance angle to prevent knocking. And

<Means for Solving Problems> Therefore, according to the present invention, as shown in FIG. 1, an engine operating state detecting means for detecting an engine operating state including an engine speed, a load, and a throttle valve opening, Basic ignition timing setting means for setting a basic ignition timing based on the engine operating state detected by the engine operating state detecting means, and acceleration based on a change amount of the throttle valve opening detected by the engine operating state detecting means. Acceleration determining means for detecting the start, timing means for measuring the elapsed time from the time when the acceleration determining means detects the start of acceleration, and the retard angle side until the first predetermined time elapses from the acceleration start based on the timing means. First acceleration correction amount setting means for setting an acceleration correction amount, and the engine operating state detection means based on the time counting means until a second predetermined time elapses after a first predetermined time elapses. Second acceleration correction amount setting means for increasing / decreasing the acceleration correction amount in the direction of suppressing the fluctuation of the detected engine speed, and setting of the acceleration correction amount to the advance side by the second acceleration correction amount setting means. The acceleration correction amount advance side limiting means for limiting the value to a predetermined value and the basic ignition timing set by the basic ignition timing setting means.
And an ignition timing correction means for performing correction with the acceleration correction amount set by the second acceleration correction amount setting means, thereby configuring an ignition timing control device for coping with acceleration shock.

<Operation> When the acceleration determination means detects the start of acceleration based on the amount of change in the throttle valve opening, the first time until the first predetermined time elapses from the start of acceleration under the control of the time measuring means.
The acceleration correction amount setting means sets the acceleration correction amount to the retard angle side, whereby the ignition timing is corrected to the retard angle side from the basic ignition timing, the torque increase becomes relatively gentle, and the acceleration shock is prevented. . After the lapse of the first predetermined time, the second acceleration correction amount setting means rotates the engine toward the advance side in accordance with the change in the engine speed, that is, when the engine is descending, until the second predetermined time elapses. When rising, the acceleration correction amount is set on the retard side, whereby the ignition timing is appropriately corrected and rotation fluctuation is prevented. At this time, the acceleration correction amount advance side limiting means limits the setting of the acceleration correction amount to the advance side to a predetermined value, which limits the correction of the ignition timing to the advance side and causes knocking. Is prevented.

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

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.

The intake duct 3 is provided with a hot-wire type air flow meter 6 to detect the intake air flow rate. The throttle chamber 4 is provided with a throttle valve 7 that works in conjunction with an accelerator pedal (not shown) 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 controlled to a predetermined pressure by a pressure regulator fed from a fuel pump (not shown) to the engine 1.

The control of the fuel injection amount is calculated based on the intake air flow rate Q detected by the air flow meter 6 in the microcomputer incorporated in the control unit 20 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 to be stored, and the final fuel injection amount Ti = Tp · COEF + Ts (COEF
Is a correction coefficient including an acceleration correction coefficient and Ts is a voltage correction amount), and a drive pulse signal having a pulse width corresponding to Ti is given to the fuel injection valve 9 at a predetermined timing synchronized with the engine rotation.

A spark plug 11 is provided in each cylinder of the engine 1, and a high voltage generated in an ignition coil 12 is sequentially applied to these cylinders via a distributor 13, whereby fireworks are ignited 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.

For this ignition timing control, the engine speed N calculated based on the signal from the crank angle sensor 10 as a parameter of the engine operating state, and the basic fuel injection amount calculated as described above to represent the load Tp and are used. Further, the throttle valve opening TVO detected based on the signal from the throttle sensor 8 is used.

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

The microcomputer in the control unit 20 performs arithmetic processing according to the ignition timing control routine shown as a flowchart in FIGS. 3 and 4 to control the ignition timing (ignition advance angle) ADV.

The ignition timing control routine of FIG. 3 is executed every predetermined time. As a premise of this routine, although omitted in the flowchart, the throttle valve opening TVO
_Is detected, the previous value is stored as TVO _oLd , and then the current value
Stored as TVO _new and the amount of change in throttle valve opening Δ
TVO = TVO _new −TVO _oLd is calculated. Further, the engine speed N is detected, the previous value is stored as N _oLd , the current value is stored as N _new , and the engine speed change amount ΔN =
N _new −N _oLd is calculated.

In step 1 (denoted as S1 in the figure; the same applies hereinafter), the value of the acceleration determination flag F ₁ is determined. If F ₁ = 0 (before acceleration determination), the process proceeds to step 2 and the throttle valve opening degree Acceleration determination is made as to whether or not the change amount ΔTVO is equal to or greater than a predetermined value. The step 2 corresponds to the acceleration determining means.

If ΔTVO <predetermined value and acceleration is not determined,
From step 2 to step 3, the acceleration correction amount DLTADV is set to zero.

Then, the routine proceeds to step 22, where the basic ignition timing MADV is set by searching with reference to the map based on the engine speed N and the basic fuel injection amount Tp. The step 22 corresponds to the basic ignition timing setting means.

Then, the routine proceeds to step 23, where the acceleration correction amount DLTADV (DLTADV = 0 in this case) is added to the basic ignition timing MADV to calculate the final ignition timing ADV, and this routine is ended. This step 23 corresponds to the ignition timing correction means.

If ΔTVO ≧ predetermined value and acceleration start is detected, the process proceeds from step 2 to step 4 and the acceleration determination flag
F ₁ is set to 1, and then the process proceeds to step 5 to start the timer TIM as a time measuring means.

Then, the routine proceeds to step 6, where the retard angle amount TRADV (negative value) is set by searching according to the acceleration level by referring to the map based on the variation amount ΔTVO of the throttle valve opening at the time of acceleration determination. Further, the process proceeds to steps 7 and 8 to set the time coefficient KDADV to 1 and the phase control amount DNADV to 0.

Then, the routine proceeds to step 17, where the acceleration correction amount DLTADV is calculated according to the following equation.

DLTADV = TRADV · KDADV + DNADV In this case, since KDADV = 1 and DNADV = 0, DLTADV = TRADV (negative value).

Then, the process proceeds to step 18, but since DLTADV ≦ 0, the process proceeds to steps 22 and 23 as it is, the ignition timing ADV is determined, and this routine is finished. Therefore, the ignition timing AD in this case
V is the basic ignition timing MADV corrected to the retard side by TRADV.

When this routine is executed after the acceleration determination (that is, after the acceleration determination flag F ₁ becomes 1), the process proceeds to step 9 by the determination of the value of the acceleration determination flag F _{1 in} step 1.

Step comparison 9 the value of the timer TIM and a first predetermined time T _1, as if TIM <T ₁ (i.e. first predetermined time T ₁ from the start of acceleration) Step 17,18,22,23 Go to.

Therefore, the acceleration correction amount is corrected to the retard side by TRADV until the first predetermined time T ₁ has elapsed from the start of acceleration. Here, steps 6, 7, 8, 9, and 17 correspond to the first acceleration correction amount setting means.

When the first predetermined time T ₁ has elapsed from the start of acceleration, the process proceeds from step 9 to step 10 to compare the value of the timer TIM with the second predetermined time T _2, and TIM <T ₂ (that is, from the start of acceleration to the first If the second predetermined time T _{2 has} elapsed after the predetermined time T _{1 has} passed, the process proceeds to step 11. In step 11, the time coefficient KDADV is 0
If it is not 0, the time coefficient KDADV (initial value 1) is decreased by a predetermined amount in step 12.

Then, the routine proceeds to step 13, where the value of the phase control start flag F ₂ is determined, and if F ₂ = 0 (before the start of phase control), the routine proceeds to step 14 where the engine speed change amount ΔN becomes negative (That is, the engine speed has begun to decrease), and Δ
If N ≧ 0, the process proceeds to steps 17, 18, 22, and 23.

Therefore, after the elapse of the first predetermined time T ₁ , the acceleration correction amount DLTADV = TRADV · KDADV (however, KD
ADV: 1 → 0), and the ignition timing ADV gradually approaches the basic ignition timing MADV.

If ΔN <0 in the determination in step 14, the process proceeds to step 15 to set the phase control start flag F ₂ to 1 and then proceeds to step 16 to start the phase control.

Further, when the phase control start flag F ₂ is set to 1, the process proceeds to step 16 from the next time based on the determination of the value of the phase control start flag F ₂ in step 13, and the phase control is performed.

The control contents of the phase control are shown in FIG.
The positive / negative of ΔN is judged with, and if ΔN <0 (rotational drop), the process proceeds to step 32, and it is determined whether or not the time coefficient KDADV is 0. = K2X · (−ΔN), and if it has already become 0, proceed to step 34, and the phase control amount DNADV = K2Y · (−
ΔN). K2X and K2Y are constants. Also, step 3
If ΔN ≧ 0 (rotation increase) in the judgment in 1, step 3
After setting the time coefficient KDADV to 0 in step 5, the process proceeds to step 36 to set the phase control amount DNADV = −K1 · ΔN. K1 is a constant.

Therefore, at the time of rotation descent, the phase control amount DNADV is a positive value for correction to the advance side (however, the positive value is due to K2X, and if K2Y is set to K2Y = 0, so DNADV =
It becomes 0. ), When the rotation is increased, the phase control amount DNADV becomes a negative value due to the correction to the retard side.

When the phase control amount DNADV is set in this way, the process proceeds to step 17, and the acceleration correction amount DLTADV is set based on this.

Then, proceed to step 18 and set the acceleration correction amount DLTA
Whether the DV is positive or negative is judged, and if DLTADV> 0, the setting to the advance side is restricted for the purpose of preventing knocking, so the routine proceeds to step 19 and DLTADV = 0.

Then, the routine proceeds to steps 22 and 23 to calculate the ignition timing ADV based on the acceleration correction amount DLTADV.

Thus, until the second predetermined time T ₂ elapses, the ignition timing ADV is controlled to the advance side so that it approaches the basic ignition timing MADV when the rotation is decreased, and the ignition timing ADV is controlled to the retard side when the rotation is increased. The rotation fluctuation is suppressed.

Here, steps 9 to 17 correspond to the second acceleration correction amount setting means, and steps 18 and 19 correspond to the acceleration correction amount advance side limiting means.

When the second predetermined time T ₂ has elapsed from the start of acceleration, the step
After proceeding from 10 to step 20, the acceleration determination flag F ₁ and the phase control start flag F ₂ are both set to 0, then proceeding to step 21, the acceleration correction amount DLTADV is set to 0, and proceeding to steps 22 and 23, ignition timing ADV Determine. This returns to normal control.

FIG. 5 shows the state of the ignition timing control at the time of acceleration.
In addition, in this figure, the advance angle of the portion (a) is limited. In addition, the part (b) is set to K2Y = 0 and the advance angle is limited.

<Effects of the Invention> As described above, according to the present invention, in the ignition timing control at the time of acceleration according to the rotation fluctuation for the acceleration shock countermeasure,
The effect that the unnecessary advance angle is canceled and knocking can be prevented is obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is a system diagram showing an embodiment of the present invention, FIGS. 3 and 4 are flow charts showing control contents, and FIG. 5 shows control characteristics. It is a time chart. 1 ... Engine, 6 ... Air flow meter, 7 ... Throttle valve, 8 ... Throttle sensor, 9 ... Fuel injection valve, 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 engine operating state including an engine speed, a load and a throttle valve opening,
Basic ignition timing setting means for setting a basic ignition timing based on the engine operating state detected by the engine operating state detecting means, and acceleration based on a change amount of the throttle valve opening detected by the engine operating state detecting means. Acceleration determining means for detecting the start, time measuring means for measuring the elapsed time from the time when the acceleration determining means detects the start of acceleration, and delay angle side until the first predetermined time has elapsed from the start of acceleration based on the time measuring means. First acceleration correction amount setting means for setting an acceleration correction amount, and the engine operation state detection means based on the time counting means until a second predetermined time elapses after the first predetermined time elapses. Second acceleration correction amount setting means for increasing / decreasing the acceleration correction amount in a direction of suppressing fluctuation of the engine speed, and setting of the acceleration correction amount to the advance side by the second acceleration correction amount setting means are provided. The acceleration correction amount advance side limiting means for limiting the value to the value and the basic ignition timing set by the basic ignition timing setting means are corrected by the acceleration correction amount set by the first and second acceleration correction amount setting means. An ignition timing control device for an internal combustion engine, comprising: an ignition timing correction means.