JPS58158374A - Ignition timing controlling apparatus for internal-combustion engine - Google Patents

Abstract

PURPOSE:To prevent drop of the engine output, by controlling the ignition timing back to the reference ignition timing promptly after completion of delaying the ignition timing for rapid acceleration. CONSTITUTION:A circuit 7 for delaying the ignition timing at the time of acceleration detects the pressure in an intake mainfold and gives a pulse synchronous with the output pulse of a comparator 4 to an integrator 5 for a prescribed while after detecting acceleration. A capacitor 56 of the integrator 5 is charged rapidly in response to the output pulses of the comparator 4 and the circuit 7. Resultantly, the ignition timing is delayed rapidly, so that occurrence of knocking can be prevented. On the other hand, a comparing means 135 of a circuit 13 for releasing the ignition timing delaying control compares the output voltage of the integrator 5 with a reference voltage and detects arrival of the ignition timing. If the ignition timing does not come yet, the capacitor 56 is discharged rapidly by a transistor 182. Therefore, the ignition timing can be advanced promptly to the reference ignition timing, so that the lowering of the engine output can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition timing control device for an internal combustion engine.

The ignition timing of an internal combustion engine is set in such a way as to provide the best efficiency for the operating conditions of the engine. In general, MBT (Minimum
um advance for Be5t Torqu
It is desirable to set the ignition timing so that it approaches e).

However, most of the ignition timing control devices that have been installed in the past are mechanical, and the ignition advance characteristics are not stable due to product variations or changes over time. Therefore, the actual ignition timing is set much later than the desired ignition advance characteristic described above in order to prevent knocking.

This worsens the efficiency of the institution. In addition, even if an ignition timing control device that does not vary or change over time is used, the knocking phenomenon is affected by the engine's intake air temperature, humidity, air-fuel ratio, etc., so under certain conditions, the ignition timing at which knocking does not occur can be determined. Even if the engine is set to 1, knocking may occur under different operating conditions.

Therefore, if knocking is detected and if knocking occurs, the ignition timing is retarded at a desired speed, and after the retardation ends, the ignition timing is advanced at a desired speed. Even if an error occurs in the ignition advance characteristics due to differences in operating conditions, the ignition timing can be adjusted so that knocking hardly occurs. When engine operation is steady or with gradual acceleration/deceleration, knocking control can be performed stably because there are no sudden changes in engine operating conditions, but during rapid acceleration, the air-fuel ratio and ignition timing suddenly change significantly. Therefore, knocking is extremely likely to occur, and the knocking intensity is also very large, making it difficult to quickly suppress knocking using normal control. Therefore, it is possible to prevent knocking during sudden acceleration by determining the operating state of the engine and increasing the retardation amount when knocking occurs, or by retarding the ignition timing in advance. However, although the ignition timing can be set close to the desired MBT during rapid acceleration, after the acceleration ends, the load on the engine becomes lighter than during the acceleration period, and the engine becomes stable. However, after the ignition control during acceleration is completed, the ignition timing is advanced by the advance characteristic of the ignition device, so it takes time to return to the reference ignition timing, and the ignition occurs later than the MBT. As a result, the engine had the disadvantage of being extremely wasteful in terms of output and fuel efficiency.

This invention does not depend on the retardation characteristics of the ignition system to change the ignition timing after the end of the retardation control during rapid acceleration, but instead quickly reduces the amount of retardation retarded during acceleration, and changes the ignition timing to the reference ignition timing. The purpose of this is to improve engine output and fuel efficiency by returning to

FIG. 1 shows an embodiment of the present invention. In the figure, (1) is an acceleration sensor that is attached to an engine and detects the vibration acceleration generated in the engine, and (2) is an acceleration sensor of the acceleration sensor (1). The filter suppresses noise components other than the knock signal from the output signal, and is composed of a frequency filter that blocks the passage of signals other than a specific frequency, a gate filter that blocks the passage of signals at a predetermined timing, and the like. (
3) is a noise level detector that detects the mechanical vibration noise level of the engine other than during knocking, and (4) compares the output voltage of the filter (2) and the output voltage of the noise level detector (3). A comparator that generates a knock detection pulse, (
5) integrates the output pulse of the comparator (4) and performs knocking! ! (6) is a detection switch that is activated by detecting the intake manifold pressure of the engine. (7) is an integrator (6) that generates an integral voltage according to the time when the switch (6) is short-circuited. ) is a phase shifter that retards the phase of the reference ignition signal according to the output voltage of the integrator (5).
) is a rotation signal generator that generates an ignition signal according to a preset ignition advance characteristic, and 01 is a rotation signal generator (9
) to obtain a reference ignition signal and at the same time control the closing angle of energization of the ignition coil @.This output is phase-retarded by the phase shifter (8). Ru. Oo is the ignition coil 0 due to the output signal of the phase shifter (8)
'4 is a switching circuit that cuts off the power supply, and (3) is a retard canceling circuit that reduces the output voltage of the thousand-one divider (bj) after the control of the acceleration retard circuit (7) is completed.

Figures 2 and 8 show operating waveforms with the same symbols as those in Figure 1. Figure 2 shows a mode in which engine knocking does not occur, and Figure 8 shows a mode in which engine knocking occurs. It shows.

Next, the operation of the embodiment shown in FIG. 1 will be explained.

The rotation signal generated by the rotation signal generator (9) in accordance with the ignition timing characteristics set in advance by the rotation of the engine is waveform-shaped into opening/closing pulses having a desired closing angle by the waveform shaping circuit 01), and the rotation signal is waveform-shaped into an opening/closing pulse having a desired closing angle. The switching circuit (b) is driven through (8) to intermittent the power supply to the ignition coil (2), and the engine is ignited and operated by the ignition voltage of the ignition coil (2) generated when the current is cut off. . Engine vibrations occurring during operation of the engine are detected by an acceleration sensor (1).

If engine knocking does not occur, engine vibration due to knocking will not occur, but due to other mechanical vibrations, the output signal of the acceleration sensor (1) will change as shown in Figure 2 (a).
As shown in , mechanical noise and ignition noise that rides on the signal transmission path occur at the ignition timing (p). These noises are suppressed by filter (2), and filter (2)
The output signal is as shown in (a) of FIG. 2(b). On the other hand, the noise level detector (3) responds to changes in the peak value of the output signal of the filter (2), and in this case, has a characteristic that it can respond to relatively gradual changes due to the peak value of the mechanical noise of conduction. , and generates a DC voltage slightly higher than the peak value of the production noise ((b) bleed in FIG. 2(b)).

Therefore, as shown in FIG. 2(b), the noise level detector (
Since the output of 3) is large, a comparator (
The output of 4) is shown in Figure 2 Cc) (nothing is output as shown in Q,
Eventually all noise signals are removed. Therefore, the integrator (6
) remains at zero as shown in FIG. 2(d), and the phase shift angle (phase difference between input and output) by the phase shifter (6) also becomes zero. Therefore, the intermittent phase of energization at 1° non-(c) of the ignition is in phase with the reference ignition signal output from the waveform shaping circuit αQ, and the ignition timing becomes the reference ignition position.

In addition, if knocking occurs, the acceleration sensor (1)
As shown in Fig. 8(a), the output of the ignition timing (F) includes a knock signal around a certain time later than the ignition timing (F), and the output of the filter (2)
) The signal after passing through the knock signal becomes a mechanical noise largely superimposed on the knock signal as shown in (a) of FIG. 3(b). Among the signals that have passed through this filter (2), the knock signal has a steep rise, so the response of the output voltage level of the noise level detector (3) to the knock signal is delayed. As a result, the two inputs of the comparator (4) become as shown in FIG. 8(b), so that a pulse is generated at the output of the comparator (4) as shown in FIG. 8(c). An integrator (li) integrates the pulse and generates an integrated voltage as shown in FIG. 8(d). Since the phase shifter (8) shifts the phase of the signal of the waveform shaping circuit (6) (FIG. 8(e)) to the delayed side according to the output voltage of the integrator (5), the phase shifter (8) ) is delayed from the phase of the reference point signal of the waveform shaping circuit αQ as shown in FIG. 8(f).

The switching circuit (b) is driven by the output of this delayed phase, and as a result, the ignition timing is delayed and the occurrence of knocking is suppressed. Furthermore, during rapid acceleration, conditions such as the engine's air-fuel ratio and ignition timing are unstable, so knocking is extremely likely to occur.・If the knocking condition continues as shown in the figure, it is not possible to immediately suppress the knocking. For this purpose, when the intake manifold pressure is detected and exceeds a predetermined pressure, a switch (6) is activated, and the acceleration retard circuit (7) is activated by the switch (6).
If knocking occurs by changing the charging time constant of the integrator (6), the output voltage of the integrator (5) will increase rapidly due to rapid charging, and as a result, the ignition timing will be significantly delayed, thereby eliminating the knocking immediately. can be suppressed to

However, even though the load on the engine after the end of the retard control during sudden acceleration (after the end of acceleration) is lighter than during the acceleration period, the advance angle return time determined in the steady state (Fig. 3 (d) )
), it takes time to return to the standard ignition timing. This causes problems such as a decrease in engine output and a decrease in fuel efficiency.

A method for solving this problem will be explained using a specific example shown in FIG. 4, including a rapid retardation operation during rapid acceleration.

Figure 4 shows the comparator (4), integrator (5), pressure detection switch (6), acceleration angle control circuit (7), and retardation release circuit (
This is an example of a circuit. In the figure, - is a diode, -m- is a resistor, - is a capacitor, (181) is a resistor,
(1 company) (lO) is a transistor \Qs4) is a flip-flop (hereinafter referred to as F, F), R is a reset terminal, S is a set terminal, and Q is an output terminal. Also, (185+ is a comparison device.

If knocking is not occurring now, the capacitor of the integrator (6) is not charged with anything because no knock signal pulses are output from the comparator (4).

Therefore, the ignition timing is set at the reference ignition timing.

Also, if knocking occurs during normal operation, the comparator (4
) the capacitor is charged only by the resistor via the diode. If knocking occurs during sudden acceleration, when the intake manifold pressure reaches a predetermined pressure or a predetermined rate of change due to sudden acceleration, the pressure detection switch (6) activates the acceleration angle control circuit (7).
) to output a detection signal (Fig. 5(g)). The angle adjustment circuit (7) during acceleration operates for a certain period T1 (Fig. 6 (h)) from the time when the intake manifold pressure is detected (point
)) outputs a pulse synchronized with the output pulse from the comparator (4) to the integrator (6). Therefore, the capacitor of the integrator (5) is rapidly charged by the output pulse from the comparator (4) and the acceleration angle control circuit (7), and the voltage of the capacitor rapidly increases (6th Figure (d)
). For this reason, the ignition timing is far delayed to suppress knocking that occurs during sudden acceleration.

Next, the operation of the retard release circuit (f) to return the ignition timing to the expected ignition timing after the end of the retardation side during acceleration will be explained.

The comparator of the retard release circuit 0 compares the output voltage of the integrator (5) with the reference voltage (c) and detects that the ignition timing has reached the reference ignition timing. If the output voltage of the integrator (5) is higher than the reference voltage (c), the output becomes high 1/bell and drives the transistor (1), and if the voltage is lower than the reference voltage (c), it becomes low level and drives the transistor (1). Iu)
turn off. F, F, (When a pulse of 11 is input from the acceleration angle control circuit (7) to the R terminal of ta3,
Triggered by the falling edge, Q becomes low level and the transistor (188) turns off. Then, the integrator (5)
Since the output voltage of is high, the comparison device (old) is a transistor (
182), the capacitor is rapidly discharged by the resistor (181) and the resistor -, and the voltage of the integrator (5) decreases, so the ignition timing is quickly advanced to the reference ignition timing.

When the output voltage of the integrator (5) becomes equal to the reference voltage (c) due to rapid discharge (point Y in FIG. 5(d)), the comparator Qas) becomes a low level, and F, F.

(164) is set and the Q output becomes high level. As a result, the transistor (old) is on-state, the transistor (l
Since the capacitor (1111) is turned off, the rapid discharge of the capacitor that was being performed by the resistor (1111) stops. As described above, the retard release circuit (2) operates during the - period shown in Fig. 6, and the integrator (
6) Rapidly reduce the output voltage. After this period T2, the normal knock control returns and the acceleration angle control circuit (7) returns to normal knock control.
It will remain in a stopped state until it is activated.

In the above embodiment, the retard release surface 'Ilf! In the operation of α3,
Although the method of detecting the output voltage of the integrator (5) has been adopted, a timer having a fixed time width after the output pulse T1 of the angle adjustment circuit (7) during acceleration ends may be used.

As described above, the retard release circuit (to) shortens the discharge time constant of the integrator (5), thereby reducing engine waste that would occur before returning to the reference ignition timing due to the advance characteristics of conventional devices. It becomes possible to eliminate the problem. .

In the above embodiment, the intake manifold pressure was detected and the processed signal was used to activate the retard release circuit. It is possible to detect acceleration by the method.

As explained above, the present invention promptly returns the ignition timing to the reference point large timing after the end of the retardation control during sudden acceleration.
The reduction in engine output that occurred during the advance time of conventional equipment,
This has the effect of minimizing the decrease in fuel consumption.

[Brief explanation of the drawing]

The first factor is a block diagram showing the +3 configuration of the Ichijo embodiment of this invention, Figures 2 and 3 are waveform diagrams showing the operating status of each part in Figure 1, and Figure 4 is the main part of Figure 1. A circuit diagram showing the specific direction, and FIG. 5 is a waveform diagram showing the operating state of each part of FIG. In the figure, (1) is an acceleration sensor, (2) is a filter,
(3) is a noise level detector, (4) is a comparator, (5)
is an integrator, (6) is a switch >'-, (7) is an angle steering circuit during acceleration, (8) is a phase shifter, (9) is a rotation (in "5-generator), Qo is a waveform shaping circuit, (b) is the switching circuit, υ is the ignition coil, and (2) is the retard release circuit. In addition, the same reference numerals in the figures indicate the same or equivalent parts. Agent Makoto Kuzuno - 4th diagram L g I1 - Darkness

Claims (1)

[Scope of Claims] (]) Knocking detection means for detecting a knocking state of the internal combustion engine, reference ignition timing signal generation means for generating a reference ignition timing signal, and the reference ignition timing signal according to the output of the knocking detection means a phase shifter for retarding the phase of the phase shifter, a switch means for switching on and off the power supply to the ignition coil in synchronization with the output of the phase shifter, and an acceleration retardation means for operating the phase shifter when the engine accelerates. An ignition timing control device for an internal combustion engine, comprising: a retard release means for canceling the retard operation by the acceleration retard means. (2) The ignition timing control device for an internal combustion engine according to claim 1, wherein the retard release means includes at least a level comparison or a timer.