JPS58155283A - Ignition timing control device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To perform acceleration smoothly by judging as an acceleration state when multiple knocks occur in succession at a short interval to increase the spark advance speed and by judging that a stationary state is attained based on the subsequent spark advance state and knock sensor information to decrease the spark advance speed. CONSTITUTION:An ignition time control circuit 8 consisting of a microcomputer judges as an acceleration state when multiple knocks occur at a short interval to increase the spark advance speed, because in a stationary state knocks due to signals 7 occur at a long interval and multiple knocks do not occur in succession, even if at a short interval. The spark advance target value is made the basic ignition time based on the base map, but the knock limit ignition time of the stationary state is passed before the target ignition time is attained, thus generating a knock signal 7. Therefore, if the spark advance speed is decreased when a knock occurs or a predetermined number of knocks occur, a stable control condition under the stationary state can be smoothly attained. It is further effective to delay the starting time to increase the spark advance speed a little, because knocks in the acceleration pass reliably during the delay.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of an ignition timing control device (iJ, knock control system, !4P) that has a function of detecting engine knock and advancing and retarding the ignition timing. be.

In recent years, various knock control systems have been studied that detect knock occurring in an engine and advance the ignition timing by half an angle in accordance with the state of the knock.

By using this knock control system, the ignition timing can always be controlled near the knock limit, thus maximizing the engine's fuel efficiency and output performance without being affected by engine variations or aging rates. I can do it.

However, the conventional knock control system has a serious problem in that acceleration failure occurs when the engine accelerates. In other words, this is a sluggish acceleration that occurs after the ignition timing is significantly retarded due to knocks that occur continuously immediately after acceleration.

This occurs because the required ignition timing changes rapidly during transient conditions, especially during rapid acceleration, and the advance operation speed of the knock control system cannot follow the change (8). It is generally known that the larger the amount of the averagely calculated DK advance angle per unit time or unit cycle (hereinafter referred to as advance angle speed), the better the followability during transient times will be. However, when the advance angle speed is increased, ignition timing fluctuations in steady state become larger, resulting in excessive torque fluctuations, and as a result, drivability in steady state deteriorates. Therefore, conventional knock control systems compromise between steady and transient conditions. : (for example, an advance angle speed of about 100 A/1 second), it was not possible to satisfy both steady and transient performance (particularly transient performance). Therefore, in order to fundamentally solve the sluggish acceleration, it is necessary to increase the advance angle speed only during acceleration and maintain a small advance angle speed during steady state.

One possible method for this is to determine the acceleration state by detecting the engine state (for example, rotational speed, main hold pressure, etc.) and change the advance angle speed in accordance with this result. However, since the engine knock condition and the ignition timing retardation (bleeding condition) are greatly affected by environmental conditions or changes over time, if acceleration is judged based on information from the engine conditions and the advance speed is carelessly increased, Even though the ignition timing is at the required ignition timing in a steady state, excessive knock often occurs repeatedly or torque fluctuations become excessive due to the rapid advance of the ignition timing. This is caused by manipulating the advance angle speed in a positive relationship with the angle state and the subsequent knock state or advance state.

In view of the above-mentioned problems, the present invention determines a knock occurrence pattern peculiar to acceleration based on whether the knock occurrence interval is shorter than a predetermined value for a plurality of consecutive times, and uses information from subsequent knock sensors or advance angle state. To provide an ignition timing control device which solves sluggish acceleration and improves drivability in a steady state by determining whether a steady state has been reached and increasing the advance angle speed only during that time.

The technical rationale of the present invention will be explained below. -! First, a method for determining acceleration from knock sensor information will be explained.

The biggest difference between the knock occurrence patterns between the steady state and the accelerated state is the frequency of knock occurrence. That is, during steady state, knocking occurs sporadically, so the frequency of knocking is low; on the other hand, during acceleration, knocking occurs frequently, so the frequency of knocking is high. Therefore, when looking at the time interval between knocks or the ignition cycle interval (hereinafter referred to as the knock occurrence interval), the knock occurrence interval is long in steady state;
It becomes shorter when accelerating. However, when this was studied in detail, it was found that even in a steady state, there are cases where the knock occurrence interval is short, and in this case, increasing the advance angle speed deteriorates the drivability in the steady state.

In connection with this, the present inventors have discovered that if the determination means is used to determine whether or not the knock occurrence interval is short several times, it is possible to accurately determine whether the vehicle is accelerating or not. In other words, although the knock interval may be short during steady state,
It was discovered that there were no cases where this occurred multiple times in a row, and such cases only occurred during acceleration.

Of course, judging from the engine conditions, even if the engine is in an accelerating state, if knocks do not occur very frequently due to m-environmental conditions, etc., the present invention determines that it is not accelerating, but in this case, the advance angle speed should be increased. The present invention makes sense because there is no need to do so.

Next, a method for decreasing the advance angle speed when a steady state is reached after increasing the advance angle speed will be described. First, if the advance angle speed increases after acceleration, the target value of the advance angle is
Basic ignition timing determined by the base map of the distributor or microcomputer (i.e., ignition timing with 0 retardation amount by the knock control system) or ignition timing slightly delayed from the basic ignition timing (i.e., ignition timing with retardation amount of a predetermined amount α) period) is good.

Alternatively, the ignition timing may be advanced by a predetermined angle after the advance speed increases. However, in many cases
Before advancing to the target ignition timing, the knock limit ignition timing in steady state is passed, so knocking occurs. Therefore, by reducing the advance angle speed at the time when a knock occurs or at the time when a predetermined number of knocks occur, it is possible to smoothly shift to a stable control state at a steady state.

Further, the effect will be further improved if the timing at which the advance angle speed starts to increase is slightly delayed (by a predetermined time or by a predetermined time /I/) from the time when the knock occurrence pattern satisfies the above-mentioned conditions. This is because the knock during acceleration will definitely pass during the delay, and therefore the knock that occurs after the advance angle speed increases is definitely the knock during steady state.

Hereinafter, the present invention will be explained with reference to embodiments shown in the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

In Fig. 1, l is a 4-cylinder 4-cycle engine, 2 is an air cleaner, 3 is an air flow meter that detects the intake air amount of the engine and outputs a signal according to this, 4 is a throttle valve, and 5 is a reference crank angle of the engine. This is a distributor that incorporates a reference angle sensor 5B for outputting the position (for example, top dead center) of 4* and a crank angle sensor 5B for generating an output signal at every fixed crank angle of the engine.

6 is a knock sensor for detecting the vibration of the engine block corresponding to the engine knock phenomenon using a pressure element type (piezo element type), electromagnetic type (magnet, carp/1/1/2), etc.; 7 is the output of the knock sensor; This is a knock detection circuit for detecting the occurrence of engine knock. 9 is a water wetness sensor that generates a signal according to the wetness of the engine cooling water;
12 is a fully closed switch (eye, dollar switch) for outputting a signal when the slot/l/valve 4 is fully closed.
, 13 is a full open switch (power switch) for outputting a signal when the throttle valve 4 is almost fully open;
14 is a 0° sensor that generates an output signal depending on whether the air-fuel ratio (A/F) of the exhaust gas is richer or leaner than the stoichiometric air-fuel ratio.

Reference numeral 8 indicates a control circuit for controlling the ignition timing and air-fuel ratio of the engine according to input signal states from each sensor and each switch. This is an igniter and ignition coil that turns off the current to the silane coil. The high voltage generated by the ignition coil passes through the power distribution section of the distributor 5 and ignites the spark plug of a predetermined cylinder at an appropriate time. Reference numeral 11 denotes an injector for injecting fuel into the intake manifold based on the fuel injection timing and fuel injection time (1) determined by the control circuit 8.

Next, the detailed configuration of the knock detection circuit 7 will be explained using FIG.

701 is a filter such as a bandpass or heibus for selecting and increasing only the knock frequency component of the output of the knock sensor 6; 702 is a half-wave rectifier mu for half-wave rectifying the output of the filter 701; and 708 is a half-wave rectifier. An integrator for integrating the output of the rectifier 702 and extracting the average vibration output of the knock sensor 6; 704 is an amplifier for amplifying the output of the integrator 708 to create an appropriate knock judgment level; 705 is an amplifier for the amplifier 704; An offset voltage setter 706 is composed of a resistor etc. that shifts the voltage in order to obtain effects such as noise margin on the output, and 706 is an offset voltage setter between the output of the amplifier 704 and the offset.
An adder 707 is a half-wave rectifier 70 for adding the output of the wake-up pressure setting device 705 to produce the final knock judgment rep.
2 and the output of the adder 706, and when the output of the half-wave rectifier 702 is larger, it is determined that a knock has occurred, and in that case, the comparator generates a pulse signal.

708 is a counter that calculates the number of pulses of this pulse signal and converts it into a binary parallel signal.
It is reset in synchronization with the ignition signal from 0. Reference numeral 709 denotes a code converter (encoder) that divides the parallel output of the counter 708 into cases according to the count tXK and converts it into a smaller number of connection lines.

The operation of this knock detection circuit will be explained using FIG.

In FIG. 3 (the field diagram is the output signal of the filter 701,
Of the output of the knock sensor 6, the knock i wave e component (6 to 9
This is a signal extracted by selecting only 1G(z). (a
In Figure 1, al + at + aZ represents outputs corresponding to three different (11) knocking states.

That is, al is a relatively small knock, al is a relatively large knock, and a3 is a noise or an extremely small knock. (b) shows the signal after half-wave rectification of (al) by the rectifier 702, (01 shows the signal after half-wave rectification of the (b1) by the integrator 708.
and the signal after being integrated and amplified by the amplifier 704. (Figure d1 is the signal after adding the offset voltage 705 to the figure (c) by the adder 706 (that is, the knock judgment level), and the output signal (mountain country) of the rectifier 702 is also drawn in the sense of a comparative solution. (Figure 01 shows the comparator 70
7, the output signal of the rectifier 702 (Figure (b))
If it is larger than the knock judgment level (figure (d)), it will be high (High), and if it is smaller, it will be low (L).
ow ) level.

Since the number of pulses of this pulse signal corresponds to the intensity of the knock (see the number of pulses for at and al), the knock intensity is converted into the number of pulses by counting the number of pulses with a counter 708. This counter 708 is reset in synchronization with the ignition signal (12), so that the intensity of one knock occurring for each ignition can be known for each ignition.

A parallel signal corresponding to the count value of this counter 708 is input to an encoder 709. Encoder is counter 70
The 8 counting units are classified into several groups and outputs according to the classification are sent to the control circuit 8. For example, if you use a 5-bit configuration as a counter and use two encoder output lines,
Counts ffO to 31 are classified into four groups. That is, 1·n reports of four classifications of knock intensity (no knock, small knock, medium knock, and large knock) are input to the control circuit 8. Due to the function of this encoder 709, the number of signal lines to the control circuit 8 can be significantly reduced, and the number of input ports of the control circuit 8 can be significantly reduced.

Next, the detailed configuration and operation of the control circuit 8 will be explained with reference to FIG. In Fig. 4, 8000 is a central processing unit (CPU) for calculating ignition timing and fuel injection amount.
It uses a bit-structured microprocessor. 800
1 is a read-only memory unit (ROM) for storing control programs and control constants necessary for calculations;
8002 is a temporary storage unit (which is used to temporarily store calculation data while the 0PU8000 is operating according to a program).
RAM). 8008 is a waveform shaping circuit for shaping the waveform of the magnetic pickup signal which is the output signal of the reference angle sensor 5M, and 8004 is a waveform shaping circuit for shaping the waveform of the output signal of the crank angle sensor 5B.

8005 is 01"U by external signal or internal signal.
An interrupt control unit 8006 for causing the CPU to perform interrupt processing is a 16-bit timer configured to increment its count value by one every clock cycle, which is the basic cycle of CPU operation. This timer 8006 and interrupt control unit 8005
The engine speed and crank angle position are input to the CPU in the following manner. That is, the CPU reads the count value of the timer every time an interrupt occurs due to the output signal of the reference angle sensor 5m. Since the count value of the timer increases every clock cycle (for example, lμs), by calculating the difference between the count value at the time of the current interrupt and the count value at the previous interrupt, the reference angle sensor signal The time interval, that is, the time required for one revolution of the engine can be measured. In this way, the engine speed is determined. Further, the crank angle position is determined by the crank angle ((3A)) based on the top dead center signal of the reference angle sensor 5A, since the signal of the crank angle sensor 5B is output at every fixed crank angle (for example, 30°OA). This crank angle signal every 808 cm is used as a reference point for generating the ignition timing control signal.

8007 is a multiplexer for timely switching multiple analog signals and guiding them to an analog-to-digital converter (A/D converter) 8008, and the switching timing is determined by the output board 80.
It is controlled by multiple control signals in addition to the control signals output from 11. In this embodiment, the intake air amount signal from the air flow meter 8 and the water wetness sensor 9 are used as analog signals.
A water-wetting signal is input from the 8008 is an A/D converter for converting an analog signal into a digital signal.

(15) 8009 is an input board for digital signals, and in this embodiment, this port receives a knock signal from the knock detection circuit, an idle signal from the idle switch 12,
Power signal from power switch 13, 02 sensor 14
A rich lean signal is input from

801O is an output port for outputting a digital signal. An ignition timing control signal for the igniter 10, a fuel injection control signal for the injector 11, and a control signal for the multiplexer 8007 are output from this output port. 8011 is a 3PU bus, and the CPU carries control signals and data signals on this bus signal line to control peripheral circuits and send and receive data.

Next, a method of calculating the ignition timing will be explained. 5 to 7 are flowcharts showing an example of an ignition timing calculation method. The process will be explained below using this flowchart. In FIG. 5, first, the rotation speed N and load (Q/N) are determined from the signals from the reference angle sensor and air flow meter. Here, Q is the amount of intake air output from the airflow meter, and the load applied to the engine is 1it (Q/N), which is Q divided by the engine speed N.

Furthermore, in this embodiment, the rotational speed N is measured using a beam angle sensor, but if the processing capacity of the microcomputer is sufficiently high, a crank angle sensor may also be used. The basic ignition timing θB stored in the memory is calculated based on the load (Q/N) and the load (Q/N). This basic ignition timing θ
B is stored in memory as a two-dimensional map of N and Q/N.

Next, if the load Q/N is smaller than a predetermined value, it is determined that the load is light so that knocking does not occur, and the process branches to (2) in FIG.

If the load is not light, then it is determined whether the current combustion cycle is a knock cycle based on the output from the knock detection circuit. If no knock occurs, the process branches to ■ in FIG. If a knock occurs, the retard amount Δθ is set according to the intensity of the knock. (For example, for a small knock, Δθ = 0.5°OA, for a medium knock, Δθ-1°
(For a large knock of 3A, Δθ = 1.5°OA) The retardation amount Δθi for each knock intensity (for example, Δθ, = 0.5°CA)
.

Δθ2=l'OA, Δθ3=1.5°OA) is ILOM
is stored as a constant in . Next, it is determined whether the knocking interval is longer or shorter than a predetermined interval (for example, 4 cycles). This knock occurrence interval can be known by reading the value of the cycle counter C allocated in the RAM. In other words, the counter on this software is cleared to 0 as soon as a knock occurs, and functions to count the ignition cycles until the next knock occurs. This counter counts up (up) to a predetermined value [Oo]
The program is then programmed to retain that information. This is to prevent counter overflow.

Now, when the knock occurrence interval is long, the continuous counter CC on the software is reset to O, and when it is short, conversely, the continuous counter CC is incremented by 111 and the retard amount Δθ is corrected. Here, continuous counter CC
is a counter for determining how many times the knock occurrence interval is short. Further, the reason why the retardation amount Δθ is corrected when the knock occurrence interval is short is to greatly retard the angle during acceleration to enhance the effect of suppressing knock noise during acceleration. For example, by amplifying the retardation amount Δθ by two times (γ-2)
The noise reduction effect during acceleration is significantly improved. Next, the total amount of retardation from the basic ignition timing, that is, the corrected ignition timing θC is determined (θC=θC−Δθ). An upper limit θCmaK is set for this corrected ignition timing θC, and it functions as a limiter that prevents the ignition timing from being retarded any further.Then, the final ignition timing θ for the next ignition is calculated from θ-θB-θC, and Set the timer to 7 points. Next, the acceleration advance angle force Quantum C1 delay counter D, which is a counter on the software.
C1 Steady advance angle counter A and cycle counter C are all cleared to O.

Next, it is checked by the acceleration advance angle flag whether or not the advance angle speed is currently increasing. This acceleration advance angle flag remains ON (ON) only while the advance angle speed is increasing. If this flag is ONI, and therefore the advance angle speed is increasing, the knock count (19) is counted up by one NO. This knock counter KC is a software counter for determining how many knocks have occurred after the advance angle speed has increased.

When the value of this knock counter K (3) reaches a predetermined value [K (3o (for example, xco = 1, or For this purpose, turn off the acceleration advance angle flag and delay flag, and reset the knock counter to θ.After that, or when the acceleration advance angle flag is off, the next step is to check the value of the continuous counter CC.Continuous counter When CC reaches the predetermined value CC3 (00o?2), it is determined that the time is accelerating because short knock occurrence intervals have occurred continuously, and preparations are made to increase the advance angle speed.In other words, the delay flag is set. Turn it on and return to the main program.

Now, the calculation method when the current cycle is not a knock cycle will be explained using FIG. In FIG. 6, first check whether the acceleration advance angle flag is ON or OFF (20). When ON, the acceleration advance angle counter AC is counted up by one in order to carry out advance angle operation at a large advance angle speed for acceleration. This counter AC is a software counter that repeatedly counts from O to a predetermined UIACot. AC is at a given II AQI (e.g. 2 cycles/I
/), the current corrected ignition timing OC is maintained as it is. If AC3G has been reached, the counter AC is increased by seven and a predetermined angle 0mmC (for example, 0.5°OA) is decreased from the corrected ignition timing θC. Therefore, the ignition timing is advanced by θAC. Fixed. In this way, when knock does not occur and the acceleration advance angle is executed (in this example, 0.5 times every two cycles (AC6=2))
The advance angle is rapidly advanced in steps of °OA (θ = o, 5 °CA). Next, when the corrected ignition timing θC becomes negative, this value is corrected to O and the acceleration advance flag and delay flag are turned OFF. This prevents the ignition timing from advancing beyond the basic ignition timing 03, and when the basic ignition timing θB is reached (that is, when the retardation amount due to knock control is 0C = 0), the advance speed is reduced to a small value of 1. This is to bring it back.

Now, in step Φ in FIG. 6, if the acceleration advance angle flag is OFF, the delay flag is turned ON.

Check OFF. When the delay flag is ON, it is a preparation period for increasing the advance angle speed. In other words, the current corrected ignition timing is maintained until the delay counter DO reaches a predetermined MDCo (for example, 4 cycles), and when the delay counter DO reaches the predetermined value DOo, the acceleration advance flag is turned ON to initiate the rapid advance process described above. enter. Therefore, in the case of this embodiment, rapid advance starts after a delay of four cycles.

Further, when the 1@advance flag is OFF, a small advance rate for steady state is used as the advance angle speed, and this counter for steady advance angle is the steady advance angle power rantum. This counter A counts up by one for each non-knock cycle μ, and is reset at each knock cycle.

This counter A is set to a predetermined value M0 (for example, 30 cycles/
L/), the corrected ignition timing θC is set to a predetermined value θA.
(for example, 0.5°OA) in the advance direction (θ
C-θC-θm). Therefore, in this embodiment, the advance angle during steady state is corrected by 0.5° (A) every 30 cycles.The corrected ignition timing θC must not be negative in the same way as the advance angle during acceleration. In the case of a non-knock cycle, the ignition timing θ is corrected in the advance direction as shown below.Then, this field (θ-θB-○C) is set in the timer and the ignition countdown begins. after that,
The cycle count C is counted up by one and the process returns to the main program.

Now, the calculation method in the case of light load will be explained using FIG. If the load is light, set the delay flag and acceleration advance angle flag to O.
By FF, the advance angle speed is returned to the small speed for steady state. and various counters (acceleration advance angle counter, etc.)
and reset or initialize the corrected ignition timing θC.
Set to O.

In this case, the ignition timing θ becomes equal to θB, resulting in the most advanced state. This is to prevent performance loss due to retardation by quickly changing to the most advanced position when the load is light.

(23) The ignition timing is calculated as described above, and the engine is ignited through the igniter and coil.

Next, FIG. 8 shows the ignition timing control state when the present invention is used. The horizontal axis shows the progress of the ignition cycle, and the vertical axis shows the corrected ignition timing θC (that is, the total retardation amount due to the knock control p−μ). In FIG. 8, l is the present invention,
2 represents the conventional ignition timing control state. Furthermore, sections a, b, and c in the present invention are delay sections, respectively.
It represents the acceleration advance angle section and the steady advance angle section. It can be seen that the present invention returns to the knock limit ignition timing in a steady state more quickly than the conventional method. As a result, sluggishness during acceleration is eliminated and good acceleration performance is obtained. Also, since the knock occurred at the end of the section, the advance angle speed returned to the steady state, and as a result, steady state stability was ensured.

In this embodiment, the retardation amount Δθ per knock is changed depending on the knock intensity and the knock occurrence interval, but it is also possible to change only one of them or not change it at all. In this case, (24) is the strength determination part (counter 7) in the knock detection circuit 7.
08 and encoder 709) are no longer necessary.

That is, since it is only necessary to check whether there is a knock, a latch, a flip-flop, or the like may be used instead of the counter 708 and encoder 709.

Further, in this embodiment, the detection of the knock occurrence interval, the count-up of the advance angle counter, the delay counter, etc. are performed as the ignition cycle progresses, but any or all of these may be performed in units of time. For example, the function of the timer 8006 in FIG. 4 may be used.

Furthermore, in this embodiment, before increasing the advance angle speed, the increase in speed is delayed for a certain period of time, but this is not necessarily necessary. However, it is more effective if it is delayed.

In addition, in this embodiment, the advance target value after increasing the advance speed is set to the basic ignition timing θB (that is, the total amount of retardation due to knock O), but the ignition timing is retarded by a certain angle βOOA than θB (θL -β), or the ignition time may be set to 19](θC-γ), which is advanced by a predetermined angle roOA from the current daughter #4 angular amount θC.

Alternatively, past retard amounts may be stored in a memory, and the stored retard amounts may be used as the target ignition timing. In addition,
In these cases, when the ignition timing when the advance angle speed is increased is on the advance side than the target ignition timing, the increase in the advance angle speed may be disabled.

Further, in FIG. 8, the advance angle speed is decreased when one knock occurs after increasing the advance angle speed, but it may be decreased when knocks occur a predetermined number of times, which is two or more times. In this case, the advance angle speed may be decreased little by little each time a knock occurs, and the advance angle speed may be completely returned to a small initial value when knocks have occurred a predetermined number of times.

Moreover, even more fine-grained control can be achieved by changing constants such as the threshold value C8 of the knock occurrence interval in accordance with engine conditions such as engine speed or load.

Further, in this embodiment, the basic ignition timing OB is determined from a map in the memory, but it may also be determined by a governor and a vacuum adpanser in the distributor.

Furthermore, in this embodiment, the signal after the knock determination by the knock detection circuit is input to the microcomputer, but the knock determination may also be made within the microcomputer.

For example, a peak hold circuit extracts the largest chain of output signals from a knock sensor and converts this peak hold signal into an A/D.
You can also convert it and input it to the microcontroller.

The knock judgment level in this case can be created by numerically averaging the peak hold signal over many cycles.

Furthermore, in this embodiment, the number of ignition cycles (or holding time) to maintain the same ignition timing is changed in order to change the advance speed. The advance angle amount may be changed. (For example, set the acceleration advance angle to 3°OA/80 ignitions, and the steady advance angle to 10Cum/30 ignitions, etc.) Of course, both the number of ignition cycles (or retention time) to be held and the amount of advance angle per cycle are set. You can change the advance angle speed by changing (
27) It is more effective. The acceleration advance angle is
This is because if the number of ignition cycles to be held (or the holding time) is reduced and the amount of advance per cycle is made slightly smaller to advance the engine smoothly, the knock limit will be reached more smoothly at steady state. . Of course, in any case, the advance angle speed during acceleration must be greater than during steady state.

(For example, set the advance angle during acceleration to 0.2°O'A/1 ignition, and set the advance angle at steady state to 1'OA/!30 ignitions).

Furthermore, although a microcomputer is used as the control circuit 8 in this embodiment, it may also be constructed from an analog circuit.

For example, it uses a capacitor and a constant current source, and uses the capacitor's charging and discharging characteristics to retard the advance angle. In this case, since the advance angle is performed continuously, the advance angle speed can be changed by changing its slope. In other words, the charging/discharging characteristics of the capacitor can be changed by switching between a plurality of constant current sources, and the slope of the advance angle can be changed.

As explained above, in the present invention, the acceleration state is determined based on whether the knock occurrence interval is shorter than a predetermined dawn (28), and the advance angle speed is increased, and the advance angle speed is increased. Since it determines whether a steady state has been reached based on sensor information and reduces the advance angle speed, it has the excellent effect of ensuring stable drivability in steady state while eliminating sluggishness during acceleration. .

Further, since no special acceleration detector is required, there is an added advantage of cost L, and there is an excellent effect that stable control can be performed without being affected by environmental conditions or changes over time.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing one embodiment of the present invention, FIG. 2 is a configuration diagram of the knock detection circuit in Figure @1, FIG. 8 is a signal waveform diagram for explaining the operation of the knock detection circuit, and FIG. The figure is a block diagram of the control circuit in Figure 1, Figures 5, 6, and 7 are flowcharts showing the arithmetic processing procedure in the control circuit, and Figure 8
The figure is a diagram showing a control state of ignition timing in the present invention. 1...Engine, 8...Air flow meter, 5A. 5B...Reference angle sensor and crank angle sensor, respectively. 6...knock sensor? ...knock detection circuit, 8.
Control circuit including: 10--Igniter and ignition coil, 80 o-CPU, s
o o t-ROM. 8002...Bonmu M0 Representative Patent Attorney Takashi Mabe

Claims (5)

[Claims] (1) A knock sensor that detects knocking of an internal combustion engine, an ignition timing control means that generates an ignition timing control signal that is advanced or retarded according to the output signal from the knock sensor, and an ignition timing control signal that is activated by the ignition timing control signal. In the ignition timing control device for an internal combustion engine, the ignition timing control means increases the advance angle speed when the knock occurrence interval is shorter than a predetermined value a plurality of times. Advance angular speed control means that reduces the advance angular speed when the subsequent ignition timing reaches a predetermined target ignition timing when the angular velocity is increased, or when knocking occurs a predetermined number of times before reaching the target ignition timing. An ignition timing control device for internal combustion engines that is patented as having: (2) The target ignition timing is an ignition timing retarded by a predetermined value β0 crank angle (β?0) from the most advanced ignition timing determined according to the engine speed and load. An ignition timing control device according to claim 1. (3) The target ignition timing is an ignition timing advanced by a predetermined crank angle (r>O) from the ignition timing at the time when the advance speed increases. The ignition timing control device described in . (4) The ignition timing control device according to claim 1, wherein the target ignition timing is an ignition timing calculated based on past ignition timings stored in memory. (5) The advance angle speed control means increases the advance angle speed at a time delayed by a predetermined number of cycles or a predetermined time from the time when the knock occurrence interval continues to be shorter than a predetermined value a plurality of times; According to any one of claims 1 to 4, when a knock occurs during a delay period, the advance angle speed is increased after another delay period after the end of the knock. Ignition timing control device.