JPS6187974A - Ignition timing controller for engine - Google Patents

Abstract

PURPOSE:To ensure the output under stack operation by setting the maximum lag angle low through maximum lag angle setting means upon decision of stack operation through detection of repeated stepping and release of accelerator pedal. CONSTITUTION:Under operation of engine, basic lead angle operating means a will operate the basic lead angle on the basis of the engine load and the engine rotation. While knock control means B will produce the lag angle of ignition timing against the basic lead angle which is increased upon occurrence of knocking while decreased under normal condition. Upon decision of stack operation through detection of repeated stepping and releasing of accelerator pedal by means of stack operation detecting means, maximum lag angle setting means D will set the maximum lag angle low. Lag angle determining means E will compare said lag angle with the maximum setting level to employ the lower one as the lagging angle.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ignition timing control device for an engine, and more particularly, to an ignition timing control device with added knock control.

[Conventional technology]

The ignition timing control device with knock control was developed in Japanese Patent Application Laid-open No. 1983.
-7978, and others. This sets the basic ignition timing, that is, the basic advance angle, to an optimal value that does not take into account the occurrence of knocking, and on the other hand, detects knocking that occurs in the engine, and when non-king is detected, the ignition The timing is retarded, and only when knocking is not detected, the timing is advanced toward the basic advance angle.

In this ignition timing control device, the ignition timing is not retarded unless knocking occurs, so the ignition timing is controlled to be basic advanced and the performance of the engine can be fully demonstrated. Furthermore, a limit is set on the retardation of the ignition timing in accordance with the detection of non-king, to prevent the ignition timing from being abnormally controlled to the retard side.

When a vehicle becomes stuck in snow, mud, etc. and becomes difficult to escape from, in other words, when the vehicle is stuck, it is common for the driver to try to escape by repeatedly pressing and releasing the accelerator pedal. be.

[Problem that the invention seeks to solve]

However, when an in-vehicle engine is equipped with a knock control function as described above, the knocking that occurs transiently when the accelerator pedal is depressed can cause the ignition timing to be retarded, causing the ignition timing to be delayed more than necessary. I was cornered,
Accordingly, there is a problem in that the engine output is suppressed.

On the other hand, it is conceivable to make the lk main river angle smaller in advance to prevent transient knocking from occurring when the accelerator pedal is depressed. The ignition timing is retarded from the desired position due to the smaller basic advance angle. It is also possible to set the maximum value of the retardation amount, which is the retardation limit, to a small value, but if this is done, the retardation amount will be insufficient in driving conditions where knocking is likely to occur, causing knocking that is harmful to the engine. Resulting in.

Therefore, an object of the present invention is to prevent the ignition timing from being retarded more than necessary when the engine is stuck, without reducing the maximum value of the basic advance angle or retard amount.

[Means for solving problems]

Therefore, the present invention is characterized in that when the vehicle is stuck, the maximum value of the retard amount is reduced only at that time.

Specifically, as shown in FIG. 1, in the ignition timing control device of the present invention, the basic advance angle calculation means calculates the basic advance angle based on the engine load and engine rotation speed, and the knock control means calculates the basic advance angle. The amount of retardation of the ignition timing with respect to the angle is determined, and this value increases when knocking is detected and decreases when knocking is not detected.

On the other hand, the stuck operation detection means detects repeated depression and release of the accelerator pedal to detect stalled operation, and the maximum retard amount setting means detects the maximum retard amount determined by the knock control means. , usually the first
When a set value is set and stuck operation is detected by the stuck operation detection means, a second set value smaller than the first set value is set.
Set the setting value.

Further, the retard amount determining means compares the retard amount determined by the knock control means with the maximum value set in the maximum retard amount setting means, and if the former is smaller than the latter, the former is used as is. If the former is larger than the latter, the latter is used as the retard amount. Then, the ignition timing calculating means adds the retard amount obtained from the retard amount determining means to the basic advance angle calculated by the basic advance angle calculating means to determine the final ignition timing.

[Effect]

When stuck operation is not detected by the stuck operation detecting means, the maximum value of the retard amount is set to the normal first setting value in the maximum retard amount setting means, and the retard amount is increased in the knock control means in accordance with the occurrence of knocking. Even if it is done,
The first setting value is not easily exceeded, and the ignition timing is retarded as necessary. Furthermore, if almost no non-king occurs, the retard amount is reduced in the knock control means, so the ignition timing calculated by the ignition timing calculation means is set to a value close to the basic advance angle calculated by the basic advance angle calculation means. Ru.

On the other hand, when stuck operation is detected by the stuck operation detection means, the maximum value of the retard amount set by the maximum retard amount setting means is set to a smaller second setting value, so that transient Even if the knock repeatedly occurs and the retard amount increases in the knock control means, the retard amount is set smaller than the second set value in the retard amount determining means, and the ignition timing is retarded more than necessary. can be prevented.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a system configuration diagram of an embodiment of the present invention,
Here, 10 is a 4-cycle 6-cylinder engine body, 30
is a knock sensor attached to the cylinder block of the engine body 10. The knock sensor 30 is a well-known device that is composed of, for example, a piezoelectric element or an electromagnetic element, and converts mechanical vibration into electrical vibration fluctuation. In FIG. 2, 21 further indicates a distributor, and this distributor 21 is provided with crank angle sensors 24 and 25. The crank angle sensor 24 is for cylinder discrimination, and if this engine has 6 cylinders, every time the distributor shaft makes one revolution, that is, every two revolutions of the crankshaft (every 720° CA).
generates one pulse. The occurrence position is set, for example, to a position slightly before the top dead center of the first cylinder. The crank angle sensor 25 generates 24 pulses for each rotation of the distributor shaft, ie, pulses at a crank angle of 3°.

Electric signals from knock sensor 30 and crank angle sensors 24 and 25 are sent to control circuit 4o. The control circuit 40 is further supplied with a signal representing the amount of intake air from an air flow sensor 5I provided in an intake passage 52 of the engine, and a signal representing the amount of intake air is sent to the control circuit 40 from a throttle sensor 55 provided in a throttle valve 56 in the intake passage 52. A signal representing the fully open position of valve 56 is sent.

On the other hand, the control circuit 40 outputs an ignition signal to the igniter 22, and the spark current generated by the igniter 22 and the ignition coil 23 is transmitted to the distributor 2.
1 to each spark plug 54.

The engine is usually provided with various other sensors that detect operating state parameters, and the control circuit 40 also controls the fuel injection valves 53, etc., but these are not directly related to the present invention. , all of these will be omitted in the following description.

FIG. 3 is a block diagram showing an example of the configuration of the control circuit 40 in FIG. 2. The voltage signal from the air flow sensor 51 is sent to an analog multiplexer 43 via a buffer 42a.
a, selected according to instructions from the microcomputer, and sent to the A/D converter 43b.
1k converted into a forward signal and taken into the microcomputer via the summer 10 boat 41d.

The signal from the throttle sensor 55 is sent to a buffer 42b,
The pulses sent to the microcomputer via the I10 boat 41e, and the pulses every 720 degrees of crank angle from the crank angle sensor 24 and the pulses every 30'' of crank angle from the crank angle sensor 25 are sent to the microcomputer 42, respectively.
c and 42d, and is sent to the microcomputer via the I10 port 41G.

The output signal of the knock sensor 30 is transmitted through a buffer for impedance conversion and a frequency band (7 to 7) specific to knocking.
8 KHz) is sent to a peak hold circuit 44b and a rectifier circuit 44c via a circuit 44a consisting of a bandpass filter having a pass band. Peak hold circuit 4
4b takes in the output signal from the knock sensor 30 and holds the maximum amplitude only when a logic level "1" signal is applied from the microcomputer via the line 44-g and the 10 port 41e. conduct. The output of the peak hold circuit 44b is sent to an analog multiplexer 44e, selected according to instructions from the microcomputer, sent to an A/D converter 44f, converted into a binary signal, and then sent via a 110 port 41e. and is incorporated into the microcomputer. Rectifier circuit 44
c. The output signal from the knock sensor 30 is subjected to full-wave rectification or anti-wave rectification. The rectified signal is sent to an integrating circuit 44.
d and integrated with respect to time.

Therefore, the output of the integrating circuit 44d is a value obtained by averaging the amplitudes of the output signals of the knock sensor 30. Integrating circuit 44d
The output is sent to an analog multiplexer 44e, selectively sent to an A/D converter 44f, converted into a binary signal, and then taken into the microcomputer. However, the A/D converter 44f (DA/D conversion start is performed by a Δ/D conversion start signal applied from the microcomputer via the I10 port 41e and line 44h. Then, A/
L) Transducer 44f connects line 44i and I10 boat 4I
Notification of completion of Δ/D conversion is sent to the microcomputer via C.

On the other hand, when an ignition signal is output from the microcomputer to the drive circuit 45 via the I10 port 41e, this is converted into a drive signal, energizes the igniter 22, and ignites according to the duration and duration of the ignition signal. Control takes place.

The microcomputer includes the aforementioned I10 ports 41d and 41e, a microprocessor (MPU) 41a,
Random access memory (RAM) 41b, read only memory (ROM) 41c.

It mainly consists of a clock generation circuit (not shown), a memory control circuit, a bus 41f connecting these circuits, etc., and executes various processes according to a control program stored in the ROM 41C.

Next, the operation of the microcomputer will be explained using a flowchart.

FIG. 4 shows part of the initial processing routine and the main processing routine. When the engine ignition switch (not shown) is turned on, the MPU 41 a
First, the initial processing of steps 101 and 102 is executed, and thereafter, the main processing, a part of which is shown in steps 103 to 107, is repeatedly executed.

In step 101, the I10 boats 41d and 41e
is set to the initial state, and in step 102, RAM4
Clear lb and set initial data. In the next step 103, the clock of the input/output counter is defined by, for example, setting the timing cycle of A/D conversion. In the next step 104, an address th is determined to which the contents of the program counter and registers are to be saved when an interrupt occurs. In step 105, interrupt acceptance processing is performed. In the next step 106, the air flow sensor 51 is sent through the A/D converter 43b,
Calculated using the intake air amount data Q stored in RAM4 Ib and the interrupt processing routine shown in FIG.
The engine rotational speed data Ne stored in AM4 lb is taken in and Q/Ne is calculated. Next, in step 107, a basic advance angle θb is determined from Q/Ne and Ne using a basic advance angle map. A basic advance angle map for Q/Ne and Ne is stored in advance in the ROM 41C, and in step 107, θb is determined using complementary calculation or the like. When the processing in step 107 is completed, other processing for the main processing routine is executed, and then the same processing is repeated again from step 103.

FIG. 5 shows an interrupt handling routine that is executed every 30'' crank angle. This interrupt handling routine is executed every time a pulse of 30° crank angle is sent from the crank angle sensor 25. Calculation of rotational speed Ne, TDC160”CA-BTDC, 90°CA
- Detects each position of BTDC and performs calculation processing required at each position.

When an interrupt occurs, first, in step 201, the engine rotational speed Ne is calculated. As is well known, this is calculated from the difference between the values of the free run counter at the time of the previous interrupt and the time of the interrupt.

In the next step 202, it is determined whether or not the flag FG, which is set to "1" at the reference position every 720° CA in step 3°1 of FIG. 6, has been set.

If step 202 is negative, that is, the flag FG
If FG=0, the program proceeds to step 203 and increments the 30° CA interrupt count ω by "1". That is, the process ω←ω+1 is performed.

On the other hand, if the determination in step 202 is affirmative, that is, the FC
If =1, the flag FG is reset to FG=0 in step 204, and the 30'' CA interrupt count ω is cleared to rOJ in the next step 2°5.

In this way, in steps 202 to 205, the number of 30'' CA interruptions ω starting from the reference position every 720' CA from the crank angle sensor 24 is calculated.

In step 206, the number of 30'' CA interruptions ω is divided by a constant “4”, and the decimal part of the divided value ω/4 is set as the indicated value n of the crank angle position. Here, if the indicated value n is n=Q, one generosity is TDC, n=0.2
5(7), 9o″CA-BTDC, n=0.5(
7) means that the crank angle position is 60" CA-BTDC.

In step 207, it is determined whether the above-mentioned instruction value n is rOJ. If n=Q, i.e. the current 30″CA
If the interrupt matches the TDC of the compression stroke of one cylinder, the process proceeds to step 208, where a process is performed to confirm that the knock gate is closed. This is controlled only by switching the knock gate on and off alternately in the A/D conversion completion interrupt processing routine shown in FIG. 9, and the knock gate on period and off period are opposite to each other. This is normalized because there is a risk that it may become . Note that the knock gate is gate means that is opened to detect a knocking signal from the output of the knock sensor 3o, and in this embodiment, the hold operation period of the peak hold circuit 44b is the knock gate ON period and other periods. is the knock gate-off period.

In the next step 209, an instruction is given to start A/D conversion of the channel of the integrating circuit 44d. With this, A/D
The converter 44f converts the pack ground component A of the output of the integrating circuit 44d, and hence the output of the knock sensor 3o.
/Start D conversion.

Next, in step 210, the closing time t of the knock gate is calculated, and a value corresponding to this time t is set in the conveyor register A for starting a time coincidence interrupt. Note that the MPU 41a is provided with this conveyor register A and a conveyor register B described later, each of which is used for activating a time coincidence interrupt.

If a negative determination is made in step 207, or after executing step 210, the MPU 41a performs step 2.
11 is executed. In step 211, the indicated value n
Determine whether or not is rO,25J. n=0.25
In this case, that is, if the current 30'' CA interrupt corresponds to 90'' CA-BTDC of one cylinder, the program proceeds to step 212 and determines the maximum value of the retard amount, which will be described later in FIG. The maximum retard amount calculation process is executed, and then the process proceeds to step 213, where the ignition timing calculation process, which will be described later with reference to FIG. 13, is executed.

After the step knob 211 makes a negative determination or after executing step 213, the program proceeds to step 214 and determines whether the indicated value n is r 0.5 J. If n = 0.5, that is, if the current 30'CA interrupt corresponds to 60° CA-BTDC of one cylinder, the process proceeds to step 215.

In step 215, the off time of the igniter 22, that is, the time when ignition is performed, is calculated from the ignition advance angle θ calculated in step 912 of FIG. set.

If a negative determination is made in step 214 or after execution of step 215, the program returns to the main processing routine of FIG. 4.

The time set in the conveyor register A, that is, the knock gate closing time calculated in step 210 of FIG.
When the time A arrives, the MPU 41a executes the coincidence interrupt processing at time A shown in FIG. That is, Ste Knob 401
In, the output of the peak hold circuit 44b, therefore,
A/D conversion of the knocking component a of the output of the knock sensor 30 is started.

Upon receiving notification of the completion of A/D conversion from the A/D converter 44f, the MPU 41a executes the interrupt process shown in FIG. 9. First, in step 601, it is determined whether the knock gate is currently on.

If step 601 is negative, that is, if the peak hold operation is not in progress, proceed to step 602,
Let us assume that the A/D conversion value at that time is the bank ground value.

Next, in step 603, the knock gate is opened. Opening the knock gate means 110 boats 41
This means that the signal applied to the peak hold circuit 44b via the line 44g and the line 44g is inverted to "1", and as described above, the peak hold operation is performed during the signal period of the "1" level.

On the other hand, if the determination in step 601 is affirmative, that is, if the peak hold operation is in progress, in step 604,
Let the A/D conversion value at that time be the knocking value a. Next, in step 605, the signal applied to the peak hold circuit 44b described above is inverted to "0" to close the knock gate.

When the time set in conveyor register B arrives, M
The PU 41a executes the coincidence interrupt process at time B shown in FIG. First, in step 501, it is determined whether the interrupt is related to the igniter on time. If step 501 is negative, that is, if the interrupt is related to the igniter 22 off time calculated in step 215 of FIG. 5, the process proceeds to step 502, where the ignition signal is reversed from on to off. As mentioned earlier, this ignition signal is sent to the drive circuit 45 via the I10 port 41e, and when it is reversed from on to off, the energization to the ignition coil (not shown) stops at that point, and the spark plug The ignition spark is generated from the

On the other hand, if an affirmative determination is made in step 501, that is, if the interrupt is related to the on time of the igniter 22 calculated in step 913 of the processing routine of FIG. be reversed.

FIG. 15 shows a time chart of operations related to the processing routines of FIGS. 5 to 9 described above. FIG. 6A shows a 72OCA pulse from the crank angle sensor 24, which causes the interrupt processing shown in FIG. 6 to be executed. (B)
is a 30° CA pulse from the crank angle sensor 25, which causes the interrupt processing shown in FIG. 5 to be executed.

(C) shows the instruction value n of the crank angle position calculated from ω/4 in the 30° CA interrupt processing routine. As mentioned above, depending on this instruction value n, each cylinder's TDC190°CA - BTDC160" CA
- It is possible to determine the crank angle position of F3TDC and execute the processing that should be performed at each position.
? -4(1)) is the on/off period of the knock gate,
That is, it shows a period in which the peak hold operation is performed and a period in which it is not performed. Further, (1':) in the same figure shows an ignition signal.

FIG. 10 shows in detail step 212 in the interrupt processing routine of FIG. 5, which is a routine for calculating the maximum retard angle p. This routine is executed at 90° CA-BTDC for each cylinder, as described above.

When this routine is executed, first, in step 921, it is determined whether the flag FDL is set, and in step 922, it is determined whether the signal rDL from the throttle sensor 55 is rOJ. is determined. XIDL is "1" when the throttle valve 56 is in the fully closed position, and is "0" in other positions.

Further, in step 924, it is determined whether or not XIDL is "1", and when X I DL=1, the flag FIDL is set to "1" in step 925.

Therefore, when the accelerator pedal (not shown) is depressed,
When the throttle valve 56 reaches a predetermined opening degree from the fully closed position, the flags FIDL=1 and XIDL=O are set.
Therefore, both steps 921 and 922 are answered in the affirmative, and the process proceeds to step 923, where the flag FIDL is
is reset to "0". Thereafter, when the accelerator pedal is released again and the throttle valve 56 is brought to the fully closed position, the flag FTDL=0, X
Since IDL=1, the step knob 921 is determined to be negative, step 924 is determined to be affirmative, and step 925 is determined.
The flag FIDL is set in rlJ. If the accelerator pedal is not depressed or released and the previous operation continues, the flag FIDL and >
Since IDL is "l", "1" or "0", "0", step 921 is determined to be affirmative and step 922 is determined to be negative, or step 921 is determined to be negative and step 924 is also determined to be negative. Therefore, the flag FIDL is not changed. The process then proceeds to step 936, which will be described later.

When the accelerator pedal is depressed, steps 921 and 922 are both answered in the affirmative as described above, and step 923 is executed.
When the process proceeds to step 931, it is determined whether one timer counter CT1 is greater than "0", that is, whether or not the timer counter CT is activated. The timer counter CT is configured by an interrupt processing routine every 50 milliseconds as shown in FIG.
The process of step 701 is performed every I seconds, and the count value of the timer counter CT is incremented.

When timer counter CT is not started, C
Since T,=O, step 931 is determined to be negative,
In step 932, a timer counter CT is activated. Therefore, the activation of the timer counter CT is the 11th
This is done by enabling interrupts for the processing routine shown in the figure, and interrupts are disabled until the processing routine is activated.

When timer counter CT is activated, CT
, >Q, an affirmative determination is made in step 931, and step 932 is skipped.

Then, in step 933, the counter CIDL is incremented.

Next, in step 934, the value of the counter cfDL is "
5'' or more is determined. While the value of the counter CIDL has not yet reached "5" or more, a negative determination is made in step 934, and in step 936 it is determined whether the count value of the timer counter CT has reached "200" or more, that is, the timer counter CT It is determined whether 10 seconds have passed after the activation of . If the count value of the timer counter CT is r200J or more, an affirmative determination is made in step 936, and in steps 937 and 938, the counter CID
Both L and timer counter cT1 are cleared. When the timer counter CT is cleared, interrupts of the processing routine of the 11th FI are prohibited. However, when the count value of timer counter CT does not reach r200J or more, a negative determination is made in step 936, and step 937.
The process at 938 is skipped.

On the other hand, when the value of the counter CIDL becomes "5" or more, an affirmative determination is made in step 934, and in step 935, another timer counter CT2 is activated. When the timer counter cT2 is started, the interrupt of the processing routine of FIG.
” is executed every v seconds, and the timer counter CT2 is incremented. Then, the processing of steps 937 and 938 is executed, and the counter CIDL and the timer counter C
T is cleared.

Therefore, in steps 921 to 938, when the accelerator pedal is depressed and released five times or more within 10 seconds according to the timer counter CT2, the timer counter CT2 is activated. In other words, this time is determined to be the time of stack operation.

Next, in steps 939 and 940, the timer counter C
The count value of T i is greater than "0" or r100J
It is determined whether the count value of the timer counter CT2 is "0", between "1" and r99J', or whether it is greater than or equal to I"100J.Timer counter c
'20 seconds have passed since r2 started, and the count value is rlo
When it is equal to or greater than OJ, both steps 939 and 940 are affirmatively determined, and the process proceeds to steps 942 and 943, where the timer counter CT is cleared, interrupts of the processing routine of FIG. 12 are prohibited, and the maximum retard amount is θma
x is set by map I. Further, if the timer counter CT2 has not been activated (and its count value is "0"), a negative determination is made in step 939 and the process directly proceeds to step 943, in which the timer counter CT2 is changed from rlJ to "9".
9”, an affirmative decision is made in step 939;
If a negative determination is made in step 940, the process proceeds to step 941, where the maximum retard amount θmax is set by the control knob ■.

The maps ■ and ■ for setting the maximum retardation amount θmax are as follows:
As shown in Fig. 17, it is predetermined for the engine rotation speed, where MAP I gives the maximum retard amount that is normally set, and MA knob ■ gives the maximum retard amount that is normally set, and MA knob This gives the maximum retard amount to be set, and the maximum retard amount of map (2) is set smaller than that of map (I).

FIG. 14 shows a time chart of operations related to the processing routine shown in FIG. 1O above. (A) shows XIDL, which is the signal of the throttle sensor 55, and when the throttle valve 56 is in the fully closed position, XIDL is "l".
”, the accelerator pedal is depressed, and the
6 is opened, XTDL becomes "0". (B) shows the change in flag FIDL, and as mentioned above, flag FIDL
DL stores the state of XIDL, and
At a timing slightly later than L, it becomes the same state as XIDL. (C) is the count value of counter CIDL, (
D) is a timer counter CT.

, and both indicate the count value of flag FIDL.
is "1" and XIDL is switched from rlJ to "0", that is, when the accelerator pedal is depressed, counting starts, and the counter CIDL is incremented each time the accelerator pedal is depressed, and the timer counter CT, is incremented every 50 milliseconds until the counted value reaches r200j, that is, until 10 seconds have elapsed after startup. However, when the count value of the counter CIDL reaches "5" or the count value of the timer counter CT reaches r200J, the counter CIDL and the timer counter CT are cleared. Before the count value of timer counter CT reaches "200", counter C
When the IDL count value reaches "5", that is, when the accelerator pedal is released and depressed five times within 10 seconds after the accelerator pedal is depressed for the first time, it is determined that the vehicle is in stuck operation.

(E) shows the count value of the timer counter CT, and the timer counter CT2 starts counting when the stack operation is detected, and the count value is incremented every 2001 seconds and is cleared when it reaches rloOJ. be done. (F
) indicates whether the maximum retard amount is set by map I or H, and the timer color/CT starts counting.
During the 20 seconds during which it is activated, it is designated as map ■, and at other times, it is designated as map I.

FIG. 13 shows step 213 in the interrupt processing routine of FIG. 5 in detail, and is a routine for calculating ignition timing. As mentioned earlier, this routine is executed at 90° CA/B TDC for each cylinder. First, the contents of this processing routine will be briefly explained.

It is detected from the knocking value a and the hack ground value whether or not knocking has occurred, and the retard amount θk is adjusted accordingly.
is controlled to increase or decrease. This retard amount θk is compared with the maximum retard amount θmax determined as described above, and if the retard amount θk is smaller than the maximum retard amount θmax, the retard amount θ is left unchanged; When the amount θk is larger than the maximum retard amount θmax, the maximum retard amount θmax is set to the retard amount θ. The final ignition advance angle θ is calculated using the retard amount θk thus determined.

Hereinafter, the above-mentioned processing contents will be explained in detail according to the flowchart of FIG. 13.

First, in step 901, it is determined whether the knocking value a obtained in the A/D conversion completion interrupt processing routine of FIG. judge.

If step 901 is affirmatively determined, that is, a≧−
If b, it is determined that knocking has occurred and the process proceeds to step 902, and if the determination is negative, it is determined that no knocking has occurred and the process proceeds to step 904.

In step 902, the retard amount θk is increased by "1° CA", and processing is performed so that the ignition timing is finally delayed by l"CA. In the next step 903, the number of consecutive times when knocking is not detected is determined. The number of non-detection times m representing knocking
is reset to "0" and the program then proceeds to step 908.

On the other hand, if it is determined that no knocking has occurred and the process proceeds to step 904, it is determined whether or not the number of non-detected knocks m is less than or equal to "10". If m≦10, the process proceeds to step 905 and m is incremented by 1. Ru. Also, m is “
If the retardation amount θk exceeds "1° CA
The ignition timing is decreased by J, and the ignition timing is finally advanced by 1° CA. Next, in step 907, m is cleared to "0", and then the process advances to step 908.

In step 908, the retardation amount θ obtained as described above and the maximum retardation amount θma obtained in the processing routine of FIG.
x and determines whether the retard amount θk is greater than or equal to the maximum retard amount θmax. If the retardation amount θk is smaller than the maximum retardation amount θmax and the steering knob 908 is determined to be negative,
The process proceeds to step 910, and if the retard amount θk is greater than or equal to the maximum retard amount θmax, an affirmative determination is made in step 908, and in step 909, the retard amount θk is set to the maximum retard amount θ.
Replaced by max. In other words, the maximum value of the retard amount θ is limited by the maximum retard amount θmax.

Further, in step 910, it is determined whether the retard amount θk is smaller than "0". If the retard amount θk is "0" or more, a negative determination is made in step 910, and the process proceeds to step 912 without performing any processing, but if the retard amount θk is "0".
If it is smaller, that is, if the retard amount θk is negative, in step 911, the retard angle 9θk is set to 10.
In other words, the retard amount θ is not set to be smaller than "0".

In the next step 912, the final ignition advance angle θ is calculated from the basic advance angle θb calculated in step 107 of the main processing routine in FIG. 4 and the retard amount θ obtained as described above.
Calculated by -θb-θk.

In step 913, the ignition advance angle θ obtained as described above is
The time when the igniter 22 is turned on, in other words, the time when the ignition signal is turned on, is calculated a predetermined time after the time corresponding to , and the calculated value is set in the conveyor register B for starting the time coincidence interrupt. .

FIG. 16 shows the change in the retard amount θ during stack operation, where (8) shows the change in X11)L. During stack operation, if >ID-L does not repeatedly become "1" and "0", XIDL
Every time lJ changes to "0", that is, every time the accelerator pedal is depressed, a transient knock occurs in the engine, and the retard amount θk is increased. In this way, if the retard amount θk is made too large, the ignition advance angle θ becomes small and the engine output is suppressed. However, in the present invention, as described above, XrDL(7)rlJ, rOJ When repeated switching is detected and it is determined that the stack operation is in progress, the delay is changed as shown in (B) in order to reduce the maximum retard amount θ1lIax from map I to ■. The angle amount θ is reduced at the time when stuck operation is detected, and this prevents the ignition advance angle θ from being made smaller than necessary.

In the flowcharts of FIGS. 4 to 13, the processing in steps 106 and 107 corresponds to the basic advance angle calculation means of the present invention, and the processing in steps 208 to 210, 401, and 60 corresponds to the basic advance angle calculation means of the present invention.
The processes of steps 1 to 605.901 to 907 correspond to the knock control means of the present invention, the processes of steps 701.921 to 938 correspond to the stack operation detection means of the present invention, and the processes of steps 801.939 to 943 corresponds to the maximum retard amount setting means of the present invention, the processing of steps 908 and 909 corresponds to the retard amount determining means of the present invention, and step 912
The processing corresponds to the ignition timing calculation means of the present invention.

Although specific embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and includes various embodiments within the scope of the claims. For example, the stuck driving detection means may measure the period from when the accelerator pedal is depressed until it is released and then when the accelerator pedal is depressed again, and detect stuck driving if the period is shorter than a predetermined period. .

〔Effect of the invention〕

According to the present invention, the stuck operation detection means detects whether or not the stuck operation is present, and only when the stuck operation is detected, the maximum retard amount setting means sets the maximum value of the retard amount to a small value. Therefore, in operating conditions where knocking is likely to occur, the retard angle 9 is sufficiently retarded without being insufficient, and even if transient knock occurs during stack operation, when you do not want the retard angle to be too much, the retard angle 9 can be set more than necessary. You can prevent it from being delayed.

Therefore, engine output during stack operation can be ensured.

[Brief explanation of drawings]

Fig. 1 is a complaint correspondence diagram, Fig. 2 is a system configuration diagram of an embodiment of the present invention, Fig. 3 is a block diagram of the control circuit of Fig. 2, and Figs. FIG. 3 is a flowchart showing the program contents of the microcomputer, FIGS. 14 to 16 are time charts explaining the operation of one embodiment, and FIG. 17 is a diagram showing the maximum retard amount. 10---Engine body 2I---Distributor 22---Igniter 23---One ignition coil 30---Knock sensor 40---One control circuit 51------M- Air flow sensor 55 ------- Throttle sensor Applicant: Toyota Motor Corporation Figure 1 Figure 6 Figure 8 Figure 7 Figure 9 Figure 1Q Figure 13 Figure 15 District 16 Figure 17

Claims (1)

[Scope of Claims] 1. A basic advance angle calculation means for calculating a basic advance angle based on the engine load and engine rotational speed; a knock control means that increases the amount of retardation and decreases when knocking is not detected; a stuck operation detection means that detects stuck operation by detecting repeated depression and release of the accelerator pedal; maximum retard amount setting means for normally setting a first set value as the maximum value, and setting a second set value smaller than the first set value when stuck operation is detected by the stuck operation detection means; The amount of retardation found in the control means is compared with the maximum value set in the maximum retardation amount setting means, and if the former is smaller than the latter, the former is used as the retardation amount, and if the former is larger than the latter, the latter is set. A retard amount determining means that uses the retard amount as it is, and an ignition timing calculation that calculates the final ignition timing by adding the retard amount obtained from the retard amount determining means to the basic advance angle determined by the basic advance angle calculating means. An ignition timing control device for an engine, comprising: means.