JPS59162365A - Method of controlling ignition timing of engine - Google Patents

Abstract

PURPOSE:To generate hither power of an engine by setting the ignition timing to a specified value according to the revolution speed of the engine and the amount of intake air at the rapid acceleration time in the method of controlling ignition timing wherein the timing is delayed at acceleration time and thereafter gradually advances. CONSTITUTION:A foundamental ignition timing map is stored in ROM 38 of a control circuit 34 in advance, which controls an ignitor 28 by adding a compensating ignition timing to the map. If the rapid acceleration state is detected, the controller resets a timer. Said timer interrupts normal control 8 having the ignition timing advance, for a certain duration after the time of detecting the accelerated state, and sets the ignition timing to a specified value according to engine speed and amount of intake air. Since once rapid acceleration is detected, the ignition timing is set to the specified value for a certain duration 1st from the point of detecting the acceleration, the engine output may be improved and fuel consumption be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an ignition timing control method that detects intake air amount and engine rotational speed and controls ignition timing based on these data.

[Prior art]

Airflow metering is used to measure the amount of intake air in an engine, but during sudden acceleration, the amount of intake air increases, causing the actual engine to temporarily enter the engine immediately after the throttle valve is suddenly opened. A phenomenon occurs in which the air flow meter outputs an intake air amount signal as if there is an amount of intake air that is greater than the intake air amount.

The ignition timing is controlled by MBT (Minimum 5p).
arkAdyance for Be5t Torqu
In order to comply with (e), the ignition timing on the high load side is delayed, and the ignition timing is adjusted to stabilize the ignition timing and ensure normal ignition even if the ignition timing calculation is incorrect. When advancing the angle, I try to advance it steadily. For this reason, as described above, even when the engine is rapidly accelerating, the ignition timing continues to be delayed, resulting in a decrease in engine output and deterioration in fuel efficiency.

[Purpose of the invention]

An object of the present invention is to provide an engine ignition timing control method that suppresses excessive retardation of ignition timing when sudden acceleration is detected, and improves engine output and fuel efficiency.

[Concept of the invention]

The present invention retards the ignition timing during acceleration and then gradually advances the ignition timing, and is characterized in that the ignition timing is set to a predetermined value immediately after a sudden acceleration state is detected.

[Embodiments of the invention]

The overall configuration of an engine control device to which the present invention is applied is described first.
As shown in the figure.

As shown in the figure, the engine main body 14 includes an air flow meter 2 as an intake air amount sensor provided downstream of an air cleaner (not shown).

Air flow meter 2 is placed inside the damping chamber (M)
Two conven motion plates and
It consists of a compensation motion plate and a potentiometer 2B that detects the opening degree of two people.

Therefore, the intake air amount Q is detected as the voltage output from the potentiometer 2B.

Further, an intake air temperature sensor 4 is provided near the air flow meter 2 to detect the temperature of intake air.

A throttle valve 6 is arranged downstream of the air flow meter 2, and a surge tank 8 is arranged downstream of the throttle valve 6.

This surge tank 8 has an intake manifold 10
are connected to each other, and a fuel injection valve 12 is disposed protruding into this intake manifold 10.

The intake manifold 10 is connected to a combustion chamber 14A of the engine body 14, and the combustion chamber 14A of the engine is connected via an exhaust manifold 16 to a catalytic converter (not shown) filled with a three-way catalyst.

The engine body is provided with a knock sensor 18 that detects engine vibrations and is composed of a microphone or the like.

Note that 20 is a spark plug, 22 is an 02 sensor for controlling the air-fuel mixture near the stoichiometric air-fuel ratio, and 24 is a cold/hot water temperature sensor for detecting the engine cooling water temperature.

The engine main body 1, 40 spark plug 20 is connected to a distributor 26, and the distributor 26 is connected to an igniter 28.

The distributor 26 is provided with an oil/oil discrimination sensor 30 and an engine rotation angle sensor 32, each of which includes a pickup and a signal rotor fixed to the distributor shaft.

This cylinder discrimination sensor 30 outputs an oil/fuel discrimination signal to a control circuit 34 made up of a microcomputer or the like every 720 degrees of crank angle, for example.
2 outputs a crank angle reference position signal to the control circuit 34, for example, every 30 degrees of crank angle.

Reference numeral 80 denotes a throttle sensor for detecting the opening speed of the throttle valve 6, or in other words, a sudden acceleration state, and specifically has a configuration as shown in FIG.

That is, the throttle sensor 80 is printed and wired on a printed circuit board (not shown) or the like and has a resistor FLY.

A comb-shaped conductor portion 19c, 19d to which a constant voltage is applied via R2, and a sliding portion that is interlocked with the throttle valve 6 and slides on the conductor portions 19c, 19d when the throttle valve 6 is opened or closed. It consists of a section 82. The sliding portion 82 is provided coaxially with the throttle valve 6 and is made of an insulator.
It consists of a bar 84, a coil spring 19b1 extending from the base end of the lever 84, and a conductor piece 19a fixed to the tip of the lever 84 opposite to the coil spring 19b and grounded. .

As the throttle valve 6 opens, the coil spring 19b slides on the conductor portion 19C219d while being pushed by the conductor piece 19a, so that the terminal 19e is closed.

19f are alternately grounded, so that these terminals 19el
Nogle-shaped signals are alternately output from 19f.

These signals are used as interrupt signals in the acceleration detection interrupt routine described later.

As shown in FIG. 2, the control circuit 34 includes a random access memory (R, AM) 36, a read only memory (ROM) 38, a central processing unit (CPU) 40, and a clock (CLOCI<). 41, a first input/output port 42, a second input/output port 44, and a first output port
j46 and a second output port 48. R, A, M36° ROM38. CPU40. CLOC
K, first input/output port 42, second input/output port 44
, the first output port 46 and the second output port 48 are connected by a bus 50.

The first input/output port 42 is connected to a buffer (not shown) multiplexer 54, an analog-to-digital (A/D) converter 56, and an air flow meter 2 and a cooling water temperature sensor 2.
4, an intake air temperature sensor 4, etc. are connected thereto.

The multiplexer 54 and A/D converter 56 are controlled by a signal output from the first input/output port 42.

The second input/output port 44 includes a buffer (not shown).
The 02 sensor 22 is connected via a comparator 62, and the cylinder discrimination sensor 30 and the engine rotation angle sensor 32 are connected via a waveform shaping circuit 64.

The second input/output port 44 also has a pantone filter 0 and a peak hold circuit 61. Knocking sensor 18 is connected via channel switching circuit 66 and A/D converter 68.

This bandpass filter is connected to a channel switching circuit 66 via an integrating circuit 63.

This channel switching circuit 66 is connected to either the output of the peak hold circuit 61 or the output of the integration circuit 63.
A second input/output port 4 for inputting to the /D converter 68
A control signal output from the peak hold circuit 61 is inputted thereto, and a reset signal is inputted from the second input/output port 44 to the peak hold circuit 61 .

Further, when the throttle valve 6 is opened, the throttle sensor 80 outputs interrupt signals L9e and 19f to the waveform shaping circuit 82, and these signals are shaped by the waveform shaping circuit 82 and input to the input/output port 44.

Further, the first output port 46 is connected to the igniter 28 via a drive circuit 70, and the second output port 48 is connected to the fuel injection valve 12 via a drive circuit 72.

The ROM 38 of the control circuit 34 stores in advance a map of the basic ignition advance angle θBASE expressed by the engine speed and intake air amount, the basic fuel injection amount, etc. 3
The basic ignition advance angle and the basic fuel injection amount are read out based on the signals from 2, and the basic ignition advance angle and basic fuel injection amount are read out based on various signals including the signals from the cooling deficient temperature sensor 24 and the intake temperature sensor 4. A corrected ignition advance angle and a corrected fuel injection amount are added to the injection amount, and the igniter 28 and the fuel injection valve 12 are controlled.

The air-fuel ratio signal output from the 02 sensor 22 is used for air-fuel ratio control to control the air-fuel ratio of the air-fuel mixture to near the stoichiometric air-fuel ratio.

Next, a detailed explanation will be given of a case where the present invention is applied to the engine as described above. FIG. 4 shows the control circuit 34.
The interrupt routine that is executed by and activated every 30° CA is shown.

In the figure, when interrupt routing is started at step 100, the engine rotation speed N is determined based on the signal from the engine rotation angle sensor 32 at step 100, and at the next step 104, a cylinder discrimination signal is input from the cylinder discrimination sensor 30. After that, count the number of interrupts and set a flag indicating the current crank angle. Further, in step 106, it is determined whether the current crank angle is 90 degrees before top dead center (90 degrees BTDC), and if it is determined as "Yes" in step 106, the basic ignition advance angle θBAS is determined in step 108.
Find the ignition timing θIG from E.

Then, in the next step 110, the igniter ON time is determined from the ignition timing θIG and the current time, a time coincidence interrupt is set, and a flag F is set to turn the igniter ON.
IGON is set and the process moves to step 112.

On the other hand, if the determination in step 106 is NO, the process jumps to step 112.

Step] In step 12, the current crank angle is 600 before L dead center.
(60°B 'I-D C), and if it is determined as ``Yes'' in step 112, the next step 1]4 determines the ignition timing θIG and the igniter OJ from the current time. ” Find the time to F, set the time coincidence interrupt, clear the flag FIGON, and proceed to step 1.
At 16, the program returns to the main routine.

On the other hand, if it is determined in step 112 that //NO/l, the process jumps to step 116 and similarly returns to the main routine.

Next, FIG. 5 shows a time coincidence interrupt routine.

This interrupt routine is activated at the time set in steps 110 and 114 of the interrupt routine that is activated every 30° CA shown in FIG. In the figure, when the interrupt routine is started in step 120, it is determined in the next step 22 whether or not the plug "' IC0N is set, and if it is determined in step 122 that //Y eS// Step 12
At step 4, the igniter is turned on, and at set 128, the process returns to the interrupt mode.

On the other hand, if the determination in step 122 is NO, the process moves to step 126, where the igniter is turned off, and in step 28, the process returns to the interrupt mode.

Next, FIG. 6 shows the contents of the interrupt routine that is activated every 4m5ec. In the same figure, when the interrupt routine is started at step 130, it is determined whether it is step 132, and if it is determined at step 134 that //Y63//, the process moves to step 138.

On the other hand, if it is determined in step 134 that l/N is On, the timer TAC is set to 30 in step 136 and the process moves to step 138. Here, the timer TAC is a timer for determining a sudden acceleration state, in other words, for detecting the opening speed of the throttle valve 6. Now, in step 138, timer T,
The contents of AC1 are incremented by 1, and in the next step 140 it is determined whether or not the contents of the timer (TAC1 is TAC1≦130).

If it is determined in step 140 that the content of timer TACI exceeds 130, the process returns to interrupt mode in step 144. On the other hand, if it is determined in step 140 // Not/, that is, if it is determined that the content of timer TAC1 exceeds 130, the content of timer TAC1 is set to ]30 in step ]42, and the interrupt is set in step 144. Return.

Note that the timer TACI is a timer for stopping the normal control operation of advancing the ignition timing in stages for a certain period of time from the time of detection of the acceleration state.

Next, FIG. 7 shows the contents of the interrupt routine activated by the output signal of the throttle sensor 80.

This interrupt routine is executed by the throttle sensor 80 as described above.
Two types of interrupt signals 19e are output from.

It is activated at the falling edge of the 19f pulse. In the figure, when the interrupt routine is started in step 200, it is determined in the next step 200 whether or not the current 11-in is the same interrupt as the previous one.

will be done. This is a judgment step provided to prevent chattering of the sliding portion 82 of the throttle sensor 80.

If the determination in step 200 is ``Yes'', that is, if chattering occurs in the sliding portion 82, the process jumps to step 208, resets the timer 11AC, and returns to the main routine in step 210.

On the other hand, if it is determined in step 202 that // NO
A determination is made as to whether AC≦25.

If it is determined in step 204 that 1/N O//, the process jumps to step 208, and the same processing as described above is performed.

On the other hand, if the determination in step 204 is /'Yes, in other words, if a sudden acceleration state is detected, the timer TAC1 is reset in step 206, and then the timer TAC is reset in step 208, and the process proceeds to step 210. to return to the main routine.

Next, FIG. 8 shows the contents of the ignition timing control interrupt routine that is activated every 90 degrees before the binary point (90 degrees BTDC).

In the figure, when the interrupt routine is started at step 300, the contents of the timer 'AC' are set at the next step 302.
['Acl>125/E) If yes/no is determined in step 302, then in step 304 the current ignition is set to the previous ignition timing θ■G plus 1°. The time is set to θIG, and the process moves to the next step 306.

In step 306, the ignition timing θIG obtained in step 304 is compared with the basic ignition advance angle θBASE. If it is determined in step 306 that θBASE < θIG, and in step 302, l/N O
If it is determined that //, the process moves to step 308. In step 308, the basic ignition advance angle θBASE is set as the current ignition timing θIG, and in step 310, the routine proceeds to another routine. On the other hand, if it is determined in step 306 that it is Not, or if it is determined that θBASE≧θIG, the routine jumps to the null-up 310 and proceeds to another routine.

FIG. 9 shows control characteristics in the ignition timing control method according to the present invention, and at time 1.p) in the figure. When an acceleration state is detected in , the engine load Q/N is as shown in the figure (
As shown in Fig. B), the ignition timing θIG is temporarily controlled to the retarded side according to the output of the airflow meter, and then to the advanced side, as shown in Fig. 3(C). In this case, in the conventional case, the ignition timing is gradually advanced as shown by curve B, but in the present invention, the ignition timing θIG is stopped immediately after sudden acceleration is detected, and the ignition timing θIG is controlled within a certain period of time immediately after the acceleration state is detected. In order to control the setting to a constant value (for example, the basic ignition advance angle θBASE), the steady state engine load Q/N is
It can be seen that the ignition timing quickly returns to the one that matches the ignition timing. The characteristics of the engine speed at this time are shown in FIG. 5 (5). In the figure (5), curve A shows the case of the present invention, and curve B shows the case of the conventional case.

〔Effect of the invention〕

According to the present invention, it is possible to improve engine output and fuel efficiency.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of an engine control device to which the present invention is applied, FIG. 2 is a block diagram showing a specific configuration of the control circuit 34 in FIG. 1, and FIG. 3 is an explanation showing the configuration of a throttle sensor 80. Figure 4 is a flowchart showing the contents of the interrupt routine activated every 10 CAs, Figure 5 is a flowchart showing the contents of the time coincidence interrupt routine,
FIG. 6 is a flowchart showing the contents of a timer interrupt routine that is started every 4 msec, FIG. 7 is a flowchart showing the contents of an interrupt routine that is started by the output signal of the throttle sensor 80, and FIG. A flowchart showing the contents of the interrupt ignition timing control interrupt routine started every BTDC, and FIG. 9 is a characteristic diagram showing the control characteristics of the ignition timing control method according to the present invention in relation to the conventional example. 2... Air plow meter, 6... Throttle valve, 2
8... Igniter, 30... Cylinder discrimination sensor, 32
... Jinjin rotation angle sensor, 34... Control circuit, 36
...RA to E M-, 38-ROM, 4 0=
-CPU, 8 0-20 Tsuttle sensor agent Tatsuyuki Unuma (and 2 others) No. 3111 No. 41'4 100゛5 Fig. 7 Fig. 8

Claims (2)

[Claims] (1) An engine ignition timing control method that retards the ignition timing in response to acceleration and then gradually advances the ignition timing, which is characterized in that the ignition timing is set to a predetermined value immediately after a sudden acceleration condition is detected. . (2) The engine ignition timing control method according to claim (1), wherein the predetermined value is a basic ignition timing determined by engine speed and intake air amount.