JPS59145364A - Method of controlling ignition timing for internal- combustion engine - Google Patents

Abstract

PURPOSE:To prevent reduction in output and improve performance of acceleration, by advancing ignition timing upon sensing of rapid acceleration. CONSTITUTION:There are provided a suction air temperature sensor 14 incorporated in an air flow meter 12 for sensing flow of suction air, a throttle valve 16 openably interlocked with an acceleration pedal (not shown) for controlling flow of suction air, and a throttle sensor 18 for sensing an opening degree and a changing speed of the throttle valve. There are further provided an ignition coil 31 for converting an ignition primary signal generated by an igniter 30 to an ignition secondary signal of high pressure, a cylinder decision sensor 34 and a rotary angle sensor 36 incorporated in distributor 32 for outputting a cylinder decision signal and a rotary angle signal, and an engine coolant temperature sensor 38 provided on a cylinder block 10B of an engine 10. Desired values of these sensor outputs are operated in an electronical control unit (ECU) 40, and ignition timing is advanced upon sensing of rapid acceleration to improve performance of acceleration.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition timing control method for an internal combustion engine, and more particularly, to an ignition timing control method based on an intake air amount and an engine rotation speed, which is suitable for use in an automobile engine equipped with an electronically controlled ignition timing control device. This invention relates to an improvement in an ignition timing control method for an internal combustion engine, including a procedure for determining timing.

In spark-ignition internal combustion engines such as gasoline engines, the ignition timing is known to have a close relationship with the engine's output performance and fuel efficiency, and the ignition timing is always optimal depending on the engine operating condition. In order to control the ignition timing, a so-called electronically controlled ignition timing control device has been put into practical use, which calculates the ignition timing from the engine load such as intake air amount and the engine speed, and then controls the actual ignition timing to obtain the optimum ignition timing. has been made into

In such an electronically controlled ignition timing control device, when detecting the engine load from the intake air amount, an air flow meter is generally used to measure the intake air amount. Due to an increase in the amount of intake air during rapid acceleration, there is a phenomenon in which, after the throttle valve is suddenly opened, a value of the amount of intake air that is temporarily larger than the actual amount of intake air is output. On the other hand, in electronic ignition timing control as described above, the ignition timing is usually delayed as the load increases, where the amount of intake air increases.
Due to the above-mentioned phenomenon, the ignition timing becomes temporarily over-retarded, resulting in a problem of insufficient output and deterioration of fuel efficiency.

The present invention has been made to solve the above-mentioned conventional problems, and it is possible to obtain appropriate ignition timing even during sudden acceleration when the air 70-meter erroneously outputs an excessive amount of intake air. Therefore, it is an object of the present invention to provide an ignition timing control method for an internal combustion engine that can prevent a decrease in output, ensure acceleration performance, and improve fuel efficiency.

The present invention provides a first method for controlling ignition timing of an internal combustion engine.
As the summary is shown in the figure, the above-mentioned method includes a procedure for determining the ignition timing from the intake air amount and engine speed, a procedure for detecting sudden acceleration, and a procedure for advancing the ignition timing after detecting the sudden acceleration. The purpose has been achieved.

Further, after the sudden acceleration is detected, the ignition timing is advanced after a predetermined time delay, thereby preventing knocking due to over-advancement at the initial stage of acceleration.

Alternatively, after the sudden acceleration is detected, the ignition timing is advanced when an increase in the amount of intake air or the engine rotational speed is detected, thereby similarly preventing knocking due to overadvance angle at the initial stage of acceleration. be.

According to the present invention, the ignition timing is advanced during sudden acceleration when the air flow meter erroneously outputs a temporarily excessive amount of intake air, thereby preventing a drop in output and ensuring acceleration performance, as well as ensuring fuel efficiency. Performance can be improved.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an automobile engine equipped with an intake air amount sensing type electronic control device, in which the ignition timing control method for an internal combustion engine according to the present invention is adopted, will be described in detail below with reference to the drawings.

The first embodiment of the present invention, as shown in FIG.
an intake air temperature sensor 14 for detecting intake air; a throttle valve 16 that opens and closes in conjunction with an accelerator pedal (not shown) disposed on the driver's seat for controlling the flow rate of intake air; A throttle sensor 18 for detecting the opening degree of the throttle valve 16 and its rate of change, a surge tank 20 for preventing intake air interference, and an intake boat for each cylinder arranged in an intake manifold 22. an injector 24 for injecting pressurized fuel; a spark plug 26 for igniting the air-fuel mixture introduced into the re-engine combustion chamber 10A; an exhaust manifold 28; an igniter 30 for generating an ignition-following signal; An ignition coil 31 for converting the ignition signal generated by the igniter 30 into a high-voltage ignition secondary signal, and for distributing the ignition secondary signal generated by the ignition coil 31 to the spark plug 26 of each cylinder. , a destroyer 32 having a destroyer shaft 32A that rotates in conjunction with the crankshaft of the engine 10, and a cylinder discrimination sensor 34 built into the destroyer 32 for outputting a cylinder discrimination signal and a rotation angle signal, respectively. and a rotation angle sensor 36, a water temperature sensor 38 disposed in the cylinder block 10B of the engine 10 for detecting the engine cooling water temperature, and an intake air amount Q detected from the output of the air flow meter 12 and the rotation angle sensor. The basic ignition timing θbase is determined from the engine speed N detected from the output of the throttle sensor 18, and when sudden acceleration is detected from the output of the throttle sensor 18, the basic ignition timing is set a predetermined number of times, for example, 50 times, after the sudden acceleration is detected. Advance θbase by a predetermined value, for example, 5℃A,
Outputting an ignition command signal to the igniter 30, and
An electronic control unit (hereinafter referred to as ECU) determines the fuel injection amount according to the intake air amount, engine speed, engine cooling water temperature, etc. and outputs a valve opening time signal to the injector 24.
It is composed of >40, which is called , and .

As shown in detail in FIG. 3, the throttle sensor 18 has a movable contact 1 that rotates ξ in conjunction with the throttle valve 16.
8A, an idle contact 18B disposed corresponding to the fully open position of the throttle valve 16 for detecting that the throttle valve 16 is in the fully closed state, and detecting the rate of change in the opening of the throttle sensor 18. a pair of comb-shaped contacts 18C118D arranged in combination with each other for the purpose of the present invention.

As shown in detail in FIG. 4, the ECU 40 includes a central processing unit (hereinafter referred to as CPU) 40A composed of, for example, a microprocessor for performing various arithmetic operations, and a clock circuit 40B that generates various clock signals. , a read-only memory (hereinafter referred to as ROM) 40 for storing control programs, various data, etc. in advance;
C, and a random access memory (hereinafter referred to as RAM) for temporarily storing calculation data etc. in the CPU 40A.
400, the air 70-meter 12 output, and the intake temperature sensor 14.
a multiplexer 40E for sequentially taking in analog signals such as output and the output of the water temperature sensor 38; and an analog-to-digital converter (hereinafter referred to as A/D converter) 40F for converting the output of the multiplexer 40E into a digital signal. , input/output port 4 for receiving the A/D converter 40F output
0G, a shaping circuit 40H for waveform shaping the outputs of the cylinder discrimination sensor 34 and the rotation angle sensor 36, and the shaping circuit 40H.
an input/output boat 401 for receiving the output and the output of the throttle sensor 18; and an output boat 40 for outputting an ignition command signal to the igniter 30 via the drive port-path 40J according to the calculation result of the CPU 40A. The same <CPU 4. It is comprised of an output boat 40M for outputting a valve opening time signal to the injector 24 via a drive circuit 40L according to the calculation result of the OA, and a common bus 4ON connecting each of the component devices.

The action will be explained below.

Detection of sudden acceleration in this embodiment is carried out using comb-like contacts 18c and 1 of the throttle sensor 18 as shown in FIG.
This is executed by an interrupt routine that is entered at the rising edge of the 8D output. That is, step 1 is entered at step 102 when the output of the comb contact 18C or 18D rises, and it is determined whether or not it is the same interrupt as the previous one. If the determination result is negative, that is, if it is determined that the opening degree of the throttle valve 16 has changed by a predetermined amount or more, the process proceeds to step 104, and in an interrupt routine every 4 milliseconds (not shown), an interrupt is executed every 4 milliseconds. It is determined whether the count value of the counter Tac, which is incremented by increments, is less than or equal to a predetermined value, for example, 25.

If the determination result is positive, that is, if it is determined that the opening of the throttle valve 16 has changed by a predetermined amount or more within 100 milliseconds, the process proceeds to step 106, and it is determined that the sudden acceleration is occurring. Set the flag Fac indicating this. After the step 10611 is completed, or if the judgment result of the above step 102 is positive or the judgment result of the above step 104 is negative, the process advances to step 108, and the counter Ta is
This routine is completed by clearing c, and the routine returns to the main routine.

Control of the ignition timing according to the presence or absence of sudden acceleration detected in the interrupt routine shown in FIG. 5 is executed according to the 90 DEG BTDC interrupt routine shown in FIG. 6.

That is, when the engine rotation angle detected from the output of the rotation angle sensor 36 is 90° BTDC, step 20
2, the intake air amount per engine revolution at that time Q
, , / Calculate the basic ignition timing θbase from N and the engine rotation speed N. Next, the process proceeds to step 204, where it is determined whether the sudden acceleration detection flag FaC is set. If the determination result is negative, that is, if it is determined that there is no rapid acceleration, the process proceeds to step 206, where the basic ignition timing θbase obtained in step 202 is used as the final ignition timing θig, and then step 208 Then, the counter Tac for counting the number of advance angles during sudden acceleration is cleared.

On the other hand, if the determination result in step 2'04 is positive, that is, if it is determined that rapid acceleration is occurring, the process proceeds to step 210, where it is determined whether or not the counter TaC1 is OC. If the determination result is positive, that is, if it is determined that this is the first advance angle after the sudden acceleration was detected, the process proceeds to step 212, and an initial value of 50 is entered into the counter Tac. Next, the process proceeds to step 214, where the sudden acceleration detection flag FaC is reset. After step 214, or
If the result of the determination in step 210 is negative, the process advances to step 216, where the basic ignition timing B base adjusted in step 202 is advanced by a predetermined value, for example, 5°C A, as the final value. ignition timing θig. Next, the process proceeds to step 218, where the counter Tac is counted down by 1, this routine is ended, and the process proceeds to the next routine.

Ignition timing control based on the ignition timing θ1g determined by the 90 DEG BTDC interrupt routine shown in FIG. 6 is executed according to the 30 DEG 8 interrupt routine shown in FIG. That is, step 302 is entered every 30° C.A, and the engine rotation speed N is determined from the elapsed time between crank angle signals output from the rotation angle sensor 36. Next, the process proceeds to step 304, in which the number of interruptions after the cylinder discrimination signal output from the cylinder discrimination sensor 34 is input is counted, and a flag indicating the current crank angle is set. Next, the process advances to step 306, where the current interrupt is 9.
0' Determine whether it is a BTDC interrupt. If the determination result is positive, the process proceeds to step 308, where the time at which the igniter 30 should be turned on is determined from the final ignition timing θig and the current time, and a time coincidence interrupt is set.
Reset the igniter on flag Figon. Furthermore, if the determination result in step 306 is negative,
Proceed to step 310, and the current interrupt is 60' BTD.
It is determined whether it is a C interrupt.

If the determination result is positive, the process advances to step 312, and the igniter 3 is calculated from the final ignition timing θ19 and the current time.
Find the time when 0 is turned off, set a time coincidence interrupt, and reset the igniter on flag F igon. After step 312 is completed, or if the determination result in step 310 is negative, this routine is ended and the process returns to the main routine.

The on/off control of the igniter 30 based on the time coincidence interrupt set in the 30'CA interrupt routine shown in FIG. 7 is executed according to the time coincidence interrupt routine as shown in FIG. That is, when the times match, step 402 is entered, and it is determined whether the igniter-on flag F igon is set. If the determination result is positive, the process proceeds to step 404, where the igniter 30 is turned on and the process returns to the main routine.

On the other hand, if the determination result in step 402 is negative, the process proceeds to step 406, where the igniter 30 is turned off and the process returns to the main routine.

In this embodiment, after the acceleration is detected, the ignition timing is advanced by a predetermined value of 5°C for 50 ignitions, so the program is relatively simple.

Next, a second embodiment of the present invention will be described in detail.

This embodiment has an air 70-meter 12, an intake air temperature sensor 14, a throttle sensor 18, an injector 24, a spark plug 26, and an igniter 3012 similar to the first embodiment.
Ignition coil 31, destroyer 32, cylinder discrimination sensor 34, rotation angle sensor 36, water temperature sensor 38 ECU 4
In an automobile engine 10 equipped with an intake air-sensing electronic control device having a temperature of 0, etc., the ignition timing is advanced within the excitation ECU 40 after a predetermined time delay after sudden acceleration is detected. The other points are the same as those of the first embodiment, so the explanation will be omitted.

The operation of the second embodiment will be explained below.

The sudden acceleration detection in this embodiment is executed by the skin-in routine as shown in FIG. 5, as in the first embodiment.

The ignition timing is controlled according to the presence or absence of sudden acceleration detected in the interrupt routine shown in FIG. 90° BTDC interrupt routine.

That is, the process enters step 502 in FIG. 9 every 4 milliseconds to determine whether the sudden acceleration detection flag Fac has been reset. If the determination result is negative, that is, if the sudden acceleration detection flag Fac is set, step 50
Proceed to step 4 and reset the sudden acceleration detection flag Fac. Next, the process proceeds to step 506, where an initial value of 25 is entered into the counter T (lc2) that counts the delay time after sudden acceleration is detected, and at step 508, the counter Tac3 is set to count the time during which the ignition timing is advanced. An initial value of 50 is entered in , and this routine ends.

On the other hand, if the determination result in step 502 is positive, the process proceeds to step 510, where the counter TaC2 is counted down by one. Next, the process proceeds to step 512, where it is determined whether the count value of the counter 7ac2 has become O or less. If the decision result is positive, that is, the predetermined delay time,
For example, when it is determined that 100 milliseconds have elapsed, the process proceeds to step 514, where the counter Tac2 is cleared, and at the same time, the counter Tac3 is counted down by 1 at step 516. Next, the process proceeds to step 518, where it is determined whether the count value of the counter TaC5 has become less than or equal to O. When the determination result is positive, that is, when it is determined that a predetermined advance time, for example 200 milliseconds, has elapsed,
Proceeding to step 520, the counter TaC5 is cleared and this routine ends. Further, if the determination result in step 512 or 518 is negative, this routine is immediately terminated.

The ignition timing is controlled according to the state of the counter Tac3 that is counted down by the 4 millisecond interrupt routine shown in FIG.
Executed by the DC interrupt routine. That is, if the crank angle is 90' BTDC, step 6
02, and the basic ignition timing θbase is calculated from the intake air port Q/N per engine rotation and the engine rotational speed N at that time. Then proceed to step 604,
It is determined whether the count value of counter daa3 is greater than 0 or not. If the determination result is positive, that is, if it is determined that the predetermined delay time of 100 milliseconds has elapsed after sudden acceleration was detected, and within the predetermined time of 200 milliseconds for advancing the ignition timing, step Proceeding to step 606, the basic ignition timing θbase obtained in step 602 is set to a predetermined value of 5.
The value advanced by °CA is set as the final ignition timing θig.

On the other hand, if the determination result in step 604 is negative, the process proceeds to step 608, and step 602
The basic ignition timing θbase obtained in step 2 is used as the final ignition timing θig. After step 606 or 608, the process proceeds to state 610, calculates the time at which the igniter 30 should be turned on based on the ignition timing θig, the current time, and the current crank angle, sets a time coincidence interrupt, and ends this routine. .

Incidentally, in this embodiment, the setting of the time at which the igniter 30 is turned off and the on/off control of the igniter 30 by the time coincidence interrupt routine are the same as in the first embodiment, so a description thereof will be omitted.

In this example, the engine rotational speed N1 during sudden acceleration is determined by the intake air amount per engine revolution Q, /N (solid line A) determined from the air flow meter output, and the engine according to the intake air amount actually taken into the engine. Intake air amount per revolution Q, /N (dotted chain line B), final ignition timing θi
FIG. 11 shows examples of changes in g and the opening degrees of the throats 1 to 1. For comparison, it is clear that the engine rotational speed rises earlier than the conventional example shown by the broken line C in FIG. 11, and good acceleration performance is obtained.

Next, a third embodiment of the present invention will be described in detail.

This embodiment has an air 70-meter 12, an intake air temperature sensor 14, a throttle sensor 18, an injector 24, a spark plug 26, an igniter 30, an ignition coil 31, a distributor 32, and a cylinder discrimination sensor 34, which are similar to the first embodiment. , rotation angle sensor 36, water temperature sensor 38, ECU 40
In the automobile engine 10 equipped with an intake air position sensing type electronic control device having the above-mentioned ECU 40, when an increase in the amount of intake air Q/N per engine rotation is detected in the ECU 40 after sudden acceleration is detected, the ignition is activated. This is to advance the timing. The other points are the same as those of the first embodiment, so the explanation will be omitted.

The operation of the third embodiment will be explained below.

The sudden acceleration detection in this embodiment is similar to the first embodiment,
This is executed by an interrupt routine as shown in FIG. 5 mentioned above.

The ignition timing is controlled according to the presence or absence of sudden acceleration detected in the interrupt routine shown in FIG. 5 above, using the 4 millisecond interrupt routine shown in FIG. 90' BTDC interrupt routine.

That is, the routine enters step 7'02 in FIG. 12 every 4 milliseconds to determine whether or not the sudden acceleration detection flag Fac has been reset. If the judgment result is negative, snap 7
04, the sudden acceleration detection flag FaC is reset.

Next, the process proceeds to step 706, where a predetermined plane, for example 0,
2 f2 , /rev wohn value is taken as intake air amount judgment value M. Next, the process proceeds to step 708, where an initial value of 50 is entered into a counter TaC5 similar to that of the second embodiment for counting the time during which the ignition timing is advanced, and this routine ends.

On the other hand, if the determination result in step 702 is positive, the process proceeds to step 710, where counter Tac3 is counted down by 1. The process then proceeds to step 712, where j
It is determined whether the count value of J crank ac3 is less than or equal to 0. If the determination result is positive, the process advances to step 714, where the counter Tac3 is cleared and this routine ends.

On the other hand, if the determination result at step 712 is negative, this routine is immediately terminated.

The ignition timing is controlled according to the state of the counter AC3 and the intake air amount determination value M, which are counted down by the 4 millisecond interrupt routine shown in FIG.
This is executed by a 90° BTDC interrupt routine as shown in FIG. That is, the crank angle is 90' BTDC
If so, step 802 is entered and the basic ignition timing θbase is calculated from the intake air amount Q/N per engine revolution and the engine rotational speed N at that time. Next, the process proceeds to step 804, where it is determined whether the count value of the counter TaC5 is greater than 0 or not. When the determination result is positive, the process proceeds to step 806, and the intake air amount Q/N per engine rotation at that time is determined as step 706 in FIG. 12 above.
It is determined whether the intake air amount is equal to or greater than the intake air amount determination value M obtained in . If the determination result is positive, step 808
Then, the basic ignition timing θbase determined in step 802 is advanced by a predetermined value of 5° C.A, and the value is set as the final ignition timing θig. On the other hand, step 804 or 8
If the determination result in step 06 is negative, the process proceeds to step 810, where the basic ignition timing θ determined in step 802
Let base be the final ignition timing θig. After step 808 or 810 $41Y, the process proceeds to step 812, where the time at which the igniter 30 should be turned on is calculated based on the ignition timing θig, the current time, and the current crank angle.
Set the time match interrupt and end this routine.

Incidentally, in this embodiment, the setting of the time at which the igniter 30 should be turned off and the on/off control of the igniter 30 by the time coincidence interrupt routine are the same as in the first practical example, so a description thereof will be omitted.

In this embodiment, the ignition timing is not advanced immediately after sudden acceleration is detected, but the amount of intake air per engine revolution Q is a predetermined value, 0.2 Jl/'1' e
Since the ignition timing is advanced when the amount of V increases, the ignition timing becomes overadvanced during the repair period.
No knocking occurs.

In this embodiment, the intake air I Q per engine rotation, -' N is used as the determination value, but the determination is not limited to this, and for example, the engine rotation speed N may be used for determination. It is also possible to do so.

As explained above, according to the present invention, it is possible to control the ignition timing to an appropriate level even during sudden acceleration where the air 70-meter temporarily outputs an excessive amount of intake air by mistake. This has the excellent effect of preventing a decrease in output, ensuring acceleration performance, and improving fuel efficiency.

[Brief explanation of drawings]

FIG. 1 is a flow chart showing the gist of the ignition timing control method for an internal combustion engine according to the present invention, and FIG. FIG. 3 is a sectional view including a partial block diagram showing the configuration of the first embodiment, and FIG. 4 is a circuit diagram showing the configuration of the throttle sensor used in the first embodiment. , block diagram showing the configuration of the electronic control unit, fifth
FIG. 6 is a flowchart showing an interrupt routine entered at the rising edge of the output of the comb contact of the throttle sensor for detecting sudden acceleration, and FIG. ' A flowchart showing the BTDC interrupt routine, FIG. 7 is a flowchart showing the 30°C interrupt routine for determining the igniter on and off times, and FIG. FIG. 9 is a flowchart showing an interrupt routine, which is a 4 millisecond interrupt for counting the delay time and ignition advance time after sudden acceleration detection in the second embodiment of the ignition timing control method for an internal combustion engine according to the present invention. FIG. 10 is a flowchart showing the routine, and FIG. 11 is a flowchart showing the 90°B TDC interrupt routine for determining the final ignition timing. FIG. 12 is a diagram comparing and showing changes in the engine rotational speed during acceleration, intake air amount per engine rotation, final ignition timing, and throttle opening, and shows the ignition timing of the internal combustion engine according to the present invention. Flow chart showing a 4 millisecond interrupt routine for determining the intake air amount sensing formula and counting the ignition advance time in the third embodiment of the control method, No. 13
The figure also shows 90 points for determining the R-end ignition timing.
' is a flowchart showing the BTDC interrupt routine. ] 0... Engine, 12... Air flow meter, 16... Throttle valve, 18... Throttle sensor, 24... Injector, 26... Spark plug, 30... Igniter, 31... - Ignition coil, 32... Distributor, 34... Cylinder discrimination sensor, 36... Rotation angle sensor, 40... Electronic control unit (ECU). Agent Takaya Theory (one idiot) Figure 1 Figure 3 Figure 5 Figure 6 Figure 7 Figure 8

Claims (3)

[Claims] (1) An internal combustion engine characterized by including a procedure for determining ignition timing from an intake air amount and engine rotational speed, a procedure for detecting sudden acceleration, and a procedure for advancing ignition timing after detecting sudden acceleration. Ignition timing control method. (2) The ignition timing control method for an internal combustion engine according to claim 1, wherein the ignition timing is advanced after a predetermined time delay after the sudden acceleration is detected. (3) The ignition timing control method for an internal combustion engine according to claim 1, wherein the ignition timing is advanced when an increase in intake air amount or engine rotational speed is detected after the sudden acceleration is detected.