JPS603480A - Method of controlling ignition timing in engine - Google Patents

Abstract

PURPOSE:To prevent output from reduction in the beginning of quick acceleration by delaying ignition timing a predetermined amount of quick acceleration delay when the occurrence of knocking is detected during the quick acceleration of an engine. CONSTITUTION:An electronic control circuit 34 controls ignition timing to delay the ignition timing by a predetermined amount of quick acceleration delay when the occurrence of knocking is detected during acceleration of an engine. That is, whether or not the engine is under the quick acceleration is judged from intake air amount per one revolution of the engine. In the quick acceleration is judged whether or not the knocking occurs. When the knocking is detected, the ignition timing is delayed by the predetermined quick acceleration delay. Thus, the output in the beginning of quick acceleration can be prevented from reduction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine ignition control method, and more particularly to an improvement in an ignition timing control method for retarding the ignition timing by a predetermined amount when a sudden engine acceleration state is detected.

Conventionally, an air flow meter is used to measure the total amount of intake air taken into the engine, and an 02 sensor is used to detect the residual oxygen concentration in the exhaust residue, and the fuel injection pattern is controlled to bring the air-fuel ratio of the mixture to the required value. An engine that controls ignition timing by increasing or decreasing the amount of retardation from a predetermined basic ignition advance angle based on the amount of intake air and engine speed, depending on engine operating conditions such as occurrence of non-king. It has been known. In this engine, when the throttle valve is suddenly opened due to sudden acceleration from the throttle valve closed state, the pressure between the throttle valve and the engine combustion chamber is lower than the pressure between the air flow meter and the throttle valve when the throttle valve is closed, so the air flow is reduced. The air between the meter and the throttle valve flows into the engine at once, and momentarily more air is supplied to the engine than the amount of intake air measured by the airflow meter. As a result, the air-fuel ratio becomes leaner than the required value, and the actual engine load becomes higher than the measured load expressed by the ratio of the intake air amount to the engine speed, making non-king more likely to occur.

Therefore, in the past, a throttle sensor was installed on the throttle valve to detect sudden engine acceleration from the throttle valve's sudden opening state, and when the engine suddenly accelerated, it immediately retarded the ignition Mk by a predetermined amount, and the amount of intake air was accurately adjusted. Once the airflow meter is used to measure the angle, the amount of retardation is completely reduced. However, in this conventional method, the ignition timing is retarded when the engine suddenly accelerates even if no knocking actually occurs, resulting in an unnecessary drop in output and a problem in that the acceleration feeling deteriorates. In order to solve this problem, we set a total amount of sudden acceleration retardation that is set to a predetermined value when sudden engine acceleration is detected and then decrease, and use this sudden acceleration retardation amount when the occurrence of knocking is detected. It has been proposed to completely retard the ignition timing. The reason why the sudden acceleration retardation amount is decreased is because the amount of intake air that is not measured by the air flow meter decreases as time passes after acceleration. However, in this method, since the amount of retardation is reduced, there is a problem that when non-king actually occurs, the amount of retardation is insufficient and it becomes impossible to prevent the occurrence of knocking.
Also, as a countermeasure, if the initial value of the sudden acceleration retard amount is increased, the output will decrease when knocking occurs at the beginning of acceleration. There was a problem.

The present invention has been made to solve all of the above-mentioned problems, and is capable of controlling the ignition timing to completely prevent the occurrence of knocking, which often causes a lack of output during sudden acceleration, and the knocking of bales where knocking has been detected. The entire purpose is to provide a method.

In order to achieve the above object, the present invention sets a sudden acceleration retardation amount that fully retards the ignition timing when sudden engine acceleration is detected, and maintains it until the occurrence of knocking is detected. The amount of sudden acceleration retardation that is maintained from the predetermined basic ignition advance angle when knocking is detected?
The configuration is such that the ignition timing is controlled based on the subtracted value.

According to the fourth aspect of the present invention, the ignition timing is retarded by using the sudden acceleration retardation amount at the time when knocking occurs during sudden acceleration, so that a decrease in output at the initial stage of sudden acceleration does not occur, and knocking is prevented. This has the effect of preventing the occurrence of □.

Next, an example of an engine to which the present invention is applied is shown in FIG. This engine is controlled by an electronic control circuit such as a microcomputer, and as shown in the figure, is equipped with an air flow meter 2 as an intake air amount sensor downstream of an air cleaner (not shown). The air 70-meter 2 includes two conven motion plates rotatably provided in the damping chamber and a potentiometer 2B that detects the opening of the compensator Yomp L/-12A.
It is composed of. Therefore, the intake rough air amount is detected from 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 wall air.

A throttle valve 6 is disposed downstream of the air flow meter 2, a throttle sensor 22 for detecting sudden acceleration of the engine is attached to the throttle valve 6, and a surge tank 8 is disposed downstream of the throttle valve 6. It is being This surge tank 8 has an intake manifold 1
0 is connected, and this intake manifold 10
A fuel injection valve 12 is arranged to protrude inward. The intake manifold 10 is a combustion chamber 1 of an engine body 14.
4A, 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. In the engine body 14, there is a notching sensor which is composed of a microbond or the like and which detects engine activation due to combustion.
is provided. Incidentally, 20 spark plugs are provided, and 24 is a cooling water temperature sensor that detects the engine cooling water temperature.

A spark plug 20 attached to the engine body 14 is connected to a distributor 2G, and a distributor 26 is connected to an igniter 28. The distributor 26 is provided with a cylinder discrimination sensor 30 and an engine rotation angle sensor 32, each consisting of a big amplifier fixed to the distributor housing and a signal rotor fixed to the distributor shaft. This cylinder discrimination sensor 3o outputs a cylinder discrimination signal to the electronic control circuit 34 constituted by a microcomputer etc., for example, every 720 degrees of crank angle, and the engine rotation angle sensor 32 outputs a cylinder discrimination signal, for example, every 30 degrees of crank angle M3m. '4 Position signal is output to the all-electronic control circuit 34.

As shown in FIG.
It has a letter-shaped rotating piece 80 2). At the base end of the rotating piece 80, an IlI piece 8 is provided which extends in the direction of the distal end of the rotating piece 80.
One end of the first contact 82 is fixed so as to be in close contact with the tip of the first contact 82. Furthermore, one wing of a second contact 86 is fixed to the tip of the rotating piece 80 via an insulating material 84 so as to be parallel to the first contact 82 . This second contact 86 is grounded. A comb-shaped first electrode 88 and a comb-shaped second electrode 90 are arranged so that the teeth of the other electrode are interposed between the teeth of the electric horn, and The first electrode 88 and the second electrode 90 are arranged as follows.
One end of each is connected to a power source via a resistor 92 and a resistor 94, and is also connected to the electronic control circuit 34.

This throttle sensor is connected to the direction in which the throttle valve 6 opens (
When the rotating piece 80 is rotated in the direction of the arrow in the figure), the rotating piece 80 rotates 7 and the first contact 82 and the second contact 8 are rotated.
6, the tip of the first contact 82 alternately contacts the first electrode 88 and the second electrode 90 and is grounded, so that a pulse signal with a waveform as shown in FIG. 3 is output. . Furthermore, when the throttle valve is rotated in the closing direction,
Since the first contact 82 and the second contact 86 are rotated in a non-contact state, a pulse signal (no output is output).

Electronic control circuit: 34 is a random circuit, as shown in Figure 4.
Access memory (RAM) 36, read-only
Memory (ROM) 38, central processing unit (CPU)
40, a clock (CLOCK) 41, a first input/output port 42, a second input/output port 44, a first output port 46, and a second output port 48,
AM36, RoM'! □) 38, CPU 40, CLOCK 41, first output port 42, second input/output port 44, first output port 4
6 and the second output port 48 are connected to a node 50 such as a data path or a control node. :ρ connected.

The first input/output boat 42 includes a sofa (not shown).
, multiplexer 54, analog-digital (A/D
) The air flow meter 2, the cooling water temperature sensor 24, the intake air temperature sensor 4, etc. are connected via the converter 56. This multiplexer 54 and A/D converter 56 are
It is controlled by a control signal output from the first passenger boat 42. A first electrode 88 and a second electrode 90 of the throttle sensor 22 are connected to the second input/output boat 44, and a cylinder discrimination sensor 30 and an engine rotation angle sensor 32 are connected to the second input/output boat 44 via a waveform shaping circuit 64. is connected. The knocking sensor 18 is connected to the second input/output port 44 via a bandpass filter 60, a peak hold circuit 61, a channel switching circuit 66, and an A/D converter 68. ) The filter 0 is connected to a channel switching circuit 66 via an apportioning circuit 63. This channel switching circuit 66 is connected to either the output of the peak hold circuit 61 or the output of the integrating circuit 63.
A control signal for inputting to the second input/output port 44
A reset signal and a gate signal are input to the peak hold circuit 61 from the second input/output port 44.
It is input from.

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 gauge 1 injector 12 via a drive circuit 72 (i).

The ROM 38 of the electronic control circuit 34 stores in advance a map of the basic ignition advance angle determined by the amount of intake air per engine rotation and the engine rotation speed, a control program, etc., and the air flow meter 2 and the engine rotation angle. sensor 3
The basic ignition advance angle is read based on the signal input from the cooling water temperature sensor 24 and the intake air temperature sensor 4.
The basic ignition advance angle is corrected and the igniter 28 etc. are controlled by various signals including signals from the ignition engine.

Next, an embodiment in which the present invention is applied to the engine as described above will be described in detail. In the detailed explanation of the present invention, in order to avoid complication, the explanation will be made using the most convenient numerical values, but the present invention is not limited to these numerical values, and the present invention is not limited to these numerical values. value is selected. This embodiment calculates a correction retard amount θKf that retards the ignition timing when the occurrence of knock/knock is detected and advances the ignition timing when the occurrence of knocking is not detected. Rapid acceleration retardation amount θACk that retards the ignition timing when detected
Set it and hold it at the point where the occurrence of knocking is detected, and when the occurrence of knocking is detected during rapid engine acceleration, change the preset basic ignition advance angle θB A S g to the corrected retardation amount θ. The ignition timing is controlled based on the value obtained by subtracting 1 from the retained rapid acceleration/retardation amount θAC.

Figure 5 is a Mizuko version of the routine that determines sudden acceleration and sets the sudden acceleration retardation amount θAC. It will be done. In step 100, it is determined whether or not the interrupt is caused by the fall of the output signal of the first electrode. If the interrupt is caused by the first electrode, it is determined in step 101 whether or not the flag FeO value is 0. If so, in step 103, the value of the flag Fe is inverted. If it is not an interruption by the first electrician, the flag Fe is set in step 102.
It is fully determined whether the O value is 1 or not, and if the flag FeO value is 1, the flag FeO value is inverted in step]03. On the other hand, when the flag FeO value is 1 at step 101kl and when the flag FeO value is O at step 102, @ is
Proceed to 06.

In step 104, the count value TAC of the acceleration timer is incremented in step 117 of FIG. 7, which is executed at 4 rnsec%.
= 100m5ec) or less to determine whether or not there is sudden acceleration. This acceleration timer counts the time between the fall of the signal output from the first electrode and the fall of the signal output from the second electrode. This indicates sudden acceleration.When the count value TAC is 25 or less, it is determined that there is a sudden acceleration, and in step 105, the value of the sudden acceleration retardation amount θAC is stored as 8°CA in a predetermined area of the RAM. In step 106, count value TAck is cleared.Count value T
When AC exceeds 25, the switch's step is 106.
Clear the count value TAck with .

FIG. 6 shows a process executed on the correction retard amount θ regarding non-king. In step 107, it is determined whether or not the knocking control region 1 is reached by determining whether the amount of intake air per engine/engine revolution is equal to or greater than a predetermined value. If the knocking control region is within the knocking control region, in step 109, the explosion stroke of each cylinder is set within a predetermined crank angle range (for example, 10°).
CA ATI) C ~ 50° CA ATDC), the filter 0, the peak hold circuit 61, the channel switching circuit 66 and the A/Di switch 68
Predetermined frequency band (7 to 8 KH2) input through
The peak value a of the electric signal of to a constant'
It is determined whether or not knocking has occurred by comparing the multiplied determination level kb with the determination level kb. If it is determined that the non-king occurs from 1 to 1, the knocking flag FK is set-i in step 111, and the
2, the value 'z of the correction retard amount θ is increased by 0.4°CA. On the other hand, if it is determined that knocking does not occur, the value of the correction retard amount θ is set to 0.0 in step 110.
Reduce by 8°CA. In the next step 113, it is determined whether or not the knocking flag FK is set.
If set, step 114 and step 11
6, the basic ignition advance angle θBAS read from the ROM
The effective ignition advance angle θjg can be obtained by subtracting the sum of the sudden acceleration retard amount θAC and the corrected retard amount θ from W.

Here, θKk may not be subtracted under the conditions for θACk subtraction. On the other hand, if the knocking flag FK is not set, step 115 and step 1
16, the correction retard amount θ is calculated from the basic ignition advance angle θBASE.
The value obtained by subtracting K is set as the effective ignition advance angle 04g.

If it is determined in step 107 that it is not in the knocking control 11 region, the value of the corrected retard amount θ is set to 0 in step 108, and the effective ignition advance angle vjg is determined in steps 115 and 116.

Therefore, the ignition advance angle θj determined/executed as described above is
In other routines, the igniter is turned off so that it is ignited with g.

FIG. 7 shows a routine for counting the acceleration timer and attenuating the correction retardation amount θ.
It is executed during interrupt processing for each m5ec. Step 1
The count value TAcil of the acceleration timer is incremented at step 17, and it is determined whether the count value TAC is less than 30 at step 118. When the count value TAC exceeds 30, the count value TAC is set to 30 at step 119. , which prevents timer overflow.

In the next step 120, it is determined whether or not the knocking flag FK is set, and if it is set, in step 121, the rapid acceleration M-Kakutaku: DAC value'! f”0.1
1-'CA decrease. In the next step 122, it is determined whether the sudden acceleration retardation amount OAc is equal to or greater than 00CA, and if the sudden acceleration retardation %10AC is a value of 9, then in step 123 the acceleration retardation amount θAc is determined. is read as 00CA, and the knocking flag PK is set at step 124.
f Reset. When the knocking flag FK is turned off and the sudden acceleration retardation amount θAC is 0°
If it is CA or higher, the routine advances to step 17.

As mentioned above, in step ], 05, the sudden acceleration retardation amount θA
What if the value of C is set and the Metsukink flag FK is sent in step 120? ■n [0 only if
．． Rapid acceleration retardation amount θAC at a rate of 1°CA74msec
Therefore, 8° CA is held as the value of the sudden acceleration retardation amount when sudden acceleration is detected (1) and the occurrence of 7-tracking is detected.

FIG. 8 shows a timing diagram of this embodiment. In the nose kink control region, the time between the fall of the output of the first electrode and the fall of the output of the second electrode is less than 100 m5ec, resulting in a sudden acceleration state! If it is determined, the sudden acceleration retardation amount θAC
rises as shown by the broken line. Then, this rapid acceleration retardation amount θAC is held until the knocking flag FK is set, and is decreased at a rate of t<0-1°CA/4m5ec.

Next, another embodiment of the present invention will be described using FIG. 9. The non-implementation flag j is set to 1 so that the acceleration retard amount θACk is held for a certain period of time without being decreased after the occurrence of 7' soching is detected. Maroo, in Figure 9 ='Gi゛C
Figure 7! : Iff+parts are given the same reference numerals and their explanations are omitted. The routine shown in FIG. 9 is an interrupt routine that is executed every 4 rnsec.

If it is determined in step 120 that the knocking flag FK has been reset, then in step 126 the timer count value TAct'fi:50 (=200
m5ec) and proceed to the next routine.

When the knocking flag FK is set, the count value Tact is decremented by one in step 127, and it is determined in step 128 whether the count value Tact is less than or equal to 0. When the count value TAct exceeds θ, the process proceeds to the first routine, and the count value TAct becomes OJ.
In the case of O-1 below (d, in step 129, the count value T
Acti5Q, and in step 130, the sudden acceleration retardation amount θA
The values of C are all set to 0°CA, and the nogging flag FK'f is reset in step 13].

FIG. 10 shows a timing diagram of the above-mentioned failed embodiment.

In this embodiment, the sudden acceleration retardation amount θAc is set at the time when the knocking flag F1: is set after sudden acceleration is detected, and when the knocking flag FK/ is set at 200 seconds after the sudden acceleration is detected.
It is held at 8° CA for m5ec.

In addition, although the engine in which the basic ignition advance angle is determined according to the amount of intake air per engine revolution and the engine speed has been described above, the present invention sets the basic ignition advance angle according to the intake pipe pressure and the engine speed. It is also possible to apply engine specifications that determine the

In this case, the intake pipe pressure is detected by a pressure sensor provided downstream of the throttle valve.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing an example of an engine to which the present invention is applied, Fig. 2 is a circuit diagram showing i]' = thin of the throttle sensor, and Fig. 3 is a line showing the signal waveform output from the throttle sensor. 4 is a block diagram showing details of the electronic control circuit of FIG. 1, and FIG. 5 is an interrupt routine γ range θic9 executed by the signal of the throttle sensor in the embodiment of the present invention. Fig. 6 is a flowchart showing the routine in which the above-mentioned fruit is interrupted by 900B'f'DC in the example, and Fig.
CM interrupt routine flowchart, Figure 8 is above BL
Fig. 9 is a flowchart showing the interrupt routine of 4+n5ec m in another embodiment of the present invention, and Fig. 10 shows the timing of the above embodiment. It is a line diagram. 6...Throttle valve, 18...Knotskink' sensor, 22...Throttle sensor, 34...Pelectronic fi+
lI 6I al tract. Agent Tatsuyuki Unuma (and 1 other person) Figure 8 Figure 9

Claims (1)

[Claims] (1) When sudden engine acceleration is detected, the ignition timing is fully retarded.The full sudden acceleration retardation amount is set and held until the occurrence of non-king is detected, and when the occurrence of non-king is detected during sudden engine acceleration. An engine ignition timing control force mem that completely controls ignition timing based on a value obtained by subtracting the retained rapid acceleration retardation amount from a predetermined basic ignition advance angle.