JPS61155658A - Ignition timing controller of internal combustion engine - Google Patents

Abstract

PURPOSE:To avoid production of any unnecessary output reduction at quick acceleration time by performing delay control in accordance with a delay amount which is used at production time of a knocking and resetting the delay amount, which is used at the production time of the knocking, to an initial value when a subsequent knocking is produced. CONSTITUTION:When a quick acceleration condition of an engine 14 is sensed from a sensing signal of a throttle sensor 18, and ignition timing control part 34 sets an initial value of a delay amount which is used for compensating of ignition timing and gradually attenuated with time. When a production of a knocking is subsequently sensed by a knock sensor 22, the control part 34 performs delay control with respect to an ignition timing of the engine in accordance with the delay amount which is used at the produced after said delay control, the delay amount used at the production time of the knocking is reset up to an initial value. The control part performs delay control in accordance with the initial value. Production of a knocking can thereby be sufficiently suppresed without any effect of unnecessary output reduction and deterioration of accelerating feeling at a quick acceleration time.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an ignition timing control device for an internal combustion engine, and in particular, it controls the ignition timing of an engine to be retarded by a predetermined amount during sudden engine acceleration to prevent knocking during sudden acceleration. The present invention relates to an ignition timing control device for an internal combustion engine suitable for suppressing the occurrence of ignition timing.

[Conventional technology]

In vehicle engines such as automobiles, when the engine's ignition timing is retarded during rapid engine acceleration, the pressure between the throttle valve and the engine combustion chamber becomes lower than the pressure between the air flow meter and the throttle valve, and the air flow meter instantly Air in excess of the amount of intake air measured in is supplied to the engine. For this reason, it is known that 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 rotational speed, making knocking more likely to occur.

Therefore, conventionally, when the engine suddenly accelerates, the ignition timing of the engine is retarded by a predetermined amount.

However, with this 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 worsening of the acceleration feeling.

Therefore, the applicant of the present application determined the initial value of the retardation amount, which is the amount of retardation for correcting the ignition timing when the engine suddenly accelerates, and which gradually attenuates as time passes, and when the occurrence of knocking is detected, We have previously proposed a method for retarding the ignition timing of an engine based on the amount of retardation when knocking occurs (Japanese Patent Application No. 58-5616). According to this method, since the ignition timing of the engine is not retarded except when knocking occurs, it is possible to prevent unnecessary reduction in output or deterioration of acceleration feeling.

[Problem that the invention seeks to solve]

However, in the method previously proposed by the applicant, when knocking occurs only once after setting the initial value as the retard amount, K retards the engine's ignition timing based on the retard amount at the time of knocking. Since the angle is controlled, it is possible to suppress the engine from knocking, but when knocking occurs again, the retardation amount of K is gradually attenuated. Even if the ignition timing of the engine is retarded, there is a fear that it may not be possible to sufficiently suppress engine knocking.

The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to sufficiently suppress the occurrence of knocking during sudden acceleration without causing unnecessary reduction in output or deterioration of acceleration feeling. An object of the present invention is to provide an ignition timing control device for an internal combustion engine that is capable of controlling the ignition timing of an internal combustion engine.

[Failure to solve the problem]

In order to achieve the above object, the present invention includes a throttle sensor that detects engine vibration, a throttle sensor that detects the opening of a throttle valve, and a throttle sensor that monitors the detection outputs of a knock sensor and a throttle sensor. When a sudden acceleration state of the engine is detected by the output, an initial value is set for the retard amount that is used to correct the ignition timing and gradually attenuates as time passes, and after setting this initial value, the knock sensor When the occurrence of knocking is detected by the detection output of K, the engine's ignition timing is retarded based on the amount of retardation at the time of knocking, and when further knocking occurs after this retardation control, K is The ignition timing control device for an internal combustion engine includes a control section that returns a retard amount to an initial value and retards the ignition timing of the engine based on this initial value.

[Effect]

The control unit that controls the ignition timing of the engine monitors the detection outputs of the knock sensor and throttle sensor, and when a sudden acceleration state of the engine is detected by the detection output of the throttle sensor, this is the amount of retardation for correcting the ignition timing. , and set an initial value for the amount of retardation that gradually attenuates over time, and after setting this initial value, when the occurrence of knocking is detected by the detection output of the knock sensor, the amount of retardation at the time of occurrence of knocking is set. When the engine's ignition timing is retarded and knocking occurs again after this retard control, K returns the retard amount at the time of knocking to its initial value, and retards the engine's ignition timing based on this initial value. Control the angle.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 1 shows the configuration of a preferred embodiment of the present invention. In FIG. 1, an air flow meter 2 as an intake air amount sensor is provided downstream of an air cleaner in an engine intake system. This air flow meter 2 has a rotatable vignetting convention plate (2A) and a conven motion plate (2A) which are rotatably installed in the damping chamber.
1 and a potentiometer 2B for detection, and is configured to detect the amount of intake air based on the output voltage of the potentiometer 2B.

On the downstream side of the air flow meter 2, an intake temperature riser 4 for detecting the temperature of intake air, a throttle valve 6, and a surge tank 8 are arranged. An intique manifold 10 is connected to this surge tank 8, and a fuel injection valve 12 is disposed in this intique manifold IOK.

The intique manifold 10 is connected to a combustion chamber 14A of the engine body 14, and the combustion chamber 14A of the engine is connected to an exhaust manifold 16. Further, a throttle sensor 18 is disposed in the intake system to detect the opening degree of the throttle valve 6, and a knock sensor is installed in the engine body 14 to detect vibrations of the engine caused by combustion, which is comprised of a spark plug 20, a microphone, etc. 22. A cooling water temperature sensor 24 is provided to detect the engine cooling water temperature.

The spark plug 20 is connected to a distributor 26 that supplies an ignition signal to the spark plugs of each cylinder, and an igniter 28 is connected to the distributor 26. This distributor 26 includes a cylinder discrimination sensor 30, which is fixed to the distributor housing and is composed of a pickup and a signal rotor fixed to the distributor housing. Engine rotation angle sensor 32
is provided. The cylinder discrimination sensor 30 is configured to output a KgcW8 discrimination signal, for example, every 720 degrees of crank angle, and the engine rotation angle sensor 32 is configured to output a crank angle reference position signal, for example, every 30 degrees of crank angle. Then, air flow meter 2, intake temperature sensor 4, throttle sensor 18, cooling water temperature sensor 24, knock sensor 2
2. Detection outputs from sensors that detect various operating states of the engine, such as the rotation angle sensor 32 and the air pressure discrimination sensor 30, are supplied to the control unit 34.

The control unit 34, as shown in FIG.
, ROM 38, CPU 40, clock 41, input/output ports 42, 44, output ports) 46, 48, etc., and each part has a path line 50 such as a data bus and a control path.
connected with.

The input/output boat 42 includes a multiplexer 54 having a buffer circuit and an analog/digital (A/D converter) 56.
Output signals of the air flow meter 2, cooling water temperature sensor 24, and intake air temperature sensor 4 are supplied via the air flow meter 2, the cooling water temperature sensor 24, and the intake air temperature sensor 4. Note that the multiplexer 54. The A/D converter 56 is controlled by a control signal output from the input/output port 42.

The input/output boat 44 is supplied with the detection output of the throttle sensor 18 as well as the detection outputs of the cylinder discrimination sensor 30 and the rotation angle sensor 32 via the waveform shaping circuit 64. Furthermore, the detection output of the knock sensor 18 is supplied to the input/output capo 44 via a band pass filter 60, a peak hold circuit 61, a channel switching circuit 66, and an A/D converter 68. A channel switching circuit 6 is connected to the bandpass filter 60 via an integrating circuit 63.
6 is connected, and one of the output signals of the peak hold circuit 61 and the output signal of the integration circuit 63 is selected by the channel switching circuit 66 and is configured to be supplied to the A/D converter 681C. ing. Further, the peak hold circuit 61 is supplied with a reset signal and a gate signal from the input/output port 44. When the engine vibrates due to knocking, this vibration is detected by the knock sensor 22 and a 6-8 KHz signal is supplied to the bandpass filter 60. band buzz filter 6
Since the knock sensor 22 is configured to attenuate the levels of low and high frequency signals, the output signal of the knock sensor 22 is supplied to a peak hold circuit 61 and an integration circuit 63 via a band pass filter 60.

For this reason, the peak value of the detection output of the knock sensor 22 is the same as that of the peak hold circuit 61, the channel switching circuit 66,
The signal is supplied to the input/output port 44 via the A/D converter 68. On the other hand, the integral value of the signal that has passed through the band pass filter 60 out of the detection output of the knock sensor 22 is transferred to the input/output port 44 via the channel switching circuit 66 and the A/D converter 68.
supplied to By comparing the peak value and the integral value of the detected pressure output of the knock sensor 22, the CPU 40 determines whether or not knocking has occurred.

Further, the output boat 46 is connected to the igniter 28 via a drive circuit 70, and the output boat 48 is connected to the drive circuit 72.
It is connected to the fuel injection valve 12 via. That is, the igniter 28 is supplied with a control signal for controlling the ignition timing, and the fuel injection valve 12 is supplied with a control signal for controlling the fuel injection time.

In addition, the ROM 38 stores in advance mag data of the basic ignition advance angle expressed by the engine speed and intake air t (or load), various data such as the basic fuel injection amount, and control programs, and the CPU 4 Q is configured to perform calculations for controlling the operating state of the engine based on the control program and the detection outputs of various sensors.

For example, based on the detection output of the air flow meter 2 and the rotation angle sensor 32, control data for the basic ignition advance angle and basic fuel injection amount are read from the ROM 3f3, and based on the detection outputs of the cooling water temperature sensor 24, the intake air temperature sensor 4, etc. A corrected retard amount and corrected fuel injection amount with respect to the basic ignition advance angle and basic fuel injection amount are calculated, and the operations of the igniter 28 and the fuel injection valve 12 are controlled based on the calculated values.

In addition, in this embodiment, since the sudden acceleration is determined based on the detection output of the throttle sensor 18,
The throttle sensor 18 is configured as follows.

That is, as shown in FIG.
has a substantially L-shaped rotating piece 80, and the base end of the rotating piece 800 is connected to the rotating shaft 6a of the throttle valve 6. Further, one end of a first contact 82 that extends along the tip of the rotating piece 80 and does not come into contact with the tip of the rotating piece 80 is fixed to the base end of the rotating piece 80. . Furthermore, a second contact 86 is fixed to the tip of the rotating piece 80, extending parallel to the first contact 82, with an insulating material 84 interposed therebetween. This second contact 86 is grounded. First contact 8
2. The second contact 86 rotates together with the rotating piece 80, and these rotating paths include a comb-shaped first electrode 88 and a second electrode 9.
0 is placed. The first electrode 88 is an electrode 881L,
88b, 88(!, 88d, and the second electrode 90 has electrodes 90a, 90b, 90c, 90
d, each electrode 88a-88d and electrode 90a-90d
are arranged alternately. and the first electrode 88, the second electrode 88,
One ends of the electrodes 90 are connected to a power source via resistors 92 and 941, respectively, and are also connected to the input/output port 44 of the control unit 340.

When the throttle valve 6 opens and rotates in the direction K (in the direction of the arrow in the figure), the rotating piece 80 rotates accordingly, and the throttle sensor 18 is in contact with the contacts 82 and 86. The tip of the contactor 82 rotates while alternately contacting the first electrode 88 and the second electrode 90. Since the contact 86 is grounded, the contact 82 is connected to the electrode 88 and the electrode 90.
When contacted alternately, the first electrode 88 and the second electrode 90 output a pulse signal as shown in FIG. Note that when the throttle valve 6 rotates in the closing direction, the contact 86 and the contact 82 rotate in a non-contact state, so a pulse signal is not output from the first electrode 88 and the second electrode 90. First, the output level of each electrode is maintained at a high level.

The output signals of these electrodes 88 and 90 are output from the input and output ports.
) 44. Then, when the throttle valve 6 is suddenly opened and the interval between the output pulses of the electrode 88 and the output pulse of the electrode 90 is less than 200 m8, the controller 34 determines that K is a sudden acceleration.

This embodiment has the above configuration, and then the wcS diagram to the seventh
The operation will be explained based on the flowchart shown in the figure. Note that the main routine processing of fuel injection control, air-fuel ratio control, and ignition timing control is the same as the conventional one, so a description thereof will be omitted.

First, as an interrupt routine at the time of rapid acceleration, as shown in FIG.
It is determined whether or not it is within mS (step 100). If the determination is NO in this step, the process moves to the next routine, and if the determination is YES, the process proceeds to step 102. That is, the throttle valve 6 is suddenly opened and the electrode 88.
When the generation interval of the output pulses 90 becomes less than 200 mS, the initial value of the retard amount is set for correcting the ignition timing, and the retard amount gradually attenuates as time passes (step 102). For example, processing is performed to set the initial value of the retard amount QACC as 10° CA. Once this initial value setting has been performed, the process moves to an interrupt routine that is performed every 4 mS, as shown in FIG.

In this routine, first, as shown in step 200, it is determined whether the retard amount QACC is greater than O. When the determination in this step is YES, K moves to step 202 and performs processing to attenuate the retard angle fQAcc by 0.1° CA. On the other hand, when the determination in step 200 is NO, K moves to step 204 and sets the retard amount QACC to 0.
Perform the process to set it to °CA. That is, in this routine, processing is performed to attenuate the retard amount QACC by 0.19 CA every 4 mS. Therefore, as shown in FIG. 8, when a sudden acceleration is detected at time t1, the retardation amount QAC
C is set as 10℃A, and 1 this retard amount QA
Processing is performed to gradually attenuate CC every 4 mS.

When sudden acceleration is detected in the interrupt routine shown in FIG. 5, the process shown in FIG. 7 is performed. That is, it is determined whether or not knocking has occurred based on the detection output of the knock sensor 22 (step 300). When it is detected in this step that knocking has occurred, the process moves to step 302 and it is determined whether the retard amount QACC is greater than O or not. When the determination in this step is YES, K moves to step 304, sets the count value C of the counter for determining the presence of knocking to CI+1, and moves to step 306. In step 306, it is determined whether the count value CI is greater than 2 and whether or not the squid is present.

If the count value CI is smaller than 2 in this step, that is, if the determination is No, the process moves to step 310. In step 310, as a process when knocking occurs for the first time after sudden acceleration (time 1+), the retardation amount at the time of knocking occurrence (time tx) is set as the retardation amount QACC1 &: retardation amount, and the delay in the basic ignition advance angle Qmsg 1 time t. Angular amount Q
Processing is performed to set ACC as the engine ignition timing Qig. For example, time t! The retardation amount Q Acc is 8°C
When A, K is the basic ignition advance angle Qll! l Perform retard control to set the engine ignition timing to the value obtained by subtracting 8°C A from E.

On the other hand, when the determination in step 306 is YES, that is, time t! When the knock occurs again (time ts)
In this step, processing is performed to return the retard amount QAcc to its initial value, that is, 10'CAK. The temperature Qnsx -10°C is treated as the engine ignition timing Qi2. That is, time t! When knocking occurs again after that, it is not sufficient to retard the ignition timing of the engine at time t, so at time t3, the retard amount QAC at time t2 is changed.
The ignition timing of the engine is controlled based on the retardation amount larger than C, that is, the initial value. Note that even if knocking occurs further after this, the process of returning the retard amount to the initial value is performed.

If the determination in step 302 is NO, the process moves to step 312, where the count value C1 is accepted, and the entire process of this routine is ended.

In this way, in this embodiment, the retardation amount is used to correct the ignition timing when a sudden acceleration state of the engine is detected.
In addition, an initial value is set for the amount of retardation that gradually attenuates as time passes, and when the occurrence of knocking is detected after setting this initial value, the ignition timing of the engine is retarded based on the amount of retardation at the time of occurrence of knocking. When knocking occurs again after this retard control, the retard amount at the time of knocking is returned to the initial value, and the engine's ignition timing is retarded based on this initial value. The occurrence of knocking can be sufficiently suppressed without causing a necessary decrease in output or deterioration of acceleration feeling, and damage to the engine due to the occurrence of knocking can be prevented.

In addition, in order to suppress knocking from occurring more than once during sudden acceleration, it is possible to set the initial value of K and the retard amount to a large value, but if this initial value is increased, there is a risk of misfire. . For this reason, it is desirable to retard the ignition timing of the engine every time knocking occurs, as in the above embodiment.

〔Effect of the invention〕

As explained above, according to the present invention, when a sudden acceleration state of the engine is detected, the initial value of the retard amount, which is the retard amount for correcting the ignition timing and which gradually attenuates as time passes, is set. When the occurrence of knocking is detected after setting this initial value, the engine's ignition timing is retarded based on the amount of retardation at the time of knocking, and if further knocking occurs after this retardation control, this The amount of retardation when knocking occurs is returned to its initial value, and the engine's ignition timing is retarded based on this initial value, resulting in an unnecessary drop in output and deterioration of acceleration feeling during sudden acceleration. An excellent effect can be obtained in that the occurrence of knocking can be sufficiently suppressed without any problems, and the occurrence of knocking can be sufficiently contributed to the protection of the engine.

[Brief explanation of drawings]

FIG. 1 is a flowchart for explaining the processing of the interrupt routine when the engine body to which the device according to the present invention is applied suddenly accelerates, and FIG. 6 shows the processing routine for attenuating the retardation amount during sudden acceleration. FIG. 7 is a flowchart for explaining the knock control processing routine, and FIG. 8 is a diagram showing the relationship between the output signal of the throttle sensor 18 and the amount of retardation. 6... Throttle valve, 12... Fuel injection valve, 14...
...Engine body, 22...Knock sensor, 26...
- Distributor, 34...control unit.

Claims (1)

[Claims] (1) A knock sensor detects engine vibration, a throttle sensor detects the opening of the throttle valve, and the detection outputs of the knock sensor and throttle sensor are monitored, and a sudden acceleration state of the engine is detected by the detection output of the throttle sensor. When this happens, an initial value is set for the retard amount that is used to correct the ignition timing and gradually attenuates as time passes, and after this initial value is set, the detection output of the knock sensor indicates that knocking has occurred. is detected, the engine's ignition timing is retarded based on the amount of retardation at the time of knocking, and if knocking occurs again after this retardation control, the retardation amount at the time of knocking is set to the initial value. 1. An ignition timing control device for an internal combustion engine, comprising: a control section that returns the initial value and retards the ignition timing of the engine based on the initial value.