JPH0711264B2 - Ignition signal control method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition signal control system which is preferably implemented for ignition control of an internal combustion engine used as an engine of an automobile or the like.

2. Description of the Related Art FIG. 6 is a block diagram showing a configuration of a conventional ignition signal control circuit in an internal combustion engine. At the time of starting the internal combustion engine, the sensor for detecting the rotation angle of the internal combustion engine is likely to malfunction due to the rush current to the starter motor and the mechanical vibration accompanying the start of rotation of the starter motor. Generally, the control of the ignition signal is performed according to the output of the sensor, and in order to eliminate the influence of the malfunction of the sensor, the control circuit of such an ignition signal includes a masking signal generation circuit 1 and a NOR circuit 2,
Consists of 3 and 4. The masking signal generation circuit 1 is supplied with the starter signal Sta, and the masking signal generation circuit 1 is supplied with the starter signal Sta for a certain period of time.
A masking signal Sms for masking the ignition signal is output. The masking signal Sms is given to the NOR circuit 4.

The NOR circuit 2 has a starter signal Sta and a soft ignition signal S1.
Is given, and the output signal is given to the NOR circuit 4. The soft ignition signal S1 is the optimum ignition timing control signal obtained by the calculation of the computer. The NOR circuit 3 is supplied with an inverted signal of the starter signal Sta and the hard ignition signal S2, and the output signal is supplied to the NOR circuit 4. The hard ignition signal S2 is a fixed ignition timing control signal used in place of the soft ignition signal S1 when the internal combustion engine is started or the computer is abnormal. NOR circuit 4 uses masking signal Sms
The output signals of the NOR circuits 2 and 3 are calculated and the ignition signal S3 is output.

FIG. 7 is a timing chart showing the operating state of the control circuit when the internal combustion engine is started. When the starter signal Sta is set to high level at time t1 as shown in FIG. 7 (1), the masking signal generation circuit 1 outputs high level from time t1 to period T1 as shown in FIG. 7 (2). The masking signal Sms which is said to be output. In the period T1, N
Since one input signal of the OR circuit 4 is at high level, the ignition signal S3 is always at low level regardless of the other two input signals.

After the period T1 has elapsed, the masking signal Sms is at low level, but the starter signal Sta is at high level. Therefore, since one input of the NOR circuit 2 is at high level, NOR
The output signal of the circuit 2 is always low level. NO at this time
Since one input of the R circuit 3 is always at a low level, the NOR circuit 3 outputs an inverted signal of the hard ignition signal S2 and NO
It is given to the R circuit 4. At this time, since the masking signal Sms and the output of the NOR circuit 2 are always at the low level, the inverted signal of the hard ignition signal S2 is inverted again by the NOR circuit 4, and the hard ignition signal S2 shown in FIG. , As the ignition signal S3 as shown in FIG. 7 (5). Therefore, at the start of the internal combustion engine, a good ignition signal control state can be obtained.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the above-described conventional technology, reading of the starter signal Sta is performed unconditionally, and when the starter signal Sta is detected even when the internal combustion engine is in a normal operating state, at start-up. There is a problem that the ignition signal is controlled in the same manner as in.
FIG. 8 is a timing chart for explaining the output of the ignition signal when the starter signal Sta is detected while the internal combustion engine is in the normal operating state. It is assumed that the starter signal Sta is input at time t2 as shown in FIG. 8 (1). Before time t2, the starter signal Sta is at the low level, so both the masking signal Sms and the output of the NOR circuit 3 are at the low level. Therefore, the soft ignition signal S1 shown in FIG. 8 (3) is output as the ignition signal S3 as shown in FIG. 8 (5).

From time t2 until period T2 elapses, masking signal Sm
Since s is set to the high level, the ignition signal S3 is not output during the period T2. Since the rotation speed of the internal combustion engine in the normal operating state is higher than the rotation speed at the time of starting, the number of timings at which the ignition signal S3 is generated in the period T2 is higher than that at the time of starting. However, due to the masking signal Sms, the ignition signal S3 is not output in the period T2, so that a temporary torque shortage state occurs.

Further, after the lapse of the period T2, the starter signal Sta is at the high level, so the hard ignition signal S2 shown in FIG. 8 (4) is output as the ignition signal S3, and the internal combustion engine is out of the optimum ignition control state. It comes off and the torque is insufficient.

In addition, recent internal combustion engines are excellent in quietness, and if the ignition key is operated without noticing that the internal combustion engine is in the idling state when the vehicle is stopped in the idling state, the starter signal Sta is entered,
The ignition signal S3 is switched to the hard ignition signal S2 as described above.

Generally, a normally operating microcomputer outputs an ignition signal and the like and monitors whether or not ignition is performed in response to the output. If not, the microcomputer determines that the igniter or the like has failed and issues an error signal. On the other hand, at start-up, a large current is supplied to the starter motor, which causes the battery voltage to drop and the microcomputer not to generate an error signal, but after start-up the starter motor has only a small current. Since the microcomputer does not flow and the voltage of the battery does not drop, the microcomputer is operating normally.When the ignition signal S3 switches to the hard ignition signal S2 in such a state, the computer determines that the internal combustion engine has entered an abnormal state. However, there is a problem that an error signal is generated.

It is an object of the present invention to provide an ignition signal control system in which the starter signal is not read when the internal combustion engine is in a normal operating state.

Means for Solving the Problems The present invention provides a starter signal of a first control signal obtained by calculation by a calculation device and a second control signal generated in a predetermined manner by a fixed signal generation means. In the ignition signal control method in which only the second control signal is used as the ignition signal for a predetermined period from the time of switching from the non-active state to the active state, a determining means for determining a normal operating state of the arithmetic unit, A first detecting means for detecting that the internal combustion engine whose ignition is controlled by an ignition signal has switched from a starting state to a normal operating state; and a first detecting means for detecting an operating state in which the internal combustion engine exceeds a predetermined rotational speed. When the determination means, the first detection means, and the second detection means detect corresponding operating states, the starter signal is output based on these outputs. It is filed when the One I switched a control method of an ignition signal to the use of the first control signal as an ignition signal.

Operation According to the present invention, of the first control signal obtained by calculation by the calculation device and the second control signal generated by the fixed signal generating means in a predetermined manner, the starter signal is inactive. In the ignition signal control method in which only the second control signal is used as the ignition signal for a predetermined period from the time of switching from the active state to the active state, the determining means determines the normal operating state of the arithmetic unit, and the first detecting means. Detects that the internal combustion engine whose ignition is controlled by the ignition signal is switched from the starting state to the normal operating state, and the second control means sets the operating state in which the internal combustion engine exceeds a predetermined rotational speed. To detect.

When the determination means, the first detection means, and the second detection means detect the corresponding operating states, that is, when the internal combustion engine is in the normal operating state, when the starter signal is switched, Also uses the first control signal as the ignition signal.

Embodiment FIG. 1 is a block diagram for explaining the basic structure of the present invention. The starter signal STA is supplied to the computer 12 and the AND circuit 13 after the voltage level is adjusted by the input buffer 11. Internal combustion engine speed signal R
Is given to the computer 12. Computer 12
The watchdog signal WDC is supplied to the WDT reset circuit 16 and the start judgment output S11 is supplied to the NAND circuit 14. The WDT reset circuit 16 determines whether or not the computer 12 is operating normally based on the watchdog signal WDC, and if it is operating normally, supplies a high-level determination signal S16 to the NAND circuit 14.

The NAND circuit 14 includes a start determination output signal S11 and a determination signal S16.
A logical operation is performed on the output signal S12 and the output signal S12 is given to the AND circuit 13. The output signal S12 is at a low level when the computer 12 is operating normally and the internal combustion engine is in a normal operating state. Therefore, in the above state, AND
The output signal S13 of the circuit 13 is always low level, and the starter signal STA is not output.

FIG. 2 is a flow chart illustrating a determination method for determining the operating state of the internal combustion engine. At step n1, the period X of the internal combustion engine speed signal R is calculated. Step n2
Then, determine whether the start determination output S11 is high level,
If it is low level, that is, the internal combustion engine is starting, the process proceeds to step n3. At step n3, it is determined whether the cycle X is smaller than the first reference cycle A. For the first reference period A, for example, the period of the rotation speed signal when the rotation speed of the internal combustion engine is 500 rpm is selected.

In step n3, when the cycle X is larger than the first reference cycle A, that is, when the rotation speed of the internal combustion engine is lower than 500 rpm, the process proceeds to step n4 to set the start determination output S11 to the low level. In step n3, the cycle X is the first reference cycle A
When it is smaller, that is, when the rotation speed of the internal combustion engine is higher than 500 rpm, the routine proceeds to step n6, where the start determination output S11 is made high level.

In step n2, if the start determination output S11 is at high level, that is, if the internal combustion engine is in the normal operating state, the process proceeds to step n5. In step n5, it is determined whether the cycle X is larger than the second reference cycle B. As the second reference period B, for example, the period of the rotation speed signal when the internal combustion engine is set to 400 rpm is selected. That is, a value larger than the first reference cycle A is selected for the second reference cycle B.

At step n5, if the cycle X is larger than the second reference cycle B, that is, if the rotation speed of the internal combustion engine is lower than 400 rpm, the routine proceeds to step n4, where the start determination output S11 is made low level. In step n5, the cycle X is the second reference cycle B
If it is smaller, that is, if the rotation speed of the internal combustion engine is higher than 400 rpm, the routine proceeds to step n6, where the start determination output S11 is made high level.

Therefore, when determining whether the internal combustion engine has exited the starting state, the reference speed of the internal combustion engine is, for example, 50
When 0 rpm is selected and it is determined whether the internal combustion engine is maintaining the specified rotation speed in the normal operating state,
For example, 400 rpm is selected as the reference speed of the internal combustion engine.

FIG. 3 is a block diagram showing the configuration of the ignition control circuit of one embodiment of the present invention. Since this embodiment uses the configuration of FIG. 1 described above, the same reference numerals are given to the corresponding configurations.

The starter signal STA is supplied to the computer 12 and the AND circuit 13 after the voltage is adjusted by the input buffer 11. A reference position signal G and an angle signal N are given to a computer 12 and a fixed ignition signal generating circuit 20 from a crank angle sensor provided in a crank of the internal combustion engine. In addition to the starter signal STA, the reference position signal G and the angle signal N, the computer 12 is supplied with a rotation speed signal R of the internal combustion engine.

The computer 12 determines the operating state based on the starter signal STA and the rotational speed signal R, and is set to a low level when the internal combustion engine is in a starting state and a high level when the internal combustion engine is in a normal operating state. Output S11 to NAND circuit 14
And a soft ignition signal S12 obtained by calculation based on the reference position signal G and the angle signal N is given to the NOR circuit 15. The computer 12 also supplies the watchdog signal WDC to the WDT reset circuit 16.

The WDT reset circuit 16 determines whether or not the computer 12 is operating normally based on the watchdog signal WDC, and outputs the determination signal S16, which is high level during normal operation, to the NAND circuit 14
Give to. The NAND circuit 14 performs a logical operation on the determination signal S16 and the start determination output S11, and gives the output signal S12 to the AND circuit 13. The AND circuit 13 performs a logical operation on the input buffer output and the output signal S12, and gives the output signal S13 to the masking signal generation circuit 17 and the NOR circuits 15 and 18.
The fixed ignition signal producing circuit 20 produces a hard ignition signal HAR which is brought to a high level at regular intervals based on the reference position signal G and the angle signal N, and gives it to the NOR circuit 18.

The masking signal generation circuit 17 outputs the output signal S13 of the AND circuit 13.
A masking signal MS that is kept at a high level for a certain period from the rising edge of is generated, and the masking signal MS is given to the NOR circuit 19. The output signal S13 of the AND circuit 13 and the soft ignition signal SOF from the computer 12 are input to the NOR circuit 15, and the output is given to the NOR circuit 19. NOR circuit 18 has AND circuit 13
The inverted signal of the output signal S13 and the hard ignition signal HAR from the fixed ignition signal generation circuit 20 are input, and the output is the NOR circuit 19
Given to. The output of the NOR circuit 19 is used as the ignition signal S14.

FIG. 4 is a timing chart showing an operating state of the ignition signal control circuit at the time of starting the internal combustion engine. It is assumed that the ignition key is operated to start the internal combustion engine and the starter signal STA is set to the high level at time t5 as shown in FIG. 4 (1). The internal combustion engine is driven by the starter motor, and from the crank angle sensor, it is shown in Fig. 4 (2).
The reference position signal G shown in FIG. 4 and the angle signal N shown in FIG. 4 (3) are given to the computer 12 and the fixed ignition signal generating circuit 20. Based on the reference position signal G and the angle signal N, the computer 12 gives a soft ignition signal SOF shown in FIG. 4 (4) to the NOR circuit 15 that has created it, and further based on the internal combustion engine speed signal R, the internal combustion engine. Determines whether or not it has left the starting state, and supplies the starting judgment output S11 shown in FIG. 4 (7) to the NAND circuit 14. Fixed ignition signal generation circuit 2
0 creates the hard ignition signal HAR shown in Fig. 4 (5),
Give to NOR circuit 18. The NAND circuit 14 has a WDT reset circuit.
A determination signal S16 (see (6) in FIG. 4) from 16 is given.

Since the internal combustion engine has not left the starting state until time t6,
The start determination output S11 is set to low level, and the output S12 of the NAND circuit 14 is set to high level as shown in FIG. 4 (8). Therefore, the output S13 from the AND circuit 13 becomes equal to the starter signal STA as shown in FIG. 4 (9).

The output S13 is given to the masking signal generation circuit 17 and the NOR circuits 15 and 18. The masking signal creation circuit 17
As shown in FIG. 4 (10), a masking signal MS that is kept at high level during the period T5 from the time t5 to the time t7 when the output S13 rises is created and given to the NOR circuit 19. Therefore, during the period T5, the ignition signal S14 is not output because one input of the NOR circuit 19 is at the high level.

From time t7 to time t8, the output S13 is at high level, so the output of the NOR circuit 15 is at low level, and the masking signal MS is also at low level. Therefore, the NOR circuit 19 outputs an inverted signal of the output of the NOR circuit 18. NOR circuit
Since the inverted signal (low level signal) of the output S13 is given to 18, the NOR circuit 18 outputs an inverted signal of the hard ignition signal HAR, and the inverted signal is inverted again by the NOR circuit 19. Therefore, as shown in FIG. 4 (11), the hard ignition signal HAR shown in FIG. 4 (5) is output as the ignition signal S14 from time t7 to time t8.

After the time t8, the output S13 is at the low level, so the output of the NOR circuit 19 to which the inverted signal of the output S13 is applied is at the low level, and the masking signal MS is also at the low level. Therefore, the NOR circuit 19 outputs an inverted signal of the output of the NOR circuit 15. Since one input of the NOR circuit 15 is at the low level, the NOR circuit 15 outputs an inverted signal of the soft ignition signal SOF, and the inverted signal is inverted again by the NOR circuit 19. Therefore, after time t8, Fig. 4 (11)
As shown in, the soft ignition signal SOF is output as the ignition signal S14.

FIG. 5 is a timing chart showing the operating state of the ignition signal control circuit during normal operation of the internal combustion engine. The internal combustion engine is in a normal operating state, and the crank angle sensor outputs the reference position signal G shown in FIG.
The angle signal N shown in FIG. 2 is given to the computer 12 and the fixed ignition signal generating circuit 20. Based on the reference position signal G and the angle signal N, the computer 12 produces the soft ignition signal SOF shown in FIG. 5 (4), and the fixed ignition signal producing circuit 20 produces the hard ignition signal SOF shown in FIG. 5 (5). Create the ignition signal HAR.

As shown in FIG. 5 (1), it is assumed that the starter signal STA is at the high level during the period from time t11 to time t12. During this period, the computer 12 is operating normally and the internal combustion engine is in a normal operating state. Therefore, the determination signal S16 shown in FIG. 5 (6) and the start determination output S11 shown in FIG. 5 (7) are both High level. Therefore N
The output signal S12 of the AND circuit 14 becomes the low level shown in FIG. 5 (8), and the output signal S13 of the AND circuit 13 is also the low level. That is, since the starter signal STA is not read, the masking signal MS is not generated as shown in FIG. 5 (10), and the ignition signal S14 is not released. Furthermore, since the output signal S13 is always low level,
As shown in 1), the soft ignition signal SOF is the ignition signal S14.
Is always output as.

As described above, according to the present embodiment, during normal operation of the internal combustion engine, the starter signal STA is not read even if the ignition key is mistakenly operated. Therefore, even if the ignition key is mistakenly operated while the car is running, insufficient torque does not occur, and if the ignition key is mistakenly operated in the idling state, the computer 12 detects an abnormal condition. Then, the output of the error signal is prevented.

As described above, according to the present invention, when the internal combustion engine is in the normal operation state and the arithmetic device is in the normal operation state,
Even when the starter signal is switched from the inactive state to the active state, the first control signal obtained by calculation by the calculation device is used as the ignition signal. As a result, the ignition control of the internal combustion engine is always maintained in the optimum control state, and the torque shortage of the internal combustion engine is prevented.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram for explaining the basic configuration of the present invention, FIG. 2 is a flow chart for explaining a determination method for determining an operating state of an internal combustion engine, and FIG. FIG. 4 is a block diagram showing the configuration of an ignition signal control circuit according to an embodiment of the present invention.
FIG. 5 is a timing chart showing the operating state of the ignition signal control circuit when the internal combustion engine is started, FIG. 5 is a timing chart showing the operating state of the ignition signal control circuit during normal operation of the internal combustion engine, and FIG. 6 is conventional ignition. FIG. 7 is a block diagram showing the configuration of the signal control circuit, FIG. 7 is a timing chart showing a conventional ignition signal control state at the time of starting the internal combustion engine, and FIG. 8 is a conventional ignition signal control state at the time of normal operation of the internal combustion engine. Is a timing chart showing. 12 …… Computer, 16 …… WDT reset circuit, 20 ……
Fixed ignition signal generation circuit, SOF …… First control signal, HAR ……
Second control signal, STA ... Starter signal

Claims (1)

[Claims] 1. A starter signal is activated from an inactive state of a starter signal of a first control signal obtained by calculation by a calculation device and a second control signal generated by a fixed signal generating means in a predetermined manner. In the ignition signal control method in which only the second control signal is used as the ignition signal for a predetermined period from the time of switching to the state, the determination means for determining the normal operation state of the arithmetic unit and the ignition signal are used for ignition. It includes a first detecting means for detecting that the controlled internal combustion engine is switched from a starting state to a normal operating state, and a second detecting means for detecting an operating state in which the internal combustion engine exceeds a predetermined rotational speed. When the determination means, the first detection means, and the second detection means detect the corresponding operating states, when the starter signal is switched based on these outputs, Also uses the above-mentioned first control signal as the ignition signal.