JPH03275981A - Controller for ignition timing of engine - Google Patents

Abstract

PURPOSE:To surely start an engine even if a reference signal is not input because of abnormality of a reference position sensor by providing a reference position judging means for judging as the true reference position a reference position temporarily set by a main ignition signal outputting means, in the event that even when restrained by an auxiliary ignition setting means engine output is not lowered. CONSTITUTION:When abnormality of a reference position sensor is detected, the timing of a reference position temporarily set by a main ignition signal outputting means is temporarily set as an auxiliary reference position by an auxiliary ignition signal outputting means and an auxiliary ignition signal is output to an ignition cylinder decided according to the temporarily set auxiliary reference position. Further an auxiliary ignition signal is set by an auxiliary ignition restraining means in such a manner as restraining engine output in proportion to operating conditions of an engine, and the signal is output. The reference position temporarily set by the main ignition signal outputting means is judged as the true reference position by a reference position judging means in the event that engine output is not lowered with the auxiliary ignition signal set by the auxiliary ignition restraining means.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an engine ignition timing control device that controls the engine ignition timing based on a signal from a rotation sensor (reference position sensor, crank angle sensor). In particular, it relates to bank up when the reference position sensor is abnormal.

[Conventional technology]

Conventionally, the ignition timing of an engine has been determined by a reference position sensor that is attached to the camshaft and outputs a pulse (reference signal) once every 1 revolution of the camshaft (two revolutions of the engine), and a reference position sensor that is attached to the crankshaft that outputs a pulse (reference signal) once per revolution of the camshaft (two revolutions of the engine). angle (e.g. 30
This is carried out in response to each signal from a crank angle sensor that outputs a pulse (crank angle signal) at every interval (A) (for example, Japanese Patent Laid-Open No. 139976/1983).

[Problem to be solved by the invention]

In the engine ignition timing control device as described above, if the reference signal is no longer output due to an abnormality in the reference position sensor or the like, it becomes impossible to determine the reference position at the time of starting. Therefore, since the ignition cylinder that outputs the ignition signal cannot be determined, there is a problem in that the engine cannot be started.

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide an ignition timing control device for an engine that is capable of starting and detecting a reference position even when a reference signal is not output. It is about providing.

[Means to solve the problem]

As shown in FIG. 1, the present invention includes a reference position sensor that detects the rotational position of a shaft that rotates once every two revolutions of the engine, and outputs a reference signal for detecting the reference position every two revolutions of the engine. , a sub-reference position sensor that detects the rotational position of the crankshaft of the engine and outputs a signal for detecting the reference position and a signal for detecting a sub-reference position shifted by 360 crank angles from the reference position; , an output sensor that detects the output of the engine, an abnormality detection means that detects an abnormality of the reference position sensor, and when an abnormality of the reference position I sensor is detected, two revolutions of the engine are detected from the sub reference position sensor. Main ignition signal output means temporarily sets one of the signals output twice as a reference position, and outputs a main ignition signal to an ignition cylinder determined based on the temporarily set reference position; When an abnormality in the I sensor is detected, the timing of the reference position temporarily set by the main ignition signal output means is temporarily set as the sub-reference position, and the ignition cylinder is set to the ignition cylinder determined based on the temporarily set sub-reference position. auxiliary ignition signal output means for outputting a auxiliary ignition signal; auxiliary ignition suppressing means for suppressing the output of the engine according to the operating state of the engine; and the output of the engine is reduced even when suppressed by the auxiliary ignition suppressing means. The gist of the present invention is to provide an ignition timing control device for an engine, comprising a reference position determining means for determining a reference position provisionally set by the main ignition signal output means as the true reference position if the main ignition signal output means does not.

[Effect]

With the above configuration, the abnormality detection means detects an abnormality in the reference position sensor for detecting the reference position of the engine.

When an abnormality in the reference position sensor is detected, the main ignition signal output means temporarily sets one of the signals output from the sub reference position sensor twice per two revolutions of the engine as the reference position,
A main ignition signal is output to the ignition cylinder determined based on this temporarily set reference position. Further, when an abnormality in the reference position sensor is detected, the sub-ignition signal output means temporarily sets the timing of the reference position temporarily set by the main ignition signal output means as the sub-reference position as described above. A sub-ignition signal is output to the ignition cylinder determined based on the sub-reference position. Further, a sub-ignition signal is set and outputted by the sub-ignition suppressing means to suppress the output of the engine according to the operating state of the engine. Then, the reference position determining means determines the reference position provisionally set by the main ignition signal outputting means as the true reference position if the engine output is not reduced by the auxiliary ignition signal set by the auxiliary ignition suppressing means.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a V-type six-cylinder four-stroke engine (hereinafter simply referred to as engine) will be described below with reference to the drawings.

FIG. 2 is a schematic configuration diagram of this embodiment, and FIG. 12 is a time chart of this embodiment.

In FIG. 2, l is provided on a camshaft (not shown) that rotates once every two revolutions of the engine, and is located at a reference position (for example, the ignition top dead center of the 6th cylinder in this embodiment) as shown in FIG. 12(b). This is a reference position sensor that generates pulses C and M as reference signals once every 1 revolution of the camshaft, that is, 2 revolutions (720" CA) of the crankshaft. 2 is synchronized with the rotation of the engine. As shown in Fig. 12(c), the timing is synchronized with the reference position twice for every two revolutions (720" CA) of the crankshaft, and the timing is deviated from the reference position by 360" CA. This is a sub-reference position sensor that generates a pulse GS twice at a timing synchronized with the sub-reference position.

3 is provided on the crankshaft, as shown in FIG. 12(a), at a predetermined angle (for example, 30
) This is a crank angle sensor as a rotation angle sensor that generates a pulse NE every time.

In addition, 4 is a water temperature sensor that detects the engine cooling water temperature;
5 is an intake air amount sensor that detects the engine intake air amount (engine load).

Reference numeral 10 denotes an engine control unit f (ECU), into which sensor signals from the various sensors 1 to 5 described above are input, and based on these sensor signals, ignition timing, fuel injection amount, etc. are set, and the set ignition timing is controlled. , outputs a control signal corresponding to the fuel injection amount, etc. to an actuator (igniter 20, injector, not shown, etc.). In addition, as is well known, ECUlo outputs the output waveforms from the reference position sensor 1, sub-reference position sensor 2, and crank angle sensor 3 as shown in Fig. 12 (a).
) to (c), a waveform shaping circuit 11 whose bottom shape is a pulse wave, an analog-to-digital converter ( ADC) 12, a central processing unit (CPU) 13 that performs various calculations and sets ignition timing, fuel injection amount, etc., a read-only memory (R, OM) 14, Writable/readable random memory that temporarily stores calculation data, etc.
The access memory (RAM) 15, the bus 16 interconnecting these, and the ignition signal IGT output from the CPU 13 are distributed according to signals 31 to S3 in FIG.
) to (i) Ignition signal IC1 corresponding to each cylinder as shown in
-1G6, a multiplexer (MPX) 17.

The igniter 20 drives the ignition coil 30 disposed in each cylinder in response to the ignition signal IC1-106 corresponding to each cylinder output from the ECUIO, and supplies high voltage to the spark plug 40.

Then, this igniter 20 receives the above-mentioned ignition signals IG1~
Drive time 1N21 and power transistor 2 for driving the power transistor 22 of the cylinder corresponding to IG6
A resistor 23 for detecting the current ITR flowing through 2 and this resistor 2
3, and a constant current circuit 24 that suppresses the current ITR to below a permissible value in accordance with the current ITR detected by the circuit 3.

The ignition timing control method of this embodiment will be described below using flowcharts shown in FIGS. 3 to 11.

FIG. 3 shows a routine for ignition timing control. This routine is started by an interrupt every predetermined crank angle (for example, in this embodiment, every time a pulse NE is inputted to the ECUIO from the crank angle sensor 3, that is, every 3o'' CA).

When the pulse NE is input and this routine is started, first, in step 100, the time TN of the crank angle 120''CA is determined.
Calculate EW. This time TNEW is used for deceleration determination, rotation speed detection, etc., as will be described later.

In the following step 200, abnormality detection of the reference position sensor 1 is performed. Specifically, it is detected based on whether or not pulse GM is input between 720"CA. If pulse GM is not input manually between 720"CA, it is determined that the reference position sensor 1 is abnormal, and steps 1000 and thereafter are performed. If the pulse GM is manually applied during 720''CA, it is determined that the reference position sensor 1 is normal, and the routine proceeds to the normal processing routine starting from step 300.

The normal processing routine will be described below.

In step 300, normal counter CCRNK processing is performed. Here, this counter CCRNK detects the crank angle from the reference position.

Therefore, this counter CCRNK is counted up every time this routine is started, that is, every 30° CA.
It is set to 1 at the timing when pulse GM and pulse GS are input simultaneously, that is, at the crank angle corresponding to the reference position, and the timing when only pulse GS is manually input, that is, at the sub-reference position shifted by 360"CA from the reference position, it is set to 13. is set to

The normal counter CCRNK processing (step 300) will be explained in detail based on the flowchart shown in FIG. First, in step 310, it is detected whether the pulse GM was manually applied at the current control timing. here,
If the pulse GM is manually input, the crank angle at the current control timing corresponds to the reference position, so the process proceeds to step 320, where the counter CCRNK is set to 1 (CCRNK←1) as described above. The process further advances to step 330, where a flag XO indicating that the setting of the reference position has been completed.
Set K (XOK 4-1) L and proceed to step 400.

If the pulse GM is not input in step 310, the process proceeds to step 340, and it is detected whether the pulse GS is input at the current control timing. Here, if the pulse GS is input, the crank angle at the current control timing corresponds to the sub-reference position, so the process advances to step 350, and the counter CCRN is input as described above.
Set K to 13 (CCRNK←13).

On the other hand, if the pulse GS is not manually applied in step 340, the process proceeds to step 360, and it is detected whether the counter CCRNK is O or not. Here, counter CCRNK is 0
In this case, since the pulse CM has not yet been input at the time of starting, the ignition cylinder has not been determined, so ignition is not performed and this routine ends. Also, counter CCRN
If K is not O, the process proceeds to step 370, and it is detected whether the counter CCRNK is 24 or not. Here, if the counter CCRNK is not 24, the process advances to step 380;
Count up the counter CCRNK (C
CRNK 4-CCRNK+1) and proceeds to step 400.

If the counter CCRNK is set to 24 in step 370, that is, the counter CCRNK is not set to 1 even though the crankshaft has made two revolutions (720″CA), the process advances to step 390.Then, in step 390, the counter CCRNK is set to 1. Forcibly set to 1 (CCRNK←1
) and proceeds to step 400, where the normal counter CCRN
The K process (step 300) ends.

Then, returning to FIG. 3, in step 400,
As disclosed in Japanese Patent No. 139976, etc., ignition timing control is performed in accordance with the rotational speed and the like.

In the following step 500, other processing initiated by the angle interrupt is performed, and this routine ends.

On the other hand, if the pulse CM is not manually applied during 720'' CA in step 200, it is determined that the reference position sensor l is abnormal, and the process proceeds to the abnormality processing routine from step 1000.In step 1000, the flag XOK is set. It is detected whether the cylinder discrimination has been completed based on the state of the flag XOK.Here, if the flag XOK is in the reset state (XOK=O), that is, if the cylinder discrimination has not been completed, the process advances to step 1100, and the cylinder discrimination processing in the event of an abnormality is performed. conduct.

Hereinafter, the cylinder discrimination process (step 1100) at the time of abnormality will be explained in detail based on the flowchart shown in FIG. First, in step 1102, it is determined whether or not it is the timing to operate a counter CINV used for determining acceleration/deceleration, which will be described later. Here, the operation timing of the counter CINV is when the conditions that the current control timing is the top dead center and the sub-ignition is canting (XCUT=1), which will be described later, are satisfied. Here, if it is not the above operation timing, the process advances to step 1106. On the other hand, if it is the operation timing, the process advances to step 1104 and the counter CINV is operated.

Based on the flowchart shown in FIG.
The operation of V (step 1104) will be explained. First, in step 11042, it is detected whether or not the vehicle is in a deceleration state. Specifically, the detection is performed by comparing the time TNEW calculated in step 100 in FIG. 3 at the current control timing with the time TOLD calculated at the previous control timing. If the time TNEW is greater than the time TOLD, that is, the deceleration state is in progress, the process proceeds to step 11044, and the counter CINV is counted down (CrNV←CINV-1).
l, Proceed to step 11048. Also, the time TNEW
is equal to or larger than the time TOLD, that is, it is not in a deceleration state, the process advances to step 11046, and the counter (I
Count up NV (CINV 4-CTNV+1)
L. Proceed to step 11048. And step 11
At 048, the time TOL is set in preparation for the next control timing.
Assign the time TNEW to D and proceed to the next step.

Returning to FIG. 5, in step 1106 it is detected whether or not the pulse C3 was manually applied at the current control timing. If the pulse GS is not manually applied, the process proceeds to step 1108, and it is detected whether or not a temporary setting of a reference position, which will be described later, has been performed at the time of startup with the reference position sensor l in an abnormal state.

Specifically, as shown in FIG. 12(j), the detection is performed using a flag FGS that is set when the reference position is tentatively set. Here, the flag FGS is in reset state B (FGS=0)
In other words, if the reference position has not been provisionally set, the ignition cylinder cannot be specified and the routine ends without igniting. Further, if the flag FGS is set (FGS=1) in step 110B, that is, the reference position has already been provisionally set, the process advances to step 111O, and the counter C
Count up CRNK (CCRNK 4-CCRN
K+1)L, proceed to step 1134.

If the pulse GS is manually applied in step 1106, the process advances to step 1112, and the state of the flag FGS is detected. Here, the flag FGS is in a reset state (FGS=
O), that is, if the reference position has not been provisionally set,
Proceeding to step 1114, the crank angle in the current control tie is temporarily set as a reference position. First, in step 1114, flags FC and S are set as cents (FGS=1).
do. Then, in step 1116, the counter CCRNK
Set to 1 (CCRNK 4-1)L, step 111
Proceed to 8 and set flag XG1 to cents (XGI=1). Here, the flag XGI is inverted every time a pulse GS is input, as will be described later. Therefore, depending on the state of this flag XGl, it can be determined whether the timing at which the pulse GS is input is at the reference position or the sub-reference position. Then, the process advances to step 1134.

On the other hand, flag FGS is set in step 1112! 1
(FGS=1), that is, if the reference position has been temporarily set, the process advances to step 112o.

In step 1120, flag X indicates whether or not the sub-ignition is being cut.
Detected by the state of CUT. Here, the flag XCtJ
If T is in the reset state (XCUT=O), that is, if the auxiliary ignition is not being cut, the process advances to step 1126, and the flag XG1 is inverted.

Further, if the flag XCUT is in the cent state (XCUT=1), that is, if the sub-ignition is in cant, step 11
The process proceeds to step 22, where cylinder discrimination at the time of abnormality is performed. Step 112
In step 2, it is detected from the value of the counter CINV whether or not the output of the engine has decreased due to the sub-ignition being cut, resulting in a deceleration state. If the value of the counter CrNV is negative, that is, it is in a deceleration state, it cannot be determined whether the currently provisionally set reference position is correct or incorrect, so step 1128 is performed without inverting the flag XG1 (step 1126).
Proceed to. Therefore, the temporarily set reference position will be shifted by 360'CA from the currently temporarily set reference position.

Also, if the value of the counter CINV is positive in step 1122,
That is, if it is not in a deceleration state, it is determined that the currently provisionally set reference position is correct, and the flag is set to XOK in step 1124.
Set (XOK←1).

Then, in step 1126, the flag XGl is inverted.

Next, in step 1128, the state of flag XGI is detected. Here, the flag XGI is in the sent state (XG1=1)
That is, if the current control timing is the reference position, the process proceeds to step 1130, sets the counter CCR, NK to 1 (CCRNK=1)L, and proceeds to step 1134. On the other hand, if the flag XG1 is in the reset state (X(:, 1=O), that is, the current control timing is the sub-reference position, the process advances to step 1132, and the counter CCRNK is set to 13 (C
CRNK=1)L, proceed to step 1134. In step 1134, the flag XCUT and the counter CINV
Configure settings.

The flag XCUT and counter CINV setting process (step 1134) will be described in detail based on the flowchart of FIG.

First, in step 11342, the counter CINV is reset (CINV←0). Next, in step 11344, it is detected whether the cylinder discrimination condition at the time of abnormality is satisfied.

Here, the cylinder discrimination condition in the case of an abnormality is, for example, in this embodiment, the rotation speed is equal to or higher than a predetermined value (for example, in this embodiment, 500 rpm, which is the start determination rotation speed). Here, if the cylinder discrimination condition at the time of abnormality is not satisfied, step 113
At step 45, the flag XCUT is reset to perform sub-ignition (XCUT-0). In addition, if the cylinder discrimination condition at the time of abnormality is satisfied, the flag
Set CUT and cancel sub-ignition (XCUT←0)
. Then, cylinder discrimination is performed based on the output state of the engine when sub-ignition is stopped. Next, in step 11348, time TNEW is substituted for time TOLD in preparation for the next control.

This completes the flag XCUT and counter CINV setting process (step 1134).

Returning to FIG. 3, the process advances to step 1200 to perform ignition processing in the event of an abnormality. The ignition process (step 1200) in the event of an abnormality will be explained in detail based on the flowchart shown in FIG.

First, in step 1210, it is detected whether the current control timing is 30'' CA before top dead center.
If it is 0''CA, the process advances to step 1220 and outputs an energization start signal to start energizing the igniter 20 (
ignition signal).

Also, if it is not 30″ CA before top dead center, step 123
0, and detects whether or not the current control tie is at top dead center. Here, if it is the top dead center, the process proceeds to step 1240, and a energization stop signal is outputted to stop energizing the igniter 20 (lowering the ignition signal), that is, ignition is performed at this timing.

On the other hand, if it is not the top dead center, this process ends.

Through the above processing, main ignition is performed at the top dead center of the ignition cylinder.

Returning to FIG. 3, the process proceeds to step 500 and other processing is performed as described above.

Also, the flag XOK is set to 11 in step 1ooo.
i (XOK=1), that is, when the cylinder discrimination has been completed, the process advances to step 1300 and performs counter CCRNK processing at the time of abnormality. The counter CCRNK processing (step 1300) at the time of abnormality will be explained in detail based on the flowchart shown in FIG.

First, in step 1310, it is detected whether or not the pulse GS was manually applied at the current control timing. here,
If the pulse GS is not operated manually, step 1320
Then, it is detected whether the value of the counter CCRNK is 24 or not. Here, if the value of the counter CCRNK is 24, the process advances to step 1350. On the other hand, if the value of the counter CCRNK is not 24, the process advances to step 1330, and the counter CCR,NK is counted up (CCR,N
K←CCRNK+1).

Further, if the pulse GS is manually applied in step 131O, the process advances to step 1340, and the flag FG1 is inverted.

In the following step 1350, the state of flag X01 is detected. Here, flag XGl is set B (XC; 1=1)
In this case, since the current control timing is the reference position, the process advances to step 1360, and the counter CCRNK is set to 1 (CCRNK←1). On the other hand, if the flag XG1 is in the reset state (XG1=O), since the current control timing is the sub-reference position, the process advances to step 1370 and the counter CCRNK is set to 13 (CCRNK
4-13). This completes the counter CCRNK processing at the time of abnormality.

Returning to FIG. 3, the process proceeds to step 400, where the ignition process is performed as described above. This completes the ignition timing control routine.

Further, the flag XOK is reset in the engine control main routine. The flag XOK reset process will be explained based on the flowchart shown in FIG.

In the main routine, various processes for engine control are performed (steps 50 and 70).

Then, in step 60, the rotation speed is detected based on the time TNEW, and in the subsequent step 62, the rotation speed as a reset condition for the flag XOK is set to a predetermined rotation speed (for example, in this embodiment, 5
00 rpm) or less. Here, if the number of rotations is equal to or higher than the predetermined number of rotations, the process proceeds to step 70 and other processing is performed. If the rotation speed is below the predetermined rotation speed, the process proceeds to step 64 and resets the flag XOK (XOK←0
).

Then, the process advances to step 70 to perform other processing.

This completes the flag XOK reset processing of the main routine.

Next, the auxiliary ignition signal output processing will be explained based on the flowchart shown in FIG. This routine is activated by interruption in synchronization with the above-mentioned main ignition signal and the below-mentioned sub-ignition signal.

First, in step 2000, it is detected whether the current interrupt is caused by the rising edge or falling edge of the main ignition signal or the sub ignition signal. Here, in the case of an interruption due to the rise of the ignition signal, this routine is ended. In addition, in the case of an interrupt due to a falling edge, step 201
Go to 0.

In step 2010, the state of flag FMON is detected. Here, the flag FMON is a flag FMON indicating whether the current interrupt is caused by the main ignition signal or by the sub-ignition signal, as shown in FIG. 12(k).

When the flag F M ON is in the reset state (FMO
N=O), that is, if the interruption is due to the sub-ignition signal, the process proceeds to step 2030. Further, if the flag FMON is in the cent state (FMON=1), that is, if the interrupt is caused by the main ignition signal, the process proceeds to step 2020, and it is detected by the flag XCUT whether or not the sub ignition is being cut. Here, if the sub-ignition is being cut (XCUT=1), the process advances to step 2030. At step 2030, the counter C
The main ignition distribution signal indicating the cylinder to which the next ignition signal will be output according to the value of CRNK outputs signals S1 to S3 to the MPX 17, and the process proceeds to step 2040. And step 204
Set flag FMON at 0 (FMON 4-1)L,
This routine ends.

Further, if the sub-ignition is not canting in step 2020 (flag XCUT=O), the process proceeds to step 2050.

In step 2050, signals S1 to S3 are output to the MPX 17 for sub-ignition distribution indicating the cylinder to which the next ignition signal will be output in accordance with the value of the counter CCRNK, and the process proceeds to step 2060. At step 2060, reset the flag FMON (
FMON←0), and the process proceeds to step 2070, where a sub-ignition signal is output to the igniter 20. Here, the sub-ignition signal is a pulse of a predetermined time (for example, 5 m5ec in this embodiment). This completes this routine.

According to this embodiment, as shown in FIG. 12, if the pulse GM is not manually operated due to an abnormality in the reference position sensor 3 at the time of starting, the sub reference position sensor 2 outputs a signal twice for every two rotations of the engine. Temporarily set one of them as the reference position. A main ignition signal is output to the ignition cylinder determined according to this temporarily set reference position. Furthermore, this timing is provisionally set as the sub-reference position. A sub-ignition signal is output to the ignition cylinder determined according to this temporarily set sub-reference position. Therefore, even if the reference position temporarily set as described above is actually the sub-reference position, the sub-ignition signal will also be applied to the ignition cylinder determined from the sub-reference position that is shifted by 360'CA from the temporarily set reference position. Output. Therefore, starting is possible even when the reference position sensor 3 is abnormal.

Furthermore, after the start is completed, the auxiliary ignition signal is cut.

The reference position is determined based on the change in rotational speed at that time. Therefore, after starting, the normal reference position can be determined.

Furthermore, in the above embodiment, in the igniter 20, the power transistors 22 provided for each cylinder are driven using a common constant current circuit 24, that is, it is not possible to drive two or more power transistors at the same time. Therefore, the sub ignition signal is output after the main ignition signal is output. However, regarding a device that includes a plurality of constant current circuits 24 and can drive two or more power transistors at the same time, Japanese Patent Laid-Open No. 62-7847
As disclosed in Japanese Patent No. 6, the main ignition signal and the sub-ignition signal may be output simultaneously. In addition, although the sub-ignition signal is cut in order to determine the reference position, as disclosed in the above-mentioned Japanese Patent Laid-Open No. 62-78476, the sub-ignition signal is retarded, that is, the output of the engine is suppressed. You can also do this.

Furthermore, in the embodiment described above, the crank angle sensor and the sub-reference position sensor 2 are provided separately; however,
As disclosed in Japanese Patent Application Laid-open No. 56-7013,
The two sensors 2 and 3 may be shared.

Further, in the embodiment described above, a change in the rotational speed is used as a method for detecting the output state of the engine, but the engine torque may be detected using a torque sensor or the like.

〔Effect of the invention〕

As explained in detail above, according to the present invention, if the reference signal is not input due to an abnormality in the reference position sensor etc. at the time of starting, one of the signals output from the sub-reference position sensor twice per two rotations of the engine is output. One side is temporarily set as a reference position, and a main ignition signal is output to the ignition cylinder determined by this temporarily set reference position. Furthermore, an auxiliary ignition signal is output to the ignition cylinder determined when the temporarily set reference position is set as the auxiliary reference position. Additionally, the engine output is suppressed depending on the engine condition. When the engine output is suppressed in this manner, if the engine output does not decrease, it is determined that the temporarily set reference position is correct.

Therefore, even if the reference signal is not input due to an abnormality in the reference position sensor, etc., it is possible to start the engine reliably.
Moreover, there is an excellent effect that the reference position can also be determined.

3... Rotation angle sensor, 10... ECU, 20...
Igniter, 30...Ignition coil, 40...Spark plug.

Claims (1)

[Scope of Claims] A reference position sensor that detects the rotational position of a shaft that rotates once every two revolutions of the engine and outputs a reference signal for detecting a reference position every two revolutions of the engine; and a crank of the engine. A signal for detecting the rotational position of the shaft and detecting the reference position and 360 from the reference position.
a sub-reference position sensor that outputs a signal for detecting a sub-reference position with a crank angle deviation; an output sensor that detects the output of the engine; an abnormality detection means that detects an abnormality of the reference position sensor; When an abnormality in the position sensor is detected, one of the signals output from the sub-reference position sensor twice per two rotations of the engine is temporarily set as a reference position, and the position sensor is set based on the temporarily set reference position. a main ignition signal output means for outputting a main ignition signal to a determined ignition cylinder; and when an abnormality in the reference position sensor is detected, the timing of the reference position provisionally set by the main ignition signal output means is set as a sub reference position. an auxiliary ignition signal output means that is temporarily set and outputs an auxiliary ignition signal to an ignition cylinder determined based on the temporarily set auxiliary reference position; and an auxiliary ignition that suppresses the output of the engine according to the operating state of the engine. a suppressing means; and a reference position determining means for determining a reference position provisionally set by the main ignition signal output means as a true reference position if the output of the engine does not decrease even if suppressed by the sub-ignition setting means. An engine ignition timing control device comprising: