JP2003113734A - Fault diagnosis control device for rotational angle sensor of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a normal rotational angle sensor from being misdiagnosed as having an anomaly upon an anomaly in a cranking signal (starter signal) in a fault diagnosis control device for a rotational frequency sensor of an internal combustion engine. SOLUTION: A controlling means comprises a fault diagnosing part for receiving an input of a starter signal from a starter signal detecting means and diagnosing the rotational angle sensor as having a fault if at least one condition is met out of the condition that a variation in fuel injection quantity calculated by a fuel injection variation calculating part is larger than a set value, the condition that a variation in battery voltage calculated by a battery voltage variation calculating part is larger than a set value, the condition that a variation in intake air calculated by an intake air variation calculating part is larger than a set value, and the condition that a variation in intake pressure calculated by an intake pressure variation calculating part is larger than a set value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a failure diagnosis control device for a rotation angle sensor of an internal combustion engine, and more particularly to a failure diagnosis control device for a rotation angle sensor of an internal combustion engine which prevents erroneous diagnosis of the rotation angle sensor.

[0002]

2. Description of the Related Art In an internal combustion engine mounted on a vehicle or the like, for example, various sensors such as a rotation angle sensor for detecting a rotation angle of a rotary shaft are provided, and various signals from these various sensors cause the air-fuel ratio to reach a target value. The fuel injection amount is controlled so that the air-fuel ratio becomes appropriate, the combustibility is improved by improving the air-fuel ratio, the exhaust gas purification efficiency by the catalyst is improved, and the exhaust gas harmful components are reduced.

In the internal combustion engine, various types of rotation angle sensors, such as a cam angle sensor for detecting the rotation angle of a cam shaft as a rotation shaft and a crank angle sensor for detecting the rotation angle of a crank shaft as a rotation shaft, are used. A sensor is provided. However, if any of these sensors fails, an erroneous detection result will result and the air-fuel ratio cannot be maintained properly.

Therefore, for example, in the failure diagnosis of the cam angle sensor or the crank angle sensor, as shown in FIGS. 16 and 17, the condition that the ignition switch (Ig.SW) is turned on and the ignition signal is turned on. And (shown by time T1 in FIG. 16), and thereafter, the cranking switch (or starter switch (ST SW)) is turned on and the cranking signal (or starter signal) is turned on (see FIG. 16). At time T2), this cranking signal (or starter signal) is turned on (shown at time T2 in FIG. 16) and is a constant time x1 second (shown between time T2 and time T3 in FIG. 16). ) By the cam signal (CM
When all the conditions, that is, the condition that the CNT) (or the crank signal (CRCNT)) is not detected, it is diagnosed that the cam angle sensor or the crank angle sensor is abnormal.

A method of diagnosing such a rotation angle sensor is disclosed, for example, in Japanese Patent Laid-Open No. 2000-82240. The one described in this publication measures the cranking time from the change in the battery voltage, and when the cranking time is long and the stroke judgment of a predetermined cylinder is not completed, the crank angle sensor is diagnosed as a failure and the starter Even with an internal combustion engine that does not have a switch, it is possible to prevent erroneous diagnosis of the crank angle sensor.

[0006]

However, in the conventional method of diagnosing the cam angle sensor or the crank angle sensor which is the rotation angle sensor, as shown in FIG. 18, for example, a cranking switch (or a starter switch (ST・ S
W)) is faulty and the cranking signal (or starter signal) is short-circuited to the high voltage (High) side from the beginning, the ignition switch (Ig · SW) is turned on (time in FIG. 18). After that, the operation in which the cranking signal (or the starter signal) is turned on does not occur, so that the cam signal (CMCNT) (or the crank signal (CRCNT)) is not input to the control means. When x1 seconds, which is a constant time from when the ignition signal is turned on (shown by T4 in FIG. 18), has elapsed (shown by T5 in FIG. 18), the abnormality flag of the cam angle sensor (or the crank angle sensor) is set to be normal. The cam angle sensor (or crank angle sensor) has been misdiagnosed as abnormal, and the cam angle sensor (or crank angle sensor) has failed in the market. The information Tsu, normal cam angle sensor (or a crank angle sensor) there is inconvenience that are replaced unnecessarily.

[0007]

Therefore, in order to eliminate the above-mentioned inconvenience, the present invention provides a rotation angle sensor for detecting the rotation angle of the rotation shaft of an internal combustion engine and outputting a signal, and the ignition signal is turned on. After that, in the failure diagnosis control device for the rotation angle sensor of the internal combustion engine for diagnosing whether or not the rotation angle sensor has a failure depending on the presence or absence of an output signal from the rotation angle sensor, a starter signal detection means for detecting a starter signal is provided, A fuel injection change amount calculation unit that can calculate the change amount of the fuel injection amount for a fixed time, a battery voltage change amount calculation unit that can calculate the change amount of the battery voltage for a fixed time, and a change amount of the intake air for the fixed time The intake air change amount calculating unit and the intake pressure change amount calculating unit capable of calculating the change amount of the intake pressure for a fixed time are provided, and the starter signal detecting unit outputs the change amount. A condition that the change amount of the fuel injection amount calculated by the fuel injection change amount calculation unit is larger than a set value and the change amount of the battery voltage calculated by the battery voltage change amount calculation unit is more than the set value. A large condition, a condition in which the intake air change amount calculated by the intake air change amount calculation unit is larger than a set value, and a condition in which the intake pressure change amount calculated by the intake pressure change amount calculation unit is larger than a set value. It is characterized in that a control means provided with a failure diagnosis section for diagnosing the failure of the rotation angle sensor when at least one condition is satisfied is provided.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, when a cranking signal (starter signal) is abnormal, a normal rotation angle sensor is erroneously diagnosed as abnormal when at least one of the above conditions is satisfied. When there is an error due to poor rotation angle sensor installation, it is possible to distinguish between the poor installation and the failure due to damage to the rotation angle sensor itself, short-circuiting of wiring, damage to parts of the rotation angle sensor, etc. Therefore, by identifying the faulty part when such a defect occurs, the repair time and the work time for finding the abnormal part can be shortened, and the rotation angle sensor which is normal but is erroneously diagnosed as abnormal Since it is not necessary to replace the parts, it is possible to reduce the cost of parts and work and shorten the work time.

[0009]

Embodiments of the present invention will be described in detail and specifically with reference to the drawings. 1 to 15 show an embodiment of the present invention. In FIG. 15, 2 is an internal combustion engine mounted on a vehicle (not shown), 4 is an intake passage, and 6 is an exhaust passage.

The internal combustion engine 2 is constructed by arranging a first cylinder bank 8 on one side and a second cylinder bank 10 on the other side in a V shape.

In the intake passage 4, an air cleaner 12, an intake temperature sensor 14 for detecting the temperature of intake air, and an air flow sensor 16 for detecting the intake air amount are sequentially installed from the upstream side.
And a throttle valve 18 are provided. Downstream of the intake passage 4, two first and second branched intake passages 4-
It is branched into 1 and 4-2. First branch intake passage 4-1
Is connected to a combustion chamber (not shown) on the first cylinder bank 8 side, and the second branch intake passage 4-2 is connected to a combustion chamber on the second cylinder bank 10 side.

A throttle opening sensor 20 for detecting the throttle opening of the throttle valve 18 is provided in the intake passage 4. Further, the intake passage 4 is provided with a bypass passage 22 that bypasses the throttle valve 18. An idle control valve (ISC valve) 24 for adjusting the air flow rate is provided in the middle of the bypass passage 22.

The exhaust passage 6 has a first upstream side and a second upstream side.
It branches into branch exhaust passages 6-1 and 6-2. The first branch exhaust passage 6-1 is connected to the combustion chamber on the first cylinder bank 8 side, and the second branch exhaust passage 6-2 is connected to the combustion chamber on the second cylinder bank 10 side.

A first catalytic converter 26-1 is provided in the middle of the first branch exhaust passage 6-1 and a second catalytic converter 26-2 is provided in the middle of the second branch exhaust passage 6-2. A first front-side O2 sensor 28- that detects the oxygen concentration in the exhaust gas of the first branch exhaust passage 6-1 is provided in the upstream side of the first catalytic converter 26-1 in the middle of the first branch exhaust passage 6-1. 1 is provided. In addition, a first rear O2 sensor 30-1 is provided at a location downstream of the first catalytic converter 26-1 in the middle of the first branch exhaust passage 6-1.

At a portion upstream of the second catalytic converter 26-2 in the middle of the second branch exhaust passage 6-2, a second front side O2 for detecting the oxygen concentration in the exhaust of the second branch exhaust passage 6-2. A sensor 28-2 is provided. Further, a second rear O2 sensor 30-2 is provided at a position downstream of the second catalytic converter 26-2 in the middle of the second branch exhaust passage 6-2.

First and second rear O2 sensors 30-1, 3
The first and second branch exhaust passages 6-1 and 6-2 are merged in a portion downstream of 0-2, and the three-way catalytic converter 32 is provided in the exhaust passage 6 downstream of the merged portion. It is arranged.

The internal combustion engine 2 is provided with a fuel injection valve 34 facing the combustion chamber. This fuel injection valve 34
Are connected to a fuel tank 38 via a fuel supply passage 36. The fuel in the fuel tank 38 is sent under pressure by the fuel pump 40, the dust contained in the fuel filter 42 is removed, and the fuel supply passage 36 is used to remove the fuel.
4 is supplied.

A fuel pressure adjusting section 44 for adjusting the pressure of the fuel is provided in the middle of the fuel supply passage 36 so as to communicate therewith. The fuel pressure adjusting unit 44 adjusts the fuel pressure to a constant value by the intake pipe pressure, which is the intake pressure introduced from the pressure guiding passage 46 communicating with the intake passage 4, and the excess fuel from the fuel return passage 48 to the fuel tank. It returns to 38.
A fuel level sensor 50 and a pressure sensor 52 are arranged in the fuel tank 38.

Inside the fuel tank 38, there is a passage 54 for evaporated fuel.
Through the intake passage 4 downstream of the throttle valve 18. A canister 56 is provided in the middle of the fuel vapor passage 54.

The internal combustion engine 2 is provided with EGR control means 58. The EGR control means 58 adjusts the EGR amount of the exhaust gas recirculated from the exhaust system to the intake system.
A valve 60 is provided. This EGR valve 60
Is the second branch exhaust passage 6-2 on the upstream side of the second front side O2 sensor 28-2 of the exhaust system and the first and second intake systems.
E that communicates with the merging portion of the branch intake passages 4-1 and 4-2
It is provided in the GR passage 62 and is electronically controlled to
The amount is adjusted.

A PCV valve 64 is provided in the second cylinder bank 10 of the internal combustion engine 2.

The intake air temperature sensor 14, the mass air flow sensor 16, the throttle opening sensor 20, the idle control valve 24, the first front side O2 sensor 28-1, and the first
A rear O2 sensor 30-1, a second front O2 sensor 28-2, a second rear O2 sensor 30-2, a fuel injection valve 34, a fuel pump 40, a pressure sensor 52,
The EGR valve 60 communicates with a control means (ECM) 66.

Further, the control means 66 includes the internal combustion engine 2
Cam angle sensor 68 as a rotation angle sensor that detects the rotation angle of the cam shaft as one of the rotation shafts and outputs a cam signal
An intake pressure sensor 70 for detecting an intake pipe pressure which is an intake pressure, an ignition coil assembly 72, a water temperature sensor 74 for detecting a cooling water temperature of the internal combustion engine 2, and a crank serving as the other rotating shaft of the internal combustion engine 2. A crank angle sensor 76 as a rotation angle sensor that detects the rotation angle of the shaft and outputs a crank signal, an indicator lamp 78, a connection terminal 80, and a power steering pressure switch 82.
, Heater blower fan switch 84, cruise control module 86, vehicle speed sensor 88, combination meter 90, A / D condenser fan relay 92, A / C controller 94, data link connector 96, ABS Controller module 98
, A main relay 100, an ignition switch 102 that outputs an ignition signal by turning on the engine key, a P / N position switch 104, a battery 106, and a starter that is turned on when the starter operates to output a starter signal. Starter switch 108 as signal detection means, O / D off lamp 110, power lamp 112, lighting switch 114, stop lamp switch 116, and O / D cut switch 1
18, a power / normal change switch 120,
4WD / LOW switch 122, transmission range switch 124, and first solenoid valve 126
, Second solenoid valve 128, TCC solenoid valve 130, A / T input speed sensor 13
2, the A / T output speed sensor 134, the cranking switch 136 that is turned on when the internal combustion engine 2 cranks, and the engine speed sensor 138 that detects the engine speed.

Further, the control means 66 includes a fuel injection change amount calculation unit 66A capable of calculating the change amount (ΔTp) of the fuel injection amount (Tp) for a fixed time (x1), and the fixed time (x
1) The battery voltage change amount calculation unit 66B capable of calculating the change amount (ΔVb) of the battery voltage (Vb) and the intake air capable of calculating the change amount (ΔQa) of the intake air (Qa) for a certain time (x1). The change amount calculation unit 66C and a fixed time (x
The intake pressure change amount calculation unit 66D capable of calculating the change amount (ΔPin) of the intake pipe pressure (negative pressure) (Pin) which is the intake pressure of 1) is provided, and the starter switch 10 is provided.
Input the starter signal from 8, and as shown in FIGS.
The condition that the change amount (ΔTp) of the fuel injection amount calculated by the fuel injection change amount calculation unit 66A is larger than the set value (TPM) and the change amount (ΔVb) of the battery voltage calculated by the battery voltage change amount calculation unit 66B are set. Value larger than the value (VBM) and a condition where the intake air change amount (ΔQa) calculated by the intake air change amount calculation unit 66C is larger than the set value (QAM) and the intake pressure change amount calculation unit 66D calculates A failure diagnosis unit 66E for diagnosing a failure of the cam angle sensor 68 and the crank angle sensor 76 when at least one of the condition that the pressure change amount (ΔPin) is larger than the set value (PINM) is satisfied is provided. Further, a timer 66F is provided. The predetermined time (x1) is the same as in the conventional case shown in FIG.
This is the same as the time shown in 6 and 18.

That is, in this embodiment, specifically, in order to increase the reliability of erroneous diagnosis of the cam angle sensor 68 and the crank angle sensor 76, which are rotation angle sensors, as shown in FIG. Inputting the starter signal, the fuel injection change amount calculation unit 66A calculates the change amount (ΔTp) of the fuel injection amount larger than the set value (TPM), and the battery voltage change amount calculation unit 66B calculates the battery voltage. Change amount (ΔVb) is larger than the set value (VBM), and the intake air change amount (ΔQa) calculated by the intake air change amount calculating section 66C is larger than the set value (QAM). The change amount (ΔPin) of the intake pipe pressure calculated by the change amount calculation unit 66D is the set value (PIN
When all the conditions that are larger than M) are satisfied, the cam angle sensor 68 and the crank angle sensor 76 are diagnosed as a failure. Further, as shown in FIGS. 8 and 15, the crank angle sensor 76 comprises a crank gear 76A and a sensor body 76B, and the output waveform input from the sensor body 76B to the control means 66 is as shown in FIG. Sensor body 76B
This is a proposal for the case where the waveform shaping section 76B-1 in FIG. Also, two cam signals 1 and 2 from the cam angle sensor 68 and one from the crank angle sensor 76
When one crank signal is being output, and each of these signals is a pulse signal whose waveform has been shaped as shown in FIG. 16 of the related art, as shown in FIG. : Cam signal 2: Crank signal is 2: 3:
This is the case when it is designed as 12.

Next, the operation of this embodiment will be described based on the flowcharts of FIGS.

When the internal combustion engine 2 is started and the power is turned on with the engine key, the program starts (step 20).
2) After that, it is determined whether or not the ignition switch 102 is on (step 204). If the ignition switch 102 is off and step 204 is no, this determination is continued, while the ignition switch 102 is on. If step 204 is YES, it is determined whether or not the starter switch 108 is on (step 206),
The starter switch 108 is off, and step 206 is N
If it is O, the process returns to step 204, while the starter switch 108 is on and the starter is activated, and step 2
If 06 is YES, the internal combustion engine 2 is started.

At this time, if the starter operates, fuel injection is performed, the battery voltage is reduced by the load of the starter, the intake air amount is increased, and the intake pipe pressure is changed.

Conventionally, as shown in FIGS. 16 and 17, in the failure diagnosis of the cam angle sensor and the crank angle sensor, the condition that the ignition switch is turned on and the cranking switch (starter switch) is turned on. By satisfying all of the conditions and the condition that the cam signal is not counted for x1 second which is a constant time from when the cranking switch (starter switch) is turned on, the cam angle sensor (or the crank angle sensor) is I was diagnosed with an abnormality.

However, as shown in FIG. 18, when the cranking signal (starter signal) is short-circuited to the high voltage (High) side, the failure diagnosis condition for the cam angle sensor (or crank angle sensor) is satisfied. , Despite the abnormal cranking signal (or starter signal),
There is a problem that the cam angle sensor (or the crank angle sensor) is erroneously diagnosed as abnormal.

Therefore, in this embodiment, when the internal combustion engine 2 is started, when the starter actually operates, the change amount of the fuel injection amount (ΔT) is changed as the change amount of the engine load.
p), the amount of change in the battery voltage (ΔVb), the amount of change in the intake air (ΔQa), and the amount of change in the intake pipe pressure (ΔPin) are detected, and these changes are compared with their respective set values. The individual variations are used alone or in combination, and are added to the diagnostic condition for the failure of the cam angle sensor 68 or the crank angle sensor 76.

That is, as shown in FIG. 1, step 206
After YES, it is determined whether or not the change amount (ΔTp) of the fuel injection amount is larger than the set value (TPM) (step 2
08), ΔTp <TPM, and this step 208 is NO.
In case of, return to step 204, while ΔTp> TP
If YES in step 208, it is determined whether or not the amount of change in battery voltage (ΔVB) is larger than the set value (VBM) (step 210), and ΔVB <VB
If M and this step 210 is NO, step 2
04, while ΔVB> VBM, this step 2
If 10 is YES, the amount of change in intake air (ΔQa)
Is larger than the set value (QAM) (step 212), and if ΔQa <QAM, then this step 212
If NO is returned to step 204, while ΔQa
> QAM and if step 212 is YES, it is determined whether or not the amount of change in the intake pipe pressure (ΔPin) is larger than the set value (PINM) (step 214), and ΔPi
If n <PIN and this step 214 is NO,
Return to step 204.

On the other hand, if ΔPin> PINM and this step 214 is YES, the number of pulses of the cam signal 1 for a fixed time x1 second is recorded in CMCNT1, and the cam signal voltage of the cam signal 1 for x1 second is CM1V. Record the number of pulses of the cam signal 2 for a fixed time x 1 second on CMCNT2
, And record the cam signal voltage of cam signal 2 for x1 second in CM
Record at 2V (step 216).

Further, the number of pulses of the crank signal is CRCN.
Record T and the crank signal voltage in CRV (step 218).

Then, it is judged whether or not a predetermined time x1 second has elapsed (step 220). If this step 220 is NO, the process returns to step 216.

If YES in step 220 after the lapse of a certain time x1 second, it is determined whether or not the number of pulses of the cam signal 1 is one pulse or more with CMCNT1> 1 (step 222). .

If the number of pulses of the cam signal 1 is not even one pulse, CMCNT1 <1, and this step 2
In the case where 22 is NO, in order to determine whether the cam signal 1 is disconnected or has a high voltage (High) short circuit, first, as shown in part A of FIG. It is determined whether or not (CM1V) is larger than a cam signal determination voltage (CMMIN) that is a set value (step 224), and CM1V> CMMIN, and this step 22
When 4 is YES, the high voltage of the cam signal 1 (High)
Abnormal short circuit (step 226), CM1V <C
If the step 224 is NO in MMIN, it is determined that the low voltage (Low) short of the cam signal 1 is abnormal (step 228).

When the step 222 is YES, the CMCN is
In the case of T1> 1, since the pulse of the cam signal 2 is input as shown in the portion B of FIG.
It is determined whether or not the number of pulses is 1 or more with CMCNT2> 1 (step 230).

If the number of pulses of the cam signal 2 is not 1 pulse and CMCNT2 <1, it is determined in step 230
If NO, then in order to determine whether the cam signal 2 is disconnected or has a high voltage (High) short circuit, first, the cam signal determination of the cam signal voltage (CM2V) of the cam signal 2 is the set value. It is determined whether the voltage is higher than the voltage (CMMIN) (step 232), and CM2V> CMMIN.
If this step 232 is YES, the high voltage (H
It is determined that a short circuit is abnormal (step 234). On the other hand, when CM2V <CMMIN, this step 232 is N
In the case of O, it is determined as an abnormality of low voltage (Low) short circuit (step 236).

If the result at step 230 in FIG. 3 is YES, the crank angle sensor 76, as shown at C in FIG.
The crank signal (CRCNT) of is diagnosed.

First, it is determined whether or not the number of pulses of the crank signal (CRCNT) is 1 or more with CRCNT1> 1 (step 238).

If the number of pulses of the crank signal is not 1 pulse and CRCNT <1, the step 238 is executed.
If NO, the crank signal voltage (CRV) of the crank signal is first determined from the crank signal determination voltage (CRVMIN), which is the set value, in order to determine whether the crank signal is disconnected or has a high voltage short circuit. Is also large (step 240), CRV> CRVMIN
If this step 240 is YES, the high voltage (H
It is determined that a short circuit is abnormal (step 242). On the other hand, when CRV <CRVMIN, this step 240 becomes N
In the case of O, it is determined as an abnormality of low voltage (Low) short circuit (step 244).

Steps 226 and 228 of FIG. 2, FIG.
234 and 236 of FIG. 4 and step 24 of FIG.
After the abnormality diagnosis of 2.244, as shown in part D of FIG. 5, a lamp or the like is turned on to notify the driver of the abnormality (step 246) and the program ends (step 248).

On the other hand, YES in step 238 of FIG.
In the case of, it is diagnosed whether or not the cam signals 1 and 2 and the pulse number of the crank signal CMCNT1: CMCNT2: CRCNT are normal.

That is, as shown in part E of FIG. 6, CMCN
Taking in each pulse number of T1, CMCNT2, and CRCNT (step 250), CMCNT1, CMCNT2,
It is determined whether the CRCNT is abnormal (step 252),
If CMCNT1: CMCNT2: CRCNT are normal, pulses are input at a ratio of 2: 3: 12.
When the pulse ratios match and this step 252 is NO, it is regarded as normal (step 254) and the program is ended (step 256).

On the other hand, CMCNT1: CMCNT2: CR
CNT is not in the ratio of 2: 3: 12, but CMCNT1: C
MCNT2: CRCNT is abnormal, this step 252
If is YES, it is determined whether the pulse numbers of CMCNT1 and CMCNT2 are abnormal (step 258).

That is, CMCNT1: CMCNT2 is 2: 3, the pulse ratio is normal, and step 25
When 8 is NO, the cam angle sensor 76 is normal and the pulse of the crank angle sensor 76 is abnormal (step 26).
0).

On the other hand, if step 258 is YES, if the cam angle sensor 68 is abnormal and the pulse ratio is not normal, then it is determined whether the pulse ratios of CMCNT1: CRCNT and 2:12 are correct ( Step 262), C
If the pulse ratios of MCNT1: CRCNT and 2:12 are correct and this step 262 is NO, the pulse of the cam signal 2 is abnormal (step 264).

On the other hand, if YES in step 262, the pulse ratios of CMCNT1: CRCNT and 2:12 are not correct, and the pulse ratios of CMCNT2 and CRCNT are compared (step 266), and CMCNT2 and CRC are compared.
The pulse ratio with NT is correct, and this step 266 is N
When it is O, the pulse of the cam signal 1 is abnormal (step 268).

When the step 266 is YES, the CMCN is
When the pulse ratios of T2 and CRCNT are incorrect, all the signal ratios are different and the cam angle sensor 6
The hardware part of No. 8 is abnormal (step 270).

Steps 260, 264, 268, 2
After the diagnosis of 70, a lamp or the like is turned on to inform the driver of the abnormality (step 272), and the program ends (step 256).

If both the cam angle sensor 68 and the crank angle sensor 76 are abnormal, the cam angle sensor 68 is first repaired normally by the diagnosis flow, and then the crank angle sensor 68 is repaired. Since the abnormality of the angle sensor 76 is diagnosed, it will be repaired normally.

As a result, when the cranking signal (starter signal) is abnormal and at least one of the above-mentioned conditions is satisfied, the normal cam angle sensor 68 and the crank angle sensor 76 are erroneously determined to be abnormal. The diagnosis is not made, and the cam angle sensor 68 and the crank angle sensor 76 are not detected.
At the time of abnormality due to improper mounting of the cam angle sensor 68, the cam angle sensor 68 or the crank angle sensor 76 itself is broken, the wiring is short-circuited short-circuited, or the cam angle sensor 68 or the crank angle sensor 76 is damaged, or the like. Therefore, by identifying the faulty part when such a failure occurs, the repair time and the work time for finding the abnormal part can be shortened, and the fault is erroneously diagnosed as abnormal. Since the cam angle sensor 68 and the crank angle sensor 76 are not unnecessarily replaced, the cost of parts and work can be reduced, and the work time can be shortened.

In this embodiment, the case where the sensor body 76B of the crank angle sensor 76 is provided with the waveform shaping section 76B-1 has been described. However, when the crank angle sensor is not provided with the waveform shaping section, , As shown in FIGS.

That is, as shown in FIG. 9, in the magnetic crank angle sensor 176, the sensor body 176B does not have a waveform shaping section, and the output waveform thereof is shown in FIG. If the sensor body has a waveform shaping part, the sensor body becomes large and the mounting space is limited, and the mounting layout becomes large, so if the mounting space is narrow,
A crank angle sensor 176 having no waveform shaping section as shown in FIG. 9 is used. In such a case, as shown in FIG. 15, the control means 66 is provided with a waveform shaping section 66G for shaping the waveform of the signal from the sensor body 176B.

In this case, the output waveform of the crank angle sensor 176 outputs a plus (+) voltage at the convex portion and a minus (-) voltage at the concave portion of the crank gear 176A. The crank gear 176A is attached to the crank shaft, and as the engine speed increases, the output voltage also increases, as shown in FIG.

When the size of the gap (GAP) S for mounting the crank gear 176A and the sensor body 176B shown in FIG. 9 becomes wider, the output voltage becomes C as shown in FIG.
As in CRVhlow, it decreases with respect to RVhstd (design value). The output of the crank angle sensor 176 is input to the control means 66, and the waveform shaping section 66G in the control means 66 shapes the waveform as shown in FIG.

However, when the dimension of the mounting gap S between the crank gear 176A and the sensor body 176B becomes wider and the output voltage decreases, the threshold voltage value is not cut off as shown in FIGS. It will not be done. Further, depending on the gap S at that time, if the waveform becomes “0” or is near the threshold voltage at the very end, the result is that the number of pulses is different from the set value.

When the engine speed is low, such as during idling, an abnormal symptom is shown. However, when the engine speed increases, the engine becomes normal and confuses a driver or a repairer, causing a malfunction. It takes a lot of time to find out the cause of and the normal parts are unnecessarily replaced.

Sensor body 176 input to control means 66
The output CRVh voltage (crank signal voltage) from B is recorded for each engine speed, and as shown in FIG.
When it is lower than the imit (abnormality judgment voltage), and C
If there is RVh voltage (crank signal voltage) output,
If it is diagnosed that the mounting is defective and there is no CRVh voltage (crank signal voltage), it is determined that the wire is disconnected.

Sensor body 1 of this crank angle sensor 176
When 76B is not provided with the waveform shaping section, the failure of the crank angle sensor 176 is diagnosed as shown in FIG.

In the diagnosis of this failure, only the portion C after step 230 in FIG. 3 is different from the above-described diagnosis in the case where the sensor body is provided with the waveform shaping section. Therefore, only the different portion will be described. .

That is, if YES at step 230 in FIG. 3, the crank angle sensor 176 is diagnosed as shown in FIG.

First, it is determined whether the number of pulses of the crank signal voltage (CRVh) is CRVh> CRVlimit1 (step 302).

If step 302 is NO, in order to determine whether the crank angle sensor 176 has been improperly mounted or has a low voltage short circuit, first CRVh> CR
It is determined whether or not it is Vmin (step 304), and if this step 304 is YES, the crank angle sensor 176
(Step 306), and if step 304 is NO, a low voltage short circuit is made (step 308).

On the other hand, if YES at step 302, it is determined that CRCNT> 1 (step 310). If NO at step 310, the high voltage is short-circuited (step 312).

After the diagnosis in steps 306, 308, and 312, the process proceeds to step 246 in FIG. 5, the lamp or the like is turned on to notify the driver of the abnormality, and the program ends (step 248).

If step 310 is YES,
The procedure moves to the part E in FIG.

As a result, even in the crank angle sensor 176 having no waveform shaping section in the sensor body 176B, when at least one of the above conditions is satisfied when the cranking signal (starter signal) is abnormal, The normal crank angle sensor 176 will not be erroneously diagnosed as abnormal, and when the crank angle sensor 176 has an error due to an improper mounting, the improper mounting and the crank angle sensor 1
It is possible to distinguish between the damage of 76 itself, the short circuit of the wiring, the abnormality due to the damage of the parts of the crank angle sensor 176, etc. Therefore, when such a failure occurs, the failure time can be identified to determine the repair time. In addition, the working time for finding a defective portion or an abnormal portion is shortened, and the crank angle sensor 176 which is normally erroneously diagnosed as abnormal is not replaced unnecessarily, which reduces the cost of parts and working and reduces the working time. It can be shortened.

The present invention is not limited to the above-mentioned embodiment, but various application modifications are possible.

For example, the output value of the rotation angle sensor is stored in advance in the control means in correspondence with the engine load of each constant, and when there is a starter signal, the output value of the rotation angle sensor is the engine load at that time. It is also possible to easily carry out a failure diagnosis of the rotation angle sensor depending on whether or not it corresponds to. In addition, whether or not there is an output value of the rotation angle sensor in proportion to the change amount of the vehicle speed, etc. in consideration of the above-mentioned conditions, for example, considering the change amount of the vehicle speed etc. corresponding to the engine load. Also, it is possible to diagnose the abnormality of the rotation angle sensor.

[0072]

As is apparent from the above detailed description, according to the present invention, the change amount of the fuel injection amount calculated by the fuel injection change amount calculating section by inputting the starter signal from the starter signal detecting means is the set value. Condition that the battery voltage change amount calculated by the battery voltage change amount calculation unit is larger than the set value, and the intake air change amount calculated by the intake air change amount calculation unit is larger than the set value. The control means is provided with a failure diagnosis section that diagnoses a failure of the rotation angle sensor when at least one of the condition that the change amount of the intake pressure calculated by the pressure change amount calculation unit is larger than the set value is satisfied. Therefore, when the cranking signal (starter signal) is abnormal and at least one of the above conditions is satisfied, a normal rotation angle sensor is erroneously diagnosed as abnormal. In addition, when there is an abnormality due to poor rotation angle sensor installation, it is possible to distinguish between the poor installation and the failure due to damage to the rotation angle sensor itself, short circuit in the wiring, damage to the components of the rotation angle sensor, etc. Therefore, by identifying the faulty part when such a defect occurs, the repair time and the work time for finding the abnormal part can be shortened, and the rotation angle sensor which is normal but is erroneously diagnosed as abnormal It is possible to reduce the cost of parts and work, and to shorten the work time, because the parts are not replaced unnecessarily.

[Brief description of drawings]

FIG. 1 is a flowchart of failure diagnosis control.

FIG. 2 is a flowchart of part A in FIG.

FIG. 3 is a flowchart of part B of FIG.

FIG. 4 is a flowchart of part C of FIG.

5 is a flowchart of a portion D in FIGS. 2, 3, and 4. FIG.

FIG. 6 is a flowchart of a portion E in FIG.

FIG. 7 is a diagram illustrating set values for each condition.

FIG. 8 is a configuration diagram of a crank angle sensor having a waveform shaping unit.

FIG. 9 is a configuration diagram of a crank angle sensor having no waveform shaping section.

10 is a signal waveform diagram of the crank angle sensor of FIG.

11 is a diagram showing the relationship between the engine speed and the output voltage of the crank angle sensor of FIG. 9.

12 is a diagram showing the relationship between the waveform of the output voltage of the crank angle sensor of FIG. 9 and the waveform after waveform shaping.

FIG. 13 is a diagram showing a relationship between an engine speed and an output determination voltage of a crank angle sensor.

FIG. 14 is a flowchart of fault diagnosis control of a crank angle sensor having no waveform shaping section.

FIG. 15 is a system configuration diagram of a failure diagnosis control device.

FIG. 16 is a time chart of a conventional failure diagnosis.

FIG. 17 is a diagram illustrating a condition of failure diagnosis in the related art.

FIG. 18 is a time chart when a sensor is abnormal in the related art.

[Explanation of symbols]

2 Internal combustion engine 66 control means 66A Fuel injection change amount calculation unit 66B Battery voltage change amount calculation unit 66C Intake air change amount calculation unit 66D Intake pressure change amount calculation unit 66E Failure diagnosis unit 66F timer 68 Cam angle sensor 70 Intake pressure sensor 76 Crank angle sensor 102 ignition switch 108 Starter switch 136 cranking switch 138 Engine speed sensor

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3G084 CA01 DA27 EA07 EA11 EB22                       EC01 FA03 FA07 FA11 FA13                       FA35 FA36 FA38                 3G301 JB01 KA01 NA08 NE16 PA01B                       PA07B PE03B PE09Z PF16Z                       PG01B

Claims (2)

[Claims] 1. A rotation angle sensor that detects a rotation angle of a rotation shaft of an internal combustion engine and outputs a signal, and the rotation angle sensor fails according to the presence or absence of an output signal from the rotation angle sensor after an ignition signal is turned on. In a failure diagnosis control device for a rotation angle sensor of an internal combustion engine for diagnosing whether or not, a fuel injection change amount calculation unit capable of calculating a change amount of a fuel injection amount for a fixed time by providing a starter signal detection unit for detecting a starter signal , A battery voltage change amount calculation unit capable of calculating a change amount of the battery voltage for a fixed time, an intake air change amount calculation unit capable of calculating a change amount of the intake air for a fixed time period, and an intake air change amount for a fixed time period. And a fuel injection amount calculated by the fuel injection change amount calculation unit by inputting the starter signal from the starter signal detection means. Is larger than a set value, the battery voltage change amount calculated by the battery voltage change amount calculation unit is larger than a set value, and the intake air change amount calculated by the intake air change amount calculation unit is A failure in which the rotation angle sensor diagnoses a failure when at least one of a condition that is larger than a set value and a condition that the intake pressure change amount calculated by the intake pressure change amount calculation unit is larger than the set value is satisfied. A failure diagnosis control device for a rotation angle sensor of an internal combustion engine, comprising: a control unit provided with a diagnosis unit. 2. The failure diagnosis control device for a rotation angle sensor of an internal combustion engine according to claim 1, wherein the rotation angle sensor is a cam angle sensor or a crank angle sensor.