JPH0681706A - Malfunction detector for crank angle sensor of internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent such an engine trouble to not rotate from occurrence even when a starter switch is ON by performing a malfunction detection in a crank angle sensor when a signal from an intake air condition detecting means is on a normal output side beyond the specified value. CONSTITUTION:A crank shaft of an engine 6 is provided with a crank angle sensor 7 which outputs a reference angle signal per each reference angle according to revolution of the engine 6. The reference angle pulses showing the rotational position of the crank shaft are outputted, and these signals are inputted into a control unit 10 so as to be detected as the number of revolution. A signal showing an intake air amount is outputted from an air amount sensor 3 so as to be inputted into the control unit 10. Particularly when a signal from an intake air condition detecting means is on the normal output side beyond the specified value, the crank angle sensor detects malfunction. In this way, a misjudgment is prevented even when it is in a starter lock condition in which the engine does not rotate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a reference pulse of a crank angle sensor generated corresponding to a predetermined crank angle for detecting an operating state of an engine, and means for detecting an intake air state. The present invention relates to an abnormality detection device for a crank angle sensor of an internal combustion engine control device that controls an internal combustion engine.

[0002]

2. Description of the Related Art An internal combustion engine control apparatus for controlling an internal combustion engine using a reference pulse generated corresponding to a predetermined crank angle for detecting an operating state of the engine and a means for detecting an intake air state. As an abnormality detection device for a crank angle sensor, as described in JP-A-57-169610, it is determined whether the engine is rotating or not by turning on / off a starter switch.
There is a device which detects the abnormality of the crank angle sensor depending on whether or not there is a crank angle pulse when the starter switch is turned on.

However, in such an abnormality detecting device, even if the starter switch is ON, an erroneous determination is made, for example, in a starter locked state where the engine is not rotating. The abnormality of the crank angle sensor can be detected only in a specific period after the engine starts rotating.
There is a problem.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to make an erroneous determination even when the starter switch is ON but the engine is not rotating, for example, in a starter locked state. There is no. An object of the present invention is to provide an abnormality detecting device for a crank angle sensor of an internal combustion engine control device, which is capable of detecting an abnormality in the crank angle sensor in any period after the engine starts rotating.

[0005]

According to the present invention, a reference pulse of a crank angle sensor generated corresponding to a predetermined crank angle for detecting an operating state of an engine and a means for detecting an intake air state are provided. In a control device for an internal combustion engine that controls an internal combustion engine using the above configuration, a crank angle sensor is detected to be abnormal when the signal from the intake air state detection unit is on the normal output side of a predetermined value.

[0006]

In the internal combustion engine, the reference pulse of the crank angle sensor generated corresponding to the predetermined crank angle for detecting the operating state of the engine and the means for detecting the intake air state are used to control the internal combustion engine. The control device is configured to detect the abnormality of the crank angle sensor when the signal from the intake air state detection unit is on the normal output side from the predetermined value.

Further, the intake air condition detecting means is provided with first detecting means for generating a first signal upon detecting that the power supply is operated in an ON state, and a predetermined time from the first signal. Configure to start later.

Further, a second detecting means for detecting that the starter switch has been operated to an ON state is provided, and the rotation of the engine is started when the signal by the detecting means of the intake air state is on the normal output side from a predetermined value. It is configured to determine.

On the other hand, a means for detecting an abnormality is provided in each of the intake air state detecting means and the second detecting means, and when either of them is detected as abnormal, the abnormality detection of the crank angle sensor is stopped. To configure.

As a result, even if the starter switch is ON, there is no erroneous determination even when the engine is not rotating, for example, in the starter locked state. It is possible to provide an abnormality detection device for a crank angle sensor of an internal combustion engine control device that can detect an abnormality in the crank angle sensor in any period after the engine starts rotating.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An abnormality detecting device for a crank angle sensor of an internal combustion engine according to the present invention will be described in detail below with reference to embodiments shown in the drawings.

FIG. 2 shows an example of an engine system to which the present invention is applied. In the figure, the air to be taken in by the engine is taken in through an inlet portion 2 of an air cleaner 1, and a heat ray for detecting the amount of intake air. The air flow sensor 3, the duct 4, and a throttle valve body 5 in which a throttle valve for controlling the air amount is accommodated, and is introduced into each cylinder of the engine 6.

A signal representing the intake air amount is output from the air amount sensor 3 and is input to the control unit 10.

Further, a throttle sensor 13 is attached to the throttle valve body 5 so as to output the opening of the throttle valve and input it to the control unit 10.

A crank angle sensor 7 that outputs a reference angle signal for each reference angle in accordance with the rotation of the engine is provided on the crank shaft of the engine, and a reference angle pulse indicating the rotational position of the crank shaft is output. Then, these signals are also input to the control unit 10 and detected as the number of revolutions.

On the other hand, in order to start the engine, a power switch 8 that interlocks with a key switch and a starter switch 9 that interlocks with the drive of the starter are provided and are input to the control unit 10.

Fuel is pressurized from a fuel tank by a fuel pump, adjusted to an appropriate pressure by a pressure regulator, and then supplied to each cylinder of the engine 6 by an injector 11.

Next, reference numeral 13 is a dist (distributor), which is an output from the control unit 10 and whose ignition timing is controlled by the ignition coil 12.

As shown in FIG. 3, the main part of the control unit 10 is composed of an MPU, a ROM, a RAM, an A / D converter, etc., and a water temperature sensor 15 and various other sensors for detecting the operating state of the engine. Signal is input as an input, predetermined arithmetic processing is executed, various control signals calculated as the arithmetic result are output, and the control signals for fuel injection for four cylinders are output to the injector 11 as described above. The ignition timing control signal and the control signal to the ISC valve 14 that adjusts the air amount at the time of idling are configured to be performed.

Next, the present invention will be described.

FIG. 1 shows the basic configuration of the present invention.
Check that the output values of the crank angle pulse detection means, the intake air state detection means, the power ON state detection means, the engine speed N calculation means, the starter switch ON detection means, and the intake air state detection means are on the normal output side from the predetermined value. A means for judging, a means for judging the start of rotation, a means for judging the passage of a predetermined time by means of a power-on state, means for detecting an abnormality in the intake air state, a means for detecting an abnormality in a starter switch, and a means for determining an abnormality in a crank angle sensor To be done.

Regarding the abnormality determination means of the crank angle sensor in this embodiment, first, the abnormality determination means at the time of starting the engine will be described with reference to FIGS. 1 and 4.

When the power-on state detecting means detects that the power is turned on, for example, in conjunction with turning on the ignition key, the elapsed time 1 timer starts measuring time. This is because, for example, due to the characteristics of the hot air type air amount sensor by the intake air state detecting means, an excessive output period that occurs in synchronization with the supply of the sensor power supply is avoided, a noise input that occurs in synchronization with the power ON, and the like are avoided. For the purpose, for example, the acquisition of the output of the air amount sensor is canceled for a predetermined time of about 500 ms.
When the timer for elapsed time 1 elapses a predetermined time, the means for determining the elapse of the predetermined time starts capturing the output of the air amount sensor.

Further, the starter switch ON detecting means detects that the starter switch is turned on and the starter is started to rotate. At this time, when there is no starter lock state and the engine starts to rotate normally, the output of the air amount sensor is not rotating and the engine starts rotating from the initial output state when the intake air amount is 0. Then, when the air is sucked, the output value shifts to the normal output value side. The state at this time is set to a value lower than the air amount during cranking, for example, when the output of the air amount sensor is larger than the initial output state by means of determining that the output value is on the normal output side than the predetermined value. When it is larger than the predetermined value, it is recognized that the engine is surely rotating, and the rotation start of the engine is judged by the means for judging the rotation start. Therefore, the abnormality determination of the crank angle sensor at the time of starting the engine starts when the rotation start determination ends.

If the crank angle sensor is normal, a crank angle pulse corresponding to a predetermined crank angle is input.
If the crank angle sensor is abnormal, the crank angle pulse will not be input, but at this time, the period for which the crank angle pulse is not detected is measured by the elapsed time 2 timer, and the crank angle pulse continues for the elapsed time 2 When the time is not detected, it is determined that the crank angle sensor is abnormal for the first time. This is for avoiding the abnormality determination in the state where the crank angle pulse is not detected temporarily for a short period of time such as a momentary interruption due to some factor, and to perform the abnormality determination for a certain length of time, for example, for about 1 second.

Further, the abnormality determination result is set so as to be held in a non-volatile memory, and the intake air condition detecting means and the starter switch ON detecting means, which are the medium of the crank angle sensor abnormality detecting means, are also abnormal. A detection means is provided. When it is determined that either of the two is abnormal, accurate determination cannot be performed, and therefore the crank angle sensor is not detected as abnormal but is determined as normal.

Further, once the rotation start is determined, the crank angle sensor is determined to be abnormal until the engine is stopped and the output of the air amount sensor is larger than a predetermined value regardless of whether the starter switch is ON or OFF. To do so.

Even if the rotation start determination is not performed, if the output of the air amount sensor is always larger than a predetermined value, the crank angle sensor may be determined to be abnormal. The sex is a little inferior. Further, the intake air state detecting means may be a pressure sensor or the like other than the air amount sensor.

The basic concept of the present invention has been described above, and the software configuration will be described below with reference to a flowchart.

5 and 6 are flow charts of the embodiment of the present invention. The program corresponding to this flow chart is configured to run every interruption of crank angle pulse input and every fixed time (for example, every 80 ms).

In step 100, each time the crank angle pulse is input, the time interval is converted into the number of revolutions.

In step 200, after detecting the power-on state, 8
It is a program that runs every 0 ms. The flag IGON is
The flag for judging the elapsed time 1 is initially 0, and the timer for the elapsed time 1 is incremented from 0 by 1 in step 201. In step 202, the process proceeds to step 310 before the count of the timer reaches a predetermined value, for example, 7, and when it reaches 7, after 560 ms has elapsed in time, the flag IGO is set.
N = 1 is set. Once the flag IGON = 1 is set, the process proceeds from step 200 to step 210 to start taking in the air amount sensor.

Next, in step 220, it is determined whether the starter switch is OK. If it is NG, the process proceeds to step 310. If it is OK, it is determined in step 221 whether the starter switch is ON. Proceed to 260. If it is ON, it is determined in step 230 whether the output of the air amount sensor is OK. If it is NG, the process proceeds to step 310. If it is OK, in step 240 the output value of the air amount sensor is normal than the predetermined value. Determine if it is on the output side. If it is smaller than the set predetermined value, the process proceeds to step 310, and if it is larger than the predetermined value, it is recognized that the engine is surely rotating, and the means for determining the start of rotation at step 250 makes it 0 in the initial state. The starting start flag that has been set is determined, the starting start flag is set in step 251, and the start of rotation of the engine is determined. Once the start flag is set, it is considered that the start determination has finished from the next time,
The process proceeds directly from step 250 to step 290.

Step 290 is a crank angle sensor abnormality determination routine, which monitors whether or not there is a crank angle pulse by separately checking whether or not there is an interrupt for each crank angle pulse input. When there is no crank angle pulse input, Step 29
At 1, the timer for elapsed time 2 is incremented by 1. Step two
This routine ends as it is before the count of the timer reaches a predetermined value, for example 13, by 92. When the crank angle pulse is 13 seconds, and the crank angle pulse is not continuously detected for the elapsed time 2 after about 1 second has elapsed, the process proceeds to step 293, the crank angle sensor NG flag = 1 is set, and the crank angle sensor is not detected for the first time. Is determined to be abnormal.

If a pulse is input in step 290, it is immediately determined once in step 300 that NG flag = 0, that is, OK, and in step 310, the abnormal elapsed time 2
The timer for clearing is cleared and this routine ends.

Further, once it is determined that the rotation has started, the process proceeds from step 221 to 260 even if the starter switch is OFF until the engine is stopped. 29
Then, the routine proceeds to 0, the abnormality determination of the crank angle sensor is similarly performed, and the present routine is ended.

Next, FIG. 6 shows an abnormality detecting means for the air amount sensor and the starter switch, which is similarly constructed so as to run at regular intervals (for example, every 80 ms). First, the air amount sensor checks the elapsed time 1 in step 400, and when it has not elapsed, does not detect an abnormality and proceeds to step 490 to clear the timer. When the elapsed time 1 has elapsed, check the rotation speed N,
Abnormality is not detected when the speed is less than 500 rpm. this is,
This is to avoid the parallel detection with the abnormality detection of the crank angle sensor at the time of starting. When the speed is 500 rpm or more, step 420,
At 430, it is determined whether or not the air amount sensor is between the predetermined voltages 1 and 2 which are the upper and lower limit values of the normal range. If it is out of the upper and lower limit values, the timer for elapsed time 3 is incremented by 1 in step 450. Step 460
Thus, before the count of the timer reaches a predetermined value, for example, 7, the process proceeds to step 500 as it is. 7. After about 560 ms has passed in time, NG is given at step 470.
When the flag is set to 1, it is determined that the air amount sensor is abnormal.

When the starter switch abnormality is detected, the number of revolutions N is checked in step 500, and when it is less than 1500 rpm, it is checked in step 510 whether it is within the upper and lower limit rotation set values corresponding to cranking rotation. When the rotation is other than the ranking rotation, the abnormality is not detected and this routine is finished. When it is within the upper and lower limit rotation set values, step 52
At 0, it is determined whether the starter switch is ON. If it is at ON, NG flag = 0 is set at step 550, and OK is determined.
If it is OFF, the NG flag is set to 1 in step 540 and it is determined that the starter switch is abnormal. On the other hand, if it is 1500 rpm or more in step 500, step 530
Then, it is determined whether or not the starter switch is OFF. If the starter switch is OFF, NG flag = 0 is set in step 555, and OK is determined.

If it is ON, the NG flag is set to 1 in step 540, it is determined that the starter switch is abnormal, and this routine is ended. Each NG flag is held in the non-volatile memory.

If it is determined that the crank angle sensor is abnormal, the rotational speed N is calculated so as to be 0 rpm. In this routine, no abnormality is detected. Become.

[0041]

Industrial Applicability The internal combustion engine is controlled by using the reference pulse of the crank angle sensor, which is generated corresponding to the predetermined crank angle for detecting the operating condition of the engine, and the means for detecting the intake air condition. In the control device for an internal combustion engine, even if the starter switch is ON, there is no erroneous determination even when the engine is not rotating and the starter is locked. It is possible to provide an abnormality detection device for a crank angle sensor of a control device for an internal combustion engine, which can detect an abnormality in the crank angle sensor in any period after the engine starts rotating.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram.

FIG. 2 is a system diagram.

FIG. 3 is a configuration diagram of a control unit.

FIG. 4 is an explanatory diagram of an example of the present invention.

FIG. 5 is a diagram showing a flowchart 1.

FIG. 6 is a diagram showing a flowchart 2;

[Explanation of symbols]

3 ... Air amount sensor, 6 ... Engine, 7 ... Crank angle sensor, 9 ... Starter switch, 10 ... Control unit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahide Sakamoto 2520 Takaba, Katsuta City, Ibaraki Prefecture Hitachi Ltd. Automotive Equipment Division

Claims (4)

[Claims] 1. An internal combustion engine for controlling an internal combustion engine using a reference pulse of a crank angle sensor generated corresponding to a predetermined crank angle for detecting an operating state of an engine, and means for detecting an intake air state. In a control device for an engine, a crank angle sensor for an internal combustion engine is configured to detect an abnormality of a crank angle sensor when a signal from an intake air state detection unit is on a normal output side from a predetermined value. Abnormality detection device. 2. A power source for the intake air state detecting means is O
A crank of an internal combustion engine, comprising first detection means for generating a first signal when it is operated in an N state, and starting a predetermined time after the first signal. Abnormality detection device for angle sensor. 3. A second detection means for detecting that the starter switch has been operated to an ON state is provided, and rotation of the engine is started when a signal from the intake air state detection means is on a normal output side from a predetermined value. An abnormality detecting device for a crank angle sensor of an internal combustion engine, characterized in that 4. A means for detecting the intake air condition, and the second device.
Of the crank angle sensor of the internal combustion engine is configured to stop the abnormality detection of the crank angle sensor when any of them is detected to be abnormal. Detection device.