JPS628B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a failure diagnosis circuit for various control detectors in a vehicle.

Conventionally, several diagnostic methods for electronic control units installed in vehicles have been proposed. However, there is room for improvement in terms of whether or not it is possible to easily diagnose failures in the detector, which is the basis of the operation of the electronic control device.

There is usually a predetermined positional relationship between the accessory contact, the ignition contact, and the starter contact in the engine switch of a vehicle. That is, when operating the engine switch, first the accessory contact is connected to the power source, then the accessory contact and the ignition contact are simultaneously connected to the power source, and then when the starter contact is connected to the power source, the ignition contact is connected to the power source. The positional relationship of the respective contacts is configured such that the accessory contact remains connected to the power source, but the accessory contact can be disconnected from the power source.

The present inventor has accomplished the present invention by effectively utilizing the positional relationship of the contacts in the engine switch of a vehicle as described above.

An object of the present invention is to provide an engine having an accessory contact, an ignition contact, and a starter contact, and configured such that the accessory contact is not connected to the power source when the ignition contact and the starter contact are connected to the power source. In a vehicle having a switch, the signal generating element of the control detector can be connected to a power source via the accessory contact, and the receiving element of the control detector can be connected to a power source via the ignition contact, It is an object of the present invention to provide a failure diagnosis circuit for various control detectors in a vehicle, in which an abnormal signal detection circuit is provided on the output side of the receiving element.

Therefore, an object of the present invention is to easily establish conduction and non-continuity between the signal generating element and the receiving element of a control detector by utilizing the positional relationship and operational relationship of each contact point provided in a vehicle engine switch. It is to diagnose.

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

In this embodiment, a failure diagnosis circuit for a detector of an optical system used in a device for adjusting the height of a vehicle will be described.

In FIG. 1, 1 is a detector, and the detector 1 is composed of a light emitting element 2 such as a photodiode which is a signal generating element and a light receiving element 3 such as a phototransistor which is a receiving element. Detector 1 is an optical system detector. The detector 1 is attached to either the lower part or the upper part of the vehicle body, and the other part has a light shielding plate 4 interposed between the light emitting element 2 and the light receiving element 3.
will be provided. When the suspended part (spring part) of the vehicle body moves up and down, the light emitting element 1 and the light receiving element 2
The relative position of the light shielding plate 4 changes, and the change in the position of the slit 4a formed in the light shielding plate 4 causes a light-transmitting state and a light-blocking state in the detector 1, thereby detecting the height state of the vehicle. can do. The ON and OFF operations of the light receiving element 3 are transmitted to the control circuit as a control signal a.

5 is an engine switch. The terminal 6 of the engine switch 5 is a terminal of a battery 7, and the terminal 6 is provided with a switch movable part 8 having a contact piece 8a that is rotatable around the terminal 6. Terminal 9 is an off terminal, terminal 10 is an accessory terminal, and terminal 11
is an ignition terminal, and terminal 12 is a starter terminal. By rotating the switch movable part 8,
Terminals 10, 11 or terminals 11, 12 can be connected to battery 7 at the same time.

The light emitting element 2 is connected to an accessory terminal 10, and the light receiving element 3 is connected to an ignition terminal 11.

In FIG. 2, 13 is a control calculation circuit;
14 is an actuator. Control calculation circuit 13
functions to operate the actuator 14 by performing calculations based on the control signal a output from the light receiving element 3. When the actuator 14 operates, the vehicle height is adjusted by moving the vehicle height up or down in accordance with the purpose of vehicle height adjustment. The control calculation circuit 13 and the actuator 14 are connected to the battery 7 via the ignition terminal 11,
Electricity is provided.

15 is an abnormal signal detection circuit;
The signal a output from the light receiving element 3 is inputted to the sensor 3, and when the signal a is abnormal, it outputs a signal and activates the alarm 16 to notify the driver of this.

Further, an operating coil 17 that is excited by the output signal is provided on the output side of the detection circuit 15, and a normally closed switch 18 that opens and closes when the operating coil 17 is energized or de-energized is connected to the terminal 11 of the actuator 14. It is installed on the conductor wire.

In the above configuration, failure diagnosis of the detector 1 is performed as follows.

When the engine is started, the switch movable part 8 is connected to the ignition terminal 11 and the starter terminal 12 by the contact piece 8a, so that the light receiving element 3
is energized, and the light emitting element 2 is not energized. Therefore, since the light emitting element 2 does not emit light when the engine is started, the output signal of the light receiving element 3 always contains light L.
In the absence of input, the signal is generated.

Therefore, when the engine is started, if the signal that enters the detection circuit 15 from the light receiving element 3 is a "no light received" signal (that is, when the light receiving element 3 is off and no signal enters the detection circuit 15), is determined to be normal, and if it is a signal indicating that "light has been received" (that is, when the light receiving element 3 is turned on and a signal is input to the detection circuit 15), it is determined to be abnormal.
When a signal indicating that "light has been received" enters the detection circuit 15, the detection circuit 15 outputs an output signal based on this signal. This output signal causes alarm 16
is activated, and the operating coil 17 is energized and the switch 18 is turned off to stop the operation of the actuator 14.

As described above, when the engine is started, if the detector 1 is normal, a signal related to the off operation of the light receiving element 3 is originally input to the detection circuit 15; The generation of a signal is used to diagnose that the detector 1 is in a fault condition.

The processing method of the arithmetic circuit 13 that controls the vehicle height adjustment based on the output signal of the detector 1 is set so that when there is no output signal from the detector 1, the control operation is set to release the air pressure. By doing so, the pressure air supply side of the detector 1 can be checked at least once every time the engine is started.

Furthermore, in the above embodiment, a single optical system detector 1 has been described, but even if there are multiple detectors 1, diagnosis can be made in the same manner. The present invention can also be applied to non-contact switches and the like to similarly diagnose failures.

As is clear from the above description, according to the present invention,
By using the power connection time difference that occurs due to the positional relationship of the accessory contact, ignition contact, and starter contact of the engine switch installed in the vehicle, it is possible to determine the normal status or abnormality of a detector such as a vehicle height detector of a vehicle height adjustment device. By making it possible to detect the state, it is possible to easily diagnose the failure state of various control detectors with a low-cost circuit configuration.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; Fig. 1 is a circuit diagram showing the connection structure between each contact of the engine switch and the detector, and Fig. 2 is a circuit diagram showing the overall configuration of the fault diagnosis circuit in block diagram form. It is a diagram. In the drawing, 1 is a detector, 2 is a light emitting element, 3 is a light receiving element, 4 is a light shielding plate, 5 is an engine switch, 1
0 is an accessory terminal, 11 is an ignition terminal, 12 is a starter terminal, 15 is an abnormal signal detection circuit, and 16 is an alarm.

Claims (1)

[Claims] 1 Accessory contacts, ignition contacts,
In a vehicle having an engine switch that has a starter contact and is configured such that the accessory contact is not connected to the power source when the ignition contact and the starter contact are connected to the power source, the signal generating element of the control detector is connected to a power source via the accessory contact, and a receiving element of the control detector is connectable to the power source via the ignition contact, and an abnormal signal detection circuit is provided on the output side of the receiving element. A fault diagnosis circuit for various control detectors in a vehicle, characterized by: