JPS6367665B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle electronic control device diagnostic device for diagnosing and confirming that various electronic control devices installed in vehicles such as automobiles are operating normally when the vehicle is started. It is.

Vehicles such as automobiles are equipped with various vehicle control devices such as anti-skid brake devices, but if these devices break down, there may be a danger that the braking action of the brake device will no longer work. Therefore, when these vehicle control devices break down, an electronic control device is installed in the vehicle that operates in response to the abnormal signal, and the output from the output circuit of this electronic control device is used to control the anti-skid brake that has failed. It is now possible to forcibly maintain the operation of the vehicle control device on the safe side, such as by stopping the operation of the device, or to issue an alarm. Many of these electronic control devices are designed so that once they start operating, the output from their output circuit is maintained until a reset operation is performed.

By the way, in a vehicle equipped with such an electronic control device, it is often necessary to send a diagnostic signal to the electronic control device to diagnose and confirm that the device operates normally. In that case, if you do not reset the electronic control device after confirming this, the operation of vehicle control devices such as anti-skid brake devices may remain stopped, or the alarm may remain activated and may occur in the event of an actual failure. This may even increase the risk, such as making it impossible to confirm the situation. Therefore, in order to diagnose a failure in such an electronic control device, two operations are required: adding a diagnostic signal and resetting it. However, since this reset operation is generally a completely different type of operation than the operation of applying a diagnostic signal, performing this reset operation may be forgotten.

In view of the above-mentioned points, the present invention provides a diagnostic system for a vehicle electronic control unit that allows inputting a diagnostic signal to the electronic control unit and resetting it by operating the engine switch, which is always performed when starting the vehicle. The purpose is to provide a device.

According to the present invention, when the power supply circuit of the engine starting device is closed, a diagnostic signal is generated and applied to the electronic control device, and when the power supply circuit of the engine starting device is opened, the output of the electronic control device is A vehicle electronic control unit diagnostic device is provided which disconnects and resets a self-holding circuit provided between a circuit and a power source.

Hereinafter, one embodiment of the present invention will be explained with reference to the drawings. In FIG. It is becoming more and more popular. When this control signal a indicates an abnormality in the vehicle control device 1, the electronic control device 2 is activated, and the output circuit 4 generates the output signal b based on the signal sent from the control circuit 3. ing. This output circuit 4 is also connected to a self-holding circuit 5, and not only applies an output voltage to the self-holding circuit 5, but also generates an output signal b when a voltage is applied from the self-holding circuit 5. There is. The output signal b is guided to the vehicle control device 1 or an alarm device (not shown), and is used to forcibly maintain the operation of the vehicle control device 1 on a safe side, for example, to stop its operation, or to issue an alarm. I'm starting to do that.

The self-holding circuit 5 includes a relay coil 6 and a relay contact 7 that closes when the relay coil 6 is energized.
It is configured as a relay consisting of. However, this self-holding circuit 5 can also be constructed as a flip-flop circuit.

The engine switch 8 includes a contactor 9 whose one end is connected to a power source (battery) _VB , and four terminals o, p, q, and r arranged at equal intervals. Among these, terminals p, q, and r are connected to an accessory circuit ACC, an ignition circuit IG, and an engine starting device ST, respectively. Further, the terminal o is a terminal for disconnecting the power supply _VB . The tip of the contactor 9 has a width sufficient to simultaneously contact two adjacent terminals, for example, terminal p and terminal q. Therefore, the contact 9 and the terminal p,
q and r are power supply _VB , accessory circuit ACC, ignition circuit IG or engine starting device
It constitutes a switch between ST and ST.

The accessory circuit terminal p and the engine starting device terminal r are also connected to the self-holding circuit 5, and these terminals p and r and the contact 9 connect the power supply.
The circuit from _VB to the self-holding circuit 5 is opened and closed. The ignition circuit terminal q is also connected to the electronic control device 2, and can supply the power supply _VB voltage to devices such as transistors in the control circuit 3 and output circuit 4, which normally require voltage to be applied. I'm starting to be able to do it.

A diagnostic signal generating device 10 is further connected to the engine starting device terminal r, and a diagnostic signal generated by this generating device is applied to the control circuit 3. This diagnostic signal has the same waveform, polarity, amplitude, etc. as the control signal a when the vehicle control device 1 is abnormal, and by adding this diagnostic signal, the electronic control device 2 starts operating. ing.

Thus, according to the normal operation when starting a vehicle, from the power-off state where the contact 9 of the engine switch 8 is in contact only with the terminal o, the contact 9 is operated to connect the terminals p, q, and r. When they are brought into contact with each other, first, in a state where the contactor 9 is in contact only with the terminal p, the power supply V _B and the accessory circuit ACC are connected, and the power supply V _B voltage is applied to the self-holding circuit 5. However, at this time, the relay contact 7 of the self-holding circuit 5 remains open, and the electronic control device 2 does not perform any operation. Next, when the contact 9 comes into contact with the terminals p and q at the same time,
The connection between the power supply V _B and the ignition circuit IG is also closed, and the power supply V _B voltage is also applied to the transistors of the electronic control unit 2 to prepare them for operation, but there is no output from the output circuit 4. do not have. Next, the contactor 9 is moved away from the terminal p and brought into contact with only the terminal q. At this time, the self-holding circuit 5 and the power supply _VB are temporarily disconnected.

When the contactor 9 is operated to the maximum, the contactor 9 contacts terminals q and r at the same time. At this time, a circuit is closed between the power source V _B and an engine starting device ST such as an engine starting motor, and the engine is started. At the same time, the power supply V _B voltage is also guided to the self-holding circuit 5 and the diagnostic signal generator 10 .
When the diagnostic signal generator 10 is energized, it generates a diagnostic signal and sends it to the control circuit 3 of the electronic control unit 2 . Since this diagnostic signal is similar to the control signal a indicating a failure of the vehicle control device 1, the control circuit 3 starts operating and generates the output signal b from the output circuit 4, and also outputs the output signal b from the self-holding circuit 5. Apply output voltage. This output voltage causes the relay coil 6 of the self-holding circuit 5 to
is energized and closes its relay contact 7. As a result, the power source _VB voltage is applied to the relay coil 6, and the relay contact 7 is self-held. Therefore, even if the diagnostic signal is cut off and the control circuit 2 stops operating, the voltage of the power supply V _B is applied from the self-holding circuit 5 to the output circuit 4, so the output signal b from the output circuit 4 continues. Served. In this way, by confirming that the output signal b is output, it is possible to diagnose whether or not the operation of the electronic control device 2 is normal. Also, if the self-holding circuit 5 does not work and the relay contact 7 remains open even if the contact 9 of the engine switch 8 is operated, this can be taken out as the alarm signal c.
A failure of the electronic control device 2 or the self-holding circuit 5 can be confirmed by activating the alarm in response to the alarm signal c.

In this way, after the engine has been started and the operation of the electronic control unit 2 etc. has been diagnosed and confirmed, when the contact 9 is reversed in accordance with the normal operation of the engine switch 8, the contact 9 first connects to the terminal. move away from r. As a result, the supply of the power supply voltage V _B to the diagnostic signal generator 10 and the self-holding circuit 5 is cut off, so that the relay coil 6 of the self-holding circuit 5 is no longer excited, and the relay contact 7 is opened. The contact 9 is
It is returned to a position where it contacts terminals p and q at the same time and is held there, but in that state, the self-holding circuit 5
is connected to the power supply _VB again, so the self-holding circuit 5 is reset.

The vehicle runs in this state, but the vehicle control device 1
When a failure occurs, a control signal a indicating the abnormality is applied to the electronic control device 2, and the control circuit 3 starts operating to generate an output signal b from the output circuit 4, and the relay coil 6 of the self-holding circuit 5 is activated. Excite. This closes relay contact 7 and terminal p
It is self-maintained by the voltage of the power supply V _B sent from the side, and the power supply V _B voltage is sent to the output circuit 4 to continue generating the output signal b. That is, in this state, it functions similarly to a conventional electronic control device and self-holding circuit.

Fig. 2 shows a specific example in which the device shown in Fig. 1 is applied to a fail-safe device of an anti-skid brake system for a vehicle, in which the braking action of the braking device is inhibited when the braking force of the braking device is too large. A solenoid 11 of a pressure-side electromagnetic on-off valve for supplying high-pressure hydraulic oil is connected to a terminal q in FIG. 1 via a transistor 12. An output signal from a computer (not shown) is applied to the base terminal s of this transistor 12 to determine whether or not the braking force of the braking device is too large. At times, the transistor 12 is activated to apply the power supply V _B voltage to the solenoid 11 via the terminal q. This voltage is applied via a rectifier 13 to a timer circuit 19 consisting of amplifiers 14 and 15, a resistor 16, a capacitor 17, and a rectifier 18. This timer circuit 19
This corresponds to the control circuit 3 in the figure. The input side of the timer circuit 19 is also connected to the terminal r in FIG. In this case, what corresponds to the diagnostic signal generating device 10 in FIG. 1 is a switch constituted by the contactor 9 and the terminal r in FIG. 1. The output signal of the timer circuit 19 is converted into a control voltage by a resistor 20 and applied to the base of a transistor 21. Transistor 21 is provided between terminal q in FIG. 1 connected to power supply _VB and relay coil 22, and when a base voltage is applied to transistor 21, relay coil 22 is excited. This relay coil 22 forms part of the fail-safe device of the anti-skid brake device, and when this coil 22 is excited, the anti-skid brake device is forced to stop operating. . Therefore,
The output circuit 4 in FIG. 1 corresponds to this transistor 21 and relay coil 22. At the same time, when this relay coil 22 is energized, a normally open relay contact 23 is closed, but this contact 23 is connected to the terminal p, which is connected to the relay coil 22 and the power supply _VB in FIG.
r, so that when the contact 23 is closed and the voltage of the power supply V _B is introduced to the relay coil 22, the contact 23 is self-held. Therefore, the relay coil 22 and the contacts 23 also constitute the self-holding circuit 5 shown in FIG.

Thus, in this anti-skid brake device, when the braking force of the brake device is too large, the solenoid 11 is energized by the power supply voltage from the terminal q, and the braking action of the brake device is suppressed. When the anti-skid brake system is operating normally, the braking inhibit time, ie, the time during which transistor 12 is turned on, is short, and therefore the time during which voltage is applied to timer circuit 19 through rectifier 13 is also short. Therefore, timer circuit 19 does not generate an output signal. However, due to a malfunction of the anti-skid brake device's computer, etc.
Transistor 12 may be placed in a conductive state for an extended period of time. In this state, the solenoid 11 is energized and inhibits the braking action of the braking device, so it is extremely dangerous for this state to continue. This is where this failsafe device comes into play. That is, the power supply V _B voltage is applied to the timer circuit 19 through the rectifier 13 for the same time as the time when the solenoid 11 is energized, and when that time becomes longer than the time constant determined by the resistor 16 and capacitor 17, the timer circuit 19 outputs A signal is generated to activate transistor 21. Thereby, the power supply _VB voltage led from terminal 9 excites relay coil 22, and forcibly stops the operation of the anti-skid brake device. At the same time, the relay contact 23 is closed and the power supply V _B voltage from terminal p is applied to the relay coil 2.
2, so even if the timer circuit 19 no longer outputs a signal, the fail-safe device continues to operate.

Although the electronic control device including the timer circuit 19 and the like operates as described above, it is necessary to constantly monitor whether it operates normally. In order to diagnose and confirm this, it is sufficient to operate the engine switch 8 shown in FIG. 1 and bring the engine starting device terminal r into contact with the contactor 9.
Normally, when starting a vehicle, the engine starting motor is driven for several seconds, during which time the power supply _VB is connected to terminal r.
Since the power supply V _B voltage is applied from the terminal r, the voltage is input to the timer circuit 19 as a diagnostic signal. Since this time is longer than the time constant of timer circuit 19, timer circuit 19 generates an output signal, causing transistor 21 to conduct. Therefore, relay coil 22 is energized and relay contact 23 is closed. When the electronic control device such as the timer circuit 19 does not operate normally, or when the relay coil 22 and relay contact 23 that make up the self-holding circuit are out of order, the relay contact 23 cannot be closed, so an alarm signal c is generated. and activate the alarm. Therefore, a failure in the electronic control device or self-holding circuit can be diagnosed simply by checking the operation of the alarm. After this confirmation, if the contactor 9 of the engine switch 8 is returned to the position where it contacts terminals p and q at the same time, the self-holding circuit will be reset.
It is similar to that in FIG.

As described above, according to the present invention, the diagnostic signal is input to the electronic control device and the self-holding circuit is reset by simply operating the engine switch 8 normally when the vehicle is started. This provides a vehicle electronic control unit diagnostic device that can diagnose and confirm the operation of the electronic control unit at all times, and that is automatically reset after the confirmation.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of essential parts showing one embodiment of the vehicle electronic control device diagnostic device of the present invention, and FIG. 2 is a diagram showing the application of the vehicle electronic control device diagnostic device of the present invention to an anti-skid brake system. FIG. 2 is an electrical circuit diagram of a main part specifically showing an example of the above. DESCRIPTION OF SYMBOLS 1... Vehicle control device, 2... Electronic control device, 3... Control circuit, 4... Output circuit, 5... Self-holding circuit, 8...
Engine switch, 9...Contactor, 10...Diagnostic signal generator, _VB ...Power source, p, q, r...Terminals each forming a switch together with contactor 9, a...Control signal, b...Output signal.

Claims (1)

[Claims] 1. By operating in response to control signal a,
In a vehicle electronic control device diagnostic device for diagnosing and confirming the operation of an electronic control device 2 whose output circuit 4 is connected to a power source V _B and whose connection is self-held by a self-holding circuit 5, an engine starting device is used. A switch 9,r that connects and disconnects _the
A diagnostic signal generating device 10 is provided which generates a diagnostic signal similar to the control signal a when the switch is closed and sends this diagnostic signal to the electronic control device 2, and the self-holding circuit 5 controls the switches 9, r. A vehicle electronic control unit diagnostic device connected to said power supply _VB via. 2. In the vehicle electronic control device diagnostic device according to claim 1, after the switch 9, r is opened, the switch 9, p is connected to the self-holding circuit 5 to the power source _VB . Equipped with a vehicle electronic control unit diagnostic device.