JPH05118306A - Failure detecting device for actuator - Google Patents

Abstract

PURPOSE:To provide a failure detecting device for a valve for hydraulic control, which cannot be turned off during its operation in order to ensure the continuity of the control. CONSTITUTION:While an ignition switch (IG SW) 12 is turned on, battery voltage of 12V is impressed on both a pressure governing valve 4 for clutch and an F/S valve 6 via transistor 25. When the IG SW 12 is turned off, a CPU 21 controls the transistor 25 so as to turn off the movement of the valves 4, 6 and judges whether an output wave form of a hydraulic sensor 5 exceeded a prescribed threshold within 500 milliseconds or not. The CPU 21 judges that it is normal if the waveform exceeded the threshold but that a failure is caused if not exceeded, and the CPU 21 puts this judgment in a memory. After this judgment. the CPU 21 turns a main power source 22 off in order to shift to a low power consumption mode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator failure detecting device, and more particularly to a failure detecting device suitable for detecting a failure of a hydraulic control valve in a vehicle hydraulic circuit.

[0002]

2. Description of the Related Art An example of a conventional vehicle-mounted hydraulic system will be described with reference to FIG. In the figure, 1 is a reservoir tank, 2 is a double pump that applies oil pressure to the oil sent from the reservoir tank, and 3 is an accumulator that averages the oil pressure given by the double pump 2 to make it a constant pressure. is there. Reference numeral 4 is a clutch pressure regulating valve, 5 is a hydraulic pressure sensor, and 6 is a fail-safe valve (hereinafter abbreviated as F / S valve). The clutch pressure regulating valve 4 is composed of a solenoid 4a and a valve 4b, and the F / S valve 6 is composed of a solenoid 6a and a valve 6b.

An on-vehicle ignition switch (hereinafter referred to as I
G SW) is on, the double pump 2,
The clutch pressure regulating valve 4 and the F / S valve 6 are turned on, and as shown in the figure, the hydraulic pressure applied by the dual pump 2 is made constant by the accumulator 3, and the clutch pressure regulating valve 4 Is supplied to the clutch via. At this time, the oil pressure sensor 5 measures the oil pressure supplied to the clutch.

The drain of the hydraulic pressure supplied to the clutch is sent to the F / S valve 6 through the orifice of the valve 4b, and is further returned to the reservoir tank 1.

Now, when the IG SW is turned off, as shown in FIG. 6, the clutch pressure regulating valve 4 and the F / S valve 6 are turned off, and the hydraulic circuit shown in the figure is opened. Form. The output of the oil pressure sensor 5 at this time has a waveform as shown in FIG.

In FIG. 7, t1 shows the time when the IG SW is turned off, and t3 shows the time when the hydraulic sensor 5 measures the peak value. The output of the hydraulic pressure sensor 5 rises at the times t1 to t3 because the hydraulic pressure stored in the accumulator 3 is temporarily released. The reason why the hydraulic pressure decreases after the time point t3 is that the drain gradually escapes through the orifice of the valve 6b.

[0007]

In the above-described vehicle-mounted hydraulic system, the clutch pressure regulating valve 4 and the F / S valve 6 ensure control continuity while the IG SW is on. In order to do that, there was the problem that it could not be turned off.

In the above description, the problem of the prior art is explained by taking the vehicle-mounted hydraulic system as an example, but the actuator is turned off in order to ensure continuity of control during operation, not limited to the vehicle-mounted hydraulic system. In such a system, it is difficult to make a failure diagnosis of the actuator.

An object of the present invention is to eliminate the above-mentioned problems of the prior art and to diagnose a failure of an actuator which cannot be turned off in order to ensure continuity of control during operation, and more particularly to a vehicle-mounted hydraulic circuit. An object of the present invention is to provide a failure detection device for an internal hydraulic control valve.

[0010]

In order to achieve the above object, the present invention is a failure detecting device for an actuator which is turned off when a power source SW is turned off, and detects a physical change caused by the operation of the actuator. After the sensor and the power supply SW are turned off, the power supply of another system is kept on and the output of the sensor is monitored for a predetermined time.
It is characterized in that it comprises means for comparing the output signal with a predetermined threshold value.

[0011]

According to the present invention, after the power source SW is turned off,
Since the output signal of the sensor is monitored by keeping the power supply of another system on for a predetermined time, the actuator cannot be turned off to ensure continuity of control during operation. System actuator failures can be diagnosed.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. FIG. 1 is a control block diagram of a hydraulic system according to an embodiment of the present invention, in which 11 is a battery, 12 is an IGSW,
Reference numeral 13 indicates a control unit. 21 is CP
U and 22 are main power supplies, 23 is a sub power supply, 24-27 are transistors, and 28 is a diode. Other signs are
The same as or equivalent to FIG. 5 is shown.

The structure and operation of the clutch pressure regulating valve 4 and the F / S valve 6 will now be described with reference to FIGS. 2 and 3. FIGS. 2 (a) and 2 (b) show the operation of the clutch pressure regulating valve 4 and the F / S valve 6 when they are turned on, and FIGS. 3 (a) and 3 (b) show the clutch pressure regulating valve 4 respectively. Also, the operation when the F / S valve 6 is off is shown.

When the clutch pressure regulating valve 4 is turned on,
As shown in FIG. 2 (a), the hydraulic pressure from the accumulator 3 is transmitted to the clutch, and the drain is sent to the F / S valve 6 via the orifice. When the F / S valve 6 is turned on, the drain is connected to the reservoir tank 1
Have returned to.

Further, when the clutch pressure regulating valve 4 is off, the F / S valve 6 is provided as shown in FIG. 3 (a).
Supply the hydraulic pressure from the to the clutch. When the F / S valve 6 is off, the hydraulic pressure from the accumulator 3 is sent to the clutch pressure regulating valve 4, and the drain is returned to the reservoir tank 1.

The clutch pressure regulating valve 4 and the F / S valve 6 normally operate as described above, but if they fail, they will not operate as described above.

FIG. 1 is a circuit for diagnosing a failure of the hydraulic control valve that operates as described above, and FIG. 4 is a waveform diagram of signals at corresponding points in FIG.

The operation of this embodiment will be described below with reference to FIGS. When IGSW12 is on (at H level), ignition voltage IG1 equal to the battery voltage is applied to the emitter of transistor 25. The base of the transistor 25 is connected to the L from the CPU 21.
Since the level signal is applied and the transistor 25 is turned on, a voltage of, for example, 12 V is applied to the clutch pressure regulating valve 4 and the F / S valve 6. As a result, the clutch pressure regulating valve 4 and the F / S valve 6 are turned on, and the illustrated hydraulic circuit is configured.

The transistor 24 is on and the signal is at L level. The input signal from the oil pressure sensor 5 is at the level shown, and the signal is at the L level. When the signal is at L level,
Transistor 26 turns on and transistor 27 turns on. Therefore, the battery voltage is supplied to the main power source 22, and the main power source 22 supplies a predetermined voltage, for example, 5V.
Occurs. This main power supply voltage is
It is connected to 1.

On the other hand, the sub power source 23 is always connected to the battery 11 and serves as a backup power source for the CPU 21. The diode 28 has a function of immediately starting up the main power source 22 when the IG SW 12 is turned on.

Now, at time t1, IG SW12
When is turned off, self-diagnosis of the clutch pressure regulating valve 4 and the F / S valve 6 is started. IG SW1
When 2 is turned off, the voltage becomes 0 V, and the clutch pressure regulating valve 4 and the F / S valve 6 are turned off.

At this time, if the clutch pressure regulating valve 4 and the F / S valve 6 are normal, the output waveform of the hydraulic pressure sensor 5 becomes as shown in the following, and it rapidly rises from the time t1 and at the time t2 (however, , T1 to t2 are within 500 ms)
The predetermined threshold value th is exceeded. However, if one or both of the clutch pressure regulating valve 4 and the F / S valve 6 are out of order, the output waveform of the hydraulic pressure sensor 5 becomes as shown by ‘t1 to t2.
The threshold value th will not be exceeded within a time.

Therefore, when the output waveform of the hydraulic pressure sensor 5 exceeds the threshold value th within 500 msec, the CPU 21
If it is judged that the clutch pressure regulating valve 4 and the F / S valve 6 are normal, and the output waveform of the hydraulic pressure sensor 5 does not exceed the threshold value th within 500 msec, the clutch pressure regulating valve 4 and the F / S valve 6 It is determined that the valve 6 is out of order, and the result is stored in a memory (not shown) connected to the CPU 21. Alternatively, the failure is displayed on a display device (not shown). Alternatively, an alarm sound to that effect is generated.

At time t2, the CPU 21 completes the self-diagnosis, sets the signal to the H level, and turns on the main power supply 2
Turn off 2. As a result, the main power supply voltage drops to the L level, the CPU 21 enters the stop mode, and shifts to the low power consumption mode. The sub power supply 23 is
It is at the H level regardless of whether the GSW 12 is on or off, and serves as a backup power source for data to be protected in the CPU 21.

As is apparent from the above description, according to this embodiment, the output of the hydraulic pressure sensor 5 is monitored for about 500 msec after the IG SW is turned off. And, the failure diagnosis of the F / S valve 6 can be performed. Further, after the failure diagnosis, the main power supply is immediately stopped and the mode is shifted to the low power consumption mode, so that the power can be saved.

In the above embodiment, the vehicle-mounted hydraulic system has been described as an example for the sake of clarity. However, the present invention is not limited to this, and control continuity is ensured during operation. Therefore, in a system including an actuator in which failure diagnosis is difficult, if the physical quantity that changes when the operation of the actuator is off, such as distance, angle, force, pressure, speed, voltage, or current, is detected, the present invention is
Obviously, it can also be applied to failure diagnosis of the actuator.

[0027]

According to the present invention, after the power source SW is turned off, the power source of another system is not turned off immediately but kept on for a predetermined time to perform self-diagnosis of the actuator. There is an effect that failure diagnosis of an actuator of a system including an actuator that cannot be turned off in order to ensure continuity of control during operation can be performed.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an operation when a hydraulic control valve is turned on.

FIG. 3 is a cross-sectional view showing an operation of the hydraulic control valve when it is off.

FIG. 4 is a waveform diagram of signals of main parts of the circuit of FIG.

FIG. 5 is a circuit diagram showing a vehicle-mounted hydraulic circuit when turned on.

FIG. 6 is a circuit diagram showing a vehicle-mounted hydraulic circuit when turned off.

FIG. 7 is a waveform diagram output by the oil pressure sensor when the oil pressure control valve is normal.

[Explanation of symbols]

1 ... Reservoir tank, 2 ... 2 pumps, 3 ... Accumulator, 4 ... Clutch pressure regulating valve, 5 ... Hydraulic pressure sensor, 6
... F / S valve, 11 ... Battery, 12 ... Ignition switch (IG SW), 13 ... Control unit, 21 ... CPU, 22 ... Main power supply, 23 ... Sub power supply

Claims (7)

[Claims] 1. A failure detection device for an actuator that is turned off when the power supply SW is turned off, the sensor detecting a physical change caused by the operation of the actuator, and a separate system after the power supply SW is turned off. Means for holding the power supply of the sensor in the ON state, monitoring the output of the sensor for a predetermined time, and comparing the output signal with a predetermined threshold value, and detecting a failure of the actuator based on the comparison result. An actuator failure detection device characterized by the above. 2. After the detection of the failure, after turning off the power supply of the different system, or after turning off the power supply of the different system,
The mode is changed to a low power consumption mode.
Failure detection device for the actuator described. 3. The power source SW is an ignition switch (IG SW) of a vehicle.
Failure detection device for the actuator described. 4. The actuator failure detection device according to claim 1, wherein the actuator is a hydraulic control valve. 5. The actuator failure detection device according to claim 1, wherein the sensor is a hydraulic pressure sensor. 6. The actuator failure detection device according to claim 1, wherein the predetermined time is about 500 milliseconds. 7. The hydraulic pressure sensor is provided downstream of the hydraulic pressure control valve.
The actuator failure detection device according to [1].