JPS6313905A - Device for diagnosing abnormality in pump motor drive - Google Patents

Abstract

PURPOSE:To diagnose abnormality correctly and easily by measuring continuous drive time of a motor and judging a liquid pressure circuit as abnormal when the continuous drive time reaches a predetermined time. CONSTITUTION:A CPU 16 is provided with a timer to measure continuous drive time of a DC motor 2 to drive a pump 1. The CPU 16 judges a liquid pressure circuit is abnormal or a pressure switch 12 is in failure when the continuous drive time reaches a standard time, and the DC motor 2 is stopped. Thus abnormality in the liquid pressure circuit or failure of the pressure switch 12 can be judged more correctly and easily than by a conventional method using a thermal relay and two pressure switches.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) This invention relates to an abnormality diagnosis device for a pump motor drive device.

(Prior Art) Conventionally, for example, in an industrial vehicle equipped with an automatic transmission with a dry single-plate clutch, a hydraulic cylinder has been used as an actuator for turning the clutch on and off, or an actuator for switching the automatic transmission between forward and backward or between 1st and 2nd gears. There is. Hydraulic oil for operating this hydraulic cylinder is supplied to an accumulator by a pump, and the accumulated pressure oil is supplied to the accumulator.

On the other hand, the motor that drives the pump is driven when the pressure of the hydraulic oil falls below a predetermined pressure to supply the hydraulic oil to the accumulator. Conversely, when the hydraulic fluid reaches a predetermined pressure or higher, the motor stops driving. The Tanabata is driven and stopped by turning on and off a pressure switch provided in the hydraulic circuit.

At this time, although the pressure of the hydraulic oil exceeds a predetermined pressure and the pressure switch should be turned on from off, if the pressure switch fails and is in the off state, the motor continues to drive. Therefore, since there is a risk of damaging the pump motor or other hydraulic equipment, a safety device has been installed in the pump motor drive device.

This safety device simply installed a thermal relay or the like on the motor to automatically stop the motor when it heated up above a certain temperature, or installed two pressure switches to perform a double pressure check. .

(Problem to be Solved by the Invention) However, the thermal relay of the above-mentioned safety device can only detect abnormalities in the motor, and the adjustment work is extremely troublesome as it is necessary to adjust the activation timing depending on the difference in the environment in which it is used. It had become a thing.

Further, when double pressure checking is performed using two pressure switches, only the pressure switch can be compensated for, and since an additional pressure switch is installed in the hydraulic circuit, the mounting position becomes a problem. Moreover, even if two such devices were provided, if both failed, they would be of no use and could not be considered a safety device for fundamental safety measures.

The purpose of the present invention is to solve the above-mentioned problems by detecting the driving state of the motor that drives the pump, so that it is possible to comprehensively judge whether there is an abnormality in the fluid circuit or the pressure switch with an accurate and intermediate configuration. An object of the present invention is to provide an abnormality diagnosis device for a pump/motor drive device.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a pump that supplies pressure fluid to an accumulator, a motor that drives the pump, and a pressure horn fluid that is operated by pressure fluid stored in the accumulator. In a pump/motor drive device comprising a fluid drive means and a control means that detects the pressure of the fluid pressure and controls the drive of the motor when the pressure fluid decreases to a predetermined fluid pressure, the motor is driven or not. a detection means for detecting, a timing means for measuring the continuous driving time of the motor based on the detection signal of the detection means, and determining that there is an abnormality in the fluid circuit when the continuous driving time of the motor reaches a predetermined time. The gist of the present invention is an abnormality diagnosing device for a pump/motor drive device, which is equipped with a determining means.

(Function) When the detection means detects the drive of the motor, the timer measures the continuous drive time of the motor. The determining means determines that the motor is driven due to an abnormality in the fluid circuit when the continuous driving time of the motor measured by the clocking means reaches a predetermined time.

(Example) Hereinafter, an example in which the present invention is embodied in a hydraulic circuit of an industrial vehicle equipped with an automatic transmission with a dry single-plate clutch will be described with reference to the drawings.

FIG. 1 shows the hydraulic circuit configuration and electrical configuration for clutch drive in an industrial vehicle equipped with an automatic transmission with a dry single-plate clutch, in which a pump 1 is driven by a DC motor 2,
The hydraulic oil in the tank 3 is supplied to the accumulator 4. The hydraulic oil supplied to the accumulator 4 and stored therein is supplied from the main passage 5 to a control valve mechanism of a clutch engagement/disconnection cylinder 6 serving as a fluid drive means.

The control valve mechanism includes a high-speed input solenoid valve 7 capable of supplying the bottom side chamber 6b of the clutch engagement/disconnection cylinder 6 from the main passage 5 to the bottom side chamber 6b in 2nd speed, and a throttle section, and gradually controls the hydraulic oil from the main passage 5 to the bottom side chamber 6b. a low-speed input solenoid valve 8 capable of supplying
A high-speed output solenoid valve 9 capable of rapidly discharging the hydraulic oil in the bottom side chamber 6b to the tank 3 through the drain passage 11, and a constriction part are provided, and the hydraulic oil in the bottom side chamber 6b is gradually discharged to the tank 3 through the drain passage 11. By controlling the opening and closing of each solenoid valve 7 to 10, the bottom side chamber 6b of the clutch connection/disconnection cylinder is
Hydraulic oil can be supplied and discharged at a desired speed.

A pressure switch 12 is provided in the main passage 5 and is turned on when the pressure of the hydraulic oil in the passage falls below a predetermined pressure, and the on signal is sent via the input/output interface 13 as will be described later. Output to CPU16.

Further, the DC motor 2 is provided with a current detector 14 as a detection means for detecting the armature current, and the detection signal is outputted to the CPU 16 via the A/D converter 15 and the input/output interface 13. .

A central processing unit (hereinafter referred to as CPU) 16 serving as a control means, a timekeeping means, and a judgment means has a read-only memory (
It operates based on a control program stored in a program memory 17 (ROM). Program memory 1
The control program stored in 7 includes the pressure switch 1.
Input/output interface 1 in response to the on signal from 2.
3. 61s includes a control program for driving the DC motor 2 via the motor drive circuit 18; 1.
When the fp lightning current detector 14 detects the armature current and outputs a ≦ quasi-one signal, a timer built into the CPU 16 is activated and the DC motor 2 continues to operate while the detection signal is being output. Contains a program to measure driving time.

The control program also includes a control program that determines that there is an abnormality in the hydraulic circuit or a failure in the pressure switch 12 when the continuous driving time reaches a predetermined time (hereinafter referred to as the reference time), even if the pressure switch 12 is in the ON state. It has a program for immediately stopping the DC motor 2. Note that this reference time is such that if the hydraulic circuit is normal and the pressure switch 12 is operating normally, and the DC motor 2 is operated continuously after the pressure switch 12 is turned on, the pressure in the main passage 5 will be at the normal level. This is the time required to reach a pressure sufficient to turn off the pressure switch 12 and not to damage the hydraulic equipment in the hydraulic circuit. Exceeding this time may indicate an abnormality in the hydraulic circuit or the pressure switch 12.
This means that the pressure switch 12 will not turn off due to a failure.

The working memory 19 is a readable and rewritable memory (RAM), and is configured to temporarily store the results of calculations performed by the CPU 16 and the like. A display 20 and a speaker 21 are installed in the driver's seat, and when the CPU 16 determines that there is an abnormality in the hydraulic circuit or a failure in the pressure switch 12, the CPU
It is designed to be driven by U16.

Further, the CPU 16 appropriately selects each of the electromagnetic valves 7 to 10 via the input/output interface 13 and the valve drive circuit 22 and performs switching control (duty control in this embodiment) to reciprocate the clutch engagement/disconnection cylinder 6. to perform clutch engagement/disengagement control.

Next, the operation of the apparatus configured as described above will be explained.

Now, when the pressure switch 12 is turned on, the CPU 16 immediately drives the DC motor 2. Based on this drive, the current detector 14 detects the armature current. Based on this detection, the CPU 16 causes a built-in timer to operate to measure time.

If the pressure horn switch 12 is turned off before the continuous driving time of the DC motor 2 reaches the reference time, the CPU 11
6 resets the timer and also resets the DC motor 2.
, and the supply of hydraulic oil to the accumulator 4 is stopped.

On the other hand, if the hydraulic circuit is abnormal and the pressure of the hydraulic oil in the main passage 5 decreases and the pressure switch 12 continues to be turned on, or if the pressure switch 12 is broken and continues to be turned on,
The DC motor 2 continues to drive until the reference time is reached. When the continuous driving time reaches the reference time, the CPLJ 16 determines that the hydraulic circuit is abnormal or the pressure switch 12 is malfunctioning.

When the CPU 16 determines that there is an abnormality or failure, it immediately resets the timer, stops the DC motor 2, and stops the supply of hydraulic oil to the accumulator 4. At the same time,
The CPU 16 drives the display 2o and the speaker 21 to notify the driver.

In this way, in this embodiment, when the continuous driving time of the DC motor 2 is measured and the continuous driving time reaches the reference time, it is determined that the hydraulic circuit is abnormal or the pressure switch 12 is malfunctioning. Since the determination is made based on the actual operating time of the motor 2, abnormality in the hydraulic circuit or failure in the pressure switch 12 can be diagnosed very accurately.

In addition, as with conventional thermal relays, motor abnormalities,
In the case where only one pressure horn switch is used, it is only possible to compensate for the failure of the pressure switch, but in this embodiment, abnormalities in the hydraulic circuit can also be diagnosed.

Moreover, in this embodiment, when an abnormality or failure is determined, the DC motor 2 is stopped, so that the pump 1 and the motor 2 are not damaged, and the display 2
o and the speaker 21 to notify the driver.
The driver can reliably know about abnormalities or failures.

Note that this invention is not limited to the above embodiments,
In the embodiment described above, the current detector 14 determines whether or not the DC motor 2 is being driven, but this can be detected, for example, based on a drive command signal for the DC motor 2, or the rotation of the motor 2 or the pump 2. It may also be implemented as follows.

In addition, the reference time may be changed as appropriate, and in the above embodiment, the method was applied to a hydraulic circuit for driving a clutch in an industrial vehicle equipped with an automatic transmission with a dry single-plate clutch, but the method is not limited to this. Of course, the present invention may be applied to other hydraulic circuits as well.

Effects of the Invention As detailed above, the present invention has an excellent effect of being able to comprehensively determine abnormalities in a fluid circuit or a pressure switch with an accurate and simple configuration.

[Brief explanation of the drawing]

Fig. 1 is a hydraulic circuit and electric circuit diagram for clutch drive in an industrial vehicle equipped with an automatic transmission with a dry single-plate clutch embodying the present invention, and Fig. 2 is a flow diagram for explaining the operation of the diagnostic device. →This is a yard diagram. In the figure, 1 is a pump, 2 is a DC motor, 4 is an accumulator, 5 is a main passage, 6 is a cylinder for clutch connection/disconnection,
12 is a pressure switch, 14 is a current detector, and 16 is a central processing unit (CPU). Patent Applicant: Toyota Industries Ltd. Fujitsu Ltd.

Claims (4)

[Claims] 1. a pump that supplies pressurized fluid to an accumulator; a motor that drives the pump; a fluid drive unit operated by the pressure fluid accumulated in the accumulator; A pump/motor drive device comprising a control means for driving and controlling the motor when the pressure decreases, a detection means for detecting whether or not the motor is being driven, and a continuous drive of the motor based on a detection signal from the detection means. An abnormality diagnosing device for a pump/motor drive device, comprising a timer for measuring time and a determining means for determining an abnormality in a fluid circuit when the continuous driving time of the motor reaches a predetermined time. 2. 2. The abnormality diagnosis device for a pump/motor drive device according to claim 1, wherein the pressure fluid is hydraulic oil, and the fluid drive means is a hydraulic cylinder operated by the hydraulic oil. 3. 2. The abnormality diagnosis device for a pump/motor drive device according to claim 1, wherein the detection means is a current detector that detects the drive current of the motor. 4. 2. The abnormality diagnosis device for a pump/motor drive device according to claim 1, wherein the detection means detects whether or not the motor is being driven based on the presence or absence of a drive command signal for driving the motor.