JPS59126830A - Measurer for leak amount of oil-pressure device - Google Patents

Abstract

PURPOSE:To exactly measure the amount of leak in chamber by combining a circuit to measure the amount of leak in an oil supplier for oil-pressure cylinder, etc., a centralized controller, a vehicle number receiver, an input pendant and an oil-pressure device. CONSTITUTION:A measurer for the amount of leak in oil-pressure devices is comosed of a displayer 5 to display operating procedure by outputs from a centralized controller 1, an oil-pressure device 6 to supply a given pressure oil to the cylinders 2 of bucket, arm and boom on the basis of command of the centralized controller 1, a measuring circuit 9 to measure the oil pressure of the cylinder 2, an arithmetical circuit 10 to compare the output of the circuit 9 with the output of a memory circuit 11 in which reference oil pressure is stored, a pendant 4 to put operating procedure corresponding to the specimen cylinder 2 into the centralized controller 1, and a vehicle species and number receiver to supply comparison signal of test oil pressure value signal, operating procedure displayer signal, and reference value to the centralized controller 1.

Description

[Detailed description of the invention] The present invention relates to a leak measurement device for a hydraulic system.

・Internal leaks from hydraulic equipment such as shovels and construction machinery vary depending on the oil used, pressure, and temperature.
Changes in the oil used over time (abrasion deterioration, etc.) promote leaks. The same can be said of internal leaks in the piping system of newly manufactured hydraulic equipment. Such leakage causes problems in operation. For example, if an internal leak occurs in the hydraulic system of a power excavator, the specified output will not be sufficient, which will significantly reduce work efficiency, and the movement of packets and arms will become unnatural, which can be dangerous. That's what happens. Seventh and final, it was necessary to strictly conduct leak tests during inspections and periodic inspections and maintenance before product shipment. This horizontal placement method either measures the movement of the packet, boom, and arms by reproducing actual operating conditions, or measures a stand on which the packet, boom, and arms naturally lower due to their own weight. Ta. Therefore, in the leak test of each movable part of the front part of a power excavator, that is, the packet, boom, and arm, it is necessary to simultaneously measure the load, 9 hours of travel time, oil pressure, and oil temperature. They needed experienced workers.

The present invention has been made in view of the above points, and it is easy to operate, eliminates the need for skilled personnel, and allows easy lifting and lowering. The present invention provides a leak meter measuring device for a hydraulic system that can accurately measure 1 (+1 constant) indoors.

That is, the present invention provides a display device for displaying the cutting procedure based on an output from a central control device, a hydraulic device for supplying a predetermined hydraulic pressure to a test machine based on commands from the central control device, and a measuring circuit for measuring the oil pressure of the machine; an arithmetic circuit for comparing the output of the measuring circuit with the output of a reference value storage circuit that stores the base oil pressure in advance; a pendant that supplies the central control device with a work procedure signal corresponding to the test machine; and a pendant that supplies the central control device with a test oil pressure value Q'31'', an operation procedure display signal and a reference value corresponding to the test machine. This is a leak amount measuring device for a hydraulic device 6, which is equipped with a vehicle type number receiving device that supplies a comparison signal.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory diagram showing a schematic configuration of an embodiment of the present invention. 1 in the figure is a central control unit CPU. The central controller IK is supplied with signals from a vehicle model number receiving device 3 that receives the model number of the test machine 2 and a pendant 4 that is equipped with a push button switch that advances the work. The central control device I is configured to output predetermined signals to the display device 5 and the hydraulic device 6. The display device 5 has a function of displaying work order 1 work instructions and results.

The hydraulic system 6 is configured to supply test hydraulic pressure to the test machine 2 via a measuring cylinder 7 that measures the amount of leakage.

The oil temperatures of the test machine 2 and the hydraulic system 6 are monitored by an oil temperature sensor 8. The outputs of the oil temperature sensor 8 and the measuring cylinder 7 are supplied to a measuring circuit 9 for processing. An arithmetic circuit 10 is connected to the measurement circuit 9, which uses the signal processed by the measurement circuit 9 as a measured value.

The arithmetic circuit 10 contains pressure setting standard values sorted by vehicle model number, standard values 2 for determining pass/fail of measurement results, and work order 2.
A reference value storage circuit 11 for stocking displays and the like is connected. Measuring circuit 9° Arithmetic circuit 10. Predetermined signals are supplied to each other between the reference value storage circuit 11 and the central control device 1.

Further, the hydraulic device 6 and the metering cylinder 7 constitute a metering hydraulic device 20 shown in FIG. FIG. 21 shows an oil tank for metering.

The oil tank 21 has an oil level gauge 22 with a temperature gauge. Level switch 23. A thermoswitch 24 is attached. The level switch 23 is an oil contact monitoring switch, and when the oil level drops below a specified level, the electric motor 25, which will be described later, is
stop. The thermoswitch 24I''i is a temperature monitoring switch for the hydraulic oil, and normally has an upper limit of 60°C, and stops the electric motor 25 when the temperature exceeds 60°C.

Further, a magnet 26 is provided inside the oil tank 21. The magnet 26 is designed to attract iron powder on the oil surface and prevent each hydraulic device from being worn out. The oil in the oil tank 21 is passed through the tank filter 27 to the tank f2B.
is being supplied to. The pump 28 has the function of generating a predetermined hydraulic pressure and supplying oil.

An electric motor 25 for driving the bomb f2B is connected to the bomb f2B. The pump 28 and the electric motor 25 are connected by a shaft joint 29. A check valve 30 for preventing backflow of discharged oil is attached to the outlet of the pump 28. The pump 28 is connected to electromagnetic valves 32a, 32b, 92c via an oil pipe 31 in front of the check valve 30.

A flow regulator 33 is installed between the check valve 30 and the solenoid valve 32a of the oil pipe 31. The flow regulator 33 is for adjusting the flow rate of the gauging oil circuit. A measuring cylinder 35 is attached to the solenoid valve 32m via an oil pipe 34. An electromagnetic scale 36 is connected to the measuring cylinder 35 . J-1 to oil pipe 34
A check valve 37 is installed. Measuring cylinder 35
is designed to set the test maximum flow rate. The electromagnetic scale 36 has a function of measuring the amount of oil, and is configured to supply a pulse signal corresponding to the measured amount to the measuring circuit 9. Check valve 3o and flow regulator 33
In the oil pipe 31 between, there are three oil pipes, 71a, 3
lb, ? 1 c is branched. One of the oil amounts '7431 a td, 'tW, magnetic valves 32b, 3
Connected to 2c. A pressure pipe 38 is attached to the other oil pipe 31b. One remaining amount of oil 'Jjf
31 c K is a relief valve 39 and an electromagnetic relief valve 4
0 is attached, and the tip of the oil pipe 31c is connected to another oil pipe 41.

The IJ leaf valve 39 and the IJ leaf valve 4o receive a signal set by the central control, and
It is designed to set the specified oil pressure. One 1'1f part of the oil pipe 4 is connected to an oil pipe 42 piped between the three electromagnetic valves 32a-32e, and the other end communicates with the inside of the oil tank 2. A return filter 43 is attached to the oil pipe 41 to filter nine return shafts.

Further, the electromagnetic valve 32h is a switching valve that switches the operation of the metering cylinder 35, and operates according to a command from the central controller 10. The switching operation of the electromagnetic valve 32b is such that when the reverse side is excited, oil is supplied into the cylinder and the cylinder is ready for measurement. On the other hand, for excitation on the forward side, a specified pressure is applied to the oil in the cylinder, and the test machine 2
The measurement is performed after the points up to the inlets of the pilot check valves 44th, 44b, and 44c corresponding to the measurement points A, B, and C have the same pressure. Hydraulic pressure supply to the test machine is A.

This is done for B and C individually, and oil supply to a desired location, for example C, is started by operating the solenoid valve 32c.

45a, 45b, and 45c are valves for preventing backflow from the test device 2, and 46 is a pressure gauge for measuring the pressure inside the piping.

Next, the operation of the metering hydraulic system configured as described above will be explained based on an actual example of a hydraulic circuit leak test for a power shovel, boom, arm, and packet. First, the model of the power shovel is input into the East German number acceptance device 3. Next, the engine data extracts the specified oil pressure for testing from the reference value storage circuit 11 via the central controller 1.

Next, this signal is sent as a set pressure signal to the hydraulic system 6, and the signal is transmitted from the hydraulic system 6 to the electromagnetic valve 40 shown in FIG. The hydraulic system 6 operates the pump 28 before receiving the set pressure signal, and simultaneously operates the electromagnetic relief valve 40.
Waits for a command to supply oil to the test machine 2 at a specified pressure.

On the other hand, the central control device 1 calls up the work order 1 work instruction from the reference value storage circuit 1 and displays a predetermined display using the display device 5, that is, a cathode ray tube or the like. The subsequent work progresses in sequence by pressing the switches on the pendant 4 in accordance with the instructions displayed on the cathode ray tube. Here, the oil supply hose to the test machine 2 is connected with a cover (hose coupling fitting), and at the same time, the test support oil temperature sensor 8 is attached to complete preparations.

Next, before testing the test machine 2, an internal leak test of the hydraulic circuit 9 of the metering cylinder 7 is performed. Excite the forward side of the solenoid valve 32a (reference: forward side - measurement, backward side - replenishment of measuring oil to the measuring cylinder) by the electromagnetic IJ IJ-f valve 40.
The set specified oil pressure is supplied to the forward side of the metering cylinder 35. At this time, all circuits to the test machine 2 are closed. Thereby a check valve 37- containing a metering cylinder 7.

Leakage from the pilot check valves 44a...44c and their piping is detected by the electromagnetic scale 36, and L2 (cc/min) is calculated by the measurement and calculation circuits 9 and 10. When the metering cylinder, hydraulic circuit 9, and internal leak tests are completed, the work instructions on the cathode ray tube indicate the start of testing of the test machine 2, and the pendant 4 is pressed accordingly. Solenoid valve 32b
The A circuit is energized, the flat pilot check valve 44a is opened, and the specified hydraulic pressure is supplied to the A circuit (for boom circuit leak test of arm excavator). This is the beginning of the measured quantity. The measurement start time is 6 seconds after the solenoid valve 32b is activated, taking into account the expansion of the piping system including the test machine (6 seconds is set empirically based on various experiments). value). When one minute has elapsed from the start of the measurement (the measurement time can be changed arbitrarily), the circuit automatically switches to the next eight circuits and sequentially proceeds in the same measurement order as the circuit. Naturally, the oil temperature during the test is constantly monitored by the oil temperature sensor 8, and changes in oil viscosity due to temperature changes are measured using a correction coefficient 82.
(measurement system oil temperature correction system) and Sl (test machine system oil temperature correction system) are multiplied by the leak value to obtain the true value (value for a constant oil temperature). However, for excavators where there is no noticeable change in oil temperature, the oil temperature at the time of the test must be specified (approximately 50°C in the case of excavators), and the oil temperature should be corrected if the measurement is performed when that temperature is reached. It is not necessary to do this. As with the internal leak test, the leak amount measurement is performed by detecting the movement of the rod of the measuring cylinder 35 with the electromagnetic scale 36,
Measurement and performance L 1 (cc/min) in 4 circuits 10
Calculate.

The amount of leakage from the test device 2 to be determined is determined by equation (1) or (2), and the calculated value is displayed on the display device 5.
(CRT and Glinter), and at the same time, it is compared with the specified leakage amount in the reference value storage circuit 11, and a pass/fail determination is also displayed.

The table below shows the open/close states of the solenoid valves.

As shown in the table, according to this leakage measuring device for hydraulic equipment,
It has the following effects.

■ The test machine is stationary indoors without moving or running.
Tests similar to those in operation can be performed. By the way,
For example, in the test of 10 meters x 11
It can be stored within a 110 m (110 m) installation area, and is free from adverse conditions such as outdoor wind and rain and sludge buildup from driving.

■ In the past, testing required at least two operators. However, according to this device, only one operator can judge the measurement results and pass/fail. The measurement data is free from errors due to individual differences.

■ The operator can operate the device according to the instructions displayed on the CRT (cathode ray tube), etc., according to the instructions from the CPU, and the device will automatically take measurements. Freed from tedious work. Further, since the operation is easy, the operation does not need to be performed by a skilled person.

As described above, according to the leakage measuring device for a hydraulic system according to the present invention, the leakage amount can be measured indoors and accurately with simple operation and without the need for a skilled person.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing a schematic configuration of a hydraulic control system. DESCRIPTION OF SYMBOLS 1... Central control device, 2... Test machine, 3... Vehicle model number acceptance device, 4... 4 danto, 5... Display device, 6... Hydraulic system, 7... Measuring cylinder, 8...
Oil temperature sensor, 9...Measuring circuit, 10...Arithmetic circuit,
11... Reference value storage circuit, 20... Leak amount measuring device for hydraulic system.

Claims (1)

[Claims] A display device that displays work procedures based on output from a central control device, a hydraulic device that supplies a predetermined hydraulic pressure to the test machine based on commands from the central control device, and a measurement circuit that measures the hydraulic pressure of the test machine. an arithmetic circuit that performs a comparison between the output of the measuring circuit and the output of a reference value storage circuit that stores a reference oil pressure in advance based on a command from the central controller; a vehicle 41t that supplies a test oil pressure value 4G hawk corresponding to the test machine to the central control device; 1. A leak amount measuring device for a hydraulic system, characterized by comprising a No. LR receiving device.