JP2750586B2 - Reducing valve characteristic test equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure reducing valve characteristic test apparatus for automatically testing various characteristics of a pressure reducing valve used as a pressure reducing valve type pilot valve or the like.

[Conventional technology]

Generally, various cylinders provided on the front of a hydraulic shovel, left and right traveling hydraulic motors, and the like are controlled by operating an operation lever in a cab. Therefore, the pilot valve is operated by the operating lever, the switching valve in the main hydraulic circuit is controlled by the pilot pressure from the pilot valve, and the various cylinders and the traveling hydraulic motor are controlled by the switching of the pressure oil by the switching valve. It has become.

Therefore, a hydraulic circuit for actuator control using a pressure-reducing valve type pilot valve operated by an operation lever is conventionally configured as shown in FIG.

In FIG. 5, 101 and 102 are main pipes. One ends of the main pipes 101 and 102 are connected to a main hydraulic pump 103 and a tank 104, and a four-port three-position hydraulic pilot type switching valve 105 is provided in the middle thereof. The other ends of the pipes 101 and 102 are connected to an actuator (not shown).

Reference numeral 106 denotes a pressure reducing valve type pilot valve. The pilot valve 106 includes an operating lever 107 and a pair of pressure reducing valves 108 and 109 operated by the operating lever 107. Each of the pressure reducing valves 108 and 109 is provided with a spool type valve body 108A, 109A and a pusher 10 for displacing the valve bodies 108A, 109A by the operation force of the operation lever 107.
8B, 109B and springs 108C, 109 for returning the pushers 108B, 109B.
C, pressure setting springs 108D and 109D, and pressure receiving units 108E and 109E for feeding back the generated pilot pressure.

Further, the pump ports P of the pressure reducing valves 108 and 109 are connected to the pilot hydraulic pump 110, and the tank port T is connected to the tank 1
04, and the actuator port A is connected to the hydraulic pilot sections 105A, 1A of the switching valve 105 through the pilot pipes 111, 112.
Connected to 05B.

In the hydraulic circuit thus configured, the operation lever
By operating 107, a pilot pressure proportional to the operation amount is generated from pressure reducing valves 108 and 109. Then, the pilot pressure is supplied to the switching valve 105 to control the switching of the switching valve 105, thereby switching the main pipes 101 and 102 to operate the actuator.

However, since the pressure reducing valves 108 and 109 generate a pilot pressure corresponding to the displacement amount, the characteristics of the pressure reducing valves need to be constant in order to perform high-precision control, and the pressure reducing valves 108 and 109 are strict. A characteristic test is being performed.

For this reason, the characteristic test apparatus of the pressure reducing valve according to the prior art
A test table equipped with a manually operated push rod, a pump pipe for connecting a pump port of a pressure reducing valve fixed to the test table to a constant pressure pump, a tank pipe for connecting a tank port to a tank, and the actuator port side. A pressure gauge that detects an actuator port side pressure as a generated pilot pressure, a displacement gauge that detects a displacement of a manually operated push rod,
X- which records the pressure detected by the pressure gauge and the displacement of the pressing rod
And a Y pen recorder.

Then, to test the pressure reducing valve, the pressure reducing valve is fixed to a test table and connected to each pipe, and then a pressing rod is pressed against a pusher of the pressure reducing valve, and then the pressing rod is moved at a constant speed until the stroke end. Pushing is performed, and the pressing rod is operated to return at a constant speed. At this time, the pilot pressure generated in the pressure reducing valve is detected by the pressure gauge, and the displacement of the manually operated push rod is detected by the displacement gauge and recorded on the XY pen recorder.

Thus, the diagram recorded on the XY pen recorder was visually observed, the performance was evaluated, and the pass or fail was comprehensively determined.

[Problems to be solved by the invention]

However, in the above-mentioned prior art, the pushing operation of the pusher is manually performed using a pushing rod, and the X-
Comprehensive judgment is made visually from a diagram recorded on a Y pen recorder, and has the drawback that the operation requires skill and individual judgment tends to occur.

Further, the XY pen recorder has a drawback that the workability is inferior because the recording paper must be set one by one for each inspection, and the position of the pen must be adjusted to the origin of the recording paper. .

The present invention has been made in view of such a drawback of the related art, and a series of test operations is automatically performed, and a performance is automatically determined based on test results. It is an object to provide a characteristic test device.

[Means for solving the problem]

In order to achieve the above object, the present invention has a pump port, a tank port and an actuator port,
A pressure source for supplying a constant pressure oil to a pump port of the pressure reducing valve, a block means for sealing the actuator port side, and the blocking means. Pressure detecting means for detecting an actuator port side pressure sealed by the actuator, an actuator for applying a load as an operating force to the pressure reducing valve, displacement detecting means for detecting displacement of the actuator, and operation of the pressure reducing valve by the actuator Zero setting detecting means for detecting a start position as a zero setting position, and detection signals from the pressure detecting means, displacement detecting means and zero setting detecting means are inputted, and the actuator operates to set the zero setting detecting means to the zero setting position. Is detected, the characteristics of the pressure reducing valve are determined based on the detection signals from the pressure detecting means and the displacement detecting means. Characterized by being composed of a constant section.

[Action]

With this configuration, if the actuator is operated, the determination unit includes a pressure detection unit, a displacement detection unit,
The signal from the zero setting detecting means is input, and the characteristic data of the pressure reducing valve is stored, and can be visually observed on a printer, a CRT display, or the like as necessary. Then, the determination means performs a performance evaluation based on a previously stored determination criterion, and automatically determines suitability.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 4.

First, in FIG. 1, reference numeral 1 denotes a pressure reducing valve to be tested. The pressure reducing valve 1 has a valve body 1A having a pump port P, a tank port T, and an actuator port A, and a hydraulic cylinder 21 described later as an operating force. A pusher 1B to which a load is applied, a spring 1C for returning the pusher 1B, a spring 1D for setting the pressure, and a pressure receiving portion 1E for receiving the generated pilot pressure.
It is composed of

2 is an electric motor, 3 and 4 are hydraulic pumps operated by the electric motor 2, one hydraulic pump 3 is a hydraulic pump for supplying pressure oil to the pressure reducing valve 1, and 4 is a hydraulic pump for supplying pressure oil to the hydraulic cylinder 21. It is a pump. 5 and 6 are pump pipes connecting between the hydraulic pump 3 and the pump port P of the pressure reducing valve 1.
In order to switch between the pump pipes 5, 6 and an actuator pipe 17 and a tank pipe 18, which will be described later, a 4-port 3-position non-leak solenoid valve 7 having a neutral position (a), a switching position (b) and (c). A relief valve 8 for controlling the discharge pressure of the hydraulic pump 3 to a predetermined constant pressure is provided on the pump pipe 5 side.
Is provided, and a pressure gauge 9 for detecting the internal pressure thereof is provided on the pump pipe 6 side.

Reference numerals 10, 11, and 12 denote tank pipes connecting the tank port T of the pressure reducing valve 1 to the tank 13, and switch positions (a) for selectively switching the tank pipe 10 to the tank pipes 11 and 12 on the way.
A four-port, three-position solenoid valve 14 having (b) is provided. The tank pipe 11 is provided with a flow meter 15 for measuring the flow rate flowing inside, and the tank pipe 12 is provided with a pressure gauge 16 for detecting the internal pressure.

Reference numeral 17 denotes an actuator pipe connecting the actuator port A of the pressure reducing valve 1 to the other surface of the solenoid valve 7, and reference numeral 18 denotes a tank pipe connecting the one surface of the solenoid valve 7 to the tank 13. the internal pressure P _a middle block position (a) and communicating position (b) and two-port two-position of the non-leak type solenoid valve 19 having are provided, also located in the actuator port a side of the solenoid valve 19 Is provided, and is connected to the pressure receiving section 1E of the pressure reducing valve 1. Here, the solenoid valve 19 is a specific example of the blocking means according to the present invention, and the pressure gauge 20 is a specific example of the pressure detecting means according to the present invention.

Next, 21 is a hydraulic cylinder that applies a load as an operating force to the pusher 1B of the pressure reducing valve 1. The hydraulic cylinder 21 is a cylinder 21A, a piston 21B slidably provided in the cylinder 21A, and a piston 21B. Fixed to 21B and cylinder
And a piston rod 21C penetrating both ends of 21A.

Reference numeral 22 denotes a displacement meter as displacement detection means for detecting a piston stroke of the hydraulic cylinder 21. The displacement meter 22 is mounted above the piston rod 21C, for example, a potentiometer or the like is applied.

Reference numeral 23 denotes a load meter as a zero setting detecting means for detecting a load applied to the pusher 1B of the pressure reducing valve 1 by the hydraulic cylinder 21. The load meter 23 is mounted below the piston rod 21C. The pressing member also presses the pusher 1B according to the piston stroke. Here, the load meter 23 is lowered and abuts on the pusher 1B, and detects the time when the detected load is not just zero as the operation start time of the pusher 1B, that is, the zero set position or the origin position of the pilot pressure characteristic detection. It has a zero setting detection function and a load detection function for detecting a load applied to the pusher 1B.

Reference numeral 24 denotes a four-port three-position solenoid valve having a neutral position (a) and switching positions (b) and (c) for switching hydraulic oil to the hydraulic cylinder 21. A pump pipe 25 connected to the pump 4 and a tank pipe 26 connected to the tank 13 are provided.
Supply and discharge pipes 27 and 28 for supplying and discharging pressure oil to and from each of the oil chambers are provided. In the middle of the supply and discharge pipes 27 and 28, pilot-type check valves 29 and 3 that are opened by a pilot signal are provided.
0, speed adjusting valves 31 and 32 are provided.

FIG. 2 is a block diagram showing the overall configuration of the signal system. In the figure, reference numeral 33 denotes a control device constituted by, for example, a microcomputer or the like. The input side of the control device 33 has an analog-digital (A / D) signal. Pressure gauge 9,1 via converter 34
6, 20, a displacement meter 22, a load meter 23, and a flow meter 15 are connected. The output side is connected to solenoid valves 7, 14, 19, and 24, and the characteristic diagram shown in FIG. Printer to print out
35, a CRT display 36 for displaying the same items as the printer 35, and the like. A program shown in FIG. 3 is stored in a storage area (for example, in ROM) of the control device 33, and a test operation and a result determination are automatically performed by a test process described later.

The present embodiment is configured as described above. Next, the test processing operation will be described with reference to FIG.

First, as a preparatory work, the pressure reducing valve 1 to be tested is fixed on a test table (not shown), and the pump port 6 has a pump pipe 6, the tank port T has a tank pipe 10, and the actuator port A has an actuator pipe. Connect 17 each.

In this state, when the process is started, in step 1, the solenoid valve 7 is switched to the switching position (c), the solenoid valve 14 is switched to the switching position (b), and the solenoid valve 19 is set to the communication position (b) under the control of the control device 33. Switch. As a result, the pressure oil from the hydraulic pump 3 maintained at a constant pressure by the relief valve 8 is supplied to the pump pipe 5, the solenoid valve 7,
The pressure is supplied to the actuator port A of the pressure reducing valve 1 via the actuator pipe 17 and the solenoid valve 19. At this time, the hydraulic cylinder 21 is not yet operated, and the pressure reducing valve 1 is in communication between the actuator port A and the tank port T. It is discharged to the tank 13 via the solenoid valve 14 and the tank pipe 12.

Therefore, the first test data, since the pressure reducing valve 1 is to measure the pressure drop [Delta] P _AT between the actuator port A and the tank port T of the inoperative, the pressure in the next step 2 meter 2
Detecting the pressure in each pipe 17 and 12 with 0, 16, calculates the pressure drop [Delta] P _AT, memory storage area.

Next, in step 3, the solenoid valve 7 is switched to the switching position (b), the solenoid valve 14 is switched to the switching position (a), and the solenoid valve 19 is switched to the block position (a). As a result, the pressure oil from the hydraulic pump 3 is supplied to the pump port P of the pressure reducing valve 1 via the pump pipe 5, the solenoid valve 7, and the pump pipe 6. However, in this state, the pump port P and the tank port T are shut off,
No pressure oil flows out to the tank port T, and the leak amount should be zero originally.

Therefore, the tank port T is connected to the tank piping 10, the solenoid valve 14,
Connected to tank 13 via tank piping 11
11 flow meter 15 is provided, in step 4, the second test data, the flow meter 15, a leak amount Delta] Q ₁ between the pump port P and tank port T is measured and stored in memory area.

When the test in which the pressure reducing valve 1 is not operated is completed, in the next step 5, the electromagnetic valve 24 is switched to the switching position (b), and the hydraulic oil from the hydraulic pump 4 is supplied to the pump pipe 25, the electromagnetic valve 24, and the supply / discharge. The oil is supplied to the upper oil chamber of the hydraulic cylinder 21 via the pipe 27, the check valve 29, and the speed adjusting valve 31, and the hydraulic cylinder 21 is lowered.

However, between the load cell 23 provided in the hydraulic cylinder 21 and the pusher 1B of the pressure reducing valve 1, a play for an invalid stroke 1 for absorbing the variation of the model is set. Therefore, when the hydraulic cylinder 21 is lowered by the stroke l, the load meter 23 actually pushes the pusher 1B, and the load F is detected as a reaction force. Therefore, in step 6, it is monitored whether or not the detected load F of the load meter 23 has become F ≠ 0, that is, whether or not the pusher 1B has been contacted. Defined as zero setting position or origin position.

Thus, when the hydraulic cylinder 21 starts lowering, the displacement meter 22 detects the stroke,
When it is determined to be "YES", the process proceeds to the next step 7, where the stroke S of the displacement meter 22 at that time is set as the zero setting position S = Δ0, and is stored in the storage area (see FIG. 4).

However, the displacement gauge 22 detects the stroke S as the hydraulic cylinder 21 continues to descend. Also, with the solenoid valve 19 switched to the shut-off position (a),
While the pump port T of the pressure reducing valve 1 and the actuator port A gradually communicate with each other by the hydraulic cylinder 21, the pressure P _A generated on the actuator port A side, that is, the pilot pressure, is detected by the pressure gauge 20. . In step 8, the detected pressure P _A of the pressure gauge 20, for example, approximately in the middle of the pilot pressure by the pressure reducing valve _{1, P A = P AM kg} /
Monitor if cm ² (see FIG. 4) has been reached. If "YES" is determined in step 8, the process proceeds to step 9, where the solenoid valve 24 is returned to the neutral position (a), and the hydraulic cylinder 21
The supply of pressurized oil to the pump is shut off and its lowering is stopped.

In this state, the switching valve 14 is in the switching position (a) (see step 3).
The leak amount ΔQ ₂ between the pump port P and the tank port T when the detected pressure P _A of the pressure gauge 20 is P _AM kg / cm ² is detected as the third test data by 15 and stored in the memory. The leak amount ΔQ ₂ is also a return flow when the valve body 1A of the pressure reducing valve 1 is displaced to an intermediate position.

Next, when the process is performed in step 10, the process proceeds to step 11, where the solenoid valve 24 is again set to the switching position (b), and the lowering of the hydraulic cylinder 21 is restarted. Then, the control device 33 monitors the detected load F of the load meter 23, and determines that the load is a predetermined maximum load F.
When it is determined that the _{maximum value} (see FIG. 4) has been reached, the routine proceeds to step 13, where the solenoid valve 24 is switched to the neutral position (a), and the lowering of the hydraulic cylinder 21 is stopped. Therefore, the hydraulic cylinder
Until the load meter 23 reaches the maximum load _Fmax when the load meter 21 starts to descend, the displacement meter 22
Are detected as Δ0, Δ1, Δ2, Δ3, and the pressure gauge 20 detects the pressure P _A on the actuator port A side as 0, P _A1 , P _AM , P _A2 , P _A3. the the pressure P _a 4
The characteristics are as shown in the figure. In FIG. 4, Δ1 and P _A1 indicate the stroke and cracking pressure when the pressure reducing valve 1 starts opening, and Δ2 and P _A2 indicate when the proportional part of the pilot pressure rises to the maximum pressure P _A3. indicates the stroke and the rising pressure, [Delta] 3 and P _A3 represents the maximum stroke and the maximum pressure of the valve body 1A of the pressure reducing valve 1.

Thus, after stopping the hydraulic cylinder 13 at the maximum stroke position in step 13, the solenoid valve 14 is set to the switching position (b) in step 14, and the solenoid valve 19 is set to the communication position (note that the solenoid valve 7 is set in step 3). The pressure loss between the pump port P and the actuator port A during the maximum stroke is determined by the pressure gauges 9 and 20.
The _PPA is calculated and stored as fourth test data.

Furthermore, when performing calculation of pressure loss P _PA by step 15, the solenoid valve 24 to a switching position (C) proceeds to step 16, by supplying the pressure oil from the hydraulic pump 4 to the lower chamber of the hydraulic cylinder 21 The hydraulic cylinder 21 is raised. Then, in step 17, it is monitored whether or not the hydraulic cylinder 21 has reached the stroke end by the displacement meter 22 or by time management, and when it is determined that the stroke end has been reached, the solenoid valve 24 is set to the neutral position in the next step 18. Return and stop the supply of pressure oil, and set the solenoid valve 7 to the neutral position (a).
Then, the solenoid valve 19 is switched to the block position (A), and the solenoid valve 14 is switched to the switching position (A).

By the above-described processing operation, all are returned to the initial state shown in FIG. 1. However, while the hydraulic cylinder 21 makes one reciprocation, the pressure losses ΔP _AT , ΔP _PA , and the leak amounts ΔQ ₁ , ΔQ ₂ are measured. It will be memorized.

In the next step 19, the solenoid valve 7 is switched to the switching position (b) again to supply pressure oil to the pump port P of the pressure reducing valve, and the solenoid valve 24 is switched to the switching position (b), and the hydraulic cylinder 21 is moved to the upper end. To lower again. And step
In step 20, it is monitored whether or not the detected load F of the load cell 23 has become F ≠ 0. As in step 6, when it is determined to be “YES”, the zero set position or the origin position is defined. Sets the stroke S of the displacement meter 22 at this time as the zero setting position S = Δ0 and stores it.

On the other hand, by setting the solenoid valve 24 to the switching position (b) in step 19, the hydraulic cylinder 21 continues to descend. During this time, the stroke S is read by the displacement gauge 22 in step 22, and Pilot pressure
Reads the P _A, these are memory. In particular, the cracking pressure P _A1 and stroke Δ1, the specified pressure P in the proportional part
_A2, maximum pressure P _A3 and stroke Delta] 2, memory as the specific point a relationship such as maximum pressure P _A3 and maximum stroke [Delta] 3.

Then, in step 23, the detected load F from the load cell 23
Is read, and it is monitored whether or not the predetermined maximum load _Fmax has been reached in the same manner as in step 14. If "YES" is determined, the process proceeds to step 24, where the solenoid valve 24 is returned to the neutral position (A) and the hydraulic cylinder 21 is returned. Stop descending.

Next, in step 24, the solenoid valve 24 is switched to the switching position (c).
And the hydraulic cylinder 21 is raised. When it is determined in step 26 that the hydraulic cylinder 21 has reached the stroke end, the process proceeds to step 27, where the solenoid valve 24 is returned to the neutral position (a), and the hydraulic cylinder 21 is stopped. At the same time, the supply of the pressure oil to the pump port P is stopped by setting the solenoid valve 7 to the neutral position (A), and the initial state is set. During this time, the stroke S by the displacement gauge 22, pressure detected P _A by the pressure gauge 20 is a memory.

By the above steps 1 to 18 and 19 to 27, the hydraulic cylinder 21 has made two reciprocations. During this time, the respective detection data are stored in the storage area of the control device 33. Then, in the next step 28, the detected data is compared with a reference value of the pressure reducing valve 1 to be tested. That is, the strokes Δ1, Δ2,
Δ3, pressure P _A 1, P _A 2, P on the actuator port A side
_A3 3, leak amount ΔQ ₁ , ΔQ ₂ , pressure loss ΔP _AT , ΔP _PA , pressure P _A
The hysteresis H and the like at the time of rising and falling are compared with a predetermined reference value, and it is determined whether the product is acceptable (OK) or rejected (NG).

As a result, the comparison with the reference value is automatically performed for each test item described above, and the control device 33
And the characteristic diagram shown in Fig. 4 for CRT Disp. 36, OK or NG
Is output and printed out and dispressed. Therefore, the operator can know the test result from the printed out and displayed data, and can comprehensively judge and evaluate the performance from experience.

As described above, according to the present embodiment, the pressure reducing valve 1 is reciprocated two times while applying a constant operating force to the pressure reducing valve 1 using the hydraulic cylinder 21. During this time, various data necessary for the performance test are quantified and derived. The pass / fail can be automatically determined by comparing with a reference value.

In the embodiment, the non-leakage type electromagnet 19 having no internal leak is illustrated as a specific example of the blocking means.
_To exclude _AT and ΔP _PA from the test data, use solenoid valve 1
A sealing stopper may be used instead of 9.

The load cell 23 is a specific example of the zero setting detection means,
A contact sensor may be used in place of the load cell 23. In short, it is only necessary to detect the start of pressing the pusher 1B.

On the other hand, the hydraulic cylinder 21 is a representative example of an actuator that applies a load as an operating force, but may be configured by a combination of a rotary actuator such as a hydraulic motor or a stepping motor and a rotation-displacement conversion mechanism.

Further, the data for the performance test is not limited to the data of the embodiment, and other data may be added, or the data may be determined from less data or a characteristic diagram.

〔The invention's effect〕

The characteristic test device of the pressure reducing valve according to the present invention is as described in detail above, and while a constant load is applied to the pressure reducing valve by the actuator, the performance test is performed based on the displacement of the actuator and the pressure on the actuator port side. Because it was configured to automatically evaluate by detecting data and comparing it with the reference value, it was compared with the one that applies a load manually as in the prior art, eliminating variations in test results,
Further, a series of operations can be automated. On the other hand, since the operation monitoring start position is detected by the zero setting detecting means, the test can be performed regardless of the type and shape of the pressure reducing valve, and versatility can be given. Furthermore, since the actuator can be displaced at a constant speed,
The effect is obtained that the detection data is stabilized every time, and a highly accurate pressure reducing valve unmanned tester can be configured.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a specific configuration and a hydraulic circuit of a test apparatus according to the present embodiment, FIG. 2 is a block diagram showing an entire configuration of a signal system, and FIGS. 3 (a) and 3 (b) are tests. FIG. 4 is a flowchart showing the processing operation, FIG. 4 is a characteristic diagram showing the relationship between the cylinder stroke and the detected pressure, and FIG. 5 is a hydraulic circuit diagram including a pressure reducing valve type pilot valve. 1 ... Reducing valve, 3,4… Hydraulic pump, 5,6… Pump piping, 7,1
4,19,24… Solenoid valve, 9,16,20… Pressure gauge, 10,11,12,18… Tank piping, 17… Actuator piping, 21… Hydraulic cylinder, 22… Displacement gauge, 23… Load meter, 33 ... Control device, 34 ... Signal conversion device, 35 ... Printer, 36 ... CRT display.

Claims (2)

(57) [Claims] An apparatus for testing the characteristics of a pressure reducing valve having a pump port, a tank port, and an actuator port and generating a pressure corresponding to an operating force, wherein a hydraulic pressure source for supplying a constant pressure oil to the pump port of the pressure reducing valve. Block means for sealing the actuator port side, pressure detecting means for detecting pressure on the actuator port side sealed by the block means, an actuator for applying a load as an operating force to the pressure reducing valve, and the actuator Displacement detection means for detecting the displacement of the actuator, zero setting detection means for detecting the operation start position of the pressure reducing valve by the actuator as a zero setting position, and detection signals from the pressure detection means, the displacement detection means, and the zero setting detection means. Input, and after the actuator operates and the zero setting detecting means detects the zero setting position, Pressure reducing valve characteristic test apparatus according to claim based on a detection signal from the force detecting means and the displacement detecting means that is composed of a determining means for determining characteristics of the pressure reducing valve. 2. The method according to claim 1, further comprising a flow rate detection means for detecting a leak amount on a tank port side of said pressure reducing valve.
The characteristic test device of the pressure reducing valve according to the item.