阅读说明：本技术 电磁换向阀寿命可靠性测试液压系统 (Hydraulic system for testing service life reliability of electromagnetic directional valve ) 是由 林广� 陈东升 陈逸嘉 于 2019-12-13 设计创作，主要内容包括：本发明提供了一种电磁换向阀寿命可靠性测试液压系统,包括两组并联的测试回路和共用一个油箱的两套并联的液压动力源系统,两套液压动力源系统和两组测试回路之间设有进油球阀组,通过切换进油球阀组的不同状态可以排布三种供油形式；每套液压动力源系统均包括高压泵、电机、双路背压阀组,电机电连接高压泵,高压泵的吸油口连接于油箱,双路背压阀组的出油口连接于油箱；每组测试回路包括N个并联的被测阀,每个被测阀包括A口、B口、P口和T口,被测阀的P口连接液压动力源系统,被测阀的T口连接双路背压阀组；每个被测阀的A口和B口分别连接有压力传感器,每个被测阀的A口和B口之间还连接有位于两个压力传感器之间的测试阻尼装置。(The invention provides a hydraulic system for testing the service life reliability of an electromagnetic directional valve, which comprises two groups of parallel test loops and two groups of parallel hydraulic power source systems sharing an oil tank, wherein an oil inlet ball valve group is arranged between the two groups of hydraulic power source systems and the two groups of test loops, and three oil supply modes can be arranged by switching different states of the oil inlet ball valve group; each set of hydraulic power source system comprises a high-pressure pump, a motor and a two-way backpressure valve bank, wherein the motor is electrically connected with the high-pressure pump, an oil suction port of the high-pressure pump is connected with an oil tank, and an oil outlet of the two-way backpressure valve bank is connected with the oil tank; each group of test loops comprises N tested valves connected in parallel, each tested valve comprises an A port, a B port, a P port and a T port, the P port of each tested valve is connected with a hydraulic power source system, and the T port of each tested valve is connected with a two-way back pressure valve group; the port A and the port B of each tested valve are respectively connected with a pressure sensor, and a testing damping device positioned between the two pressure sensors is also connected between the port A and the port B of each tested valve.)

1. The utility model provides a solenoid directional valve life reliability test hydraulic system which characterized in that: the test system comprises a test loop (1) and a hydraulic power source system (2), wherein the test loop (1) comprises two groups which are connected in parallel, the hydraulic power source system (2) comprises two groups which are connected in parallel, and the two groups of hydraulic power source systems (2) share one oil tank (6); an oil inlet ball valve group (3) is arranged between the two sets of hydraulic power source systems (2) and the two sets of test loops (1), and three oil supply modes can be distributed between the two sets of hydraulic power source systems (2) and the two sets of test loops (1) by switching different states of the oil inlet ball valve group (3);

each set of hydraulic power source system (2) comprises a high-pressure pump (23), a motor (24) and a two-way back pressure valve bank (4), wherein the motor (24) is electrically connected with the high-pressure pump (23), an oil suction port of the high-pressure pump (23) is connected to an oil tank (6), and an oil outlet of the two-way back pressure valve bank (4) is connected to the oil tank (6);

each group of test circuits (1) comprises N tested valves (11) connected in parallel, each tested valve (11) comprises an A port, a B port, a P port and a T port, the P port of each tested valve (11) is connected with a hydraulic power source system (2), and the T port of each tested valve (11) is connected with a two-way back pressure valve group (4); a port A and a port B of each tested valve (11) are respectively connected with a pressure sensor (12), and a testing damping device (13) positioned between the two pressure sensors (12) is further connected between the port A and the port B of each tested valve (11).

2. The hydraulic system for testing the service life reliability of the electromagnetic directional valve according to claim 1, characterized in that: be equipped with return ball valves (5) between test circuit (1) and double-circuit backpressure valves (4), through switching the different states of return ball valves (5), two sets of three kinds of oil return modes can be arranged in test circuit (1).

3. The hydraulic system for testing the service life reliability of the electromagnetic directional valve according to claim 2, characterized in that: a butterfly valve (21) is arranged between an oil suction port of the high-pressure pump (23) and the oil tank (6), the butterfly valve (21) is connected with the oil tank (6), and a vibration-avoiding throat (22) is further arranged between the butterfly valve (21) and the oil suction port of the high-pressure pump (23).

4. The hydraulic system for testing the service life reliability of the electromagnetic directional valve according to claim 3, characterized in that: an oil outlet of the high-pressure pump (23) is connected with a pressure regulating valve group (26), and a check valve (25) is arranged between the oil outlet of the high-pressure pump (23) and the pressure regulating valve group (26).

5. The hydraulic system for testing the service life reliability of the electromagnetic directional valve according to claim 4, characterized in that: be equipped with high pressure filter (27) between pressure regulating valves (26) and oil feed ball valves (3), be equipped with one in oil feed ball valves (3) and every group test circuit (1) and be connected energy storage ware (28) with the P mouth of every tested valve (11).

6. The hydraulic system for testing the service life reliability of the electromagnetic directional valve according to any one of claims 1 to 5, characterized in that: a partition plate (7) is arranged in the oil tank (6), the oil tank (6) is divided into an oil suction area (61) and an oil return area (62) by the partition plate (7), the two sets of hydraulic power source systems (2) are connected with the oil suction area (61), and the two-way back pressure valve group (4) is connected with the oil return area (62); be equipped with filter screen (71) on baffle (7), oil tank (6) oil absorption district (61) bottom still is equipped with magnet (63).

7. The hydraulic system for testing the service life reliability of the electromagnetic directional valve according to claim 6, characterized in that: a temperature controller (81) is installed in the oil tank (6), and the temperature controller (81) is also arranged between the port P of the first tested valve (11) connected with the hydraulic power source system (2) in the two groups of test loops (1) and the corresponding energy accumulator (28); an electric heater (8) which is controlled by a temperature controller (81) in a communication way is arranged in the oil tank (6).

8. The hydraulic system for testing the service life reliability of the electromagnetic directional valve according to claim 7, characterized in that: the oil tank (6) is connected with an oil cooler (10), an outlet of the oil cooler (10) is connected with an oil return filter (101), and an oil outlet of the oil return filter (101) is connected with the oil tank (6).

9. The hydraulic system for testing the service life reliability of the electromagnetic directional valve according to claim 6, characterized in that: be equipped with level gauge (91) in oil tank (6), be equipped with in oil tank (6) with level gauge (91) communication connection's liquid level controller (9).

10. The hydraulic system for testing the service life reliability of the electromagnetic directional valve according to claim 6, characterized in that: the oil tank (6) is connected with an air filter (102).

Technical Field

The invention relates to the technical field of hydraulic test systems, in particular to a hydraulic system for testing service life reliability of an electromagnetic directional valve.

Background

With the continuous development of hydraulic technology and electromagnetic directional valve products, the service life data requirements of advanced equipment automation control on the product reliability are provided, the application of the hydraulic electromagnetic directional valve is more and more extensive, and the product reliability service life becomes the sign of the equipment advancement. At present, various domestic electromagnetic directional valves basically have no service life test data, and the element structure has the problems of unreliability and the like, and the circuit of the existing hydraulic system has the defects of high circuit working failure rate, low service life, high maintenance cost and low reliability. Therefore, a hydraulic system for testing the service life reliability of the electromagnetic directional valve needs to be designed, and the reliability and service life detection which is in accordance with the national standard of GBT35023-2018 (hydraulic component reliability assessment method) is carried out on the electromagnetic directional valve.

Disclosure of Invention

The invention aims to provide a hydraulic system for testing the service life reliability of an electromagnetic reversing valve, which can effectively detect the reliability and the service life of the electromagnetic reversing valve, and has the advantages of strong universality, strong pollution resistance and high reliability.

The technical purpose of the invention is realized by the following technical scheme:

a hydraulic system for testing service life reliability of an electromagnetic directional valve comprises a test loop and a hydraulic power source system, wherein the test loop comprises two groups which are connected in parallel, the hydraulic power source system comprises two groups which are connected in parallel, and the two groups of hydraulic power source systems share one oil tank; an oil inlet ball valve group is arranged between the two sets of hydraulic power source systems and the two sets of test loops, and three oil supply modes can be distributed between the two sets of hydraulic power source systems and the two sets of test loops by switching different states of the oil inlet ball valve group;

each set of hydraulic power source system comprises a high-pressure pump, a motor and a two-way backpressure valve bank, wherein the motor is electrically connected with the high-pressure pump, an oil suction port of the high-pressure pump is connected to an oil tank, and an oil outlet of the two-way backpressure valve bank is connected to the oil tank;

each group of test loops comprises N tested valves connected in parallel, each tested valve comprises an A port, a B port, a P port and a T port, the P port of each tested valve is connected with a hydraulic power source system, and the T port of each tested valve is connected with a two-way back pressure valve group; and the port A and the port B of each tested valve are respectively connected with a pressure sensor, and a testing damping device positioned between the two pressure sensors is also connected between the port A and the port B of each tested valve.

Through adopting above-mentioned technical scheme, two sets of hydraulic power source systems provide fluid for two sets of test circuit, switch the selection that three kinds of different fuel feeding forms were realized to the break-make condition of oil feed ball valves as required. Oil enters the P port of each tested valve from the oil inlet ball valve group and returns to the oil tank from the T port of each tested valve through the two-way back pressure valve group. The pressure of the port A and the pressure of the port B of each tested valve after the buffering action of the testing damping device are fed back through the corresponding pressure sensors, the pressure change waveform and the change number are recorded through the recorder, the service life and the reliability of the tested valve are judged through the pressure change waveform and the change number, and the standard generalization is strong, the anti-pollution capacity is strong, and the reliability is high.

Further, be equipped with return ball valves between test circuit and the double-circuit backpressure valves, through switching over return ball valves's different states, two sets of three kinds of oil return modes can be arranged to the test circuit.

Through adopting above-mentioned technical scheme, set up return ball valves and the cooperation of double-circuit backpressure valves, can switch the state of return ball valves according to the needs of in-service use, guarantee the intercommunication in fluid return circuit to guarantee the security of the normal test work and the test of test return circuit, its simple structure, the effect is obvious.

Furthermore, a butterfly valve is arranged between the oil suction port of the high-pressure pump and the oil tank, the butterfly valve is connected with the oil tank, and a vibration-avoiding throat is arranged between the butterfly valve and the oil suction port of the high-pressure pump.

Through adopting above-mentioned technical scheme, the fuel feeding can be cut off when the high-pressure pump damages in the setting of butterfly valve, avoids fluid to leak, guarantees the security. And the vibration-avoiding throat plays a good role in vibration reduction, so that the influence on the stability of an oil circuit caused by large vibration of the high-pressure pump during working is avoided.

Furthermore, an oil outlet of the high-pressure pump is connected with a pressure regulating valve group, and a check valve is arranged between the oil outlet of the high-pressure pump and the pressure regulating valve group.

Through adopting above-mentioned technical scheme, the pressure regulating valve group carries out the pressure regulating to the fluid that gets into the test circuit and handles, avoids the fluid pressure power of often testing the return circuit too high, takes place the pipe explosion easily, guarantees the normal test work of test circuit. And the setting of check valve avoids taking place fluid backward flow, but the effect is obvious for above-mentioned simple structure.

And furthermore, a high-pressure filter is arranged between the pressure regulating valve group and the oil inlet ball valve group, and an energy accumulator connected with the P port of each tested valve is arranged in the oil inlet ball valve group and each group of test loops.

Through adopting above-mentioned technical scheme, high pressure filter plays the filter action to the fluid that gets into in the test circuit, guarantees the cleanness of the fluid that gets into in the test circuit to impurity in the fluid leads to being surveyed the valve and takes place wearing and tearing and influence the test result of being surveyed the valve life-span. The accumulator can realize pressure maintaining and ensure the stability of oil pressure in the test loop.

Furthermore, a partition plate is arranged in the oil tank, the oil tank is divided into an oil suction area and an oil return area by the partition plate, the two sets of hydraulic power source systems are connected with the oil suction area, and the two-way back pressure valve bank is connected with the oil return area; the oil tank is characterized in that a filter screen is arranged on the partition plate, and a magnet is further arranged at the bottom of the oil absorption area of the oil tank.

Through adopting above-mentioned technical scheme, the oil absorption district and oil return district are cut apart into with the oil tank to the baffle, and the intercommunication of oil absorption district and oil return district fluid not only can be guaranteed in the setting of filter screen, can also filter the fluid in oil return district, avoids getting into the oil absorption district through the impurity that endless fluid carried. And the magnet that sets up in the oil absorption district can adsorb the metallic impurity in the fluid, guarantees the cleanness of oil absorption district fuel feeding.

Furthermore, a temperature controller is installed in the oil tank, and a temperature controller is also arranged between the port P of the first tested valve connected with the hydraulic power source system and the corresponding energy accumulator in the two groups of test loops; and an electric heater controlled by a temperature controller in a communication way is arranged in the oil tank.

Through adopting above-mentioned technical scheme, temperature controller and electric heater cooperation are used, and when fluid temperature was lower, electric heater heated the fluid in the oil tank, guaranteed that the temperature of fluid is normal, can satisfy the user demand in test circuit.

Furthermore, the oil tank is connected with an oil cooler, an outlet of the oil cooler is connected with an oil return filter, and an oil outlet of the oil return filter is connected with the oil tank.

Through adopting above-mentioned technical scheme, when fluid temperature was too high, the oil cold machine was cooled down the processing to fluid, carries out the control of temperature variation interval to fluid in the oil tank. And the oil return filter filters oil pollution, so that the cleanliness of the oil is improved.

Furthermore, a liquid level meter is arranged in the oil tank, and a liquid level controller in communication connection with the liquid level meter is arranged in the oil tank.

Through adopting above-mentioned technical scheme, level gauge and liquid level controller cooperation are used, guarantee that the fluid in the oil tank is sufficient, guarantee the normal test work of test circuit, and its simple structure, the effect is obvious.

Further, the oil tank is connected with an air filter.

Through adopting above-mentioned technical scheme, when the fluid in the oil tank reduces, during the air admission oil tank, air cleaner filters the impurity in to the air, avoids impurity to get into the wearing and tearing of aggravating the measured valve in being measured the valve, guarantees the reliability that is measured the valve life-span and detects.

In conclusion, the invention has the following beneficial effects:

by arranging two sets of hydraulic power source systems and two sets of test loops, the port A and the port B of each tested valve in the test loops are connected with pressure sensors, and a test damping device is connected between the port A and the port B of each tested valve. The pressure of the port A and the pressure of the port B of each tested valve after the buffering action of the testing damping device are fed back through the corresponding pressure sensors, the pressure variation waveform and the variation number are recorded through the recorder, the service life and the reliability of the tested valve are judged through the pressure variation waveform and the variation number, and the device is high in universality, strong in anti-pollution capacity and high in reliability.

Drawings

FIG. 1 is a schematic diagram of a hydraulic system for testing the service life reliability of an electromagnetic directional valve;

FIG. 2 is a schematic diagram of a hydraulic power source system in a hydraulic system for testing the service life reliability of an electromagnetic directional valve;

FIG. 3 is a schematic diagram of a test circuit in a hydraulic system for testing the service life reliability of an electromagnetic directional valve;

FIG. 4 is a schematic structural diagram of a partition plate in a hydraulic system for testing the service life reliability of an electromagnetic directional valve.

In the figure, 1, test loop; 11. a valve under test; 12. a pressure sensor; 13. testing the damping device; 2. a hydraulic power source system; 21. a butterfly valve; 22. avoiding vibration of the throat; 23. a high pressure pump; 24. a motor; 25. a one-way valve; 26. a pressure regulating valve bank; 27. a high pressure filter; 28. an accumulator; 29. a pressure sensor; 3. an oil inlet ball valve group; 31. an oil inlet ball valve I; 32. an oil inlet ball valve II; 33. an oil inlet ball valve III; 34. an oil inlet ball valve IV; 35. an oil inlet ball valve V; 4. a two-way back pressure valve bank; 5. an oil return ball valve group; 51. an oil return ball valve I; 52. an oil return ball valve II; 53. an oil return ball valve III; 54. an oil return ball valve IV; 6. an oil tank; 61. an oil absorption area; 62. an oil return area; 63. a magnet; 7. a partition plate; 71. filtering with a screen; 8. an electric heater; 81. a temperature controller; 9. a liquid level controller; 91. a liquid level meter; 10. an oil cooler; 101. an oil return filter; 102. an air cleaner.

Detailed Description

The present invention will be described in further detail with reference to the following drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

A hydraulic system for testing service life reliability of an electromagnetic directional valve is shown in figure 1 and comprises two groups of parallel test loops 1 and two groups of parallel hydraulic power source systems 2 sharing an oil tank 6. As shown in fig. 1 or fig. 2, a partition 7 is arranged in the oil tank 6, the oil tank 6 is divided into an oil suction area 61 and an oil return area 62 by the partition 7, and both sets of hydraulic power source systems 2 are communicated with the oil suction area 61 of the oil tank 6. An oil inlet ball valve group 3 is arranged between the two sets of hydraulic power source systems 2 and the two sets of test loops 1, and three oil supply modes can be distributed between the two sets of hydraulic power source systems 2 and the two sets of test loops 1 by switching different states of the oil inlet ball valve group 3.

As shown in fig. 1 and 3, each set of test circuit 1 includes N valves 11 to be tested connected in parallel, each valve 11 to be tested includes an a port, a B port, a P port, and a T port, the P port of the valve 11 to be tested is connected to the hydraulic power source system 2, and the T port of the valve 11 to be tested is connected to the oil return area 62 of the oil tank 6. As shown in fig. 1 and 3, a pressure sensor 12 is connected to each of the ports a and B of each valve 11 to be tested, and a test damping device 13 located between the two pressure sensors 12 is further connected between the ports a and B of each valve 11 to be tested. Each pressure sensor 12 monitors the pressure of the port a or the port B of the valve 11 to be measured connected with the pressure sensor, the feedback pressure signal of each pressure sensor 12 records the pressure fluctuation waveform and the fluctuation number after passing through a recorder, and the service life and the reliability of the valve 11 to be measured are judged according to the pressure fluctuation waveform and the fluctuation number. In this embodiment, each group of test loops 1 includes 8 tested valves 11 connected in parallel, and the tested valves 11 are electromagnetic directional valves.

As shown in fig. 1 and 2, each set of hydraulic power source system 2 includes a high-pressure pump 23, a motor 24, and a two-way back pressure valve set 4, the motor 24 is electrically connected to the high-pressure pump 23, and the high-pressure pump 23 can manually adjust the magnitude of output flow. A butterfly valve 21 and a vibration-proof throat 22 are connected between an oil suction port of the high-pressure pump 23 and the oil tank 6, the butterfly valve 21 is located in an oil suction area 61 of the oil tank 6 and connected with the oil tank 6, and the vibration-proof throat 22 is located between the high-pressure pump 23 and the butterfly valve 21 and plays a role in vibration reduction. As shown in fig. 1 and 2, an oil outlet of the high-pressure pump 23 is connected with a check valve 25, an oil outlet of the check valve 25 is connected with a pressure regulating valve block 26, an oil outlet of the pressure regulating valve block 26 is connected with a high-pressure filter 27, the pressure regulating valve block 26 regulates pressure of oil supplied to the test circuit 1, and the high-pressure filter 27 filters the oil. As shown in fig. 1 and 2, the oil outlet of the two-way back pressure valve set 4 is connected to the oil return area 62 of the oil tank 6, and an oil return ball valve set 5 is arranged between the two test circuits 1 and the two-way back pressure valve set 4, and the two test circuits 1 can be arranged in three oil return modes by switching different states of the oil return ball valve set 5.

As shown in fig. 3, in this embodiment, the oil-inlet ball valve group 3 includes an oil-inlet ball valve i 31, an oil-inlet ball valve ii 32, an oil-inlet ball valve iii 33, an oil-inlet ball valve iv 34, and an oil-inlet ball valve v 35, where the oil-inlet ball valve i 31 and the oil-inlet ball valve ii 32 are respectively connected to oil outlets of each group of high-pressure filters 27, the oil-inlet ball valve iii 33 and the oil-inlet ball valve iv 34 are respectively disposed at oil inlets of a first tested valve 11 connected to the hydraulic power source system 2 in each group of test circuits 1, and the oil-inlet ball valve v 35 is disposed between the oil-inlet ball valve i 31, the oil-inlet ball. Oil can flow from the oil inlet ball valve I31 to the oil inlet ball valve III 33, and from the oil inlet ball valve II 32 to the oil inlet ball valve IV 34; or from the oil inlet ball valve I31 to the oil inlet ball valve V35 and then to the oil inlet ball valve IV 34; and from the oil inlet ball valve II 32 to the oil inlet ball valve V35 to the oil inlet ball valve III 33.

As shown in fig. 2, in the present embodiment, the oil return ball valve group 5 includes an oil return ball valve i 51, an oil return ball valve ii 52, an oil return ball valve iii 53, and an oil return ball valve iv 54, where the oil return ball valve i 51 and the oil return ball valve ii 52 are respectively connected to two back pressure valves in the two-way back pressure valve group 4, the oil return ball valve iii 53 is disposed between the oil return ball valve i 51 and the oil return ball valve ii 52, and the oil return ball valve iv 54 is connected in parallel with the two-way back pressure ball valve group and directly connected to the oil return area. The oil in one group of test loops 1 can directly flow back to the oil tank 6 from the return ball valve IV 54, can also flow back to the oil tank 6 from the return ball valve I51 through one of the backpressure valves, and can also flow back to the oil tank 6 from the return ball valve III 53 to the return ball valve II 52 through the other backpressure valve. The oil in the other group of test loops 1 can directly flow back to the oil tank 6 through the oil return ball valve II 52 to a back pressure valve, can also flow back to the oil tank 6 through the oil return ball valve III 53 to the oil return ball valve I51 and another back pressure valve, and can also directly flow back to the oil tank 6 through the oil return ball valve III 53 to the oil return ball valve IV 54.

As shown in fig. 2 or fig. 3, an accumulator 28 is connected to the oil outlets of the oil inlet ball valve iii 33 and the oil inlet ball valve iv 34, and the accumulator 28 is connected to the port P of each tested valve 11 in the group of test units, a pressure sensor 29 is provided between each accumulator 28 and the port P of the first tested valve 11 connected thereto, and the pressure sensor 29 is used for detecting the pressure of oil entering the port P of each tested valve 11, so as to regulate the pressure of the pressure regulating valve group 26. In the present embodiment, the pressure regulating valve bank 26 and the two-way back pressure valve bank 4 are both electromagnetic relief valves connected with a pressure reducing valve. Each pressure sensor 29 and each pressure sensor 12 can be selected from a digital display instrument, or can be independently connected with a pressure gauge, and the digital display instrument is selected in the embodiment.

As shown in fig. 2, a temperature controller 81, an electric heater 8, a liquid level meter 91 and a liquid level controller 9 are further arranged in the oil tank 6, the temperature controller 81, the electric heater 8 and the liquid level controller 9 are located in the oil absorption area 61 of the oil tank 6, the liquid level meter 91 is located in the oil return area 62 of the oil tank 6, and the liquid level meter 91 is matched with the liquid level controller 9 to ensure that oil in the oil tank 6 is sufficient and ensure normal test operation of the test circuit 1. As shown in fig. 2, a temperature controller 81 in communication control connection with the electric heater 8 is also arranged between each energy accumulator 28 and the corresponding pressure sensor 29, and the three temperature controllers 81 are used in cooperation with the electric heater 8 to ensure normal temperature of the oil liquid and meet the use requirement of the test circuit 1.

As shown in fig. 2, in addition to the oil return area 62 of the oil tank 6, an oil cooler 10 is connected to an outlet of the oil cooler 10, and an oil outlet of the oil cooler 101 is connected to the oil return area 62 of the oil tank 6. The oil return filter 101 performs temperature change interval control and oil contamination filtration on oil in the oil tank 6 together with the oil cooler 10 in the test process. As shown in fig. 2 and 4, the oil return area 62 of the oil tank 6 is further connected with an air cleaner 102, the partition 7 is further provided with a filter screen 71, and the bottom of the oil suction area 61 of the oil tank 6 is further provided with a magnet 63 for adsorbing metal impurities carried by oil in the circulation process, so that the cleanness of the oil is further ensured, and the normal operation of the test operation is ensured.

The communication of the oil passages of the above components is realized through pipeline connection, which is not described in detail.

The working principle and the using method of the invention are as follows:

as shown in fig. 1, two sets of hydraulic power source systems 2 provide oil for two sets of test circuits 1, and the on-off conditions of the oil inlet ball valve group 3 and the oil return ball valve group 5 are switched as required to realize the selection of three different oil supply modes. The oil liquid filtered by the pressure regulating valve group 26 and the high pressure filter 27 enters the P port of each tested valve 11 from the oil inlet ball valve group 3, and returns to the oil tank 6 from the T port of each tested valve 11 through the oil return ball valve group 5 and the two-way back pressure valve group 4, the pressure of the port a and the port B of each tested valve 11 after the buffering action of the test damping device 13 feeds back pressure signals through the corresponding pressure sensor 12, and the pressure change waveform and the change number are recorded after the recorder, and the service life and the reliability of the tested valve 11 are judged through the pressure change waveform and the change number.

While the foregoing description shows and describes the preferred embodiments of the present invention, it is to be understood that the invention is not limited to the forms disclosed herein, but is not to be construed as excluding other embodiments and is capable of use in various other combinations, modifications, and environments and is capable of changes within the scope of the inventive concept as described herein, commensurate with the above teachings, or the skill or knowledge of the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.