A hydraulic testing system and method for electro-hydraulic servo components

Abstract

This invention discloses a hydraulic testing system and method for electro-hydraulic servo components. The system includes a frame and an oil tank assembly, a power module, a hydraulic module, a loading module, a feedback module, and a main control module mounted on the frame. The hydraulic module achieves precise control of pressure and flow, providing stable hydraulic control support for the tested component. The loading module forms a bridge channel for the loading cylinder through a flow channel connected by a check valve and a relief valve within a second integrated block, enabling loading and oil replenishment of the loading cylinder to meet load testing requirements. The power module provides stable hydraulic oil to the tested component and the loading cylinder through an oil supply unit and an oil replenishment unit. The feedback module uses a tension / compression sensor, a follow-up piston displacement sensor, and a valve core position sensor to directly collect the valve core position, force, and displacement data of the tested component, avoiding interference from closed-loop testing. This system, through modular design and precise control, can meet multiple testing requirements for electro-hydraulic servo components.

Description

Technical Field

[0001] This invention relates to the field of hydraulic testing technology, and in particular to a hydraulic testing system and method for electro-hydraulic servo components. Background Technology

[0002] A hydraulic testing system is a device used to test and evaluate hydraulic components (such as hydraulic valves, hydraulic cylinders, pumps, motors, etc.) and their performance. It simulates different working conditions by controlling parameters such as hydraulic oil pressure, flow rate, and load, collecting data on the hydraulic system or components during operation, and analyzing their working status, dynamic response, and reliability.

[0003] The invention patent CN114060355A provides a hydraulic testing system, including an ultra-high pressure test oil circuit, a first low, medium and high pressure test oil circuit and a flushing pipeline oil circuit, a first motor pump set and a second motor pump set. It can perform tests under various working conditions by using the ultra-high pressure test oil circuit, the first low, medium and high pressure test oil circuit and the flushing pipeline oil circuit, which can effectively improve the testing efficiency. In particular, the flushing pipeline oil circuit can effectively clean the hydraulic pipeline, extend the service life of the pipeline, reduce hydraulic oil contamination and improve the testing accuracy.

[0004] However, although the hydraulic testing system in patent CN114060355A has multi-condition testing capabilities and improves pipeline cleanliness by setting up ultra-high pressure test oil circuit, low, medium and high pressure test oil circuit and flushing pipeline oil circuit, the system lacks direct measurement methods and open-loop test design for key parameters such as the dynamic characteristics of electro-hydraulic servo components, valve core position and flow rate. It cannot simulate complex working conditions or provide real-time load adjustment, and cannot meet the testing requirements for electro-hydraulic servo components. Summary of the Invention

[0005] Therefore, it is necessary to provide a hydraulic testing system and method for electro-hydraulic servo components, addressing the issue that the technical solutions of the aforementioned patents cannot meet the testing requirements for electro-hydraulic servo components.

[0006] This application provides a hydraulic testing system for an electro-hydraulic servo component, including a frame and an oil tank assembly, a power module, a hydraulic module, a loading module, a feedback module, and a main control module mounted on the frame.

[0007] The frame includes a base and a stand;

[0008] The hydraulic module is mounted on the base and includes a first integrated block, and a first relief valve, a safety valve, a flow valve, a first shut-off valve, an electro-hydraulic directional valve, a throttle valve, and a back pressure valve mounted on the first integrated block. The first relief valve, safety valve, flow valve, first shut-off valve, electro-hydraulic directional valve, throttle valve, and back pressure valve are connected through flow channels within the first integrated block. The hydraulic module is used to control the pressure changes of the hydraulic source and the movement of the valve core of the driving pressure regulating valve of the test element, and is also used to provide back pressure to the test element.

[0009] The loading module is mounted on the base and includes a second integrated block and a loading cylinder, as well as four first check valves, a second relief valve, and a first pressure gauge mounted on the second integrated block. The four first check valves, the second relief valves, the first pressure gauge, and the loading cylinder are connected through a flow channel within the second integrated block. The loading module is connected to the power module. The four check valves form a bridge channel for the extension and retraction of the loading cylinder, providing loading and oil replenishment channels for the loading cylinder.

[0010] The power module includes an oil supply unit for supplying oil to the test element and an oil replenishment unit for replenishing oil to the loading cylinder. The oil supply unit and the oil replenishment unit are respectively connected to the oil tank assembly and draw oil from the oil tank assembly. The hydraulic module and the power module are also used to provide a constant pressure dynamic switching parallel hydraulic source for the test element.

[0011] The test element and the loading cylinder are mounted on the stand. The feedback module is located between the piston rod of the follower differential cylinder of the test element and the piston rod of the loading cylinder. The feedback module includes a tension / compression sensor, a follower piston displacement sensor, and a valve core position sensor. The valve core position sensor is located on the valve core of the follower differential cylinder of the test element.

[0012] The main control module includes a control unit connected to the power module and the hydraulic module, a data acquisition unit connected to the tension / compression sensor, the follow-up piston displacement sensor and the valve core position sensor, and a processing unit. The control unit is used to control the power module and the hydraulic module, and the data acquisition unit and the processing unit are used to acquire and process the valve core position, force, displacement and flow data of the tested element.

[0013] Optionally, one end of the first relief valve, safety valve, flow valve, and first shut-off valve is connected in parallel and is respectively connected to the P port of the electro-hydraulic directional valve and the interface of the first integrated block connected to the loading module.

[0014] The other end of the first overflow valve, safety valve, flow valve, and shut-off valve is connected to the interface of the first integrated block that connects to the oil tank assembly;

[0015] The T port of the electro-hydraulic directional valve is connected to the inlet of the back pressure valve. The A port of the electro-hydraulic directional valve is also connected to a high-pressure filter and is connected to a pressure valve port of the test element through the high-pressure filter and the throttle valve. The B port of the electro-hydraulic directional valve is connected to another pressure valve port of the test electro-hydraulic servo element through the first integrated block.

[0016] The outlet of the back pressure valve on the first integrated block is connected to the upper interface of the oil tank assembly.

[0017] Optionally, the four first check valves are connected in pairs sequentially through the flow channels inside the second integrated block; the first end of the paired first check valves is connected to the interface of the second integrated block that connects to the hydraulic module; the second end of the paired first check valves is connected to the second relief valve and the first pressure gauge; the third and fourth ends of the paired first check valves are respectively connected to the interfaces of the second integrated block that connect to the two oil ports of the loading cylinder.

[0018] The outlet of the overflow valve on the second integrated block is connected to the upper interface of the oil tank assembly.

[0019] Optionally, the oil supply unit is mounted on the base and includes a first oil inlet filter, a first oil pump motor, a second check valve, and a first pressure line filter arranged in parallel. The first oil inlet filter, the first oil pump motor, the second check valve, and the pressure line filter are connected in sequence.

[0020] Optionally, the oil replenishment unit is mounted on the base and includes an inlet filter, a second oil pump motor, a third check valve, and a second pressure line filter connected in sequence. The second oil pump motor is connected to the oil tank assembly. The outlet of the second oil pump motor is connected to a valve module, which includes a loading relief valve, a solenoid directional valve, a second shut-off valve, and a second pressure gauge. The outlet of the loading relief valve is connected to the oil tank. One oil outlet of the valve module is connected to the working port of the solenoid directional valve, and the other oil outlet of the valve module is connected to the outlet of the second shut-off valve.

[0021] Optionally, an accumulator is provided at the outlet of the oil supply module, and the accumulator group is set on the base. The accumulator is also connected to the hydraulic module to maintain a constant oil supply pressure when the oil supply module switches oil supply sources, to supplement the instantaneous flow demand, and to smooth pressure pulsation.

[0022] Optionally, the hydraulic module further includes a pressure relay, a third pressure gauge, and a damper. The pressure relay is used to detect the pressure threshold of the hydraulic test system. When the pressure of the hydraulic test system reaches the set high pressure threshold, the microswitch of the pressure relay is activated. The pressure relay sends the signal of the microswitch activation to the main control module, which then controls the oil pump motor to stop. When the pressure of the hydraulic test system suddenly drops to the set low pressure threshold, the pressure relay outputs a signal to the main control module, which then controls the switching between oil pump motor units. The damper is used to smooth out pressure pulse impacts within the hydraulic module.

[0023] Optionally, the oil tank assembly includes an oil tank body, as well as a flow meter, a fourth check valve, a cooler, a temperature relay, a solenoid water valve, and a return oil filter;

[0024] The temperature relay is located outside the oil tank body and is used to detect the temperature of the oil tank body. The cooler is located on the top surface of the oil tank body. The inlet of the cooler is connected to the return port of the hydraulic module. The outlet of the cooler is connected to the flow meter and the fourth check valve in sequence. The electromagnetic water valve is used to control the on / off of the external water supply pump supplying water to the cooler.

[0025] The fuel tank body is also equipped with a liquid level control relay for detecting the oil level in the fuel tank body. The fuel tank body is also equipped with an air filter for maintaining the fuel tank body in balance with atmospheric pressure and filtering the air entering the fuel tank body.

[0026] Optionally, the first pressure line filter, the second pressure line filter, and the return oil filter are equipped with differential pressure transmitters. The differential pressure transmitters are used to detect the blockage of the first pressure line filter, the second pressure line filter, and the return oil filter, and to alert the main control module.

[0027] This application also provides a hydraulic testing method for electro-hydraulic servo components, including the aforementioned hydraulic testing system for electro-hydraulic servo components, and further including the following experimental procedures:

[0028] Setting up the test element: The test element and the loading cylinder are set at the upper and lower ends of the stand. The piston rod of the follower differential cylinder of the test element is connected to the piston rod of the loading cylinder. A tension and compression sensor and a follower piston displacement sensor are set between the piston rod of the follower differential cylinder of the test element and the piston rod of the loading cylinder. The valve core position sensor is set on the control valve core of the test element.

[0029] Input of control signals: The control unit of the main control module sends control signals to the hydraulic module, the power module and the test element;

[0030] Oil supply and loading of the test element: The hydraulic oil in the oil tank is delivered to the P port of the electro-hydraulic directional valve through the first motor oil pump group in the oil supply unit. After the electro-hydraulic directional valve is switched to the working left position by power, the valve position remains unchanged. The hydraulic oil flows out from the A port of the electro-hydraulic directional valve, passes through the first oil inlet filter and the throttle valve and enters the upper and lower chambers of the follower piston of the test element. The up and down movement of the follower piston and the hydraulic oil pressure difference of the test element are controlled by adjusting the magnitude and direction of the input current.

[0031] As the input current of the control unit gradually increases, the pressure at the variable throttle port on the follower piston increases, and the hydraulic oil pushes the follower piston downward. The hydraulic oil flows back to the oil tank through the T port of the electro-hydraulic directional valve, the back pressure valve, the flow meter, the check valve and the filter.

[0032] When the input current gradually decreases to zero, the follower piston stops moving and maintains its current position; at this time, the flow of hydraulic oil is balanced by the oil circuit of the power source, electro-hydraulic directional valve, back pressure valve and throttle valve to maintain constant pressure;

[0033] When the input current increases in the reverse direction, the pressure at the variable throttle port of the follower piston increases, and the hydraulic oil pushes the follower piston upward. The hydraulic oil flows back to the oil tank through the T port of the electro-hydraulic directional valve, the back pressure valve, the flow meter, the check valve and the filter.

[0034] Oil replenishment and loading of the loading cylinder: The hydraulic oil in the tank is delivered to the P port of the solenoid directional valve in the loading module via the second motor oil pump group in the loading replenishment power module. After the solenoid directional valve is energized and in the left position, it remains unchanged, allowing the hydraulic oil to flow out from the A port of the solenoid directional valve. After passing through the loading relief valve and the one-way valve bridge channel in the loading module, the replenishing oil enters the forward cavity of the loading cylinder. The piston rod of the loading cylinder moves outward under the drag of the tested electro-hydraulic servo element. At the same time, the hydraulic oil in the retraction cavity of the loading cylinder is squeezed and flows back to the tank through the one-way valve and the loading relief valve.

[0035] During the oil replenishment and loading process, the oil supply pressure of the loading cylinder is set constant by the overflow valve of the power module. The loading overflow valve adjusts the loading pressure of the loading cylinder in real time until the loading pressure reaches the load pressure value required by the test. The main control module monitors the loading pressure value through the control unit. When the electro-hydraulic servo component under test reaches the specified position or the adjusted loading pressure exceeds the actual required value, the loading cylinder stops moving.

[0036] Acquisition and processing of parameters of the tested element: The acquisition unit of the main control module acquires the load force signal, piston displacement signal and valve core position signal fed back by the tension and compression sensor, the follow-up piston displacement sensor and the valve core position sensor in real time. The processing unit generates various characteristic curves of the tested element based on the load force parameter, valve core position parameter, piston displacement parameter and the flow parameter obtained from the piston displacement parameter.

[0037] Compared with the prior art, the technical solution provided in this application has the following advantages:

[0038] The aforementioned electro-hydraulic servo component hydraulic testing system, through the coordinated operation of the hydraulic module, loading module, power module, and feedback module, meets the multiple functional testing requirements of the tested component. The hydraulic module, connected by flow channels within the first integrated block, achieves precise control of pressure and flow, providing stable hydraulic control support for the tested component and providing back pressure to adapt to various test conditions. The loading module, connected by check valves and relief valves within the second integrated block, forms a bridge channel for the loading cylinder, enabling loading and oil replenishment to meet load testing requirements. The power module, through oil supply and replenishment units, provides stable hydraulic oil to the tested component and the loading cylinder. The feedback module employs tension / compression sensors, a follow-up piston displacement sensor, and a valve core position sensor. The valve core position sensor is installed on the valve core of the pressure regulating valve of the tested component, directly acquiring the valve core position, force, and displacement data, avoiding interference from closed-loop testing. The main control module controls the power module and hydraulic module, while simultaneously acquiring and processing test data to ensure the accuracy and reliability of the test. This system, through modular design and precise control, can meet a variety of testing requirements for electro-hydraulic servo components. Attached Figure Description

[0039] Figure 1 A hydraulic schematic diagram of a hydraulic testing system for a liquid servo component provided in an embodiment of this application;

[0040] Figure 2 This is a front view of a hydraulic testing system for a liquid servo component provided in an embodiment of this application;

[0041] Figure 3 This is a top view of a hydraulic testing system for a liquid servo element provided in an embodiment of this application.

[0042] Explanation of reference numerals in the attached figures:

[0043] 1. Oil tank assembly; 2. First inlet oil filter; 3. Accumulator; 4. First oil pump motor; 5. Second check valve; 6. Flow valve; 7. First pressure line filter; 8. Back pressure valve; 9. Electro-hydraulic directional valve; 10. Third pressure gauge; 11. Pressure sensor; 12. Pressure relay; 13. High-pressure filter; 14. Throttle valve; 15. Test element; 16. Loading cylinder; 17. Tension / compression sensor; 18. Displacement sensor; 19. Position sensor; 20. First pressure gauge; 21. First check valve; 22. Second relief valve; 23. First relief valve; 24. 25. Safety valve; 26. Flow meter; 27. Fourth check valve; 28. Solenoid directional valve; 29. ​​Second pressure gauge; 30. Return oil filter; 31. Second pressure line filter; 32. Third check valve; 33. Loading relief valve; 34. Second oil pump motor unit; 35. Solenoid water valve; 36. Cooler; 37. Second inlet oil filter; 38. Temperature relay; 39. Liquid level control relay; 40. Air filter; 41. Hydraulic module; 42. Oil replenishment unit; 43. Main control module; 44. Oil supply unit; 45. Loading module; 46. Stand; 47. Base. Detailed Implementation

[0044] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0045] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0046] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0047] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0048] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0049] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0050] See Figures 1 to 3 An embodiment of the present invention provides a hydraulic testing system for an electro-hydraulic servo component, including a frame and an oil tank assembly 1, a power module, a hydraulic module 40, a loading module 44, a feedback module, and a main control module 42 mounted on the frame.

[0051] The frame includes a base 46 and a stand 45;

[0052] The hydraulic module 40 is mounted on the base 46 and includes a first integrated block, and a first relief valve 23, a safety valve 24, a flow valve 6, a first shut-off valve, an electro-hydraulic directional valve 9, a throttle valve 14, and a back pressure valve 8 mounted on the first integrated block. The first relief valve 23, safety valve 24, flow valve 6, first shut-off valve, electro-hydraulic directional valve 9, throttle valve 14, and back pressure valve 8 are connected through flow channels within the first integrated block. The hydraulic module 40 is used to control the pressure changes of the hydraulic source and the movement of the valve core of the driving pressure regulating valve of the test element 15, and is also used to provide back pressure for the test element 15.

[0053] The loading module 44 is mounted on the base 46 and includes a second integrated block and a loading cylinder, as well as four first check valves 21, second relief valves 22, and a first pressure gauge 20 mounted on the second integrated block. The four first check valves 21, second relief valves 22, first pressure gauges 20, and the loading cylinder are connected through a flow channel within the second integrated block. The loading module 44 is connected to the power module. The four check valves form a bridge channel in both directions of the loading cylinder's extension and retraction, providing loading and oil replenishment channels for the loading cylinder.

[0054] The power module includes an oil supply unit 43 that supplies oil to the test element 15 and an oil replenishment unit 41 that replenishes oil to the loading cylinder. The oil supply unit 43 and the oil replenishment unit 41 are respectively connected to the oil tank assembly 1 and draw oil from the oil tank assembly 1. The hydraulic module 40 and the power module are also used to provide a constant pressure dynamic switching parallel hydraulic source for the test element 15.

[0055] The test element 15 and the loading cylinder are mounted on the stand 45. The feedback module is located between the piston rod of the follower differential cylinder of the test element 15 and the piston rod of the loading cylinder. The feedback module includes a tension / compression sensor 17, a follower piston displacement sensor 18 and a valve core position sensor 19 connected in sequence. The valve core position sensor 19 is located on the valve core of the follower differential cylinder of the test element 15.

[0056] The main control module 42 includes a control unit connected to the power module and the hydraulic module 40, a data acquisition unit connected to the tension and compression sensor 17, the follow-up piston displacement sensor 18 and the valve core position sensor 19, and a processing unit. The control unit is used to control the power module and the hydraulic module 40, and the data acquisition unit and the processing unit are used to acquire and process the valve core position, force, displacement and flow data of the tested element 15.

[0057] The electro-hydraulic servo component hydraulic testing system provided in this embodiment of the invention, through the cooperation of the hydraulic module 40, loading module 44, power module, and feedback module, meets the multiple functional testing requirements of the test component 15. The hydraulic module 40, connected by flow channels within the first integrated block, achieves precise control of pressure and flow, providing stable hydraulic support for the test component 15 and providing back pressure to adapt to various test conditions. The loading module 44, connected by check valves and relief valves within the second integrated block, forms a bridge channel for the loading cylinder, enabling loading and oil replenishment of the loading cylinder to meet load test requirements. The power module, through the oil supply unit 43 and oil replenishment unit 41, provides stable hydraulic oil to the test component 15 and the loading cylinder. The feedback module uses a tension / compression sensor 17, a follow-up piston displacement sensor 18, and a valve core position sensor 19 to directly collect the valve core position, force, and displacement data of the test component 15, avoiding interference from closed-loop testing. The main control module 42 is responsible for controlling the power module and hydraulic module 40, while simultaneously collecting and processing test data to ensure the accuracy and reliability of the test. This system, through modular design and precise control, can meet a variety of testing requirements for electro-hydraulic servo components.

[0058] In the electro-hydraulic servo component hydraulic test system provided in this embodiment, one end of the first relief valve 23, safety valve 24, flow valve 6, and first shut-off valve is connected in parallel and is connected to the P port of the electro-hydraulic directional valve 9 and the interface of the first integrated block connecting loading module 44, respectively.

[0059] The other end of the first overflow valve 23, safety valve 24, flow valve 6, and shut-off valve is connected to the interface of the first integrated block connecting the oil tank assembly 1.

[0060] The T port of the electro-hydraulic directional valve 9 is connected to the inlet of the back pressure valve 8. The A port of the electro-hydraulic directional valve 9 is also connected to a high-pressure filter 13, and is sequentially connected to a pressure valve port of the test element 15 through the high-pressure filter 13 and the throttle valve 14. The B port of the electro-hydraulic directional valve 9 is connected to another pressure valve port of the test electro-hydraulic servo element through the first integrated block.

[0061] The outlet of the back pressure valve 8 on the first integrated block is connected to the oil tank assembly 1.

[0062] In this embodiment, by setting a first integrated block, the flow channels of the first relief valve 23, safety valve 24, flow valve 6, first shut-off valve, electro-hydraulic directional valve 9, throttle valve 14 and back pressure valve 8 are integrated to form a pipeless connection. This not only simplifies the connection path between hydraulic valves and reduces the complexity of pipeline layout, but also improves the reliability of the system, reduces the risk of oil leakage, further optimizes the spatial layout of the system, and makes the system structure more compact, meeting the needs of high efficiency and reliability of hydraulic testing equipment.

[0063] In the electro-hydraulic servo component hydraulic test system provided in this embodiment, four first check valves 21 are connected in pairs sequentially through the flow channels inside the second integrated block; the first end of the paired first check valves 21 is connected to the interface of the hydraulic module 40 connected to the second integrated block; the second end of the paired first check valves 21 is connected to the second relief valve 22 and the first pressure gauge 20; the third and fourth ends of the paired first check valves 21 are respectively connected to the interfaces of the two oil ports of the loading cylinder connected to the second integrated block; the outlet of the relief valve on the second integrated block is connected to the oil tank assembly 1.

[0064] In this embodiment, four first one-way valves 21 are connected in pairs through the internal flow channels of the second integrated block of the loading module 44, forming a bridge channel for the extension and retraction of the loading cylinder in both directions. This allows the loading cylinder to flexibly follow the movement of the electro-hydraulic servo component under test under its active traction. The loading cylinder achieves pressure adjustment through the loading overflow valve 32. The dynamically changing pressure provides different loads to the electro-hydraulic servo component under test, thereby meeting the diverse loading conditions required for the component 15 during the test.

[0065] In the electro-hydraulic servo component hydraulic test system provided in this embodiment, the oil supply unit 43 is mounted on the base 46 and includes a first oil inlet filter, a first oil pump motor 4, a second check valve 5, and a first pressure pipeline filter 7 arranged in parallel. The first oil inlet filter, the first oil pump motor 4, the second check valve 5, and the pressure pipeline filter are connected in sequence.

[0066] In this embodiment, the oil pump is a positive displacement pump, which can be a fixed displacement gear pump, a vane pump, or a variable displacement piston pump. The output flow rate is adjusted by regulating the variable displacement mechanism of the variable displacement piston pump. The oil inlet of the first oil pump motor 4 is connected to the oil tank assembly 1, and the oil outlet of the first oil pump motor 4 is connected to the hydraulic module 40 through a pipe joint. A pipe joint is provided at the oil inlet of the hydraulic module 40, and the oil outlet is connected to the connection flange of the test element 15 on the stand 45 through a steel pipe.

[0067] In the electro-hydraulic servo component hydraulic test system provided in this embodiment, the oil replenishment unit 41 is set on the base 46 and includes an inlet filter, a second oil pump motor, a third check valve 31, and a second pressure pipeline filter 30 connected in sequence. The second oil pump motor is connected to the oil tank assembly 1. The outlet of the second oil pump motor is connected to a valve module, which includes a loading relief valve 32, a solenoid directional valve 27, a second shut-off valve, and a second pressure gauge 28. The outlet of the loading relief valve 32 is connected to the oil tank. One oil outlet of the valve module is connected to the working port of the solenoid directional valve 27, and the other oil outlet of the valve module is connected to the outlet of the second shut-off valve.

[0068] In the electro-hydraulic servo component hydraulic test system provided in this embodiment, an accumulator 3 is provided at the outlet of the oil supply module. The accumulator 3 group is set on the base 46. The accumulator 3 is also connected to the hydraulic module 40 to maintain a constant oil supply pressure when the oil supply module switches the oil supply source, to supplement the instantaneous flow demand, and to smooth pressure pulsation.

[0069] In the electro-hydraulic servo component hydraulic testing system provided in this embodiment, the hydraulic module 40 also includes a pressure relay 12, a third pressure gauge 10, and a damper. The pressure relay 12 is used to detect the pressure threshold of the hydraulic testing system. When the pressure of the hydraulic testing system reaches the set high pressure threshold, the micro switch of the pressure relay 12 is activated, and the pressure relay 12 sends the signal of the micro switch activation to the main control module 42, which controls the oil pump motor to stop. When the pressure of the hydraulic testing system suddenly drops to the set low pressure threshold, the pressure relay 12 outputs a signal to the main control module 42, which controls the switching between oil pump motor groups. The damper is used to smooth out pressure pulse impacts within the hydraulic module 40.

[0070] In this embodiment, during the operation of the hydraulic testing system, the pressure relay 12 is used to detect the pressure threshold within the system in real time. When the pressure of the hydraulic testing system reaches the set high-pressure threshold, the microswitch of the pressure relay 12 is triggered and closes, sending its detection signal to the control unit of the main control module 42. The control unit controls the motor oil pump to stop according to the signal command, thereby ensuring that the hydraulic testing system will not be damaged due to overpressure during operation, thus playing a role in system protection.

[0071] When the pressure of the hydraulic testing system suddenly drops to the set low-pressure threshold, the pressure relay 12 outputs a signal to the main control module 42. Upon receiving the signal, the main control module 42 instructs to switch the operating state of the motor-driven oil pump group, activating the backup motor-driven oil pump to supplement the pressure, thereby maintaining the stability of the hydraulic testing system's working pressure and ensuring the continuity and reliability of the testing process. Furthermore, the hydraulic module 40, by incorporating a damping device, effectively suppresses pressure shocks and fluctuations within the system, further enhancing the stability of the hydraulic testing system's operation. The damping device enables the system to maintain stable pressure under dynamic conditions, ensuring the accuracy of test data and the safety of the equipment.

[0072] In the electro-hydraulic servo component hydraulic test system provided in this embodiment, the oil tank assembly 1 includes an oil tank body, a flow meter 25, a fourth check valve 26, a cooler 35, a temperature relay 37, a solenoid water valve 34, and a return oil filter 29.

[0073] Temperature relay 37 is installed on the outside of the oil tank body to detect the temperature of the oil tank body. Cooler 35 is installed on the top surface of the oil tank body. The inlet of cooler 35 is connected to the oil return port of hydraulic module 40. The outlet of cooler 35 is connected to flow meter 25 and fourth check valve 26 in sequence. Electromagnetic water valve 34 is used to control the on / off of water supply from external water pump to cooler 35.

[0074] The oil tank also includes a level control relay 38 for detecting the oil level. An air filter is also installed inside the tank to maintain pressure balance between the tank and atmospheric pressure and to filter incoming air. In this embodiment, the level control relay 38 includes two floats, which are used to set upper and lower levels respectively. When the level reaches the lower limit, the level control relay 38 sends a signal to the main control module 42 to control the external oil supply equipment of the hydraulic test system to replenish hydraulic oil to the tank. When the level reaches the upper limit, the level control relay 38 sends a signal to the main control module 42 to shut off the oil supply equipment, preventing overfilling. An air filter 39 is installed on the top of the tank, serving as both a breather and a refueling filter. The air filter 39 filters the air entering the tank, isolating external dust and particles to keep the oil clean. When the oil level rises, the air filter 39 discharges air; when the oil level drops, it draws in external air to maintain pressure balance inside and outside the tank and prevent cavitation.

[0075] Before the hydraulic test system starts operating, the external water supply pump motor is started, allowing external water to enter the cooler 35 and form a water circulation to cool the hydraulic oil in the tank. Under normal circumstances, the solenoid water valve 34 is in the open state, and the temperature of the tank is monitored in real time by the temperature relay 37. When the temperature of the tank exceeds the set high-temperature threshold, the high-temperature contact of the temperature relay 37 connects, and the temperature relay 37 sends a signal to the main control module 42. The main control module 42 controls the relay to open the solenoid water valve 34, controlling the external water supply pump to start supplying water to cool the tank. When the temperature is lower than the set low-temperature threshold, the low-temperature contact of the temperature relay 37 connects, and the main control module 42 closes the solenoid water valve 34, stopping the cooling cycle. The inlet of the cooler 35 is connected to the return oil port of the hydraulic module 40, and the outlet is connected in sequence to the flow meter 25 and the fourth check valve 26. The flow meter 25 measures the return oil flow and uploads it to the measurement and control system. The fourth check valve 26 is used to branch the return oil and act as a back pressure to ensure stable return oil pressure.

[0076] In the electro-hydraulic servo component hydraulic testing system provided in this embodiment, differential pressure transmitters are installed in the first pressure line filter 7, the second pressure line filter 30, and the return oil filter 29. These transmitters detect the blockage status of the first pressure line filter 7, the second pressure line filter 30, and the return oil filter 29, and send an alarm to the main control module 42. When filter element blockage causes the differential pressure to reach a set value, the blockage contact of the differential pressure transmitter connects, sending a signal to the main control module 42. The main control module 42 then issues an alarm signal, prompting the operator to replace the filter element to ensure the cleanliness of the system oil.

[0077] An embodiment of the present invention also provides a hydraulic testing method for an electro-hydraulic servo component, including the aforementioned hydraulic testing system for an electro-hydraulic servo component, and further including the following experimental process:

[0078] Setting of test element 15: The test element 15 and the loading cylinder are set at the upper and lower ends of the stand 45. The piston rod of the follower differential cylinder of the test element 15 is connected to the piston rod of the loading cylinder. A tension and pressure sensor 17 and a follower piston displacement sensor 18 are set between the piston rod of the follower differential cylinder of the test element 15 and the piston rod of the loading cylinder. The valve core position sensor 19 is set on the control valve core of the test element 15.

[0079] Input of control signals: The control unit of the main control module 42 sends control signals to the hydraulic module 40, the power module and the test element 15;

[0080] Oil supply and loading of test element 15: The hydraulic oil in the oil tank is delivered to the P port of the electro-hydraulic directional valve 9 through the first motor oil pump group in the oil supply unit 43. After the electro-hydraulic directional valve 9 is switched to the working left position by power, the valve position remains unchanged. The hydraulic oil flows out from the A port of the electro-hydraulic directional valve 9, passes through the first oil inlet filter and the throttle valve 14 and enters the upper and lower chambers of the follower piston of the test element 15. The main control module 42 controls the up and down movement of the follower piston of the test element 15 and the hydraulic oil pressure difference by adjusting the magnitude and direction of the input current.

[0081] As the input current of the control unit gradually increases, the pressure at the variable throttle port on the follower piston increases, and the hydraulic oil pushes the follower piston downward. The hydraulic oil flows back to the oil tank through the T port of the electro-hydraulic directional valve 9, the back pressure valve 8, the flow meter 25, the check valve and the filter.

[0082] When the input current gradually decreases to zero, the follower piston of the tested element 15 stops moving and maintains its current position; at this time, the flow of hydraulic oil is balanced by the oil circuit of the power source, electro-hydraulic directional valve 9, back pressure valve 8 and throttle valve 14 to maintain constant pressure.

[0083] When the input current increases in the reverse direction, the pressure at the variable throttle port of the follower piston of the test element 15 increases, and the hydraulic oil pushes the follower piston upward. The hydraulic oil flows back to the oil tank through the T port of the electro-hydraulic directional valve 9, the back pressure valve 8, the flow meter 25, the check valve and the filter.

[0084] Oil replenishment and loading of the loading cylinder: The hydraulic oil in the tank is delivered to the P port of the solenoid directional valve 27 in the loading module 44 via the second motor oil pump group in the loading replenishment power module. After the solenoid directional valve 27 is energized and in the left position, it remains unchanged, so that the hydraulic oil flows out from the A port of the solenoid directional valve 27, passes through the loading relief valve 32 and the one-way valve bridge channel in the loading module 44, and replenishes the oil into the forward cavity of the loading cylinder. The piston rod of the loading cylinder moves outward under the drag of the tested electro-hydraulic servo element; at the same time, the hydraulic oil in the retraction cavity of the loading cylinder is squeezed and flows back to the tank through the one-way valve and the loading relief valve 32.

[0085] During the oil replenishment and loading process, the oil supply pressure of the loading cylinder is set constant by the overflow valve of the power module. The loading overflow valve 32 adjusts the loading pressure of the loading cylinder in real time until the loading pressure reaches the load pressure value required by the test. The main control module 42 monitors the loading pressure value through the control unit. When the electro-hydraulic servo component under test reaches the specified position or the adjusted loading pressure exceeds the actual required value, the loading cylinder stops moving.

[0086] Acquisition and processing of parameters of the tested element 15: The acquisition unit of the main control module 42 acquires the load force signal, piston displacement signal and valve core position signal fed back by the tension and compression sensor 17, the follow-up piston displacement sensor 18 and the valve core position sensor 19 in real time. The processing unit generates various characteristic curves of the tested element 15 based on the load force parameter, valve core position parameter, piston displacement parameter and the flow parameter obtained from the piston displacement parameter.

[0087] In this embodiment, when conducting no-load related tests on the test element 15, the fourth shut-off valve J4, the seventh shut-off valve J7, and the third shut-off valve J3 are first opened, and the first shut-off valve J1 and the eighth shut-off valve J8 are closed. The connection between the loading cylinder and the test element 15 is disconnected, and the electro-hydraulic directional valve 9 is energized and switched to the working left position. This allows the high-pressure oil to pass through the filter and the throttle valve 14 to reach the variable throttle port on the follower piston of the electro-hydraulic servo element under test. The pressure oil flows from the variable throttle port under the follower piston through the electro-hydraulic directional valve 9T port, the back pressure valve 8, the flow meter 25, the check valve, the filter, and the cooler 35 back to the oil tank.

[0088] When performing load-related tests on the test element 15, first open the fourth shut-off valve J4, the seventh shut-off valve J7, the third shut-off valve J3, the sixth shut-off valve J6, the second shut-off valve J2, and the ninth shut-off valve J9, and close the first shut-off valve J1, the eighth shut-off valve J8, the tenth shut-off valve J10, and the eleventh shut-off valve J11. The oil in the tank is sequentially transported to the P port of the solenoid directional valve 27 through the second oil pump motor 33, the third check valve 31, and the second pressure pipeline filter 30 of the oil replenishment unit 41. Adjust the loading overflow valve 32 in the valve module until the pressure oil in the valve module reaches the oil replenishment control pressure. The solenoid directional valve 27 is energized and switched to the working left position, so that the pressure oil reaches the front end of the paired check valve of the second integrated block in the loading module 44, and then enters the forward cavity of the loading cylinder through the check valve bridge channel to expand the cavity, squeezing out the oil in the cavity of the loading cylinder. The squeezed-out oil flows back to the tank through the loading overflow valve 32.

[0089] Alternatively, first open the fourth shut-off valve J4, the seventh shut-off valve J7, the third shut-off valve J3, and the eighth shut-off valve J8, and close the ninth shut-off valve J9, the tenth shut-off valve J10, and the eleventh shut-off valve J11. Adjust the loading overflow valve 32 and the safety valve 24 in the valve module to the oil supply pressure. The branch of the pressurized oil output by the oil supply unit 43 in the power module reaches the front end of the paired one-way valve of the second integrated block in the loading module 44, and then enters the forward cavity of the loading cylinder through the one-way valve bridge channel to supplement the oil in the forward cavity enlargement cavity, squeezing out the oil in the cavity shrinking cavity of the loading cylinder. The squeezed oil flows back to the oil tank through the loading overflow valve 32.

[0090] Specifically, in this embodiment, the test on the test element 15 includes the following:

[0091] Displacement (flow rate) characteristic test under no-load conditions: When the load pressure difference ΔpL is 0 and the oil supply pressure ps is constant, the main control module 42 inputs a current i that changes according to one working cycle (i.e., from 0→imax+→0→imax-→0), and collects the displacement s of the follower piston of the test element 15 accordingly, thereby indirectly obtaining the change in the output flow rate q of the test element 15. The resulting curve is the no-load displacement (flow rate) characteristic of the test element 15, where the flow rate is collected by the follower piston displacement sensor 18, and the data change of the flow meter 25 is observed at the same time.

[0092] Displacement (flow rate) characteristic test under load: The main control module 42 keeps the input current i constant, while controlling the load pressure difference ΔpL to vary from 0 to ps (load force f). Within this range, the displacement s (i.e., the output flow rate q of the test element 15) of the follower piston is collected. By changing the input current i to different constants, the curve obtained by the main control module 42 is the load displacement (flow rate) characteristic curve.

[0093] Throttling characteristic test: With the oil supply pressure ps as constant, the main control module 42 inputs a current i that changes according to one working cycle (i.e., from 0→imax+→0→imax-→0), and the corresponding change in output displacement is collected. The curve plotted is the throttling characteristic curve.

[0094] Zero-consumption flow rate: When the oil supply pressure ps of the tested element 15 is constant, the main control module 42 inputs current i, the acquisition unit collects the flow rate qr flowing out of its leakage port, and the processing unit plots the zero-consumption flow rate-current curve.

[0095] Oil supply pressure zero drift: With the load pressure difference ΔpL at 0 and the oil supply pressure ps constant, the main control unit inputs a triangular wave current to obtain the flow rate q near the zero position of the tested element 15 (obtained through the displacement s of the follower piston), which is the zero drift. Based on the change in oil supply pressure ps, the characteristic curve of zero drift versus oil supply pressure is obtained. The ratio of 60% to 100% oil supply pressure zero drift is found from the curve and expressed as a percentage.

[0096] Load zero drift: With the load pressure difference ΔpL at 0 and the oil supply pressure ps constant, the main control unit inputs a triangular wave current to obtain the flow rate q (displacement s) near the zero position of the tested element 15, i.e., zero bias. Based on the change in oil supply pressure ps, the characteristic curve of zero bias as a function of load (psA) is obtained. The load zero bias value at 60%–100% oil supply pressure is found from the curve and expressed in mm.

[0097] Frequency dynamic characteristic test: The main control module 42 inputs a current that varies sinusoidally within a certain frequency range, and collects the complex ratio of the no-load flow rate of the valve under test 15 to the input current, which is the frequency characteristic of the valve under test 15.

[0098] Power module switching pressure change: When switching from one fuel supply power source to another, first start the other fuel supply power source to supply fuel to both sources simultaneously, then stop the original fuel supply power source, and the fuel supply pressure ps and load pressure difference ΔpL are kept constant.

[0099] Strain capability: The oil supply pressure ps is constant. The main control module 42 inputs a current i that changes according to one working cycle (i.e., from 0→imax+→0→imax-→0). The valve position of the electro-hydraulic directional valve 9 is switched to the non-working position, i.e., the right position. The tested element 15 moves to the bottom of the full stroke of the piston.

[0100] In this embodiment, by installing a valve core position sensor 19 on the control valve core of the follow-up differential cylinder of the test element 15, the displacement signal of the valve core can be directly acquired, forming a precise correspondence with the input current of the main control module 42. This direct position feedback method avoids the error accumulation of traditional indirect deduction of valve core position through flow rate or pressure, realizes high-precision measurement of dynamic response characteristics and zero flow consumption, and provides a reliable basis for evaluating the dynamic performance of the test element 15.

[0101] Meanwhile, this embodiment adopts an open-loop testing method. Through the precise control of the hydraulic module 40 and the power module by the main control module 42, the valve core position, flow rate, and pressure are dynamically adjusted by adjusting the input current, thus avoiding the feedback signal interference problem in closed-loop testing. The control lag and oscillation phenomena commonly found in closed-loop testing are effectively eliminated, thereby ensuring the authenticity and stability of the test data, especially in tests such as throttling characteristic test and zero drift of oil supply pressure.

[0102] In load-related tests, the loading module 44 adjusts the loading pressure of the loading cylinder in real time via an overflow valve, moving in tandem with the tested element 15 to provide dynamic load support. The dynamic loading capability of the loading cylinder avoids the error accumulation problem of traditional closed-loop regulation, ensuring high accuracy in load displacement (flow) characteristic tests. Simultaneously, the oil supply pressure is strictly controlled to remain constant during the oil replenishment and loading process of the loading cylinder, making the load pressure adjustment process smoother and providing reliable support for dynamic characteristic tests.

[0103] The main control module 42, through its acquisition and processing units, enables real-time acquisition and analysis of multiple parameters such as valve core position, load force, piston displacement, and flow rate, generating various test curves including no-load displacement (flow rate) characteristics, loaded displacement (flow rate) characteristics, zero-consumption flow rate, and frequency dynamic characteristics. This synchronous acquisition method of multi-dimensional parameters makes the test data more comprehensive and can clearly reflect the dynamic performance and overall characteristics of the tested component 15.

[0104] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0105] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A hydraulic testing system for an electro-hydraulic servo component, the system comprising a frame and an oil tank assembly (1), a power module, a hydraulic module (40), a loading module (44), a feedback module, and a main control module (42) mounted on the frame, characterized in that, The frame includes a base (46) and a stand (45); The hydraulic module (40) is mounted on the base (46) and includes a first integrated block, and a first relief valve (23), a safety valve (24), a flow valve (6), a first shut-off valve, an electro-hydraulic directional valve (9), a throttle valve (14), and a back pressure valve (8) mounted on the first integrated block. The first relief valve (23), the safety valve (24), the flow valve (6), the first shut-off valve, the electro-hydraulic directional valve (9), the throttle valve (14), and the back pressure valve (8) are connected by a flow channel mounted in the first integrated block. The hydraulic module (40) is used to control the pressure change of the hydraulic source and to control the movement of the valve core of the driving pressure regulating valve of the test element (15). It is also used to provide back pressure to the test element (15). The loading module (44) is mounted on the base (46) and includes a second integrated block and a loading cylinder, as well as four first check valves (21), a second overflow valve (22), and a first pressure gauge (20) mounted on the second integrated block. The four first check valves (21), the second overflow valves (22), the first pressure gauge (20), and the loading cylinder are connected through a flow channel mounted in the second integrated block. The loading module (44) is connected to the power module. The four check valves form a bridge channel for the extension and retraction of the loading cylinder, providing a loading and oil replenishment channel for the loading cylinder. The power module includes an oil supply unit (43) for supplying oil to the test element (15) and an oil replenishment unit (41) for replenishing oil to the loading cylinder. The oil supply unit (43) and the oil replenishment unit (41) are respectively connected to the oil tank assembly (1) and draw oil from the oil tank assembly (1). The hydraulic module (40) and the power module are also used to provide a constant pressure dynamic switching parallel hydraulic source for the test element (15). The test element (15) and the loading cylinder are mounted on the stand (45). The feedback module is located between the piston rod of the follower differential cylinder of the test element (15) and the piston rod of the loading cylinder. The feedback module includes a tension / compression sensor (17), a follower piston displacement sensor (18), and a valve core position sensor (19). The valve core position sensor (19) is located on the valve core of the follower differential cylinder of the test element (15). The main control module (42) includes a control unit connected to the power module and the hydraulic module (40), a data acquisition unit connected to the tension and pressure sensor (17), the follow-up piston displacement sensor (18) and the valve core position sensor (19), and a processing unit. The control unit is used to control the power module and the hydraulic module (40), and the data acquisition unit and the processing unit are used to acquire and process the valve core position, force, displacement and flow data of the tested element (15).

2. The electro-hydraulic servo component hydraulic testing system according to claim 1, characterized in that, The first overflow valve (23), safety valve (24), flow valve (6), and first shut-off valve are connected in parallel at one end of their respective ports and are connected to the P port of the electro-hydraulic directional valve (9) and the interface of the first integrated block connected to the loading module (44). The other end of the first overflow valve (23), safety valve (24), flow valve (6), and shut-off valve is connected to the interface of the first integrated block connected to the oil tank assembly (1); The T port of the electro-hydraulic directional valve (9) is connected to the inlet of the back pressure valve (8). The A port of the electro-hydraulic directional valve (9) is also connected to a high-pressure filter (13), and is connected to a pressure valve port of the test element (15) through the high-pressure filter (13) and the throttle valve (14). The B port of the electro-hydraulic directional valve (9) is connected to another pressure valve port of the test electro-hydraulic servo element through the first integrated block. The back pressure valve (8) is connected to the oil tank assembly (1) at its outlet on the first integrated block.

3. The electro-hydraulic servo component hydraulic testing system according to claim 1, characterized in that, The four first check valves (21) are connected in pairs sequentially through the flow channels inside the second integrated block; the first end of the first check valve (21) connected in pairs is connected to the interface of the second integrated block that connects to the hydraulic module (40); the second end of the first check valve (21) connected in pairs is connected to the second relief valve (22) and the first pressure gauge (20); the third and fourth ends of the first check valve (21) connected in pairs are respectively connected to the interfaces of the two oil ports of the loading cylinder connected in the second integrated block; The outlet of the second overflow valve (22) on the second integrated block is connected to the oil tank assembly (1).

4. The electro-hydraulic servo component hydraulic testing system according to claim 1, characterized in that, The oil supply unit (43) is mounted on the base (46) and includes a first oil inlet filter, a first oil pump motor (4) connected in parallel, a second check valve (5) connected in parallel, and a first pressure pipeline filter (7). The first oil inlet filter, the first oil pump motor (4), the second check valve (5), and the pressure pipeline filter are connected in sequence.

5. The electro-hydraulic servo component hydraulic testing system according to claim 4, characterized in that, The oil replenishment unit (41) is mounted on the base (46) and includes a second inlet filter, a second oil pump motor, a third check valve (31), and a second pressure pipeline filter (30) connected in sequence. The second oil pump motor is connected to the oil tank assembly (1). The outlet of the second oil pump motor is connected to a valve module. The valve module includes a loading overflow valve (32), a solenoid directional valve (27), a second shut-off valve, and a second pressure gauge (28). The outlet of the loading overflow valve (32) is connected to the oil tank. One oil outlet of the valve module is connected to the working port of the solenoid directional valve (27), and the other oil outlet of the valve module is connected to the outlet of the second shut-off valve.

6. The electro-hydraulic servo component hydraulic testing system according to claim 5, characterized in that, An accumulator (3) is provided at the outlet of the oil supply unit. The accumulator (3) group is set on the base (46). The accumulator (3) is also connected to the hydraulic module (40) to maintain a constant oil supply pressure when the oil supply unit switches oil supply sources, to supplement instantaneous flow demand, and to smooth pressure pulsation.

7. The electro-hydraulic servo component hydraulic testing system according to claim 6, characterized in that, The hydraulic module (40) also includes a pressure relay (12), a third pressure gauge (10), and a damper. The pressure relay (12) is used to detect the pressure threshold of the hydraulic test system. When the pressure of the hydraulic test system reaches the set high pressure threshold, the micro switch of the pressure relay (12) is activated. The main control module (42) obtains the signal that the pressure relay (12) activates the micro switch and controls the first oil pump motor (4) or the second oil pump motor to stop. When the pressure of the hydraulic test system drops to the set low pressure threshold, the main control module (42) controls the switching between the oil pump motor groups. The damper is used to smooth the pressure pulse impact in the hydraulic module (40).

8. The electro-hydraulic servo component hydraulic testing system according to claim 6, characterized in that, The oil tank assembly (1) includes an oil tank body, a flow meter (25), a fourth check valve (26), a cooler (35), a temperature relay (37), a solenoid water valve (34), and a return oil filter (29); The temperature relay (37) is located outside the oil tank body and is used to detect the temperature of the oil tank body. The cooler (35) is located on the top surface of the oil tank body. The inlet of the cooler (35) is connected to the return port of the hydraulic module (40). The outlet of the cooler (35) is connected to the flow meter (25) and the fourth check valve (26) in sequence. The electromagnetic water valve (34) is used to control the on / off of the external water supply pump supplying water to the cooler (35). The oil tank body is also equipped with a liquid level control relay (38) for detecting the oil level in the oil tank body. The oil tank body is also equipped with an air filter for maintaining the oil tank body in balance with atmospheric pressure and filtering the air entering the oil tank body.

9. The electro-hydraulic servo component hydraulic testing system according to claim 8, characterized in that, The first pressure line filter (7), the second pressure line filter (30) and the return oil filter (29) are equipped with differential pressure transmitters. The differential pressure transmitters are used to detect the blockage of the first pressure line filter (7), the second pressure line filter (30) and the return oil filter (29) and to alert the main control module (42).

10. A hydraulic testing method for an electro-hydraulic servo component, characterized in that, The hydraulic testing system for electro-hydraulic servo components according to any one of claims 1-9 further includes the following experimental procedures: Setting of test element (15): The test element (15) and the loading cylinder are set at the upper and lower ends of the stand (45), the piston rod of the follower differential cylinder of the test element (15) is connected to the piston rod of the loading cylinder, and a tension and pressure sensor (17) and a follower piston displacement sensor (18) are set between the piston rod of the follower differential cylinder of the test element (15) and the piston rod of the loading cylinder. The valve core position sensor (19) is set on the control valve core of the test element (15). Input of control signals: The control unit of the main control module (42) sends control signals to the hydraulic module (40), the power module and the test element (15); Oil supply and loading of the test element (15): The hydraulic oil in the oil tank is delivered to the P port of the electro-hydraulic directional valve (9) through the first motor oil pump group in the oil supply unit (43). After the electro-hydraulic directional valve (9) is switched to the working left position by power, the valve position remains unchanged. The hydraulic oil flows out from the A port of the electro-hydraulic directional valve (9), passes through the first oil inlet filter and the throttle valve (14) and enters the upper and lower chambers of the follower piston of the test element (15). The up and down movement of the follower piston of the test element (15) and the hydraulic oil pressure difference are controlled by adjusting the magnitude and direction of the input current. As the input current of the control unit gradually increases, the pressure at the variable throttle port on the follower piston increases, and the hydraulic oil pushes the follower piston downward. The hydraulic oil flows back to the oil tank through the T port of the electro-hydraulic directional valve (9), the back pressure valve (8), the flow meter (25), the check valve, and the filter. When the input current gradually decreases to zero, the follower piston stops moving and maintains its current position; at this time, the flow of hydraulic oil is balanced by the oil circuit of the power source, electro-hydraulic directional valve (9), back pressure valve (8) and throttle valve (14) to maintain constant pressure; When the input current increases in the reverse direction, the pressure at the variable throttle port of the follower piston increases, and the hydraulic oil pushes the follower piston upward. The hydraulic oil flows back to the oil tank through the T port of the electro-hydraulic directional valve (9), the back pressure valve (8), the flow meter (25), the check valve, and the filter. Oil replenishment and loading of the loading cylinder: The hydraulic oil in the tank is delivered to the P port of the solenoid directional valve (27) of the loading module (44) via the second motor oil pump group in the loading replenishment power module. After the solenoid directional valve (27) is energized and in the left position, it keeps the valve position unchanged, so that the hydraulic oil flows out from the A port of the solenoid directional valve (27), passes through the loading relief valve (32) and the one-way valve bridge channel in the loading module (44), and replenishes the oil into the forward cavity of the loading cylinder. The piston rod of the loading cylinder moves outward under the drag of the tested electro-hydraulic servo element; at the same time, the hydraulic oil in the retraction cavity of the loading cylinder is squeezed and flows back to the tank through the one-way valve and the loading relief valve (32). During the oil replenishment and loading process, the oil supply pressure of the loading cylinder is set constant by the overflow valve of the power module. The loading overflow valve (32) adjusts the loading pressure of the loading cylinder in real time until the loading pressure reaches the load pressure value required by the test. The main control module (42) monitors the loading pressure value through the control unit. When the electro-hydraulic servo component under test reaches the specified position or the adjusted loading pressure exceeds the actual required value, the loading cylinder stops moving. Acquisition and processing of parameters of the test element (15): The acquisition unit of the main control module (42) acquires the load force signal, piston displacement signal and valve core position signal fed back by the tension and compression sensor (17), the follow-up piston displacement sensor (18) and the valve core position sensor (19) in real time. The processing unit generates various characteristic curves of the test element (15) based on the load force parameter, valve core position parameter, piston displacement parameter and flow parameter obtained from the piston displacement parameter of the test element (15).

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