A hydraulic cylinder sealing tester and test method

Abstract

This invention relates to the field of sealing testing technology, and provides a hydraulic cylinder sealing tester and testing method, including a simulation swing module, an automatic positioning and rotation module, an automatic clamping and docking system, and a load simulation module. The simulation swing module includes a guide rail frame and a first telescopic component. The automatic positioning and rotation module includes a rotating frame, a positioning pin, and a second drive unit. The automatic clamping and docking system includes a second telescopic component, a clamping block, an automatic docking module, and an oil circulation module. The load simulation module includes a sliding housing, a fourth telescopic component, a positioning port, and a displacement sensor. By cleverly utilizing the structural features of the dual-ear hydraulic cylinder, it achieves automatic positioning, automatic docking of the oil port, automatic calibration, and simulated swing under simulated load mode. This solves the problems of existing hydraulic cylinder sealing testing devices that cannot be automated and lack dynamic working condition simulation. It has the characteristics of being suitable for assembly line production, high degree of automation, and high precision.

Description

Technical Field

[0001] This invention relates to the field of sealing testing technology, specifically to a hydraulic cylinder sealing tester and testing method. Background Technology

[0002] Reference Appendix Figure 2 Dual-ear hydraulic cylinders, with hinge holes at both ends, can be used in scenarios that withstand high torque, high impact, and lateral forces. For example, the boom of an excavator is driven by a dual-ear hydraulic cylinder. Good sealing performance ensures that the liquid inside the hydraulic cylinder will not leak or seep out, while preventing external impurities from entering the hydraulic cylinder and ensuring its normal operation. However, when there is aging or damage to the piston seal, damage to the piston rod surface, or improper installation or negligence of hydraulic cylinder components, the sealing performance of the hydraulic cylinder may be weakened. Therefore, it is necessary to perform a sealing test on the hydraulic cylinder before it leaves the factory.

[0003] The differential pressure method is a commonly used test method for hydraulic cylinder sealing. The test principle is that the pressure sensor located on the pipeline connecting the oil and the hydraulic cylinder is connected to the internal chamber of the hydraulic cylinder through a high-pressure pipeline to monitor the real-time pressure changes inside the cylinder.

[0004] A search revealed that CN117804707B discloses a hydraulic cylinder sealing performance testing device, comprising a main frame. A movable groove communicating with its inner cavity is formed at the center of the top of the main frame along the left-right direction. First sliding grooves are formed at both the front and rear ends of the left side of the top of the main frame along the left-right direction. Second sliding grooves are formed at both the front and rear ends of the left side of the top of the inner cavity of the main frame along the left-right direction. The left and right ends of a first guide rod are respectively positioned on the left and right sides of the inner cavity of the movable groove. The left and right ends of a second guide rod are respectively positioned on the left and right sides of the inner cavity of the first sliding groove. While this device can effectively detect the sealing performance of the piston seal, and through comprehensive testing and evaluation of the hydraulic cylinder's sealing performance, it can promptly detect and resolve reduced piston sealing performance, allowing for earlier detection and resolution of oil leakage problems. Furthermore, the pressure gauge and instrument panel provide a more accurate assessment of the hydraulic cylinder's sealing performance, avoiding the problem of unclear observation results. However, it still has the following drawbacks: (1) Traditional hydraulic cylinder sealing test devices are all manually fixed hydraulic cylinders and manually connected oil pipes and oil ports, with low automation level, which cannot be used for automated batch testing needs of production lines; (2) Traditional hydraulic cylinder sealing tests are mostly conducted under static conditions, which cannot simulate the swing motion and axial load under real working conditions. They can usually only test static pressure holding performance or a single dynamic load, and cannot simultaneously simulate the actual motion state of the hydraulic cylinder in engineering machinery (such as excavator boom). Summary of the Invention

[0005] The purpose of this invention is to provide a hydraulic cylinder sealing tester and test method, which aims to solve the problems existing in the current hydraulic cylinder sealing test devices.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a hydraulic cylinder sealing performance tester, comprising a frame, wherein a test panel is disposed inside the frame, and further comprising: The simulation swing module is set on the surface of the test panel. The simulation swing module includes a guide rail and a first telescopic component, which is connected between the guide rail and the test panel. An automatic positioning and rotating module is set on the surface of the test panel. The automatic positioning and rotating module includes a rotating frame, a positioning pin, and a second drive unit. The second drive unit is used to control the rotation of the rotating frame. The rotating frame is fixedly provided with a positioning pin. The positioning pin is used to position one end of the double-ear hydraulic cylinder. The first telescopic member can control the guide rail frame to swing about the positioning pin as the axis. An automatic clamping and docking system includes a second telescopic component, a clamping block, an automatic docking module, and an oil circulation module. The second telescopic component and the clamping block are disposed within a guide rail frame. The second telescopic component is used to control the sliding of the clamping block. The automatic docking module and the oil circulation module are respectively fixedly disposed above the clamping block and the frame. The automatic docking module can be connected to the oil port on the surface of a double-ear hydraulic cylinder. The load simulation module is installed inside the guide rail frame. The load simulation module includes a sliding housing, a fourth telescopic component, a positioning port, and a displacement sensor. The sliding housing is provided with a positioning port and a displacement sensor at both ends, respectively. The fourth telescopic component is used to control the unidirectional sliding of the sliding housing. The piston rod of the double-ear hydraulic cylinder can enter the positioning port.

[0007] A method for testing the sealing performance of a hydraulic cylinder includes: S100. Using a robotic arm, the double-eared hydraulic cylinder on the conveyor line is picked up and transferred to the test station. The ear hole at one end of the double-eared hydraulic cylinder is fitted into the surface of the positioning pin, and the piston rod at the other end of the double-eared hydraulic cylinder enters the positioning port for pre-positioning of the double-eared hydraulic cylinder. S200: The second telescopic component controls the movement of the clamping block and the automatic docking module. When the automatic docking module is not aligned with the oil port, the second telescopic component controls the clamping block to release the double-ear hydraulic cylinder. The second drive unit controls the rotating frame, positioning pin and double-ear hydraulic cylinder to rotate and adjust the tilt angle of the oil port. Under the premise that the automatic docking module is aligned with the oil port, the automatic docking module docks with the oil port. S300: The fourth telescopic component is used to control the sliding housing and piston rod to move toward the clamping block, which is used to calibrate the initial position or axial position of the piston rod. Under the premise that the displacement sensor detects that the initial position of the piston rod has reached the target value, the fourth telescopic component is switched to the non-powered mode. In the non-powered mode, the fourth telescopic component cannot limit the sliding housing. The S400 oil circulation module pressurizes and injects oil into the cylinder cavity through the automatic docking module and oil port. It controls the moving end of the piston rod, sliding housing and fourth telescopic component to move to the preset position. The fourth telescopic component switches to power mode to control the sliding housing to apply reverse pressure F1 to the piston rod to simulate load. After stabilizing the pressure for a preset time, the piston rod coordinate parameters and cylinder pressure parameters are collected. S500: The first telescopic component controls the guide rail frame, the double-ear hydraulic cylinder and the load simulation module to swing around the positioning pin as the axis according to the preset frequency and amplitude. The sealing performance of the double-ear hydraulic cylinder under load F1 is simulated by monitoring the pressure difference parameters during the movement. After the S600 test is completed, the oil in the double-eared hydraulic cylinder is drained using the oil circulation module, the automatic docking module is disconnected from the oil port, and the double-eared hydraulic cylinder is picked up and transferred to the designated position by the robotic arm to realize the automated sealing test of the double-eared hydraulic cylinder.

[0008] The beneficial effects of the present invention are: (1) Based on the test principle of differential pressure method, this application cleverly utilizes the structural features of the double-ear hydraulic cylinder to achieve automatic positioning, automatic docking of oil port, automatic calibration, and simulated swing under simulated load mode. It solves the problems of existing hydraulic cylinder sealing test devices that cannot be automatically tested and lack dynamic working condition simulation. It has the characteristics of being suitable for assembly line production, high degree of automation and high precision.

[0009] (2) This application utilizes the positioning, kinetic energy transmission and rotation axis reuse functions of the fixed pin. On the one hand, it combines the positioning reference and the motion axis into one, avoiding secondary positioning errors that may be introduced by switching the positioning reference and the rotation center. The attitude adjustment of the entire module always revolves around the initial positioning reference, ensuring the installation positioning accuracy, no radial off-center load when the oil port is connected, and the load force and piston rod axis are collinear. On the other hand, it can convert the rotation of the rotating frame into the rotation of the double-ear hydraulic cylinder, which is convenient for adjusting the tilt angle of the oil port in subsequent work, and facilitates the CCD camera module to collect complete image data at the end cover seal. Attached Figure Description

[0010] Figure 1 This is a perspective view of the present invention.

[0011] Figure 2 This is a plan view of a dual-ear hydraulic cylinder in the prior art.

[0012] Figure 3This is an exploded view of the present invention.

[0013] Figure 4 This is a three-dimensional view of the simulation swing module in an embodiment of the present invention.

[0014] Figure 5 This is a perspective view of the automatic positioning and rotation module of the present invention.

[0015] Figure 6 This is a perspective view of the load simulation module in an embodiment of the present invention.

[0016] Figure 7 This is a perspective view of the positioning and docking of the double-ear hydraulic cylinder according to an embodiment of the present invention.

[0017] Figure 8 This is a side view of the positioning and docking of a double-eared hydraulic cylinder according to an embodiment of the present invention.

[0018] Figure 9 For the present invention Figure 8 A magnified view of a portion of point a.

[0019] Figure 10 This is a top view of the positioning and docking of the double-eared hydraulic cylinder according to an embodiment of the present invention.

[0020] Figure 11 This is the front view of the present invention.

[0021] Figure 12 This is a planar sectional view of the present invention at point AA.

[0022] Figure 13 This is a planar sectional view of the present invention at point BB.

[0023] Attached reference numerals: 1-Double-ear hydraulic cylinder, 11-Piston rod, 12-Oil port; 2-Simulation swing module, 21-Guide rail frame, 22-Rotating ring, 23-First telescopic component; 3-Automatic clamping and docking system, 31-Second telescopic component, 32-Clamping block, 33-Tooling frame, 34-Automatic docking module, 341-Internal threaded pipe, 342-First drive unit, 343-Transmission pipe fitting, 344-Key bar, 345-Third telescopic component, 346-Lifting ring, 35-Laser positioning module, 36-Oil circulation module, 37-Oil circuit; 4-Automatic positioning rotary module, 41-Rotating frame, 42-Positioning pin, 43-Second drive unit, 44-Rotating shaft; 5-Load simulation module, 51-Sliding housing, 52-Fourth telescopic component, 53-Positioning port, 54-Accommodation port, 55-Displacement sensor; 6-Control display panel; 7-Rack, 71-Test panel, 72-Frustum, 73-Protective cover, 74-Arc-shaped guide rail; 8-CCD camera module. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0025] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0026] Please see Figures 1 to 13 In one embodiment of the present invention, a hydraulic cylinder sealing tester includes a frame 7 and a control display panel 6. A test panel 71 is disposed inside the frame 7, a frustum 72 is fixedly disposed on the surface of the test panel 71, and a protective cover 73 is fixedly disposed on the surface of the frustum 72. The control display panel 6 is fixedly disposed on the surface of the frame 7 for outputting test results. The tester also includes: The simulation swing module 2 is disposed on the surface of the test panel 71. The simulation swing module 2 includes a guide rail frame 21, a rotating ring 22 and a first telescopic member 23. The rotating ring 22 is disposed at one end of the guide rail frame 21 and is sleeved on the surface of the frustum 72. The guide rail frame 21 and the test panel 71 are both fixedly provided with pins. The two ends of the first telescopic member 23 are respectively rotatably connected to the pins. The surface of the test panel 71 is provided with an arc-shaped guide rail 74. The pin at the guide rail frame 21 is slidably disposed in the arc-shaped guide rail 74. An automatic positioning rotation module 4 is installed on the surface of the test panel 71. The automatic positioning rotation module 4 includes a rotating frame 41, a rotating shaft 44, a positioning pin 42, and a second drive unit 43. The second drive unit 43 is used to control the rotation of the rotating frame 41. The positioning pin 42 is fixedly installed on the surface of the rotating frame 41. The positioning pin 42 is used to position one end of the double-ear hydraulic cylinder 1. The second drive unit 43 is located inside the protective cover 73. The rotating shaft 44 is connected to the side wall of the protective cover 73. The second drive unit 43 includes a worm gear and a driving worm. The driving worm is driven by a drive motor and is used to precisely adjust the rotation angle of the rotating shaft 44. The rotating frame 41 and the worm gear are both fixedly installed on the surface of the rotating shaft 44. The driving worm is connected to the worm gear through a transmission. The first telescopic member 23 can control the guide rail frame 21 to swing about the positioning pin 42 as the axis. The automatic clamping and docking system 3 includes a second telescopic component 31, a clamping block 32, an automatic docking module 34, and an oil circulation module 36. The second telescopic component 31 and the clamping block 32 are disposed in the guide rail frame 21. The second telescopic component 31 is used to control the sliding of the clamping block 32. The automatic docking module 34 and the oil circulation module 36 are respectively fixedly disposed above the clamping block 32 and the frame 7. The automatic docking module 34 can be connected to the oil port 12 on the surface of the double-ear hydraulic cylinder 1. The load simulation module 5 is installed inside the guide rail frame 21. The load simulation module 5 includes a sliding housing 51, a fourth telescopic member 52, a positioning port 53, a receiving port 54, and a displacement sensor 55. The sliding housing 51 has a receiving port 54 on its surface. The other end of the double-eared hydraulic cylinder 1 can be distributed in the receiving port 54. The two ends of the receiving port 54 are respectively provided with the positioning port 53 and the displacement sensor 55. The fourth telescopic member 52 is used to control the unidirectional sliding of the sliding housing 51. The piston rod 11 of the double-eared hydraulic cylinder 1 can enter the positioning port 53. CCD camera modules 8, two sets of CCD camera modules 8 are respectively fixedly installed on the surface of guide rail frame 21 and frustum 72, used to collect image data of end cover of double-ear hydraulic cylinder 1 and piston rod 11, and combine with displacement sensor 55 to accurately locate the position of leakage point relative to piston rod 11.

[0027] In this embodiment of the invention, the first telescopic member 23 and the second telescopic member 31 are both double-acting hydraulic cylinders, and the fourth telescopic member 52 is a single-acting hydraulic cylinder. The single-acting hydraulic cylinder has only one working port 12 (specifically connected to the oil chamber on the retracted side of the piston rod 11), and the oil chamber on the other side (the extended side of the piston rod 11) is directly connected to the atmosphere or the oil tank (through a vent or an open design). The working principle is as follows: when retracting, hydraulic oil is injected into the working port 12, and the pressurized oil pushes the piston to retract the piston rod 11; when extending, the oil pressure is removed. The piston rod 11 is extended by external force (the power of the piston rod 11 when it extends in the double-eared hydraulic cylinder 1 in this application). At this time, the air or oil in the rodless chamber (extended side) is discharged and flows back to the oil tank or into the atmosphere through the vent, which is used to simulate no-load conditions.

[0028] The positioning, kinetic energy transmission and rotation axis 44 of the fixed pin are reused. On the one hand, the positioning reference and the motion axis are combined into one, avoiding secondary positioning errors that may be introduced by switching the positioning reference and the rotation center. The attitude adjustment of the entire module is always around the initial positioning reference, ensuring the installation positioning accuracy, no radial off-center load when the oil port 12 is connected, and the load force is collinear with the axis of the piston rod 11. On the other hand, it can convert the rotation of the rotating frame 41 into the rotation of the double-ear hydraulic cylinder 1, which is convenient for adjusting the tilt angle of the oil port 12 in subsequent work, and facilitates the CCD camera module 8 to collect complete image data at the end cover seal.

[0029] The design of the automatic positioning rotation module 4, the automatic clamping docking system 3, and the load simulation module 5 working together, especially the coaxiality design of the positioning pin 42, the clamping block 32, and the positioning port 53, ensures the positioning of the double-ear hydraulic cylinder 1 from the X / Y direction. On the one hand, it can improve the docking accuracy of the automatic docking module 34 and the oil port 12. On the other hand, it can prevent pressure deviation when applying load to the piston rod 11 through the sliding housing 51, avoid lateral force causing uneven wear of the seal (piston rod 11 and sealing end cap), and facilitate the robot to pick up and put down the double-ear hydraulic cylinder 1.

[0030] Please see Figures 8 to 11 In one embodiment of the present invention, the automatic docking module 34 includes an internally threaded tube 341, a first driving part 342, a transmission tube 343, a key bar 344, a third telescopic member 345, and a lifting ring 346. The internally threaded tube 341 is movably sleeved inside the transmission tube 343. The transmission tube 343 and the internally threaded tube 341 are slidably engaged through the key bar 344 and the keyway. The first driving part 342 is used to control the rotation of the transmission tube 343 and the internally threaded tube 341. The internally threaded tube 341 can be threadedly engaged with the external thread structure of the oil port 12. The lifting ring 346 is connected to the surface of the internally threaded tube 341. The third telescopic member 345 is used to control the movement of the lifting ring 346 and the internally threaded tube 341. The third telescopic member 345 is an electric telescopic rod.

[0031] Please see Figures 7 to 10 Furthermore, the automatic clamping and docking system 3 also includes a tooling frame 33, a laser positioning module 35, and an oil circuit 37. The first drive unit 342, the third telescopic component 345, and the laser positioning module 35 are all fixedly mounted on the surface of the tooling frame 33. The oil circuit 37 is connected between the oil circulation module 36 and the internal threaded pipe 341. The first drive unit 342 includes a drive motor and a drive gear. The transmission pipe 343 includes a rotating pipe and a transmission gear. The transmission gear is fixedly mounted on the surface of the rotating pipe. The rotating pipe is connected to the surface of the tooling frame 33. The drive motor controls the rotation of the rotating pipe through the drive gear and the transmission gear. The laser positioning module 35 is used not only to monitor the position of the oil port 12, but also to monitor the moving distance of the internal threaded pipe 341. When the internal threaded pipe 341 moves downward by a preset distance, the drive motor and the third telescopic component 345 are controlled to stop.

[0032] The oil circulation module 36 includes an oil tank, a hydraulic pump, a proportional pressure valve, a solenoid directional valve, and a pressure sensor. The proportional pressure valve is used to set the test pressure, and the solenoid directional valve is used to switch different oil circuits 37 to inject oil into different oil ports 12. The pressure sensor is used to monitor the pressure change parameters of the internal chamber of the double-ear hydraulic cylinder 1. The proportional pressure valve and the solenoid directional valve realize the switching of multiple oil circuits 37 and precise pressure control. Oil is injected into the rod chamber / rodless chamber through the directional valve to test the sealing performance of the two chambers separately. The dynamic pressure adjustment of the proportional valve can compensate for pressure fluctuations in real time during swinging to ensure stable test pressure.

[0033] In this embodiment of the invention, when the laser positioning module 35 detects that the oil guide port 12 has an excessive tilt angle or offset, it releases the clamping block 32, rotates and adjusts the double-ear hydraulic cylinder 1, and re-clamps it using the clamping block 32 to achieve automatic angle correction of the oil port 12. When the internal threaded tube 341 is aligned with the oil port 12, the third telescopic member 345 is first used to apply pressure to make the thread teeth fit together, and then the first drive unit 342 is used to control the rotation of the transmission tube 343 and the internal threaded tube 341 to avoid thread damage caused by traditional hard tightening and achieve automatic docking.

[0034] A method for testing the sealing performance of a hydraulic cylinder includes: S100. Using a robotic arm, the double-eared hydraulic cylinder 1 on the conveyor line is picked up and transferred to the test station. The ear hole at one end of the double-eared hydraulic cylinder 1 is fitted into the surface of the positioning pin 42, and the piston rod 11 at the other end of the double-eared hydraulic cylinder 1 enters the positioning port 53 for pre-positioning of the double-eared hydraulic cylinder 1. S200. The second telescopic component 31 controls the movement of the clamping block 32 and the automatic docking module 34. The laser positioning module 35 in the automatic docking module 34 measures the tilt angle between the internal threaded tube 341 and the oil port 12. When the tilt angle exceeds the threshold, the second telescopic component 31 controls the clamping block 32 to release the double-eared hydraulic cylinder 1. The second drive unit 43 controls the rotating frame 41, the positioning pin 42 and the double-eared hydraulic cylinder 1 to rotate and adjust the tilt angle of the oil port 12. Under the premise that the tilt angle meets the threshold or the internal threaded tube 341 is aligned with the oil port 12, the first drive unit 342 and the third telescopic component 345 are activated. The third telescopic component 345 is used to apply pre-pressure to the internal threaded tube 341 so that the internal threaded tube 341 can contact the threaded structure at the oil port 12. The first drive unit 342 is used to control the rotation of the internal threaded tube 341. Under the downward pressure provided by the third telescopic component 345, the internal threaded tube 341 can be spirally fixed to the threaded structure at the oil port 12, thereby completing the automatic docking of the oil port 12. S300. The fourth telescopic component 52 is used to control the sliding housing 51 and the piston rod 11 to move toward the clamping block 32. This is used to calibrate the initial position or axial position of the piston rod 11 (if the piston rod 11 is not in the designed initial position or has not returned to zero, it will cause the volume of the test chamber to change, affecting the pressure change rate and sealing test results during pressurization). Under the premise that the displacement sensor 55 monitors that the initial position of the piston rod 11 has reached the target value, the fourth telescopic component 52 is switched to the non-powered mode. In the non-powered mode, the fourth telescopic component 52 cannot limit the sliding housing 51. S400: The hydraulic pump pressurizes the oil in the tank into the cylinder cavity through the oil passage 37, the internal threaded pipe 341 and the oil port 12. This is used to control the moving ends of the piston rod 11, the sliding housing 51 and the fourth telescopic member 52 to move to the preset position. The fourth telescopic member 52 is used to switch to the power mode to control the sliding housing 51 to apply a reverse pressure F1 to the piston rod 11 to simulate the load. After stabilizing the pressure for a preset time, the coordinate parameters of the piston rod 11 (displacement sensor 55) and the cylinder pressure parameters (pressure sensor) are collected. S500: Using the first telescopic component 23, the guide rail frame 21, the double-ear hydraulic cylinder 1, and the load simulation module 5 are controlled to swing around the positioning pin 42 at a preset frequency and amplitude for a certain period of time and then reset. After a certain period of stillness, the pressure sensor monitors the pressure difference parameters during the movement to determine whether there is a leak. If a leak is confirmed, the CCD camera module 8 is used to collect image data of the leak point (the location of the leak point includes the hydraulic cylinder end cover and the piston rod 11), thereby simulating the sealing performance of the double-ear hydraulic cylinder 1 under load F1. S600 After the test is completed, the oil in the double-eared hydraulic cylinder 1 is drained using the oil circulation module 36. In step S200, the internal threaded pipe 341 is disconnected from the oil port 12. The double-eared hydraulic cylinder 1 is then picked up and transferred to a designated position using a robotic arm to achieve automated sealing testing of the double-eared hydraulic cylinder 1.

[0035] In summary, this application, based on the pressure difference method, cleverly utilizes the structural features of the double-ear hydraulic cylinder 1 to achieve automatic positioning, automatic docking with the oil port 12, automatic calibration, and simulated swinging under simulated load mode. It solves the problems of existing hydraulic cylinder sealing test devices that cannot be automated and lack dynamic working condition simulation. It has the characteristics of being suitable for assembly line production, high degree of automation, and high precision.

[0036] While several embodiments and examples of the present invention have been described for those skilled in the art, these embodiments and examples are provided as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention.

[0037] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A hydraulic cylinder sealing performance tester, comprising a frame (7), wherein a test panel (71) is disposed inside the frame (7), characterized in that, Also includes: The simulation swing module (2) is set on the surface of the test panel (71). The simulation swing module (2) includes a guide rail frame (21) and a first telescopic member (23). The first telescopic member (23) is connected between the guide rail frame (21) and the test panel (71). An automatic positioning rotation module (4) is set on the surface of the test panel (71). The automatic positioning rotation module (4) includes a rotating frame (41), a positioning pin (42), and a second drive unit (43). The second drive unit (43) is used to control the rotation of the rotating frame (41). The rotating frame (41) is fixedly provided with a positioning pin (42). The positioning pin (42) is used to position one end of the double-ear hydraulic cylinder (1). The first telescopic member (23) can control the guide rail frame (21) to swing around the positioning pin (42) as the axis. An automatic clamping docking system (3) includes a second telescopic component (31), a clamping block (32), an automatic docking module (34), and an oil circulation module (36). The second telescopic component (31) and the clamping block (32) are disposed in the guide rail frame (21). The second telescopic component (31) is used to control the sliding of the clamping block (32). The automatic docking module (34) and the oil circulation module (36) are respectively fixedly disposed above the clamping block (32) and the frame (7). The automatic docking module (34) can be connected to the oil port (12) on the surface of the double-ear hydraulic cylinder (1). The load simulation module (5) is installed in the guide rail frame (21). The load simulation module (5) includes a sliding housing (51), a fourth telescopic member (52), a positioning port (53), and a displacement sensor (55). The sliding housing (51) has a positioning port (53) and a displacement sensor (55) at both ends. The fourth telescopic member (52) is used to control the sliding housing (51) to slide in one direction. The piston rod (11) of the double-ear hydraulic cylinder (1) can enter the positioning port (53).

2. The hydraulic cylinder sealing performance tester according to claim 1, characterized in that, The automatic docking module (34) includes an internally threaded tube (341), a first drive unit (342), a transmission tube (343), a key bar (344), a third telescopic member (345), and a lifting ring (346). The internally threaded tube (341) is movably sleeved inside the transmission tube (343). The transmission tube (343) and the internally threaded tube (341) are slidably engaged through the key bar (344) and the keyway. The first drive unit (342) is used to control the rotation of the transmission tube (343) and the internally threaded tube (341). The internally threaded tube (341) can be threadedly engaged with the external thread structure of the oil port (12). The lifting ring (346) is connected to the surface of the internally threaded tube (341). The third telescopic member (345) is used to control the movement of the lifting ring (346) and the internally threaded tube (341).

3. The hydraulic cylinder sealing performance tester according to claim 2, characterized in that, The automatic clamping and docking system (3) also includes a tooling frame (33), a laser positioning module (35), and an oil circuit (37). The first drive unit (342), the third telescopic component (345), and the laser positioning module (35) are all fixedly mounted on the surface of the tooling frame (33). The oil circuit (37) is connected between the oil circulation module (36) and the internal threaded pipe (341). The laser positioning module (35) is used to monitor the position of the oil port (12).

4. The hydraulic cylinder sealing performance tester according to claim 3, characterized in that, The oil circulation module (36) includes an oil tank, a hydraulic pump, a proportional pressure valve, a solenoid directional valve and a pressure sensor. The proportional pressure valve is used to set the test pressure. The solenoid directional valve is used to switch different oil circuits (37) to inject oil into different oil ports (12). The pressure sensor is used to monitor the pressure change parameters of the internal chamber of the double-ear hydraulic cylinder (1).

5. A hydraulic cylinder sealing performance tester according to claim 1, characterized in that, A frustum (72) is fixedly disposed on the surface of the test panel (71), and a protective cover (73) is fixedly disposed on the surface of the frustum (72). The second drive unit (43) is located inside the protective cover (73).

6. A hydraulic cylinder sealing performance tester according to claim 5, characterized in that, The simulation swing module (2) also includes a rotating ring (22), which is disposed at one end of the guide rail frame (21) and is sleeved on the surface of the frustum (72).

7. A hydraulic cylinder sealing performance tester according to claim 5, characterized in that, Both the guide rail frame (21) and the test panel (71) are fixedly provided with pins. The two ends of the first telescopic member (23) are rotatably connected to the pins. The surface of the test panel (71) is provided with an arc-shaped guide rail (74). The pin at the guide rail frame (21) is slidably provided in the arc-shaped guide rail (74).

8. A hydraulic cylinder sealing performance tester according to claim 5, characterized in that, The automatic positioning rotation module (4) also includes a rotating shaft (44), which is connected to the side wall of the protective cover (73). The second drive unit (43) includes a worm gear and a driving worm. The rotating frame (41) and the worm gear are both fixedly mounted on the surface of the rotating shaft (44), and the driving worm is connected to the worm gear in a transmission.

9. A hydraulic cylinder sealing performance tester according to claim 5, characterized in that, It also includes a CCD camera module (8), with the two sets of CCD camera modules (8) fixedly mounted on the guide rail frame (21) and the frustum (72) respectively, for acquiring image data of the end cap and piston rod (11) of the double-eared hydraulic cylinder (1).

10. A method for testing the sealing performance of a hydraulic cylinder, applied to a hydraulic cylinder sealing tester according to any one of claims 1-9, characterized in that, include: S100. Using a robotic arm, the double-eared hydraulic cylinder (1) on the conveyor line is picked up and transferred to the test station. The ear hole at one end of the double-eared hydraulic cylinder (1) is fitted into the surface of the positioning pin (42), and the piston rod (11) at the other end of the double-eared hydraulic cylinder (1) is inserted into the positioning port (53) for pre-positioning of the double-eared hydraulic cylinder (1). S200. The second telescopic component (31) controls the movement of the clamping block (32) and the automatic docking module (34). When the automatic docking module (34) is not aligned with the oil port (12), the second telescopic component (31) controls the clamping block (32) to release the double-ear hydraulic cylinder (1). The second drive unit (43) controls the rotating frame (41), the positioning pin (42) and the double-ear hydraulic cylinder (1) to rotate and adjust the tilt angle of the oil port (12). Under the premise that the automatic docking module (34) is aligned with the oil port (12), the automatic docking module (34) docks with the oil port (12). S300. The fourth telescopic component (52) is used to control the sliding housing (51) and piston rod (11) to move toward the clamp (32) for calibration of the initial position or axial position of piston rod (11). Under the premise that the displacement sensor (55) monitors that the initial position of piston rod (11) has reached the target value, the fourth telescopic component (52) is switched to the non-powered mode. In the non-powered mode, the fourth telescopic component (52) cannot limit the sliding housing (51). S400, the oil circulation module (36) pressurizes and injects oil into the cylinder cavity through the automatic docking module (34) and the oil port (12), which is used to control the moving ends of the piston rod (11), the sliding housing (51) and the fourth telescopic component (52) to move to the preset position. The fourth telescopic component (52) is used to switch to the power mode, which is used to control the sliding housing (51) to apply reverse pressure F1 to the piston rod (11) to simulate the load. After stabilizing the pressure for a preset time, the coordinate parameters of the piston rod (11) and the cylinder pressure parameters are collected. S500, using the first telescopic component (23) to control the guide rail frame (21), the double-ear hydraulic cylinder (1) and the load simulation module (5) to swing around the positioning pin (42) as the axis according to the preset frequency and amplitude, and to simulate the sealing performance of the double-ear hydraulic cylinder (1) under load F1 by monitoring the pressure difference parameters during the movement. S600 After the test is completed, the oil in the double-eared hydraulic cylinder (1) is drained by the oil circulation module (36), the automatic docking module (34) is disconnected from the oil port (12), and the double-eared hydraulic cylinder (1) is picked up and transferred to the designated position by the robot arm to realize the automated sealing test of the double-eared hydraulic cylinder (1).

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