Test system for hydraulic cylinder

Abstract

The invention provides a hydraulic test system for a hydraulic cylinder, and the system comprises an oil tank which stores hydraulic oil; an input oil path of the first main pump is communicated with the oil tank; the first main oil way reversing pressure regulating valve group is communicated with an output oil way of the first main pump; an input oil path of the second main pump is communicated with the oil tank; the second main oil way reversing pressure regulating valve group is communicated with the output oil way of the second main pump, and a flow collecting valve is arranged between the output oil way of the first main pump and the output oil way of the second main pump; wherein the rated displacement of the first main pump is configured to be smaller than the rated displacement of the second main pump, and the oil path drift diameter of the first main oil path reversing pressure regulating valve group is smaller than the oil path drift diameter of the second main oil path reversing pressure regulating valve group, so that at least two tested hydraulic cylinders with different specifications are connected.

Description

Technical Field

[0001] At least one embodiment of this disclosure relates to the field of hydraulic system technology, and more specifically, to a testing system for hydraulic cylinders. Background Technology

[0002] As a key hydraulic actuator, the performance testing of hydraulic cylinders before they leave the factory is crucial. Currently, testing equipment for hydraulic cylinders has two main limitations.

[0003] On the one hand, current mainstream testing systems typically employ a fixed flow rate and a single hydraulic circuit design, making it difficult to adapt to the testing needs of hydraulic cylinders of different sizes. Specifically, testing small-sized hydraulic cylinders easily leads to energy waste and difficulty in precision control, while when dealing with large-diameter, long-stroke hydraulic cylinders, insufficient flow results in excessively long filling and testing cycles, leading to low efficiency.

[0004] On the other hand, many test benches are still designed as single-path, single-station systems, which makes it impossible to install and test multiple hydraulic cylinders in parallel and synchronously. In large-volume testing scenarios, the serial testing mode becomes an efficiency bottleneck, and manual intervention introduces errors, affecting the consistency and reliability of the test. Summary of the Invention

[0005] To address at least one of the above-mentioned and other technical problems in the related art, this disclosure provides a testing system for hydraulic cylinders to at least partially solve the above-mentioned technical problems.

[0006] This disclosure provides a hydraulic testing system for hydraulic cylinders, comprising: an oil tank storing hydraulic oil; a first main pump, the input oil circuit of which is connected to the oil tank; a first main oil circuit reversing and pressure regulating valve assembly connected to the output oil circuit of the first main pump; a second main pump, the input oil circuit of which is connected to the oil tank; and a second main oil circuit reversing and pressure regulating valve assembly connected to the output oil circuit of the second main pump. A confluence valve is provided between the output oil circuits of the first and second main pumps. The rated displacement of the first main pump is configured to be less than the rated displacement of the second main pump, and the oil circuit diameter of the first main oil circuit reversing and pressure regulating valve assembly is less than the oil circuit diameter of the second main oil circuit reversing and pressure regulating valve assembly, to connect at least two hydraulic cylinders of different specifications to be tested.

[0007] According to an embodiment of this disclosure, the testing system further includes: at least two sets of hydraulic cylinder interface integration blocks, each set of the hydraulic cylinder interface integration blocks including an A-port integration block and a B-port integration block, and each of the A-port integration blocks and the B-port integration blocks being provided with multiple quick-release interfaces.

[0008] According to embodiments of this disclosure, at least two sets of hydraulic cylinder interface integration blocks include: a first hydraulic cylinder A port integration multi-pass block and a first hydraulic cylinder B port integration multi-pass block to form a first test branch; and a second hydraulic cylinder A port integration multi-pass block and a second hydraulic cylinder B port integration multi-pass block to form a second test branch; wherein the first test branch and / or the second test branch are configured to connect the hydraulic cylinders under test in parallel through the quick-release interface.

[0009] According to embodiments of this disclosure, the first main oil circuit reversing pressure regulating valve group and / or the second main oil circuit reversing pressure regulating valve group are configured to have at least a first state, a second state, and a third state. In the first state, the P port of the first main oil circuit reversing pressure regulating valve group and / or the second main oil circuit reversing pressure regulating valve group is connected to the PA1 port, and the PB1 port is connected to the T port, so as to drive the piston rod of the hydraulic cylinder under test to extend. In the second state, the P port of the first main oil circuit reversing pressure regulating valve group and / or the second main oil circuit reversing pressure regulating valve group is connected to the PB1 port, and the PA1 port is connected to the T port, so as to drive the piston rod of the hydraulic cylinder under test to retract. In the third state, the P port, PA1 port, PB1 port, and T port of the first main oil circuit reversing pressure regulating valve group and / or the second main oil circuit reversing pressure regulating valve group are mutually disconnected, so that the hydraulic cylinder under test is held in a predetermined position.

[0010] According to an embodiment of this disclosure, a first bypass electro-proportional relief valve is provided on the bypass of the first main oil circuit reversing pressure regulating valve group, and a second bypass electro-proportional relief valve is provided on the bypass of the second main oil circuit reversing pressure regulating valve group; wherein, the first bypass electro-proportional relief valve and the second bypass electro-proportional relief valve are configured to, during the start-up pressure test, respectively cooperate with the electro-proportional pilot loading valve in the first main oil circuit reversing pressure regulating valve group or the second main oil circuit reversing pressure regulating valve group to perform pressure compensation regulation.

[0011] According to embodiments of this disclosure, the first main oil circuit reversing pressure regulating valve group includes a second cartridge valve, a third cartridge valve, a fourth cartridge valve, a fifth cartridge valve, a first pilot on / off valve, and a second pilot on / off valve. In the first state, the first pilot on / off valve is de-energized, the third and fifth cartridge valves are closed, the second pilot on / off valve is energized, and the second and fourth cartridge valves are open. In the second state, the first pilot on / off valve is energized, the third and fifth cartridge valves are open, the second pilot on / off valve is de-energized, and the second and fourth cartridge valves are closed. In the third state, both the first and second pilot on / off valves are de-energized, and the second, third, fourth, and fifth cartridge valves are all closed.

[0012] According to an embodiment of this disclosure, the testing system further includes a first main oil circuit flow metering safety valve group; the first oil outlet of the first main oil circuit flow metering safety valve group is connected to the oil inlet of the first main oil circuit reversing pressure regulating valve group to provide a pressure oil source for the oil inlet of the first main oil circuit reversing pressure regulating valve group; the second oil outlet of the first main oil circuit flow metering safety valve group is connected to the oil inlet of a first bypass proportional relief valve through a first ball valve; wherein, the first bypass proportional relief valve is configured to work in conjunction with the first main oil circuit reversing pressure regulating valve group when the first ball valve is opened to regulate the system pressure of the first test branch.

[0013] According to embodiments of this disclosure, the second main oil circuit reversing pressure regulating valve group includes a second cartridge valve, a third cartridge valve, a fourth cartridge valve, a fifth cartridge valve, a first pilot on / off valve, and a second pilot on / off valve.

[0014] In the first state described above, the first pilot shut-off valve is not energized, the third and fifth cartridge valves are closed, the second pilot shut-off valve is energized, and the second and fourth cartridge valves are open. In the second state described above, the first pilot shut-off valve is energized, the third and fifth cartridge valves are open, the second pilot shut-off valve is not energized, the second and fourth cartridge valves are closed, and the third and fifth cartridge valves are open. In the third state described above, both the first and second pilot shut-off valves are not energized, and the second, third, fourth, and fifth cartridge valves are all closed.

[0015] According to an embodiment of this disclosure, the third outlet of the first main oil circuit flow metering safety valve group is connected to the inlet of the second main oil circuit reversing pressure regulating valve group to provide a pressure oil source for the second main oil circuit reversing pressure regulating valve group; the fourth outlet of the first main oil circuit flow metering safety valve group is connected to the inlet of the second bypass electro-proportional relief valve through the second ball valve; wherein, the second bypass electro-proportional relief valve is configured to work in conjunction with the second main oil circuit reversing pressure regulating valve group when the second ball valve is opened to regulate the system pressure of the second test branch.

[0016] According to an embodiment of this disclosure, the inlet of the first main oil circuit flow metering safety valve group is connected to the output oil circuit of the first main pump and / or the second main pump, and the outlet of the first main oil circuit flow metering safety valve group is connected to the inlet of the first main oil circuit reversing pressure regulating valve group and / or the second main oil circuit reversing pressure regulating valve group; the first main oil circuit flow metering safety valve group includes a valve block, a first safety protection unit and a second safety protection unit in parallel; the first safety protection unit includes a first two-way loading cartridge valve, a first pilot loading valve for setting a pilot pressure for the first two-way loading cartridge valve, and a first pressure shut-off valve connected in parallel with the first pilot loading valve, the first safety protection unit being used for the first main oil circuit reversing pressure regulating valve group. The pressure valve assembly provides a pressure oil source and sets a maximum safe pressure; the second safety protection unit includes a second two-way loading cartridge valve, a second pilot loading valve for setting a pilot pressure for the second two-way loading cartridge valve, and a second pressure shut-off valve connected in parallel with the second pilot loading valve. The second safety protection unit is used to provide a pressure oil source and set a maximum safe pressure for the second main oil circuit reversing pressure regulating valve assembly; the first main oil circuit flow metering safety valve assembly also integrates a first flow meter and a first pressure sensor, configured to monitor the flow rate and pressure of the oil flowing to the first main oil circuit reversing pressure regulating valve assembly; and a second flow meter and a second pressure sensor, configured to monitor the flow rate and pressure of the oil flowing to the second main oil circuit reversing pressure regulating valve assembly.

[0017] According to an embodiment of this disclosure, the first main oil circuit flow metering safety valve group further includes a first internally controlled cartridge valve and a second internally controlled cartridge valve; the control chambers of the first internally controlled cartridge valve and the second internally controlled cartridge valve are connected to a control oil circuit and the corresponding main oil circuit; the first internally controlled cartridge valve and the second internally controlled cartridge valve are configured to use the higher pressure between the control oil pressure and the main oil circuit pressure as the effective control pressure.

[0018] According to embodiments of this disclosure, the first main oil circuit reversing pressure regulating valve group further includes a first cartridge valve and a sixth cartridge valve; the first cartridge valve is connected between the first oil outlet and the first oil return port of the valve block, and the sixth cartridge valve is connected between the second oil outlet and the first oil return port of the valve block; when the valve group is in the third state, both the first cartridge valve and the sixth cartridge valve are configured to be closed to disconnect the connection between the first oil outlet and the second oil outlet and the oil return circuit; the test system further includes multiple sets of measuring cylinders, each set of measuring cylinders being connected to the oil return branch of the first hydraulic cylinder A port integrated multi-pass block or the first hydraulic cylinder B port integrated multi-pass block through an independent leakage measuring valve; and / or, the second main oil circuit reversing pressure regulating valve group further includes a first cartridge valve and a sixth cartridge valve; the first The cartridge valve is connected between port A and the return port of the valve block, and the sixth cartridge valve is connected between port B and the return port of the valve block. When the valve group is in the third state, both the first and sixth cartridge valves are controlled to be closed to cut off the connection between ports A and B and the return oil circuit. The test system also includes multiple sets of measuring cylinders (each set of measuring cylinders can be adapted to different specifications of the hydraulic cylinders under test). Each set of measuring cylinders is connected to the return oil branch of the integrated multi-pass block at port A of the second hydraulic cylinder or the integrated multi-pass block at port B of the second hydraulic cylinder through an independent leakage measuring valve. When performing an internal leakage test, the corresponding leakage measuring valve is opened so that the oil leaking from the piston of the hydraulic cylinder under test is directly guided to the corresponding measuring cylinder for volume measurement.

[0019] According to embodiments of this disclosure, when the first main oil circuit reversing pressure regulating valve group is in the third state, the second, third, fourth, fifth, first, and sixth cartridge valves are all closed, so as to achieve complete isolation of all working ports from the pressure source, return port, and pilot control oil circuit within the valve group; and / or, when the second main oil circuit reversing pressure regulating valve group is in the third state, the second, third, fourth, fifth, first, and sixth cartridge valves are all closed, so as to achieve complete isolation of all working ports from the pressure source, return port, and pilot control oil circuit within the valve group.

[0020] According to embodiments of this disclosure, the first hydraulic cylinder A-port integrated multi-port block and the first hydraulic cylinder B-port integrated multi-port block each have three independent leakage measurement branches corresponding to three quick-release interfaces; each of the above leakage measurement branches includes a leakage measurement valve and a measuring cylinder arranged in series; the leakage measurement branch is connected between the corresponding quick-release interface and the system return oil circuit, and the leakage measurement valve is located upstream of the measuring cylinder; and / or, the second hydraulic cylinder A-port integrated multi-port block and the second hydraulic cylinder B-port integrated multi-port block each have three independent leakage measurement branches corresponding to three quick-release interfaces; each of the above leakage measurement branches includes a leakage measurement valve and a measuring cylinder arranged in series; the leakage measurement branch is connected between the corresponding quick-release interface and the system return oil circuit, and the leakage measurement valve is located upstream of the measuring cylinder.

[0021] According to an embodiment of this disclosure, the testing system further includes: a first control pump, the input oil circuit of which is connected to the oil tank for providing a control oil source; a first control oil pressure regulating safety valve group, which is connected to the output oil circuit of the first control pump for regulating and providing stable control oil; and an accumulator, which is connected to the control oil circuit provided by the first control oil pressure regulating safety valve group.

[0022] According to the hydraulic cylinder testing system provided in this disclosure, two independent testing channels with tiered performance parameters are constructed by setting up a first main pump and a second main pump with different rated displacements, and a first main oil circuit reversing and pressure regulating valve group and a second main oil circuit reversing and pressure regulating valve group with different oil circuit diameters. Based on this, for small-sized hydraulic cylinders under test, a channel consisting of a small-displacement pump and a small-diameter valve group can be used, whose output flow is more matched to the testing requirements, reducing overflow losses and facilitating fine flow adjustment and pressure stability. For large-sized hydraulic cylinders under test, a channel consisting of a large-displacement pump and a large-diameter valve group can be used, whose sufficient flow can significantly shorten filling and running time, improving testing efficiency. Furthermore, the merging valve between the two channels can combine the outputs of the first and second main pumps when needed to provide a larger peak flow rate to meet the testing requirements of larger-sized hydraulic cylinders. In this way, the testing system can select the appropriate working mode according to the specifications of the object being tested, thereby solving the problems of high energy consumption, difficulty in precision control, or low efficiency of single-specification testing systems in related technologies when adapting to hydraulic cylinders of different sizes. Attached Figure Description

[0023] Figure 1 This is a hydraulic schematic diagram of a hydraulic cylinder testing system according to an illustrative embodiment of the present disclosure;

[0024] Figure 2 yes Figure 1The diagram shows the hydraulic schematic of the main oil circuit flow metering safety valve assembly in the hydraulic cylinder test system.

[0025] Figure 3 yes Figure 1 The diagram shows the hydraulic schematic of the control oil pressure regulating safety valve assembly in the hydraulic cylinder test system.

[0026] Figure 4 yes Figure 1 The hydraulic schematic diagram of the first main oil circuit reversing pressure regulating valve group in the hydraulic cylinder test system is shown.

[0027] Figure 5 yes Figure 1 The diagram shows the hydraulic principle of the second main oil circuit reversing pressure regulating valve group in the hydraulic cylinder test system.

[0028] In the accompanying drawings, the meanings of the reference numerals are as follows:

[0029] 1. Oil tank; 2. First control pump; 3. First main pump; 4. Second main pump; 5. First circulation pump; 6. First control oil check valve; 7. First check valve; 8. Second check valve; 9. First filter; 10. Second filter; 11. Third filter;

[0030] 12. First main oil circuit flow metering safety valve assembly; 121. Valve block; 1212. First two-way loading cartridge valve; 1213. First pilot loading valve; 1214. First pressure shut-off valve; 1216. Second two-way loading cartridge valve; 1217. Second pilot loading valve; 1218. Second pressure shut-off valve; 1219. First flow meter; 1220. Second flow meter; 1221. First pressure sensor; 1222. Second pressure sensor; 1223. First internal control cartridge valve; 1224. Second internal control cartridge valve;

[0031] 13. First control oil pressure regulating safety valve assembly; 131. First control oil pressure regulating safety valve block; 1311. First control oil safety valve; 1312. First control oil pressure reducing valve; 1313. First control oil pressure sensor; 1314. Second control oil pressure sensor;

[0032] 14. First ball valve; 15. First bypass proportional relief valve; 16. Second ball valve; 17. Second bypass proportional relief valve;

[0033] 18. First main oil circuit reversing pressure regulating valve group; 1811. First cartridge valve; 1812. Second cartridge valve; 1813. Third cartridge valve; 1814. Fourth cartridge valve; 1815. Fifth cartridge valve; 1816. Sixth cartridge valve; 1817. Seventh cartridge valve; 1818. Eighth cartridge valve; 1819. First main oil circuit 16-channel electro-proportional loading module; 1820. First mechanical pilot loading valve; 1821. First electro-proportional pilot loading valve; 1822. First pilot on / off valve; 1823. Second pilot on / off valve; 1824. Third pilot on / off valve; 1825. Fourth pilot on / off valve;

[0034] 19. Second main oil circuit reversing pressure regulating valve assembly; 191. First main oil circuit 32-port reversing pressure regulating valve block; 1911. First cartridge valve; 1912. Second cartridge valve; 1913. Third cartridge valve; 1914. Fourth cartridge valve; 1915. Fifth cartridge valve; 1916. Sixth cartridge valve; 1917. Seventh cartridge valve; 1918. First main oil circuit 32-port electro-proportional loading module; 1919. First electro-proportional pilot loading valve; 1920. Second electro-proportional pilot loading valve; 1921. First pilot on / off valve; 1922. Second pilot on / off valve; 1923. Third pilot on / off valve; 1924. Fourth pilot on / off valve;

[0035] 20. First ball valve; 21. Second ball valve; 22. Accumulator; 23. Third ball valve; 24. Fourth ball valve; 25. First hydraulic cylinder A-port integrated multi-port block; 26. First hydraulic cylinder A-port integrated block pressure sensor; 27. Fifth ball valve; 28. Quick-release interface; 29. ​​First hydraulic cylinder stroke detection sensor; 30. First hydraulic cylinder; 31. Quick-release interface; 32. Sixth ball valve; 33. First measuring cylinder; 34. Quick-release interface; 35. Second hydraulic cylinder 36. Second hydraulic cylinder; 37. Quick-release interface; 38. Seventh ball valve; 39. Second measuring cylinder; 40. Quick-release interface; 41. Third hydraulic cylinder stroke detection sensor; 42. Third hydraulic cylinder under test; 43. Quick-release interface; 44. Eighth ball valve; 45. Third measuring cylinder; 46. First hydraulic cylinder B port integrated multi-port block; 47. Ninth ball valve; 48. First hydraulic cylinder B port integrated block pressure sensor; 49. Second hydraulic cylinder A port integrated block... 50. Multi-channel block; 51. Pressure sensor of the second hydraulic cylinder A port integrated block; 52. Quick-release interface; 53. Stroke detection sensor of the fourth hydraulic cylinder; 54. Fourth measuring hydraulic cylinder; 55. Quick-release interface; 56. Leakage measuring valve; 57. Measuring cylinder; 58. Quick-release interface; 59. Stroke detection sensor of the fifth hydraulic cylinder; 60. Quick-release interface; 61. Leakage measuring valve; 62. Measuring cylinder; 63. Quick-release interface; 64. Stroke of the sixth hydraulic cylinder Detection sensor; 65. Sixth hydraulic cylinder under test; 66. Quick-release interface; 67. Leakage measuring valve; 68. Measuring cylinder; 69. Thirteenth ball valve; 70. Second hydraulic cylinder B-port integrated multi-port block; 71. Second hydraulic cylinder B-port integrated block pressure sensor; 72. Fourteenth ball valve; 73. Fifteenth ball valve; 74. Sixteenth ball valve; 75. Seventeenth ball valve; 76. Confluence valve; 77. First return oil multi-port block; 78. Fourth filter; 79. First oil cooler; Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0037] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0038] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0039] When using expressions such as "at least one of A, B, and C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C. Similarly, when using expressions such as "at least one of A, B, or C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C.

[0040] Figure 1 This is a hydraulic schematic diagram of a hydraulic cylinder testing system according to an illustrative embodiment of the present disclosure. Oil tank.

[0041] This disclosure provides a testing system for hydraulic cylinders, with reference to... Figure 1 As shown, the system includes an oil tank 1, a first main pump 3, a second main pump 4, a first main oil circuit reversing pressure regulating valve group 18, and a second main oil circuit reversing pressure regulating valve group 19. The oil tank 1 stores hydraulic oil. The input oil circuit of the first main pump 3 is connected to the oil tank 1. The input oil circuit of the second main pump 4 is also connected to the oil tank 1. The first main oil circuit reversing pressure regulating valve group 18 is connected to the output oil circuit of the first main pump 3. The second main oil circuit reversing pressure regulating valve group 19 is connected to the output oil circuit of the second main pump 4. A confluence valve 76 is provided between the output oil circuits of the first main pump 3 and the second main pump 4. The rated displacement of the first main pump 3 is configured to be less than the rated displacement of the second main pump 4, and the oil circuit diameter of the first main oil circuit reversing pressure regulating valve group 18 is smaller than the oil circuit diameter of the second main oil circuit reversing pressure regulating valve group 19, to connect at least two hydraulic cylinders of different specifications under test.

[0042] According to embodiments of this disclosure, referring to Figure 1 As shown, the test system also includes a first main oil circuit flow metering safety valve assembly 12. The first outlet PA1 of the first main oil circuit flow metering safety valve assembly 12 is connected to the inlet of the first main oil circuit reversing pressure regulating valve assembly 18 to provide a pressure oil source for the inlet of the first main oil circuit reversing pressure regulating valve assembly 18. The second outlet PA2 of the first main oil circuit flow metering safety valve assembly 12 is connected to the inlet of the first bypass electro-proportional relief valve 15 via a first ball valve 14. The first bypass electro-proportional relief valve 15 is configured to work in conjunction with the first main oil circuit reversing pressure regulating valve assembly 18 when the first ball valve 14 is open to regulate the system pressure of the first test branch.

[0043] In some illustrative embodiments, reference is made to Figure 1As shown, the suction ports of the first control pump 2, the first main pump 3, and the second main pump 4 draw hydraulic oil from the oil tank 1 via suction hoses, among others. Furthermore, to prevent backflow of oil, each pump's outlet is connected in series with a check valve. Specifically, the outlet of the first control pump 2 is connected to the first control oil check valve 6, the outlet of the first main pump 3 is connected to the first check valve 7, and the outlet of the second main pump 4 is connected to the second check valve 8.

[0044] Furthermore, to ensure oil cleanliness, each main oil circuit is equipped with an independent filtration system. Specifically, the outlet of the first control oil check valve 6 is connected to the inlet P of the first filter 9 via a hydraulic hose; the outlet of the first check valve 7 is connected to the P of the second filter 10; and the outlet of the second check valve 8 is connected to the P of the third filter 11. After filtration, the outlet A of the second filter 10 and the third filter 11, which supply oil to the main oil circuit, are respectively connected via steel pipes to the corresponding inlets P1 and P2 of the first main oil circuit flow metering safety valve assembly 12, thus providing a clean and directionally controlled pressure oil source for the testing process.

[0045] In some illustrative embodiments, reference is made to Figure 1 As shown, the first control oil pressure regulating safety valve assembly 13 is responsible for providing a stable system control oil. Specifically, the inlet Px of the first control oil pressure regulating safety valve assembly 13 is connected to the outlet A of the first filter 9 via a steel pipe, receiving oil from the first control pump 2. The first control oil pressure regulating safety valve assembly 13 has multiple outputs. Its first outlet Pc is connected to the control port Pk of the first main oil circuit flow metering safety valve assembly 12 via a steel pipe, providing it with the required control oil pressure. Its second outlet Px1 and third outlet Px2 are respectively connected to the control ports X of the first main oil circuit reversing pressure regulating valve assembly 18 and the second main oil circuit reversing pressure regulating valve assembly 19 via steel pipes, providing power for the pilot reversing of these two valve assemblies. Furthermore, the first control oil pressure reducing valve 1312 integrated in the first control oil pressure regulating safety valve assembly 13 has an electro-proportional function, capable of receiving remote electrical signals, thereby achieving remote, continuous, and precise stepless setting of the output control oil pressure.

[0046] In some illustrative embodiments, reference is made to Figure 1 As shown, the rated displacement of the first main pump 3 in the test system is less than the rated displacement of the second main pump 4. Specifically, the rated displacement of the first main pump 3 is, but is not limited to, configured as 125 mL / r, and correspondingly, the rated displacement of the second main pump 4 is, but is not limited to, configured as 250 mL / r.

[0047] Furthermore, the oil passage diameter of the first main oil circuit reversing pressure regulating valve assembly 18 is smaller than that of the second main oil circuit reversing pressure regulating valve assembly 19. Specifically, the first main oil circuit reversing pressure regulating valve assembly 18 includes, but is not limited to, being configured with a 16mm diameter oil passage to suit hydraulic cylinders with small to medium flow rates and pressure specifications; while the second main oil circuit reversing pressure regulating valve assembly 19 includes, but is not limited to, being configured with a 32mm diameter oil passage to allow for a larger flow rate compared to the first main oil circuit reversing pressure regulating valve assembly 18, thereby meeting the testing requirements of hydraulic cylinders with higher power and / or larger specifications.

[0048] In some illustrative embodiments, reference is made to Figure 1 As shown, the output oil circuit of the first main pump 3 is connected to the first main oil circuit reversing pressure regulating valve group 18, and the output oil circuit of the second main pump 4 is connected to the second main oil circuit reversing pressure regulating valve group 19. A closable confluence valve 76 is provided between the two output oil circuits. The confluence valve 76 may include, but is not limited to, a ball valve. Specifically, the PA1 port of the first main oil circuit flow metering safety valve group 12 is connected to the P port of the first main oil circuit reversing pressure regulating valve group 18; the PB1 port of the first main oil circuit flow metering safety valve group 12 is connected to the PC1 port of the first main oil circuit reversing pressure regulating valve group 18 via the confluence valve 76, and then connected to the P port of the second main oil circuit reversing pressure regulating valve group 19, thereby providing a larger test flow rate for the hydraulic cylinder under test.

[0049] Based on this, for different specifications of the tested hydraulic cylinder, if the demand flow of the tested hydraulic cylinder is low, only the small displacement first main pump 3 can be started and the confluence valve 76 can be closed; if the demand flow is medium, only the large displacement second main pump 4 can be started; if the demand flow is very high, both the first main pump 3 and the second main pump 4 can be started at the same time and the confluence valve 76 can be opened so that the oil can be supplied after confluence, so as to achieve adaptive oil supply capacity and energy saving.

[0050] In this implementation, the test system constructs two independent test channels with stepped performance parameters by setting up a first main pump 3 and a second main pump 4 with different rated displacements, and a first main oil circuit reversing pressure regulating valve group 18 and a second main oil circuit reversing pressure regulating valve group 19 with different oil circuit diameters.

[0051] Building upon this foundation, for small-sized hydraulic cylinders under test, a channel consisting of a small-displacement pump and a small-diameter valve assembly can be used. Its output flow rate is more closely matched to the testing requirements, reducing overflow losses and facilitating fine-tuning of flow rate and pressure stability. For large-sized hydraulic cylinders under test, a channel consisting of a large-displacement pump and a large-diameter valve assembly can be used. Its ample flow rate significantly shortens filling and running time, improving testing efficiency. Furthermore, the merging valve 76 between the two independent testing channels can combine the outputs of the first main pump 3 and the second main pump 4 when needed, providing a larger peak flow rate to meet the testing requirements of larger-sized hydraulic cylinders. In this way, the testing system can select an appropriate operating mode based on the specifications of the tested object, thereby solving the problems of limited testing capabilities for only a single specification of hydraulic cylinder in related technologies, as well as the high energy consumption, difficulty in precision control, or low efficiency issues when adapting to hydraulic cylinders of different sizes.

[0052] In some illustrative embodiments, reference is made to Figure 1 As shown, the test system also includes a first filter 9, a second filter 10, a third filter 11, and a fourth filter 78. Specifically, the first filter 9 is located at the outlet of the first control pump 2; the second filter 10 is located at the outlet of the first main pump 3; the third filter 11 is located at the outlet of the second main pump 4; and the fourth filter 78 is located at the outlet of the first circulating pump 5. Furthermore, the test system is also configured with a first oil cooler 79, which, together with the fourth filter 78 and the first circulating pump 5, forms an independent circulating cooling circuit. This circuit draws oil from the oil tank 1, filters and cools it, and then returns the oil to the oil tank 1, thereby exchanging heat with the main working circuit of the test system at the oil tank to maintain a stable system oil temperature.

[0053] In some illustrative embodiments, reference is made to Figure 1 As shown, the test system also includes a first return oil multi-port block 77, which serves to collect low-pressure oil from various circuits within the test system. Specifically, the oil return port T and drain port L from the first main oil circuit reversing pressure regulating valve group 18, the oil return port T and drain port L from the second main oil circuit reversing pressure regulating valve group 19, the drain port L from the first control oil pressure regulating safety valve group 13, and the oil outlet A from the first bypass electro-proportional relief valve 15 and the second bypass electro-proportional relief valve 17 are respectively connected to the corresponding inlets T1 to T5 on the first return oil multi-port block 77. All the return and drain oil from different branches entering the first return oil multi-port block 77 are collected in its internal cavity and then transported back to the oil tank 1 through a unified pipeline via its total outlet T6. This integrated design effectively simplifies the external pipeline layout of the system, reduces the number of pipeline joints, and improves the reliability and maintenance convenience of the test system.

[0054] Figure 2 yes Figure 1The diagram shows the hydraulic schematic of the main oil circuit flow metering safety valve assembly in the hydraulic cylinder testing system.

[0055] According to embodiments of this disclosure, referring to Figure 1 and Figure 2 As shown, the third outlet PB1 of the first main oil circuit flow metering safety valve group 12 is connected to the inlet of the second main oil circuit reversing pressure regulating valve group 19 to provide a pressure oil source for the second main oil circuit reversing pressure regulating valve group 19. The fourth outlet PB2 of the first main oil circuit flow metering safety valve group 12 is connected to the inlet of the second bypass electro-proportional relief valve 17 through the second ball valve 16. The second bypass electro-proportional relief valve 17 is configured to work in conjunction with the second main oil circuit reversing pressure regulating valve group 19 when the second ball valve 16 is open to regulate the system pressure of the second test branch.

[0056] According to embodiments of this disclosure, referring to Figure 1 and Figure 2 As shown, the inlet of the first main oil circuit flow metering safety valve group 12 is connected to the output oil circuit of the first main pump 3 and / or the second main pump 4, and the outlet of the first main oil circuit flow metering safety valve group 12 is connected to the inlet of the first main oil circuit reversing pressure regulating valve group 18 and / or the second main oil circuit reversing pressure regulating valve group 19. The first main oil circuit flow metering safety valve group 12 includes a valve block 121, a first safety protection unit and a second safety protection unit in parallel. The first safety protection unit includes a first two-way loading cartridge valve 1212, a first pilot loading valve 1213 for setting the pilot pressure of the first two-way loading cartridge valve 1212, and a first pressure shut-off valve 1214 connected in parallel with the first pilot loading valve 1213. The first safety protection unit is used to provide a pressure oil source for the first main oil circuit reversing pressure regulating valve group 18 and set the maximum safety pressure. The second safety protection unit includes a second two-way loading cartridge valve, a second pilot loading valve 1217 for setting a pilot pressure for the second two-way loading cartridge valve, and a second pressure shut-off valve 1218 connected in parallel with the second pilot loading valve 1217. The second safety protection unit is used to provide a pressure oil source for the second main oil circuit reversing pressure regulating valve group 19 and set the maximum safety pressure. The first main oil circuit flow metering safety valve group 12 also integrates a first flow meter 1219 and a first pressure sensor 1221, configured to monitor the flow rate and pressure of the oil flowing to the first main oil circuit reversing pressure regulating valve group 18; and a second flow meter 1220 and a second pressure sensor 1222, configured to monitor the flow rate and pressure of the oil flowing to the second main oil circuit reversing pressure regulating valve group 19.

[0057] According to embodiments of this disclosure, referring to Figure 1 and Figure 2As shown, the first main oil circuit flow metering safety valve group 12 also includes a first internally controlled cartridge valve 1223 and a second internally controlled cartridge valve 1224. The control chambers of the first internally controlled cartridge valve 1223 and the second internally controlled cartridge valve 1224 are connected to a control oil circuit and the corresponding main oil circuit. The first internally controlled cartridge valve 1223 and the second internally controlled cartridge valve 1224 are configured to use the higher pressure between the control oil pressure and the main oil circuit pressure as the effective control pressure.

[0058] In some illustrative embodiments, reference is made to Figure 1 and Figure 2 As shown, the first main oil circuit flow metering safety valve group 12 is configured to set the safety pressure of the test system and monitor the safety pressure in real time. Specifically, the first main oil circuit flow metering safety valve group 12 includes a valve block 121 and two parallel safety protection units. The first safety protection unit includes a first two-way loading cartridge valve 1212, a first pilot loading valve 1213 for setting the pilot pressure, and a first pressure shut-off valve 1214. The second safety protection unit includes a second two-way loading cartridge valve 1216, a second pilot loading valve 1217, and a second pressure shut-off valve 1218. The valve group also integrates a first flow meter 1219, a second flow meter 1220, a first pressure sensor 1221, and a second pressure sensor 1222, used to monitor the flow rate and pressure of the oil flowing to the two main oil circuits and to collect the data for display on a host computer.

[0059] Based on this, the oil from the first main pump 3 and the second main pump 4 enters two independent safety protection units. Specifically, the first pressure shut-off valve 1214 is used to control the pressure application and depressurization of the first two-way loading cartridge valve 1212; the second pressure shut-off valve 1218 is correspondingly used to control the pressure application and depressurization of the second two-way loading cartridge valve 1216. Furthermore, the first internally controlled cartridge valve 1223 and the second internally controlled cartridge valve 1224 normally use the stable control oil pressure from the first control oil pressure regulating safety valve group 13 as their reference control pressure. However, when the main oil circuit pressure is higher than this control oil pressure, the main oil circuit pressure is preferentially used as its effective control pressure (i.e., the higher pressure is used as the effective control pressure). This ensures the stability and reliability of the valve group control under test conditions of system pressure changes.

[0060] According to embodiments of this disclosure, referring to Figure 1As shown, a first bypass electro-proportional relief valve 15 is provided on the bypass of the first main oil circuit reversing pressure regulating valve group 18, and a second bypass electro-proportional relief valve 17 is provided on the bypass of the second main oil circuit reversing pressure regulating valve group 19. The first bypass electro-proportional relief valve 15 and the second bypass electro-proportional relief valve 17 are configured to, during the start-up pressure test, cooperate with the first electro-proportional pilot loading valve 1821 and the second electro-proportional pilot loading valve 1920 in the first main oil circuit reversing pressure regulating valve group 18 or the second main oil circuit reversing pressure regulating valve group 19, respectively, to perform pressure compensation regulation.

[0061] In some illustrative embodiments, reference is made to Figure 1 As shown, the oil inlet of the first bypass proportional relief valve 15 is connected to the PA2 port of the first main oil circuit flow metering safety valve group 12 through the first ball valve 14. The oil inlet of the second bypass proportional relief valve 17 is connected to the PB2 port of the first main oil circuit flow metering safety valve group 12 through the second ball valve 16.

[0062] In some illustrative embodiments, reference is made to Figure 1 As shown, the first pilot loading valve 1821 is integrated into the first main oil circuit reversing pressure regulating valve group 18. Its inlet port P is connected to the main inlet port P of the valve group, receiving the main oil source from the first main pump 3. Its return port A is connected to the drain port L of the valve group. Its output port X is connected to the control chamber of the main pressure regulating cartridge valve in the valve group through an internal oil passage. The second electro-proportional pilot loading valve 1920 is arranged symmetrically and integrated into the second main oil circuit reversing pressure regulating valve group 19. Its inlet port is connected to the main inlet port of the valve group, and the oil source comes from the second main pump 4 or from the confluence of the second main pump 4 and the first main pump 3 when the confluence valve 76 is open.

[0063] When the test system performs a start-up pressure test, the pressure needs to be finely and continuously adjusted at extremely low flow rates to accurately capture the critical point at which the tested hydraulic cylinder begins to move. However, since the first pilot loading valve 1821 and the second electro-proportional pilot loading valve 1920 need to cover a wide operating flow range, the linear relationship and resolution between their control signals and valve opening will decrease under low flow conditions, which can easily lead to nonlinearity or lag in pressure regulation, making it difficult to achieve precise micro-pressure control.

[0064] Therefore, in this embodiment, a first bypass electro-proportional relief valve 15 and a second bypass electro-proportional relief valve 17 are respectively added to the bypasses of the first main oil circuit reversing pressure regulating valve group 18 and the second main oil circuit reversing pressure regulating valve group 19. These two bypass relief valves are specifically designed for low-flow, high-precision pressure regulation conditions, featuring a smaller valve core stroke and higher control resolution. Thus, during the start-up pressure test, the test system can switch the first main pump 3 and / or the second main pump 4 to a small-displacement mode, and by opening the corresponding first ball valve 14 or second ball valve 16, allow the oil to flow through the corresponding bypass branch. At this time, the precise regulation of the system pressure is mainly undertaken by the bypass valve, which can stably, continuously, and accurately control the pressure under small flow rates based on high-resolution electrical signals.

[0065] Figure 3 yes Figure 1 The diagram shows the hydraulic schematic of the control oil pressure regulating safety valve assembly in the hydraulic cylinder test system.

[0066] According to embodiments of this disclosure, referring to Figure 1 and Figure 3 As shown, the test system also includes a first control pump 2, a first control oil pressure regulating safety valve assembly 13, and an accumulator 22. The input oil circuit of the first control pump 2 is connected to the oil tank 1 to provide the control oil source. The first control oil pressure regulating safety valve assembly 13 is connected to the output oil circuit of the first control pump 2 to regulate and provide a stable control oil supply. The accumulator 22 is connected to the control oil circuit provided by the first control oil pressure regulating safety valve assembly 13.

[0067] In some illustrative embodiments, reference is made to Figure 1 and Figure 3 As shown, the first control oil pressure regulating safety valve assembly 13 includes a first control oil pressure regulating safety valve block 131, a first control oil safety valve 1311, a first control oil pressure reducing valve 1312, a first control oil pressure sensor 1313, and a second control oil pressure sensor 1314. Specifically, the valve block 131 is provided with a first oil inlet Px, a first oil outlet Kj, a first oil outlet Pc, a first oil outlet Px1, a second oil outlet Px2, and a first drain port L. The corresponding oil circuit connections include: the oil inlet Px is connected through an internal oil passage in the valve block to the oil inlet of the first control oil safety valve 1311, the oil inlet of the first control oil pressure reducing valve 1312, and the pressure measuring point of the first control oil pressure sensor 1313. The oil outlet of the first control oil pressure reducing valve 1312 is connected through an internal oil passage to the pressure measuring point of the second control oil pressure sensor 1314, and the oil outlets Kj, Pc, Px1, and Px2. The drain port Y of the first control oil pressure reducing valve 1312 and the return port A of the first control oil safety valve 1311 are both connected to the drain port L of the valve block.

[0068] In this implementation, pressurized oil from the first control pump 2 enters the first control oil pressure regulating safety valve group 13 through port Px. The first control oil safety valve 1311 acts as a safety barrier, used to set and limit the maximum safe pressure of the control oil circuit. The first control oil pressure reducing valve 1312 in the first control oil pressure regulating safety valve group 13 includes, but is not limited to, being configured as an electro-proportional control type, which can receive remote electrical signals from the host computer to achieve stepless and precise setting and regulation of the output control oil pressure. The control oil, after being stabilized by the first control oil pressure reducing valve 1312, is output from port Kj to energy storage and execution units such as the accumulator 22; output from port Pc to the first main oil circuit flow metering safety valve group 12 to provide control oil; and output from ports Px1 and Px2 to the first main oil circuit reversing pressure regulating valve group 18 and the second main oil circuit reversing pressure regulating valve group 19, respectively, to provide pilot control oil. The first control oil pressure sensor 1313 and the second control oil pressure sensor 1314 monitor the input and output pressures of the valve group in real time and feed the signals back to the host computer, forming the basis of closed-loop control, thereby ensuring that the system control oil pressure is stable, adjustable and safe.

[0069] In some illustrative embodiments, reference is made to Figure 1 and Figure 3 As shown, the accumulator 22 is directly connected to the system control oil circuit established and regulated by the first control oil pressure regulating safety valve group 13. Specifically, its inlet is connected to the outlet Kj port of the valve group through a pipeline. To realize its energy recovery and auxiliary return function, multiple oil circuits branch off from this control oil circuit node, and are connected to the dedicated control oil ports (Pka, Pkb) on the first hydraulic cylinder A port integrated multi-port block 25, the first hydraulic cylinder B port integrated multi-port block 46, the second hydraulic cylinder A port integrated multi-port block 49, and the second hydraulic cylinder B port integrated multi-port block 70 through independent control valves such as the fifth ball valve 27, the fifteenth ball valve 73, the sixteenth ball valve 74, and the seventeenth ball valve 75. The oil passages inside these integrated blocks are ultimately connected to the pilot control chamber X port of the first main oil circuit reversing pressure regulating valve group 18 and the second main oil circuit reversing pressure regulating valve group 19. In addition, a first ball valve 20 and a second ball valve 21 are connected in series on the main oil inlet line of the accumulator 22 as its pressure control valves for charging and discharging, and a third ball valve 23 is connected in parallel as a safety pressure relief valve for the entire control oil circuit.

[0070] Since the accumulator 22 is directly connected in parallel to the control oil circuit, when the system experiences pressure fluctuations due to commutation or sudden load changes, the accumulator 22 can utilize the compressibility of its own gas to instantly absorb or replenish oil, thereby effectively filtering out pressure pulsation peaks. This is equivalent to forming a pressure-stabilized liquid chamber, directly protecting the connected precision pilot valves and downstream pipelines, and improving the stability and reliability of the test system operation.

[0071] In addition, based on the aforementioned accumulator 22, after the test is completed and the main pump stops running, the test system only needs to open the corresponding ball valves leading to the target test branch (such as the fifth ball valve 27 and the fifteenth ball valve 73 mentioned above). The pressure oil pre-stored in the accumulator 22 can then directly drive the pilot chamber of the corresponding reversing pressure regulating valve group (the first main oil circuit reversing pressure regulating valve group 18 or the second main oil circuit reversing pressure regulating valve group 19) through the established path to reverse its direction. This allows the return action of the tested hydraulic cylinder to be completed entirely by the energy released by the accumulator without relying on the main pump to restart the oil supply, thereby reducing the ineffective running time and start-stop frequency of the main pump and achieving a significant energy-saving effect.

[0072] Figure 4 yes Figure 1 The diagram shows the hydraulic principle of the first main oil circuit reversing pressure regulating valve group in the hydraulic cylinder test system. Figure 5 yes Figure 1 The diagram shows the hydraulic principle of the second main oil circuit reversing pressure regulating valve group in the hydraulic cylinder test system.

[0073] According to embodiments of this disclosure, referring to Figure 4 and Figure 5 As shown, the test system also includes at least two sets of hydraulic cylinder interface integration blocks. Each set of hydraulic cylinder interface integration blocks includes an A-port integration block and a B-port integration block. Each of the A-port integration block and the B-port integration block is provided with multiple quick-release interfaces.

[0074] According to embodiments of this disclosure, referring to Figure 4 and Figure 5 As shown, at least two sets of hydraulic cylinder interface integration blocks include a first test branch and a second test branch. Specifically, the first hydraulic cylinder A port integrates a multi-pass block 25 and the first hydraulic cylinder B port integrates a multi-pass block 46 to form the first test branch; the second hydraulic cylinder A port integrates a multi-pass block 49 and the second hydraulic cylinder B port integrates a multi-pass block 70 to form the second test branch. The first test branch and / or the second test branch are configured to be connected in parallel with the hydraulic cylinder under test via a quick-release interface.

[0075] According to embodiments of this disclosure, referring to Figure 1 , Figure 4 and Figure 5As shown, the first main hydraulic circuit reversing pressure regulating valve group 18 and / or the second main hydraulic circuit reversing pressure regulating valve group 19 are configured to have at least a first state, a second state, and a third state. In the first state, the P port of the first main hydraulic circuit reversing pressure regulating valve group 18 and / or the second main hydraulic circuit reversing pressure regulating valve group 19 is connected to the PA1 port, and the PB1 port is connected to the T port, so as to drive the piston rod of the hydraulic cylinder under test to extend; in the second state, the P port of the first main hydraulic circuit reversing pressure regulating valve group 18 and / or the second main hydraulic circuit reversing pressure regulating valve group 19 is connected to the PB1 port, and the PA1 port is connected to the T port, so as to drive the piston rod of the hydraulic cylinder under test to retract; in the third state, the P port, PA1 port, PB1 port, and T port of the first main hydraulic circuit reversing pressure regulating valve group 18 and / or the second main hydraulic circuit reversing pressure regulating valve group 19 are mutually disconnected, so that the hydraulic cylinder under test is held in a predetermined position.

[0076] According to embodiments of this disclosure, referring to Figure 1 , Figure 4 and Figure 5 As shown, the first main oil circuit reversing pressure regulating valve group 18 includes a second cartridge valve 1812, a third cartridge valve 1813, a fourth cartridge valve 1814, a fifth cartridge valve 1815, a first pilot on / off valve 1822, and a second pilot on / off valve 1823. In the first state, the first pilot on / off valve 1822 is de-energized, the third cartridge valve 1813 and the fifth cartridge valve 1815 are closed, the second pilot on / off valve 1823 is energized, and the second cartridge valve 1812 and the fourth cartridge valve 1814 are open. In the second state, the first pilot on / off valve 1822 is energized, the third cartridge valve 1813 and the fifth cartridge valve 1815 are open, the second pilot on / off valve 1823 is de-energized, and the second cartridge valve 1812 and the fourth cartridge valve 1814 are closed. In the third state, neither the first pilot shut-off valve 1822 nor the second pilot shut-off valve 1823 is energized, and the second cartridge valve 1812, the third cartridge valve 1813, the fourth cartridge valve 1814, and the fifth cartridge valve 1815 are closed.

[0077] According to embodiments of this disclosure, referring to Figure 1 , Figure 4 and Figure 5As shown, the second main oil circuit reversing pressure regulating valve group 19 includes a second cartridge valve 1912, a third cartridge valve 1913, a fourth cartridge valve 1914, a fifth cartridge valve 1915, a first pilot on / off valve 1921, and a second pilot on / off valve 1922. In the first state, the first pilot on / off valve 1921 is de-energized, the third cartridge valve 1913 and the fifth cartridge valve 1915 are closed, and the controller is also configured to energize the second pilot on / off valve 1922 and open the second cartridge valve 1912 and the fourth cartridge valve 1914. In the second state, the first pilot on / off valve 1921 is energized, the third cartridge valve 1913 and the fifth cartridge valve 1915 are open, the second pilot on / off valve 1922 is de-energized, the second cartridge valve 1912 and the fourth cartridge valve 1914 are closed, and the third cartridge valve 1913 and the fifth cartridge valve 1915 are open. In the third state, the first pilot shut-off valve 1921 and the second pilot shut-off valve 1922 are not energized, and the second cartridge valve 1912, the third cartridge valve 1913, the fourth cartridge valve 1914 and the fifth cartridge valve 1915 are all closed.

[0078] In some illustrative embodiments, reference is made to Figure 1 As shown, the testing system is also configured to be electrically and / or communicatively connected to a host computer. Specifically, the host computer integrates control software, which includes, but is not limited to, a dedicated automated test interface and logic for at least a portion of the test items, including trial run exhaust, start-up pressure test, withstand pressure test, internal leakage test, buffer test, and stroke inspection, to integrate discrete manual procedures into a coherent automated process. Furthermore, the testing system also includes a first test branch and a second test branch.

[0079] In the first test branch, the first hydraulic cylinder A-port integrated multi-pass block 25 is equipped with a first hydraulic cylinder A-port integrated block pressure sensor 26, which is used to directly measure the pressure at the rodless chamber A-port of the first measuring hydraulic cylinder 30, the second measuring hydraulic cylinder 36, and the third tested hydraulic cylinder 42 connected in parallel. Correspondingly, the first hydraulic cylinder B-port integrated multi-pass block 46 is equipped with a first hydraulic cylinder B-port integrated block pressure sensor 48, which is used to measure the pressure at the rod chamber B-port of the above three hydraulic cylinders in the same group. At the same time, in order to monitor the motion status, this first test branch is also equipped with a first hydraulic cylinder stroke detection sensor 29, a second hydraulic cylinder stroke detection sensor 35, and a third hydraulic cylinder stroke detection sensor 41, which are used to detect the position and stroke of the piston rod of the corresponding tested hydraulic cylinder in real time.

[0080] The second test branch employs a symmetrical arrangement similar to that of the first test branch. The second hydraulic cylinder A-port integrated multi-pass block 49 and the second hydraulic cylinder B-port integrated multi-pass block 70 are respectively equipped with a second hydraulic cylinder A-port integrated block pressure sensor 50 and a second hydraulic cylinder B-port integrated block pressure sensor 71, used to measure the pressure at ports A and B of the fourth measuring hydraulic cylinder 53, the fifth measuring hydraulic cylinder 59, and the sixth tested hydraulic cylinder 65. This second test branch also includes a fourth hydraulic cylinder stroke detection sensor 52, a fifth hydraulic cylinder stroke detection sensor 58, and a sixth hydraulic cylinder stroke detection sensor 64, used to measure the stroke of the corresponding hydraulic cylinders.

[0081] In this implementation, in the main oil circuit, a first pressure sensor 1221, a second pressure sensor 1222, a first flow meter 1219, and a second flow meter 1220 are installed on the first main oil circuit flow metering safety valve group 12 to monitor the pressure and flow of the oil source; in the control oil circuit, a first control oil pressure sensor 1313 and a second control oil pressure sensor 1314 are provided on the first control oil pressure regulating safety valve group 13; at the test execution end, each hydraulic cylinder interface integrated block (25, 46, 49, 70) is equipped with an integrated block pressure sensor (26, 48, 50, 71) to directly measure the pressure of the working chamber of the tested hydraulic cylinder; at the same time, multiple stroke detection sensors (29, 35, 41, 52, 58, 64) are configured to detect the position of the piston rod of each hydraulic cylinder in real time. Thus, by selecting a high-precision pressure sensor (with a measurement accuracy of ±0.05MPa) and combining it with high-resolution flow and displacement sensing elements, the data acquisition unit can synchronously and continuously monitor and record key parameters throughout the entire testing process with high precision.

[0082] Furthermore, operators can remotely set various test parameters, select or combine test modes, and initiate preset automated test sequences through the software interface configured on the host computer. The host computer automatically generates control commands based on the established program logic, precisely adjusting the system pressure by controlling the first electro-proportional pilot loading valve 1821 or the second electro-proportional pilot loading valve 1920, and driving the hydraulic cylinder to move by sending timing signals to the first pilot on / off valve (1822, 1823) or the second pilot on / off valve (1921, 1922), thereby achieving automatic progression and mode switching of the test process. Taking test run exhaust as an example: after selecting the item on the host computer interface, the operator can preset the number of reversing cycles (e.g., 5-10 times). After startup, the host computer automatically controls the relevant valve groups, causing the piston rod of the tested hydraulic cylinder to perform a full-stroke reciprocating motion under low pressure, and automatically counts the number of cycles. After reaching the preset value, the system automatically ends the exhaust and seamlessly enters the next test item (e.g., starting pressure test). Throughout the entire testing process, from parameter setting, action execution, data collection to result judgment and storage, no manual intervention is required for reversing, voltage adjustment, or recording operations, which greatly improves testing efficiency, consistency, and the objectivity and reliability of the data.

[0083] It should be noted that the software configured to implement various functions of the above-mentioned test system, the software interface, and the control flow and / or data flow used to control the test system to perform corresponding actions are not the focus of protection of this disclosure. Any software that can be used in the field for the test system and the host computer including the software can be selected and applied, and will not be elaborated further.

[0084] Based on the disclosed embodiments, continue to refer to Figure 4 and Figure 5As shown, the first main oil circuit reversing pressure regulating valve group 18 also includes a first cartridge valve 1811 and a sixth cartridge valve 1816. The first cartridge valve 1811 is connected between the first oil outlet PA1 and the first oil return port T of the valve block 181, and the sixth cartridge valve 1816 is connected between the second oil outlet PB1 and the first oil return port T of the valve block 181. When the first main oil circuit reversing pressure regulating valve group 18 is in the third state, both the first cartridge valve 1811 and the sixth cartridge valve 1816 are configured to be closed to disconnect the connection between the first oil outlet PA1 and the second oil outlet PB1 and the oil return circuit. The test system also includes multiple sets of measuring cylinders (33, 39, 45), each set of measuring cylinders is connected to the oil return branch of the first hydraulic cylinder A port integrated multi-port block 25 or the first hydraulic cylinder B port integrated multi-port block 46 through an independent leakage measuring valve (which may be the sixth ball valve 32, the seventh ball valve 38, or the eighth ball valve 44 described below). And / or, the second main oil circuit reversing pressure regulating valve group 19 also includes a first cartridge valve 1911 and a sixth cartridge valve 1916. The first cartridge valve 1911 is connected between port A PA2 and return port T of the valve block, and the sixth cartridge valve 1916 is connected between port B PB2 and return port T of the valve block. When the second main oil circuit reversing pressure regulating valve group 19 is in the third state, both the first cartridge valve 1911 and the sixth cartridge valve 1916 are controlled to be closed to disconnect port A PA2 and port B PB2 from the return oil circuit. The test system also includes multiple sets of measuring cylinders (56, 62, 68), each set of measuring cylinders being connected to the return oil branch of the second hydraulic cylinder A port integrated multi-port block 49 or the second hydraulic cylinder B port integrated multi-port block 70 through an independent leakage measuring valve (55, 61, 67). When conducting an internal leakage test, the corresponding leakage measurement valve is opened, allowing the oil leaking from the piston of the hydraulic cylinder under test to be directly guided to the corresponding measuring cylinder for volume measurement.

[0085] Based on the embodiments of this disclosure, continue to refer to Figure 4 and Figure 5 As shown, when the first main oil circuit reversing pressure regulating valve group 18 is in the third state, the second cartridge valve 1812, the third cartridge valve 1813, the fourth cartridge valve 1814, the fifth cartridge valve 1815, the first cartridge valve 1811, and the sixth cartridge valve 1816 are all closed, so as to achieve complete isolation of all working oil ports PA1, PB1 from the pressure source P port, the return oil port T port, and the pilot control oil circuit X port within the valve group. And / or, when the second main oil circuit reversing pressure regulating valve group 19 is in the third state, the second cartridge valve 1912, the third cartridge valve 1913, the fourth cartridge valve 1914, the fifth cartridge valve 1915, the first cartridge valve 1911, and the sixth cartridge valve 1916 are all closed, so as to achieve complete isolation of all working oil ports PA2, PB2 from the pressure source P port, the return oil port T port, and the pilot control oil circuit within the valve group.

[0086] Based on the embodiments of this disclosure, continue to refer to Figure 4 and Figure 5 As shown, the first hydraulic cylinder A-port integrated multi-port block 25 and the first hydraulic cylinder B-port integrated multi-port block 46 each have three independent leakage measurement branches corresponding to their respective quick-release interfaces. Each leakage measurement branch includes a leakage measuring valve and a measuring cylinder arranged in series. The leakage measurement branch is connected between the corresponding quick-release interface and the system return oil circuit, and the leakage measuring valve is located upstream of the measuring cylinder. And / or, the second hydraulic cylinder A-port integrated multi-port block 49 and the second hydraulic cylinder B-port integrated multi-port block 70 each have three independent leakage measurement branches corresponding to their respective three quick-release interfaces (having ports A1, A2, and A3, and ports B1, B2, and B3). That is to say, the testing device can simultaneously test six hydraulic cylinders under test. Each leakage measurement branch includes a leakage measuring valve and a measuring cylinder arranged in series. The leakage measurement branch is connected between the corresponding quick-release interface and the system return oil circuit, and the leakage measuring valve is located upstream of the measuring cylinder.

[0087] In some illustrative embodiments, reference is made to Figure 4 As shown, the first main oil circuit reversing pressure regulating valve group 18 includes a valve block 181; eight two-way cartridge valves, namely the first cartridge valve 1811, the second cartridge valve 1812, the third cartridge valve 1813, the fourth cartridge valve 1814, the fifth cartridge valve 1815, the sixth cartridge valve 1816, the seventh cartridge valve 1817 and the eighth cartridge valve 1818; a first main oil circuit 16 through-hole electro-proportional loading module 1819, which includes a first mechanical pilot loading valve 1820 and a first electro-proportional pilot loading valve 1821; and four pilot on-off valves, namely the first pilot on-off valve 1822, the second pilot on-off valve 1823, the third pilot on-off valve 1824 and the fourth pilot on-off valve 1825.

[0088] Furthermore, the valve block 181 is provided with a first oil inlet P, a first oil outlet PA1, a second oil outlet PB1, a third oil outlet PC1, a first control oil port X, a first drain oil port L, and a first return oil port T. Specifically, the internal oil circuit connection relationship of the valve block 181 includes: the first oil inlet P is connected through an internal oil passage to the P port of the second cartridge valve 1812, the P port of the fifth cartridge valve 1815, the P port of the seventh cartridge valve 1817, the P port of the eighth cartridge valve 1818, the first control oil port X, and the P ports of the first electro-proportional pilot-loaded valve 1821 and the first mechanical pilot-loaded valve 1820. The P port of the third cartridge valve 1813 is connected to the A port of the eighth cartridge valve 1818, and its A port is connected to the A port of the second cartridge valve 1812 and the A port of the first cartridge valve 1811.

[0089] Furthermore, the P port of the first cartridge valve 1811 is connected to the P port of the fourth pilot shut-off valve 1825 and the first oil outlet PA1; the T port of the fourth pilot shut-off valve 1825 is connected to the drain port L, and its A port is connected to the X control port of the cartridge valve 1811. The A port of the eighth cartridge valve 1818 is also connected to the P port of the fourth cartridge valve 1814; the A port of the fourth cartridge valve 1814 is connected to the A ports of the fifth cartridge valve 1815 and the sixth cartridge valve 1816. The P port of the sixth cartridge valve 1816 is connected to the P port of the third pilot shut-off valve 1824 and the second oil outlet PB1; the T port of the pilot shut-off valve 1824 is connected to the drain port L, and its A port is connected to the X control port of the cartridge valve 1816. The first control port X is connected to the P port of the first pilot on / off valve 1822 and the second pilot on / off valve 1823; the T ports of both pilot on / off valves are connected to the drain port L; by controlling the on / off state of these two valves, pilot control oil can be guided to the X control port of cartridge valves 1812, 1813, 1814, and 1815, thereby realizing the reversal of the main oil circuit. The A and X ports of the seventh cartridge valve 1817 are connected to the third outlet port PC1 for oil circuit merging. The return oil of all pilot loading valves and pilot on / off valves is connected to the drain port L.

[0090] Based on this, the working principle of the first main oil circuit reversing pressure regulating valve group 18 is as follows: the main pressure oil from the first main oil circuit flow metering safety valve group 12PA1 port enters through port P. The system pressure is remotely electro-proportionally regulated by the first electro-proportional pilot loading valve 1821 or the first mechanical pilot loading valve 1820 through the control of the eighth cartridge valve 1818. The direction of hydraulic cylinder movement is achieved by the first pilot on / off valve 1822 and the second pilot on / off valve 1823 controlling the opening and closing combinations of the second cartridge valve 1812, the third cartridge valve 1813, the fourth cartridge valve 1814, and the fifth cartridge valve 1815. Specifically, when the hydraulic cylinder needs to extend, the relevant pilot valves are controlled to open the second cartridge valve 1812 and the fourth cartridge valve 1814, and close the third cartridge valve 1813 and the fifth cartridge valve 1815. Pressure oil enters the rodless chamber of the cylinder from port PA1, and the oil in the rod chamber returns from port PB1 via the return oil circuit. When retracted, the valve state is the opposite of the above. When pressure holding or stopping is required (i.e., the third state), the second cartridge valve 1812, the third cartridge valve 1813, the fourth cartridge valve 1814, and the fifth cartridge valve 1815 are closed. At this time, the first cartridge valve 1811 and the sixth cartridge valve 1816 are also closed under the control of their respective pilot valves, thereby completely physically isolating the working ports PA1 and PB1 from the pressure source (P port), the return port (T port), and the pilot control oil circuit. In this way, by utilizing the high sealing performance of the above cartridge valves, the working chamber of the tested hydraulic cylinder can be locked into a closed cavity, achieving reliable pressure holding and position locking.

[0091] The second main oil circuit reversing pressure regulating valve group 19 is similar in structure and principle to the first main oil circuit reversing pressure regulating valve group 18 described above, but with a larger oil circuit diameter to accommodate larger flow rate testing requirements. Its specific components include: a first main oil circuit 32-diameter reversing pressure regulating valve block 191; seven two-way cartridge valves, namely, first cartridge valve 1911, second cartridge valve 1912, third cartridge valve 1913, fourth cartridge valve 1914, fifth cartridge valve 1915, sixth cartridge valve 1916, and seventh cartridge valve 1917; a first main oil circuit 32-diameter electro-proportional loading module 1918, including a first electro-proportional pilot loading valve 1919 and a second electro-proportional pilot loading valve 1920; and four pilot on / off valves, namely, a first pilot on / off valve 1921, a second pilot on / off valve 1922, a third pilot on / off valve 1923, and a fourth pilot on / off valve 1924.

[0092] Its internal oil circuit connection logic is similar to that of valve group 18. That is, the oil inlet P of the second main oil circuit reversing pressure regulating valve group 19 is connected to the P port and control oil port X of the second cartridge valve 1912, the fifth cartridge valve 1915, and the seventh cartridge valve 1917, as well as the P port of the second electro-proportional pilot loading valve 1920 and the first electro-proportional pilot loading valve 1919. The P port of the third cartridge valve 1913 is connected to the A port of the seventh cartridge valve 1917. The main pressure is regulated by the second electro-proportional pilot loading valve 1920 through controlling the seventh cartridge valve 1917. The reversing function is achieved by the first pilot on / off valve 1921 and the second pilot on / off valve 1922 controlling the second cartridge valve 1912, the third cartridge valve 1913, the fourth cartridge valve 1914, and the fifth cartridge valve 1915. When in the third state of pressure holding, the first cartridge valve 1911 and the sixth cartridge valve 1916 are also closed in a controlled manner to cut off the connection between the working oil ports PA2 and PB2 and the return oil circuit.

[0093] Furthermore, the first main oil circuit reversing pressure regulating valve group 18 or the second main oil circuit reversing pressure regulating valve group 19 enters its predefined third state (i.e., pressure holding state). In this state, all the main reversing cartridge valves inside the valve group, such as the second, third, fourth, and fifth cartridge valves, as well as the first and sixth cartridge valves used to isolate the return oil circuit, are closed, thereby achieving complete isolation between the working oil port (PA1 / PB1 or PA2 / PB2) and the pressure source P port, the system return oil circuit T port, and the pilot control oil circuit inside the valve group.

[0094] Subsequently, the system controls the closure of the corresponding shut-off valves connecting the reversing pressure regulating valve assembly and the hydraulic cylinder interface block. Specifically, for the first test branch, the fourth ball valve 24 and the ninth ball valve 47 are closed; for the second test branch, the thirteenth ball valve 69 and the fourteenth ball valve 72 are closed. These shut-off valves are located immediately adjacent to the hydraulic cylinder interface.

[0095] Through the above two steps, two continuous isolation barriers are established between the test chamber of the hydraulic cylinder under test and the reversing pressure regulating valve assembly supplying it with oil: the first barrier is provided by the reversing pressure regulating valve assembly itself in the third state; the second barrier is provided by the closed physical shut-off valve. This makes the test chamber of the hydraulic cylinder under test ultimately form a closed pressure-holding chamber that is only indirectly connected to the pump source system through the corresponding electro-proportional pilot loading valve, the first electro-proportional pilot loading valve 1821 or the second electro-proportional pilot loading valve 1920, and physically isolated from the main oil circuit and return oil circuit of the valve assembly. This eliminates the interference factor of pressure drop in the test chamber caused by the unavoidable minor leakage inside the reversing pressure regulating valve assembly. The maintenance and fine adjustment of pressure depend entirely on the precise control of the electro-proportional pilot loading valve and the compensation capability of the pump source, thereby ensuring the long-term stability of the pressure value and the extremely high accuracy of the measurement results during the pressure holding test.

[0096] Furthermore, based on the above implementation method, the internal leakage test function of the test system is specifically implemented as follows: The first hydraulic cylinder A port integrated multi-pass block 25 and the first hydraulic cylinder B port integrated multi-pass block 46 each have an independent leakage measurement branch corresponding to their quick-release interfaces. Each branch consists of a leakage measurement valve such as the sixth ball valve 32, the seventh ball valve 38, and the eighth ball valve 44, and a measuring cylinder such as the first measuring cylinder 33, the second measuring cylinder 39, and the third measuring cylinder 45 connected in series, and is connected between the corresponding quick-release interface and the system return oil circuit. The second test branch, the second hydraulic cylinder A port integrated multi-pass block 49, the second hydraulic cylinder B port integrated multi-pass block 70, and their leakage measurement branches, including leakage measurement valves (55, 61, 67) and measuring cylinders (56, 62, 68), have the same structure. When conducting an internal leakage test, after pressurizing one chamber of the hydraulic cylinder under test and using the other chamber as a leakage collection chamber in the corresponding reversing valve group, the leakage measurement valve on the return oil branch of the corresponding leakage collection chamber is opened, so that the oil leaking from the piston seal is directly introduced into the corresponding measuring cylinder for accurate volume measurement.

[0097] In view of the aforementioned hydraulic cylinder testing system, during the buffer test, the operator can pre-adjust the buffer adjustment device of the working chamber of the hydraulic cylinder under test to the fully open state according to the test procedure. Subsequently, the first electro-proportional pilot loading valve 1821 or the second electro-proportional pilot loading valve 1920 is remotely controlled via a host computer to precisely adjust the system test pressure to 50% of the nominal pressure of the hydraulic cylinder in an electro-proportional manner. Under this pressure setting, the hydraulic cylinder is driven to operate at the maximum design-permitted speed. When the piston reaches the buffer stroke section and the buffer valve gradually closes, the system monitors the pressure and speed change curves in real time through integrated pressure sensors and flow meters, thereby achieving dynamic detection and evaluation of the buffering effect.

[0098] For stroke verification, the testing system provides two compatible solutions. First, for hydraulic cylinders with built-in stroke sensors, their signal output terminals can be directly connected to the host computer's signal acquisition system. In this case, the first hydraulic cylinder stroke detection sensor 29, the second hydraulic cylinder stroke detection sensor 35, the third hydraulic cylinder stroke detection sensor 41, the fourth hydraulic cylinder stroke detection sensor 52, the fifth hydraulic cylinder stroke detection sensor 58, and the sixth hydraulic cylinder stroke detection sensor 64 installed at each test station can serve as backups or calibration benchmarks. Second, if the hydraulic cylinder under test is not equipped with a stroke sensor, the control system can be used to move the hydraulic cylinder piston or plunger to its extreme positions at both ends of the stroke, and then an external measuring instrument can be used to mechanically measure the stroke length.

[0099] The entire testing system is designed with high efficiency and intelligence in mind. All connections between the tested hydraulic cylinders and the test bench utilize quick-release interfaces (28, 31, 34, 37, 40, 43, 51, 54, 57, 60, 63, 66) and quick-connect tubing, greatly simplifying the assembly and disassembly process and shortening test preparation time. For core test items such as trial operation, starting pressure characteristics, pressure resistance, durability, and buffer tests, the host computer control software features a dedicated automated testing interface, integrating parameter preset, process control, and data recording functions. This allows for one-click, programmed, and continuous execution of complex multi-item tests.

[0100] Furthermore, the accumulator 22 added to the control oil circuit has dual beneficial effects. On the one hand, when the system experiences pressure fluctuations due to valve reversal or sudden load changes, the accumulator 22 can quickly absorb or release oil, effectively suppressing pressure peaks and valleys, smoothing hydraulic shocks, thereby protecting pipelines and valves, and improving the stability and reliability of system operation. On the other hand, after a single test cycle, there is no need to restart the main pump group; the pressure oil stored in the accumulator 22 can be directly used to drive the corresponding directional valve pilot chamber, providing power for the piston rod retraction of the tested hydraulic cylinder, thus realizing energy recovery and utilization. This not only reduces the number of ineffective start-stop cycles and idling energy consumption of the main pump, achieving the goal of energy saving and consumption reduction, but also ensures the speed and reliability of the actuator return operation.

[0101] It should also be noted that the directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," and "right," are only for reference to the directions in the accompanying drawings and are not intended to limit the scope of protection of this disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or constructions will be omitted where they may cause confusion in understanding this disclosure.

[0102] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A testing system for hydraulic cylinders, characterized in that, include: Oil tank (1) stores hydraulic oil; The first main pump (3) has an input oil circuit that is connected to the oil tank (1); The first main oil circuit reversing pressure regulating valve group (18) is connected to the output oil circuit of the first main pump (3); The second main pump (4) has an input oil circuit that is connected to the oil tank (1); The second main oil circuit reversing pressure regulating valve group (19) is connected to the output oil circuit of the second main pump (4), and a merging valve (76) is provided between the output oil circuit of the first main pump (3) and the output oil circuit of the second main pump (4). The rated displacement of the first main pump (3) is configured to be less than the rated displacement of the second main pump (4), and the oil passage diameter of the first main oil passage reversing pressure regulating valve group (18) is less than the oil passage diameter of the second main oil passage reversing pressure regulating valve group (19) to connect at least two hydraulic cylinders of different specifications.

2. The testing system according to claim 1, characterized in that, Also includes: At least two sets of hydraulic cylinder interface integration blocks, each set of hydraulic cylinder interface integration blocks includes an A-port integration block and a B-port integration block, and each of the A-port integration block and the B-port integration block is provided with multiple quick-release interfaces.

3. The testing system according to claim 2, characterized in that, At least two sets of hydraulic cylinder interface integration blocks include: The first hydraulic cylinder A port integrates a multi-pass block (25) and the first hydraulic cylinder B port integrates a multi-pass block (46) to form the first test branch; and The second hydraulic cylinder A port integrates a multi-pass block (49) and the second hydraulic cylinder B port integrates a multi-pass block (70) to form a second test branch; The first test branch and / or the second test branch are configured to connect the hydraulic cylinders under test in parallel via the quick-release interface.

4. The testing system according to claim 3, characterized in that, The first main oil circuit reversing pressure regulating valve group (18) and / or the second main oil circuit reversing pressure regulating valve group (19) are configured to have at least a first state, a second state and a third state; In the first state, the P port of the first main oil circuit reversing pressure regulating valve group (18) and / or the second main oil circuit reversing pressure regulating valve group (19) are connected to the PA1 port, and the PB1 port is connected to the T port, so as to drive the piston rod of the hydraulic cylinder under test to extend. In the second state, the P port of the first main oil circuit reversing pressure regulating valve group (18) and / or the second main oil circuit reversing pressure regulating valve group (19) are connected to the PB1 port, and the PA1 port is connected to the T port, so as to drive the piston rod of the hydraulic cylinder under test to retract. In the third state, the P port, PA1 port, PB1 port and T port of the first main oil circuit reversing pressure regulating valve group (18) and / or the second main oil circuit reversing pressure regulating valve group (19) are mutually cut off so that the hydraulic cylinder under test is kept in a predetermined position.

5. The testing system according to claim 4, characterized in that, A first bypass proportional relief valve (15) is provided on the bypass of the first main oil circuit reversing pressure regulating valve group (18), and a second bypass proportional relief valve (17) is provided on the bypass of the second main oil circuit reversing pressure regulating valve group (19). The first bypass proportional relief valve (15) and the second bypass proportional relief valve (17) are configured to work in conjunction with the electro-proportional pilot loading valves (1821, 1920) in the first main oil circuit reversing pressure regulating valve group (18) or the second main oil circuit reversing pressure regulating valve group (19) to perform pressure compensation regulation during the start-up pressure test.

6. The testing system according to claim 4, characterized in that, The first main oil circuit reversing pressure regulating valve group (18) includes a second cartridge valve (1812), a third cartridge valve (1813), a fourth cartridge valve (1814), a fifth cartridge valve (1815), a first pilot on / off valve (1822), and a second pilot on / off valve (1823). In the first state, the first pilot shut-off valve (1822) is not energized, the third cartridge valve (1813) and the fifth cartridge valve (1815) are closed, the second pilot shut-off valve (1823) is energized, and the second cartridge valve (1812) and the fourth cartridge valve (1814) are open. In the second state, the first pilot shut-off valve (1822) is energized, the third cartridge valve (1813) and the fifth cartridge valve (1815) are open, the second pilot shut-off valve (1823) is not energized, and the second cartridge valve (1812) and the fourth cartridge valve (1814) are closed. In the third state, neither the first pilot shut-off valve (1822) nor the second pilot shut-off valve (1823) is allowed to turn on, and the second cartridge valve (1812), the third cartridge valve (1813), the fourth cartridge valve (1814), and the fifth cartridge valve (1815) are closed.

7. The testing system according to claim 6, characterized in that, It also includes the first main oil circuit flow metering safety valve group (12); The first outlet (PA1) of the first main oil circuit flow metering safety valve group (12) is connected to the inlet of the first main oil circuit reversing pressure regulating valve group (18) to provide a pressure oil source for the inlet of the first main oil circuit reversing pressure regulating valve group (18). The second oil outlet (PA2) of the first main oil circuit flow metering safety valve group (12) is connected to the oil inlet of the first bypass proportional relief valve (15) through the first ball valve (14); The first bypass proportional relief valve (15) is configured to work in conjunction with the first main oil circuit reversing pressure regulating valve group (18) to regulate the system pressure of the first test branch when the first ball valve (14) is opened.

8. The testing system according to claim 7, characterized in that, The second main oil circuit reversing pressure regulating valve group (19) includes a second cartridge valve (1912), a third cartridge valve (1913), a fourth cartridge valve (1914), a fifth cartridge valve (1915), a first pilot on / off valve (1921), and a second pilot on / off valve (1922). In the first state, the first pilot shut-off valve (1921) is not energized, the third cartridge valve (1913) and the fifth cartridge valve (1915) are closed, the second pilot shut-off valve (1922) is energized, and the second cartridge valve (1912) and the fourth cartridge valve (1914) are open. In the second state, the first pilot shut-off valve (1921) is energized, the third cartridge valve (1913) and the fifth cartridge valve (1915) are open, the second pilot shut-off valve (1922) is not energized, and the second cartridge valve (1912) and the fourth cartridge valve (1914) are closed. In the third state, neither the first pilot shut-off valve (1921) nor the second pilot shut-off valve (1922) is energized, and the second cartridge valve (1912), the third cartridge valve (1913), the fourth cartridge valve (1914), and the fifth cartridge valve (1915) are closed.

9. The testing system according to claim 8, characterized in that, The third outlet (PB1) of the first main oil circuit flow metering safety valve group (12) is connected to the inlet of the second main oil circuit reversing pressure regulating valve group (19) to provide a pressure oil source for the second main oil circuit reversing pressure regulating valve group (19); The fourth oil outlet (PB2) of the first main oil circuit flow metering safety valve group (12) is connected to the oil inlet of the second bypass proportional relief valve (17) through the second ball valve (16); The second bypass proportional relief valve (17) is configured to work in conjunction with the second main oil circuit reversing pressure regulating valve group (19) to regulate the system pressure of the second test branch when the second ball valve (16) is opened.

10. The testing system according to claim 9, characterized in that, The inlet of the first main oil circuit flow metering safety valve group (12) is connected to the output oil circuit of the first main pump (3) and / or the second main pump (4), and the outlet of the first main oil circuit flow metering safety valve group (12) is connected to the inlet of the first main oil circuit reversing pressure regulating valve group (18) and / or the second main oil circuit reversing pressure regulating valve group (19). The first main oil circuit flow metering safety valve group (12) includes a valve block (121), a first safety protection unit and a second safety protection unit in parallel; The first safety protection unit includes a first two-way loading cartridge valve (1212), a first pilot loading valve (1213) for setting the pilot pressure of the first two-way loading cartridge valve (1212), and a first pressure shut-off valve (1214) connected in parallel with the first pilot loading valve (1213). The first safety protection unit is used to provide a pressure oil source for the first main oil circuit reversing pressure regulating valve group (18) and set the maximum safety pressure. The second safety protection unit includes a second two-way loading cartridge valve, a second pilot loading valve (1217) for setting the pilot pressure of the second two-way loading cartridge valve, and a second pressure shut-off valve (1218) connected in parallel with the second pilot loading valve (1217). The second safety protection unit is used to provide a pressure oil source for the second main oil circuit reversing pressure regulating valve group (19) and set the maximum safety pressure. The first main oil circuit flow metering safety valve group (12) also integrates a first flow meter (1219) and a first pressure sensor (1221), which are configured to monitor the flow rate and pressure of the oil flowing to the first main oil circuit reversing pressure regulating valve group (18); and a second flow meter (1220) and a second pressure sensor (1222), which are configured to monitor the flow rate and pressure of the oil flowing to the second main oil circuit reversing pressure regulating valve group (19).

11. The testing system according to claim 10, characterized in that, The first main oil circuit flow metering safety valve group (12) also includes a first internal control cartridge valve (1223) and a second internal control cartridge valve (1224). The control chambers of the first internally controlled cartridge valve (1223) and the second internally controlled cartridge valve (1224) are connected to a control oil circuit and the corresponding main oil circuit; The first internally controlled cartridge valve (1223) and the second internally controlled cartridge valve (1224) are configured to use the higher pressure between the control oil pressure and the main oil circuit pressure as the effective control pressure.

12. The testing system according to claim 11, characterized in that, The first main oil circuit reversing pressure regulating valve group (18) also includes a first cartridge valve (1811) and a sixth cartridge valve (1816). The first cartridge valve (1811) is connected between the first oil outlet (PA1) and the first oil return (T) of the valve block (181), and the sixth cartridge valve (1816) is connected between the second oil outlet (PB1) and the first oil return (T) of the valve block (181). When the first main oil circuit reversing pressure regulating valve group (18) is in the third state, the first cartridge valve (1811) and the sixth cartridge valve (1816) are both configured to be closed to cut off the connection between the first oil outlet (PA1) and the second oil outlet (PB1) and the return oil circuit. The testing system also includes multiple sets of measuring cylinders (33, 39, 45), each set of measuring cylinders being connected to the return oil branch of the first hydraulic cylinder A port integrated multi-pass block (25) or the first hydraulic cylinder B port integrated multi-pass block (46) through an independent leakage measuring valve; And / or, the second main oil circuit reversing pressure regulating valve group (19) further includes a first cartridge valve (1911) and a sixth cartridge valve (1916). The first cartridge valve (1911) is connected between port A (PA2) and return port (T) of the valve block (191), and the sixth cartridge valve (1916) is connected between port B (PB2) and return port (T) of the valve block (191). When the second main oil circuit reversing pressure regulating valve group (19) is in the third state, the first cartridge valve (1911) and the sixth cartridge valve (1916) are both controlled to be closed to cut off the connection between port A (PA2) and port B (PB2) and the return oil circuit. The testing system also includes multiple sets of measuring cylinders (56, 62, 68), each set of measuring cylinders being connected to the return oil branch of the second hydraulic cylinder A port integrated multi-pass block (49) or the second hydraulic cylinder B port integrated multi-pass block (70) through an independent leakage measuring valve (55, 61, 67); When conducting an internal leakage test, the corresponding leakage measurement valve is opened, so that the oil leaking from the piston of the hydraulic cylinder under test is directly guided to the corresponding measuring cylinder for volume measurement.

13. The testing system according to claim 12, characterized in that, When the first main oil circuit reversing pressure regulating valve group (18) is in the third state, the second cartridge valve (1812), the third cartridge valve (1813), the fourth cartridge valve (1814), the fifth cartridge valve (1815), the first cartridge valve (1811) and the sixth cartridge valve (1816) are all closed, so as to achieve complete isolation of all working oil ports (PA1, PB1) from the pressure source (P port), the return oil port (T port) and the pilot control oil circuit (X port) inside the valve group; And / or, when the second main oil circuit reversing pressure regulating valve group (19) is in the third state, the second cartridge valve (1912), the third cartridge valve (1913), the fourth cartridge valve (1914), the fifth cartridge valve (1915), the first cartridge valve (1911) and the sixth cartridge valve (1916) are all closed, so as to achieve complete isolation of all working oil ports (PA2, PB2) from the pressure source (P port), the return oil port (T port) and the pilot control oil circuit within the valve group.

14. The testing system according to claim 13, characterized in that, The first hydraulic cylinder A port integrated multi-pass block (25) and the first hydraulic cylinder B port integrated multi-pass block (46) each have three quick-release interfaces (28, 34, 40, 31, 37, 43) and are respectively provided with three independent leakage measurement branches; Each of the aforementioned leakage measurement branches includes a leakage measurement valve and a measuring cylinder (33, 39, 45) arranged in series. The leakage measurement branch is connected between the corresponding quick-release interface and the system return oil circuit, and the leakage measurement valve is located upstream of the measuring cylinder; And / or, the second hydraulic cylinder A port integrated multi-pass block (49) and the second hydraulic cylinder B port integrated multi-pass block (70) each have three quick-release interfaces (51, 57, 63, 54, 60, 66) respectively, and are provided with three independent leakage measurement branches; Each of the aforementioned leakage measurement branches includes a leakage measurement valve (55, 61, 67) and a measuring cylinder (56, 62, 68) arranged in series. The leakage measurement branch is connected between the corresponding quick-release interface and the system return oil line, and the leakage measurement valve is located upstream of the measuring cylinder.

15. The testing system according to claim 1, characterized in that, Also includes: The first control pump (2) has an input oil circuit connected to the oil tank (1) to provide control oil source; The first control oil pressure regulating safety valve group (13) is connected to the output oil circuit of the first control pump (2) to regulate and provide stable control oil. Accumulator (22), which is connected to the control oil line provided by the first control oil pressure regulating safety valve group (13).

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