Self-adaptive test system and method for hydraulic power unit

Abstract

The invention discloses a self-adaptive test system and method for a hydraulic power unit, and the system comprises a test bench which is provided with a fixing tool for fixing the tested hydraulic power unit; the oil tank unit is arranged in the test bed and is used for supplying oil to and pumping oil from the tested hydraulic power unit; and the counterweight test unit is arranged in the test bench, the counterweight test unit comprises a counterweight module, and the counterweight module is connected with a working oil port of a tested hydraulic power unit through a first oil path. The device is simple in structure, directly simulates the real gravity load borne by the hydraulic execution mechanism through the counterweight module, and can accurately test the lifting and descending dynamic performance and the pressure maintaining internal leakage characteristic of the power unit under the load condition. The problems that a traditional back pressure method cannot truly simulate the gravity load, and descending speed control and energy recovery performance are difficult to evaluate are effectively solved.

Description

Technical Field

[0001] This invention relates to the field of hydraulic power unit testing technology, specifically an adaptive testing system and method for hydraulic power units. Background Technology

[0002] As the core power source of a hydraulic system, the hydraulic power unit plays a crucial role in converting mechanical energy into hydraulic energy. Its performance directly determines the reliability, efficiency, and safety of mainframes in key fields such as construction machinery, agricultural equipment, and wind power. Therefore, comprehensive and accurate performance testing of the hydraulic power unit before it leaves the factory is essential.

[0003] Currently, the industry's commonly used testing method mainly relies on the "back pressure method," which applies a simulated load to the system through hydraulic valve assemblies to verify its basic parameters such as pressure and flow rate. However, this method has significant limitations: First, it cannot realistically simulate the descent of the hydraulic cylinder under the vehicle's own weight, making it difficult to accurately measure and evaluate the speed control performance and energy recovery characteristics of the power unit under gravity load; second, the numerous valves and pipelines in the test circuit can cause internal leakage, interfering with the accuracy of the pressure holding test results and leading to biases in the judgment of internal leakage. Therefore, an adaptive testing system and method for hydraulic power units is proposed. Summary of the Invention

[0004] The purpose of this invention is to provide an adaptive testing system and method for hydraulic power units to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an adaptive test system for a hydraulic power unit, comprising: A test bench, on which fixed fixtures are provided for fixing the hydraulic power unit under test; The oil tank unit is located inside the test bench and is used to supply and pump oil into the hydraulic power unit under test. The counterweight test unit is located inside the test bench. The counterweight test unit includes a counterweight module. The counterweight module is connected to the working oil port of the hydraulic power unit under test through a first oil circuit. It is used to simulate real gravity load to test the lifting and lowering performance of the hydraulic power unit under test under load and to perform pressure holding internal leakage test.

[0006] As a further aspect of the present invention: the fuel tank unit includes: The main oil tank contains hydraulic oil for testing; The oil injection module is connected to the main oil tank and the oil tank of the hydraulic power unit under test, respectively, and is configured to inject the hydraulic oil in the main oil tank into the oil tank of the hydraulic power unit under test. The oil extraction module is connected to both the main oil tank and the oil tank of the hydraulic power unit under test, and is configured to extract the hydraulic oil back into the main oil tank after the test is completed. A filter module, located on the main oil tank, is configured to filter the hydraulic oil in the main oil tank to maintain the cleanliness of the hydraulic oil.

[0007] As a further aspect of the present invention: the counterweight module includes a bracket and guide rods disposed at the four corners of the upper surface of the bracket. A bearing plate is provided between the four guide rods. The bearing plate is connected to the guide rods through bearings. A plurality of limiting rods are installed on the bearing plate. The limiting rods are used to limit the position of the counterweight. A test cylinder is installed inside the bracket. The rodless chamber of the test cylinder is connected to the first oil circuit, and the piston rod end of the test cylinder is connected to the bearing plate.

[0008] As a further aspect of the present invention, it also includes a back pressure testing unit, which comprises a bridge circuit, a fourth filter, and a proportional solenoid valve arranged sequentially along the hydraulic oil delivery path. The bridge circuit is connected to the hydraulic power unit under test via a quick-connect coupling, and the bridge circuit is configured to adapt to the testing of single-acting or double-acting hydraulic power units. The hydraulic power unit under test is equipped with an overflow valve, and the fourth filter is connected to the proportional solenoid valve. The fourth filter and the proportional solenoid valve are respectively connected to the bridge circuit.

[0009] As a further aspect of the present invention, it also includes a control unit, which is electrically connected to the counterweight test unit and the back pressure test unit, for controlling the test process, collecting test data, and performing fault diagnosis based on preset logic rules.

[0010] As a further aspect of the present invention, it also includes a comprehensive testing module comprising a connecting fixture mounted on a fixed fixture, the connecting fixture being positioned between the motor and the gear pump, the connecting fixture being equipped with torque and speed sensors for detecting the speeds of the motor and the gear pump respectively, and the control unit being connected to the torque and speed sensors for collecting and analyzing torque and speed data under different pressure loads to separately calculate the motor efficiency and gear pump efficiency.

[0011] As a further aspect of the present invention, it also includes an airtightness testing unit, which includes an air source and a pressure control element and a shut-off valve arranged along the air supply path of the air source. The shut-off valve is connected to the oil tank of the hydraulic power unit under test through a quick-connect coupling, and a safety valve is provided on the pipeline between the shut-off valve and the quick-connect coupling.

[0012] A method of using the testing system includes the following steps: S1. Fix the hydraulic power unit under test, perform factory tests on the hydraulic power unit under test, and execute the following tests in sequence: S11. The pressure is automatically adjusted by the proportional solenoid valve to test the opening pressure of the relief valve on the hydraulic power unit under test; if the opening pressure is not within the set range, the relief valve is manually adjusted until the required relief pressure value is reached. S12. The test cylinder is tested under full load conditions during the descent process. Based on the flow conversion result of the test cylinder, it is determined whether it meets the preset descent speed requirement. S13. Under full load conditions, run the test cylinder up and down continuously at least twice, measure the lifting height and related parameters within a given time, and evaluate whether it is qualified according to the judgment criteria. S14. Under full load, measure the amount of downward movement of the tested hydraulic power unit and the test cylinder within a given time, and determine whether it meets the specified qualification standard based on the amount of downward movement. During or after the factory test process, a preset fault diagnosis logic is executed based on the data collected in steps S11 to S13. S2. After completing the factory test, the tested hydraulic power unit shall undergo a type test, and the following tests shall be performed in sequence: S21. Use a proportional solenoid valve to automatically adjust the pressure, test the current, voltage and system flow of the hydraulic power unit under different pressure levels, and calculate the overall efficiency of the entire system through software. S22. After raising the test load to any position, stop the motor and keep it stationary for a first preset time. Then, detect the displacement change of the test cylinder within a second preset time. S23. After setting the relief valve to the specified pressure value, calculate the opening ratio of the relief valve by measuring the relief pressure. As a further aspect of the present invention: the preset fault diagnosis logic includes at least one of the following: Diagnostic Logic 1: Analyze the flow data collected near the set pressure point in step S11; if the system pressure is stable within the set pressure allowable range, but the measured flow value continues to exceed the standard flow allowable range corresponding to the set pressure, then generate diagnostic information indicating low overall efficiency of the motor and gear pump. Diagnostic Logic 2: Compare the measured descent time obtained in step S12 with the preset standard descent time threshold; if the measured descent time is less than the standard descent time threshold, generate diagnostic information indicating that the speed limit valve is missing or malfunctioning. When diagnostic logic one is triggered, a specific efficiency test is executed, which includes: Control the operation of the torque and speed sensor in the integrated test module; Torque and speed data were collected under multiple different pressure loads simulated by the back pressure test unit. Based on the data, the output efficiency of the motor and the volumetric efficiency of the gear pump are calculated respectively.

[0013] As a further aspect of the present invention, it also includes conducting an airtightness test on the oil tank of the hydraulic power unit under test before the factory testing process, and performing the following tests in sequence: S01. Connect the airtightness test unit to the oil tank of the hydraulic power unit under test; S02. Fill the oil tank with dry gas to the predetermined test pressure; S03. Turn off the air supply and maintain the pressure in the oil tank of the hydraulic power unit under test for a preset time. Monitor the pressure drop value. If the pressure drop value does not exceed the qualified threshold, the air tightness of the oil tank of the hydraulic power unit under test is deemed qualified.

[0014] Compared with the prior art, the beneficial effects of the present invention are: This application directly simulates the real gravity load borne by the hydraulic actuator through a counterweight module, enabling accurate testing of the lifting and lowering dynamic performance and pressure-holding internal leakage characteristics of the power unit under load conditions. This effectively solves the problems of traditional back-pressure methods, which cannot realistically simulate gravity loads and are difficult to evaluate descent speed control and energy recovery performance. Furthermore, by reducing the number of valve groups and connection points in the first oil circuit, the interference of system internal leakage on the test results is reduced, thus significantly improving the accuracy of pressure-holding tests and internal leakage detection. Simultaneously, the key parameters of the test cylinder are consistent with the actual actuator of the vehicle, ensuring a high degree of consistency between the test conditions and actual operation, making the test results more valuable for engineering reference. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the test system of the present invention; Figure 2 This is a schematic diagram of the hydraulic management of the test system of the present invention; Figure 3 This is a schematic diagram of the first oil circuit of the present invention; Figure 4 This is a schematic diagram of the hydraulic pipeline of the oil tank unit of the present invention; Figure 5 This is a schematic diagram of the hydraulic pipeline of the back pressure testing unit of the present invention; Figure 6 This is a schematic diagram of the hydraulic pipeline of the airtightness testing unit of the present invention; Figure 7 This is a schematic diagram of the counterweight module of the present invention; Figure 8 This is a schematic diagram of the fixing fixture of the present invention; Figure 9 This is a schematic diagram of the control unit of the present invention; In the diagram: 1. Test bench; 2. Fixture; 21. Connecting frame; 22. Pneumatic gripper; 3. Oil tank unit; 31. Main oil tank; 32. Oil injection module; 321. First filter; 322. First motor pump unit; 323. First check valve; 324. Second filter; 325. Reversing valve; 33. Oil extraction module; 331. Second motor pump unit; 332. Solenoid valve; 34. Filter module; 4. Counterweight test unit; 41. Counterweight module; 411. Bracket; 412. Guide rod; 413. Bearing plate; 414. Limiting rod; 415. Counterweight block; 416. Test 42. Cylinder; 42. First oil circuit; 421. Third filter; 422. First relief valve; 5. Back pressure test unit; 51. Bridge circuit; 511. Oil port one; 512. Oil port two; 513. Oil port three; 514. Oil port four; 515. Second check valve; 52. Fourth filter; 53. Proportional solenoid valve; 6. Control unit; 61. Data acquisition module; 62. Control module; 7. Comprehensive test module; 71. Torque and speed sensor; 72. Connecting fixture; 8. Air tightness test unit; 81. Air source; 82. Pressure control element; 83. Shut-off valve; 84. Safety valve. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Please see Figure 1-9 In this embodiment of the invention, an adaptive testing system for a hydraulic power unit includes: Test bench 1, on which a fixing fixture 2 is provided for fixing the hydraulic power unit under test; Oil tank unit 3 is located inside the test bench 1 and is used to supply and extract oil to the hydraulic power unit under test. The counterweight test unit 4 is set inside the test bench 1. The counterweight test unit 4 includes a counterweight module 41. The counterweight module 41 is connected to the working oil port of the hydraulic power unit under test through the first oil circuit 42. It is used to simulate real gravity load to test the lifting and lowering performance of the hydraulic power unit under test under load and to perform pressure holding internal leakage test.

[0018] Specifically, the hydraulic power unit consists of a gear pump, a motor, a control valve group, an oil tank, and pipelines. The hydraulic power unit is existing technology and will not be described in detail here. Several fixing fixtures 2 are installed on the test bench 1. The number of fixing fixtures 2 is not limited. In this embodiment, preferably, there are four fixing fixtures 2. The four fixing fixtures 2 are arranged in groups of two. The two groups of fixing fixtures 2 fix the horizontal hydraulic power unit and the vertical hydraulic power unit respectively. The fixing fixture 2 includes a connecting frame 21 and a pneumatic gripper 22 set on the connecting frame 21. The horizontal hydraulic power unit or the vertical hydraulic power unit is fixed by the pneumatic gripper 22.

[0019] The oil tank unit 3 is installed inside the test bench 1. After the fixing fixture 2 fixes the hydraulic power unit, the oil tank unit 3 is connected to the hydraulic power unit under test. The oil tank unit 3 supplies oil to the hydraulic power unit for subsequent testing of its lifting and lowering performance under load conditions, and performs internal leakage testing under pressure holding conditions.

[0020] The first oil circuit 42 includes a third filter 421, which is connected to a quick-connect coupling 10 via a pipeline. The quick-connect coupling 10 is connected to a hydraulic power unit. A pressure gauge 9 is installed at the quick-connect coupling 10 via the pipeline. The side of the third filter 421 away from the quick-connect coupling 10 is connected to a first relief valve 422 via a pipeline. The oil circuit structure of the first oil circuit 42 is simple, with fewer control valve groups and fewer leakage points than traditional test schemes, thereby effectively improving measurement accuracy. In addition, the cylinder used in the counterweight module 41 is consistent with the cylinder of the actual actuator of the vehicle in terms of key parameters such as diameter and sealing, which makes the vehicle highly consistent when detecting slippage and internal leakage, and the test results are more valuable.

[0021] Please see Figure 4 In one embodiment, preferably, the fuel tank unit 3 includes: The main oil tank 31 contains hydraulic oil for testing. The oil injection module 32 is connected to the main oil tank 31 and the hydraulic power unit under test respectively, and is configured to inject the hydraulic oil in the main oil tank 31 into the hydraulic power unit under test. Specifically, the oil filling module 32 includes a first filter 321 installed on the main oil tank 31. A pipeline passing through the first filter 321 and entering the main oil tank 31 is installed on the first filter 321. The first filter 321 is connected to a first motor pump unit 322 via the pipeline. The outlet of the first motor pump unit 322 is connected to a first check valve 323 via a pipeline. The first check valve 323 is connected to a second filter 324 via a pipeline. The second filter 324 is then connected to a reversing valve 325 via a pipeline. The reversing valve 325 is connected to... The pipeline and pipe joints are connected to the hydraulic power unit. The first motor pump group 322 can generate suction to draw the hydraulic oil in the main oil tank 31 into the hydraulic power unit. The oil is filtered through two stages, namely the first filter 321 and the second filter 324, to ensure the cleanliness of the hydraulic oil entering the unit. The oil supply is controlled by the reversing valve 325. This pipeline structure ensures that the hydraulic oil has good cleanliness and a stable flow direction before entering the hydraulic power unit under test, and at the same time facilitates quick connection and disassembly of the test equipment.

[0022] The oil extraction module 33 is connected to the main oil tank 31 and the hydraulic power unit under test, respectively, and is configured to extract the hydraulic oil back into the main oil tank 31 after the test is completed. Specifically, the oil extraction module 33 includes a second motor pump unit 331, which is connected to the main oil tank 31 via a pipeline. The second motor pump unit 331 is also connected to a solenoid valve 332 via a pipeline. The solenoid valve 332 is connected to the hydraulic power unit via a pipeline and a pipeline connector. When the second motor pump unit 331 is working, it can pump the hydraulic oil in the tested hydraulic power unit back to the main oil tank 31 via the pipeline.

[0023] The filter module 34 is installed on the main oil tank 31 and is configured to filter the hydraulic oil in the main oil tank 31 to maintain the cleanliness of the hydraulic oil. Furthermore, the filter module 34 is existing technology and will not be described in detail here. It can provide hydraulic oil that meets the cleanliness requirements for the testing of hydraulic power units and avoid contamination and damage to the tested unit.

[0024] Please see Figure 7In one embodiment, preferably, the counterweight module 41 includes a bracket 411 and guide rods 412 disposed at the four corners of the upper surface of the bracket 411. A bearing plate 413 is disposed between the four guide rods 412. The bearing plate 413 is connected to the guide rods 412 via bearings. A plurality of limiting rods 414 are installed on the bearing plate 413. The limiting rods 414 are used to limit the position of the counterweight block 415. A test cylinder 416 is installed inside the bracket 411. The rodless chamber of the test cylinder 416 is connected to the first oil circuit 42, and the piston rod end of the test cylinder 416 is connected to the bearing plate 413. Furthermore, when the test cylinder 416 is started, its piston rod pushes the bearing plate 413. The plate 413 moves up or down, and different loads can be simulated by increasing or decreasing the number of counterweights 415 on the bearing plate 413. The limiting rod 414 is used to limit the position of the counterweights 415 and prevent the counterweights 415 from shifting. When it is necessary to adjust the number of counterweights 415, the threaded sleeve installed on the upper end of the limiting rod 414 can be rotated. The threaded sleeve is threadedly connected to the limiting rod 414. After the threaded sleeve is disengaged from the limiting rod 414, the number of counterweights 415 can be replaced or adjusted. The counterweight module 41 is used to test the lifting and lowering performance of the hydraulic power unit under real load and to conduct pressure holding internal leakage tests. The test conditions are highly consistent with the actual operation of the vehicle.

[0025] Please see Figure 5 In one embodiment, preferably, it further includes a back pressure test unit 5. The back pressure test unit 5 includes a bridge circuit 51, a fourth filter 52, and a proportional solenoid valve 53 arranged sequentially along the hydraulic oil delivery path. The bridge circuit 51 is connected to the hydraulic power unit under test through a quick-connect coupling, and the bridge circuit 51 is configured to adapt to the testing of single-acting or double-acting hydraulic power units. The hydraulic power unit under test is provided with a second relief valve. The fourth filter 52 is connected to the proportional solenoid valve 53, and the fourth filter 52 and the proportional solenoid valve 53 are respectively connected to the bridge circuit 51.

[0026] Specifically, the bridge circuit 51 has four oil ports: port 1 (511), port 2 (512), port 3 (513), and port 4 (514). Adjacent oil ports are connected by pipelines, and each pipeline is equipped with a second check valve 515. The second check valve 515 restricts the direction of hydraulic oil movement. Ports 1 (511) and 4 (514) are connected to quick-connect couplings 10 via pipelines. Each quick-connect coupling 10 is connected to one of two hydraulic power units. A pressure gauge 9 is installed at each quick-connect coupling 10. During back pressure testing, for a double-acting hydraulic power unit, the following oil circuit path can be used: Hydraulic oil enters the pipeline from the first hydraulic power unit under test through quick-connect coupling 10, reaches port 1 511, flows through the internal second check valve 515 to port 2 512, then flows through the fourth filter 52 and proportional solenoid valve 53 in sequence, and then returns to port 1 511 through port 4 514 and another check valve, and finally flows back to the first hydraulic power unit. Hydraulic oil enters the pipeline from the second hydraulic power unit under test through quick-connect coupling 10, reaches port 3 513, flows through the internal check valve to port 2 512, then flows through the fourth filter 52 and proportional solenoid valve 53 in sequence, and then returns to port 3 513 through port 4 514 via the check valve, and finally flows back to the second hydraulic power unit.

[0027] For single-acting hydraulic power units, the back pressure test can be completed using any of the oil circuit methods in the above-mentioned double-acting test. This structural design allows the back pressure test unit 5 to flexibly adapt to the test requirements of different types of hydraulic power units, and ensures the cleanliness of the oil through the fourth filter 52. At the same time, the back pressure value is precisely adjusted through the proportional solenoid valve 53, thereby achieving efficient and reliable back pressure performance evaluation.

[0028] Please see Figure 9In one embodiment, preferably, it further includes a control unit 6, electrically connected to the counterweight testing unit 4, back pressure testing unit 5, comprehensive testing module 7, and airtightness testing unit 8. This control unit 6 controls the testing process, collects test data, and performs fault diagnosis based on preset logic rules. The control unit 6 includes a data acquisition module 61 and a control module 62. The data acquisition module 61 collects data from sensors in the hydraulic circuit, such as pressure and flow rates, and compares this data with preset target values. Based on this deviation, it adjusts the output current using an adaptive PID algorithm, enabling the actual pressure to respond quickly and stably track multiple different target pressure setpoints. This achieves high-precision, high-response pressure closed-loop control. This adaptive closed-loop control mechanism significantly improves the automation level of the testing process, effectively reduces human intervention and operational errors, and improves test repeatability and efficiency. The data acquisition module 61 can automatically analyze and diagnose test data, meeting the needs of equipment status monitoring and anomaly tracing in daily production. It helps operators locate the root cause of problems in the first instance, reducing reliance on operators' experience and technical skills. The control module 62 also has the function of writing test procedures based on test items and automatically generating analysis reports, thereby determining the type and cause of faults and facilitating subsequent maintenance. The control unit 6 not only realizes the automated control of the test process, but also has built-in data processing, analysis, and fault diagnosis functions based on preset logic. The system can process test data in real time and make preliminary anomaly judgments, quickly locate fault sources such as inefficiency and component failure, and automatically generate analysis reports. This greatly reduces reliance on operators' experience and provides efficient and reliable data support for subsequent in-depth product performance analysis, quality traceability, and preventive maintenance.

[0029] Please see Figure 8 In one embodiment, preferably, the system further includes a comprehensive testing module 7 comprising a connecting fixture 71 mounted on a fixed fixture 2. The connecting fixture 71 is positioned between the motor and the gear pump. The connecting fixture 71 is equipped with torque and speed sensors 72 that detect the speeds of the motor and the gear pump, respectively. The control unit 6 is connected to the torque and speed sensors 72 and is used to collect and analyze torque and speed data under different pressure loads to separately calculate the motor efficiency and the gear pump efficiency.

[0030] Specifically, the torque and speed sensor 72 is connected to the motor output shaft and the gear pump input shaft through the connecting fixture 71 to obtain torque and speed information in real time during the transmission process; the motor output power (torque × speed) and gear pump input power (torque × speed) are calculated through the torque and speed data, thereby accurately separating and calculating the motor efficiency and gear pump efficiency to determine the source of the fault. The control and data acquisition module 61 processes and analyzes the data to determine whether the fault source is from the motor or the gear pump.

[0031] Please see Figure 6 In one embodiment, preferably, it further includes an air tightness test unit 8. The air tightness test unit 8 includes an air source 81 and a pressure control element 82 and a shut-off valve 83 arranged along the air supply path of the air source 81. The shut-off valve 83 is connected to the oil tank of the hydraulic power unit under test through a quick-connect coupling. A safety valve 84 is provided on the pipeline between the shut-off valve 83 and the quick-connect coupling.

[0032] Specifically, the pressure control element 82 can connect to several shut-off valves 83, and each shut-off valve 83 can be connected to the hydraulic power unit under test via a quick connector. The number of hydraulic power units under test is the same as the number of shut-off valves 83, and a safety valve 84 is installed on the pipeline between each hydraulic power unit under test and the shut-off valve 83. In this embodiment, there are two hydraulic power units under test. By inserting their corresponding quick-connect fittings into the oil tanks corresponding to the hydraulic power units under test, the gas pressure is controlled by the air source 81 via the pressure control element 82 to slowly fill the oil tanks under test to the target pressure value of 30 kPa. Then, the air source 81 is turned off, and the pressure is maintained for 30 seconds. The pressure change is monitored in real time by the pressure control element 82. The pressure decay is required to be no more than 3.3%, that is, the decay is ≤1.0 kPa at 30 kPa, which is considered qualified. If the decay exceeds 3.3%, it is considered unqualified.

[0033] Please see Figure 1-9 A method for using a testing system includes the following steps: S1. Fix the hydraulic power unit under test, perform factory tests on the hydraulic power unit under test, and execute the following tests in sequence: S11. The pressure is automatically adjusted by the proportional solenoid valve 53 to test the opening pressure of the second relief valve on the hydraulic power unit under test; if the opening pressure is not within the set range, the second relief valve is manually adjusted until the required relief pressure value is reached. S12. The test cylinder 416 is tested under full load conditions for descent under the action of counterweight. Based on the flow conversion result of the test cylinder 416, it is determined whether it meets the preset descent speed requirement. S13. Under full load conditions, make the test cylinder 416 run up and down continuously at least twice, measure the lifting height and related parameters within a given time, and evaluate whether it is qualified according to the judgment criteria. S14. Under full load, measure the amount of downward movement of the tested hydraulic power unit and test cylinder 416 within a given time, and determine whether it meets the specified qualification standard based on the amount of downward movement. During or after the factory test process, the preset fault diagnosis logic is executed based on the data collected in steps S11 to S13. S2. After completing the factory test, the tested hydraulic power unit shall undergo a type test, and the following tests shall be performed in sequence: S21. Use proportional solenoid valve 53 to automatically adjust the pressure, test the current, voltage and system flow of the hydraulic power unit under different pressure levels, and calculate the overall efficiency of the entire system through software; Overall efficiency = the ratio of the actual power of the gear pump to the input power of the motor. This allows for the calculation of efficiency under different pressures, thereby achieving the goal of testing the performance of the gear pump.

[0034] S22. After raising the test load to any position, stop the motor and keep it stationary for a first preset time. Then, detect the displacement change of the test cylinder 416 within a second preset time. S23. After setting the second relief valve to the specified pressure value, calculate the opening ratio of the second relief valve by measuring the relief pressure.

[0035] Please see Figure 1-9 In one embodiment, preferably, the preset fault diagnosis logic includes at least one of the following: Diagnostic Logic 1: Analyze the flow data collected near the set pressure point in step S11; if the system pressure is stable within the set pressure allowable range, but the measured flow value continues to exceed the standard flow allowable range corresponding to the set pressure, then generate diagnostic information indicating low overall efficiency of the motor and gear pump. Diagnostic Logic 2: Compare the measured descent time obtained in step S12 with the preset standard descent time threshold; if the measured descent time is less than the standard descent time threshold, generate diagnostic information indicating that the speed limit valve is missing or malfunctioning. When diagnostic logic one is triggered, a specific efficiency test is executed. This specific efficiency test includes: The torque and speed sensor 72 in the integrated test module 7 is controlled to operate. Torque and speed data were collected under multiple different pressure loads simulated in back pressure test unit 5; Based on the data, the output efficiency of the motor and the volumetric efficiency of the gear pump were calculated respectively.

[0036] Please see Figure 1 In one embodiment, preferably, the test further includes an airtightness test on the oil tank of the hydraulic power unit under test before the factory testing process, and the following tests are performed in sequence: S01. Connect the airtightness test unit 8 to the oil tank of the hydraulic power unit under test. S02. Fill the oil tank with dry gas to the predetermined test pressure; S03. Turn off the air source 81, maintain the pressure in the oil tank of the hydraulic power unit under test for a preset time, and monitor the pressure decay value. If the pressure decay value does not exceed the qualified threshold, the air tightness of the oil tank of the hydraulic power unit under test is determined to be qualified.

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

[0038] Therefore, the above description is only a preferred embodiment of this application and is not intended to limit the scope of this application; that is, all equivalent modifications made in accordance with the scope of the claims of this application shall be within the protection scope of the claims of this application.

Claims

1. An adaptive testing system for a hydraulic power unit, characterized in that, include: A test bench, on which fixed fixtures are provided for fixing the hydraulic power unit under test; The oil tank unit is located inside the test bench and is used to supply and pump oil into the hydraulic power unit under test. The counterweight test unit is located inside the test bench. The counterweight test unit includes a counterweight module. The counterweight module is connected to the working oil port of the hydraulic power unit under test through a first oil circuit. It is used to simulate real gravity load to test the lifting and lowering performance of the hydraulic power unit under test under load and to perform pressure holding internal leakage test.

2. The adaptive test system for the hydraulic power unit according to claim 1, characterized in that, The fuel tank unit includes: The main oil tank contains hydraulic oil for testing; The oil injection module is connected to the main oil tank and the oil tank of the hydraulic power unit under test, respectively, and is configured to inject the hydraulic oil in the main oil tank into the oil tank of the hydraulic power unit under test. The oil extraction module is connected to both the main oil tank and the oil tank of the hydraulic power unit under test, and is configured to extract the hydraulic oil back into the main oil tank after the test is completed. A filter module, located on the main oil tank, is configured to filter the hydraulic oil in the main oil tank to maintain the cleanliness of the hydraulic oil.

3. The adaptive test system for the hydraulic power unit according to claim 1, characterized in that, The counterweight module includes a bracket and guide rods located at the four corners of the upper surface of the bracket. A bearing plate is provided between the four guide rods. The bearing plate is connected to the guide rods through bearings. Several limiting rods are installed on the bearing plate to limit the position of the counterweight. A test cylinder is installed inside the bracket. The rodless chamber of the test cylinder is connected to the first oil circuit, and the end of the piston rod of the test cylinder is connected to the bearing plate.

4. The adaptive test system for the hydraulic power unit according to claim 3, characterized in that, It also includes a back pressure testing unit, which comprises a bridge circuit, a fourth filter, and a proportional solenoid valve arranged sequentially along the hydraulic oil delivery path. The bridge circuit is connected to the hydraulic power unit under test via a quick-connect coupling, and the bridge circuit is configured to adapt to the testing of single-acting or double-acting hydraulic power units. The hydraulic power unit under test is equipped with an overflow valve. The filter is connected to the proportional solenoid valve, and the fourth filter and the proportional solenoid valve are respectively connected to the bridge circuit.

5. The adaptive test system for a hydraulic power unit according to claim 4, characterized in that, It also includes a control unit, which is electrically connected to the counterweight test unit and the back pressure test unit, for controlling the test process, collecting test data, and performing fault diagnosis based on preset logic rules.

6. The adaptive test system for a hydraulic power unit according to claim 5, characterized in that, It also includes a comprehensive testing module, which includes a connecting fixture mounted on a fixed fixture. The connecting fixture is located between the motor and the gear pump. The connecting fixture is equipped with torque and speed sensors that detect the speeds of the motor and the gear pump respectively. The control unit is connected to the torque and speed sensors and is used to collect and analyze torque and speed data under different pressure loads to separately calculate the efficiency of the motor and the efficiency of the gear pump.

7. The adaptive test system for a hydraulic power unit according to claim 6, characterized in that, It also includes an airtightness testing unit, which includes an air source and a pressure control element and a shut-off valve arranged along the air supply path of the air source. The shut-off valve is connected to the oil tank of the hydraulic power unit under test through a quick-connect coupling, and a safety valve is provided on the pipeline between the shut-off valve and the quick-connect coupling.

8. A method using the testing system as described in claim 7, characterized in that, Includes the following steps: S1. Fix the hydraulic power unit under test, perform factory tests on the hydraulic power unit under test, and execute the following tests in sequence: S11. The pressure is automatically adjusted by the proportional solenoid valve to test the opening pressure of the relief valve on the hydraulic power unit under test; if the opening pressure is not within the set range, the relief valve is manually adjusted until the required relief pressure value is reached. S12. The test cylinder is tested under full load conditions during the descent process. Based on the flow conversion result of the test cylinder, it is determined whether it meets the preset descent speed requirement. S13. Under full load conditions, run the test cylinder up and down continuously at least twice, measure the lifting height and related parameters within a given time, and evaluate whether it is qualified according to the judgment criteria. S14. Under full load, measure the amount of downward movement of the tested hydraulic power unit and the test cylinder within a given time, and determine whether it meets the specified qualification standard based on the amount of downward movement. During or after the factory test process, a preset fault diagnosis logic is executed based on the data collected in steps S11 to S14. S2. After completing the factory test, the tested hydraulic power unit shall undergo a type test, and the following tests shall be performed in sequence: S21. Use a proportional solenoid valve to automatically adjust the pressure, test the current, voltage and system flow of the hydraulic power unit under different pressure levels, and calculate the overall efficiency of the entire system through software. S22. After raising the test load to any position, stop the motor and keep it stationary for a first preset time. Then, detect the displacement change of the test cylinder within a second preset time. S23. After setting the relief valve to the specified pressure value, calculate the opening ratio of the relief valve by measuring the relief pressure.

9. The test method according to claim 8, characterized in that, The preset fault diagnosis logic includes at least one of the following: Diagnostic Logic 1: Analyze the flow data collected near the set pressure point in step S11; if the system pressure is stable within the set pressure allowable range, but the measured flow value continues to exceed the standard flow allowable range corresponding to the set pressure, then generate diagnostic information indicating low overall efficiency of the motor and gear pump. Diagnostic Logic 2: Compare the measured descent time obtained in step S12 with the preset standard descent time threshold; if the measured descent time is less than the standard descent time threshold, generate diagnostic information indicating that the speed limit valve is missing or malfunctioning. When diagnostic logic one is triggered, a specific efficiency test is executed, which includes: Control the operation of the torque and speed sensor in the integrated test module; Torque and speed data were collected under multiple different pressure loads simulated by the back pressure test unit. Based on the data, the output efficiency of the motor and the volumetric efficiency of the gear pump are calculated respectively.

10. The test method according to claim 8, characterized in that, This also includes conducting an airtightness test on the oil tank of the hydraulic power unit under test before the factory testing process, and performing the following tests in sequence: S01. Connect the airtightness test unit to the oil tank of the hydraulic power unit under test; S02. Fill the oil tank with dry gas to the predetermined test pressure; S03. Turn off the air supply and maintain the pressure in the oil tank of the hydraulic power unit under test for a preset time. Monitor the pressure drop value. If the pressure drop value does not exceed the qualified threshold, the air tightness of the oil tank of the hydraulic power unit under test is deemed qualified.

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