Hydraulic direction valve test system and method

Abstract

The invention provides a hydraulic direction valve test system and method. The hydraulic direction valve test system comprises a hydraulic pump station system used for providing hydraulic power in the test process; the hydraulic pump station system comprises an oil tank system, a first main pump motor set system and a second main pump motor set system are connected to the oil tank system in parallel, the first main pump motor set system is used for providing hydraulic power for the first test system, and the second main pump motor set system is used for providing hydraulic power for the second test system; the oil tank system is connected with a control pump motor set system, and the control pump motor set system is used for providing hydraulic power for the third test system; and the first test system, the second test system and the third test system are connected with a control valve test bed system for testing a valve to be tested. Through the test system, different functions of different valves can be tested.

Description

Technical Field

[0001] The invention relates to the technical field of performance detection of hydraulic systems in hydropower stations, and in particular to a hydraulic directional valve test system and method. Background Art

[0002] The hydraulic system of a hydropower station is an important power unit and control unit for opening and closing the gates of the hydropower station. The hydraulic control valve is the smallest unit of the hydraulic system, and its quality directly determines the safety and reliability of the hydraulic system itself. Therefore, understanding the performance indicators of different valve groups and performing performance tests on different valves can greatly assist the equipment management department to understand the status of the hydraulic control valve, and then carry out planned inspection and maintenance work.

[0003] At present, maintenance personnel only rely on experience to judge valve failure and performance, or determine whether the valve is normal after installation by whether it can meet the on-site working conditions. Without specific data analysis, it is impossible to determine whether there is a problem with the newly purchased valve, and there is no quantitative data support for the actual performance of the old valve after removal. Summary of the invention

[0004] Based on the deficiencies in the above-mentioned prior art, the technical problem to be solved by the present invention is to provide a hydraulic directional valve test system and method. This system takes the test and detection of electromagnetic reversing valves, electromagnetic ball valves, and proportional reversing valves used in power stations as the starting point, and designs a hydraulic control valve test system. Through this test system, different functions of different valves can be tested, including internal leakage test and steady-state pressure difference-flow characteristic test of electromagnetic reversing valves and electromagnetic ball valves; internal leakage test, output flow-input signal characteristic test, threshold characteristic test, throttling adjustment characteristic test, output flow-load pressure difference characteristic test, output flow-valve pressure drop characteristic test, limit power characteristic test, pressure zero drift, fault protection function test, dynamic test and other parameters of servo valves and proportional valves. Different valves can be tested on one test system, which is helpful to understand whether the performance of old valves and newly purchased valves meet on-site requirements and quality evaluation, and greatly assists the maintenance and repair of hydraulic equipment.

[0005] In order to achieve the above technical features, the object of the present invention is achieved as follows: a hydraulic directional valve test system includes a hydraulic pump station system for providing hydraulic power during the test process; The hydraulic pump station system includes an oil tank system, and the oil tank system is connected in parallel with a first main pump motor system and a second main pump motor system, the first main pump motor system is used to provide hydraulic power for the first test system, and the second main pump motor system is used to provide hydraulic power for the second test system; the oil tank system is connected with a control pump motor system, and the control pump motor system is used to provide hydraulic power for the third test system; The first test system, the second test system and the third test system are connected to a control valve test bench system for testing the valve to be tested.

[0006] Preferably, the entire hydraulic pump station system is arranged inside the valve station pump station room; The oil tank system includes a main oil tank, which is provided with multiple oil drain ball valves, multiple groups of heaters are arranged inside the main oil tank, and the main oil tank is also equipped with a liquid level sensor, a visual liquid level gauge, a temperature sensor, an oil return filter, an oil filling filter and an oil sampling ball valve.

[0007] Preferably, the main oil tank is connected to a cooling circulation device for cooling the oil, and the cooling circulation device includes a switch signaling ball valve connected to the main oil tank, the switch signaling ball valve is connected to the cooling pump motor unit through a first flexible joint, the outlet of the cooling pump motor unit is connected to the cooler through a first one-way valve, the outlet of the cooler is connected in parallel with a first ball valve, and the first ball valve is connected to the main oil tank through a filter.

[0008] Preferably, the cooler adopts a plate cooler, which is connected to a water inlet ball valve for cooling water to enter, an electromagnetic water valve is installed on the pipeline after the water inlet ball valve, and the cooling water outlet of the cooler is connected to a water outlet ball valve.

[0009] Preferably, the first main pump motor group system includes a first oil suction ball valve connected to the main oil tank, the first oil suction ball valve is connected to the first pump group through a second flexible joint, the oil outlet of the first pump group is connected to the first high-pressure filter, and the first high-pressure filter is connected to the first test system through a second one-way valve and a first outlet ball valve in turn; a first seismic-resistant pressure gauge and a first electromagnetic overflow valve are installed on the pipeline between the first high-pressure filter and the second one-way valve; a first proportional overflow valve, a first pressure sensor and a connecting ball valve are installed on the pipeline between the second one-way valve and the first outlet ball valve, and the other end of the connecting ball valve is connected to the second test system.

[0010] Preferably, the second main pump motor group system includes a second oil suction ball valve connected to the main oil tank, the second oil suction ball valve is connected to the second pump group through a third flexible joint, the oil outlet of the second pump group is connected to the second high-pressure filter, and the second high-pressure filter is connected to the second test system through a third one-way valve and a second outlet ball valve in turn; a second seismic-resistant pressure gauge and a second electromagnetic overflow valve are installed on the pipeline between the second high-pressure filter and the third one-way valve; the pipeline between the third one-way valve and the second outlet ball valve is connected to the ball valve and is installed with a second pressure sensor.

[0011] Preferably, the control pump motor group system includes a third oil suction ball valve connected to the main oil tank, the third oil suction ball valve is connected to the third pump group through a fourth flexible joint, the oil outlet of the third pump group is connected to the third high-pressure filter, and the third high-pressure filter is connected to the third test system through a fourth one-way valve and a third outlet ball valve in turn; a third seismic-resistant pressure gauge and a third electromagnetic overflow valve are installed on the pipeline between the third pump group and the third high-pressure filter; a second proportional overflow valve and a third pressure sensor are installed on the pipeline between the fourth one-way valve and the third outlet ball valve.

[0012] Preferably, the first pump group adopts a constant pressure variable displacement plunger pump and is connected to a first drive motor to provide pump oil power; The second pump group adopts a constant pressure variable displacement plunger pump and is connected to a second drive motor to provide pump oil power; The third pump group adopts a constant pressure variable displacement pump and is connected to the third drive motor to provide oil pumping power.

[0013] Preferably, the control valve test bench system is arranged in a valve test laboratory, and the valve test laboratory is connected to the valve platform pump station room through a hydraulic pipeline; The control valve test bench system includes a second ball valve connected to the first test system port, and the pipeline after the second ball valve is connected to the P oil port of the valve to be tested through a seventh ball valve; It also includes a third ball valve connected to the second test system port, and the pipeline after the third ball valve is connected to the P oil port of the valve to be tested through a seventh ball valve; It also includes a fourth ball valve connected to the third test system port, the fourth ball valve being connected to the X oil port of the valve to be tested through the pressure reducing valve and the sixth ball valve; The pipeline between the third ball valve and the seventh ball valve is connected with a bypass flow regulating component and a seventeenth ball valve, the pipeline after the seventeenth ball valve is connected to the B oil port of the valve to be tested through the second flow meter, the fifteenth ball valve and the eleventh ball valve in sequence, and the B oil port of the valve to be tested is connected to a cavity of the dynamic measuring cylinder through the eighth ball valve; The A oil port of the valve to be tested is connected to the thirteenth ball valve, the twelfth ball valve and the ninth ball valve at the same time; the thirteenth ball valve is connected to the B oil port of the valve to be tested through the throttling loading assembly and the twentieth ball valve; the twelfth ball valve is connected to the oil return line through the sixteenth ball valve, the first flow meter and the eighteenth ball valve in sequence; the ninth ball valve is connected to another cavity of the dynamic measuring cylinder; The T oil port of the valve to be tested is connected to the 21st ball valve and the 14th ball valve at the same time, and the 21st ball valve is connected to the oil return pipeline; the 14th ball valve is connected to the Y oil port of the valve to be tested through the 10th ball valve, and is connected to the main oil tank of the control pump motor system through the 5th ball valve; The pipeline after the fourth ball valve is connected to the first accumulator through the first safety stop valve group, and the first safety stop valve group is also connected to the oil return pipeline; The T oil port of the valve to be tested is connected to the second accumulator through the twenty-third ball valve and the second safety shut-off valve group, and the second safety shut-off valve group is simultaneously connected to the P oil port of the valve to be tested through the twenty-second ball valve.

[0014] Preferably, the bypass flow regulating assembly comprises a third proportional throttle valve and an electromagnetic reversing valve connected in parallel, and the other ports of the third proportional throttle valve and the electromagnetic reversing valve are connected to the oil return pipeline.

[0015] Preferably, the throttling loading assembly includes a first proportional throttle valve, a second proportional throttle valve, a first electromagnetic reversing valve and a nineteenth ball valve connected in parallel.

[0016] On the other hand, the present invention provides a method for testing the performance of a valve to be tested using the hydraulic directional valve test system, including testing of an electromagnetic reversing valve and an electromagnetic ball valve: Internal leakage test, the oil flows from the P port to the T port of the valve to be tested: Step 1.1, open the second ball valve, the seventh ball valve, the fourteenth ball valve, the fifteenth ball valve and the eighteenth ball valve; Step 1.2, open the first outlet ball valve, close the connecting ball valve and the second outlet ball valve, start the first pump group, adjust the first proportional relief valve to set the test pressure, and adjust the third proportional throttle valve to set the test flow; Step 1.3, the test valve is powered on or off to close the oil port from P to T, and the internal leakage is detected by the second flow meter; Internal leakage test, the oil flows from the P port to the A port of the valve to be tested: Step 2.1, open the second ball valve, the seventh ball valve, the twelfth ball valve, the fifteenth ball valve, and the eighteenth ball valve; Step 2.2, open the first outlet ball valve, close the connecting ball valve and the second outlet ball valve, start the first pump group, adjust the first proportional relief valve to set the test pressure, and adjust the third proportional throttle valve to set the test flow; Step 2.3, the test valve is powered on or off to close the oil port P to the oil port A, and the internal leakage is detected by the second flow meter; Internal leakage test, the oil flows from the P port to the B port of the valve to be tested: Step 3.1, open the second ball valve, the seventh ball valve, the eleventh ball valve, the fifteenth ball valve, and the eighteenth ball valve; Step 3.2, open the first outlet ball valve, close the connecting ball valve and the second outlet ball valve, start the first pump group, adjust the first proportional relief valve to set the test pressure, and adjust the third proportional throttle valve to set the test flow; Step 3.3, the test valve is powered on or off to close the oil port from P to B, and the internal leakage is detected by the second flow meter; Steady-state pressure difference-flow characteristic test: Step 4.1, open the second ball valve, the seventh ball valve, the thirteenth ball valve, the twentieth ball valve, the nineteenth ball valve, the fourteenth ball valve, the sixteenth ball valve, and the eighteenth ball valve; If it is a three-way valve, open the second ball valve, the seventh ball valve, the thirteenth ball valve, the twentieth ball valve, the eleventh ball valve, the sixteenth ball valve, and the eighteenth ball valve; Step 4.2, open the first outlet ball valve, close the connecting ball valve and the second outlet ball valve, start the first pump group, adjust the first proportional relief valve to set the test pressure, and adjust the third proportional throttle valve to fully open the valve port for diversion; Step 4.3, closing the first proportional throttle valve and the second proportional throttle valve; Step 4.4, the valve to be tested is powered on or off to make the valve port connected, and a signal is input to the third proportional throttle valve to gradually reduce the diversion flow, and the flow of the valve to be tested is gradually increased from zero. The pressure difference-flow characteristic curve is plotted with the output flow as the X-axis and the pressure difference as the Y-axis.

[0017] On the other hand, the present invention provides a method for performing a performance test of a valve to be tested using the hydraulic directional valve test system, including a servo valve and a proportional valve test: Internal leakage test: Step 5.1, open the second ball valve, the seventh ball valve, the fourteenth ball valve, the fifteenth ball valve, and the eighteenth ball valve; Step 5.2, open the first outlet ball valve, close the connecting ball valve and the second outlet ball valve, start the first pump group, and adjust the first proportional relief valve to set the test pressure; Step 5.3, open the connecting ball valve, the fourth ball valve, and the sixth ball valve, start the third pump group, adjust the second proportional relief valve and the pressure reducing valve to set the pilot control oil pressure, and adjust the third proportional throttle valve to set the test flow; Step 5.4, input a periodic signal to the valve to be tested, detect the leakage of the T oil port through the second flow meter, open the tenth ball valve and the twenty-first ball valve, close the fifth ball valve and the fourteenth ball valve, and detect the leakage of the Y oil port through the second flow meter; Output flow-input signal characteristic test under constant valve pressure drop: Step 6.1, open the second ball valve, the seventh ball valve, the thirteenth ball valve, the nineteenth ball valve, the twentieth ball valve, the fourteenth ball valve, the sixteenth ball valve, the eighteenth ball valve, and the fifth ball valve; Step 6.2, open the first outlet ball valve, close the connecting ball valve and the second outlet ball valve, start the first pump group, and adjust the first proportional relief valve to set the test pressure; Step 6.3, open the third outlet ball valve, the fourth ball valve, and the sixth ball valve, start the third pump group, adjust the second proportional relief valve and the pressure reducing valve to set the pilot control oil pressure, and adjust the third proportional throttle valve to set the test flow; Step 6.4, closing the first proportional throttle valve and the second proportional throttle valve; Step 6.5, input a periodic signal to the valve to be tested, and draw its output flow-input signal characteristic curve with the given signal percentage as the X-axis and the flow signal as the Y-axis; Threshold characteristic test: Step 7.1, open the second ball valve, the seventh ball valve, the thirteenth ball valve, the nineteenth ball valve, the twentieth ball valve, the fourteenth ball valve, the sixteenth ball valve, the eighteenth ball valve, and the fifth ball valve; Step 7.2, open the first outlet ball valve, close the connecting ball valve and the second outlet ball valve, start the first pump group, and adjust the first proportional relief valve to set the test pressure; Step 7.3, open the third outlet ball valve, the fourth ball valve, and the sixth ball valve, start the third pump group, adjust the second proportional relief valve and the pressure reducing valve to set the pilot control oil pressure, and adjust the third proportional throttle valve to set the test flow; Step 7.4, closing the first proportional throttle valve and the second proportional throttle valve; Step 7.5, input a signal to the valve to be tested so that the output flow is 25% of the rated flow, then gradually reduce the input signal so that the flow also decreases accordingly, and slowly reduce the input signal to minimize the dynamic impact; Step 7.6, record the input signal when the flow rate starts to decrease; Step 7.7, calculate the threshold value by calculating the signal change increment according to the algebraic difference of the two recorded signal values, and draw a curve with the given signal percentage as the X-axis and the flow signal as the Y-axis; Step 7.8, repeat the test steps of steps 7.4 to 7.6 at 75% of the rated flow rate; Step 7.9, input the opposite signal and repeat the test steps of step 7.4 to step 7.7; Step 7.10, when testing the zero position of the zero opening and negative cover valve, use this threshold characteristic test method; Throttling regulation characteristics test: When from the oil supply port P to the working oil port A: Step 8.1.1, open the second ball valve, the seventh ball valve, the twelfth ball valve, the sixteenth ball valve, the eighteenth ball valve, and the fifth ball valve; Step 8.1.2, open the first outlet ball valve, close the connecting ball valve and the second outlet ball valve, start the first pump group, and adjust the first proportional relief valve to set the test pressure; Step 8.1.3, open the third outlet ball valve, the fourth ball valve, and the sixth ball valve, start the third pump group, adjust the second proportional relief valve and the pressure reducing valve to set the pilot control oil pressure, and adjust the third proportional throttle valve to set the test flow; Step 8.1.4, slowly increase the input signal from zero to the rated positive value, and draw the flow curve from the oil supply port P to the working oil port A with the given signal as the X-axis and the flow signal as the Y-axis.

[0018] From the working oil port A to the return oil port T: Step 8.2.1, open the second ball valve, the seventeenth ball valve, the sixteenth ball valve, the twelfth ball valve, the twenty-first ball valve, and the fifth ball valve; Step 8.2.2, open the first outlet ball valve, close the connecting ball valve and the second outlet ball valve, start the first pump group, and adjust the first proportional relief valve to set the test pressure; Step 8.2.3, open the third outlet ball valve, the fourth ball valve, and the sixth ball valve, start the third pump group, adjust the second proportional relief valve and the pressure reducing valve to set the pilot control oil pressure, and adjust the third proportional throttle valve to set the test flow; Step 8.2.4, slowly increase the input signal from zero to the rated positive value, and draw a flow curve from the working oil port A to the return oil port T with the given signal as the X-axis and the flow signal as the Y-axis; From the oil supply port P to the working oil port B: Step 8.3.1, open the second ball valve, the seventh ball valve, the eleventh ball valve, the sixteenth ball valve, the eighteenth ball valve, and the fifth ball valve; Step 8.3.2, open the first outlet ball valve, close the connecting ball valve and the second outlet ball valve, start the first pump group, and adjust the first proportional relief valve to set the test pressure; Step 8.3.3, open the third outlet ball valve, the fourth ball valve, and the sixth ball valve, start the third pump group, adjust the second proportional relief valve and the pressure reducing valve to set the pilot control oil pressure, and adjust the third proportional throttle valve to set the test flow; Step 8.3.4, slowly increase the input signal from zero to the rated positive value, and draw the flow curve from the oil supply port P to the working oil port B with the given signal as the X-axis and the flow signal as the Y-axis.

[0019] From working oil port B to return oil port T: Step 8.4.1, open the second ball valve, the seventeenth ball valve, the sixteenth ball valve, the eleventh ball valve, the twenty-first ball valve, and the fifth ball valve; Step 8.4.2, open the first outlet ball valve, close the connecting ball valve and the second outlet ball valve, start the first pump group, and adjust the first proportional relief valve to set the test pressure; Step 8.4.3, open the third outlet ball valve, the fourth ball valve, and the sixth ball valve, start the third pump group, adjust the second proportional relief valve and the pressure reducing valve to set the pilot control oil pressure, and adjust the third proportional throttle valve to set the test flow; Step 8.4.4, slowly increase the input signal from zero to the rated positive value, and draw the flow curve from the working oil port B to the return oil port T with the given signal as the X-axis and the flow signal as the Y-axis.

[0020] The present invention has the following beneficial effects: 1. The test system of the present invention can test different functions of different valves, including internal leakage test and steady-state pressure difference-flow characteristic test of electromagnetic reversing valve and electromagnetic ball valve; internal leakage test, output flow-input signal characteristic test, threshold characteristic test, throttling regulation characteristic test, output flow-load pressure difference characteristic test, output flow-valve pressure drop characteristic test, limit power characteristic test, pressure zero drift, fault protection function test, dynamic test and other parameters of servo valve and proportional valve. The test of different valves can be realized on a test platform, which is helpful to understand whether the performance of old valves and newly purchased valves meet the on-site requirements and quality evaluation, and greatly assists the maintenance and repair of hydraulic equipment.

[0021] 2. The above oil tank system can be used to provide hydraulic oil during the test.

[0022] 3. The cooling circulation device can be used to circulate and cool the hydraulic oil during the test, thereby ensuring the performance of the hydraulic oil.

[0023] 4. The above-mentioned cooler can ensure the best cooling effect.

[0024] 5. The first main pump-motor system can be used to provide the required hydraulic power during the test.

[0025] 6. Through the above system, when the oil supply flow of the first main pump motor group system does not meet the oil demand of the first test system, the second outlet ball valve of the second main pump motor group system can be closed, and the connecting ball valve 61.2 can be opened to start the first main pump motor group system and the second main pump motor group system to supply oil to the first test system. Similarly, when the oil supply flow of the second main pump motor group system does not meet the oil demand of the second test system, the first outlet ball valve of the first pump group can be closed, and the connecting ball valve 61.2 can be opened to start the first main pump motor group system and the second main pump motor group system to supply oil to system P2.

[0026] 7. Through the above system, when the first main pump motor system fails, the second outlet ball valve of the second main pump motor system can be closed, the connecting ball valve can be opened, and then the second main pump motor system can be started to supply oil to the first test system. Similarly, when the second main pump motor system fails, the first outlet ball valve of the first main pump motor system can be closed, the connecting ball valve can be opened, and then the first main pump motor system can be started to supply oil to the second test system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0028] Figure 1 This is the hydraulic pump station system of the present invention.

[0029] Figure 2 This is the control valve test bench system of the present invention.

[0030] In the figure: first test system P1, second test system P2, third test system P3; Main oil tank 43, drain ball valve 42, heater 28, liquid level sensor 25, visual level gauge 23, temperature sensor 27, return oil filter 92, oil filling filter 30, oil sampling ball valve 91; A ball valve with switch signal 90, a first flexible joint 89, a cooling pump motor unit 07.2, a first non-return valve 66, a cooler 29, a first ball valve 96, and a filter 32; Inlet ball valve 71.1, electromagnetic water valve 72, outlet ball valve 71.2; The first oil suction ball valve 21.1, the second flexible joint 19.1, the first pump group 01.1, the first high-pressure filter 33.1, the second non-return valve 69.1, the first outlet ball valve 61.1, the first test system P1, the first seismic pressure gauge 47.1, the first electromagnetic relief valve 87.1, the first proportional relief valve 75, the first pressure sensor 50.1, the connecting ball valve 61.2, and the second test system P2; The second oil suction ball valve 21.2, the third flexible joint 19.2, the second pump group 01.2, the second high-pressure filter 33.2, the third one-way valve 69.2, the second outlet ball valve 61.3, the second seismic-resistant pressure gauge 47.2, the second electromagnetic overflow valve 87.2, and the second pressure sensor 50.2; The third oil suction ball valve 22.1, the fourth flexible joint 20.1, the third pump group 02, the third high-pressure filter 34, the fourth non-return valve 70.1, the third outlet ball valve 62.1, the third seismic pressure gauge 47.3, the third electromagnetic relief valve 87.3, the second proportional relief valve 76, and the third pressure sensor 50.3; A first accumulator 37, a second accumulator 38, a first safety shut-off valve group 39, and a second safety shut-off valve group 40; The second ball valve 60.9, the third ball valve 60.10, the fourth ball valve 63.1, the fifth ball valve 59.1, the sixth ball valve 63.4, the seventh ball valve 60.11, the eighth ball valve 53, the ninth ball valve 54, the tenth ball valve 59.2, the eleventh ball valve 60.7, the twelfth ball valve 60.6, the thirteenth ball valve 60.4, the fourteenth ball valve 41.2, the fifteenth ball valve 59.3, the sixteenth ball valve 60.8, the seventeenth ball valve 60.2, the eighteenth ball valve 60.3, the nineteenth ball valve 60.1, the twentieth ball valve 60.5, the twenty-first ball valve 41.1, the twenty-second ball valve 51, and the twenty-third ball valve 52; A first flow meter 73, a second flow meter 74, and a pressure reducing valve 77; A first proportional throttle valve 78.1, a second proportional throttle valve 78.2, and a third proportional throttle valve 78.3; A first electromagnetic reversing valve 79.1 and a second electromagnetic reversing valve 79.2. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Embodiment 1: like Figure 1-2As shown, a hydraulic directional valve test system includes a hydraulic pump station system for providing hydraulic power during the test; the hydraulic pump station system includes an oil tank system, and the oil tank system is connected in parallel with a first main pump motor group system and a second main pump motor group system, the first main pump motor group system is used to provide hydraulic power for a first test system P1, and the second main pump motor group system is used to provide hydraulic power for a second test system P2; a control pump motor group system is connected to the oil tank system, and the control pump motor group system is used to provide hydraulic power for a third test system P3; the first test system P1, the second test system P2 and the third test system P3 are connected to a control valve test bench system for testing the valve to be tested. By adopting the above-mentioned hydraulic directional valve test system, different functions of different valves can be tested, including internal leakage test and steady-state pressure difference-flow characteristic test of solenoid reversing valve and solenoid ball valve; internal leakage test, output flow-input signal characteristic test, threshold characteristic test, throttling adjustment characteristic test, output flow-load pressure difference characteristic test, output flow-valve pressure drop characteristic test, limit power characteristic test, pressure zero drift, fault protection function test, dynamic test and other parameters of servo valve and proportional valve. Different valves can be tested on a test platform, which is helpful to understand whether the performance of old valves and newly purchased valves meet on-site requirements and quality evaluation, and greatly assists the maintenance and repair of hydraulic equipment.

[0033] Furthermore, the entire hydraulic pump station system is arranged inside the valve station pump station room; the oil tank system includes a main oil tank 43, on which a plurality of drain ball valves 42 are arranged, a plurality of sets of heaters 28 are arranged inside the main oil tank 43, and a liquid level sensor 25, a visual liquid level gauge 23, a temperature sensor 27, a return oil filter 92, an oil injection filter 30 and an oil sampling ball valve 91 are also installed on the main oil tank 43. The above-mentioned oil tank system can be used to provide hydraulic oil during the test process.

[0034] Furthermore, the main oil tank 43 is connected with a cooling circulation device for cooling the oil, and the cooling circulation device includes a switch signaling ball valve 90 connected to the main oil tank 43, the switch signaling ball valve 90 is connected to the cooling pump motor unit 07.2 through the first flexible joint 89, the outlet of the cooling pump motor unit 07.2 is connected to the cooler 29 through the first check valve 66, the outlet of the cooler 29 is connected in parallel with the first ball valve 96, and the first ball valve 96 is connected to the main oil tank 43 through the filter 32. The above-mentioned cooling circulation device can be used to circulate and cool the hydraulic oil during the test, thereby ensuring the performance of the hydraulic oil. In the specific working process, the working principle of the cooling circulation device is: start the cooling pump motor unit 07.2, and the oil enters the cooler through the switch signaling ball valve 90, the first flexible joint 89, and the first check valve 66, wherein the water inlet ball valve 71.1 is connected to the cooling water inlet, and the water outlet ball valve 71.2 is connected to the cooling water outlet. The oil and cooling water complete heat exchange in the cooler, and finally, the oil flows back to the oil tank through the first ball valve 96 and the filter 32.

[0035] Furthermore, the cooler 29 is a plate cooler, and a water inlet ball valve 71.1 for cooling water to enter is connected to the cooler 29, an electromagnetic water valve 72 is installed on the pipeline after the water inlet ball valve 71.1, and a water outlet ball valve 71.2 is connected to the cooling water outlet of the cooler 29. The above-mentioned cooler 29 can ensure the best cooling effect.

[0036] Furthermore, the first main pump motor group system includes a first oil suction ball valve 21.1 connected to the main oil tank 43, the first oil suction ball valve 21.1 is connected to the first pump group 01.1 through the second flexible joint 19.1, the oil outlet of the first pump group 01.1 is connected to the first high-pressure filter 33.1, and the first high-pressure filter 33.1 is connected to the first test system P1 through the second one-way valve 69.1 and the first outlet ball valve 61.1 in turn; the first shock-resistant pressure gauge 47.1 and the first electromagnetic overflow valve 87.1 are installed on the pipeline between the first high-pressure filter 33.1 and the second one-way valve 69.1; the first proportional overflow valve 75, the first pressure sensor 50.1 and the connecting ball valve 61.2 are installed on the pipeline between the second one-way valve 69.1 and the first outlet ball valve 61.1, and the other end of the connecting ball valve 61.2 is connected to the second test system P2. The above-mentioned first main pump motor group system can be used to provide the required hydraulic power during the test process.

[0037] Furthermore, the second main pump motor group system includes a second oil suction ball valve 21.2 connected to the main oil tank 43, the second oil suction ball valve 21.2 is connected to the second pump group 01.2 through the third flexible joint 19.2, the oil outlet of the second pump group 01.2 is connected to the second high-pressure filter 33.2, and the second high-pressure filter 33.2 is connected to the second test system P2 through the third one-way valve 69.2 and the second outlet ball valve 61.3 in turn; the second shock-resistant pressure gauge 47.2 and the second electromagnetic overflow valve 87.2 are installed on the pipeline between the second high-pressure filter 33.2 and the third one-way valve 69.2; the pipeline between the third one-way valve 69.2 and the second outlet ball valve 61.3 is connected to the ball valve 61.2 and is installed with a second pressure sensor 50.2. The above-mentioned second main pump motor group system can be used to provide the required hydraulic power during the test process and be a backup for the first main pump motor group system.

[0038] Among them, the first main pump motor system and the second main pump motor system have the same operating principle. Take the control principle of the first main pump motor system as an example: start the pump motor, the pressure oil enters the first pump group 01.1 through the first oil suction ball valve 21.1 and the second flexible joint 19.1, and the oil pump pressure oil passes through the first high-pressure filter 33.1, the second one-way valve 69.1, and the first outlet ball valve 61.1 to supply oil to the system. Among them, the first electromagnetic overflow valve 87.1 is the safety pressure of the oil pump to ensure that the oil pump will not be overloaded; the first high-pressure filter 33.1 is mainly to ensure the cleanliness of the oil when the system is working, to prevent impurities from entering the system circuit, causing valve jamming and other phenomena; the first proportional overflow valve 75 adjusts the system pressure steplessly through the electronic control system; the first seismic pressure gauge 47.1 displays the system pressure; the first pressure sensor 50.1 and the second pressure sensor 50.2 monitor the pressure of the first main pump motor system and the second main pump motor system in real time.

[0039] When the oil supply flow of the first main pump motor group system does not meet the oil demand of the first test system P1, the second outlet ball valve 61.3 of the second main pump motor group system can be closed, and the connecting ball valve 61.2 can be opened to start the first main pump motor group system and the second main pump motor group system to supply oil to the first test system P1. Similarly, when the oil supply flow of the second main pump motor group system does not meet the oil demand of the second test system P2, the first outlet ball valve 61.1 of the first pump group 01.1 can be closed, and the connecting ball valve 61.2 can be opened to start the first main pump motor group system and the second main pump motor group system to supply oil to the system P2.

[0040] When the first main pump motor system fails, the second outlet ball valve 61.3 of the second main pump motor system can be closed, the connecting ball valve 61.2 can be opened, and then the second main pump motor system can be started to supply oil to the first test system P1. Similarly, when the second main pump motor system fails, the first outlet ball valve 61.1 of the first main pump motor system can be closed, the connecting ball valve 61.2 can be opened, and then the first main pump motor system can be started to supply oil to the second test system P2.

[0041] Furthermore, the control pump motor group system includes a third oil suction ball valve 22.1 connected to the main oil tank 43, the third oil suction ball valve 22.1 is connected to the third pump group 02 through the fourth flexible joint 20.1, the oil outlet of the third pump group 02 is connected to the third high-pressure filter 34, and the third high-pressure filter 34 is connected to the third test system P3 through the fourth check valve 70.1 and the third outlet ball valve 62.1 in turn; the third seismic pressure gauge 47.3 and the third electromagnetic overflow valve 87.3 are installed on the pipeline between the third pump group 02 and the third high-pressure filter 34; the second proportional overflow valve 76 and the third pressure sensor 50.3 are installed on the pipeline between the fourth check valve 70.1 and the third outlet ball valve 62.1. The control principle of the control pump motor group system is consistent with the "first main pump motor group system control principle".

[0042] Furthermore, the first pump group 01.1 adopts a constant pressure variable piston pump and is connected to the first drive motor 06.1 to provide oil pumping power; thereby facilitating the realization of different oil supply flow rates and pressures.

[0043] Furthermore, the second pump group 01.2 adopts a constant pressure variable piston pump and is connected to the second drive motor 06.2 to provide oil pumping power; thereby facilitating the realization of different oil supply flow rates and pressures.

[0044] Furthermore, the third pump group 02 adopts a constant pressure variable displacement pump and is connected to the third drive motor 07.1 to provide pumping oil power.

[0045] Furthermore, the control valve test bench system is arranged in a valve test laboratory, and the valve test laboratory is connected to the valve platform pump station room through a hydraulic pipeline; The control valve test bench system includes a second ball valve 60.9 connected to the P1 port of the first test system, and the pipeline after the second ball valve 60.9 is connected to the P oil port of the valve to be tested through the seventh ball valve 60.11; It also includes a third ball valve 60.10 connected to the P2 port of the second test system, and the pipeline after the third ball valve 60.10 is connected to the P oil port of the valve to be tested through a seventh ball valve 60.11; It also includes a fourth ball valve 63.1 connected to the P3 port of the third test system, and the fourth ball valve 63.1 is connected to the X oil port of the valve to be tested through the pressure reducing valve 77 and the sixth ball valve 63.4; The pipeline between the third ball valve 60.10 and the seventh ball valve 60.11 is connected with a bypass flow regulating component and a seventeenth ball valve 60.2. The pipeline after the seventeenth ball valve 60.2 is connected to the B oil port of the valve to be tested through the second flow meter 74, the fifteenth ball valve 59.3 and the eleventh ball valve 60.7 in sequence. The B oil port of the valve to be tested is connected to a cavity of the dynamic measuring cylinder 80 through the eighth ball valve 53. The A oil port of the valve to be tested is connected to the thirteenth ball valve 60.4, the twelfth ball valve 60.6 and the ninth ball valve 54 at the same time; the thirteenth ball valve 60.4 is connected to the B oil port of the valve to be tested through the throttling loading assembly and the twentieth ball valve 60.5; the twelfth ball valve 60.6 is connected to the return oil pipeline through the sixteenth ball valve 60.8, the first flow meter 73 and the eighteenth ball valve 60.3 in sequence; the ninth ball valve 54 is connected to another cavity of the dynamic measuring cylinder 80; The T oil port of the valve to be tested is connected to the twenty-first ball valve 41.1 and the fourteenth ball valve 41.2 at the same time, and the twenty-first ball valve 41.1 is connected to the oil return pipeline; the fourteenth ball valve 41.2 is connected to the Y oil port of the valve to be tested through the tenth ball valve 59.2, and is connected to the main oil tank 43 of the control pump motor system through the fifth ball valve 59.1; The pipeline after the fourth ball valve 63.1 is connected to the first accumulator 37 through the first safety shut-off valve group 39, and the first safety shut-off valve group 39 is also connected to the oil return pipeline; The T oil port of the valve to be tested is connected to the second accumulator 38 through the twenty-third ball valve 52 and the second safety shut-off valve group 40 , and the second safety shut-off valve group 40 is connected to the P oil port of the valve to be tested through the twenty-second ball valve 51 .

[0046] Furthermore, the bypass flow regulating component includes a third proportional throttle valve 78.3 and an electromagnetic reversing valve 79.2 connected in parallel, and the other ports of the third proportional throttle valve 78.3 and the electromagnetic reversing valve 79.2 are connected to the return oil pipeline.

[0047] Furthermore, the throttling loading assembly includes a first proportional throttle valve 78.1, a second proportional throttle valve 78.2, a first electromagnetic reversing valve 79.1 and a nineteenth ball valve 60.1 connected in parallel.

[0048] Furthermore, the control valve test bench operation room is equipped with a control valve station, a weak current control box, a rocker arm operation box, an operating ball valve, a display instrument, a dynamic measuring cylinder, an accumulator, an oil collection pump unit, an industrial computer and other components.

[0049] Embodiment 2: A method for testing the performance of a valve to be tested using a hydraulic directional valve test system as described in claim 11, characterized in that it includes testing of electromagnetic reversing valves and electromagnetic ball valves: Internal leakage test, the oil flows from the P port to the T port of the valve to be tested: Step 1.1, open the second ball valve 60.9, the seventh ball valve 60.11, the fourteenth ball valve 41.2, the fifteenth ball valve 59.3 and the eighteenth ball valve 60.3; Step 1.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, adjust the first proportional relief valve 75 to set the test pressure, and adjust the third proportional throttle valve 78.3 to set the test flow; Step 1.3, the test valve is powered on or off to close the oil port from P to T, and the internal leakage is detected by the second flow meter 74; Internal leakage test, the oil flows from the P port to the A port of the valve to be tested: Step 2.1, open the second ball valve 60.9, the seventh ball valve 60.11, the twelfth ball valve 60.6, the fifteenth ball valve 59.3, and the eighteenth ball valve 60.3; Step 2.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, adjust the first proportional relief valve 75 to set the test pressure, and adjust the third proportional throttle valve 78.3 to set the test flow; Step 2.3, the test valve is powered on or off to close the oil port P to the oil port A, and the internal leakage is detected by the second flow meter 74; Internal leakage test, the oil flows from the P port to the B port of the valve to be tested: Step 3.1, open the second ball valve 60.9, the seventh ball valve 60.11, the eleventh ball valve 60.7, the fifteenth ball valve 59.3, and the eighteenth ball valve 60.3; Step 3.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, adjust the first proportional relief valve 75 to set the test pressure, and adjust the third proportional throttle valve 78.3 to set the test flow; Step 3.3, the test valve is powered on or off to close the oil port from P to B, and the internal leakage is detected by the second flow meter 74; Steady-state pressure difference-flow characteristic test: Step 4.1, open the second ball valve 60.9, the seventh ball valve 60.11, the thirteenth ball valve 60.4, the twentieth ball valve 60.5, the nineteenth ball valve 60.1, the fourteenth ball valve 41.2, the sixteenth ball valve 60.8, and the eighteenth ball valve 60.3; If it is a three-way valve, open the second ball valve 60.9, the seventh ball valve 60.11, the thirteenth ball valve 60.4, the twentieth ball valve 60.5, the eleventh ball valve 60.7, the sixteenth ball valve 60.8, and the eighteenth ball valve 60.3; Step 4.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, adjust the first proportional relief valve 75 to set the test pressure, and adjust the third proportional throttle valve 78.3 to fully open the valve port for diversion; Step 4.3, close the first proportional throttle valve 78.1 and the second proportional throttle valve 78.2; Step 4.4, the valve to be tested is powered on or off to make the valve port connected, and a signal is input to the third proportional throttle valve 78.3 to gradually reduce the diversion flow, and the flow of the valve to be tested is gradually increased from zero. The pressure difference-flow characteristic curve is plotted with the output flow as the X-axis and the pressure difference as the Y-axis.

[0050] Embodiment 3: A method for testing the performance of a valve to be tested using a hydraulic directional valve test system, including servo valve and proportional valve tests: Internal leakage test: Step 5.1, open the second ball valve 60.9, the seventh ball valve 60.11, the fourteenth ball valve 41.2, the fifteenth ball valve 59.3, and the eighteenth ball valve 60.3; Step 5.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, and adjust the first proportional relief valve 75 to set the test pressure; Step 5.3, open the connecting ball valve 61.2, the fourth ball valve 63.1, and the sixth ball valve 63.4, start the third pump group 02, adjust the second proportional relief valve 76 and the pressure reducing valve 77 to set the pilot control oil pressure, and adjust the third proportional throttle valve 78.3 to set the test flow; Step 5.4, input a periodic signal to the valve to be tested, detect the leakage of the T oil port through the second flow meter 74, open the tenth ball valve 59.2 and the twenty-first ball valve 41.1, close the fifth ball valve 59.1 and the fourteenth ball valve 41.2, and detect the leakage of the Y oil port through the second flow meter 74; Output flow-input signal characteristic test under constant valve pressure drop: Step 6.1, open the second ball valve 60.9, the seventh ball valve 60.11, the thirteenth ball valve 60.4, the nineteenth ball valve 60.1, the twentieth ball valve 60.5, the fourteenth ball valve 41.2, the sixteenth ball valve 60.8, the eighteenth ball valve 60.3, and the fifth ball valve 59.1; Step 6.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, and adjust the first proportional relief valve 75 to set the test pressure; Step 6.3, open the third outlet ball valve 62.1, the fourth ball valve 63.1, and the sixth ball valve 63.4, start the third pump group 02, adjust the second proportional relief valve 76 and the pressure reducing valve 77 to set the pilot control oil pressure, and adjust the third proportional throttle valve 78.3 to set the test flow; Step 6.4, close the first proportional throttle valve 78.1 and the second proportional throttle valve 78.2; Step 6.5, input a periodic signal to the valve to be tested, and draw its output flow-input signal characteristic curve with the given signal percentage as the X-axis and the flow signal as the Y-axis; Threshold characteristic test: Step 7.1, open the second ball valve 60.9, the seventh ball valve 60.11, the thirteenth ball valve 60.4, the nineteenth ball valve 60.1, the twentieth ball valve 60.5, the fourteenth ball valve 41.2, the sixteenth ball valve 60.8, the eighteenth ball valve 60.3, and the fifth ball valve 59.1; Step 7.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, and adjust the first proportional relief valve 75 to set the test pressure; Step 7.3, open the third outlet ball valve 62.1, the fourth ball valve 63.1, and the sixth ball valve 63.4, start the third pump group 02, adjust the second proportional relief valve 76 and the pressure reducing valve 77 to set the pilot control oil pressure, and adjust the third proportional throttle valve 78.3 to set the test flow; Step 7.4, closing the first proportional throttle valve 78.1 and the second proportional throttle valve 78.2; Step 7.5, input a signal to the valve to be tested so that the output flow is 25% of the rated flow, then gradually reduce the input signal so that the flow also decreases accordingly, and slowly reduce the input signal to minimize the dynamic impact; Step 7.6, record the input signal when the flow rate starts to decrease; Step 7.7, calculate the threshold value by calculating the signal change increment according to the algebraic difference of the two recorded signal values, and draw a curve with the given signal percentage as the X-axis and the flow signal as the Y-axis; Step 7.8, repeat the test steps of steps 7.4 to 7.6 at 75% of the rated flow rate; Step 7.9, input the opposite signal and repeat the test steps of step 7.4 to step 7.7; Step 7.10, when testing the zero position of the zero opening and negative cover valve, use this threshold characteristic test method; Throttling regulation characteristics test: When from the oil supply port P to the working oil port A: Step 8.1.1, open the second ball valve 60.9, the seventh ball valve 60.11, the twelfth ball valve 60.6, the sixteenth ball valve 60.8, the eighteenth ball valve 60.3, and the fifth ball valve 59.1; Step 8.1.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, and adjust the first proportional relief valve 75 to set the test pressure; Step 8.1.3, open the third outlet ball valve 62.1, the fourth ball valve 63.1, and the sixth ball valve 63.4, start the third pump group 02, adjust the second proportional relief valve 76 and the pressure reducing valve 77 to set the pilot control oil pressure, and adjust the third proportional throttle valve 78.3 to set the test flow; Step 8.1.4, slowly increase the input signal from zero to the rated positive value, and draw the flow curve from the oil supply port P to the working oil port A with the given signal as the X-axis and the flow signal as the Y-axis.

[0051] From the working oil port A to the return oil port T: Step 8.2.1, open the second ball valve 60.9, the seventeenth ball valve 60.2, the sixteenth ball valve 60.8, the twelfth ball valve 60.6, the twenty-first ball valve 41.1, and the fifth ball valve 59.1; Step 8.2.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, and adjust the first proportional relief valve 75 to set the test pressure; Step 8.2.3, open the third outlet ball valve 62.1, the fourth ball valve 63.1, and the sixth ball valve 63.4, start the third pump group 02, adjust the second proportional relief valve 76 and the pressure reducing valve 77 to set the pilot control oil pressure, and adjust the third proportional throttle valve 78.3 to set the test flow; Step 8.2.4, slowly increase the input signal from zero to the rated positive value, and draw a flow curve from the working oil port A to the return oil port T with the given signal as the X-axis and the flow signal as the Y-axis; From the oil supply port P to the working oil port B: Step 8.3.1, open the second ball valve 60.9, the seventh ball valve 60.11, the eleventh ball valve 60.7, the sixteenth ball valve 60.8, the eighteenth ball valve 60.3, and the fifth ball valve 59.1; Step 8.3.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, and adjust the first proportional relief valve 75 to set the test pressure; Step 8.3.3, open the third outlet ball valve 62.1, the fourth ball valve 63.1, and the sixth ball valve 63.4, start the third pump group 02, adjust the second proportional relief valve 76 and the pressure reducing valve 77 to set the pilot control oil pressure, and adjust the third proportional throttle valve 78.3 to set the test flow; Step 8.3.4, slowly increase the input signal from zero to the rated positive value, and draw the flow curve from the oil supply port P to the working oil port B with the given signal as the X-axis and the flow signal as the Y-axis.

[0052] From working oil port B to return oil port T: Step 8.4.1, open the second ball valve 60.9, the seventeenth ball valve 60.2, the sixteenth ball valve 60.8, the eleventh ball valve 60.7, the twenty-first ball valve 41.1, and the fifth ball valve 59.1; Step 8.4.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, and adjust the first proportional relief valve 75 to set the test pressure; Step 8.4.3, open the third outlet ball valve 62.1, the fourth ball valve 63.1, and the sixth ball valve 63.4, start the third pump group 02, adjust the second proportional relief valve 76 and the pressure reducing valve 77 to set the pilot control oil pressure, and adjust the third proportional throttle valve 78.3 to set the test flow; Step 8.4.4, slowly increase the input signal from zero to the rated positive value, and draw the flow curve from the working oil port B to the return oil port T with the given signal as the X-axis and the flow signal as the Y-axis.

[0053] Output flow-load pressure difference characteristic test: Step 9.1, open the second ball valve 60.9, the seventh ball valve 60.11, the thirteenth ball valve 60.4, the twentieth ball valve 60.5, the fourteenth ball valve 41.2, the sixteenth ball valve 60.8, the eighteenth ball valve 60.3, and the fifth ball valve 59.1; Step 9.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, and adjust the first proportional relief valve 75 to set the test pressure; Step 9.3, open the third outlet ball valve 62.1, the fourth ball valve 63.1, and the sixth ball valve 63.4, start the third pump group 02, adjust the second proportional relief valve 76 and the pressure reducing valve 77 to set the pilot control oil pressure, and adjust the third proportional throttle valve 78.3 to set the test flow; Step 9.4, opening the first proportional throttle valve 78.1 and the second proportional throttle valve 78.2; Step 9.5, make the input given signal change between the maximum positive value and the maximum negative value step by step for several cycles; Step 9.6, when inputting different constant values: ±25%, ±50%, ±75%, ±100%, to the valve to be tested, input signals to the first proportional throttle valve 78.1 simultaneously to close the valve port slowly, and draw its output flow-load pressure difference characteristic curve with load pressure difference pA-pB as X-axis and output flow as Y-axis.

[0054] Output flow-valve pressure drop characteristic test: Step 10.1, open the second ball valve 60.9, the seventh ball valve 60.11, the thirteenth ball valve 60.4, the twentieth ball valve 60.5, the fourteenth ball valve 41.2, the sixteenth ball valve 60.8, the eighteenth ball valve 60.3, and the fifth ball valve 59.1; Step 10.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, and adjust the first proportional relief valve 75 to set the test pressure; Step 10.3, open the third outlet ball valve 62.1, the fourth ball valve 63.1, and the sixth ball valve 63.4, start the third pump group 02, adjust the second proportional relief valve 76 and the pressure reducing valve 77 to set the pilot control oil pressure, and adjust the third proportional throttle valve 78.3 to set the test flow; Step 10.4, closing the first proportional throttle valve 78.1 and the second proportional throttle valve 78.2; Step 10.5, making the input given signal change between the maximum positive value and the maximum negative value step by step and cycle for several times; Step 10.6, when inputting different constant values: ±25%, ±50%, ±75%, ±100%, to the valve to be tested, input signals to the first proportional throttle valve 78.1 simultaneously to slowly open the valve port, and draw its output flow-valve pressure drop characteristic curve with pressure drop: pP-pL-pT, pL=|pA-pB| as X-axis and output flow as Y-axis.

[0055] Limit power characteristic test: Step 11.1, open the second ball valve 60.9, the seventh ball valve 60.11, the thirteenth ball valve 60.4, the nineteenth ball valve 60.1, the twentieth ball valve 60.5, the fourteenth ball valve 41.2, the sixteenth ball valve 60.8, the eighteenth ball valve 60.3, and the fifth ball valve 59.1; Step 11.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, and adjust the first proportional relief valve 75 to set the test pressure; Step 11.3, open the third outlet ball valve 62.1, the fourth ball valve 63.1, and the sixth ball valve 63.4, start the third pump group 02, adjust the second proportional relief valve 76 and the pressure reducing valve 77 to set the pilot control oil pressure, and adjust the third proportional throttle valve 78.3 to set the test flow; Step 11.4, close the first proportional throttle valve 78.1 and the second proportional throttle valve 78.2; Step 11.5, adjust the input given signal to 95% of the maximum positive value, and then superimpose a low-frequency small sine signal ±5%, with a typical frequency of 0.2Hz to 0.4Hz; Step 11.6, when inputting different constant values: ±25%, ±50%, ±75%, ±100%, to the valve to be tested, slowly increase the oil supply pressure of the valve at the same time, and draw its output flow-valve pressure drop characteristic curve with pressure drop: pP-pL-pT, pL=|pA-pB| as the X-axis and output flow as the Y-axis.

[0056] Step 11.7, when the sinusoidal motion stops or the flow rate suddenly decreases, stop increasing the oil supply pressure, mark this point on the graph, and connect those marked points, that is, the zero slope points on the curve, to obtain the limiting power characteristic curve.

[0057] Pressure gain-input signal characteristic test: Step 12.1, open the second ball valve 60.9, the seventh ball valve 60.11, the twenty-first ball valve 41.1, and the fifth ball valve 59.1; Step 12.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, and adjust the first proportional relief valve 75 to set the test pressure; Step 12.3, open the third outlet ball valve 62.1, the fourth ball valve 63.1, and the sixth ball valve 63.4, start the third pump group 02, adjust the second proportional relief valve 76 and the pressure reducing valve 77 to set the pilot control oil pressure, and adjust the third proportional throttle valve 78.3 to set the test flow; Step 12.4, input the periodic signal to the valve to be tested, and ensure that the period is set longer so that the input signal changes slowly. Use the given signal percentage as the X-axis, and the pressure of ports A and B: pA, pB and the pressure difference: pA-pB as the Y-axis to draw the pressure gain-input signal characteristic.

[0058] Pressure zero drift: Step 13.1, open the second ball valve 60.9, the seventh ball valve 60.11, the twenty-first ball valve 41.1, and the fifth ball valve 59.1; Step 13.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, and adjust the first proportional relief valve 75 to set the test pressure; Step 13.3, open the third outlet ball valve 62.1, the fourth ball valve 63.1, and the sixth ball valve 63.4, start the third pump group 02, adjust the second proportional relief valve 76 and the pressure reducing valve 77 to set the pilot control oil pressure, and adjust the third proportional throttle valve 78.3 to set the test flow; Step 13.4, when the system oil supply pressure is 10MPa, adjust the input signal to make the pressures of ports A and B equal, and record the input signal value at this time; Step 13.5, set the oil supply pressure to 5MPa and 20MPa respectively, adjust the input signal to make the pressure of oil port A and B equal, record the input signal value at this time, and determine the pressure zero drift of the valve by the recorded given signal value.

[0059] Fault protection function test: Step 14.1, as required, set the oil circuit to a test oil circuit with flow characteristics or pressure characteristics; Step 14.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, and adjust the first proportional relief valve 75 to set the test pressure; Step 14.3, open the third outlet ball valve 62.1, the fourth ball valve 63.1, and the sixth ball valve 63.4, start the third pump group 02, adjust the second proportional relief valve 76 and the pressure reducing valve 77 to set the pilot control oil pressure, and adjust the third proportional throttle valve 78.3 to set the test flow; Step 14.4, simulate various fault conditions and determine the fault protection function of the valve to be tested by detecting the valve core displacement signal.

[0060] Embodiment 4: This embodiment provides a dynamic test, which specifically includes: Frequency characteristics: Servo valves and proportional directional valves with electrical feedback: Step 15.1.1, open the second ball valve 60.9, the seventh ball valve 60.11, the thirteenth ball valve 60.4, the nineteenth ball valve 60.1, the twentieth ball valve 60.5, the fourteenth ball valve 41.2, the sixteenth ball valve 60.8, the eighteenth ball valve 60.3, and the fifth ball valve 59.1; Step 15.1.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, and adjust the first proportional relief valve 75 to set the test pressure; Step 15.1.3, open the third outlet ball valve 62.1, the fourth ball valve 63.1, and the sixth ball valve 63.4, start the third pump group 02, adjust the second proportional relief valve 76 and the pressure reducing valve 77 to set the pilot control oil pressure, and adjust the third proportional throttle valve 78.3 to set the test flow; Step 15.1.4, close the first proportional throttle valve 78.1 and the second proportional throttle valve 78.2; Step 15.1.5, opening the first safety shut-off valve group 39 of the first accumulator 37; Step 15.1.6, within the rated signal range, input a frequency sweep signal to the valve to be tested, draw a Bode diagram through the displacement feedback signal of the valve to be tested, and thus measure its frequency characteristics; Servo valve without electrical feedback, i.e. mechanical feedback: Step 15.2.1, open the second ball valve 60.9, the seventh ball valve 60.11, the twenty-first ball valve 41.1, the twenty-second ball valve 51, the twenty-third ball valve 52, the eighth ball valve 53, and the ninth ball valve 54; Step 15.2.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, and adjust the first proportional relief valve 75 to set the test pressure; Step 15.2.3, open the third outlet ball valve 62.1, the fourth ball valve 63.1, and the sixth ball valve 63.4, start the third pump group 02, adjust the second proportional relief valve 76 and the pressure reducing valve 77 to set the pilot control oil pressure, and adjust the third proportional throttle valve 78.3 to set the test flow; Step 15.2.4, opening the first safety shut-off valve group 39 and the second safety shut-off valve group 40 of the first accumulator 37 and the second accumulator 38; Step 15.2.5: Input a frequency sweep signal to the valve to be tested within the rated signal range, draw a Bode plot using the displacement feedback signal of the servo cylinder, and measure its frequency characteristics.

[0061] Note: Before introducing pilot control oil into the external control oil port of a servo valve or proportional valve, you must first confirm that the pressure of the pilot control oil matches the control pressure of the valve.

[0062] Step characteristics: Servo valves and proportional directional valves with electrical feedback: Step 16.1.1, open the second ball valve 60.9, the seventh ball valve 60.11, the thirteenth ball valve 60.4, the nineteenth ball valve 60.1, the twentieth ball valve 60.5, the twenty-first ball valve 41.1, the eighteenth ball valve 60.3, and the fifth ball valve 59.1; Step 16.1.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, and adjust the first proportional relief valve 75 to set the test pressure; Step 16.1.3, open the third outlet ball valve 62.1, the fourth ball valve 63.1, and the sixth ball valve 63.4, start the third pump group 02, adjust the second proportional relief valve 76 and the pressure reducing valve 77 to set the pilot control oil pressure, and adjust the third proportional throttle valve 78.3 to set the test flow; Step 16.1.4, close the first proportional throttle valve 78.1 and the second proportional throttle valve 78.2; Step 16.1.5, opening the first safety shut-off valve group 39 of the first accumulator 37; Step 16.1.6, input signal step response: within the rated signal range, input a step signal to the valve to be tested, and draw a step response characteristic curve through the displacement feedback signal of the valve to be tested, so as to detect the input signal step response characteristic of the valve to be tested; Step 16.1.7, load pressure step response: first close the first electromagnetic reversing valve 79.1, input a constant value signal to the valve to be tested, adjust the first proportional throttle valve 78.1, read out the steady-state set flow qvs and the pressure difference △P2 caused by flowing through the first proportional throttle valve 78.1; open the first electromagnetic reversing valve 79.1, adjust the second proportional throttle valve 78.2, read out qvs, and the pressure difference △P1 caused by the parallel oil circuit of the first proportional throttle valve 78.1 and the second proportional throttle valve 78.2; quickly close the first electromagnetic reversing valve 79.1 to cause a pressure step, record the flow response to a 50% to 90% step change from zero load pressure to the specified maximum load pressure, draw a step response characteristic curve, and thus detect the load pressure step response characteristic of the valve to be tested; Servo valve without electrical feedback, i.e. mechanical feedback: Step 16.2.1, open the second ball valve 60.9, the seventh ball valve 60.11, the twenty-first ball valve 41.1, the twenty-second ball valve 51, the twenty-third ball valve 52, the eighth ball valve 53, and the ninth ball valve 54; Step 16.2.2, open the first outlet ball valve 61.1, close the connecting ball valve 61.2 and the second outlet ball valve 61.3, start the first pump group 01.1, and adjust the first proportional relief valve 75 to set the test pressure; Step 16.2.3, open the third outlet ball valve 62.1, the fourth ball valve 63.1, and the sixth ball valve 63.4, start the third pump group 02, adjust the second proportional relief valve 76 and the pressure reducing valve 77 to set the pilot control oil pressure, and adjust the third proportional throttle valve 78.3 to set the test flow; Step 16.2.4, opening the first safety shut-off valve group 39 and the second safety shut-off valve group 40 of the first accumulator 37 and the second accumulator 38; Step 16.2.5, input signal step response: within the rated signal range, input a step signal to the valve to be tested, and draw a step response characteristic curve through the displacement feedback signal of the servo cylinder, so as to detect the input signal step response characteristic of the valve to be tested.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A hydraulic directional valve test system, characterized in that: Includes a hydraulic pump station system for providing hydraulic power during the test; The hydraulic pump station system comprises an oil tank system, a first main pump motor system and a second main pump motor system are connected in parallel to the oil tank system, the first main pump motor system is used to provide hydraulic power for the first test system (P1), and the second main pump motor system is used to provide hydraulic power for the second test system (P2); a control pump motor system is connected to the oil tank system, and the control pump motor system is used to provide hydraulic power for the third test system (P3); The first test system (P1), the second test system (P2) and the third test system (P3) are connected to a control valve test bench system for testing the valve to be tested.

2. A hydraulic directional valve test system according to claim 1, characterized in that: The entire hydraulic pump station system is set up inside the valve station pump station room; The oil tank system comprises a main oil tank (43), a plurality of oil drain ball valves (42) are arranged on the main oil tank (43), a plurality of sets of heaters (28) are arranged inside the main oil tank (43), and a liquid level sensor (25), a visual liquid level gauge (23), a temperature sensor (27), an oil return filter (92), an oil injection filter (30) and an oil sampling ball valve (91) are also installed on the main oil tank (43).

3. A hydraulic directional valve test system according to claim 2, characterized in that: The main oil tank (43) is connected to a cooling circulation device for cooling oil, and the cooling circulation device comprises a switch signaling ball valve (90) connected to the main oil tank (43), the switch signaling ball valve (90) is connected to the cooling pump motor unit (07.2) via a first flexible joint (89), the outlet of the cooling pump motor unit (07.2) is connected to the cooler (29) via a first non-return valve (66), the outlet of the cooler (29) is connected in parallel with a first ball valve (96), and the first ball valve (96) is connected to the main oil tank (43) via a filter (32).

4. A hydraulic directional valve test system according to claim 3, characterized in that: The cooler (29) is a plate-type cooler. The cooler (29) is connected to a water inlet ball valve (71.1) for cooling water to enter. An electromagnetic water valve (72) is installed on the pipeline after the water inlet ball valve (71.1). The cooling water outlet of the cooler (29) is connected to a water outlet ball valve (71.2).

5. A hydraulic directional valve test system according to claim 3, characterized in that: The first main pump motor system comprises a first oil suction ball valve (21.1) connected to the main oil tank (43); the first oil suction ball valve (21.1) is connected to the first pump group (01.1) via a second flexible joint (19.1); the oil outlet of the first pump group (01.1) is connected to the first high-pressure filter (33.1); the first high-pressure filter (33.1) is connected to the first test system (P1) via a second one-way valve (69.1) and a first outlet ball valve (61.1) in sequence; a first shock-resistant pressure gauge (47.1) and a first electromagnetic overflow valve (87.1) are installed on the pipeline between the first high-pressure filter (33.1) and the second one-way valve (69.1); a first proportional overflow valve (75), a first pressure sensor (50.1) and a connecting ball valve (61.2) are installed on the pipeline between the second one-way valve (69.1) and the first outlet ball valve (61.1); the other end of the connecting ball valve (61.2) is connected to the second test system (P2).

6. A hydraulic directional valve test system according to claim 5, characterized in that: The second main pump motor system comprises a second oil suction ball valve (21.2) connected to the main oil tank (43); the second oil suction ball valve (21.2) is connected to the second pump group (01.2) via a third flexible joint (19.2); the oil outlet of the second pump group (01.2) is connected to the second high-pressure filter (33.2); the second high-pressure filter (33.2) is connected to the second test system (P2) via a third one-way valve (69.2) and a second outlet ball valve (61.3) in sequence; a second seismic-resistant pressure gauge (47.2) and a second electromagnetic overflow valve (87.2) are installed on the pipeline between the second high-pressure filter (33.2) and the third one-way valve (69.2); the pipeline between the third one-way valve (69.2) and the second outlet ball valve (61.3) is connected to the ball valve (61.2) and is installed with a second pressure sensor (50.2).

7. A hydraulic directional valve test system according to claim 6, characterized in that: The control pump motor group system comprises a third oil suction ball valve (22.1) connected to the main oil tank (43); the third oil suction ball valve (22.1) is connected to the third pump group (02) via a fourth flexible joint (20.1); the oil outlet of the third pump group (02) is connected to the third high-pressure filter (34); the third high-pressure filter (34) is connected to the third test system (P3) via a fourth check valve (70.1) and a third outlet ball valve (62.1) in sequence; a third seismic-resistant pressure gauge (47.3) and a third electromagnetic overflow valve (87.3) are installed on the pipeline between the third pump group (02) and the third high-pressure filter (34); and a second proportional overflow valve (76) and a third pressure sensor (50.3) are installed on the pipeline between the fourth check valve (70.1) and the third outlet ball valve (62.1).

8. A hydraulic directional valve test system according to claim 7, characterized in that: The first pump group (01.1) adopts a constant pressure variable displacement plunger pump and is connected to a first drive motor (06.1) to provide pump oil power; The second pump group (01.2) adopts a constant pressure variable displacement piston pump and is connected to a second drive motor (06.2) to provide pump oil power; The third pump group (02) uses a constant pressure variable displacement pump and is connected to a third drive motor (07.1) to provide pumping oil power.

9. A hydraulic directional valve test system according to claim 7, characterized in that: The control valve test bench system is arranged in a valve test laboratory, and the valve test laboratory is connected to the valve station pump station room through a hydraulic pipeline; The control valve test bench system comprises a second ball valve (60.9) connected to a port of a first test system (P1), and a pipeline after the second ball valve (60.9) is connected to a P oil port of a valve to be tested through a seventh ball valve (60.11); It also includes a third ball valve (60.10) connected to the port of the second test system (P2), and the pipeline after the third ball valve (60.10) is connected to the P oil port of the valve to be tested through a seventh ball valve (60.11); It also includes a fourth ball valve (63.1) connected to the port of the third test system (P3), and the fourth ball valve (63.1) is connected to the X oil port of the valve to be tested through the pressure reducing valve (77) and the sixth ball valve (63.4); The pipeline between the third ball valve (60.10) and the seventh ball valve (60.11) is connected to a bypass flow regulating component and a seventeenth ball valve (60.2); the pipeline after the seventeenth ball valve (60.2) is connected to the B oil port of the valve to be tested through the second flow meter (74), the fifteenth ball valve (59.3) and the eleventh ball valve (60.7) in sequence; the B oil port of the valve to be tested is connected to a cavity of the dynamic measuring cylinder (80) through the eighth ball valve (53); The oil port A of the valve to be tested is simultaneously connected to the thirteenth ball valve (60.4), the twelfth ball valve (60.6) and the ninth ball valve (54); the thirteenth ball valve (60.4) is connected to the oil port B of the valve to be tested via the throttling loading assembly and the twentieth ball valve (60.5); the twelfth ball valve (60.6) is connected to the oil return line via the sixteenth ball valve (60.8), the first flow meter (73) and the eighteenth ball valve (60.3); the ninth ball valve (54) is connected to the other cavity of the dynamic measuring cylinder (80); The T oil port of the valve to be tested is connected to the twenty-first ball valve (41.1) and the fourteenth ball valve (41.2) at the same time, and the twenty-first ball valve (41.1) is connected to the oil return pipeline; the fourteenth ball valve (41.2) is connected to the Y oil port of the valve to be tested through the tenth ball valve (59.2), and is connected to the main oil tank (43) of the control pump motor system through the fifth ball valve (59.1); The pipeline after the fourth ball valve (63.1) is connected to the first accumulator (37) via the first safety stop valve group (39), and the first safety stop valve group (39) is also connected to the oil return pipeline; The T oil port of the valve to be tested is connected to the second accumulator (38) via a twenty-third ball valve (52) and a second safety stop valve group (40), and the second safety stop valve group (40) is simultaneously connected to the P oil port of the valve to be tested via a twenty-second ball valve (51).

10. A hydraulic directional valve test system according to claim 9, characterized in that: The bypass flow regulating component comprises a third proportional throttle valve (78.3) and an electromagnetic reversing valve (79.2) connected in parallel, and the other ports of the third proportional throttle valve (78.3) and the electromagnetic reversing valve (79.2) are connected to the oil return pipeline.

11. A hydraulic directional valve test system according to claim 10, characterized in that: The throttling loading assembly comprises a first proportional throttle valve (78.1), a second proportional throttle valve (78.2), a first electromagnetic reversing valve (79.1) and a nineteenth ball valve (60.1) connected in parallel.

12. A method for testing the performance of a valve to be tested using a hydraulic directional valve testing system as claimed in claim 11, characterized in that: Including the test of electromagnetic reversing valve and electromagnetic ball valve: Internal leakage test, the oil flows from the P port to the T port of the valve to be tested: Step 1.1, open the second ball valve (60.9), the seventh ball valve (60.11), the fourteenth ball valve (41.2), the fifteenth ball valve (59.3) and the eighteenth ball valve (60.3); Step 1.2, open the first outlet ball valve (61.1), close the connecting ball valve (61.2) and the second outlet ball valve (61.3), start the first pump group (01.1), adjust the first proportional relief valve (75) to set the test pressure, and adjust the third proportional throttle valve (78.3) to set the test flow; Step 1.3, the test valve is powered on or off to close the oil port from the P oil port to the T oil port, and the internal leakage is detected by the second flow meter (74); Internal leakage test, the oil flows from the P port to the A port of the valve to be tested: Step 2.1, open the second ball valve (60.9), the seventh ball valve (60.11), the twelfth ball valve (60.6), the fifteenth ball valve (59.3), and the eighteenth ball valve (60.3); Step 2.2, open the first outlet ball valve (61.1), close the connecting ball valve (61.2) and the second outlet ball valve (61.3), start the first pump group (01.1), adjust the first proportional relief valve (75) to set the test pressure, and adjust the third proportional throttle valve (78.3) to set the test flow; Step 2.3, the test valve is powered on or off to close the oil port P to the oil port A, and the internal leakage is detected by a second flow meter (74); Internal leakage test, the oil flows from the P port to the B port of the valve to be tested: Step 3.1, open the second ball valve (60.9), the seventh ball valve (60.11), the eleventh ball valve (60.7), the fifteenth ball valve (59.3), and the eighteenth ball valve (60.3); Step 3.2, open the first outlet ball valve (61.1), close the connecting ball valve (61.2) and the second outlet ball valve (61.3), start the first pump group (01.1), adjust the first proportional relief valve (75) to set the test pressure, and adjust the third proportional throttle valve (78.3) to set the test flow; Step 3.3, the test valve is powered on or off to close the oil port from the P oil port to the B oil port, and the internal leakage is detected by the second flow meter (74); Steady-state pressure difference-flow characteristic test: Step 4.1, open the second ball valve (60.9), the seventh ball valve (60.11), the thirteenth ball valve (60.4), the twentieth ball valve (60.5), the nineteenth ball valve (60.1), the fourteenth ball valve (41.2), the sixteenth ball valve (60.8), and the eighteenth ball valve (60.3); If it is a three-way valve, open the second ball valve (60.9), the seventh ball valve (60.11), the thirteenth ball valve (60.4), the twentieth ball valve (60.5), the eleventh ball valve (60.7), the sixteenth ball valve (60.8), and the eighteenth ball valve (60.3); Step 4.2, open the first outlet ball valve (61.1), close the connecting ball valve (61.2) and the second outlet ball valve (61.3), start the first pump group (01.1), adjust the first proportional relief valve (75) to set the test pressure, and adjust the third proportional throttle valve (78.3) to fully open the valve port for diversion; Step 4.3, closing the first proportional throttle valve (78.1) and the second proportional throttle valve (78.2); Step 4.4, the valve to be tested is energized or de-energized to make the valve port connected, and a signal is input to the third proportional throttle valve (78.3) to gradually reduce the diversion flow, and the flow of the valve to be tested is gradually increased from zero. The pressure difference-flow characteristic curve is plotted with the output flow as the X-axis and the pressure difference as the Y-axis.

13. A method for testing the performance of a valve to be tested using a hydraulic directional valve testing system as claimed in claim 11, characterized in that: Including servo valve and proportional valve tests: Internal leakage test: Step 5.1, open the second ball valve (60.9), the seventh ball valve (60.11), the fourteenth ball valve (41.2), the fifteenth ball valve (59.3), and the eighteenth ball valve (60.3); Step 5.2, open the first outlet ball valve (61.1), close the connecting ball valve (61.2) and the second outlet ball valve (61.3), start the first pump group (01.1), and adjust the first proportional relief valve (75) to set the test pressure; Step 5.3, open the connecting ball valve (61.2), the fourth ball valve (63.1), and the sixth ball valve (63.4), start the third pump group (02), adjust the second proportional relief valve (76) and the pressure reducing valve (77) to set the pilot control oil pressure, and adjust the third proportional throttle valve (78.3) to set the test flow; Step 5.4, input a periodic signal to the valve to be tested, detect the leakage of the T oil port through the second flow meter (74), open the tenth ball valve (59.2) and the twenty-first ball valve (41.1), close the fifth ball valve (59.1) and the fourteenth ball valve (41.2), and detect the leakage of the Y oil port through the second flow meter (74); Output flow-input signal characteristic test under constant valve pressure drop: Step 6.1, open the second ball valve (60.9), the seventh ball valve (60.11), the thirteenth ball valve (60.4), the nineteenth ball valve (60.1), the twentieth ball valve (60.5), the fourteenth ball valve (41.2), the sixteenth ball valve (60.8), the eighteenth ball valve (60.3), and the fifth ball valve (59.1); Step 6.2, open the first outlet ball valve (61.1), close the connecting ball valve (61.2) and the second outlet ball valve (61.3), start the first pump group (01.1), and adjust the first proportional relief valve (75) to set the test pressure; Step 6.3, open the third outlet ball valve (62.1), the fourth ball valve (63.1), and the sixth ball valve (63.4), start the third pump group (02), adjust the second proportional relief valve (76) and the pressure reducing valve (77) to set the pilot control oil pressure, and adjust the third proportional throttle valve (78.3) to set the test flow; Step 6.4, closing the first proportional throttle valve (78.1) and the second proportional throttle valve (78.2); Step 6.5, input a periodic signal to the valve to be tested, and draw its output flow-input signal characteristic curve with the given signal percentage as the X-axis and the flow signal as the Y-axis; Threshold characteristic test: Step 7.1, open the second ball valve (60.9), the seventh ball valve (60.11), the thirteenth ball valve (60.4), the nineteenth ball valve (60.1), the twentieth ball valve (60.5), the fourteenth ball valve (41.2), the sixteenth ball valve (60.8), the eighteenth ball valve (60.3), and the fifth ball valve (59.1); Step 7.2, open the first outlet ball valve (61.1), close the connecting ball valve (61.2) and the second outlet ball valve (61.3), start the first pump group (01.1), and adjust the first proportional relief valve (75) to set the test pressure; Step 7.3, open the third outlet ball valve (62.1), the fourth ball valve (63.1), and the sixth ball valve (63.4), start the third pump group (02), adjust the second proportional relief valve (76) and the pressure reducing valve (77) to set the pilot control oil pressure, and adjust the third proportional throttle valve (78.3) to set the test flow; Step 7.4, closing the first proportional throttle valve (78.1) and the second proportional throttle valve (78.2); Step 7.5, input a signal to the valve to be tested so that the output flow is 25% of the rated flow, then gradually reduce the input signal so that the flow also decreases accordingly, and slowly reduce the input signal to minimize the dynamic impact; Step 7.6, record the input signal when the flow rate starts to decrease; Step 7.7, calculate the threshold value by calculating the signal change increment according to the algebraic difference of the two recorded signal values, and draw a curve with the given signal percentage as the X-axis and the flow signal as the Y-axis; Step 7.8, repeat the test steps of steps 7.4 to 7.6 at 75% of the rated flow rate; Step 7.9, input the opposite signal and repeat the test steps of step 7.4 to step 7.7; Step 7.10, when testing the zero position of the zero opening and negative cover valve, use this threshold characteristic test method; Throttling regulation characteristics test: When from the oil supply port P to the working oil port A: Step 8.1.1, open the second ball valve (60.9), the seventh ball valve (60.11), the twelfth ball valve (60.6), the sixteenth ball valve (60.8), the eighteenth ball valve (60.3), and the fifth ball valve (59.1); Step 8.1.2, open the first outlet ball valve (61.1), close the connecting ball valve (61.2) and the second outlet ball valve (61.3), start the first pump group (01.1), and adjust the first proportional relief valve (75) to set the test pressure; Step 8.1.3, open the third outlet ball valve (62.1), the fourth ball valve (63.1), and the sixth ball valve (63.4), start the third pump group (02), adjust the second proportional relief valve (76) and the pressure reducing valve (77) to set the pilot control oil pressure, and adjust the third proportional throttle valve (78.3) to set the test flow; Step 8.1.4, slowly increase the input signal from zero to the rated positive value, and draw the flow curve from the oil supply port P to the working oil port A with the given signal as the X-axis and the flow signal as the Y-axis. From the working oil port A to the return oil port T: Step 8.2.1, open the second ball valve (60.9), the seventeenth ball valve (60.2), the sixteenth ball valve (60.8), the twelfth ball valve (60.6), the twenty-first ball valve (41.1), and the fifth ball valve (59.1); Step 8.2.2, open the first outlet ball valve (61.1), close the connecting ball valve (61.2) and the second outlet ball valve (61.3), start the first pump group (01.1), and adjust the first proportional relief valve (75) to set the test pressure; Step 8.2.3, open the third outlet ball valve (62.1), the fourth ball valve (63.1), and the sixth ball valve (63.4), start the third pump group (02), adjust the second proportional relief valve (76) and the pressure reducing valve (77) to set the pilot control oil pressure, and adjust the third proportional throttle valve (78.3) to set the test flow; Step 8.2.4, slowly increase the input signal from zero to the rated positive value, and draw a flow curve from the working oil port A to the return oil port T with the given signal as the X-axis and the flow signal as the Y-axis; From the oil supply port P to the working oil port B: Step 8.3.1, open the second ball valve (60.9), the seventh ball valve (60.11), the eleventh ball valve (60.7), the sixteenth ball valve (60.8), the eighteenth ball valve (60.3), and the fifth ball valve (59.1); Step 8.3.2, open the first outlet ball valve (61.1), close the connecting ball valve (61.2) and the second outlet ball valve (61.3), start the first pump group (01.1), and adjust the first proportional relief valve (75) to set the test pressure; Step 8.3.3, open the third outlet ball valve (62.1), the fourth ball valve (63.1), and the sixth ball valve (63.4), start the third pump group (02), adjust the second proportional relief valve (76) and the pressure reducing valve (77) to set the pilot control oil pressure, and adjust the third proportional throttle valve (78.3) to set the test flow; Step 8.3.4, slowly increase the input signal from zero to the rated positive value, and draw the flow curve from the oil supply port P to the working oil port B with the given signal as the X-axis and the flow signal as the Y-axis. From working oil port B to return oil port T: Step 8.4.1, open the second ball valve (60.9), the seventeenth ball valve (60.2), the sixteenth ball valve (60.8), the eleventh ball valve (60.7), the twenty-first ball valve (41.1), and the fifth ball valve (59.1); Step 8.4.2, open the first outlet ball valve (61.1), close the connecting ball valve (61.2) and the second outlet ball valve (61.3), start the first pump group (01.1), and adjust the first proportional relief valve (75) to set the test pressure; Step 8.4.3, open the third outlet ball valve (62.1), the fourth ball valve (63.1), and the sixth ball valve (63.4), start the third pump group (02), adjust the second proportional relief valve (76) and the pressure reducing valve (77) to set the pilot control oil pressure, and adjust the third proportional throttle valve (78.3) to set the test flow; Step 8.4.4, slowly increase the input signal from zero to the rated positive value, and draw the flow curve from the working oil port B to the return oil port T with the given signal as the X-axis and the flow signal as the Y-axis.

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