A digital hydraulic pump test bench and a method for verifying the control performance of a digital hydraulic pump

Abstract

The present application provides a digital hydraulic pump test bench and a method for verifying the control performance of a digital hydraulic pump. The digital hydraulic pump test bench provided by the present application includes a driving module and a loading module; wherein, the driving module includes a hydraulic pump under test, a DC speed regulating motor, a plurality of couplings, and a shock absorber. One end of the plurality of couplings is connected to the hydraulic pump under test, the other end is connected to the DC speed regulating motor, the shock absorber is connected to the DC speed regulating motor, and a plurality of sensors are installed on the hydraulic pump under test; the pressure oil port of the hydraulic pump under test is connected to the loading module, the loading module includes a bridge circuit and a loading circuit, a plurality of pressure oil ports are respectively connected to the first series connection point and the second series connection point of the bridge circuit, and the parallel connection point of the bridge circuit is connected to the loading circuit. The digital hydraulic pump test bench and the method for verifying the control performance of a digital hydraulic pump provided by the present application are used to verify the key control performance of the digital hydraulic pump and have a wide range of applications.

Description

Technical Field

[0001] This application relates to the field of hydraulic technology, and particularly to a digital hydraulic pump test bench and a method for verifying the control performance of a digital hydraulic pump. Background Art

[0002] A digital hydraulic pump is a core component of a hydraulic system, and its performance directly affects the efficiency, stability, and reliability of the entire system. Through control performance tests, the operating characteristics of the digital hydraulic pump under different working conditions can be evaluated, including key parameters such as flow rate, pressure, efficiency, response time, and dynamic performance. Secondly, the digital hydraulic pump adopts advanced electronic control technology, and the control performance test can verify the accuracy and response speed of its control algorithm, thereby ensuring the high efficiency and accuracy of the system in practical applications. The control performance test can also help to discover potential design defects and operating problems, providing data support for improving the design and optimizing the control strategy. Finally, these test results can guide the selection and application of digital hydraulic pumps, improving the overall performance and reliability of engineering projects. Therefore, it is essential to conduct control performance tests on digital hydraulic pumps.

[0003] Currently, control performance tests on digital hydraulic pumps are mainly based on traditional digital hydraulic pump test benches. However, their application scope is single, they cannot take into account both open-loop and closed-loop pumps, and they cannot verify the key control performance of digital hydraulic pumps, lacking the performance verification function for digital hydraulic pumps. Therefore, there is an urgent need for a digital hydraulic pump test bench that can verify the key control performance of digital hydraulic pumps and has a wide application scope. Summary of the Invention

[0004] In view of this, this application provides a digital hydraulic pump test bench and a method for verifying the control performance of a digital hydraulic pump, so as to verify the key control performance of the digital hydraulic pump and have a wide application scope.

[0005] Specifically, this application is implemented through the following technical solutions:

[0006] The first aspect of the present application provides a digital hydraulic pump test bench, which includes a driving module and a loading module. Among them, the driving module includes a hydraulic pump under test, a DC speed-regulating motor, multiple couplings, and shock absorbers. When verifying the performance of the hydraulic pump under test, it provides high-pressure oil to the loading module. There is a pressure oil port on the hydraulic pump under test, and the pressure oil port is connected to the loading module. One end of the multiple couplings is connected to the hydraulic pump under test, and the other end is connected to the DC speed-regulating motor. The shock absorber is connected to the DC speed-regulating motor. Multiple sensors are installed on the hydraulic pump under test, and the type of the sensors is determined according to the type of the hydraulic pump under test and the performance to be verified. The sensors are used to collect the performance parameters of the hydraulic pump under test during the loading process, and the performance parameters are used to verify the performance of the hydraulic pump under test.

[0007] The pressure oil port of the hydraulic pump under test is connected to the loading module. The loading module includes a bridge circuit and a loading circuit. Multiple pressure oil ports are respectively connected to the first series connection point and the second series connection point of the bridge circuit. The parallel connection point of the bridge circuit is connected to the loading circuit. The loading module is used to determine the flow direction of the high-pressure oil according to the performance to be verified of the hydraulic pump under test, apply a load to the hydraulic pump under test based on the flow direction of the high-pressure oil, and control the loading of the hydraulic pump under test.

[0008] The second aspect of the present application provides a method for verifying the control performance of a digital hydraulic pump. The method is applied to any digital hydraulic pump test bench provided in the first aspect of the present application. The method includes:

[0009] Determine the flow direction of the high-pressure oil according to the performance to be verified of the hydraulic pump under test;

[0010] Apply a load to the hydraulic pump under test based on the flow direction of the high-pressure oil, and control the loading of the hydraulic pump under test;

[0011] Verify the performance of the hydraulic pump under test based on the performance parameters collected by the sensors during the loading process of the hydraulic pump under test.

[0012] The digital hydraulic pump test bench and the method for verifying the control performance of the digital hydraulic pump provided by this application. On the first hand, a DC speed control motor is used as the driving device, which can achieve speed closed-loop control, improve the accuracy of the high-pressure oil output by the hydraulic pump under test, and can test the optimal speed range of the hydraulic pump under test, improving the accuracy and reliability of verifying the control performance of the hydraulic pump under test. On the second hand, by designing a shock absorber, the vibration generated during the operation of the DC speed control motor can be reduced, thereby reducing the interference to the hydraulic pump under test and improving the accuracy and reliability of verifying the control performance of the hydraulic pump under test. On the third hand, by setting the hydraulic pump test bench as a driving module and a loading module, installing the hydraulic pump under test on the driving module, providing high-pressure oil to the loading module by the driving module, and the loading module applying a load to the hydraulic pump under test based on the performance to be verified of the hydraulic pump under test to control the loading of the hydraulic pump under test, the working load of the hydraulic pump under test can be accurately adjusted, and then the output pressure and flow rate of the hydraulic pump under test can be controlled, avoiding idling or overspeed operation of the hydraulic pump under test and improving stability. Moreover, based on the sensors installed on the hydraulic pump under test, the performance parameters of the hydraulic pump under test during the loading process are collected in real time, and in the follow-up, the performance of the hydraulic pump under test can be verified based on the performance parameters corresponding to the performance to be verified and the performance verification method, realizing the verification of the key control performance of the hydraulic pump, and realizing new functions such as multi-source state detection and life prediction of the hydraulic pump, providing test conditions for the factory test and research and development of new hydraulic pumps. Description of the Drawings

[0013] Figure 1 Schematic structural diagram of the first embodiment of the digital hydraulic pump test bench provided by this application;

[0014] Figure 2 Schematic structural diagram of the driving module shown in an exemplary embodiment of this application;

[0015] Figure 3 Schematic structural diagram of the loading module shown in an exemplary embodiment of this application;

[0016] Figure 4 Schematic structural diagram of the oil replenishing module shown in an exemplary embodiment of this application;

[0017] Figure 5 Flow chart of the first embodiment of the method for verifying the performance of the digital hydraulic pump provided by this application;

[0018] Description of the Reference Numerals:

[0019] 1, 25: DC speed control motor

[0020] 2: Shock absorber

[0021] 3, 5: Coupling

[0022] 4: Torque sensor

[0023] 6, 17: Proportional overflow valve

[0024] 7: Rotational speed sensor

[0025] 8: Swing angle sensor

[0026] 9: Hydraulic pump under test

[0027] 10: Vibration sensor

[0028] 11, 14: Temperature sensor

[0029] 12, 13, 16, 20: Check valve

[0030] 15, 21: High-pressure sensor

[0031] 18: Pressure valve cover plate

[0032] 19: Electromagnetic directional seat valve

[0033] 22: Low-pressure sensor

[0034] 23: Flowmeter

[0035] 24: Two-way logic unit

[0036] 26: Safety valve

[0037] 27: High-pressure filter

[0038] 28: Fixed-displacement pump

[0039] 29: Suction filter Detailed implementation manners

[0040] Here, exemplary embodiments will be described in detail, and examples thereof are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present application.

[0041] The terms used in the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms "a", "the" and "said" used in the present application are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0042] It should be understood that although the terms first, second, third, etc. may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "when" or "while" or "in response to a determination".

[0043] Specific embodiments are given below to introduce the technical solutions of this application in detail.

[0044] Figure 1 It is a schematic structural diagram of the first embodiment of the digital hydraulic pump test bench provided by this application. Please refer to Figure 1 , the digital hydraulic pump test bench provided in this embodiment, the hydraulic pump test bench includes a drive module and a loading module; wherein, the drive module includes a hydraulic pump under test, a DC speed control motor, a plurality of couplings, and shock absorbers, and is used to provide high-pressure oil to the loading module when verifying the performance of the hydraulic pump under test. There is a pressure oil port on the hydraulic pump under test, and the pressure oil port is connected to the loading module. One end of the plurality of couplings is connected to the hydraulic pump under test, and the other end is connected to the DC speed control motor. The shock absorber is connected to the DC speed control motor. A plurality of sensors are installed on the hydraulic pump under test, and the type of the sensor is determined according to the type of the hydraulic pump under test and the performance to be verified. The sensor is used to collect the performance parameters of the hydraulic pump under test during the loading process, wherein the performance parameters are used to verify the performance of the hydraulic pump under test;

[0045] The pressure oil port of the hydraulic pump under test is connected to the loading module. The loading module includes a bridge circuit and a loading circuit. A plurality of the pressure oil ports are respectively connected to the first series connection point and the second series connection point of the bridge circuit. The parallel connection point of the bridge circuit is connected to the loading circuit. The loading module is used to determine the flow direction of the high-pressure oil based on the performance to be verified of the hydraulic pump under test, apply a load to the hydraulic pump under test based on the flow direction of the high-pressure oil, and control the loading of the hydraulic pump under test.

[0046] Specifically, please refer to Figure 1 , the digital hydraulic pump test bench includes a drive module and a loading module. Among them, the drive module includes a hydraulic pump under test, a DC speed control motor, a plurality of couplings, and shock absorbers. The hydraulic pump under test is installed on the drive module. One end of the plurality of couplings is connected to the hydraulic pump under test, and the other end of the plurality of couplings is connected to the DC speed control motor. The shock absorber is connected to the DC speed control motor. A plurality of sensors are installed on the hydraulic pump under test. There is a pressure oil port on the hydraulic pump under test, and the pressure oil port of the hydraulic pump under test is connected to the loading module.

[0047] It should be noted that the hydraulic pumps to be measured mentioned in this application are all digital hydraulic pumps.

[0048] Furthermore, the multiple sensors installed on the hydraulic pump to be measured have multiple types. These multiple types of sensors are installed on the hydraulic pump to be measured simultaneously to monitor the performance parameters of the hydraulic pump to be measured during the loading process in real time. When determining the performance to be verified of the hydraulic pump to be measured, only the corresponding sensors need to be read based on the performance parameters required for the performance to be verified (for example, when the performance to be verified is pressure resistance performance and pressure stability, the performance parameters collected by the pressure sensor are usually read; when the performance to be verified is flow characteristics, flow accuracy, and response time, the flow sensor is usually read to collect relevant performance parameters; when the performance to be verified is position accuracy and response speed, the performance parameters collected by the displacement sensor are usually read), rather than reading all the sensors.

[0049] Furthermore, when the drive module is used to verify the performance of the hydraulic pump to be measured, it provides high-pressure oil to the loading module. The loading module is used to determine the flow direction of the high-pressure oil provided by the drive module based on the performance to be verified of the hydraulic pump to be measured, apply a load to the hydraulic pump to be measured based on the flow direction, and control the loading of the hydraulic pump to be measured.

[0050] In specific implementation, when it is necessary to verify the performance to be verified of the hydraulic pump to be measured, the drive module generates high-pressure oil through driving action and transmits the generated high-pressure oil to the loading module. After receiving the high-pressure oil transmitted by the drive module, the loading module determines the flow direction of the high-pressure oil based on the performance to be verified of the hydraulic pump to be measured, and applies a load to the hydraulic pump to be measured based on the determined flow direction to control the loading of the hydraulic pump to be measured. During the loading process of the hydraulic pump to be measured, the sensors collect the performance parameters of the hydraulic pump to be measured in real time. Based on the performance to be verified of the hydraulic pump to be measured, the performance parameters to be collected and the corresponding sensor types are determined, and the performance of the hydraulic pump to be measured is verified based on the performance parameters collected by the sensors of this sensor type.

[0051] Next, the specific structures of each module of the digital hydraulic pump test bench will be introduced.

[0052] Figure 2 It is a schematic structural diagram of the drive module shown in an exemplary embodiment of this application. Please refer to Figure 2 , the drive module includes a hydraulic pump 9 to be measured, a DC speed-regulating motor 1, a shock absorber 2, a coupling 3, a coupling 5, and a proportional solenoid valve 6. Among them, the hydraulic pump 9 to be measured is connected to the DC speed-regulating motor 1 through the coupling 3 and the coupling 5; multiple sensors are installed on the hydraulic pump 9 to be measured; the proportional solenoid valve 6 is connected to the hydraulic pump 9 to be measured; the shock absorber 2 is connected to the DC speed-regulating motor 1.

[0053] It should be noted that, in combination with the above description, multiple sensors have multiple types. Please continue to refer to Figure 2 , in the drive module, the multiple sensors include a rotational speed sensor 7, a torque sensor 4, a swash plate angle sensor 8, and a vibration sensor 10.

[0054] Furthermore, the rotational speed sensor 7 monitors the output rotational speed of the DC speed regulating motor 1, that is, the input rotational speed of the hydraulic pump 9 to be measured. Based on the magnitude relationship between the output rotational speed and the preset rotational speed, the rotational speed of the DC speed regulating motor 1 is adjusted and controlled to ensure that the input rotational speed of the hydraulic pump 9 to be measured is within the preset rotational speed range, thereby improving the accuracy of the output flow rate of the hydraulic pump 9 to be measured. The torque sensor 4 monitors the output torque of the DC speed regulating motor 1, that is, the input torque of the hydraulic pump 9 to be measured, and evaluates the mechanical performance and energy conversion efficiency of the hydraulic pump 9 to be measured by comparing it with the input power. The swash plate angle sensor 8 monitors the swash plate angle of the hydraulic pump 9 to be measured. Based on the magnitude relationship between the output angle and the preset angle, the swash plate position of the hydraulic pump 9 to be measured is adjusted and controlled to improve the accuracy of the output flow rate of the hydraulic pump 9 to be measured. The vibration sensor 10 is a three-axis vibration sensor, which is connected to the hydraulic pump 9 to be measured by magnetic adsorption, and real-time monitors the radial vibration and axial vibration of the hydraulic pump 9 to be measured, so as to evaluate the working state of the hydraulic pump 9 to be measured, monitor potential faults, and provide an important basis for the life prediction of the hydraulic pump 9 to be measured.

[0055] Furthermore, the DC speed regulating motor 1 is used to drive the hydraulic pump 9 to be measured. The DC speed regulating motor 1 performs speed closed-loop regulation according to its own rotational speed and the set speed, and adjusts its own rotational speed based on the received feedback signal to control the operating speed and oil volume of the hydraulic pump 9 to be measured. The hydraulic pump 9 to be measured is used to provide stable high-pressure oil according to the driving rotational speed of the DC speed regulating motor 1. The shock absorber 2 is used to absorb and reduce the vibration generated during the operation of the DC speed regulating motor 1 to protect the hydraulic pump 9 to be measured. The proportional solenoid valve 6 is used to adjust the flow rate or pressure of the hydraulic oil according to the control signal of the system, precisely control the flow rate output by the hydraulic pump 9 to be measured, and ensure that the performance test of the hydraulic pump 9 to be measured is carried out within the set range.

[0056] In specific implementation, the DC speed regulating motor 1 starts and drives the hydraulic pump 9 to be measured to operate. The rotational speed of the DC speed regulating motor 1 can be adjusted to control the flow rate output of the hydraulic pump 9 to be measured. The shock absorber 2 absorbs and reduces the vibration generated during the operation of the DC speed regulating motor 1. The coupling 3 and the coupling 5 transmit the rotational motion of the DC speed regulating motor 1 to the hydraulic pump 9 to be measured. Driven by the DC speed regulating motor 1, the hydraulic pump 9 to be measured outputs high-pressure oil. The sensors real-time monitor the operating state (such as rotational speed, pressure, flow rate, swash plate angle) of the hydraulic pump 9 to be measured and feed the data back to the control system. The proportional solenoid valve 6 adjusts the flow rate or pressure of the high-pressure oil output by the hydraulic pump 9 to be measured according to the control signal of the system to ensure that the performance test of the hydraulic pump 9 to be measured is carried out within the set range.

[0057] For the digital hydraulic pump test bench provided in this embodiment, on the one hand, a DC speed control motor is used as the driving device, which can achieve speed closed-loop control, improve the accuracy of the high-pressure oil output by the hydraulic pump under test, and can test the optimal speed range of the hydraulic pump under test, improving the accuracy and reliability of the verification of the control performance of the hydraulic pump under test. On the other hand, by designing a proportional solenoid valve and a sensor, the high-pressure oil output by the hydraulic pump under test can be monitored and adjusted in real time, ensuring that the pressure of the hydraulic pump under test is within the set range and preventing pressure overshoot caused by system overload or failure of the hydraulic pump under test. On the third hand, by designing a shock absorber, the vibration generated during the operation of the DC speed control motor can be reduced, thereby reducing the interference to the hydraulic pump under test and improving the accuracy and reliability of the verification of the control performance of the hydraulic pump under test.

[0058] Figure 3 The structure diagram of the loading module shown in an exemplary embodiment of the present application. Please refer to Figure 3 , the loading module includes a bridge circuit and a loading circuit. Multiple oil delivery ports of the hydraulic pump under test are respectively connected to the first series connection point and the second series connection point of the bridge circuit, and the parallel connection point of the bridge circuit is connected to the loading circuit.

[0059] Furthermore, the bridge circuit determines the flow direction of the high-pressure oil based on the performance to be verified of the hydraulic pump 9 under test, and controls the high-pressure oil to flow to the loading circuit. The loading circuit applies a load to the hydraulic pump 9 under test based on the flow direction of the high-pressure oil, and controls the loading of the hydraulic pump 9 under test.

[0060] Specifically, the bridge circuit includes multiple check valves, and the multiple check valves work together to control the bidirectional flow of the high-pressure oil. Please continue to refer to Figure 3 , the multiple check valves include check valve 12, check valve 13, check valve 16, and check valve 20. Among them, check valve 12 and check valve 13 are connected in series, and their series connection point is the first series connection point. Check valve 16 and check valve 20 are connected in series, and their series connection point is the second series connection point. Check valve 12 and check valve 16 are connected in parallel, and their connection point is the parallel connection point, located at the same end of the bridge circuit. Check valve 13 and check valve 20 are connected in parallel, and their connection point is the parallel connection point, located at the other end of the bridge circuit.

[0061] Furthermore, please continue to refer to Figure 3, multiple high-pressure sensors are provided on the pressure return circuit of the bridge circuit. Among them, the high-pressure sensor 15 is connected to the second oil inlet P2 of the loading module, and the high-pressure sensor 21 is connected to the first oil inlet P3 of the loading module. The multiple high-pressure sensors work together to monitor the output pressure of the hydraulic pump 9 to be measured and feed the measured pressure data back to the control system for closed-loop control of the loading pressure. In the closed-loop control system, the actual pressure value is compared with the set pressure value. If the deviation exceeds the set range, the control system will adjust the proportional relief valve or other control components to keep the pressure within the preset range and ensure the accuracy of the loading process. A low-pressure sensor 22 and a flow meter 23 are provided on the oil return circuit of the bridge circuit. The low-pressure sensor 22 is connected to the output end of the bridge circuit, and the flow meter 23 is connected to the output end of the bridge circuit. The low-pressure sensor 22 is used to monitor the back pressure in the oil return circuit (i.e., the oil pressure before returning to the hydraulic pump to be measured) to ensure that the back pressure is within a safe range and prevent too high or too low back pressure from affecting the normal operation of the hydraulic system or damaging hydraulic components. The flow meter 23 is used to monitor the oil flow in the oil return circuit (i.e., the oil volume before returning to the hydraulic pump) to ensure that the oil volume is within a safe range. Multiple temperature sensors are provided in the bridge circuit. Among them, the temperature sensor 11 is connected to the second oil inlet P2 of the loading module, and the temperature sensor 14 is connected to the first oil inlet P3 of the loading module. The multiple temperature sensors work together to monitor the temperature of the high-pressure oil discharged by the hydraulic pump 9 to be measured. Based on the relationship between this temperature and the preset temperature, the temperature of the high-pressure oil is adjusted so that the high-pressure oil is always within the set viscosity range. It should be noted that the viscosity of the high-pressure oil changes with the temperature, and the feedback signal provided by the temperature sensor can be used to adjust the temperature control system to keep the temperature of the high-pressure oil within the set range, thereby ensuring the stability of the viscosity of the high-pressure oil.

[0062] It should be noted that due to the different performance to be verified of the hydraulic pump 9 to be measured, the flow direction of the high-pressure oil is different, and the loading direction of the hydraulic pump 9 to be measured is also different.

[0063] In specific implementation, in a possible implementation manner, when controlling the forward loading of the hydraulic pump 9 to be measured, the pressure oil port P1 of the hydraulic pump 9 to be measured is connected to the first oil inlet P3 of the loading module. The one-way valve 12 is closed (to prevent high-pressure oil from flowing into the oil replenishing circuit or the reverse circuit), the one-way valve 13 is opened (to allow high-pressure oil to flow to the one-way valve 20), the one-way valve 20 is opened, and the one-way valve 16 is closed (to prevent high-pressure oil from entering the reverse circuit). The high-pressure oil passes through the pressure oil port P1 and sequentially enters the loading circuit through the first oil inlet P3, the one-way valve 13, and the one-way valve 20, and flows to the fuel tank through the second oil inlet P2.

[0064] In another possible implementation, when controlling the reverse loading of the hydraulic pump 9 under test, the pressure oil port P1 of the hydraulic pump 9 under test is connected to the second oil inlet P4 of the loading module. The one-way valve 12 is opened (allowing high-pressure oil to flow towards the one-way valve 20), the one-way valve 13 is closed (preventing high-pressure oil from flowing towards the one-way valve 20), the one-way valve 16 is opened (allowing high-pressure oil to flow towards the reverse part of the bridge circuit after passing through the one-way valve 13), and the one-way valve 20 is closed (preventing high-pressure oil from flowing back from the bridge circuit to P3 of the loading module). The high-pressure oil passes through the pressure oil port P1 and sequentially enters the loading circuit through the second oil inlet P4, the one-way valve 12, and the one-way valve 20, and flows back to the fuel tank through the second oil inlet P2.

[0065] For the digital hydraulic pump test bench provided in this embodiment, when setting up the bridge circuit, on the one hand, through the configuration of multiple one-way valves, the bidirectional flow of high-pressure oil can be achieved. That is, regardless of the direction in which the high-pressure oil enters the bridge circuit, the expected flow path can be achieved through the series and parallel one-way valves, enabling the loading module to support bidirectional loading and control, and realizing the bidirectional loading of the hydraulic pump under test. On the other hand, by controlling the flow direction of the high-pressure oil through the bridge circuit, various working conditions of the hydraulic pump under test in actual applications can be simulated, the performance of the hydraulic pump under test under various working conditions can be comprehensively verified, and the working conditions can be quickly adjusted according to different verification requirements without replacing equipment, reducing the need for additional test equipment, having high flexibility, helping to save resources and reduce test costs, improving the accuracy and reliability of performance verification, and realizing refined performance analysis and fault diagnosis. On the third hand, through the multiple one-way valves in the bridge circuit, the occurrence of unexpected reverse flow in the bridge circuit can be effectively prevented, protecting the hydraulic pump under test and other equipment from damage, and ensuring the safe operation of the system. And it can balance the pressure in two different directions. No matter which direction the high-pressure oil flows in, the bridge circuit can reduce the pressure shock through reasonable oil distribution and pressure regulation, thereby reducing the mechanical stress on the pipeline and equipment and extending the service life of the system components.

[0066] Specifically, please continue to refer to Figure 3 , the loading circuit includes a two-way logic unit 24, a proportional relief valve 17, a pressure valve cover plate 18, and an electromagnetic reversing seat valve 19; wherein, the oil inlet of the electromagnetic reversing seat valve 19 is connected to the oil outlet of the bridge circuit; the oil outlet of the electromagnetic reversing seat valve 19 is connected to the oil inlet of the proportional relief valve 17; the outlet of the proportional relief valve 17 is connected to the oil inlet of the pressure valve cover plate 18; the outlet of the pressure valve cover plate 18 is connected to the oil return port and the fuel tank; the input end of the two-way logic unit 24 is connected to the pressure valve cover plate 18, and the output end is connected to the proportional relief valve 17 and the electromagnetic reversing seat valve 19.

[0067] Furthermore, the pressure valve cover plate 18 is used to close the pressure valve and send the pressure signal collected by the low-pressure sensor 22 to the two-way logic unit 24. The two-way logic unit 24 controls the states of the proportional overflow valve 17 and the electromagnetic reversing valve 19 based on the pressure signal sent by the pressure valve cover plate 18; the electromagnetic reversing valve 19 is used to control the flow direction of the high-pressure hydraulic oil, adjusts the flow direction of the high-pressure hydraulic oil based on the control of the two-way logic unit 24, and performs the operation of loading or unloading the load; the proportional overflow valve 17 is used to adjust the pressure of the loading circuit based on the control of the two-way logic unit 24.

[0068] In specific implementation, the high-pressure hydraulic oil enters the two-way logic unit 24 through a bridge circuit, successively passes through the proportional overflow valve 17, the pressure valve cover plate 18 and the electromagnetic reversing valve 19, and is ready for loading. When the pressure of the high-pressure hydraulic oil reaches the set pressure of the proportional overflow valve 17, the overflow process starts, and a pressure difference is established at both ends of the spool of the two-way logic unit 24. The spool rises, and the high-pressure hydraulic oil in the loading circuit starts to overflow at the set pressure, thus entering the loading working condition.

[0069] The digital hydraulic pump test bench provided by this embodiment, by setting the proportional overflow valve, on the one hand, the proportional overflow valve can accurately adjust the load applied to the hydraulic pump to be tested according to the set value, can achieve high-precision pressure control, and ensure that the load pressure applied to the hydraulic pump to be tested is accurate. On the other hand, by flexibly adjusting the pressure, the working conditions of the hydraulic pump to be tested under different pressure conditions can be simulated, such as normal operation, pressure shock and system vibration, etc. On the third hand, the proportional overflow valve monitors the pressure of the high-pressure hydraulic oil flowing to the hydraulic pump to be tested based on the set maximum pressure value. When the set value is exceeded, the proportional overflow valve releases the excess oil to the oil tank to prevent the system from being damaged due to excessive pressure and ensure the safety of the test equipment and personnel.

[0070] It should be noted that the hydraulic pump to be tested includes an open circuit and a closed circuit. In the open circuit, the hydraulic oil is sucked from the oil tank (storage tank), pressurized by the hydraulic pump to be tested and then delivered to the actuator (such as a hydraulic cylinder or a hydraulic motor). After the actuator completes the execution, the hydraulic oil is delivered back to the oil tank, and the hydraulic oil is cooled and filtered through the oil tank and then recycled. In the closed circuit, the pressure oil port of the hydraulic pump to be tested is directly connected to the oil inlet of the hydraulic motor, and the oil return port of the hydraulic motor is directly connected to the oil inlet of the hydraulic pump to be tested. The hydraulic oil circulates between the hydraulic pump to be tested and the actuator and does not directly return to the oil tank.

[0071] The hydraulic pump to be tested in the above embodiment mainly aims at the case where the hydraulic pump to be tested is an open pump. When the hydraulic pump to be tested is a closed pump, the hydraulic pump test bench further includes a make-up oil module.

[0072] Specifically, when the hydraulic pump 9 under test is a closed-loop circuit, the digital hydraulic pump test bench further includes a make-up oil module. Among them, the make-up oil module is connected to the loading module. The make-up oil module is used to supply low-pressure oil to the loading module when the outlet pressure of the hydraulic pump 9 under test is lower than the preset value.

[0073] Figure 4 The schematic diagram of the principle of the make-up oil module shown in an exemplary embodiment of the present application. Please refer to Figure 4 , the make-up oil module includes a DC speed-regulating motor 25, a safety valve 26, a high-pressure filter 27, a fixed-displacement pump 28, and a suction filter 29; among them, the DC speed-regulating motor 25 is connected to the fixed-displacement pump 28; the suction filter 29 is located at the suction end of the fixed-displacement pump 28; the fixed-displacement pump 28 is connected to the high-pressure filter 27; the safety valve 26 is located between the outlet of the fixed-displacement pump 28 and the fuel tank.

[0074] Further, the DC speed-regulating motor 25 starts and drives the fixed-displacement pump 28. The fixed-displacement pump 28 sucks in low-pressure oil from the fuel tank through the suction filter 29, and the low-pressure oil reaches the loading module through the high-pressure filter 27; the high-pressure filter 27 is used to remove impurities in the low-pressure oil, and the safety valve 26 is used to overflow the excess oil at the outlet of the fixed-displacement pump 28 back to the fuel tank when the outlet pressure of the fixed-displacement pump 28 is higher than the preset pressure.

[0075] The digital hydraulic pump test bench provided in this embodiment, when the hydraulic pump under test is a closed pump and the outlet pressure of the hydraulic pump under test is lower than the preset value, sets a make-up oil module to supply low-pressure oil to the loading module, and then provides sufficient load to the hydraulic pump under test. On the one hand, since the fixed-displacement pump can overcome the pressure difference in the closed-loop circuit and inject low-pressure oil into the closed-loop circuit, thereby making up for the insufficient oil volume caused by leakage, expansion or other reasons, ensuring that the closed pump can maintain normal oil circulation, effectively preventing the air suction phenomenon, and ensuring the normal operation and stability of the hydraulic pump under test. And, the DC speed-regulating motor can adjust the output flow of the fixed-displacement pump according to the real-time demand of the fixed-displacement pump, so as to accurately make up the required low-pressure oil, enabling the make-up oil module to flexibly provide the required oil volume. On the other hand, during the performance verification process, the make-up oil module can automatically supply low-pressure oil to the loading module when the outlet pressure of the hydraulic pump under test is lower than the preset value, ensuring the smooth progress of the performance verification, reducing the situation of operation interruption, improving the test efficiency, and improving the test accuracy. On the third hand, the hydraulic pump test bench takes into account both open pumps and closed pumps, has a wide range of applications, and does not need to switch to other hydraulic pump test benches when different hydraulic pumps need to be verified, which is more convenient and improves the test efficiency.

[0076] For the digital hydraulic pump test bench provided in this embodiment, on the one hand, a DC speed control motor is used as the driving device, which can achieve speed closed-loop control, improve the accuracy of the low-pressure oil output by the fixed-displacement pump, and can test the optimal speed range of the fixed-displacement pump, improving the accuracy and reliability of the verification of the control performance of the hydraulic pump under test. On the other hand, by designing a safety valve and a high-pressure filter to monitor and adjust the low-pressure oil output by the fixed-displacement pump in real time, it can ensure that the pressure of the fixed-displacement pump is within the set range and prevent pressure overshoot caused by system overload or fixed-displacement pump failure. On the third hand, by setting a high-pressure filter and a suction filter, the cleanliness of the low-pressure oil can be guaranteed and the interference with the performance verification results can be reduced.

[0077] The digital hydraulic pump test bench provided in this embodiment, on the one hand, uses a DC speed control motor as the driving device, which can achieve speed closed-loop control, improve the accuracy of the high-pressure oil output by the hydraulic pump under test, and can test the optimal speed range of the hydraulic pump under test, improving the accuracy and reliability of the verification of the control performance of the hydraulic pump under test. On the other hand, by designing shock absorbers, the vibration generated during the operation of the DC speed control motor can be reduced, thereby reducing the interference to the hydraulic pump under test and improving the accuracy and reliability of the verification of the control performance of the hydraulic pump under test. On the third hand, by setting the hydraulic pump test bench as a driving module and a loading module, installing the hydraulic pump under test on the driving module, and providing high-pressure oil to the loading module by the driving module, the loading module applies a load to the hydraulic pump under test based on the performance to be verified of the hydraulic pump under test to control the loading of the hydraulic pump under test, the working load of the hydraulic pump under test can be accurately adjusted, and then the output pressure and flow rate of the hydraulic pump under test can be controlled, avoiding idling or overspeed operation of the hydraulic pump under test and improving stability. Moreover, based on the sensors installed on the hydraulic pump under test, the performance parameters of the hydraulic pump under test during the loading process are collected in real time, and in the follow-up, the performance of the hydraulic pump under test can be verified based on the performance parameters corresponding to the performance to be verified and the performance verification method, realizing the verification of the key control performance of the hydraulic pump, and realizing new functions such as multi-source state detection and life prediction of the hydraulic pump, providing test conditions for the factory test and research and development of new hydraulic pumps. On the fourth hand, when the hydraulic pump under test is a closed pump, the hydraulic pump test bench is also provided with a supplementary oil module for providing low-pressure oil to the loading module, which can prevent cavitation and ensure the normal operation and stability of the hydraulic pump under test. Compared with the traditional hydraulic pump test bench, it takes into account both open and closed pumps, has a wide application range, does not require switching to other hydraulic pump test benches when different hydraulic pumps need to be verified, is more convenient, improves the test efficiency, and is more conducive to production application. On the fifth hand, based on the performance to be verified, different flow directions of the high-pressure oil are determined, and then the loading of the hydraulic pump under test is controlled based on different flow directions to verify the performance based on the performance parameters during the loading process. Various working conditions of the hydraulic pump under test in actual applications can be simulated, the performance of the hydraulic pump under test under various working conditions can be comprehensively verified, and the working conditions can be quickly adjusted according to different verification requirements without replacing equipment, reducing the need for additional test equipment, having high flexibility, helping to save resources and reduce test costs, improving the accuracy and reliability of performance verification, and realizing refined performance analysis and fault diagnosis.

[0078] Corresponding to the foregoing embodiment of a digital hydraulic pump test bench, the present application also provides an embodiment of a method for verifying the control performance of a digital hydraulic pump.

[0079] Figure 5 It is a flowchart of the first embodiment of the method for verifying the control performance of a digital hydraulic pump provided by the present application. Please refer to Figure 5, the method provided in this embodiment is applied to the digital hydraulic pump test bench described in any item of this application; the method includes:

[0080] S501. Determine the flow direction of the high-pressure hydraulic oil based on the performance to be verified of the hydraulic pump under test.

[0081] Specifically, the flow direction of the high-pressure hydraulic oil is related to the performance to be verified of the hydraulic pump under test.

[0082] S502. Apply a load to the hydraulic pump under test based on the flow direction of the high-pressure hydraulic oil, and control the hydraulic pump under test to be loaded.

[0083] Specifically, the direction of the load applied to the hydraulic pump under test is the same as the flow direction of the high-pressure hydraulic oil.

[0084] In this step, a load in the same direction as the flow direction of the high-pressure hydraulic oil is applied to the hydraulic pump under test, and the hydraulic pump under test is controlled to be loaded.

[0085] S503. Based on the performance parameters collected by the sensor during the loading process of the hydraulic pump under test, verify the performance of the hydraulic pump under test based on the performance parameters.

[0086] Specifically, there are multiple types of sensors. For example, the types of sensors can include vibration sensors, temperature sensors, pressure sensors, displacement sensors, and force sensors. The performance to be verified of the hydraulic pump under test corresponds to specific performance parameters, and these performance parameters need to be collected based on specific types of sensors.

[0087] In this step, based on the performance to be verified of the hydraulic pump under test, determine the performance parameters to be collected. Based on the sensors corresponding to the types of these performance parameters, read the performance parameters recorded on the sensors. Based on the performance verification method corresponding to the performance to be verified and the read performance parameters, verify the performance of the hydraulic pump under test.

[0088] The method of this embodiment can be used to execute Figure 1 the steps of the device embodiment shown. The specific implementation principle and process are similar, and will not be elaborated here.

[0089] For the realization process of the functions and roles of each unit in the above device, please refer to the realization process of the corresponding steps in the above method for details, and will not be elaborated here.

[0090] For the apparatus embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to the description of the method embodiments. The apparatus embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this application. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0091] The above are only the preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the scope of protection of this application.

Claims

1. A digital hydraulic pump test bench, characterized in that: The digital hydraulic pump test bench includes a driving module and a loading module; wherein the driving module includes a hydraulic pump to be tested, a DC speed regulating motor, a plurality of couplings, and a shock absorber, and is used to provide high-pressure oil to the loading module when the performance of the hydraulic pump to be tested is verified. The hydraulic pump to be tested is provided with an oil pressure port, and the oil pressure port is connected to the loading module. One end of the plurality of couplings is connected to the hydraulic pump to be tested, and the other end is connected to the DC speed regulating motor. The shock absorber is connected to the DC speed regulating motor. A plurality of sensors are installed on the hydraulic pump to be tested, and the type of the sensor is determined according to the type of the hydraulic pump to be tested and the performance to be verified. The sensor is used to collect the performance parameters of the hydraulic pump to be tested during the loading process, wherein the performance parameters are used to perform performance verification on the hydraulic pump to be tested; The oil pressure port of the tested hydraulic pump is connected to a loading module, the loading module includes a bridge circuit and a loading circuit, a plurality of the oil pressure ports are respectively connected to a first series connection point and a second series connection point of the bridge circuit, a parallel connection point of the bridge circuit is connected to the loading circuit, and the loading module is used to determine the flow direction of the high-pressure oil based on the performance to be verified of the tested hydraulic pump, apply a load to the tested hydraulic pump based on the flow direction of the high-pressure oil, and control the loading of the tested hydraulic pump; Wherein, the bridge circuit determines the flow direction of the high-pressure oil based on the performance to be verified of the tested hydraulic pump, and controls the high-pressure oil to flow to the loading circuit; the loading circuit applies a load to the tested hydraulic pump based on the flow direction of the high-pressure oil, and controls the loading of the tested hydraulic pump; the loading circuit includes a two-way logic unit, a proportional relief valve, a pressure valve cover plate, and an electromagnetic reversing seat valve; the oil inlet of the electromagnetic reversing seat valve is connected to the oil outlet of the bridge circuit; the oil outlet of the electromagnetic reversing seat valve is connected to the oil inlet of the proportional relief valve; the outlet of the proportional relief valve is connected to the oil inlet of the pressure valve cover plate; the outlet of the pressure valve cover plate is connected to the oil return port and the oil tank; the input end of the two-way logic unit is connected to the pressure valve cover plate, and the output end is connected to the proportional relief valve and the electromagnetic reversing seat valve; When the pressure of the high-pressure oil reaches the set pressure of the proportional relief valve, the overflow process begins, and a pressure difference is established at both ends of the valve core of the two-way logic unit; the valve core rises, and the high-pressure oil in the loading circuit begins to overflow at the set pressure and enters the loading condition.

2. The digital hydraulic pump test bench according to claim 1, characterized in that: The bridge circuit includes multiple one-way valves, which work together to control the bidirectional flow of the high-pressure oil; wherein the first one-way valve and the second one-way valve are connected in series, the third one-way valve and the fourth one-way valve are connected in series, the first one-way valve and the third one-way valve are connected in parallel, and the second one-way valve and the fourth one-way valve are connected in parallel.

3. The digital hydraulic pump test bench according to claim 2, characterized in that: When the tested hydraulic pump is controlled to load forward, the first one-way valve is closed, the second one-way valve is opened, and the fourth one-way valve is opened, and the high-pressure oil enters the loading circuit through the first oil inlet, the second one-way valve, and the fourth one-way valve, and flows to the oil tank through the second oil inlet; When the tested hydraulic pump is controlled to be reverse loaded, the first one-way valve is opened, the second one-way valve is closed, and the third one-way valve is opened. The high-pressure oil enters the loading circuit through the second oil inlet, the first one-way valve, and the third one-way valve, and flows to the oil tank through the first oil inlet.

4. The digital hydraulic pump test bench according to claim 1, characterized in that: The pressure valve cover plate is used to close the pressure valve and send the pressure signal collected by the low-pressure sensor to the two-way logic unit; The two-way logic unit controls the states of the proportional relief valve and the electromagnetic reversing seat valve based on the pressure signal sent by the pressure valve cover plate; The electromagnetic reversing seat valve is used to control the flow direction of the high-pressure oil, and adjusts the flow direction of the high-pressure oil based on the control of the two-way logic unit to perform loading or unloading operations; The proportional relief valve is used to adjust the pressure of the loading circuit based on the control of the two-way logic unit.

5. The digital hydraulic pump test bench according to claim 1, characterized in that: When the hydraulic pump under test is a closed circuit, the hydraulic pump test bench further includes an oil replenishing module; wherein the oil replenishing module is connected to the loading module; The oil replenishment module is used to provide low-pressure oil to the loading module when the outlet pressure of the tested hydraulic pump is lower than a preset value.

6. The digital hydraulic pump test bench according to claim 5, characterized in that: The oil replenishment module includes a DC speed regulating motor, a safety valve, a high-pressure filter, a metering pump and an oil suction filter; wherein the DC speed regulating motor is connected to the metering pump; the oil suction filter is located at the oil suction end of the metering pump; the metering pump is connected to the high-pressure filter; and the safety valve is located between the outlet of the metering pump and the oil tank.

7. The digital hydraulic pump test bench according to claim 6, characterized in that: The DC speed regulating motor starts and drives the metering pump, the metering pump sucks low-pressure oil from the oil tank through the oil suction filter, and the low-pressure oil passes through the high-pressure filter to reach the loading module; The high-pressure filter is used to remove impurities in the low-pressure oil. The safety valve is used to overflow the excess oil at the outlet of the metering pump back to the oil tank when the outlet pressure of the metering pump is higher than the preset pressure.

8. A method for verifying the control performance of a digital hydraulic pump, characterized in that: The digital hydraulic pump control performance verification method is applied to the digital hydraulic pump test bench according to any one of claims 1 to 7; the method comprises: Determine the flow direction of the high-pressure oil based on the performance to be verified of the hydraulic pump under test; Applying a load to the hydraulic pump under test based on the flow direction of the high-pressure oil, and controlling the loading of the hydraulic pump under test; The performance parameters of the hydraulic pump under test during the loading process are collected based on sensors, and the performance of the hydraulic pump under test is verified based on the performance parameters.

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