Electro-hydraulic system for oil cylinder synchronization and loading comprehensive experiment

Abstract

The utility model discloses an electro-hydraulic system for an oil cylinder synchronization and loading comprehensive experiment, which relates to a hydraulic control system and comprises a main oil way and an oil return way which are connected with an oil tank. The hydraulic cylinders are oppositely arranged; a constant-pressure variable pump is mounted on the main oil way, and a proportional overflow valve is arranged on the constant-pressure variable pump; a connecting oil way connected with the main oil way is further arranged on the oil return oil way, and an overflow valve is installed on the connecting oil way. The hydraulic system further comprises a proportional direction valve set matched with the hydraulic cylinder, a pressure oil port of the proportional direction valve set is connected with the main oil way, an oil return port of the proportional direction valve set is connected with the oil tank, and two working oil ports of the proportional direction valve set are connected with an oil inlet of the hydraulic cylinder and an oil return port of the hydraulic cylinder respectively. According to the utility model, control effects under different hydraulic oil sources, different proportional valves and different load working conditions can be compared during an experiment.

Description

Technical Field

[0001] The utility model relates to a hydraulic control system, and more specifically, to an electro-hydraulic system for comprehensive experiments on cylinder synchronization and loading. Background Art

[0002] At present, the solutions for multi-cylinder synchronous control can generally be divided into three categories: mechanical synchronization, hydraulic synchronization, and electro-hydraulic proportional (servo) synchronization. In occasions where high synchronization accuracy is required, the electro-hydraulic proportional (servo) synchronization method is often adopted. However, the control effect of the electro-hydraulic proportional (servo) synchronization system and the stability of the control system are related to many factors, such as: the type of hydraulic oil source, the type of proportional valve (servo valve), different load conditions, hydraulic oil temperature, control algorithm, etc. Due to the existence of these factors, when designing an electro-hydraulic proportional (servo) synchronization system, there are often certain difficulties in the selection of some components, the control range of some parameters, and algorithm design.

[0003] At the same time, the current solutions for the pressure control system of cylinders can generally be divided into: pressure control by relief valve, pressure control by reducing valve, pressure control by reducing and relief valve, pressure control by proportional valve (servo valve), pressure control by switching valve, etc. And the control effect of the pressure and the stability of the control system are related to many factors, such as: different hydraulic oil sources, different types of control valves, different load conditions, hydraulic oil temperature, control algorithm, etc. Due to the existence of these factors, when designing an electro-hydraulic pressure control system, there are often certain difficulties in the selection of some components, the control range of some parameters, and algorithm design.

[0004] In addition, in actual engineering design, due to reasons such as tight project schedule and limited test conditions, it is often impossible to conduct a relatively comprehensive test on the performance of the electro-hydraulic proportional (servo) synchronization control system and the electro-hydraulic pressure control system. Designing a relevant test bench can well solve this problem.

[0005] At present, there is no test bench for an electro-hydraulic proportional (servo) synchronization control system that considers different hydraulic oil sources, different types of proportional valves (servo valves), different load conditions, different hydraulic oil temperatures, and different control algorithms. Nor is there a test bench for an electro-hydraulic pressure control system that considers different hydraulic oil sources, different types of control valves, different load conditions, hydraulic oil temperature, control algorithm, etc. Summary of the Utility Model

[0006] The purpose of the utility model is to provide an electro-hydraulic system for comprehensive experiments on cylinder synchronization and loading, which can compare the control effects under different hydraulic oil sources, different proportional valves, and different load conditions during experiments.

[0007] To achieve the object of the present utility model, the technical solution adopted is: a electro-hydraulic system for comprehensive experiments of oil cylinder synchronization and loading, including a main oil circuit and a return oil circuit connected to an oil tank; also including hydraulic cylinders arranged oppositely.

[0008] A constant pressure variable pump is installed on the main oil circuit, and a proportional relief valve is equipped on the constant pressure variable pump.

[0009] A connecting oil circuit connected to the main oil circuit is further provided on the return oil circuit, and a relief valve is installed on the connecting oil circuit.

[0010] It also includes a proportional direction valve group arranged in cooperation with the hydraulic cylinders. The pressure oil port of the proportional direction valve group is connected to the main oil circuit, the return oil port of the proportional direction valve group is connected to the oil tank, and the two working oil ports of the proportional direction valve group are respectively connected to the oil inlet and the oil return port of the hydraulic cylinder.

[0011] Furthermore, the oppositely arranged hydraulic cylinders are multiple groups, and each hydraulic cylinder is provided with a proportional direction valve group in cooperation.

[0012] Furthermore, a pressure regulating oil circuit is connected in parallel between the main oil circuit and the oil inlet of the hydraulic cylinder. A proportional pressure reducing relief valve is installed on the pressure regulating oil circuit of one group of hydraulic cylinders, and a pressure reducing relief valve is installed on the pressure regulating oil circuits of the remaining hydraulic cylinders.

[0013] Furthermore, an unloading oil circuit is connected in parallel between the working oil port of the proportional direction valve group and the oil return port of the hydraulic cylinder, and high-pressure stop valves are installed at the outlet end of the pressure reducing relief valve, the outlet end of the proportional pressure reducing relief valve, between the working oil port of the proportional direction valve group and the oil inlet of the hydraulic cylinder, and on the unloading oil circuit.

[0014] Furthermore, an oil suction filter, an oil suction stop valve, and a shock absorber are also installed at the inlet end of the constant pressure variable pump, and a high-pressure filter is installed at the outlet end of the constant pressure variable pump.

[0015] Furthermore, an oil return filter, a cooler, and a solenoid valve are also installed on the return oil circuit.

[0016] Furthermore, an air filter, a liquid level gauge, a thermometer, and a heater are also installed on the oil tank.

[0017] Furthermore, it also includes a human-machine interaction unit and a control unit. The human-machine interaction unit is electrically connected to the control unit, and the control unit controls the proportional relief valve, the constant pressure variable pump, the solenoid valve, the heater, the cooler, the first proportional direction valve group, the proportional pressure reducing relief valve, and the second proportional direction valve group respectively.

[0018] The beneficial effects of the present utility model are:

[0019] 1. When the present utility model is used for experiments on a multi-cylinder synchronous control system, it can conduct a load-bearing experimental verification on the pressure control system of the cylinder in advance, so that the pressure control system of the cylinder is not restricted by time and site. At the same time, the present utility model can simulate various load conditions, especially those that are difficult to encounter during the actual equipment debugging process but may occur during the actual use of the equipment, so as to verify whether the proportional valve-controlled cylinder system solution meets the design requirements and provide a reference for the optimal design of the hydraulic system.

[0020] 2. When the present utility model is used for experiments on a multi-cylinder synchronous control system, it can test the hydraulic systems designed with different proportional valve-controlled cylinders, so as to test the synchronous accuracy, positioning control accuracy, and speed of the two proportional valve-controlled cylinder hydraulic systems.

[0021] 3. When the present utility model is used for experiments on a multi-cylinder synchronous control system and experiments on the cylinder pressure control system, it can provide two hydraulic oil sources, one of which is a "constant displacement pump + relief valve", and the other is a "constant pressure variable pump", so as to test whether there are differences in the influence of the hydraulic oil source on the pressure control effect of the designed proportional pressure control system.

[0022] 4. When the present utility model is used for experiments on a multi-cylinder synchronous control system and experiments on the cylinder pressure control system, it can test the influence of the hydraulic oil temperature on the pressure control effect of the proportional pressure control system, and can debug the pressure control effect of the proportional pressure control system in combination with the pressure control algorithm, saving the time cost required for debugging and reducing the accidental risks during the debugging process. At the same time, when the present utility model is used for experiments on the cylinder pressure control system, it can test the influence of variable load conditions on the pressure control effect of the proportional pressure control system. Description of the Drawings

[0023] The drawings illustrate exemplary embodiments of the present utility model and are used together with the description to explain the principles of the present utility model. These drawings are included to provide a further understanding of the present utility model, and the drawings are included in this specification and form a part of this specification.

[0024] Figure 1 is the hydraulic system diagram of the electro-hydraulic system for the comprehensive experiment of cylinder synchronization and loading;

[0025] Figure 2 is the electrical control system diagram of the electro-hydraulic system for the comprehensive experiment of cylinder synchronization and loading.

[0026] Marks in the drawings and corresponding component names:

[0027] 1. Air filter, 2. Liquid level gauge, 3. Suction oil filter, 4. Suction oil stop valve, 5. Shock absorber hose, 6. Thermometer, 7. Heater, 8. Low-pressure stop valve, 9. Return oil filter, 10. Cooler, 11. Constant pressure variable pump, 12. High-pressure filter, 13. Proportional relief valve, 14. Solenoid valve, 15. Relief valve, 16.1 - 16.4 Proportional direction valve group one, 17.1 - 17.24 High-pressure stop valve, 18.1 - 18.9 Pressure gauge, 19.1 - 19.6 Pressure reducing relief valve, 20.1, 20.2 Proportional pressure reducing relief valve, 21.1 - 21.3 Pressure sensor, 22.1 - 22.4 Proportional direction valve group two, 23.1 - 23.4, 26.1 - 26.4 Displacement sensor, 24.1 - 24.4 Hydraulic cylinder one, 25.1 - 25.4 Hydraulic cylinder two, 26. Main oil circuit, 27. Return oil circuit, 28. Pressure regulating oil circuit, 29. Unloading oil circuit, 30. Connecting oil circuit, 31. Oil tank. Detailed implementation mode

[0028] The present utility model will be further described in detail below in conjunction with the drawings and the implementation mode. It can be understood that the specific implementation mode described here is only used to explain the relevant content and does not limit the present utility model. In addition, it should be noted that for the convenience of description, only the parts related to the present utility model are shown in the drawings.

[0029] It should be noted that, without conflict, the implementation modes and the features in the implementation modes of the present utility model can be combined with each other. The present utility model will be described in detail below with reference to the drawings and in conjunction with the implementation mode.

[0030] As Figure 1 shown, an electro-hydraulic system for comprehensive experiments on oil cylinder synchronization and loading provided by the present utility model includes an oil tank 31. A low-pressure stop valve 8 is installed at the oil discharge port of the oil tank 31, and a main oil circuit 26 and a return oil circuit 27 are also connected to the oil tank 31. The main oil circuit 26 provides hydraulic oil for the actuating element, and the return oil circuit 27 is used to return the hydraulic oil to the oil tank 31. It also includes four groups of hydraulic cylinders. Each group includes a pair of relatively arranged hydraulic cylinder one and hydraulic cylinder two. That is, the four hydraulic cylinder ones in the present invention are respectively hydraulic cylinder one 24.1, hydraulic cylinder one 24.2, hydraulic cylinder one 24.3, and hydraulic cylinder one 24.4, and the four hydraulic cylinder twos are respectively hydraulic cylinder two 25.1, hydraulic cylinder two 25.2, hydraulic cylinder two 25.3, and hydraulic cylinder two 25.4. Among them, hydraulic cylinder one 24.1 is arranged opposite to hydraulic cylinder two 25.1, hydraulic cylinder one 24.2 is arranged opposite to hydraulic cylinder two 25.2, hydraulic cylinder one 24.3 is arranged opposite to hydraulic cylinder two 25.3, and hydraulic cylinder one 24.4 is arranged opposite to hydraulic cylinder two 25.4.

[0031] The main oil circuit 26 is also equipped with a constant pressure variable pump 11. The constant pressure variable pump 11 pumps the hydraulic oil in the oil tank 31 to provide hydraulic oil for the hydraulic system. At the same time, a proportional overflow valve 13 is also arranged on the constant pressure variable pump 11, and the overflow oil port of the proportional overflow valve 13 is connected to the oil tank 31. A connecting oil circuit 30 is also connected between the oil return circuit 27 and the main oil circuit 26, and an overflow valve 15 is also installed on the connecting oil circuit 30.

[0032] The electro-hydraulic system for the comprehensive experiment of oil cylinder synchronization and loading also includes a proportional direction valve group arranged in cooperation with the hydraulic cylinders. Among them, proportional direction valve group 16.1 is arranged for hydraulic cylinder 24.1, proportional direction valve group 16.2 is arranged for hydraulic cylinder 24.2, proportional direction valve group 16.3 is arranged for hydraulic cylinder 24.3, proportional direction valve group 16.4 is arranged for hydraulic cylinder 24.4, proportional direction valve group 22.1 is arranged for hydraulic cylinder 25.1, proportional direction valve group 22.2 is arranged for hydraulic cylinder 25.2, proportional direction valve group 22.3 is arranged for hydraulic cylinder 25.3, and proportional direction valve group 22.4 is arranged for hydraulic cylinder 25.4. The pressure oil ports of proportional direction valve group 16.1, proportional direction valve group 16.2, proportional direction valve group 16.3, proportional direction valve group 16.4, proportional direction valve group 22.1, proportional direction valve group 22.2, proportional direction valve group 22.3, and proportional direction valve group 22.4 are all connected to the main oil circuit 26, so that the hydraulic oil transported by the constant pressure variable pump 11 can enter proportional direction valve group 16.1, proportional direction valve group 16.2, proportional direction valve group 16.3, proportional direction valve group 16.4, proportional direction valve group 22.1, proportional direction valve group 22.2, proportional direction valve group 22.3, and proportional direction valve group 22.4 through the main oil circuit 26. The two working oil ports of proportional direction valve group 16.1 are respectively connected to the oil inlet and the oil return port of hydraulic cylinder 24.1, the two working oil ports of proportional direction valve group 16.2 are respectively connected to the oil inlet and the oil return port of hydraulic cylinder 24.3, the two working oil ports of proportional direction valve group 16.3 are respectively connected to the oil inlet and the oil return port of hydraulic cylinder 24.3, the two working oil ports of proportional direction valve group 16.4 are respectively connected to the oil inlet and the oil return port of hydraulic cylinder 24.4, the two working oil ports of proportional direction valve group 22.1 are respectively connected to the oil inlet and the oil return port of hydraulic cylinder 25.1, the two working oil ports of proportional direction valve group 22.2 are respectively connected to the oil inlet and the oil return port of hydraulic cylinder 25.2, the two working oil ports of proportional direction valve group 22.3 are respectively connected to the oil inlet and the oil return port of hydraulic cylinder 25.3, and the two working oil ports of proportional direction valve group 22.4 are respectively connected to the oil inlet and the oil return port of hydraulic cylinder 25.4. The oil return ports of proportional direction valve group 16.1, proportional direction valve group 16.2, proportional direction valve group 16.3, proportional direction valve group 16.4, proportional direction valve group 22.1, proportional direction valve group 22.2, proportional direction valve group 22.3, and proportional direction valve group 22.4 are all connected to the fuel tank 33 through the oil return oil circuit 27.

[0033] Here, it should be noted that, as required, the first proportional direction valve group and the second proportional direction valve group can be the same proportional direction valve group, or they can be different proportional direction valve groups. In the present utility model, the first proportional direction valve group and the second proportional direction valve group are selected as different proportional direction valve groups. In this electro-hydraulic system, the oil inlet of the first hydraulic cylinder is the oil port on the first hydraulic cylinder that communicates with the rodless cavity of the first hydraulic cylinder, and the oil return port of the first hydraulic cylinder is the oil port on the first hydraulic cylinder that communicates with the rod chamber of the first hydraulic cylinder; the oil inlet of the second hydraulic cylinder is the oil port on the second hydraulic cylinder that communicates with the rodless cavity of the second hydraulic cylinder, and the oil return port of the second hydraulic cylinder is the oil port on the second hydraulic cylinder that communicates with the rod chamber of the second hydraulic cylinder.

[0034] As a further option of this embodiment, a pressure regulating oil circuit 28 is connected in parallel between the main oil circuit 26 and the oil inlets of the first hydraulic cylinders 24.1, 24.2, 24.3, 24.4, the second hydraulic cylinders 25.1, 25.2, 25.3, 25.4; a proportional pressure reducing and overflow valve 20.1 is installed on the pressure regulating oil circuit 28 between the main oil circuit 26 and the oil inlet of the first hydraulic cylinder 24.1, and a proportional pressure reducing and overflow valve 20.2 is installed on the pressure regulating oil circuit 28 between the main oil circuit 26 and the oil inlet of the second hydraulic cylinder 25.1. Pressure reducing and overflow valves are installed on the pressure regulating oil circuits 28 between the main oil circuit 26 and the oil inlets of the first hydraulic cylinders 24.2, 24.3, 24.4, between the main oil circuit 26 and the oil inlets of the second hydraulic cylinders 25.2, 25.3, 25.4. That is, there are a total of 8 pressure regulating oil circuits in this electro-hydraulic system, among which proportional pressure reducing and overflow valves are installed on 2 pressure regulating oil circuits, and the proportional pressure reducing and overflow valves installed on these 2 pressure regulating oil circuits are the proportional pressure reducing and overflow valve 20.1 and the proportional pressure reducing and overflow valve 20.2 respectively. Pressure reducing and overflow valves are installed on the other 6 pressure regulating oil circuits, and the 6 pressure reducing and overflow valves are the pressure reducing and overflow valve 19.1, the pressure reducing and overflow valve 19.2, the pressure reducing and overflow valve 19.3, the pressure reducing and overflow valve 19.4, the pressure reducing and overflow valve 19.5, and the pressure reducing and overflow valve 19.6 respectively.

[0035] As a further option of this embodiment, in order to facilitate the control of the pressure regulating oil circuit 28, high-pressure cut-off valves are installed at the outlet ends of each pressure reducing and overflow valve and each proportional pressure reducing and overflow valve. These high-pressure cut-off valves are the high-pressure cut-off valves 17.5, 17.7, 17.9, 17.11, 17.14, 17.17, 17.20, 17.24 respectively.

[0036] As a further option of this embodiment, high-pressure cut-off valves are also installed between the working oil ports of each proportional direction valve group 1 and the oil inlet ports of each hydraulic cylinder 1, and between the working oil ports of each proportional direction valve group 2 and the oil inlet ports of each hydraulic cylinder 2. These high-pressure cut-off valves are respectively high-pressure cut-off valve 17.1, high-pressure cut-off valve 17.2, high-pressure cut-off valve 17.3, high-pressure cut-off valve 17.4, high-pressure cut-off valve 17.15, high-pressure cut-off valve 17.18, high-pressure cut-off valve 17.21, and high-pressure cut-off valve 17.23.

[0037] As a further option of this embodiment, unloading oil circuits 29 are connected in parallel between the working oil ports of each proportional direction valve group 1 and the oil return ports of the corresponding hydraulic cylinder 1, and between the working oil ports of each proportional direction valve group 2 and the oil return ports of the corresponding hydraulic cylinder 2. High-pressure cut-off valves are also installed on these unloading oil circuits 29. These high-pressure cut-off valves are respectively high-pressure cut-off valve 17.6, high-pressure cut-off valve 17.8, high-pressure cut-off valve 17.10, high-pressure cut-off valve 17.12, high-pressure cut-off valve 17.13, high-pressure cut-off valve 17.16, high-pressure cut-off valve 17.19, and high-pressure cut-off valve 17.22.

[0038] As a further option of this embodiment, an oil suction filter 3, an oil suction shut-off valve 4, and a shock absorber hose 5 are also installed at the inlet end of the constant-pressure variable pump 11. Specifically, the oil suction filter 3 is installed at the inlet end of the main oil circuit 26, the shock absorber hose 5 is installed at the inlet end of the constant-pressure variable pump 11, the oil suction shut-off valve 4 is installed between the oil suction filter 3 and the shock absorber hose 5, and the oil suction filter 3 is used to filter the hydraulic oil entering the main oil circuit 26. The shock absorber hose 5 can prevent the vibration generated during the operation of the constant-pressure variable pump 11 from being transmitted to the fuel tank 31, and the oil suction shut-off valve 4 controls the cut-off and connection of the main oil circuit 26. A high-pressure filter 12 is also installed at the outlet end of the constant-pressure variable pump 11. The high-pressure filter 12 performs secondary filtration on the hydraulic oil sent out by the constant-pressure variable pump 11 to prevent the operation of subsequent actuators from being affected due to impurities in the hydraulic oil sent out by the constant-pressure variable pump 11.

[0039] As a further option of this embodiment, an oil return filter 9, a cooler 10, and a solenoid valve 14 are also installed on the oil return oil circuit 27. The oil return filter 9 filters the hydraulic oil flowing back to the fuel tank 31, the cooler 10 is used to cool the hydraulic oil flowing back to the fuel tank 31, and the solenoid valve 14 is used to control the cut-off and connection of the oil return oil circuit 27.

[0040] As a further option of this embodiment, an air filter 1, a liquid level gauge 2, a thermometer 6, and a heater 7 are also installed on the fuel tank 31. The liquid level gauge 2 is used to detect the liquid level height of the hydraulic oil in the fuel tank 31, the thermometer 6 is used to detect the temperature of the hydraulic oil in the fuel tank 31, and the heater 7 is used to heat the hydraulic oil in the fuel tank 31.

[0041] As a further option in this embodiment, in order to facilitate monitoring the hydraulic oil pressure of the main oil circuit 26, the oil inlet of each first hydraulic cylinder, and the oil inlet of each second hydraulic cylinder, pressure gauges are installed on the main oil circuit 26, between the oil inlet of each first hydraulic cylinder and the main oil circuit 26, and between the oil inlet of each second hydraulic cylinder and the main oil circuit 26. These pressure gauges are respectively pressure gauges 18.1, 18.2, 18.3, 18.4, 18.5, 18.6, 18.7, 18.8, 18.9; at the same time, pressure sensors are installed on the main oil circuit 26, between the proportional pressure reducing overflow valve 20.1 and the oil inlet of the first hydraulic cylinder 24.1, and between the proportional pressure reducing overflow valve 20.2 and the oil inlet of the second hydraulic cylinder 25.1. These pressure sensors are respectively pressure sensors 21.2, 21.1, 21.3. In addition, displacement sensors 23.1 are provided on the first hydraulic cylinder 24.1, displacement sensors 23.2 are provided on the first hydraulic cylinder 24.2, displacement sensors 23.3 are provided on the first hydraulic cylinder 24.3, displacement sensors 23.4 are provided on the first hydraulic cylinder 24.4, displacement sensors 26.1 are provided on the second hydraulic cylinder 25.1, displacement sensors 26.2 are provided on the second hydraulic cylinder 25.2, displacement sensors 26.3 are provided on the second hydraulic cylinder 25.3, and displacement sensors 26.4 are provided on the second hydraulic cylinder 25.4.

[0042] As a further option in this embodiment, as Figure 2 shown, this electro-hydraulic system further includes a human-machine interaction unit and a control unit. Among them, the human-machine interaction unit includes buttons and a human-machine interface. The control unit is a PLC, and the output end of the button is electrically connected to the input end of the PLC, and the human-machine interface is bidirectionally electrically connected to the PLC; the output end of the PLC is also connected to an indicator light and a buzzer, so that the PLC can control the indicator light and the buzzer to give an alarm prompt.

[0043] The output end of the PLC is respectively electrically connected to the input ends of the proportional overflow valve 13, the constant pressure variable pump 11, the solenoid valve 14, the heater 7, the cooler 10, the proportional direction valve group 16.1-16.4, the proportional pressure reducing overflow valves 20.1, 20.2, and the proportional direction valve group 22.1-22.4, so that the PLC respectively controls the proportional overflow valve 13, the constant pressure variable pump 11, the solenoid valve 14, the heater 7, the cooler 10, the proportional direction valve group 16.1-16.4, the proportional pressure reducing overflow valves 20.1, 20.2, and the proportional direction valve group 22.1-22.4.

[0044] Since there are many electrical components in this electro-hydraulic system, for the convenience of control, in addition to being connected to the above-mentioned actuators, the output end of the PLC can also be electrically connected to the remaining electrically actuated components in this electro-hydraulic system.

[0045] When this electro-hydraulic system is used to detect the related functions of a multi-cylinder synchronous control system:

[0046] 1. Implementation of two hydraulic oil sources: The two hydraulic oil sources are respectively the "fixed-displacement pump + relief valve" hydraulic oil source and the "constant-pressure variable pump" hydraulic oil source.

[0047] Set the set pressure of the relief valve 15 slightly higher than the system rated pressure; fix the setting value of the proportional relief valve 13 at a relatively high value so that the constant-pressure setting value of the constant-pressure variable pump 11 is slightly higher than the set pressure of the relief valve 15. In this way, the displacement of the constant-pressure variable pump 11 is always at the maximum displacement, and the hydraulic oil source at this time is the "fixed-displacement pump + relief valve" hydraulic oil source.

[0048] Set the set pressure of the relief valve 15 slightly higher than the system rated pressure; set the setting value of the proportional relief valve 13 to a value within a certain range so that the constant-pressure setting value of the constant-pressure variable pump 11 takes different setting values according to experimental needs, but the maximum setting value does not exceed the system rated pressure. In this way, the actual system pressure reaches the constant-pressure setting value of the constant-pressure variable pump 11, and the displacement of the constant-pressure variable pump 11 is at a relatively small displacement to maintain the system pressure at the constant-pressure setting value of the constant-pressure variable pump 11. The hydraulic oil source at this time is the "constant-pressure variable pump" hydraulic oil source.

[0049] 2. Implementation of two proportional valve-controlled cylinder systems:

[0050] One proportional valve-controlled cylinder system: It consists of the proportional direction valve group 16.1, the hydraulic cylinder 24.1, and the displacement sensor 23.1. At this time, the synchronous test of the hydraulic cylinders 24.2, 24.3, and 24.4 can be carried out. For the convenience of description, it is named the proportional valve-controlled cylinder system 1. At this time, the high-pressure cut-off valves 17.1, 17.2, 17.3, and 17.4 are in the open state, and the high-pressure cut-off valves 17.5, 17.6, 17.7, 17.8, 17.9, 17.10, 17.11, and 17.12 are in the closed state.

[0051] Another proportional valve-controlled cylinder system: It consists of the second proportional direction valve group 22.1, the second hydraulic cylinder 25.1, and the displacement sensor 26.1. At this time, the synchronous test of the second hydraulic cylinders 25.2, 25.3, and 25.4 can be carried out, and for the convenience of description, it is named the second proportional valve-controlled cylinder system. At this time, the high-pressure stop valves 17.15, 17.18, 17.21, and 17.23 are in the open state, and the high-pressure stop valves 17.13, 17.14, 17.16, 17.17, 17.19, 17.20, 17.22, and 17.24 are in the closed state.

[0052] 3. Implementation of the proportional valve-controlled cylinder system under different load conditions:

[0053] When it is necessary to load the first hydraulic cylinders 24.1, 24.2, 24.3, and 24.4 in the first proportional valve-controlled cylinder system, the second hydraulic cylinders 25.1, 25.2, 25.3, and 25.4 in the second proportional valve-controlled cylinder system are used to load them respectively. The loading force magnitudes of the first hydraulic cylinders 24.1, 24.2, 24.3, and 24.4 in the first proportional valve-controlled cylinder system are adjusted by the corresponding proportional pressure-reducing overflow valves 20.2, pressure-reducing overflow valve 19.4, pressure-reducing overflow valve 19.5, and pressure-reducing overflow valve 19.6 of the second hydraulic cylinders 25.1, 25.2, 25.3, and 25.4 in the second proportional valve-controlled cylinder system. At this time, the high-pressure stop valves 17.13, 17.14, 17.16, 17.17, 17.19, 17.20, 17.22, and 17.24 are in the open state, and the high-pressure stop valves 17.15, 17.18, 17.21, and 17.23 are in the closed state.

[0054] When it is necessary to load the hydraulic cylinders 25.1, 25.2, 25.3, and 25.4 in the proportional valve-controlled cylinder system II, they are loaded respectively by the hydraulic cylinders 24.1, 24.2, 24.3, and 24.4 in the proportional valve-controlled cylinder system I. The magnitudes of the loading forces of the hydraulic cylinders 25.1, 25.2, 25.3, and 25.4 in the proportional valve-controlled cylinder system II are adjusted respectively by the proportional pressure-reducing overflow valves 20.1, pressure-reducing overflow valve 19.3, pressure-reducing overflow valve 19.2, and pressure-reducing overflow valve 19.1 corresponding to the hydraulic cylinders 24.1, 24.2, 24.3, and 24.4 in the proportional valve-controlled cylinder system I. At this time, the high-pressure stop valves 17.5, 17.6, 17.7, 17.8, 17.9, 17.10, 17.11, and 17.12 are in the open state, and the high-pressure stop valves 17.1, 17.2, 17.3, and 17.4 are in the closed state.

[0055] 4. Realization of hydraulic oil temperature regulation: The heater 7 and the cooler 10 are relied on to heat and cool the hydraulic oil respectively, so as to achieve the purpose of regulating the hydraulic oil temperature.

[0056] When this electro-hydraulic system is used for detecting the oil cylinder pressure control system:

[0057] 1. Realization of two kinds of hydraulic oil sources: The two kinds of hydraulic oil sources are respectively the "fixed displacement pump + overflow valve" hydraulic oil source and the "constant pressure variable displacement pump" hydraulic oil source.

[0058] Set the set pressure of the overflow valve 15 slightly higher than the system rated pressure; fix the adjustment value of the proportional overflow valve 13 at a relatively high value, so that the constant pressure setting value of the constant pressure variable displacement pump 11 is slightly higher than the set pressure of the overflow valve 15. In this way, the displacement of the constant pressure variable displacement pump 11 is always at the maximum displacement, and the hydraulic oil source at this time is the "fixed displacement pump + overflow valve" hydraulic oil source.

[0059] Set the set pressure of the overflow valve 15 slightly higher than the system rated pressure; set the adjustment value of the proportional overflow valve 13 to a value within a certain range, so that the constant pressure setting value of the constant pressure variable displacement pump 11 takes different set values according to the experimental needs, but the maximum set value does not exceed the rated pressure of the system. In this way, the actual pressure of the system reaches the constant pressure setting value of the constant pressure variable displacement pump 11, and the displacement of the constant pressure variable displacement pump 11 is in a relatively small displacement to maintain the system pressure at the constant pressure setting value of the constant pressure variable displacement pump 11. The hydraulic oil source at this time is the "constant pressure variable displacement pump" hydraulic oil source.

[0060] 2. Realization of the proportional pressure system under different load conditions:

[0061] A proportional pressure control system: It consists of a proportional pressure reducing and overflow valve 20.1, a pressure sensor 21.1, and a first hydraulic cylinder 24.1. For the convenience of description, it is named the first proportional pressure control system. At this time, the high-pressure cut-off valves 17.11 and 17.12 are in the open state, and the high-pressure cut-off valve 17.4 is in the closed state.

[0062] Another proportional pressure control system: It consists of a proportional pressure reducing and overflow valve 20.2, a pressure sensor 21.3, and a second hydraulic cylinder 25.1. For the convenience of description, it is named the second proportional pressure control system. At this time, the high-pressure cut-off valves 17.13 and 17.1 are in the open state, and the high-pressure cut-off valve 17.5 is in the closed state.

[0063] When loading the first proportional pressure control system, there are two loading methods: one is pressure loading, and the adjustment of the loading pressure magnitude is carried out through the proportional pressure reducing and overflow valve 20.2 in the second proportional pressure control system; the other is displacement loading, and displacement control is carried out through the second hydraulic cylinder 25.1 in the second proportional valve-controlled cylinder system, so as to achieve displacement loading.

[0064] When loading the second proportional pressure control system, there are two loading methods: one is pressure loading, and the adjustment of the loading pressure magnitude is carried out through the proportional pressure reducing and overflow valve 20.1 in the first proportional pressure control system; the other is displacement loading, and displacement control is carried out through the first hydraulic cylinder 24.1 in the first proportional valve-controlled cylinder system, so as to achieve displacement loading.

[0065] 3. Realization of hydraulic oil temperature regulation: Rely on the heater 7 and the cooler 10 to respectively realize the heating and cooling of the hydraulic oil, so as to achieve the purpose of regulating the hydraulic oil temperature.

[0066] In the description of this specification, the description with reference to terms such as "one embodiment / way", "some embodiments / ways", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with that embodiment / way or example are included in at least one embodiment / way or example of this application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment / way or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments / ways or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments / ways or examples described in this specification and the features of different embodiments / ways or examples.

[0067] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0068] Those skilled in the art should understand that the above-described embodiments are merely for clearly illustrating the present utility model and are not intended to limit the scope of the present utility model. For those skilled in the art, other changes or modifications can be made based on the above disclosure, and these changes or modifications are still within the scope of the present utility model.

Claims

1. An electro-hydraulic system for comprehensive experiments on oil cylinder synchronization and loading, characterized in that: It includes a main oil circuit and an oil return circuit connected to the oil tank; and also includes hydraulic cylinders arranged opposite to each other; A constant pressure variable pump is installed in the main oil circuit, and a proportional relief valve is provided on the constant pressure variable pump; The oil return oil circuit is also provided with a connecting oil circuit connected to the main oil circuit, and a relief valve is installed on the connecting oil circuit; It also includes a proportional directional valve group arranged in conjunction with the hydraulic cylinder, the pressure oil port of the proportional directional valve group is connected to the main oil circuit, the oil return port of the proportional directional valve group is connected to the oil tank, and the two working oil ports of the proportional directional valve group are respectively connected to the oil inlet and oil return ports of the hydraulic cylinder.

2. The electro-hydraulic system for comprehensive experiment of oil cylinder synchronization and loading according to claim 1 is characterized in that: There are multiple groups of hydraulic cylinders arranged relatively to each other, and each hydraulic cylinder is equipped with a proportional directional valve group.

3. The electro-hydraulic system for comprehensive experiment of oil cylinder synchronization and loading according to claim 2 is characterized in that: A pressure regulating oil circuit is connected in parallel between the main oil circuit and the oil inlet of the hydraulic cylinder. A proportional pressure reducing relief valve is installed on the pressure regulating oil circuit equipped with one group of hydraulic cylinders, and a pressure reducing relief valve is installed on the pressure regulating oil circuits equipped with the remaining hydraulic cylinders.

4. The electro-hydraulic system for comprehensive experiment of oil cylinder synchronization and loading according to claim 3 is characterized in that: An unloading oil circuit is connected in parallel between the working oil port of the proportional directional valve group and the oil return port of the hydraulic cylinder, and high-pressure stop valves are installed at the outlet end of the pressure reducing relief valve, the outlet end of the proportional pressure reducing relief valve, between the working oil port of the proportional directional valve group and the oil inlet of the hydraulic cylinder, and on the unloading oil circuit.

5. The electro-hydraulic system for comprehensive experiment of oil cylinder synchronization and loading according to claim 1 is characterized in that: The inlet end of the constant pressure variable pump is also equipped with an oil suction filter, an oil suction cut-off valve, and a shock-absorbing throat, and the outlet end of the constant pressure variable pump is also equipped with a high-pressure filter.

6. The electro-hydraulic system for comprehensive experiment of oil cylinder synchronization and loading according to claim 1, characterized in that: The oil return line is also equipped with an oil return filter, a cooler and a solenoid valve.

7. The electro-hydraulic system for comprehensive experiment of oil cylinder synchronization and loading according to claim 1 is characterized in that: An air filter, a liquid level gauge, a thermometer and a heater are also installed on the oil tank.

8. The electro-hydraulic system for comprehensive experiment of cylinder synchronization and loading according to any one of claims 1 to 7, characterized in that: It also includes a human-machine interaction unit and a control unit. The human-machine interaction unit is electrically connected to the control unit. The control unit controls the proportional relief valve, the constant pressure variable pump, the solenoid valve, the heater, the cooler, the proportional directional valve group, and the proportional pressure reducing relief valve respectively.

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