Synchronous loading test system for digital hydraulic cylinder of cylindrical valve

Abstract

The invention discloses a synchronous loading test system for digital hydraulic cylinders of a cylindrical valve, and relates to the technical field of digital cylinder testing, the synchronous loading test system comprises a control unit, a power source unit, a loading unit, a tested unit, a test board and a displacement sensor, the tested unit comprises six sets of tested digital hydraulic cylinders, the loading unit comprises six sets of loading hydraulic cylinders and six sets of loading assemblies, a piston rod of each tested digital hydraulic cylinder is fixedly connected with a piston rod of each loading hydraulic cylinder; the displacement sensors are arranged on the loading hydraulic cylinders; the power source unit provides high-pressure oil for the loading unit and the tested unit. The control unit is connected with the power source unit, the loading unit, the tested unit and the displacement sensor. The system can respectively provide different external loads for a plurality of digital hydraulic cylinders, so that the synchronism of the plurality of digital hydraulic cylinders under different loads can be tested and judged, the synchronous test requirements of the digital hydraulic cylinders of the cylindrical valve are met, the control precision of the cylindrical valve is improved, and the test efficiency is improved. And the technical problem that multiple sets of digital hydraulic cylinders are not suitable for synchronous testing in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of digital hydraulic cylinder testing, and particularly relates to a synchronous loading test system for a cylindrical valve digital hydraulic cylinder. Background Art

[0002] The cylindrical valve is an important component of a water turbine, mainly used to control water flow and protect the unit. By efficiently intercepting flow, protecting equipment, and optimizing hydraulic performance, it can significantly improve the reliability and economy of the water turbine unit, especially suitable for power stations that require rapid response or have poor water quality conditions, and is one of the key technologies in modern hydropower projects.

[0003] The digital hydraulic cylinder, as the main control mechanism of the cylindrical valve, mainly consists of a digital control valve, a servo hydraulic cylinder, sensors, a controller, etc. The servo hydraulic cylinder, as an actuator, can drive the opening and closing of the cylindrical valve through the telescopic movement of the piston rod. The cylindrical valve is usually controlled by six sets of digital hydraulic cylinders in cooperation, and through the cooperation of the six sets of digital hydraulic cylinders, the flow regulation requirements under different working conditions can be met.

[0004] However, the operating conditions of the cylindrical valve are complex. In complex operating conditions, the most important thing is to keep the six sets of digital hydraulic cylinders synchronized, otherwise it will affect the reliability and stability of the cylindrical valve. Therefore, before installing the digital cylinders on the cylindrical valve, it is necessary to conduct performance tests on the digital hydraulic cylinders.

[0005] The patent document with the publication number CN2262133Y proposes a testing technology for a hydraulic cylinder test bench. However, through careful analysis, it is found that due to the large volume of the cylindrical valve and the need for synchronous control of multiple sets of digital hydraulic cylinders, this existing technology is not suitable for simultaneously conducting performance tests on multiple sets of digital hydraulic cylinders. Therefore, to ensure the operating reliability and control accuracy of the cylindrical valve, it is necessary to propose a new testing technology to solve the aforementioned technical problems. Summary of the Invention

[0006] To overcome the above problems existing in the prior art, the present invention provides a synchronous loading test system for a cylindrical valve digital hydraulic cylinder. This system can respectively provide different external loads for multiple sets of digital hydraulic cylinders, so as to test the synchronism of multiple sets of digital hydraulic cylinders under different loads, which not only meets the synchronous testing requirements of the cylindrical valve digital hydraulic cylinder, improves the control accuracy of the cylindrical valve, but also solves the technical problem that there is no suitable technology for synchronously testing multiple sets of digital hydraulic cylinders in the prior art.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows: A digital hydraulic cylinder synchronous loading test system for a cylindrical valve, comprising a control unit, a power source unit, a loading unit, a unit under test, a test bench and displacement sensors. The power source unit includes oil station one and oil station two. The unit under test includes six digital hydraulic cylinders under test. The loading unit includes six loading hydraulic cylinders and six loading assemblies. The digital hydraulic cylinders under test are respectively fixed above the test bench, and the loading hydraulic cylinders are respectively fixed below the test bench. The piston rods of the respective digital hydraulic cylinders under test are fixedly connected to the piston rods of the respective loading hydraulic cylinders. The displacement sensors are respectively arranged on the respective loading hydraulic cylinders for detecting the displacement output of the piston rods of the digital hydraulic cylinders under test. Oil station one supplies high-pressure oil to the respective digital hydraulic cylinders under test, and oil station two supplies high-pressure oil to the respective loading hydraulic cylinders through the loading assemblies. The control unit is respectively connected to the power source unit, the loading unit, the unit under test and the displacement sensors, and is used for respectively providing different external loads for the respective digital hydraulic cylinders under test through the power source unit and the loading unit, obtaining the displacements of the respective digital hydraulic cylinders under test under different loads according to the displacement outputs detected by the respective displacement sensors, and judging the synchronism of the respective digital hydraulic cylinders under test. The digital hydraulic cylinders under test and the loading hydraulic cylinders are both fixedly arranged in a straight line on the test bench.

[0008] The loading assembly includes a first switching valve, an electromagnetic directional valve, a one-way self-compensating oil supply assembly, a load regulating assembly, a force sensor, a hydraulic control locking valve group A and a hydraulic control locking valve group B. The piston rod of the loading hydraulic cylinder is fixedly connected to the piston rod of the digital hydraulic cylinder under test through a hinge. The force sensor is fixed between the loading hydraulic cylinder and the piston rod of the digital hydraulic cylinder under test and is connected to the control unit for detecting the load of the digital hydraulic cylinder under test. The oil inlet P of the electromagnetic directional valve is connected to the oil pump through the first switching valve. The working oil ports A and B of the electromagnetic directional valve are respectively connected to the rodless cavity and the rod cavity of the loading hydraulic cylinder through the hydraulic control locking valve group A and the hydraulic control locking valve group B. The one-way self-compensating oil supply assembly and the load regulating assembly are connected in parallel between the hydraulic control locking valve group A and the hydraulic control locking valve group B, and the one-way self-compensating oil supply assembly and the load regulating assembly cooperate to regulate the loading pressure of the loading hydraulic cylinder.

[0009] The hydraulic control locking valve group A includes a hydraulic control check valve A and a second switching valve A, and the hydraulic control locking valve group B includes a hydraulic control check valve B and a second switching valve B. The hydraulic control check valve A and the second switching valve A are sequentially connected between the working oil port A and the rodless cavity, and the hydraulic control check valve B and the second switching valve B are sequentially connected between the working oil port B and the rod cavity. The control cavity of the hydraulic control check valve A is communicated with the working oil port B, and the control cavity of the hydraulic control check valve B is communicated with the working oil port A.

[0010] The load adjustment component includes a proportional valve, a first one-way valve, and a second one-way valve. The oil inlet of the first one-way valve is connected between the hydraulic control one-way valve A and the second switching valve A. The oil inlet of the second one-way valve is connected between the hydraulic control one-way valve B and the second switching valve B. The oil outlets of the first one-way valve and the second one-way valve are both connected to the oil tank of oil station two through the proportional valve. The proportional valve is connected to the control unit, and the control unit adjusts the loading pressure by adjusting the set pressure of the proportional valve.

[0011] The one-way self-compensating oil supply component includes a third one-way valve and a fourth one-way valve. The oil inlets of the third one-way valve and the fourth one-way valve are both communicated with the oil tank of oil station two. The oil outlet of the third one-way valve is connected between the hydraulic control one-way valve A and the second switching valve A. The oil outlet of the fourth one-way valve is connected between the hydraulic control one-way valve B and the second switching valve B.

[0012] Pressure sensors for detecting the loading pressure are respectively connected to the hydraulic control locking valve group A and the hydraulic control locking valve group B.

[0013] The number of the pressure sensors is two. The two pressure sensors are respectively connected between the hydraulic control one-way valve A and the second switching valve A and between the hydraulic control one-way valve B and the second switching valve B through the third switching valve.

[0014] The test bench is horizontally arranged. A support frame for vertically fixing the digital hydraulic cylinder to be measured is provided on the upper surface of the test bench. The loading hydraulic cylinder is vertically fixed below the test bench.

[0015] An accumulator component is connected to oil station one. Water cooling components for cooling the oil are connected to both oil station one and oil station two.

[0016] Compared with the prior art, the beneficial effects of adopting the present invention are as follows: 1. The synchronous loading test system provided by the present invention can respectively provide different external loads for each digital hydraulic cylinder to be measured through the control unit, the power source unit, and the loading unit, and the provided external loads are all synchronously loaded. The displacement of each digital hydraulic cylinder to be measured under different loads can be measured through each displacement sensor, which can not only meet the synchronous test requirements of the digital hydraulic cylinder of the cylindrical valve, but also improve the control accuracy and operation reliability of the cylindrical valve. At the same time, it also provides a reference for the research and development of other similar hydraulic systems.

[0017] 2. A two-way hydraulically controlled locking valve group is arranged between the loading hydraulic cylinder and the electromagnetic reversing valve in the present invention. This two-way hydraulically controlled locking valve group functions as a hydraulic lock, which can reduce the oil leakage in the rodless chamber and the rod chamber of the loading hydraulic cylinder when the electromagnetic reversing valve is in the zero position. In addition, the force sensor can detect the load of the measured digital hydraulic cylinder in real time, which is convenient to correspond to the displacement output under each load, and accurately obtain the displacement output information of each measured digital hydraulic cylinder under different loads, making the synchronous test results of each measured digital hydraulic cylinder more accurate and intuitive.

[0018] 3. The present invention can automatically adjust the loading pressure of the loading hydraulic cylinder through the cooperation of the one-way self-compensating oil supply component and the load regulating component. Specifically, when the piston rod of the measured digital hydraulic cylinder moves upward or downward, the control unit changes the set pressure of the proportional valve, so that the oil in the rod chamber or the rodless chamber of the loading hydraulic cylinder is discharged according to the set pressure, and the loading pressure of the loading hydraulic cylinder can be adjusted in real time, thereby providing different loads for the measured digital hydraulic cylinder, and the operation conditions of the digital hydraulic cylinder under different loads can be simulated in this way. In addition, during this test process, the oil in the loading hydraulic cylinder is locked by the two-way hydraulically controlled locking valve group, and the oil cannot be discharged through the electromagnetic reversing valve. Therefore, when the piston rod of the measured digital hydraulic cylinder moves upward, it synchronously drives the piston rod of the loading hydraulic cylinder to move upward. At this time, the oil in the rod chamber is compressed and discharged to the oil tank of oil station two through the proportional valve, and the volume of the rodless chamber increases and generates a negative pressure. Under the action of this negative pressure, the oil in the oil tank automatically enters the rodless chamber through the one-way self-compensating oil supply component. On the contrary, when the piston rod of the measured digital hydraulic cylinder moves downward, it synchronously drives the piston rod of the loading hydraulic cylinder to move downward. At this time, the oil in the rodless chamber is compressed and discharged to the oil tank of oil station two through the proportional valve, and the volume of the rod chamber increases and generates a negative pressure. Under the action of this negative pressure, the oil in the oil tank automatically enters the rod chamber through the one-way self-compensating oil supply component, so as to realize the adjustment of different loading pressures and the automatic replenishment of oil.

[0019] 4. The loading hydraulic cylinder of the present invention shares a proportional valve during the reciprocating loading process. The loading pressures during the reciprocating loading of the loading hydraulic cylinder are both regulated by the same proportional valve, and there is no need for oil pump control. The oil pump only plays the role of injecting oil into the rod chamber and the rodless chamber before the test, and the oil pump does not work during the test process. It has the advantages of simple structure, low cost, convenient operation, environmental protection and energy saving, and strong practicability.

[0020] 5. The pressure sensor in the present invention is beneficial to detect whether the loading pressure of the loading hydraulic cylinder reaches the set value and can adjust it when the loading pressure does not reach the set value.

[0021] 6. The present invention realizes the fixed connection between the piston rod of the loading hydraulic cylinder and the piston rod of the measured digital hydraulic cylinder through a hinge, which has the advantages of simple connection structure, stable and reliable connection.

[0022] 7. The present invention facilitates the stable and reliable fixation of the digital hydraulic cylinder to be measured on the test bench through the support frame, which is conducive to the rapid installation and disassembly of the digital hydraulic cylinder to be measured.

[0023] 8. The accumulator assembly of the present invention can absorb pressure shocks, which is conducive to maintaining the pressure stability of the oil pressure system. The water-cooling assembly is conducive to rapidly dissipating heat from the high-pressure oil, thereby ensuring the normal operation of the test system. Description of the Drawings

[0024] Figure 1 is a schematic diagram of the overall structure of the present invention; Figure 2 is a schematic diagram of the connection structure of a single set of loading unit and a single set of unit to be measured.

[0025] The labels in the figure are: 1. Control unit, 2. Power source unit, 3. Loading unit, 4. Unit to be measured, 5. Test bench, 6. Displacement sensor; 2.1. Oil station 1, 2.2. Oil station 2, 2.3. Accumulator assembly, 2.4. Water-cooling assembly; 3.1. Loading hydraulic cylinder, 3.2. First switching valve, 3.3. Electro-hydraulic directional valve, 3.4. Hydraulic control check valve A, 3.5. Second switching valve A, 3.6. Hydraulic control check valve B, 3.7. Second switching valve B, 3.8. Proportional valve, 3.9. Third switching valve, 3.10. Force sensor, 3.11. Pressure sensor, 3.12. First check valve, 3.13. Second check valve, 3.14. Third check valve, 3.15. Fourth check valve; 4.1. Digital hydraulic cylinder to be measured. Detailed Embodiments

[0026] Such as Figure 1As shown in the figure, the present invention provides a synchronous loading test system for a cylindrical valve digital hydraulic cylinder, which includes a control unit 1, a power source unit 2, a loading unit 3, a unit under test 4, a test bench 5, and displacement sensors 6. The power source unit 2 includes an oil station 1 (2.1) and an oil station 2 (2.2), and both the oil station 1 (2.1) and the oil station 2 (2.2) include an oil tank and an oil pump. The unit under test 4 includes six sets of digital hydraulic cylinders under test (4.1), and the loading unit 3 includes six sets of loading hydraulic cylinders (3.1) and six sets of loading components. Each set of digital hydraulic cylinders under test (4.1) is respectively fixed above the test bench 5, and each set of loading hydraulic cylinders (3.1) is respectively fixed below the test bench 5. The piston rods of each set of digital hydraulic cylinders under test (4.1) are respectively fixedly connected to the piston rods of each set of loading hydraulic cylinders (3.1). The number of displacement sensors 6 is six sets, and the six sets of displacement sensors 6 are respectively arranged on each loading hydraulic cylinder 3.1 to detect the displacement output of the piston rods of each digital hydraulic cylinder under test 4.1. The oil station 1 (2.1) provides high-pressure oil for each digital hydraulic cylinder under test 4.1 respectively, and the oil station 2 (2.2) provides high-pressure oil for each loading hydraulic cylinder 3.1 respectively through the loading components. The control unit 1 includes conventional components such as a PLC processor and an industrial computer. The control unit 1 is respectively connected to the power source unit 2, the loading unit 3, the unit under test 4, and the displacement sensors 6. The control unit 1 has the function of controlling each digital hydraulic cylinder under test 4.1 through the oil station 1 (2.1), the function of providing different external loads for each digital hydraulic cylinder under test 4.1 respectively through the power source unit 2 and the loading unit 3, the function of obtaining the displacements of each digital hydraulic cylinder under test 4.1 under different loads according to the displacement outputs detected by each displacement sensor 6, and the function of judging the synchronism of each digital hydraulic cylinder under test 4.1 by comparing the displacement outputs detected by each displacement sensor 6.

[0027] In a preferred embodiment, as Figure 1 shown, each digital hydraulic cylinder under test 4.1 and each loading hydraulic cylinder 3.1 are fixedly arranged in a straight line on the test bench 5. Correspondingly, according to the displacement sensors 6, it can be clearly and intuitively observed whether the piston rods of the six sets of digital hydraulic cylinders under test 4.1 are synchronous, which is beneficial to quickly detecting the digital hydraulic cylinders under test 4.1 with inconsistent synchronism.

[0028] It should be noted that in this embodiment, it is preferred to use the displacement sensors 6 to detect the displacement output of the piston rods of each digital hydraulic cylinder under test. During actual testing, other sensors with the same function can also be used.

[0029] In a preferred embodiment, as Figure 1As shown, the loading component includes a first switching valve 3.2, an electromagnetic directional valve 3.3, a one-way self-compensating oil component, a load regulating component, a force sensor 3.10, a hydraulic control locking valve group A and a hydraulic control locking valve group B. The piston rod of the loading hydraulic cylinder 3.1 is fixedly connected to the piston rod of the measured digital hydraulic cylinder 4.1 through a hinge, facilitating the quick disassembly and assembly between the two piston rods. The force sensor 3.10 is fixed between the piston rods of the loading hydraulic cylinder 3.1 and each measured digital hydraulic cylinder 4.1 and is connected to the control unit 1. The force sensor 3.10 is used to detect the load of the measured digital hydraulic cylinder 4.1. The electromagnetic directional valve 3.3 includes an oil inlet P, an oil drain port T, a working oil port A and a working oil port B. The oil inlet P of the electromagnetic directional valve 3.3 is connected to the oil pump through the first switching valve 3.2. The working oil port A is connected to the rodless cavity of the loading hydraulic cylinder 3.1 through the hydraulic control locking valve group A. The working oil port B is connected to the rod cavity of the loading hydraulic cylinder 3.1 through the hydraulic control locking valve group B. The oil drain port T is connected to the fuel tank. The one-way self-compensating oil component and the load regulating component are connected in parallel between the hydraulic control locking valve group A and the hydraulic control locking valve group B. The one-way self-compensating oil component and the load regulating component cooperate to regulate the loading pressure of the loading hydraulic cylinder 3.1.

[0030] As Figure 1 shown, in this embodiment, the hydraulic control locking valve group A includes a hydraulic control check valve A 3.4 and a second switching valve A 3.5. The hydraulic control locking valve group B includes a hydraulic control check valve B 3.6 and a second switching valve B 3.7. The hydraulic control check valve A 3.4 and the second switching valve A 3.5 are sequentially connected between the working oil port A and the rodless cavity through a pipeline. The hydraulic control check valve B 3.6 and the second switching valve B 3.7 are sequentially connected between the working oil port B and the rod cavity through a pipeline. The control cavity of the hydraulic control check valve A 3.4 is communicated with the working oil port B. The control cavity of the hydraulic control check valve B 3.6 is communicated with the working oil port A.

[0031] Generally, the electromagnetic directional control valve 3.3 has a neutral position, a left position, and a right position. When the oil is pumped from the oil pump and the first switching valve 3.2 to the oil inlet P of the electromagnetic switching valve, if the electromagnetic directional control valve 3.3 is controlled to be in the right position, the oil inlet P is communicated with the working oil port A and not communicated with the working oil port B. At this time, the oil enters the rodless cavity through the working oil port A and the second switching valve A3.5, and the piston rod in the loading hydraulic cylinder 3.1 moves upward. If the electromagnetic directional control valve 3.3 is controlled to be in the left position, the oil inlet P is communicated with the working oil port B and not communicated with the working oil port A. At this time, the oil enters the rod cavity through the working oil port B and the second switching valve B3.7, and the piston rod in the loading hydraulic cylinder 3.1 moves downward. Since the control cavity of the hydraulic control check valve A3.4 is communicated with the working oil port B, and the control cavity of the hydraulic control check valve B3.6 is communicated with the working oil port A, when injecting oil into the rodless cavity through the working oil port A, the oil also enters the control cavity of the hydraulic control check valve B3.6, closing the hydraulic control check valve B3.6, and the oil in the rod cavity cannot flow back through the hydraulic control check valve B3.6. Correspondingly, when injecting oil into the rod cavity through the working oil port B, the oil also enters the control cavity of the hydraulic control check valve A3.4, closing the hydraulic control check valve A3.4, and the oil in the rodless cavity cannot flow back through the hydraulic control check valve A3.4. If the electromagnetic directional control valve 3.3 is controlled to be in the neutral position, the oil inlet P is not communicated with both the working oil port A and the working oil port B. At this time, both the hydraulic control check valve A3.4 and the hydraulic control check valve B3.6 are locked, and the oil in the loading hydraulic cylinder 3.1 cannot be discharged through the electromagnetic directional control valve 3.3. In actual testing of this embodiment, it is necessary to first fill both the rod cavity and the rodless cavity of the loading hydraulic cylinder 3.1 with oil, and then control the electromagnetic directional control valve 3.3 to be in the neutral position to lock the hydraulic control check valve A3.4 and the hydraulic control check valve B3.6.

[0032] As Figure 1 shown, in this embodiment, the load adjustment assembly includes a proportional valve 3.8, a first check valve 3.12, and a second check valve 3.13. The oil inlet of the first check valve 3.12 is connected between the hydraulic control check valve A3.4 and the second switching valve A3.5. The oil inlet of the second check valve 3.13 is connected between the hydraulic control check valve B3.6 and the second switching valve B3.7. The oil outlets of the first check valve 3.12 and the second check valve 3.13 are both connected to the oil tank of the second oil station 2.2 through the proportional valve 3.8. The proportional valve 3.8 is connected to the control unit 1, and the control unit 1 can change the set pressure of the proportional valve 3.8. By changing the set pressure of the proportional valve 3.8, the loading pressure of the loading hydraulic cylinder 3.1 can be adjusted.

[0033] Specifically, when controlling the piston rod of the digital hydraulic cylinder 4.1 under test to move upward or downward, by changing the set pressure of the proportional valve 3.8 through the control unit 1, the flow rate and velocity of the hydraulic oil flowing out of the rod chamber or the non-rod chamber in the loading hydraulic cylinder 3.1 through the proportional valve 3.8 can be adjusted, and thus the loading pressure of the loading hydraulic cylinder 3.1 can be adjusted, so as to provide different external loads for the digital hydraulic cylinder 4.1 under test.

[0034] As Figure 1 shown, in this embodiment, the one-way self-compensating oil component includes a third one-way valve 3.14 and a fourth one-way valve 3.15. The oil inlets of the third one-way valve 3.14 and the fourth one-way valve 3.15 are both connected to the fuel tank of the oil station two 2.2. The oil outlet of the third one-way valve 3.14 is connected between the hydraulic control one-way valve A 3.4 and the second switching valve A 3.5, and the oil outlet of the fourth one-way valve 3.15 is connected between the hydraulic control one-way valve B 3.6 and the second switching valve B 3.7. During the test, since the hydraulic control one-way valve A 3.4 and the hydraulic control one-way valve B 3.6 are both locked when the electromagnetic reversing valve 3.3 is in the zero position, when the area of the non-rod chamber or the rod chamber in the loading hydraulic cylinder 3.1 increases and generates negative pressure, the hydraulic oil in the fuel tank can be automatically replenished into the non-rod chamber or the rod chamber through the third one-way valve 3.14 or the fourth one-way valve 3.15.

[0035] As Figure 1 shown, in this embodiment, pressure sensors 3.11 for detecting whether the loading pressure of the loading hydraulic cylinder 3.1 reaches the set value are respectively connected to the hydraulic control locking valve group A and the hydraulic control locking valve group B. The number of the pressure sensors 3.11 is two. The two pressure sensors 3.11 are respectively connected between the hydraulic control one-way valve A 3.4 and the second switching valve A 3.5 and between the hydraulic control one-way valve B 3.6 and the second switching valve B 3.7 through the third switching valve 3.9, and are used to respectively detect whether the loading pressures of the non-rod chamber and the rod chamber reach the set value.

[0036] In a preferred embodiment, as Figure 1 shown, the test bench 5 is horizontally arranged. A support frame (not shown in the figure) for vertically fixing the digital hydraulic cylinder 4.1 under test is provided on the upper surface of the test bench 5, and the loading hydraulic cylinder 3.1 is vertically fixed below the test bench 5.

[0037] In a preferred embodiment, as Figure 1 shown, an accumulator assembly 2.3 is connected to the oil station one 2.1, and a water cooling assembly 2.4 for cooling the hydraulic oil is connected to both the oil station one 2.1 and the oil station two 2.2.

[0038] Among them, in the hydraulic servo system, the servo valve has a relatively high transient response frequency, so the required transient flow rate is large, which causes large fluctuations in the oil. In addition, during the high-frequency square wave loading process of the hydraulic servo system, pressure shocks may be triggered. For this reason, in this embodiment, an accumulator assembly 2.3 is connected to the oil station 2.1, which can not only quickly supplement the flow rate required by the hydraulic servo system, but also effectively maintain the pressure stability of the hydraulic servo system and well absorb the pressure shock, thus ensuring the stable operation of the test system.

[0039] Furthermore, during actual testing, the power source unit 2 needs to provide high-pressure oil to the loading unit 3 and the unit under test 4. At this time, the high-pressure oil generates a large amount of heat. Considering aspects such as cooling effect, power consumption, and occupied area, in this embodiment, water-cooling components 2.4 are respectively connected to the oil station 2.1 and the oil station 2.2, which is beneficial to quickly cool the high-pressure oil, thus ensuring the stable operation of the test system.

[0040] It should be noted that the above accumulator assembly 2.3 and water-cooling components 2.4 are both existing conventional technologies and will not be elaborated here.

[0041] As Figure 1 、 2 shown, the test principle of the present invention is as follows: 1. Control all electromagnetic directional valves 3.3 to be in the right position, so that the oil inlet P is connected to the working oil port A, start the oil pump of the oil station 2.2, and use the hydraulic control check valve A 3.4 and the second switching valve A 3.5 to inject oil into the rodless cavity of each loading hydraulic cylinder 3.1 until the piston moves upward to the uppermost position of each loading hydraulic cylinder 3.1. Then control the electromagnetic directional valve 3.3 to be in the left position, so that the oil inlet P is connected to the working oil port B, and use the hydraulic control check valve B 3.6 and the second switching valve B 3.7 to inject oil into the rod cavity of each loading hydraulic cylinder 3.1. Under the action of the oil pressure, the piston moves downward. When the piston moves to a suitable position (for example, the middle of each loading hydraulic cylinder 3.1), control the electromagnetic directional valve 3.3 to be in the zero position, lock the hydraulic control check valve A 3.4 and the hydraulic control check valve, and at the same time stop the oil pump.

[0042] 2. Control the piston rod of the measured digital hydraulic cylinder 4.1 to move upward or downward for testing. By adjusting the set pressures of the proportional valves 3.8 differently through the control unit 1, the oil in the rod chamber or rodless chamber of the loading hydraulic cylinder 3.1 is discharged according to the set pressure, so as to provide different external loads for each measured digital hydraulic cylinder 4.1. During this process, the oil in each loading hydraulic cylinder 3.1 is locked by the two-way pilot-operated locking valve group, and the oil cannot be discharged through the electromagnetic directional valve 3.3. When the piston rod of each measured digital hydraulic cylinder 4.1 moves upward, it synchronously drives the piston rod of each loading hydraulic cylinder 3.1 to move upward. At this time, the oil in the rod chamber is compressed and discharged to the fuel tank through the proportional valve 3.8, and the volume of the rodless chamber increases and generates a negative pressure. Under the action of this negative pressure, the oil in the fuel tank automatically enters the rodless chamber through the third one-way valve 3.14. Conversely, when the piston rod of each measured digital hydraulic cylinder 4.1 moves downward, it synchronously drives the piston rod of each loading hydraulic cylinder 3.1 to move downward. At this time, the oil in the rodless chamber is compressed and discharged to the fuel tank through the proportional valve 3.8, and the volume of the rod chamber increases and generates a negative pressure. Under the action of this negative pressure, the oil in the fuel tank automatically enters the rod chamber through the fourth one-way valve 3.15, so as to realize the adjustment of different loading pressures and the automatic replenishment of oil.

[0043] 3. During the above process, the displacement sensors 6 are used to detect the displacement outputs of the piston rods of the measured digital hydraulic cylinders 4.1 respectively, and send the detected displacement outputs to the control unit 1. The control unit 1 judges whether the measured digital hydraulic cylinders 4.1 are synchronous under different loads according to the received displacement outputs.

[0044] Generally speaking, the synchronous loading test system provided by the present invention can effectively test the synchronism of each measured digital hydraulic cylinder 4.1 under different loads, meets the synchronous test requirements of the digital hydraulic cylinder of the cylindrical valve, improves the control accuracy and operation reliability of the cylindrical valve, and also provides a reference for the research and development of other similar hydraulic systems.

[0045] The above is only the specific implementation manner of the present invention. Any feature disclosed in this specification, unless specifically described, can be replaced by other equivalent or similar-purpose alternative features; all the features disclosed, or all the steps in any method or process, except for mutually exclusive features and / or steps, can be combined in any way.

Claims

1. A digital hydraulic cylinder synchronous loading test system for a cylindrical valve, characterized in that: It includes a control unit (1), a power source unit (2), a loading unit (3), a unit under test (4), a test bench (5) and a displacement sensor (6). The power source unit (2) includes an oil station one (2.1) and an oil station two (2.2). The unit under test (4) includes six digital hydraulic cylinders under test (4.1). The loading unit (3) includes six loading hydraulic cylinders (3.1) and six loading assemblies. The digital hydraulic cylinders under test (4.1) are respectively fixed above the test bench (5), and the loading hydraulic cylinders (3.1) are respectively fixed below the test bench (5). The piston rods of the respective digital hydraulic cylinders under test (4.1) are fixedly connected to the piston rods of the respective loading hydraulic cylinders (3.1). The displacement sensors (6) are respectively arranged on the respective loading hydraulic cylinders (3.1) and are used to detect the displacement output of the piston rods of the digital hydraulic cylinders under test (4.1). The oil station one (2.1) respectively provides high-pressure oil for the respective digital hydraulic cylinders under test (4.1), and the oil station two (2.2) respectively provides high-pressure oil for the respective loading hydraulic cylinders (3.1) through the loading assemblies. The control unit (1) is respectively connected to the power source unit (2), the loading unit (3), the unit under test (4) and the displacement sensor (6), and is used to respectively provide different external loads for the respective digital hydraulic cylinders under test (4.1) through the power source unit (2) and the loading unit (3), and obtain the displacements of the respective digital hydraulic cylinders under test (4.1) under different loads according to the displacement outputs detected by the respective displacement sensors (6), and is used to judge the synchronism of the respective digital hydraulic cylinders under test (..1).

2. The digital hydraulic cylinder synchronous loading test system for a cylindrical valve according to claim 1, wherein: The digital hydraulic cylinders under test (4.1) and the loading hydraulic cylinders (3.1) are both fixedly arranged in a linear layout on the test bench (5).

3. A digital hydraulic cylinder synchronous loading test system for a cylindrical valve according to claim 1 or 2, characterized in that: The loading assembly includes a first switching valve (3.2), an electromagnetic directional valve (3.3), a one-way self-compensating oil supply assembly, a load regulating assembly, a force sensor (3.10), a hydraulic control locking valve group A and a hydraulic control locking valve group B. The piston rod of the loading hydraulic cylinder (3.1) is fixedly connected to the piston rod of the digital hydraulic cylinder under test (4.1) through a hinge. The force sensor (3.10) is fixed between the piston rod of the loading hydraulic cylinder (3.1) and the piston rod of the respective digital hydraulic cylinders under test (4.1) and is connected to the control unit (1) and is used to detect the load of the digital hydraulic cylinder under test (4.1). The oil inlet P of the electromagnetic directional valve (3.3) is connected to an oil pump through the first switching valve (3.2). The working oil ports A and B of the electromagnetic directional valve (3.3) are respectively connected to the rodless cavity and the rod cavity of the loading hydraulic cylinder (3.1) through the hydraulic control locking valve group A and the hydraulic control locking valve group B. The one-way self-compensating oil supply assembly and the load regulating assembly are connected in parallel between the hydraulic control locking valve group A and the hydraulic control locking valve group B, and the one-way self-compensating oil supply assembly and the load regulating assembly cooperate to regulate the loading pressure of the loading hydraulic cylinder (3.1).

4. A digital hydraulic cylinder synchronous loading test system for a cylindrical valve according to claim 3, characterized in that: The hydraulic control locking valve group A includes a hydraulic control check valve A (3.4) and a second switching valve A (3.5), and the hydraulic control locking valve group B includes a hydraulic control check valve B (3.6) and a second switching valve B (3.7). The hydraulic control check valve A (3.4) and the second switching valve A (3.5) are sequentially connected between the working oil port A and the rodless cavity. The hydraulic control check valve B (3.6) and the second switching valve B (3.7) are sequentially connected between the working oil port B and the rod end cavity. The control cavity of the hydraulic control check valve A (3.4) is communicated with the working oil port B, and the control cavity of the hydraulic control check valve B (3.6) is communicated with the working oil port A.

5. A digital hydraulic cylinder synchronous loading test system for a cylindrical valve according to claim 3, characterized in that: The load regulating assembly includes a proportional valve (3.8), a first check valve (3.12) and a second check valve (3.13). The inlet of the first check valve (3.12) is connected between the hydraulic control check valve A (3.4) and the second switching valve A (3.5). The inlet of the second check valve (3.13) is connected between the hydraulic control check valve B (3.6) and the second switching valve B (3.7). The outlets of the first check valve (3.12) and the second check valve (3.13) are both connected to the oil tank of the second oil station (2.2) through the proportional valve (3.8). The proportional valve (3.8) is connected to the control unit (1), and the control unit (1) adjusts the loading pressure by adjusting the set pressure of the proportional valve (3.8).

6. A digital hydraulic cylinder synchronous loading test system for a cylindrical valve according to claim 3, characterized in that: The one-way self-compensating oil supply assembly includes a third check valve (3.14) and a fourth check valve (3.15). The inlets of the third check valve (3.14) and the fourth check valve (3.15) are both communicated with the oil tank of the second oil station (2.2). The outlet of the third check valve (3.14) is connected between the hydraulic control check valve A (3.4) and the second switching valve A (3.5). The outlet of the fourth check valve (3.15) is connected between the hydraulic control check valve B (3.6) and the second switching valve B (3.7).

7. A digital hydraulic cylinder synchronous loading test system for a cylindrical valve according to claim 3, characterized in that: Pressure sensors (3.11) for detecting the loading pressure are respectively connected to the hydraulic control locking valve group A and the hydraulic control locking valve group B.

8. A digital hydraulic cylinder synchronous loading test system for a cylindrical valve according to claim 7, characterized in that: The number of the pressure sensors (3.11) is two. The two pressure sensors (3.11) are respectively connected between the hydraulic control check valve A (3.4) and the second switching valve A (3.5) and between the hydraulic control check valve B (3.6) and the second switching valve B (3.7) through the third switching valve (3.9).

9. A digital hydraulic cylinder synchronous loading test system for a cylindrical valve according to claim 1, characterized in that: The test bench (5) is horizontally arranged. The upper surface of the test bench (5) is provided with a support frame for vertically fixing the measured digital hydraulic cylinder (4.1). The loading hydraulic cylinder (3.1) is vertically fixed below the test bench (5).

10. A digital hydraulic cylinder synchronous loading test system for a cylindrical valve according to claim 1, characterized in that: An accumulator assembly (2.3) is connected to the first oil station (2.1). Water cooling assemblies (2.4) for cooling the oil are respectively connected to the first oil station (2.1) and the second oil station (2.2).

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