Hydraulic control system and method of high-speed hydraulic driving impact device

Abstract

The invention discloses a hydraulic control system and method for a high-speed hydraulic drive impact device. The system adopts a bistable positive feedback valveless flow control structure, and a trigger sleeve is linked with a piston rod to dynamically adjust the opening degree of a main oil inlet, so that an avalanche acceleration mechanism is formed, and valve control delay is eliminated; the inflation pressure adjusting module is linked with the piston energy accumulator through an inflation adjusting energy accumulator with a preset volume ratio, and the inflation pressure is reversely adjusted through oil pressure; the oil supplementing energy accumulator is used for supplementing oil in an anti-vacuum manner through a radial thin oil duct; the hydraulic control two-position seven-way valve switches an oil recovery mode and a reset mode. Valve control delay is broken through, the energy transmission efficiency and the system reliability are improved, and the heavy-load high-speed movement requirement of high-energy explosion impact simulation is met.

Description

Technical Field

[0001] This invention relates to the technical field of explosion impact simulation testing, and in particular to the technical field of a hydraulic control system and method for a high-speed hydraulically driven impact device. Background Technology

[0002] Explosion impact simulation testing is a test used to simulate the impact waves, pressure waves, and vibrations generated during an explosion on the response and performance of objects, structures, or materials, in order to study the durability and safety of the target object, structure, or material. Current technologies mainly utilize pendulum-type, falling-weight type, or Hopkinson bar type impact test benches. These devices have the following drawbacks: 1. Energy limitation: It can only achieve low-energy impacts and cannot meet the requirements for simulating high-energy explosive impacts; 2. Poor compatibility with operating conditions: It cannot simultaneously support experimental conditions involving high-speed motion and heavy loads; 3. Low level of digitization: lack of high-precision, digital, and modular testing methods.

[0003] Ultimately, the bottleneck of the hydraulic control system lies in: Traditional valve-controlled flow structures have slow response speeds, making it difficult to meet instantaneous high flow rate demands; the energy transfer path of accumulators is complex, resulting in local pressure losses due to fluid resistance; and the functions of oil recovery and energy management are dispersed, leading to low system reliability.

[0004] Therefore, there is an urgent need to develop a high-speed hydraulic drive impact control system that integrates efficient flow control, precise energy management, and low-loss hydraulic transmission. Summary of the Invention

[0005] The purpose of this invention is to solve the problems in the prior art and to propose a hydraulic control system and method for a high-speed hydraulically driven impact device, which can enable the impact trigger response speed to break through the valve control delay limit, improve the hydraulic energy transmission efficiency, and make the oil replenishment and recovery process precise and controllable.

[0006] To achieve the above objectives, this invention proposes a hydraulic control method for a high-speed hydraulically driven impact device, comprising the following steps: (a) The hydraulic shock generator triggers the shock through a bistable positive feedback valveless flow control structure: When the impact start valve is energized, the high-pressure oil from the impact start accumulator enters the trigger chamber and pushes the trigger sleeve; the displacement of the trigger sleeve causes the piston rod to pass over the main oil inlet, allowing the high-pressure oil from the piston accumulator to enter the plug chamber; the opening of the main oil inlet dynamically increases with the increase of the piston rod displacement, promoting the accelerated movement of the piston rod; (b) The pressurization and control hydraulic system performs fluid management through a multi-functional valve block: Oil supply: The high-pressure pump unit supplies oil to the piston accumulator; Oil replenishment: The oil replenishment accumulator replenishes oil to the anti-vacuum chamber through the radial fine oil channel of the trigger column; Oil recovery: When the hydraulic control two-position seven-way valve is in the left position, the oil in the return oil tank / buffer tank is recovered to the drain oil tank. (c) Precise adjustment of inflation pressure: The air-regulating accumulator regulates the oil pressure through a proportional overflow valve, driving its air chamber to connect with the piston accumulator's air chamber, synchronously adjusting the air pressure, and simultaneously absorbing pump source pulsation to stabilize the pressure. (d) Transferring energy through an energy storage device: The piston accumulator releases energy and converts it into the kinetic energy of the piston rod and the impact load, which then impacts the test piece at a specified speed.

[0007] This invention also proposes a hydraulic control system for a high-speed hydraulically driven impact device, comprising: Hydraulic shock generating device: shock actuator, with a trigger column and trigger sleeve inside the base; hydraulic two-position seven-way valve, shock start valve, pressure sensor, high-frequency pressure sensor and bistable positive feedback valveless flow control structure; wherein the bistable positive feedback valveless flow control structure includes a trigger sleeve inside the base, one end of the trigger sleeve has multiple evenly distributed grooves, which cooperate with multiple rounded arc grooves at the piston rod end to form an oil pressure feedback channel; Hydraulic boosting and control system: including high pressure pump set, circulating pump set, oil drain recovery module, oil replenishment accumulator, multi-functional valve block, piston accumulator, the multi-functional valve block integrates accumulator charging pressure adjustment module, accumulator charging module, and impact reset module; Positive feedback high-speed hydraulic drive system: Through the interaction between the hydraulic shock generator and the oil circuit of the boosting and control hydraulic system, the above-mentioned closed loop of oil supply, replenishment and recovery is realized.

[0008] The oil tank of the pressurization and control hydraulic system is divided into a main oil tank and a drain oil tank. The drain oil tank is located below the main oil tank, and the buffer oil flows back to the drain oil tank by its own weight.

[0009] Preferably, in the pressurization and control hydraulic system: the high-pressure pump group adjusts the oil supply pressure through a proportional relief valve; the hydraulically controlled two-position seven-way valve performs oil recovery when in the left position and piston rod reset when in the right position; the oil replenishment accumulator replenishes the plug cavity for vacuum prevention through radial fine oil channels in the trigger column.

[0010] The hydraulic shock generator is in a static, closed steady state before startup and in an impact-triggered steady state after startup. It forms a bistable positive feedback "avalanche" valveless flow control structure with the main oil inlet, trigger sleeve, and piston rod, replacing the traditional valve control to meet instantaneous high flow requirements.

[0011] Preferably, the accumulator charging pressure adjustment module includes a proportional overflow valve, a charging regulating accumulator, and a nitrogen pre-charging port. The gas chamber of the charging regulating accumulator is connected to the gas chamber of the piston accumulator, and the charging pressure is adjusted in reverse by oil pressure. The accumulator oil filling module includes a gear flow meter and an overflow valve.

[0012] Preferably, in the accumulator charging pressure adjustment module, the ratio of the charging adjustment accumulator volume to the total volume of the piston accumulator is determined by engineering calculation to ensure that the compressed volume of the air chamber does not exceed 3 / 4 of the total volume. The oil pressure is adjusted by the proportional overflow valve to drive the air chamber pressure balance and realize stepless adjustment of the charging pressure.

[0013] Preferably, the oil replenishing accumulator is connected to one axial coarse oil passage and multiple radial fine oil passages inside the trigger column; the piston accumulator is directly connected to the plug cavity via multiple 25° inclined main oil inlets on the base.

[0014] Preferably, the hydraulically controlled two-position seven-way valve is configured as follows: left position: connecting the exhaust port and return port of the return oil tank / buffer tank to the drain oil tank; right position: cutting off the exhaust / return oil passage, allowing the reset oil to enter the rod chamber through the damping hole to push the piston rod to reset.

[0015] Preferably, the pressurization and control hydraulic system further includes a hydraulic power unit, which includes: a high-pressure pump set, which regulates the oil supply pressure through a proportional relief valve and limits the maximum system pressure through a relief valve; a circulation pump set, which purifies the oil through a filter; and an oil drain recovery module, which recovers the oil from the drain tank to the main tank through an oil drain pump set.

[0016] The beneficial effects of this invention are: 1. Breakthrough solution to the valve control delay problem By using a bistable positive feedback valveless flow control structure (with the trigger sleeve linked to the dynamic opening of the main inlet), the response delay of traditional solenoid valves is eliminated, achieving millisecond-level impact triggering and meeting the instantaneous high flow rate requirements of explosion impact simulation.

[0017] 2. Significantly improved hydraulic energy management efficiency Multifunctional valve block integrated design: The air pressure adjustment module accurately matches the accumulator air pressure through a proportional overflow valve to avoid energy waste; the oil filling module quantitatively controls the oil volume through a gear flow meter, resulting in small oil filling errors; Accumulator direct drive technology: 25° main oil inlet reduces local fluid resistance loss.

[0018] 3. System reliability has been comprehensively improved. The hydraulically controlled two-position seven-way valve features dual-mode switching (left position for oil return / right position for reset), avoiding interference between oil recovery and reset processes; the oil replenishment accumulator provides real-time anti-vacuum oil replenishment through multiple radial fine oil channels, significantly reducing the risk of cavitation.

[0019] The features and advantages of the present invention will be described in detail through embodiments and in conjunction with the accompanying drawings. Attached Figure Description

[0020] Figure 1 This is a system principle block diagram of the hydraulic control system and method of a high-speed hydraulically driven impact device according to the present invention; Figure 2 This is a hydraulic system schematic diagram of the hydraulic control system and method of a high-speed hydraulically driven impact device according to the present invention; Figure 3 This invention relates to a bistable valveless flow control structure principle of a hydraulic control system and method for a high-speed hydraulically driven impact device. Figure 1 ; Figure 4 This invention relates to a bistable valveless flow control structure principle of a hydraulic control system and method for a high-speed hydraulically driven impact device. Figure 2 ; Figure 5 This is a perspective view of the impact start valve of the hydraulic control system and method of a high-speed hydraulically driven impact device according to the present invention. Figure 6 This is a perspective view of a hydraulically controlled two-position seven-way valve of the hydraulic control system and method of a high-speed hydraulically driven impact device according to the present invention. Figure 7 This is a front perspective view of the pressurization and control hydraulic system of the hydraulic control system and method of the high-speed hydraulically driven impact device of the present invention. Figure 8 This is a rear perspective view of the pressurization and control hydraulic system of the hydraulic control system and method of the high-speed hydraulically driven impact device of the present invention.

[0021] In the diagram: 1. Main oil tank; 2. Level sensor; 3. Temperature sensor; 4. Air filter; 5. Proportional relief valve; 6. Pressure sensor; 7. High-pressure pump set; 8. Relief valve; 9. Filter; 10. Circulation pump set; 11. Pressure gauge; 12. Discharge pump set; 13. Drain oil tank; 14. Two-position four-way solenoid directional valve; 15. Check valve; 16. Gas charging regulating accumulator; 17. High-pressure gas shut-off valve; 18. Nitrogen pre-charge port; 19. Shut-off valve; 20. Gear flow meter; 21. High-frequency pressure sensor; 22. Drain valve; 23. Impact start accumulator; 24. Oil replenishment accumulator; 25. Hydraulic two-position six-way valve; 26. Multifunctional valve block; 27. Impact start valve, 28. Piston accumulator, 29. Hydraulic 2-position 7-way valve, 30. Base plate, 31. Base, 32. Flange, 33. Cylinder body, 34. Impact start valve fixing plate, 35. Hydraulic 2-position 7-way valve fixing plate, 36. Front end cover, 37. Safety cover, 38. Piston rod, 39. Impact isolation block, 40. Safety block, 41. Return oil end cover, 42. Valve block, 43. Base plate, 44. High pressure oil end cover, 45. Upper end cover, 46. Valve body, 47. Lower end cover, 48. Fixing hole, 49. Cleaning hole cover, 50. Main oil tank drain port, 51. Visual level gauge, 52. Hook, 53. Oil inlet, 54. Spring, 55. Valve core, 56. Lower push rod. Detailed Implementation

[0022] See Figures 1-8 The method of the present invention includes the following steps: (a) The hydraulic shock generator triggers the shock through a bistable positive feedback valveless flow control structure: When the impact start valve 27 is energized, the high-pressure oil in the impact start accumulator 23 enters the trigger chamber and pushes the trigger sleeve; the displacement of the trigger sleeve causes the piston rod 38 to pass over the main oil inlet, so that the high-pressure oil in the piston accumulator 28 enters the plug chamber; the opening of the main oil inlet increases dynamically as the displacement of the piston rod 38 increases, promoting the accelerated movement of the piston rod. (b) The pressurization and control hydraulic system performs fluid management via the multi-function valve block 26: Oil supply: High-pressure pump set 7 supplies oil to piston accumulator 28; Oil replenishment: Oil replenishment accumulator 24 replenishes oil to the anti-vacuum plug cavity through the radial fine oil channel of the trigger column; Oil recovery: When the hydraulic control two-position seven-way valve 29 is in the left position, it recovers the oil from the return oil tank / buffer tank to the drain oil tank 13; (c) Precise adjustment of inflation pressure: The gas-regulating accumulator 16 regulates the oil pressure via the proportional relief valve 5, driving its gas chamber to connect with the gas chamber of the piston accumulator 28, synchronously adjusting the charging pressure, and simultaneously absorbing pump source pulsations for pressure stabilization. (It should be noted that the volume ratio of the gas-regulating accumulator 16 to the piston accumulator 28 is not limited to 2:1; its value needs to be determined through fluid dynamics calculations. The core principle is: when the proportional relief valve 5 regulates the oil pressure, the compressed volume of the accumulator's gas chamber must not exceed 3 / 4 of its total volume (the safety limit for bladder-type accumulators). The actual ratio depends on the system pressure, impact energy, and other operating conditions.) (d) Transferring energy through an energy storage device: The piston accumulator 28 releases energy and converts it into the kinetic energy of the piston rod 38 and the impact load, which then impacts the test piece at a specified speed.

[0023] The system of the present invention includes: Hydraulic shock generating device: shock actuator, with a trigger column and trigger sleeve inside the base 31; hydraulic control two-position seven-way valve 29, shock start valve 27, pressure sensor 6, high frequency pressure sensor 21 and bistable positive feedback valveless flow control structure; wherein the bistable positive feedback valveless flow control structure includes a trigger sleeve inside the base 31, one end of the trigger sleeve is provided with multiple evenly distributed grooves, which cooperate with multiple rounded arc grooves at the end of the piston rod 38 to form an oil pressure feedback channel; The pressurization and control hydraulic system includes a high-pressure pump group 7, a circulating pump group 10, an oil drain recovery module, an oil replenishment accumulator 24, a multi-functional valve block 26, and a piston accumulator 28. The multi-functional valve block 26 integrates an accumulator charging pressure adjustment module, an accumulator oil filling module, and an impact reset module. Positive feedback high-speed hydraulic drive system: Through the interaction between the hydraulic shock generator and the oil circuit of the boosting and control hydraulic system, the above-mentioned closed loop of oil supply, replenishment and recovery is realized.

[0024] Working process of this invention: The hydraulic control system and method of the high-speed hydraulically driven impact device of the present invention are described in conjunction with the accompanying drawings during operation.

[0025] Reference Figure 1 The test includes a hydraulic impact generating device and a pressurization and control hydraulic system. The working steps of the hydraulic impact generating device are divided into start-up, acceleration, buffering and reset processes. The pressurization and control system provides oil to the piston accumulator and recovers oil from the return oil tank and the buffer tank. After the hydraulic energy stored in the piston accumulator is released, it is converted into the kinetic energy of the piston rod of the actuator and the impact load. The impact load then impacts the test piece at a specified speed.

[0026] Reference Figure 2The piston accumulator 28 is equipped with a pressure sensor 6 and a temperature sensor 3 at its charging end. The plug cavity and rod cavity of the impact actuator are equipped with a high-frequency pressure sensor 21. The exhaust port and oil drain port of the return oil tank and the buffer tank are connected to the hydraulic control two-position seven-way valve 29. The rectangular through-hole of the cylinder is connected to the return oil tank. The three circular through-damping holes are connected to the buffer tank. The exhaust port of the front cover gap is connected to the return oil tank.

[0027] Reference Figure 2 The multi-functional valve block 26 integrates accumulator charging pressure adjustment, oil filling, and impact reset modules, and performs oil recovery through a hydraulically controlled two-position seven-way valve 29, forming a supply-replenishment-recovery closed loop. During impact reset, the oil is recovered to the drain tank 13 via the right position of the hydraulically controlled two-position seven-way valve 29. The proportional relief valve 5 is used to regulate the system pressure and controls the pressure of the charging regulating accumulator 16 in the accumulator charging pressure adjustment module. The charging pressure adjustment module controls the oil pressure of the charging regulating accumulator 16 through the proportional relief valve 5, so that its gas chamber pressure is transmitted to the piston accumulator 28. Since the volume of the charging regulating accumulator (80L) is twice the total volume of the piston accumulator (40L), it can quickly balance the gas pressure and suppress oil pressure fluctuations.

[0028] The number of accumulators (such as oil replenishment accumulator 24, impact start accumulator 23, etc.) can be increased or decreased according to the load energy demand; the volume of the gas regulating accumulator 16 is also not a fixed value, and its volume ratio with the piston accumulator 28 must meet the gas chamber compression constraint condition.

[0029] Reference Figure 3 , 4 After the impact start valve is energized and opened, the impact start oil passage in the base connects to the high-pressure oil in the piston accumulator, pushing the trigger sleeve and piston rod to the right. The replenishing oil accumulator replenishes the rapidly increasing volume of the plug cavity through the replenishing oil passage in the base plate to prevent vacuum. When the piston rod plug end passes the main oil inlet, the high-pressure oil in the piston accumulator enters the plug cavity, generating sufficient pressure to push the piston to continue moving to the right. At this time, the trigger sleeve has reached its limit position and disengages from the piston rod. The piston rod begins to accelerate to the right under the push of the high-pressure oil in the piston accumulator. As the piston rod moves further to the right, the opening of the main oil inlet increases, forming positive feedback that further promotes the acceleration of the piston rod to the right. Therefore, the working state of the hydraulic impact generator is divided into a static closed steady state before start-up and an impact trigger steady state after start-up. The bistable positive feedback "avalanche" valveless flow control structure formed by the main oil inlet, trigger sleeve, and piston rod replaces the traditional valve control to meet the instantaneous high flow requirements of the impact process. When the piston rod 38 passes the main oil inlet, the system switches from a static closed steady state to an impact-triggered steady state, forming positive feedback acceleration.

[0030] Reference Figure 2 , Figure 5The impact start valve 27 includes an impact start accumulator 23, a replenishing oil accumulator 24, a return oil end cap 41, a pressure sensor 6, a one-way valve 15, a valve block 42, a base plate 43, a high-pressure oil end cap 44, and a two-position four-way solenoid directional valve 14. During the pre-pressurization process, the high-pressure pump group 7 provides high-pressure oil to the impact start accumulator 23 and the replenishing oil accumulator 24. During the impact start process, the two-position four-way solenoid directional valve 14 is energized and placed in the left position. The impact start accumulator 23 provides high-pressure oil to the plug cavity to trigger the trigger sleeve and piston rod in the impact actuator cylinder. The replenishing oil accumulator 24 replenishes the plug cavity with oil during the impact triggering process to prevent the generation of a vacuum.

[0031] Reference Figure 6 The hydraulically controlled two-position seven-way valve 29 includes an upper end cover 45, a valve body 46, and a lower end cover 47. The internal components of the valve body 46 include a spring 54, a lower push rod 56, and a valve core 55. The spring 54 is sleeved outside the lower push rod and inside the valve core 55. The lower push rod is fixed to the lower end cover 47 by threads.

[0032] Reference Figure 7 , Figure 8 The pressurization and control hydraulic system specifically includes an air-regulating accumulator 16, a fixing hole 48, a cleaning hole cover 49, a main oil tank drain port 50, a visual level gauge 51, a temperature sensor 3, a circulating pump group 10, a multi-functional valve block 26, a nitrogen pre-charge port 18, a hook 52, a main oil tank 1, a pressure gauge 11, an oil filling port 53, a high-pressure pump group 7, a drain oil tank 13, a level sensor 2, a drain pump group 12, and a filter 9.

[0033] The gas-regulating accumulator 16 is located on the left side of the main oil tank 1. The nitrogen pre-charge port 18 is connected to the piston accumulator 28 through the high-pressure gas shut-off valve. The fixing hole 48 is used to fix the pressurization and control hydraulic system. Two cleaning hole covers 49 are located on the front of the main oil tank 1. After removing the fixing bolts, they can be used for manual cleaning of the interior. The main oil tank drain port 50 is located below the main oil tank 1 for draining oil from the main oil tank. The visual level gauge 51 is located between the two cleaning hole covers 49 for observing the liquid level of the main oil tank 1. The temperature sensor 3, the circulating pump group 10, the liquid level sensor 2 of the main oil tank, and the multi-functional valve block 26 are located above the main oil tank 1. The circulating pump group 10 and the filter 9 are used to filter oil impurities.

[0034] The high-pressure pump set 7, the drain oil tank 13, and the discharge pump set 12 are located below the main oil tank 1. The drain oil tank 13 is equipped with a liquid level sensor 2. The vent and return oil ports of the drain oil tank 13 are connected to the vent and discharge ports of the lower end cover of the hydraulic two-position seven-way valve 29, respectively. The oil inlet 53 is located on the back of the main oil tank 1 and is used to add oil to the main oil tank 1. The pressure gauges 11 in the pressure boosting and control hydraulic system are located above the main oil tank 1.

[0035] The above embodiments are illustrative of the present invention and are not intended to limit the present invention. Any simple modifications to the present invention are within the scope of protection of the present invention.

Claims

1. A hydraulic control method for a high-speed hydraulically driven impact device, characterized in that: Includes the following steps: (a) The hydraulic shock generator triggers the shock through a bistable positive feedback valveless flow control structure: When the shock start valve (27) is energized, the high pressure oil of the shock start accumulator (23) enters the trigger chamber and pushes the trigger sleeve; the displacement of the trigger sleeve drives the piston rod (38) to pass over the main oil inlet, so that the high pressure oil of the piston accumulator (28) enters the plug chamber; the opening of the main oil inlet increases dynamically with the increase of the displacement of the piston rod (38), promoting the acceleration of the piston rod. (b) The pressurization and control hydraulic system performs fluid management via a multi-function valve block (26): Supplying oil: The high-pressure pump unit (7) supplies oil to the piston accumulator (28); Replenishing oil: The replenishing oil accumulator (24) replenishes the anti-vacuum oil to the plug cavity through the radial fine oil channel of the trigger column; Recovering oil: When the hydraulic control two-position seven-way valve (29) is in the left position, it recovers the oil from the return oil tank / buffer tank to the drain oil tank (13). (c) Precise adjustment of inflation pressure: The gas-regulating accumulator (16) regulates the oil pressure through the proportional overflow valve (5), drives its gas chamber to connect with the gas chamber of the piston accumulator (28), synchronously adjusts the gas pressure, and absorbs the pump source pulsation to stabilize the pressure. (d) Transferring energy through an energy storage device: The piston accumulator (28) releases energy and converts it into the kinetic energy of the piston rod (38) and the impact load, which impacts the test piece at a specified speed.

2. A hydraulic control system for implementing the method of claim 1, characterized in that, include: Hydraulic shock generating device: shock actuator, the base (31) is provided with a trigger column and a trigger sleeve; hydraulic control two-position seven-way valve (29), shock start valve (27), pressure sensor (6), high frequency pressure sensor (21) and bistable positive feedback valveless flow control structure; wherein the bistable positive feedback valveless flow control structure includes a trigger sleeve provided in the base (31), one end of the trigger sleeve is provided with a uniformly distributed groove, which cooperates with the rounded arc groove of the piston rod (38) to form an oil pressure feedback channel; Hydraulic boosting and control system: including high pressure pump group (7), circulating pump group (10), oil drain recovery module, oil replenishment accumulator (24), multi-functional valve block (26), piston accumulator (28), wherein the multi-functional valve block (26) integrates accumulator charging pressure adjustment module, accumulator oil filling module, and impact reset module; Positive feedback high-speed hydraulic drive system: Through the interaction between the hydraulic shock generator and the oil circuit of the pressurization and control hydraulic system, the oil supply, replenishment and recovery closed loop of claim 1 is realized.

3. The system as described in claim 2, characterized in that: The pressurization and control hydraulic system: The high-pressure pump unit (7) adjusts the oil supply pressure through the proportional overflow valve (5); the hydraulic control two-position seven-way valve (29) performs oil recovery when in the left position and performs piston rod (38) reset when in the right position; the oil replenishment accumulator (24) replenishes the anti-vacuum oil of the plug cavity through the radial fine oil channel in the trigger column.

4. The system as described in claim 2, characterized in that: The accumulator charging pressure adjustment module includes a proportional overflow valve (5), a charging regulating accumulator (16), and a nitrogen pre-charging port (18). The gas chamber of the charging regulating accumulator (16) is connected to the gas chamber of the piston accumulator (28), and the charging pressure is adjusted in reverse by oil pressure. The accumulator oil filling module includes a gear flow meter (20) and an overflow valve (8). The volume of the gas-regulating accumulator (16) is determined by engineering calculations as a proportion of the total volume of the piston accumulator (28) to ensure that the compressed volume of the gas chamber does not exceed 3 / 4 of the total volume. The oil pressure is adjusted by the proportional overflow valve (5) to drive the gas chamber pressure balance and realize stepless adjustment of the gas pressure.

5. The system as described in claim 2, characterized in that: The hydraulic two-position seven-way valve (29) recovers oil to the drain tank (13) in the left position and cuts off the return oil passage and introduces reset oil in the right position.

6. The system as described in claim 2, characterized in that: The oil tank of the pressurization and control hydraulic system is divided into a main oil tank (1) and a drain oil tank (13). The drain oil tank (13) is located below the main oil tank (1), and the buffer oil flows back to the drain oil tank (13) by its own weight.

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