Ultrahigh-pressure hydraulic system with high-precision pressurization and pressure relief functions and control method of ultrahigh-pressure hydraulic system

Abstract

The invention provides a high-precision pressurization and decompression ultrahigh-pressure hydraulic system and a control method thereof. Comprising a motor oil pump set, a system pressure control unit and a main cylinder, and further comprises a rapid pressurization unit, a precision control unit and a pressurization and / or pressure relief control unit, the system pressure control unit is connected between the motor oil pump set and the main cylinder, and the rapid pressurization unit, the precision control unit and the pressurization and / or pressure relief control unit are connected with the main cylinder. A precision control unit is connected between the system pressure control unit and the rapid pressurization unit, and a pressurization and / or pressure relief control unit is connected between the rapid pressurization unit and the main cylinder. And the motor oil pump set, the system pressure control unit, the rapid pressurization unit, the precision control unit and the pressurization and / or pressure relief control unit are electrically connected with the controller. Pressurization and decompression of the ultrahigh pressure of the main cylinder can be accurately controlled, the displacement precision of the ultrahigh pressure press can be controlled, and large-tonnage output can be carried out.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic control systems, and in particular to an ultra-high pressure hydraulic system with high-precision pressure increase and pressure relief and a control method thereof. Background Art

[0002] With the vigorous development of industry, some products have higher requirements for processing technology, especially products made by presses, and thus the requirements for presses are getting higher and higher. However, some presses that require ultra-high pressure often require precise control of the lifting and lowering rate of the ultra-high pressure of the press and a certain position accuracy to meet the pressing process. The use of traditional press systems can no longer meet the use requirements. Because the pressure of conventional presses will not exceed 31.5MPa, in order to output ultra-high tonnage, the oil cylinder needs to be made very large, and the boost cannot be precisely controlled. The corresponding pressure reduction cannot be precisely controlled, and the traditional displacement accuracy cannot be guaranteed. In response to the above problems, the present invention proposes a high-precision super-high pressure hydraulic system with boosting and pressure relief and a control method thereof, which can not only reduce the size of the oil cylinder, but also realize the large-tonnage output of the press. At the same time, it can control the boost speed of the oil cylinder with high precision, which can not only achieve slow pressure reduction, but also ensure the position accuracy of the actuator. Summary of the invention

[0003] The purpose of the present invention is to solve the problems existing in the prior art and to propose a high-precision pressure-increasing and pressure-relieving ultra-high-pressure hydraulic system and a control method thereof.

[0004] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a high-precision super-high-pressure hydraulic system with boosting and pressure relief, comprising a motor oil pump group, a system pressure control unit and a master cylinder, wherein the motor oil pump group provides pressure oil for the system, comprises a servo motor and an oil pump, and the system pressure control unit establishes a stable system pressure for the system, comprises an electromagnetic reversing valve 1 and a cartridge valve 2, and also comprises a fast boosting unit, a precision control unit, a boosting and / or pressure relief control unit, wherein the motor oil pump group and the master cylinder are connected to the system pressure control unit, the fast boosting unit, the precision control unit and the boosting and / or pressure relief control unit A control unit, wherein a precision control unit is connected between the system pressure control unit and the rapid pressurization unit, a pressure increase and / or pressure relief control unit is connected between the rapid pressurization unit and the master cylinder, the rapid pressurization unit increases the pressure oil for the system rapidly, the precision control unit can accurately control the pressure increase and / or pressure relief of the system pressure oil, the pressure increase and / or pressure relief control unit cooperates with the precision control unit to accurately pressurize and / or relieve the master cylinder, and the motor oil pump group, the system pressure control unit, the rapid pressurization unit, the precision control unit and the pressure increase and / or pressure relief control unit are electrically connected to the controller.

[0005] Furthermore, the rapid pressure increasing unit comprises a second electromagnetic reversing valve and a second cartridge valve, the tail of the second electromagnetic reversing valve is connected to the second A port of the cartridge valve, and the second electromagnetic reversing valve and the second cartridge valve cooperate to rapidly increase the pressure of the master cylinder.

[0006] Furthermore, the precision control unit includes an accumulator and an electromagnetic reversing valve three. The accumulator access branch is also connected to a pressure sensor assembly one for monitoring the accumulator pressure. The accumulator access branch is also connected to a safety valve one for returning the pressure oil to the oil tank.

[0007] Further, the boost and / or pressure relief control unit includes a boost cylinder, a boost piston is slidably arranged inside the boost cylinder, the two ends of the boost piston are respectively A chamber and B chamber, the two ends of the A chamber and B chamber correspond to A port and B port respectively, the rapid boost unit is connected to the A port of the boost cylinder, the A port of the boost cylinder is connected to the master cylinder, a high-pressure hydraulically controlled one-way valve 1 and a high-pressure hydraulically controlled one-way valve 2 are connected between the A port of the boost cylinder and the master cylinder in sequence, the hydraulically controlled one-way valve 1 is respectively connected to the rapid boost unit and the oil tank through an electromagnetic reversing valve 4, the high-pressure hydraulically controlled one-way valve 2 is respectively connected to the rapid boost unit and the oil tank through an electromagnetic reversing valve 5, and the B port of the boost cylinder is connected to the electromagnetic reversing valve 3 through an oil circuit.

[0008] Furthermore, the A port and B port of the boost cylinder are respectively connected to pressure sensor assembly 2 and pressure sensor assembly 3 for monitoring the A port and B port; a one-way valve is connected between the A port of the boost cylinder and the rapid boost unit; and a one-way valve 2 is connected between the solenoid reversing valve 3 and the system pressure control unit.

[0009] Furthermore, a high-pressure filter is provided between the system pressure control unit and the precision control unit, and the electromagnetic reversing valve three is a high-frequency response servo proportional valve.

[0010] Furthermore, a pressure sensor assembly 4 and a safety valve 2 for returning the pressure oil to the oil tank are arranged on the oil circuit between the master cylinder and the high-pressure hydraulically controlled one-way valve.

[0011] A control method, including the above-mentioned high-precision pressure-increasing and pressure-relieving ultra-high-pressure hydraulic system, comprises the following steps: S1, the controller controls the electromagnetic reversing valve to be energized, and the pressure oil enters the rapid boosting unit and the precision control unit; S2, electromagnetic reversing valve 2 is energized, and the pressure oil enters the master cylinder through cartridge valve 2, high-pressure hydraulic control check valve 1 and check valve, and quickly increases the pressure of the master cylinder; S3, pressure sensor assembly 4 feeds back the master cylinder signal, and the high-frequency response servo proportional valve controls the boost cylinder to boost the master cylinder; S4: The pressure of the master cylinder reaches the set value and is maintained under the action of the hydraulically controlled one-way valve 1; S5, after the pressure maintenance is finished, the high-frequency response servo proportional valve controls the boost cylinder to release the pressure; S6. Pressure relief is completed, and the remaining pressure oil in the master cylinder returns to the oil tank through high-pressure hydraulic control check valve 1 and high-pressure hydraulic control check valve 2, and pressure relief is completed.

[0012] Furthermore, the S3 further includes: S31, high-frequency response servo proportional valve controls the booster cylinder to perform one and / or multiple boosts; S32, the left end of the high-frequency response servo proportional valve is energized, and the pressure oil enters the A chamber of the booster cylinder, and the booster piston returns to the bottom of the B end to prepare for slow boosting; the right end of the high-frequency response servo proportional valve is energized, and the pressure oil enters the B chamber of the booster cylinder 5 to boost the main cylinder; S33. If the booster piston of the booster cylinder reaches the A port of the booster cylinder and the master cylinder has not reached the set pressure, the left end of the high-frequency response servo proportional valve is energized, the B port of the booster cylinder is connected to the oil tank, and the system pressure oil enters the A chamber of the booster cylinder. Under the action of the pressure oil, the booster piston returns to the bottom of the B chamber and waits for secondary and / or multiple pressurizations, and returns to step S32 until the pressure value of the master cylinder meets the set requirements.

[0013] Furthermore, the S5 also includes: S51: The high-frequency response servo proportional valve controls the booster cylinder to release pressure once and / or multiple times; S52: The left end of the high-frequency response servo proportional valve is energized, the pressure oil enters chamber A, and the master cylinder begins to release pressure; S53: If the booster piston of the booster cylinder reaches the bottom of chamber B and the master cylinder still has not completed pressure relief, the right end of the high-frequency response servo proportional valve is energized, and the system pressure oil enters chamber B of the booster cylinder. The pressure oil in chamber A of the booster cylinder is energized through electromagnetic reversing valve five, and the high-pressure hydraulic control one-way valve two opens and flows back to the oil tank. The booster piston reaches the end of chamber A and waits for secondary and / or multiple pressure reliefs, returning to step S52 until the pressure value of the master cylinder is within 31.5MPa.

[0014] Compared with the existing technology, the present invention provides a high-precision pressure-increasing and pressure-relieving ultra-high-pressure hydraulic system and a control method thereof. The advantages of the present invention are: 1. It can provide ultra-high pressure for the master cylinder; 2. It can accurately control the super-high pressure boost and pressure relief of the master cylinder, and can also control the displacement accuracy of the master cylinder; 3. The structure is simple. For the same press, this solution can produce a larger output tonnage. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a framework diagram of the hydraulic principle process in the present invention; In the figure: 11, electromagnetic reversing valve 1, 12, electromagnetic reversing valve 2, 13, high-frequency response servo proportional valve, 14, electromagnetic reversing valve 4, 15, electromagnetic reversing valve 5, 21. Cartridge valve 1, 22. Cartridge valve 2, 31. Pressure sensor component 1, 32. Pressure sensor component 2, 33. Pressure sensor component 3, 34. Pressure sensor component 4, 35. Pressure sensor component 5, 4. Master cylinder, 5. Booster cylinder, 6. High-pressure filter, 7. Accumulator, 81. Safety valve one, 82. Safety valve two, 91. High-pressure hydraulically controlled one-way valve one, 92. High-pressure hydraulically controlled one-way valve two, 101. One-way valve one, 102. One-way valve two. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] Example 1, please refer to the attached figure in the specification Figure 1 As shown in, a high-precision super-high-pressure hydraulic system with pressure boosting and pressure relief includes a motor oil pump group, a system pressure control unit and a master cylinder 4. The motor oil pump group provides pressure oil for the system, including a servo motor and an oil pump. The system pressure control unit establishes a stable system pressure for the system, including an electromagnetic reversing valve 11 and a cartridge valve 21, and also includes a fast pressure boosting unit, a precision control unit, a pressure boosting and / or pressure relief control unit. The system pressure control unit, the fast pressure boosting unit, the precision control unit and the pressure boosting and / or pressure relief control unit are connected between the motor oil pump group and the master cylinder 4. A precision control unit is connected between the system pressure control unit and the rapid pressurization unit, a pressurization and / or pressure relief control unit is connected between the rapid pressurization unit and the master cylinder 4, the rapid pressurization unit increases the pressure oil for the system rapidly, the precision control unit can accurately control the pressurization and / or pressure relief of the system pressure oil, the pressurization and / or pressure relief control unit cooperates with the precision control unit to accurately pressurize and / or relieve the master cylinder 4, the motor oil pump group, the system pressure control unit, the rapid pressurization unit, the precision control unit and the pressurization and / or pressure relief control unit are electrically connected to the controller.

[0018] The rapid boost unit can quickly boost the pressure of the master cylinder 4, and the pressure of the master cylinder 4 can be quickly increased to 31.5MPa. The precision control unit and the boost and / or pressure relief control unit can accurately control the pressure oil entering the master cylinder 4. The motor oil pump group provides the system with power source pressure oil. The electromagnetic reversing valve 11 is normally not energized, and its P port and A port are connected. The pressure oil returns to the oil tank through the cartridge valve 21, and the pressure oil is unloaded to establish a stable system. The controller in this embodiment is a programmable logic controller.

[0019] Embodiment 2, as Figure 1 As shown, the rapid pressurization unit includes an electromagnetic reversing valve 12 and a cartridge valve 22. The tail of the electromagnetic reversing valve 12 is connected to the A port of the cartridge valve 22. The electromagnetic reversing valve 12 and the cartridge valve 22 cooperate to rapidly pressurize the master cylinder 4. Specifically, it is implemented as follows: after the motor oil pump group provides pressure oil to enter the system pressure control unit, when the electromagnetic reversing valve 11 is energized, the P port and the B port of the electromagnetic reversing valve 11 are connected, and the control oil at the tail of the cartridge valve 21 cannot be depressurized, so it will no longer be depressurized to establish a stable system pressure. The pressure oil enters the precision control unit or enters the boost and / or pressure relief control unit. In order to monitor the system oil circuit pressure value, a pressure sensor assembly 35 is also arranged between the system pressure control unit and the rapid pressurization unit.

[0020] When the electromagnetic reversing valve 12 is energized, the A port and T port of the electromagnetic reversing valve 12 are connected, the control oil at the tail end of the cartridge valve 22 returns to the oil tank, and the system pressure oil overcomes the spring force of the cartridge valve 22. The system pressure oil passes through the cartridge valve 22 and enters the master cylinder 4 through the oil circuit for rapid pressurization.

[0021] The precision control unit includes an accumulator 7 and an electromagnetic reversing valve 3. The branch line connected to the accumulator 7 is also connected to a pressure sensor assembly 31 for monitoring the pressure of the accumulator 7. The branch line connected to the accumulator 7 is also connected to a safety valve 81 for returning the pressure oil to the oil tank.

[0022] In this embodiment, the safety valve 81 is a high-pressure safety relief valve. If there is a power outage or a machine failure, the pressure can be released through the safety valve 81.

[0023] Embodiment 3, the boosting and / or pressure relief control unit includes a boosting cylinder 5, a boosting piston is slidably arranged inside the boosting cylinder 5, the two ends of the boosting piston are respectively A chamber and B chamber, the two ends of the A chamber and the B chamber are respectively A port and B port, the rapid boosting unit is connected to the A port of the boosting cylinder 5, the A port of the boosting cylinder 5 is connected to the master cylinder 4, a high-pressure hydraulically controlled one-way valve 1 91 and a high-pressure hydraulically controlled one-way valve 2 92 are connected between the A port of the boosting cylinder 5 and the master cylinder 4, the high-pressure hydraulically controlled one-way valve 1 91 is respectively connected to the rapid boosting unit and the oil tank through the electromagnetic reversing valve 4 14, the high-pressure hydraulically controlled one-way valve 2 92 is respectively connected to the rapid boosting unit and the oil tank through the electromagnetic reversing valve 5 15, and the B port of the boosting cylinder 5 is connected to the electromagnetic reversing valve 3 through the oil circuit.

[0024] Port A and port B of the boost cylinder 5 are also respectively connected to pressure sensor assembly 3 33 and pressure sensor assembly 2 32 for monitoring ports A and B, a one-way valve 101 is connected between port A of the boost cylinder 5 and the rapid boost unit, and a one-way valve 2 102 is connected between the electromagnetic reversing valve 3 13 and the system pressure control unit.

[0025] In this embodiment, the booster cylinder 5 is used to boost the main cylinder 4. Since the booster piston has an area difference between chamber A and chamber B, the diameter of chamber A is smaller than the diameter of chamber B, and the output pressure of chamber A is: P A =F A / A A , where P A is the output pressure of cavity A, F A is the force acting on the booster piston chamber A, A A It is the force area of ​​the booster piston in chamber A.

[0026] The output pressure of chamber B is: P B =F B / A B , where P B is the output pressure of cavity B, F B is the force acting on the booster piston chamber B, A B is the force area of ​​the booster piston in chamber B. Since the booster cylinder 5 is a closed space, F A =F B , so the output pressure of cavity A is A times the output pressure of cavity B B / A A Times, the output pressure of chamber A is the increased pressure of master cylinder 4, achieving the effect of increasing high pressure in a small area.

[0027] The pressure sensor assembly 2 32 and the pressure sensor assembly 3 33 can monitor the pressures of the A port and the B port of the boost cylinder 5 respectively.

[0028] When all the solenoid valves lose power, the high-pressure hydraulically controlled one-way valve 1 91 is used to maintain the pressure of the main cylinder 4, the high-pressure hydraulically controlled one-way valve 2 92 is used as a pressure relief switch for the A chamber of the booster cylinder 5, and the solenoid reversing valve 3 is a high-frequency response servo proportional valve 13.

[0029] Both the one-way valve 101 and the one-way valve 2 102 are high-pressure one-way valves with a pressure resistance exceeding 100 MPa. The one-way valve 101 can isolate the pressure oil between the A chamber of the booster cylinder 5 and the system oil circuit, and the one-way valve 2 102 is used to isolate the pressure oil between the accumulator 7 and the system oil circuit. The accumulator 7 is used to stabilize the pressure of the P port of the high-frequency response servo proportional valve 13 and reduce the pressure fluctuation of this section of the oil circuit. The safety valve 1 81 connected to the branch of the accumulator 7 can protect the pressure of the accumulator 7 from not exceeding 31.5 MPa to avoid damage to the accumulator 7.

[0030] In embodiment 4, a high-pressure filter 6 is provided between the system pressure control unit and the precision control unit. The high-pressure filter 6 is used to filter impurities from the system oil circuit entering the high-frequency response servo proportional valve 13, thereby preventing impurities from entering the high-frequency response servo proportional valve 13 and causing its precision to be reduced or even damaged, thereby extending its service life.

[0031] Embodiment 5: A pressure sensor assembly 4 34 and a safety valve 2 82 for returning the pressure oil to the oil tank are arranged on the oil circuit between the master cylinder 4 and the high-pressure hydraulically controlled one-way valve 1 91. The safety valve 2 82 is a manual high-pressure unloading relief valve, which is a manual safety valve. In case of power failure or machine failure, the safety valve 2 82 can be used to slowly manually release the pressure.

[0032] Embodiment 6, a control method, including the above-mentioned high-precision pressure-increasing and pressure-relieving ultra-high-pressure hydraulic system, comprises the following steps: S1, the controller controls the electromagnetic reversing valve 11 to be energized, and the pressure oil enters the rapid boosting unit and the precision control unit; S2, the electromagnetic reversing valve 2 12 is energized, and the pressure oil enters the master cylinder 4 through the cartridge valve 2 22, the check valve 101 and the high-pressure hydraulic control check valve 1 91, and quickly increases the pressure of the master cylinder 4; S3, the pressure sensor assembly 4 34 feeds back the pressure signal of the master cylinder 4, and the high-frequency response servo proportional valve 13 controls the boost cylinder 5 to boost the pressure of the master cylinder 4; S4, the pressure of the master cylinder 4 reaches the set value, and the pressure is maintained under the action of the high-pressure hydraulic control check valve 91; S5, after the pressure maintenance is finished, the high-frequency response servo proportional valve 13 controls the pressure relief of the boost cylinder 5; S6, pressure relief is completed, and the remaining pressure oil in the master cylinder 4 returns to the oil tank through the high-pressure hydraulic control one-way valve 91 and the high-pressure hydraulic control one-way valve 92, and the pressure relief is completed.

[0033] In this embodiment, the high-frequency response servo proportional valve 13 is controlled by a controller. When boosting is performed, the controller obtains the pressure signal of the pressure sensor component 434 of the master cylinder 4 and compares it with the set value to obtain an error signal, and performs closed-loop calculation on its deviation. The calculation result is used as the control signal of the high-frequency response servo proportional valve 13 to drive its valve core movement, thereby changing the amount of pressure oil entering the master cylinder 4, thereby controlling the high-precision pressure of the master cylinder 4 and achieving high-precision displacement control.

[0034] When the motor oil pump group starts, it provides pressure oil for the whole system, and the pressure oil enters the system pressure control unit. Since the electromagnetic reversing valve 11 is in the normally open position, the P port, A port, and T port of the electromagnetic reversing valve 11 are connected, and the tail of the cartridge valve 21 controls the oil to return to the oil tank. At this time, the valve cartridge valve 21 is affected by the pressure oil to overcome the spring force at the tail end of the cartridge valve 21, and the pressure oil is unloaded through the valve core of the cartridge valve 21 and returns to the oil tank.

[0035] When the electromagnetic reversing valve 11 is energized, the P port and the B port are connected, the tail control oil of the cartridge valve 21 cannot be relieved, the valve core of the cartridge valve 21 is locked, and no pressure is relieved, and a stable system pressure is established. The pressure oil enters the precision control unit or enters the boost and / or pressure relief control unit through the cartridge valve 22.

[0036] At this time, after the controller controls the electromagnetic reversing valve 212 to be energized, port A and port T are connected, the control oil at the tail end of the cartridge valve 22 returns to the oil tank, and the system pressure oil overcomes the tail spring force of the cartridge valve 22. The system pressure oil passes through the cartridge valve 22, passes through the one-way valve 101, and then passes through the hydraulic control one-way valve 91 to enter the master cylinder 4 for rapid pressurization.

[0037] Embodiment 7, the above step S3 further includes: S31, the high-frequency response servo proportional valve 13 controls the boost cylinder 5 to perform one and / or multiple boosts; S32, the left end of the high-frequency response servo proportional valve 13 is energized, the pressure oil enters the A chamber of the booster cylinder 5, and the booster piston returns to the bottom of the B end to prepare for slow boosting; the right end of the high-frequency response servo proportional valve 13 is energized, the pressure oil enters the B chamber of the booster cylinder 5 to boost the main cylinder 4.

[0038] Specifically, when the boost is performed, it is achieved as follows: when the boost pressure of the master cylinder 4 reaches a certain set value of the system (within 31.5MPa), the pressure sensor component four 34 feeds back a signal to the controller, so that the left end of the high-frequency response servo proportional valve 13 is energized, the A port and the T port of the high-frequency response servo proportional valve 13 are connected, and the B port of the boost cylinder 5 is connected to the oil tank. The system pressure oil enters the A chamber of the boost cylinder 5 through the cartridge valve 22. Under the action of the pressure oil, the boost piston of the boost cylinder 5 returns to the bottom of the B end to prepare for slow boost.

[0039] When the piston of the boost cylinder 5 returns to the bottom, the right end of the high-frequency response servo proportional valve 13 is energized, the P port and the A port of the high-frequency response servo proportional valve 13 are connected, and the pressure oil enters the B chamber of the boost cylinder 5. Due to the amplification of the relief pressure of the boost cylinder 5, the pressure entering the master cylinder 4 can reach 100MPa.

[0040] S33. If the booster piston of the booster cylinder 5 reaches the A port of the booster cylinder 5 and the master cylinder 4 has not reached the set pressure, the left end of the high-frequency response servo proportional valve 13 is energized, the B port of the booster cylinder 5 is connected to the oil tank, and the system pressure oil enters the A chamber of the booster cylinder 5. Under the action of the pressure oil, the booster piston returns to the bottom of the B chamber and waits for secondary and / or multiple pressurizations, and returns to step S32 until the pressure value of the master cylinder 4 meets the set requirements.

[0041] In the present embodiment, secondary pressurization is achieved as follows: when secondary or multiple pressurization is required, the left end of the high-frequency response servo proportional valve 13 is energized, the A port and the T port of the high-frequency response servo proportional valve 13 are connected, the B port of the boosting cylinder 5 is connected to the oil tank, the electromagnetic reversing valve 12 is energized, and the system pressure oil enters the A chamber of the boosting cylinder 5 through the cartridge valve 22. Under the action of the pressure oil, the boosting piston of the boosting cylinder 5 returns to the bottom of the B end, ready for another pressurization, the right end of the high-frequency response servo proportional valve 13 is energized, and the pressure oil enters the B chamber of the boosting cylinder 5, and the pressurization cycle is repeated.

[0042] Embodiment 8: The pressure increasing speed of the master cylinder 4 is controlled by a high-frequency response servo proportional valve 13, and the high-frequency response servo proportional valve 13 is controlled by a controller. When the pressure is increased, the controller obtains the pressure signal of the pressure sensor component 434 of the master cylinder 4 and compares it with the set value to obtain an error signal, and performs a closed-loop calculation on its deviation. The calculation result is used as the control signal of the high-frequency response servo proportional valve 13 to drive its valve core movement, change the hydraulic oil entering the master cylinder 4, thereby controlling the high-precision pressure of the master cylinder 4 and realizing high-precision displacement control.

[0043] In this embodiment, the pressure increasing speed of the master cylinder 4 can reach 0.002 MPa / min, and the displacement accuracy can reach 0.005 mm / s.

[0044] Until the pressure of the master cylinder 4 reaches the set pressure, the boost cylinder 5 stops boosting, all solenoid valves lose power, and the system pressure oil returns to the oil tank from the cartridge valve 21. The pressure of the master cylinder 4 is maintained under the action of the high-pressure hydraulic control one-way valve 91.

[0045] Embodiment 9, the above step S5 further includes: S51: The high-frequency response servo proportional valve 13 controls the boost cylinder 5 to release pressure once and / or multiple times; S52: The left end of the high-frequency response servo proportional valve 13 is energized, the pressure oil enters the A chamber, and the master cylinder 4 starts to release pressure; S53: If the booster piston of the booster cylinder 5 reaches the bottom of the B chamber and the master cylinder 4 has not yet completed the pressure relief, the right end of the high-frequency response servo proportional valve 13 is energized, and the system pressure oil enters the B chamber of the booster cylinder 5. The pressure oil in the A chamber of the booster cylinder 5 is energized through the electromagnetic reversing valve 5 15, and the high-pressure hydraulic control one-way valve 2 92 opens and flows back to the oil tank. The booster piston reaches the end of the A chamber and waits for secondary and / or multiple pressure reliefs, returning to step S52 until the pressure value of the master cylinder 4 is within 31.5 MPa.

[0046] Because the pressure in the master cylinder is very high, the pressurized oil cannot be directly injected into the oil tank through the high-pressure hydraulically controlled one-way valve 91 and the high-pressure hydraulically controlled one-way valve 92. This will damage the oil pipe and the high-pressure hydraulically controlled one-way valve 91 and the high-pressure hydraulically controlled one-way valve 92. Only by gradually releasing the pressure through the booster cylinder 5 can the stability of the pressure in the pipeline be guaranteed.

[0047] The pressure relief of the master cylinder 4 is specifically achieved as follows: when the pressure maintenance is completed, the electromagnetic reversing valve 4 14 is energized, the high-pressure hydraulic control one-way valve 1 91 is opened, and the pressure oil of the master cylinder 4 enters the A chamber of the booster cylinder 5. The left end of the high-frequency response servo proportional valve 13 is energized, and the A port and the T port are connected and lead to the oil tank. At this time, the controller compares the master cylinder 4 pressure value detected by the pressure sensor component 4 34 with the set value, controls the movement of the valve core of the high-frequency response servo proportional valve 13, and controls the return oil flow from the A port to the T port of the high-frequency response servo proportional valve 13, thereby achieving high-precision control of the pressure reduction. The booster piston moves from the A chamber to the B chamber, and the volume of the A chamber gradually increases, and the compressed hydraulic oil of the master cylinder 4 is gradually released, and the pressure of the master cylinder 4 is gradually reduced.

[0048] When the booster piston of the booster cylinder 5 moves to a certain position toward the B chamber, the electromagnetic reversing valve 4 14 loses power, the high-pressure hydraulic control check valve 1 91 closes, the master cylinder 4 continues to maintain pressure, and the left end of the high-frequency response servo proportional valve 13 continues to be powered. The booster piston will still move from the A chamber to the B chamber under the action of the compressed pressure oil. When the booster piston reaches the bottom of the B chamber of the booster cylinder 5, the electromagnetic reversing valve 5 15 is powered, the high-pressure hydraulic control check valve 2 92 is opened, and the right end of the high-frequency response servo proportional valve 13 is powered. The B chamber of the booster cylinder 5 enters oil, pushing the booster piston to move toward the A chamber, and the pressure oil in the A chamber flows back to the oil tank through the high-pressure hydraulic control check valve 2 92. After the booster piston returns to the top of chamber A, if the pressure relief is not completed, wait for the secondary pressure relief, and the electromagnetic reversing valve four 14 is still energized, the high-pressure hydraulic control one-way valve one 91 is opened, and the left end of the high-frequency response servo proportional valve 13 is energized. The A port and T port of the high-frequency response servo proportional valve 13 are connected and lead to the oil tank, and the pressure oil of the master cylinder 4 enters the A chamber of the booster cylinder 5. The pressure oil in chamber A flows back to the oil tank through the high-pressure hydraulic control one-way valve two 92. The above steps are repeated until the pressure of the master cylinder 4 is within 31.5MPa. Finally, the electromagnetic reversing valve four 14 and the electromagnetic reversing valve five 15 are energized, and the remaining pressure oil of the master cylinder 4 returns to the oil tank through the high-pressure hydraulic control one-way valve one 91 and the high-pressure hydraulic control one-way valve two 92, and the pressure relief is completed.

[0049] In this embodiment, in the high-precision pressure control, the master cylinder 4 pressure control accuracy calculation formula is: ΔP=K p ·(P sct -P actual ), where ΔP represents the pressure deviation, K p is the proportional gain, P sct Indicates the set pressure, P actual Indicates the actual pressure. The relationship between the valve core displacement and flow rate of the high-frequency response servo proportional valve 13 can be expressed as: Q=K v ⋅(ΔP) n , where Q is the flow rate, K v is the flow coefficient of the valve, ΔP is the calculated pressure deviation, and n is an index related to the valve characteristics; The calculation formula of the displacement accuracy of the master cylinder 4 is expressed as: ,and ,so , where V represents the speed of the piston, Q represents the flow rate, A represents the piston area of ​​the master cylinder 4, and dt represents the interval time, and the displacement S of the master cylinder 4 can be calculated.

[0050] To sum up, the above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A high-precision super-high pressure hydraulic system for boosting and depressurizing, comprising a motor oil pump group, a system pressure control unit and a master cylinder, wherein the motor oil pump group provides pressure oil for the system and comprises a servo motor and an oil pump, and the system pressure control unit establishes a stable system pressure for the system and comprises an electromagnetic reversing valve (11) and a cartridge valve (21), characterized in that: It also includes a rapid pressure increasing unit, a precision control unit, and a pressure increasing and / or pressure reducing control unit. The motor oil pump group and the master cylinder (4) are connected to a system pressure control unit, the rapid pressure increasing unit, the precision control unit and the pressure increasing and / or pressure reducing control unit. The system pressure control unit and the rapid pressure increasing unit are connected to a precision control unit. The rapid pressure increasing unit and the master cylinder (4) are connected to a pressure increasing and / or pressure reducing control unit. The precision control unit can accurately control the pressure increasing and / or pressure reducing of the system pressure oil. The pressure increasing and / or pressure reducing control unit cooperates with the precision control unit to accurately pressure increasing and / or pressure reducing the master cylinder (4). It also includes a controller. The motor oil pump group, the system pressure control unit, the rapid pressure increasing unit, the precision control unit and the pressure increasing and / or pressure reducing control unit are electrically connected to the controller.

2. A high-precision pressure-increasing and pressure-relieving ultra-high-pressure hydraulic system according to claim 1, characterized in that: The rapid pressure increasing unit comprises a second electromagnetic reversing valve (12) and a second cartridge valve (22), the tail of the second electromagnetic reversing valve (12) being connected to a port A of the second cartridge valve (22), and the second electromagnetic reversing valve (12) and the second cartridge valve (22) cooperate to rapidly increase the pressure of the master cylinder (4).

3. The high-precision super-high pressure hydraulic system for boosting and releasing pressure according to claim 1, characterized in that: The precision control unit comprises an accumulator (7) and a third electromagnetic reversing valve; the accumulator (7) access branch is also connected to a pressure sensor assembly (31) for monitoring the pressure of the accumulator (7); the accumulator (7) access branch is also connected to a safety valve (81) for returning pressure oil to the oil tank.

4. The high-precision pressure-increasing and pressure-relieving ultra-high-pressure hydraulic system according to claim 1, characterized in that: The boost and / or pressure relief control unit comprises a boost cylinder (5), a boost piston is slidably arranged inside the boost cylinder (5), the two ends of the boost piston are respectively an A chamber and a B chamber, the two ends of the A chamber and the B chamber correspond to an A port and a B port respectively, the rapid boost unit is connected to the A port of the boost cylinder (5), the A port of the boost cylinder (5) is connected to the master cylinder (4), a high-pressure hydraulically controlled check valve 1 (91) and a high-pressure hydraulically controlled check valve 2 (92) are connected in sequence between the A port of the boost cylinder (5) and the master cylinder (4), the hydraulically controlled check valve 1 (91) is respectively connected to the rapid boost unit and the oil tank through an electromagnetic reversing valve 4 (14), the high-pressure hydraulically controlled check valve 2 (92) is respectively connected to the rapid boost unit and the oil tank through an electromagnetic reversing valve 5 (15), and the B port of the boost cylinder (5) is connected to the electromagnetic reversing valve 3 through an oil circuit.

5. The high-precision pressure-increasing and pressure-relieving ultra-high-pressure hydraulic system according to claim 4, characterized in that: The A port and B port of the boost cylinder (5) are also respectively connected to a pressure sensor assembly three (33) and a pressure sensor assembly two (32) for monitoring the A port and the B port, a one-way valve one (101) is connected between the A port of the boost cylinder (5) and the rapid boost unit, and a one-way valve two (102) is connected between the electromagnetic reversing valve three and the system pressure control unit.

6. The high-precision pressure-increasing and pressure-relieving ultra-high-pressure hydraulic system according to claim 3, characterized in that: The oil circuit connected to the precision control unit is also provided with a high-pressure filter (6), and the electromagnetic reversing valve three is a high-frequency response servo proportional valve (13).

7. The high-precision pressure-increasing and pressure-relieving ultra-high-pressure hydraulic system according to claim 1, characterized in that: A pressure sensor assembly 4 (34) and a safety valve 2 (82) for returning the pressure oil to the oil tank are arranged on the oil circuit between the master cylinder (4) and the high-pressure hydraulically controlled one-way valve 1 (91).

8. A control method, comprising a high-precision pressure-increasing and pressure-relieving ultra-high-pressure hydraulic system as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: S1, the controller controls the electromagnetic reversing valve 1 (11) to be energized, and the pressure oil enters the rapid boost unit and the precision control unit; S2, the electromagnetic reversing valve 2 (12) is energized, and the pressure oil enters the master cylinder (4) through the cartridge valve 2 (22), the check valve (101) and the high-pressure hydraulic control check valve 1 (91), thereby quickly increasing the pressure of the master cylinder (4); S3, pressure sensor assembly four (34) feeds back the pressure signal of the master cylinder (4), and the high-frequency response servo proportional valve (13) controls the boost cylinder (5) to boost the pressure of the master cylinder (4); S4, the pressure of the master cylinder (4) reaches the set value, and the pressure is maintained under the action of the high-pressure hydraulically controlled one-way valve 1 (91); S5, after the pressure maintenance is finished, the high-frequency response servo proportional valve (13) controls the pressure relief of the boost cylinder; S6. Pressure relief is completed. The remaining pressure oil in the master cylinder (4) returns to the oil tank through the high-pressure hydraulic control check valve 1 (91) and the high-pressure hydraulic control check valve 2 (92). Pressure relief is completed.

9. A control method according to claim 8, characterized in that: The S3 further includes: S31, a high-frequency response servo proportional valve (13) controls the boost cylinder (5) to perform one and / or multiple boosts; S32, the left end of the high-frequency response servo proportional valve (13) is energized, and the pressure oil enters the A chamber of the booster cylinder, and the booster piston returns to the bottom of the B chamber to prepare for slow pressure increase; the right end of the high-frequency response servo proportional valve (13) is energized, and the pressure oil enters the B chamber of the booster cylinder (5) to increase the pressure for the main cylinder (4); S33. If the booster piston of the booster cylinder (5) reaches the A port of the booster cylinder (5) and the master cylinder (4) has not yet reached the set pressure, the left end of the high-frequency response servo proportional valve (13) is energized, the B port of the booster cylinder is connected to the oil tank, and the system pressure oil enters the A chamber of the booster cylinder (5). Under the action of the pressure oil, the booster piston returns to the bottom of the B chamber and waits for secondary and / or multiple pressurizations, and returns to step S32 until the pressure value of the master cylinder (4) meets the set requirements.

10. A control method according to claim 8, characterized in that: The S5 also includes: S51: The high-frequency response servo proportional valve (13) controls the boost cylinder (5) to release pressure once and / or multiple times; S52: The left end of the high-frequency response servo proportional valve (13) is energized, the pressure oil enters chamber A, and the master cylinder (4) begins to release pressure; S53: If the booster piston of the booster cylinder (5) reaches the bottom of chamber B and the master cylinder (4) has not yet completed pressure relief, the right end of the high-frequency response servo proportional valve (13) is energized, and the system pressure oil enters chamber B of the booster cylinder (5). The pressure oil in chamber A of the booster cylinder (5) is energized through the electromagnetic reversing valve five (15), and the high-pressure hydraulic control check valve two (92) opens and flows back to the oil tank. The booster piston reaches the end of chamber A and waits for secondary and / or multiple pressure reliefs, returning to step S52 until the pressure value of the master cylinder (4) is within 31.5 MPa.

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