Hydraulic system capable of continuously and stably outputting ultra-high pressure and large flow and control method thereof

Abstract

The present invention discloses a hydraulic system capable of continuously and stably outputting ultra-high pressure and large flow and a control method thereof. The hydraulic system comprises: n hydraulic modules, each of which comprises a booster oil cylinder, the stroke of the booster oil cylinder is m, the initial positions of the n booster oil cylinders are 0, m / n, ..., (n-1)m / n respectively; the movement speeds of the n booster oil cylinders are V1, V2, ..., V n The effective area of ​​the booster cylinder is X, and the flow rate output by the hydraulic system is Q=X(V1+V2+···+V n ), where V1+V2+···+V n The sum of is the same, n ≥ 2. Through the coordinated work of n hydraulic modules and the regulation of the movement speed and starting position of n booster cylinders, the hydraulic system can continuously and stably output ultra-high pressure and large flow.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic systems, and in particular to a hydraulic system capable of continuously and stably outputting ultra-high pressure and large flow, and a control method thereof. Background Art

[0002] In existing engineering machinery that relies on hydraulic drive, the pressure of the hydraulic system is determined by the load of the hydraulic actuator. When the load of the hydraulic actuator is small, the pressure of the hydraulic system is also small. When the load of the hydraulic actuator increases, the pressure of the hydraulic system increases accordingly. However, when the load of the hydraulic actuator exceeds the maximum pressure that the hydraulic system can provide, the hydraulic system cannot make the hydraulic actuator operate normally. Based on this situation, the usual practice is to configure a booster cylinder in the hydraulic system to increase the output pressure of the hydraulic system.

[0003] With the continuous development of technology, some application scenarios require the hydraulic system to continuously and stably output ultra-high pressure and large flow. Although the use of booster cylinders can increase the output pressure and output flow of the hydraulic system, it cannot meet the requirements of "continuous and stable output" of the hydraulic system. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a hydraulic system and a control method thereof that can continuously and stably output ultra-high pressure and large flow, which can meet the demand for continuous and stable output of ultra-high pressure and large flow.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a hydraulic system capable of continuously and stably outputting ultra-high pressure and large flow, comprising: n hydraulic modules, each of which comprises a booster cylinder, the stroke of the booster cylinder is m, the initial positions of the n booster cylinders are 0, m / n, ..., (n-1)m / n respectively; the movement speeds of the n booster cylinders are V1, V2, ..., V n The effective area of ​​the booster cylinder is X, and the flow rate output by the hydraulic system is Q=X(V1+V2+···+V n ), where V1+V2+···+V n The sum of is the same, n≥2.

[0006] Furthermore, within a movement cycle of the boost cylinder, the movement states of the boost cylinder include: acceleration movement, deceleration movement, uniform speed movement and return movement; at the same moment, at least two of the movement states of the n boost cylinders are different movement states.

[0007] Furthermore, the hydraulic module also includes: a displacement sensor and a servo control module, wherein the displacement sensor is used to monitor the position of the piston of the hydraulic cylinder, and the servo control module is used to control the movement speed of the booster cylinder.

[0008] Furthermore, the booster cylinder includes: a cylinder barrel, a piston and a piston rod, the piston is fixedly connected to the piston rod, an A1 chamber is formed between the left end of the piston and the cylinder barrel, an A2 chamber is formed between the right end of the piston and the cylinder barrel, a B1 chamber is formed between the left end of the piston rod and the cylinder barrel, and a B2 chamber is formed between the right end of the piston rod and the cylinder barrel; wherein, the ratio of the effective area of ​​the A1 chamber to the effective area of ​​the B2 chamber is a, and the ratio of the effective area of ​​the B1 chamber to the effective area of ​​the A2 chamber is 1 / a.

[0009] Furthermore, the hydraulic module also includes: solenoid valve 1, solenoid valve 2, solenoid valve 3, solenoid valve 4, solenoid valve 5, solenoid valve 6, solenoid valve 7 and solenoid valve 8, the solenoid valve 1 and solenoid valve 5 are both connected to the B1 cavity, the solenoid valve 2 and solenoid valve 6 are both connected to the A1 cavity, the solenoid valve 3 and solenoid valve 7 are both connected to the A2 cavity, and the solenoid valve 4 and solenoid valve 8 are both connected to the B2 cavity.

[0010] Furthermore, the cylinder includes: a main body, a first cover shell and a second cover shell, the first cover shell and the second cover shell are detachably connected to the left and right ends of the main body respectively, a B1 cavity is formed between the first cover shell and the piston rod, and a B2 cavity is formed between the second cover shell and the piston rod.

[0011] The present invention also provides a control method for a hydraulic system capable of continuously and stably outputting ultra-high pressure and large flow, comprising the following steps: setting the initial positions of the 1st to nth booster cylinders to 0, m / n, ..., (n-1)m / n, respectively; the n booster cylinders move to the right at the same time, the nth booster cylinder moves to the rightmost end first and returns, and the 1st booster cylinder moves to the rightmost end last and returns; at each moment, the sum of the movement speeds of the n booster cylinders is V1+V2+···+V n are the same, so that the flow and pressure output by the hydraulic system that can continuously and stably output ultra-high pressure and large flow are stable at every moment.

[0012] Furthermore, assuming that the pressure output by the low-pressure oil source is P, and the average flow rate delivered by the low-pressure oil source to each hydraulic cylinder is q; when the hydraulic system that can continuously and stably output ultra-high pressure and large flow is in an ultra-high pressure and large flow condition, solenoid valve 2, solenoid valve 3, and solenoid valve 8 are powered on and opened, and solenoid valve 1, solenoid valve 4, solenoid valve 5, solenoid valve 6, and solenoid valve 7 are powered off and closed, and the low-pressure oil enters the A1 chamber of the booster cylinder through the solenoid valve 2, the piston rod of the booster cylinder moves to the right, the B1 chamber of the booster cylinder is replenished with oil, the A2 chamber is returned to oil through the solenoid valve 3, and the B2 chamber pressurizes the low-pressure oil and then flows into the A station of the actuator through the solenoid valve 8. The continuous and stable output pressure of the A station is P*a, and the output flow is qn / a.

[0013] Furthermore, assuming that the pressure output by the low-pressure oil source is P, and the average flow rate delivered by the low-pressure oil source to each hydraulic cylinder is q; when the hydraulic system that can continuously and stably output ultra-high pressure and large flow is in a flow-increasing condition, solenoid valve one, solenoid valve four, and solenoid valve seven are energized and opened, and solenoid valve two, solenoid valve three, solenoid valve five, solenoid valve six, and solenoid valve eight are de-energized and closed, and the low-pressure oil enters the B1 chamber of the boosting cylinder through the solenoid valve one, the piston rod of the boosting cylinder moves to the right, the A1 chamber of the boosting cylinder is replenished with oil, and the B2 chamber returns oil through the solenoid valve four. The A2 chamber pressurizes the low-pressure oil and then flows into the B station of the actuator through the solenoid valve seven. The continuous and stable output pressure of the B station is P / a, and the output flow is q*n*a.

[0014] Furthermore, within one movement cycle of the boost cylinder, the movement state of the piston rod changes between acceleration movement, deceleration movement, uniform movement and return movement. Since the initial positions of the piston rods of the n boost cylinders are different, the movement states of the n boost cylinders at the same moment will be different, so as to ensure that the sum of the movement speeds of the n boost cylinders at each moment remains stable.

[0015] The beneficial effect of the present invention is that the present invention can realize the continuous and stable output of ultra-high pressure and large flow by the hydraulic system through the improvement of the system structure, the coordinated work of n hydraulic modules, and the regulation of the movement speed and starting position of n booster cylinders. When one of the booster cylinders returns from the end point to the starting point, the system output is kept stable by regulating the speed of the remaining n-1 booster cylinders. The speed regulation is shared by the remaining n-1 booster cylinders and will not be concentrated on only one booster cylinder. The booster cylinder is less impacted, which is beneficial to extending the service life of the booster cylinder. The coordinated cooperation of n booster cylinders enables the hydraulic system to output ultra-high pressure and large flow. The size of each booster cylinder does not need to be made very large, which is beneficial to reducing manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0017] Figure 1 It is a schematic diagram of the hydraulic system of the present invention.

[0018] Figure 2 It is a cross-sectional view of the hydraulic cylinder of the present invention.

[0019] Figure 3 It is a structural schematic diagram of the hydraulic module of the present invention.

[0020] Figure 4 It is a schematic diagram of the change of the movement speed of the four hydraulic cylinders of the present invention over time.

[0021] In the figure: 1. booster cylinder; 101. piston; 102. cylinder; 103. piston rod; 104. sealing ring; 1021. main body; 1022. first cover shell; 1023. second cover shell; 10211. main shell; 10212. connecting shell; 2. solenoid valve one; 3. solenoid valve two; 4. solenoid valve three; 5. solenoid valve four; 6. solenoid valve five; 7. solenoid valve six; 8. solenoid valve seven; 9. solenoid valve eight; 10. one-way valve one; 11. one-way valve two; 12. one-way valve three; 13. one-way valve four; 14. servo valve; 15. one-way valve five; 16. one-way valve six; 17. one-way valve seven; 18. one-way valve eight. DETAILED DESCRIPTION

[0022] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0023] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0024] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] like Figures 1 to 3 As shown, the hydraulic system of the present invention comprises: n hydraulic modules, each of which comprises a booster cylinder 1, the stroke of the booster cylinder 1 is m, the initial positions of the n booster cylinders 1 are 0, m / n, ..., (n-1)m / n respectively; the movement speeds of the n booster cylinders 1 are V1, V2, ..., V n The effective area of ​​the booster cylinder 1 is X, and the flow rate output by the hydraulic system is Q=X(V1+V2+···+V n ), where V1+V2+···+V n The sum of is the same, n≥2.

[0026] By ensuring that the sum of the movement speeds of the n booster cylinders 1 at any time is a constant, the flow rate Q output by the hydraulic system is a constant. , C represents the flow coefficient, d represents the orifice diameter, ρ represents the liquid density, when the flow Q is a constant, the pressure difference It is also a constant value, that is, the output pressure of the hydraulic system is stable.

[0027] The hydraulic system of the present invention mainly includes two working conditions, one is the ultra-high pressure and large flow working condition, and the other is the increased flow (also belongs to the large flow) working condition. For example, the ultra-high pressure and large flow working condition requires the hydraulic system output pressure to be not less than 70MPa and the output flow to be not less than 2000L / min; the increased flow working condition requires the hydraulic system output flow to be not less than 8000L / min and the output pressure to be not less than 17MPa.

[0028] It should be noted that the method for increasing pressure and flow in the prior art is to set a booster cylinder 1 in the hydraulic system, and increase the pressure in the booster chamber by changing the position of the piston rod 103 in the booster cylinder 1, thereby outputting high-pressure liquid. In the existing solution, when the piston rod 103 returns from the end position to the starting position, the output pressure and flow of the booster cylinder 1 will suddenly decrease, and the booster cylinder 1 needs to start moving again from the starting position to re-increase the pressure, which causes the output pressure / flow of the hydraulic system to not meet the working condition requirements for a certain period of time, that is, the output of the hydraulic system will show greater volatility and cannot meet the requirements of continuous and stable output.

[0029] The present invention sets n (n≥2) hydraulic modules, each of which includes a booster cylinder 1. The n hydraulic modules work together. When the piston rod 103 of one of the booster cylinders 1 returns from the end position to the starting position, the remaining n-1 booster cylinders 1 can ensure the stability of the total output pressure and output flow by adjusting the movement speed.

[0030] Specifically, the hydraulic module also includes: a displacement sensor, a servo control module (including a servo valve), a flow sensor, a pressure sensor, an electrical control module (including a PLC, an acquisition card, a driver, an industrial computer, etc.) and a low-pressure pump group. The displacement sensor is used to monitor the position of the piston 101 of the hydraulic cylinder 1, the servo control module is used to control the movement speed of the booster cylinder 1, the low-pressure pump group is used to provide initial power for the hydraulic system, the pressure sensor is used to monitor the output pressure of the booster cylinder 1, the flow sensor is used to monitor the output flow of the booster cylinder 1, and the acquisition card can collect data monitored by each sensor.

[0031] Specifically, the booster cylinder 1 includes: a cylinder 102, a piston 101 and a piston rod 103. The piston 101 is fixedly connected to the piston rod 103. An A1 chamber is formed between the left end of the piston 101 and the cylinder 102, an A2 chamber is formed between the right end of the piston 101 and the cylinder 102, a B1 chamber is formed between the left end of the piston rod 103 and the cylinder 102, and a B2 chamber is formed between the right end of the piston rod 103 and the cylinder 102. Among them, the B1 chamber, the A1 chamber, the A2 chamber, and the B2 chamber are isolated by a sealing ring 104. Before use, the B1 chamber, the A1 chamber, the A2 chamber, and the B2 chamber are first filled with oil and exhausted, so that the piston rod 103 moves to the set initial position. Among them, the ratio of the effective area of ​​the A1 chamber to the effective area of ​​the B2 chamber is a, and the ratio of the effective area of ​​the B1 chamber to the effective area of ​​the A2 chamber is 1 / a. The output force of the booster cylinder 1 = pressure × effective effective area.

[0032] When the hydraulic system is in an ultra-high pressure condition, oil enters the A1 chamber of the boost cylinder 1 and oil exits the B2 chamber. When oil enters the A1 chamber, the piston rod 103 is pushed to the right, and the ratio of the effective area of ​​the A1 chamber to the effective area of ​​the B2 chamber is a. The oil pressure output by the low-pressure pump group is P, and the oil pressure output by the B2 chamber is P*a. The B2 chambers of the n boost cylinders 1 are all connected to the actuator, which can ensure that the pressure output to the actuator remains P*a. The average flow rate delivered by the low-pressure pump group to each boost cylinder 1 is q, the flow rate output by one boost cylinder 1 is q / a, and the total flow rate output by n boost cylinders 1 is q*n / a.

[0033] When the hydraulic system is in the flow-increasing condition, oil enters the B1 chamber of the booster cylinder 1 and oil exits the A2 chamber. When oil enters the B1 chamber, the piston rod 103 is pushed to the right. The ratio of the effective area of ​​the B1 chamber to the effective area of ​​the A2 chamber is 1 / a. The oil pressure output by the low-pressure pump group is P, and the oil pressure output by the B2 chamber is P / a. The B2 chambers of the n booster cylinders 1 are all connected to the actuator, which can ensure that the pressure output to the actuator remains at P / a. The average flow delivered by the low-pressure pump group to each booster cylinder 1 is q, the flow output by one booster cylinder 1 is q*a, and the total flow output by n booster cylinders 1 is q*n*a.

[0034] It should be noted that the hydraulic module of the present invention can realize the control switching of ultra-high pressure working condition and increased flow working condition through the same set of structures. Conventional boosting cylinder 1 generally only has two chambers, one chamber is the oil chamber, and the other chamber is the boosting chamber. When the oil in the oil chamber pushes the piston rod to move toward the boosting chamber, the boosting demand can be achieved. The conventional boosting cylinder structure can only meet the boosting demand, and cannot meet the boosting and flow increasing conditions at the same time. However, a group of ultra-high pressure and large flow hydraulic components have emerged, and these hydraulic components need to be able to provide continuous and stable output when in use. For example, hydraulic equipment such as hydraulic test benches and forging presses cannot have large fluctuations in ultra-high pressure and large flow during operation, and need to work all the time. Based on this, the present invention designs a hydraulic system that can not only meet the ultra-high pressure and increased flow working conditions, but also meet the requirements of "continuous and stable output", killing two birds with one stone.

[0035] Specifically, the cylinder 102 includes: a main body 1021, a first cover shell 1022 and a second cover shell 1023. The first cover shell 1022 and the second cover shell 1023 are detachably connected to the left and right ends of the main body 1021, respectively. A B1 cavity is formed between the first cover shell 1022 and the piston rod 103, and a B2 cavity is formed between the second cover shell 1023 and the piston rod 103. The main body 1021 includes a main housing 10211 and two connecting housings 10212 connected to the left and right ends of the main housing 10211, respectively. The inner diameter of the main housing 10211 is larger than the inner diameter of the connecting housing 10212. The first cover shell 1022 is connected to the connecting housing 10212 at the left end by screws, and the second cover shell 1023 is connected to the connecting housing 10212 at the right end by screws. Since the B1 chamber and the B2 chamber are ultra-high pressure chambers, they are easy to be damaged. The first housing 1022 and the second housing 1023 are designed to be detachable, which is convenient for the replacement of the first housing 1022 and the second housing 1023. The inner diameters of the first housing 1022, the second housing 1023 and the connecting housing 10212 are the same and smaller than the inner diameter of the main housing 10211. The piston 101 is located in the main housing 10211 and divides the interior of the main housing 10211 into the A1 chamber and the A2 chamber. As the piston 101 moves left and right in the main housing 10211, the sizes of the A1 chamber and the A2 chamber will change. The effective areas of the A1 chamber and the A2 chamber are the same. The left end of the piston rod 103 can extend into the first housing 1022, and the right end of the piston rod 103 can extend into the second housing 1023. The total length of the cylinder 102 is greater than the total length of the piston rod 103, and the piston rod 103 moves as the piston 101 moves left and right. The movable stroke of the piston 101 is substantially equal to the length of the main housing 10211 minus the thickness of the piston 101. When the piston 101 is located at the leftmost end of the main housing 10211, the coordinate position of the piston rod 103 is 0. As the piston rod 103 moves to the right, the coordinate position of the piston rod 103 gradually increases. When the piston 101 moves to the rightmost end of the main housing 10211, the coordinate position of the piston rod 103 is m.

[0036] When the n boosting cylinders 1 of the present invention are in the initial state, the coordinate positions of the piston rods 103 are 0, m / n, ..., (n-1)m / n respectively. When the piston rods 103 of the n boosting cylinders 1 start to move at the same time, the piston rod 103 of the nth boosting cylinder 1 will first move to the rightmost end and then return to the leftmost end. When one of the boosting cylinders 1 is in the return motion, the output pressure and output flow of the hydraulic system will drop sharply. In order to improve this problem, during the return motion of a certain boosting cylinder 1, the movement speed of the remaining n-1 boosting cylinders 1 is adjusted so that V1+V2+···+V nThe sum of the pressures of the piston rods 103 of the n booster cylinders 1 remains stable. That is to say, by setting the initial positions of the piston rods 103 of the n booster cylinders 1, only one booster cylinder 1 will perform a return motion at the same time, and by regulating the movement speeds of the piston rods 103 of the remaining n-1 booster cylinders 1, the output pressure and output flow of the hydraulic system can be kept stable. The movement of the piston rod 103 of each booster cylinder 1 from its respective starting position to its starting position is a movement cycle, and the duration of the movement cycles of the n booster cylinders 1 is the same.

[0037] It should be noted that the number of booster cylinders 1 of the present invention is preferably n≥3. As mentioned above, only one booster cylinder 1 is set. When the booster cylinder 1 returns from the end point to the starting point, the output pressure and output flow of the hydraulic system will drop sharply, which cannot meet the requirement of "continuous and stable output". When two booster cylinders 1 are set, by setting the initial positions of the two booster cylinders 1, when one of the booster cylinders 1 returns from the end point to the starting point, it is necessary to increase the movement speed of the other booster cylinder 1 to stabilize the output of the system. Since the system output drops sharply, the movement of the other booster cylinder 1 will be very large, which will cause the impact of the booster cylinder 1 when it reaches the end point to be large, and the booster cylinder 1 is easily damaged. Secondly, the two booster cylinders 1 need to output ultra-high pressure and large flow, and the size of the booster cylinder 1 needs to be made very large, which will significantly increase the manufacturing cost. Furthermore, although the two booster cylinders can also meet the output of ultra-high pressure and large flow through speed control, the pulsation of their output is high and the stability is poor. Based on this, the present invention preferably sets the number of booster cylinders 1 to n≥3, which has the following advantages:

[0038] 1. When one of the boost cylinders 1 returns from the end point to the starting point, the system output is kept stable by adjusting the speed of the remaining n-1 boost cylinders 1. The speed control is shared by the remaining n-1 boost cylinders 1 and will not be concentrated on only one boost cylinder 1. The boost cylinder 1 is less impacted, which is beneficial to extending the service life of the boost cylinder 1.

[0039] Second, the n booster cylinders 1 cooperate with each other to enable the hydraulic system to output ultra-high pressure and large flow, and the size of each booster cylinder 1 does not need to be made very large, which is conducive to reducing manufacturing costs.

[0040] 3. The n booster cylinders 1 cooperate with each other to continuously and stably output ultra-high pressure and large flow, with small pulsation and good stability.

[0041] Specifically, the hydraulic module further includes: solenoid valve 1 2, solenoid valve 2 3, solenoid valve 3 4, solenoid valve 4 5, solenoid valve 5 6, solenoid valve 6 7, solenoid valve 7 8 and solenoid valve 8 9. Solenoid valve 1 2 and solenoid valve 5 6 are connected to chamber B1, solenoid valve 2 3 and solenoid valve 6 7 are connected to chamber A1, solenoid valve 3 4 and solenoid valve 7 8 are connected to chamber A2, solenoid valve 4 5 and solenoid valve 8 9 are connected to chamber B2. Solenoid valve 5 6 is connected to check valve 1 10, solenoid valve 6 7 is connected to check valve 2 11, solenoid valve 7 8 is connected to check valve 3 12, solenoid valve 8 9 is connected to check valve 4 13. Check valve 1 10, check valve 2 11, check valve 3 12 and check valve 4 13 are used to limit the flow direction of oil to prevent the oil in the actuator from flowing back into the booster cylinder 1. The low-pressure oil source is connected to the P port of the servo valve 14, the T port of the servo valve 14 is connected to the oil tank, the A port of the servo valve 14 is connected to the solenoid valve 1 2 and the solenoid valve 2 3, and the B port of the servo valve 14 is connected to the solenoid valve 3 4 and the solenoid valve 4 5. A check valve 5 15 and a check valve 6 16 are connected between the B1 chamber and the B2 chamber, and the inlet of the check valve 5 15 is connected to the inlet of the check valve 16 to prevent the oil from flowing between the B1 chamber and the B2 chamber. A check valve 7 17 and a check valve 8 18 are connected between the A1 chamber and the A2 chamber, and the inlet of the check valve 7 17 is connected to the inlet of the check valve 8 18 to prevent the oil from flowing between the A1 chamber and the A2 chamber. According to different working conditions, the electrical control module opens different solenoid valves to achieve different control requirements.

[0042] For example, when in the ultra-high pressure working condition, the solenoid valve 23, the solenoid valve 34 and the solenoid valve 89 are powered on and opened, and the other solenoid valves are closed. In this way, the low-pressure oil enters the A1 chamber through the servo valve 14 and the solenoid valve 23 to push the piston 101 to move to the right. At this time, the oil in the A2 chamber returns to the oil tank through the solenoid valve 34, and the oil in the B2 chamber is squeezed and enters the A position of the actuator through the solenoid valve 89. When in the flow increase working condition, the solenoid valve 12, the solenoid valve 45 and the solenoid valve 78 are powered on and opened, and the other solenoid valves are closed. In this way, the low-pressure oil enters the B1 chamber through the servo valve 14 and the solenoid valve 2 to push the piston rod 103 to move to the right. The oil in the A2 chamber is squeezed and enters the B position of the actuator through the solenoid valve 78, and the oil in the B2 chamber returns to the oil tank through the solenoid valve 45. Through the cooperation between the booster cylinder 1 and multiple solenoid valves, the switching between the ultra-high pressure working condition and the flow increase working condition can be met.

[0043] The present invention also provides a control method for a hydraulic system, comprising the following steps: setting the initial positions of the 1st to nth booster cylinders 1 to 0, m / n, ..., (n-1)m / n, respectively. The n booster cylinders 1 move to the right at the same time, the nth booster cylinder 1 moves to the rightmost end first and returns, and the first booster cylinder 1 moves to the rightmost end last and returns; at each moment, the sum of the movement speeds of the n booster cylinders 1 is V1+V2+···+Vn are the same, so that the flow and pressure output by the hydraulic system that can continuously and stably output ultra-high pressure and large flow are stable at every moment.

[0044] In one motion cycle of the booster cylinder 1, the motion states of the booster cylinder 1 include: acceleration motion, deceleration motion, uniform motion and return stroke. At the same time, at least two of the motion states of the n booster cylinders 1 are different motion states. In one motion cycle of the booster cylinder 1, the motion state of the piston rod 103 changes between acceleration motion, deceleration motion, uniform motion and return stroke. Since the initial positions of the piston rods 103 of the n booster cylinders 1 are different, the motion states of the n booster cylinders 1 at the same time will be different, so as to ensure that the sum of the motion speeds of the n booster cylinders 1 at each time remains stable.

[0045] The following description will be made by taking four booster cylinders 1 as an example.

[0046] The four booster cylinders 1 are respectively denoted as cylinder No. 1, cylinder No. 2, cylinder No. 3, and cylinder No. 4. The initial position of the piston rod 103 of cylinder No. 1 is 0, the initial position of cylinder No. 2 is 1m / 4, the initial position of cylinder No. 3 is 2m / 4, the initial position of cylinder No. 4 is 3m / 4, and the total movement stroke of the piston rod 103 / piston 101 is m. The starting points of cylinders No. 2, No. 3, and No. 4 are not 0 points, and hydraulic oil needs to be introduced to move the left end of the piston rod 103 to the set initial position. Therefore, when the four booster cylinders 1 start to move at the same time from their respective initial positions, the movement speeds of cylinders No. 2, No. 3, and No. 4 are not zero.

[0047] like Figure 4 As shown, in one movement cycle of the boost cylinder 1, the movement speed of the piston rod 103 / piston 101 will change between acceleration, deceleration, uniform speed, and return. Taking cylinder No. 1 as an example, starting from 0 o'clock, the movement state of the piston rod 103 changes as follows: acceleration, deceleration, uniform speed, acceleration, deceleration, acceleration, deceleration, uniform speed, acceleration, deceleration, and return. The duration of each movement state is not necessarily the same. In order to ensure the stability of the sum of V1+V2+V3+V4 at each moment, the following control strategy (Table 1) is adopted for the movement state of the four boost cylinders 1. The PLC can send the control instructions to the motion controller, and the motion controller sends them to the corresponding servo valve 14 to control the movement speed of the piston rod 103.

[0048] Table 1

[0049]

[0050] Assume that the pressure output by the low-pressure oil source is P, and the average flow rate delivered by the low-pressure oil source to each hydraulic cylinder 1 is q. When the hydraulic system capable of continuously and stably outputting ultra-high pressure and large flow is in an ultra-high pressure and large flow condition, the solenoid valve 2 3, the solenoid valve 3 4, and the solenoid valve 8 9 are powered on and opened, the solenoid valve 1 2, the solenoid valve 4 5, the solenoid valve 5 6, the solenoid valve 6 7, and the solenoid valve 7 8 are powered off and closed, and the low-pressure oil enters the A1 chamber of the booster cylinder 1 through the solenoid valve 2 3, and the piston rod 103 of the booster cylinder 1 moves to the right, and the B1 chamber of the booster cylinder 1 is replenished with oil, and the A2 chamber returns oil through the solenoid valve 3 4. The B2 chamber pressurizes the low-pressure oil and then flows into the A station of the actuator through the solenoid valve 8 9. The A station continuously and stably outputs a pressure of P*a, and an output flow rate of qn / a. When the hydraulic system that can continuously and stably output ultra-high pressure and large flow is in the flow increasing condition, solenoid valve 1 2, solenoid valve 4 5, and solenoid valve 7 8 are energized to open, solenoid valve 2 3, solenoid valve 3 4, solenoid valve 5 6, solenoid valve 6 7, and solenoid valve 8 9 are de-energized to close, and the low-pressure oil enters the B1 chamber of the booster cylinder 1 through solenoid valve 1 2, the piston rod 103 of the booster cylinder 1 moves to the right, the A1 chamber of the booster cylinder 1 is replenished with oil, and the B2 chamber returns oil through the solenoid valve 4 5. The A2 chamber pressurizes the low-pressure oil and then flows into the B station of the actuator through the solenoid valve 7 8. The B station continuously and stably outputs a pressure of P / a, and an output flow rate of q*n*a.

[0051] The present invention can achieve continuous output of ultra-high pressure by adopting a low-pressure oil source, and can achieve continuous output of large flow by adopting a small flow.

[0052] In summary, the hydraulic system and control method thereof capable of continuously and stably outputting ultra-high pressure and large flow of the present invention can realize the continuous and stable output of ultra-high pressure and large flow of the hydraulic system by improving the system structure, through the coordinated work of n hydraulic modules, and the regulation of the movement speed and starting position of n booster cylinders 1. When one of the booster cylinders 1 returns from the end point to the starting point, the system output is kept stable by regulating the speed of the remaining n-1 booster cylinders 1. The speed regulation is shared by the remaining n-1 booster cylinders 1 and will not be concentrated on only one booster cylinder 1. The booster cylinder 1 is less impacted, which is beneficial to extending the service life of the booster cylinder 1. The coordinated cooperation of the n booster cylinders 1 enables the hydraulic system to output ultra-high pressure and large flow. The size of each booster cylinder 1 does not need to be made very large, which is beneficial to reducing manufacturing costs.

[0053] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A hydraulic system capable of continuously and stably outputting ultra-high pressure and large flow, characterized in that: include: n hydraulic modules, each of which comprises a boosting cylinder (1), the stroke of the boosting cylinder (1) is m, the initial positions of the n boosting cylinders (1) are respectively 0, m / n, ..., (n-1)m / n; the movement speeds of the n boosting cylinders (1) are respectively V1, V2, ..., V n The effective area of ​​the booster cylinder (1) is X, and the flow rate output by the hydraulic system is Q=X(V1+V2+···+V n ), where V1+V2+···+V n The sum of is the same, n≥2; In one movement cycle of the boosting cylinder (1), the movement states of the boosting cylinder (1) include: accelerated movement, decelerated movement, uniform speed movement and return movement; at the same time, at least two of the movement states of the n boosting cylinders (1) are different movement states; The booster oil cylinder (1) comprises: a cylinder barrel (102), a piston (101) and a piston rod (103); the piston (101) and the piston rod (103) are fixedly connected; an A1 chamber is formed between the left end of the piston (101) and the cylinder barrel (102); an A2 chamber is formed between the right end of the piston (101) and the cylinder barrel (102); a B1 chamber is formed between the left end of the piston rod (103) and the cylinder barrel (102); and a B2 chamber is formed between the right end of the piston rod (103) and the cylinder barrel (102); wherein the ratio of the effective area of ​​the A1 chamber to the effective area of ​​the B2 chamber is a, and the ratio of the effective area of ​​the B1 chamber to the effective area of ​​the A2 chamber is 1 / a; The hydraulic module comprises: a solenoid valve 1 (2), a solenoid valve 2 (3), a solenoid valve 3 (4), a solenoid valve 4 (5), a solenoid valve 5 (6), a solenoid valve 6 (7), a solenoid valve 7 (8) and a solenoid valve 8 (9), wherein the solenoid valve 1 (2) and the solenoid valve 5 (6) are both connected to the B1 chamber, the solenoid valve 2 (3) and the solenoid valve 6 (7) are both connected to the A1 chamber, the solenoid valve 3 (4) and the solenoid valve 7 (8) are both connected to the A2 chamber, and the solenoid valve 4 (5) and the solenoid valve 8 (9) are both connected to the B2 chamber; The cylinder (102) comprises: a main body (1021), a first cover shell (1022) and a second cover shell (1023); the first cover shell (1022) and the second cover shell (1023) are detachably connected to the left and right ends of the main body (1021), respectively; a B1 cavity is formed between the first cover shell (1022) and the piston rod (103), and a B2 cavity is formed between the second cover shell (1023) and the piston rod (103).

2. The hydraulic system capable of continuously and stably outputting ultra-high pressure and large flow as claimed in claim 1, characterized in that: The hydraulic module further comprises: a displacement sensor and a servo control module, wherein the displacement sensor is used to monitor the position of the piston (101) of the boosting cylinder (1), and the servo control module is used to control the movement speed of the boosting cylinder (1).

3. A control method for a hydraulic system capable of continuously and stably outputting ultra-high pressure and large flow as claimed in any one of claims 1 to 2, characterized in that: The following steps are involved: The initial positions of the first to nth booster cylinders (1) are set to 0, m / n, ..., (n-1)m / n, respectively; The n booster cylinders (1) move to the right at the same time, the nth booster cylinder (1) moves to the rightmost end first and returns, and the first booster cylinder (1) moves to the rightmost end last and returns; at each moment, the sum of the movement speeds of the n booster cylinders (1) is V1+V2+···+V n are the same, so that the flow and pressure output by the hydraulic system that can continuously and stably output ultra-high pressure and large flow are stable at every moment.

4. The control method of a hydraulic system capable of continuously and stably outputting ultra-high pressure and large flow as claimed in claim 3, characterized in that: Assume that the pressure output by the low-pressure oil source is P, and the average flow rate of the low-pressure oil source delivered to each hydraulic cylinder (1) is q; when the hydraulic system capable of continuously and stably outputting ultra-high pressure and large flow rate is in an ultra-high pressure and large flow rate working condition, the solenoid valve 2 (3), the solenoid valve 3 (4), and the solenoid valve 8 (9) are energized to open, the solenoid valve 1 (2), the solenoid valve 4 (5), the solenoid valve 5 (6), the solenoid valve 6 (7), and the solenoid valve 7 (8) are de-energized to close, and the low-pressure oil enters the A1 chamber of the boosting cylinder (1) through the solenoid valve 2 (3), the piston rod (103) of the boosting cylinder (1) moves to the right, the B1 chamber of the boosting cylinder (1) is replenished with oil, the A2 chamber returns oil through the solenoid valve 3 (4), the B2 chamber pressurizes the low-pressure oil and then flows into the A station of the actuator through the solenoid valve 8 (9), and the A station continuously and stably outputs a pressure of P*a, and an output flow rate of qn / a.

5. The control method of a hydraulic system capable of continuously and stably outputting ultra-high pressure and large flow as claimed in claim 3, characterized in that: Assume that the pressure output by the low-pressure oil source is P, and the average flow rate of the low-pressure oil source delivered to each hydraulic cylinder (1) is q; when the hydraulic system capable of continuously and stably outputting ultra-high pressure and large flow rate is in a flow rate increasing condition, the solenoid valve 1 (2), the solenoid valve 4 (5), and the solenoid valve 7 (8) are energized and opened, the solenoid valve 2 (3), the solenoid valve 3 (4), the solenoid valve 5 (6), the solenoid valve 6 (7), and the solenoid valve 8 (9) are de-energized and closed, and the low-pressure oil enters the B1 chamber of the boosting cylinder (1) through the solenoid valve 1 (2), the piston rod (103) of the boosting cylinder (1) moves to the right, the A1 chamber of the boosting cylinder (1) is replenished with oil, and the B2 chamber returns oil through the solenoid valve 4 (5), and the A2 chamber pressurizes the low-pressure oil and then flows into the B station of the actuator through the solenoid valve 7 (8), and the B station continuously and stably outputs a pressure of P / a, and an output flow rate of q*n*a.

6. The control method of a hydraulic system capable of continuously and stably outputting ultra-high pressure and large flow as claimed in claim 3, characterized in that: In one movement cycle of the booster cylinder (1), the movement state of the piston rod (103) changes between acceleration movement, deceleration movement, uniform speed movement and return movement. Since the initial positions of the piston rods (103) of the n booster cylinders (1) are all different, the movement states of the n booster cylinders (1) at the same time will be different, so as to ensure that the sum of the movement speeds of the n booster cylinders (1) at each time remains stable.

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