A CNC hydraulic pad control system

Abstract

The present invention discloses a numerically controlled hydraulic cushion control system, comprising: a pump source unit, comprising a servo pump, a first two-way cartridge valve, a second two-way cartridge valve, a third two-way cartridge valve, a fourth two-way cartridge valve, and a fifth two-way cartridge valve; the first, second, and fifth two-way cartridge valves are directional valves, and the third and fourth two-way cartridge valves are pressure valves; a control unit, comprising a sixth, seventh, eighth, and ninth two-way cartridge valves, an electromagnetic reversing valve, a throttle valve, and a safety valve; the sixth and seventh two-way cartridge valves are directional valves, and the eighth two-way cartridge valve is a directional valve capable of monitoring valve core position. The numerically controlled hydraulic cushion control system of the present invention achieves high precision in cylinder positioning.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic transmission, in particular to a numerically controlled hydraulic pad control system. Background Art

[0002] CNC hydraulic pads are the core function of mechanical press equipment. They have the advantages of tensile pressure setting, fast dynamic response to various complex processes, and high pressure regulation accuracy, which greatly improves production efficiency and has great development in stability and remote intelligent monitoring functions.

[0003] However, the existing numerical control hydraulic pad control system has low accuracy in positioning the oil cylinder. Summary of the Invention

[0004] The purpose of the present invention is to provide a numerically controlled hydraulic pad control system to solve the problems existing in the above-mentioned prior art and improve the accuracy of cylinder positioning.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a numerical control hydraulic pad control system, including a servo pump and a controller.

[0007] The oil inlet of the servo pump is connected to the oil tank, and the oil outlet of the servo pump is connected to the A cavity of the first two-way cartridge valve and the A cavity of the third two-way cartridge valve respectively;

[0008] The C cavity of the third two-way cartridge valve is connected to the oil inlet of the first relief valve and the B port of the first two-position four-way solenoid valve respectively; the T port of the first two-position four-way solenoid valve and the oil outlet of the first relief valve are both connected to the oil tank and the B cavity of the third two-way cartridge valve;

[0009] The B cavity of the first two-way cartridge valve is respectively connected to the A cavity of the fifth two-way cartridge valve, the P port of the fourth two-position four-way valve, the inlet of the throttle valve, the P port of the seventh two-position four-way solenoid valve, the A cavity of the sixth two-way cartridge valve, the P port of the sixth two-position four-way solenoid valve, the C cavity of the first two-way cartridge valve, the A cavity of the second two-way cartridge valve and the P port of the second two-position four-way solenoid valve;

[0010] The A port of the second two-position four-way solenoid valve is connected to the C cavity of the second two-way cartridge valve; the T port of the second two-position four-way solenoid valve is connected to the oil tank; the B cavity of the second two-way cartridge valve is connected to the oil tank;

[0011] Port A of the sixth two-position four-way solenoid valve is in communication with cavity C of the sixth two-way cartridge valve, and cavity B of the sixth two-way cartridge valve is in communication with cavity A of the seventh two-way cartridge valve; and cavity B and cavity C of the seventh two-way cartridge valve are respectively in communication with cavity A of the eighth two-way cartridge valve;

[0012] The B chamber of the eighth two-way cartridge valve is respectively connected to the plug chamber of the oil cylinder, the safety valve, and the P port of the seventh two-position four-way solenoid valve, and the safety valve is connected to the oil tank; the C chamber of the eighth two-way cartridge valve is connected to the A port and the B port of the seventh two-position four-way solenoid valve, and the T port of the seventh two-position four-way solenoid valve is connected to the oil tank; the valve core of the eighth two-way cartridge valve is provided with a first displacement sensor;

[0013] The outlet of the throttle valve is connected to the P port of the fifth two-position four-way solenoid valve, the T port of the fifth two-position four-way solenoid valve is connected to the fuel tank, and the B port of the fifth two-position four-way solenoid valve is connected to the A cavity of the eighth two-way cartridge valve;

[0014] Chamber A of the eighth two-way cartridge valve is also in communication with chamber A of the ninth two-way cartridge valve and the inlet of the second relief valve; chamber B of the ninth two-way cartridge valve is in communication with the oil tank; the inlet of the second relief valve is also in communication with chamber C of the ninth two-way cartridge valve and the first end of the filter; the second end of the filter is in communication with one end of the proportional pressure valve; the outlet of the second relief valve and the other end of the proportional pressure valve are respectively in communication with the oil tank;

[0015] The B chamber and C chamber of the fifth two-way cartridge valve and the A chamber of the fourth two-way cartridge valve are respectively connected to the rod chamber of the oil cylinder; the A port of the fourth two-position four-way solenoid valve is connected to the C chamber of the fifth two-way cartridge valve, the B port of the fourth two-position four-way solenoid valve is blocked, and the T port is connected to the oil tank;

[0016] The B chamber of the fourth two-way cartridge valve is in communication with the oil tank, the C chamber of the fourth two-way cartridge valve is in communication with the inlet of the third relief valve and the P port of the third two-position four-way solenoid valve, respectively; the A port of the third two-position four-way solenoid valve is blocked, and the B port is in communication with the inlet of the fourth relief valve; the T port of the third two-position four-way solenoid valve, the outlet of the fourth relief valve, and the outlet of the third relief valve are in communication with the oil tank, respectively;

[0017] A second displacement sensor is provided on the hydraulic rod of the oil cylinder;

[0018] The servo motor in the servo pump, the first two-position four-way solenoid valve, the second two-position four-way solenoid valve, the third two-position four-way solenoid valve, the fourth two-position four-way solenoid valve, the fifth two-position four-way solenoid valve, the sixth two-position four-way solenoid valve, the seventh two-position four-way solenoid valve, the first displacement sensor and the second displacement sensor are respectively connected to the controller signal.

[0019] Preferably, a first one-way valve is provided on the connecting passage between the B chamber of the eighth two-way cartridge valve and the P port of the seventh two-position four-way solenoid valve, and the first one-way valve allows the oil to flow only from the B chamber of the eighth two-way cartridge valve to the P port of the seventh two-position four-way solenoid valve.

[0020] Preferably, a second one-way valve is provided on the communication passage between the B chamber of the first two-way cartridge valve and the P port of the seventh two-position four-way solenoid valve, and the second one-way valve allows the oil to flow only from the B chamber of the first two-way cartridge valve to the P port of the seventh two-position four-way solenoid valve.

[0021] Preferably, a third one-way valve is provided on the connecting passage between the A port of the fourth two-position four-way solenoid valve and the C cavity of the fifth two-way cartridge valve, and the third one-way valve allows the oil to flow only from the A port of the fourth two-position four-way solenoid valve to the C cavity of the fifth two-way cartridge valve.

[0022] Preferably, a fourth one-way valve is provided on the communication passage between the rod cavity and the C cavity of the fifth two-way cartridge valve, and the fourth one-way valve allows oil to flow only from the rod cavity to the C cavity of the fifth two-way cartridge valve.

[0023] Preferably, it is divided into a pump source unit and a control unit;

[0024] The pump source unit includes a servo pump, a first two-way cartridge valve, a second two-way cartridge valve, a third two-way cartridge valve, a fourth two-way cartridge valve, a fifth two-way cartridge valve, the first two-position four-way solenoid valve, the second two-position four-way solenoid valve, the third two-position four-way solenoid valve, the fourth two-position four-way solenoid valve, the first relief valve, the third relief valve and the fourth relief valve;

[0025] The control unit includes a sixth two-way cartridge valve, a seventh two-way cartridge valve, an eighth two-way cartridge valve, a ninth two-way cartridge valve, the fifth two-position four-way solenoid valve, the sixth two-position four-way solenoid valve, the seventh two-position four-way solenoid valve, the proportional pressure valve, the safety valve and the second overflow valve.

[0026] Preferably, a first pressure sensor and a first pressure measuring interface are provided on the connecting passage between the rod chamber and the B chamber of the fifth two-way cartridge valve; a second pressure sensor and a pressure gauge are provided on the connecting passage between the plug chamber and the B chamber of the eighth two-way cartridge valve; and a second pressure measuring interface is provided on the connecting passage between the servo pump and the A chamber of the third two-way cartridge valve.

[0027] Preferably, both the P port and the B port of the first two-position four-way solenoid valve are blocked.

[0028] Compared with the prior art, the present invention has achieved the following technical effects:

[0029] The numerically controlled hydraulic pad control system of the present invention utilizes a servo motor pump assembly as a pump source device, which is more economical and environmentally friendly. The use of a two-way cartridge valve that can monitor the position of the valve core can more clearly understand the system supply flow, thereby making it easier to control the operating speed. The proportional pressure pilot valve can be used to steplessly control the pressure of the system, thereby controlling the stress during stretching. The above device can achieve flow and pressure regulation, making the equipment more intelligent. The device has a simple and compact structure and a reasonable design. It can meet the functions of each part and has sufficient margin. The functional components and ancillary facilities are reasonably arranged. The design and the integration of the two-way cartridge valve make the system more compact and reasonable, providing convenience for the subsequent inspection and maintenance of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 This is a schematic diagram of the structure of the CNC hydraulic pad control system of the present invention;

[0032] Figure 2 It is a structural diagram of the pump source unit in the numerical control hydraulic pad control system of the present invention;

[0033] Figure 3 This is a schematic diagram of the structure of the control unit in the CNC hydraulic pad control system of the present invention;

[0034] Among them, 1. First two-way cartridge valve; 2. Second two-way cartridge valve; 3. Third two-way cartridge valve; 4. Fourth two-way cartridge valve; 5. Fifth two-way cartridge valve; 6. Sixth two-way cartridge valve; 7. Seventh two-way cartridge valve; 8. Eighth two-way cartridge valve; 9. Ninth two-way cartridge valve; 10. Fifth two-position four-way solenoid valve; 11. Throttle valve; 12. Safety valve; 13. First two-position four-way solenoid valve; 14. Second two-position four-way solenoid valve ; 15. Third two-position four-way solenoid valve; 16. Fourth two-position four-way solenoid valve; 17. Sixth two-position four-way solenoid valve; 18. Seventh two-position four-way solenoid valve; 19. Filter; 20. Oil tank; 21. Servo pump; 22. First overflow valve; 23. Second overflow valve; 24. Third overflow valve; 25. Fourth overflow valve; 26. Proportional pressure valve; 27. First pressure sensor; 28. Second pressure sensor; 29. ​​Oil cylinder. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0036] The purpose of the present invention is to provide a numerically controlled hydraulic pad control system to solve the problems existing in the above-mentioned prior art and improve the energy saving and safety of the numerically controlled hydraulic pad control system.

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] like Figure 1 As shown, this embodiment provides a numerically controlled hydraulic pad control system, including a servo pump 21 and a controller;

[0039] The oil inlet of the servo pump 21 is connected to the oil tank 20, and the oil outlet of the servo pump 21 is connected to the A cavity of the first two-way cartridge valve 1 and the A cavity of the third two-way cartridge valve 3 respectively;

[0040] The C cavity of the third two-way cartridge valve 3 is respectively connected to the oil inlet hole of the first relief valve 22 and the B port of the first two-position four-way solenoid valve 13; the T port of the first two-position four-way solenoid valve 13 and the oil outlet hole of the first relief valve 22 are both connected to the oil tank 20 and the B cavity of the third two-way cartridge valve 3; the P port and B port of the first two-position four-way solenoid valve 13 are both blocked.

[0041] The B cavity of the first two-way cartridge valve 1 is respectively connected to the A cavity of the fifth two-way cartridge valve 5, the P port of the fourth two-position four-way valve, the inlet of the throttle valve 11, the P port of the seventh two-position four-way solenoid valve 18, the A cavity of the sixth two-way cartridge valve 6, the P port of the sixth two-position four-way solenoid valve 17, the C cavity of the first two-way cartridge valve 1, the A cavity of the second two-way cartridge valve 2 and the P port of the second two-position four-way solenoid valve 14;

[0042] The A port of the second two-position four-way solenoid valve 14 is connected to the C cavity of the second two-way cartridge valve 2; the T port of the second two-position four-way solenoid valve 14 is connected to the oil tank 20; the B cavity of the second two-way cartridge valve 2 is connected to the oil tank 20;

[0043] Port A of the sixth two-position four-way solenoid valve 17 is connected to cavity C of the sixth two-way cartridge valve 6, and cavity B of the sixth two-way cartridge valve 6 is connected to cavity A of the seventh two-way cartridge valve 7; and cavity B and cavity C of the seventh two-way cartridge valve 7 are respectively connected to cavity A of the eighth two-way cartridge valve 8;

[0044] The B chamber of the eighth two-way cartridge valve 8 is respectively connected to the plug chamber of the oil cylinder 1, the safety valve 12, and the P port of the seventh two-position four-way solenoid valve 18, and the safety valve 12 is connected to the oil tank 20; the C chamber of the eighth two-way cartridge valve 8 is connected to the A port of the seventh two-position four-way solenoid valve 18, and the B port of the seventh two-position four-way solenoid valve 18 is connected to the control chamber of the eighth two-way cartridge valve 8. When the seventh two-position four-way solenoid valve 18 is energized, the P port and the B port of the seventh two-position four-way solenoid valve 18 are connected, and the oil enters the control chamber of the eighth two-way cartridge valve 8 through the B port of the seventh two-position four-way solenoid valve 18, which can make the opening of the valve core of the eighth two-way cartridge valve 8 more reliable; the T port of the seventh two-position four-way solenoid valve 18 is connected to the oil tank 20; a first displacement sensor is provided on the valve core of the eighth two-way cartridge valve 8;

[0045] The outlet of the throttle valve 11 is connected to the P port of the fifth two-position four-way solenoid valve 10, the T port of the fifth two-position four-way solenoid valve 10 is connected to the fuel tank 20, and the B port of the fifth two-position four-way solenoid valve 10 is connected to the A cavity of the eighth two-way cartridge valve 8;

[0046] Chamber A of the eighth two-way cartridge valve 8 is also connected to chamber A of the ninth two-way cartridge valve 9 and the inlet of the second relief valve 23. Chamber B of the ninth two-way cartridge valve 9 is connected to the fuel tank 20. The inlet of the second relief valve 23 is also connected to chamber C of the ninth two-way cartridge valve 9 and the first end of the filter 19. The second end of the filter 19 is connected to one end of the proportional pressure valve 26. The outlet of the second relief valve 23 and the other end of the proportional pressure valve 26 are respectively connected to the fuel tank 20.

[0047] The B and C chambers of the fifth two-way cartridge valve 5 and the A chamber of the fourth two-way cartridge valve 4 are respectively connected to the rod chamber of the oil cylinder 1; the A port of the fourth two-position four-way solenoid valve 16 is connected to the C chamber of the fifth two-way cartridge valve 5, the B port of the fourth two-position four-way solenoid valve 16 is blocked, and the T port is connected to the oil tank 20;

[0048] The B chamber of the fourth two-way cartridge valve 4 is in communication with the fuel tank 20 , and the C chamber of the fourth two-way cartridge valve 4 is in communication with the inlet of the third relief valve 24 and the P port of the third two-position four-way solenoid valve 15 , respectively. The A port of the third two-position four-way solenoid valve 15 is blocked, and the B port is in communication with the inlet of the fourth relief valve 25 . The T port of the third two-position four-way solenoid valve 15 , the outlet of the fourth relief valve 25 , and the outlet of the third relief valve 24 are in communication with the fuel tank 20 , respectively.

[0049] A second displacement sensor is provided on the hydraulic rod of the oil cylinder 1;

[0050] The servo motor, the first two-position four-way solenoid valve 13, the second two-position four-way solenoid valve 14, the third two-position four-way solenoid valve 15, the fourth two-position four-way solenoid valve 16, the fifth two-position four-way solenoid valve 10, the sixth two-position four-way solenoid valve 17, the seventh two-position four-way solenoid valve 18, the first displacement sensor and the second displacement sensor in the servo pump 21 are respectively connected to the controller signal.

[0051] A first one-way valve is provided on the communication passage between the B chamber of the eighth two-way cartridge valve 8 and the P port of the seventh two-position four-way solenoid valve 18. The first one-way valve allows oil to flow only from the B chamber of the eighth two-way cartridge valve 8 to the P port of the seventh two-position four-way solenoid valve 18.

[0052] A second one-way valve is provided on the communication passage between the B chamber of the first two-way cartridge valve 1 and the P port of the seventh two-position four-way solenoid valve 18. The second one-way valve allows oil to flow only from the B chamber of the first two-way cartridge valve 1 to the P port of the seventh two-position four-way solenoid valve 18.

[0053] A third one-way valve is provided on the communication passage between port A of the fourth two-position four-way solenoid valve 16 and cavity C of the fifth two-way cartridge valve 5. The third one-way valve allows oil to flow only from port A of the fourth two-position four-way solenoid valve 16 to cavity C of the fifth two-way cartridge valve 5.

[0054] A fourth one-way valve is provided on the communication passage between the rod chamber and the C chamber of the fifth two-way cartridge valve 5 . The fourth one-way valve allows oil to flow only from the rod chamber to the C chamber of the fifth two-way cartridge valve 5 .

[0055] It is divided into a pump source unit and a control unit; the pump source unit includes a servo pump 21, a first two-way cartridge valve 1, a second two-way cartridge valve 2, a third two-way cartridge valve 3, a fourth two-way cartridge valve 4, a fifth two-way cartridge valve 5, a first two-position four-way solenoid valve 13, a second two-position four-way solenoid valve 14, a third two-position four-way solenoid valve 15, a fourth two-position four-way solenoid valve 16, a first overflow valve 22, a third overflow valve 24 and a fourth overflow valve 25; the control unit includes a sixth two-way cartridge valve 6, a seventh two-way cartridge valve 7, an eighth two-way cartridge valve 8, a ninth two-way cartridge valve 9, a fifth two-position four-way solenoid valve 10, a sixth two-position four-way solenoid valve 17, a seventh two-position four-way solenoid valve 18, a proportional pressure valve 26, a safety valve 12 and a second overflow valve 23.

[0056] A first pressure sensor 27 and a first pressure measuring interface are provided on the connecting passage between the rod chamber and the B chamber of the fifth two-way cartridge valve 5; a second pressure sensor 28 and a pressure gauge are provided on the connecting passage between the plug chamber and the B chamber of the eighth two-way cartridge valve 8; a second pressure measuring interface is provided on the connecting passage between the servo pump 21 and the A chamber of the third two-way cartridge valve 3.

[0057] The specific working principle of the CNC hydraulic pad control system of this embodiment is as follows:

[0058] When the system is heated up: the first two-position four-way solenoid valve 13 and the second two-position four-way solenoid valve 14 are energized at the same time, and after the servo pump 21 pumps out the oil in the oil tank 20, the oil passes through the first two-way cartridge valve 1 and the second two-way cartridge valve 2, and then flows back to the oil tank 20. The system's pump-up and pressure circulation increases the temperature of the oil, thereby preparing for the normal operation of the system.

[0059] When system cylinder 1 moves upward: the first two-position four-way solenoid valve 13, the third two-position four-way solenoid valve 15, the sixth two-position four-way solenoid valve 17, and the seventh two-position four-way solenoid valve 18 are energized simultaneously, proportional pressure valve 26 is energized, servo pump 21 operates, and oil passes through the first two-way cartridge valve 1, the sixth two-way cartridge valve 6, the seventh two-way cartridge valve 7, and the eighth two-way cartridge valve 8 in sequence into the plug chamber of cylinder 1, thereby pushing cylinder 1 upward without load. At the same time, the oil in the rod chamber of cylinder 1 returns to the fuel tank 20 through the fourth two-way cartridge valve 4, completing the upward movement of cylinder 1.

[0060] When the system's oil cylinder 1 is positioned, the first two-position four-way solenoid valve 13, the fifth two-position four-way solenoid valve 10, and the seventh two-position four-way solenoid valve 18 are simultaneously energized, the proportional pressure valve 26 is energized, and the servo pump 21 operates. Oil then passes through the first two-way cartridge valve 1, the throttle valve 11, the fifth two-position four-way solenoid valve 10, and the eighth two-way cartridge valve 8 in sequence and enters the plug chamber of the oil cylinder 1. Since the flow rate can be adjusted by the throttle valve 11 and the valve core position can be detected by the first displacement sensor installed on the eighth two-way cartridge valve 8, the valve core of the eighth two-way cartridge valve 8 can be opened to the desired position, thereby achieving precise control of the flow rate. In conjunction with the second pressure sensor 28 and the second displacement sensor on the hydraulic rod of the oil cylinder 1, the oil cylinder 1 can be precisely positioned.

[0061] When system cylinder 1 is extending, the fifth two-position four-way solenoid valve 10 is energized, and proportional pressure valve 26 is energized. Cylinder 1 contacts the workpiece and is passively pressurized. Oil then returns through the eighth two-way cartridge valve 8 and the ninth two-way cartridge valve 9. Proportional pressure valve 26 adjusts the system's passive pressure, thereby controlling the speed and completing the stretching action.

[0062] When the system cylinder 1 moves downward: the first two-position four-way solenoid valve 13, the fourth two-position four-way solenoid valve 16, and the seventh two-position four-way solenoid valve 18 are energized at the same time, and the oil passes through the first two-way cartridge valve 1 and the fifth two-way cartridge valve 5 in sequence and enters the rod chamber of the cylinder 1. The oil in the plug chamber of the cylinder 1 returns through the eighth two-way cartridge valve 8 and the ninth two-way cartridge valve 9, completing the downward action of the cylinder 1 and the system returns.

[0063] The first two-way cartridge valve 1, the second two-way cartridge valve 2 and the fifth two-way cartridge valve 5 are directional valves, the third two-way cartridge valve 3 and the fourth two-way cartridge valve 4 are pressure valves; the sixth two-way cartridge valve 6 and the seventh two-way cartridge valve 7 are directional valves, and the eighth two-way cartridge valve 8 is a directional valve capable of monitoring the valve core position.

[0064] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A CNC hydraulic pad control system, characterized by: Including servo pump and controller, The oil inlet of the servo pump is connected to the oil tank, and the oil outlet of the servo pump is connected to the A cavity of the first two-way cartridge valve and the A cavity of the third two-way cartridge valve respectively; The C cavity of the third two-way cartridge valve is connected to the oil inlet of the first relief valve and the B port of the first two-position four-way solenoid valve respectively; the T port of the first two-position four-way solenoid valve and the oil outlet of the first relief valve are both connected to the oil tank and the B cavity of the third two-way cartridge valve; The B cavity of the first two-way cartridge valve is respectively connected to the A cavity of the fifth two-way cartridge valve, the P port of the fourth two-position four-way solenoid valve, the inlet of the throttle valve, the P port of the seventh two-position four-way solenoid valve, the A cavity of the sixth two-way cartridge valve, the P port of the sixth two-position four-way solenoid valve, the C cavity of the first two-way cartridge valve, the A cavity of the second two-way cartridge valve, and the P port of the second two-position four-way solenoid valve; The A port of the second two-position four-way solenoid valve is connected to the C cavity of the second two-way cartridge valve; the T port of the second two-position four-way solenoid valve is connected to the oil tank; the B cavity of the second two-way cartridge valve is connected to the oil tank; Port A of the sixth two-position four-way solenoid valve is in communication with cavity C of the sixth two-way cartridge valve, and cavity B of the sixth two-way cartridge valve is in communication with cavity A of the seventh two-way cartridge valve; and cavity B and cavity C of the seventh two-way cartridge valve are respectively in communication with cavity A of the eighth two-way cartridge valve; The B chamber of the eighth two-way cartridge valve is respectively connected to the plug chamber of the oil cylinder, the safety valve, and the P port of the seventh two-position four-way solenoid valve, and the safety valve is connected to the oil tank; the C chamber of the eighth two-way cartridge valve is connected to the A port and the B port of the seventh two-position four-way solenoid valve, and the T port of the seventh two-position four-way solenoid valve is connected to the oil tank; the valve core of the eighth two-way cartridge valve is provided with a first displacement sensor; The outlet of the throttle valve is connected to the P port of the fifth two-position four-way solenoid valve, the T port of the fifth two-position four-way solenoid valve is connected to the fuel tank, and the B port of the fifth two-position four-way solenoid valve is connected to the A cavity of the eighth two-way cartridge valve; Chamber A of the eighth two-way cartridge valve is also in communication with chamber A of the ninth two-way cartridge valve and the inlet of the second relief valve; chamber B of the ninth two-way cartridge valve is in communication with the oil tank; the inlet of the second relief valve is also in communication with chamber C of the ninth two-way cartridge valve and the first end of the filter; the second end of the filter is in communication with one end of the proportional pressure valve; the outlet of the second relief valve and the other end of the proportional pressure valve are respectively in communication with the oil tank; The B chamber and C chamber of the fifth two-way cartridge valve and the A chamber of the fourth two-way cartridge valve are respectively connected to the rod chamber of the oil cylinder; the A port of the fourth two-position four-way solenoid valve is connected to the C chamber of the fifth two-way cartridge valve, the B port of the fourth two-position four-way solenoid valve is blocked, and the T port is connected to the oil tank; The B chamber of the fourth two-way cartridge valve is in communication with the oil tank, the C chamber of the fourth two-way cartridge valve is in communication with the inlet of the third relief valve and the P port of the third two-position four-way solenoid valve, respectively; the A port of the third two-position four-way solenoid valve is blocked, and the B port is in communication with the inlet of the fourth relief valve; the T port of the third two-position four-way solenoid valve, the outlet of the fourth relief valve, and the outlet of the third relief valve are in communication with the oil tank, respectively; A second displacement sensor is provided on the hydraulic rod of the oil cylinder; The servo motor in the servo pump, the first two-position four-way solenoid valve, the second two-position four-way solenoid valve, the third two-position four-way solenoid valve, the fourth two-position four-way solenoid valve, the fifth two-position four-way solenoid valve, the sixth two-position four-way solenoid valve, the seventh two-position four-way solenoid valve, the first displacement sensor and the second displacement sensor are respectively connected to the controller signal.

2. The CNC hydraulic pad control system according to claim 1, characterized in that: A first one-way valve is provided on the communication passage between the B chamber of the eighth two-way cartridge valve and the P port of the seventh two-position four-way solenoid valve. The first one-way valve allows oil to flow only from the B chamber of the eighth two-way cartridge valve to the P port of the seventh two-position four-way solenoid valve.

3. The CNC hydraulic pad control system according to claim 1, characterized in that: A second one-way valve is provided on the communication passage between the B chamber of the first two-way cartridge valve and the P port of the seventh two-position four-way solenoid valve. The second one-way valve allows oil to flow only from the B chamber of the first two-way cartridge valve to the P port of the seventh two-position four-way solenoid valve.

4. The CNC hydraulic pad control system according to claim 1, characterized in that: A third one-way valve is provided on the communication passage between port A of the fourth two-position four-way solenoid valve and cavity C of the fifth two-way cartridge valve. The third one-way valve allows oil to flow only from port A of the fourth two-position four-way solenoid valve to cavity C of the fifth two-way cartridge valve.

5. The CNC hydraulic pad control system according to claim 1, characterized in that: A fourth one-way valve is provided on the communication passage between the rod chamber and the C chamber of the fifth two-way cartridge valve. The fourth one-way valve allows oil to flow only from the rod chamber to the C chamber of the fifth two-way cartridge valve.

6. The CNC hydraulic pad control system according to claim 1, characterized in that: Divided into pump source unit and control unit; The pump source unit includes a servo pump, a first two-way cartridge valve, a second two-way cartridge valve, a third two-way cartridge valve, a fourth two-way cartridge valve, a fifth two-way cartridge valve, the first two-position four-way solenoid valve, the second two-position four-way solenoid valve, the third two-position four-way solenoid valve, the fourth two-position four-way solenoid valve, the first relief valve, the third relief valve and the fourth relief valve; The control unit includes a sixth two-way cartridge valve, a seventh two-way cartridge valve, an eighth two-way cartridge valve, a ninth two-way cartridge valve, the fifth two-position four-way solenoid valve, the sixth two-position four-way solenoid valve, the seventh two-position four-way solenoid valve, the proportional pressure valve, the safety valve and the second overflow valve.

7. The CNC hydraulic pad control system according to claim 1, characterized in that: A first pressure sensor and a first pressure measuring interface are provided on the connecting passage between the rod chamber and the B chamber of the fifth two-way cartridge valve; a second pressure sensor and a pressure gauge are provided on the connecting passage between the plug chamber and the B chamber of the eighth two-way cartridge valve; a second pressure measuring interface is provided on the connecting passage between the servo pump and the A chamber of the third two-way cartridge valve.

8. The CNC hydraulic pad control system according to claim 1, characterized in that: The P port and the A port of the first two-position four-way solenoid valve are both blocked.

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