Pressure maintaining and oil supplementing system of servo valve

Abstract

The utility model discloses a pressure maintaining and oil supplementing system of a servo valve, which comprises the servo valve and a first cartridge valve, a port A of the first cartridge valve is connected with a rod cavity of an oil cylinder, and a port B of the first cartridge valve is connected with a port A of the servo valve; a port A of the second cartridge valve is connected with a rodless cavity of the oil cylinder, and a port B of the second cartridge valve is connected with a port B of the servo valve; an outlet of the first oil supplementing one-way valve is connected with a port A of the first cartridge valve, and an inlet of the first oil supplementing one-way valve is connected with the low-pressure oil port; and an outlet of the second oil supplementing one-way valve is connected with a port A of the second cartridge valve, and an inlet of the second oil supplementing one-way valve is connected with the low-pressure oil port. Cartridge valves are arranged at a port A and a port B of the servo valve, so that oil in the oil cylinder cannot flow and is in a static pressure maintaining state. When the low-pressure cavity of the oil cylinder needs to be refilled with oil, oil refilling can be achieved through the first oil refilling one-way valve or the second oil refilling one-way valve.

Description

Technical Field

[0001] The utility model relates to the technical field of servo valves, in particular to a pressure maintaining and oil replenishing system of a servo valve. Background Art

[0002] A servo valve is a device that controls hydraulic flow and pressure via electrical signals. When the spool is in the neutral position, the positional relationship between the spool and the valve body or sleeve can be described as "positive overlap," "negative overlap," or "zero overlap." Positive overlap means the width of the spool shoulder is wider than the window in the valve body or sleeve, requiring the spool to move a certain distance before the oil flow is connected. Negative overlap, on the other hand, creates the opposite situation, with significant leakage in the neutral position. The amount of overlap is related to the valve's response speed. A valve with positive overlap exhibits minimal leakage in the neutral position, but also exhibits slower response. Valves with negative or zero overlap have the fastest response and are generally used in high-frequency servo valves.

[0003] For high-frequency response conditions, valves with negative or zero overlap are most suitable. However, achieving these with dimensional precision is clearly too difficult. Therefore, to achieve zero output at zero position, a pressure-maintaining circuit is required. This allows for high-demand operating conditions, such as when the valve core is in the neutral position, with no flow input or output from the actuator, to maintain pressure, while maintaining high-frequency response during the actuator's operation. Utility Model Content

[0004] In order to solve the problems existing in the prior art, the utility model provides a pressure-maintaining and oil-supplying system for a servo valve, which can be applicable to working conditions with high-frequency response.

[0005] The technical solution adopted by the utility model to solve its technical problems is: a pressure-maintaining and oil-replenishing system of a servo valve, comprising: a servo valve, and a first cartridge valve, the A port of the first cartridge valve is connected to the rod chamber of the oil cylinder, and the B port of the first cartridge valve is connected to the A port of the servo valve; a second cartridge valve, the A port of the second cartridge valve is connected to the rodless chamber of the oil cylinder, and the B port of the second cartridge valve is connected to the B port of the servo valve; a first oil-replenishing one-way valve, the outlet of the first oil-replenishing one-way valve is connected to the A port of the first cartridge valve, and the inlet of the first oil-replenishing one-way valve is connected to the low-pressure oil port; a second oil-replenishing one-way valve, the outlet of the second oil-replenishing one-way valve is connected to the A port of the second cartridge valve, and the inlet of the second oil-replenishing one-way valve is connected to the low-pressure oil port.

[0006] Furthermore, it also includes: a first safety valve and a second safety valve, the first end of the first safety valve is connected to the rod chamber of the oil cylinder, the second end of the first safety valve is connected to the low-pressure oil port, the first end of the second safety valve is connected to the rodless chamber of the oil cylinder, and the second end of the second safety valve is connected to the low-pressure oil port.

[0007] Furthermore, it also includes: a solenoid valve, the solenoid valve is connected to the high-pressure oil port, and the pilot ports of the first cartridge valve and the second cartridge valve are both connected to the solenoid valve.

[0008] Furthermore, it also includes: a third cartridge valve, wherein the A port of the third cartridge valve is connected to the P port of the servo valve, the B port of the third cartridge valve is connected to the high-pressure oil port, and the pilot port of the third cartridge valve is connected to the solenoid valve.

[0009] Furthermore, it also includes: a filtering device, the filtering device is connected to the servo valve, and the filtering device is connected to the high-pressure oil port.

[0010] Furthermore, it also includes: a pilot-operated pressure reducing valve, the pilot-operated pressure reducing valve is connected to the filtering device, and the pilot-operated pressure reducing valve is connected to the high-pressure oil port.

[0011] Furthermore, it also includes: an energy storage module, which is used to provide hydraulic oil to the servo valve.

[0012] Furthermore, the energy storage module includes: an accumulator, a third safety valve, a first ball valve and a second ball valve, the third safety valve, the first ball valve and the second ball valve are all connected to the accumulator, the first ball valve is connected to the high-pressure oil port, and the second ball valve and the third safety valve are both connected to the pilot oil drain port.

[0013] The beneficial effect of the present invention is that, through structural improvements, cartridge valves are provided at ports A and B of the servo valve. The opening and closing of the first and second cartridge valves are controlled by external pilot oil, thereby ensuring that the oil in the cylinder cannot flow and remains in a static pressure-maintaining state. When the low-pressure chamber of the cylinder needs to be replenished with oil, this can be achieved through the first or second oil replenishment check valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] Figure 1 It is a structural diagram of the pressure-maintaining and oil-replenishing system of the present utility model.

[0016] In the figure: 1. Servo valve; 2. First cartridge valve; 3. Second cartridge valve; 4. First oil supply check valve; 5. Second oil supply check valve; 6. First safety valve; 7. Second safety valve; 8. Solenoid valve; 9. Third cartridge valve; 10. Filter device; 11. Pilot-operated pressure reducing valve; 12. Accumulator; 13. Third safety valve; 14. First ball valve; 15. Second ball valve. DETAILED DESCRIPTION

[0017] The present invention will now be described in further detail with reference to the accompanying drawings, which are simplified schematic diagrams that illustrate the basic structure of the present invention in a schematic manner.

[0018] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0019] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0020] like Figure 1 As shown, the pressure maintaining and oil replenishing system of the servo valve of the utility model includes: a servo valve 1, a first cartridge valve 2, a second cartridge valve 3, a first oil replenishing check valve 4 and a second oil replenishing check valve 5. The A port of the first cartridge valve 2 is connected to the rod cavity of the oil cylinder, and the B port of the first cartridge valve 2 is connected to the A port of the servo valve 1; the A port of the second cartridge valve 3 is connected to the rodless cavity of the oil cylinder, and the B port of the second cartridge valve 3 is connected to the B port of the servo valve 1; the outlet of the first oil replenishing check valve 4 is connected to the A port of the first cartridge valve 2, and the inlet of the first oil replenishing check valve 4 is connected to the low-pressure oil port; the outlet of the second oil replenishing check valve 5 is connected to the A port of the second cartridge valve 3, and the inlet of the second oil replenishing check valve 5 is connected to the low-pressure oil port.

[0021] It should be noted that the oil cylinder achieves telescopic motion through the input and output of hydraulic oil. While achieving this telescopic motion, it must also be capable of adapting to operating conditions such as high-frequency switching, speed control, and position control. In this embodiment, cartridge valves are installed at ports A and B of servo valve 1. The opening and closing of first cartridge valve 2 and second cartridge valve 3 require external pilot oil to control. This ensures that the oil in the oil cylinder cannot flow and remains in a static, pressure-maintaining state. When the low-pressure chamber of the oil cylinder requires oil replenishment, this can be achieved through first oil replenishment check valve 4 or second oil replenishment check valve 5.

[0022] Specifically, this embodiment further includes: a first safety valve 6, a second safety valve 7, a solenoid valve 8, and a third cartridge valve 9. The first end of the first safety valve 6 is connected to the rod chamber of the oil cylinder, and the second end of the first safety valve 6 is connected to the low-pressure oil port. The first end of the second safety valve 7 is connected to the rodless chamber of the oil cylinder, and the second end of the second safety valve 7 is connected to the low-pressure oil port. The solenoid valve 8 is connected to the high-pressure oil port. The pilot ports of the first cartridge valve 2 and the second cartridge valve 3 are both connected to the solenoid valve 8. Port A of the third cartridge valve 9 is connected to port P of the servo valve 1, port B of the third cartridge valve 9 is connected to the high-pressure oil port, and the pilot port of the third cartridge valve 9 is connected to the solenoid valve 8.

[0023] In other words, the solenoid valve 8 can control the on-off flow of the pilot hydraulic oil. When the solenoid valve 8 is energized, the hydraulic oil passes through the solenoid valve 8 and enters the upper chambers of the first cartridge valve 2 and the second cartridge valve 3, causing the valve core to move downward. At this time, the first cartridge valve 2 and the second cartridge valve 3 are in a closed state. The oil cylinder is isolated from the servo valve 1, and the rod chamber and the rodless chamber of the oil cylinder are in a pressure-maintaining static state. Since the load size will vary, the first safety valve 6 and the second safety valve 7 are set to ensure system safety. When the pressure in the oil cylinder cavity exceeds the set pressure of the safety valve, the safety valve spool opens and the excess oil is discharged back into the oil tank. In this process, since the volume of the high-pressure overflow side of the oil cylinder becomes smaller and the volume of the low-pressure side becomes larger, it is necessary to add oil to the low-pressure chamber. The A port of the third cartridge valve 9 is connected to the P port of the servo valve 1. The opening and closing of the third cartridge valve 9 can also be controlled by the solenoid valve 8. When the third cartridge valve 9 is closed, the hydraulic oil output from the high-pressure oil port can be completely isolated from the servo valve 1 and is not affected by the leakage of the servo valve 1, which is beneficial to improving the utilization rate of hydraulic energy and reducing the heat generation of the system.

[0024] For example, the first cartridge valve 2 , the second cartridge valve 3 , and the third cartridge valve 9 are all zero-leakage two-way cartridge valves, and the valve core seals are made of rubber material, with an ideal sealing effect.

[0025] This embodiment also includes a filter device 10 and a pilot-operated pressure-reducing valve 11. The filter device 10 is connected to the servo valve 1, which is then connected to the high-pressure oil port. The pilot-operated pressure-reducing valve 11 is also connected to the filter device 10, which is then connected to the high-pressure oil port. Due to the high-precision nature of the servo valve 1, the cleanliness of the oil must be extremely high. The filter device 10 effectively filters impurities from the oil, improving the reliability and stability of the servo valve 1. Furthermore, the pilot-operated pressure-reducing valve 11 is installed in the pilot oil supply path, enabling stepless adjustment of the pilot oil supply pressure.

[0026] This embodiment also includes an energy storage module, which is used to provide hydraulic oil to the servo valve 1. The energy storage module includes an accumulator 12, a third safety valve 13, a first ball valve 14, and a second ball valve 15. The third safety valve 13, the first ball valve 14, and the second ball valve 15 are all connected to the accumulator 12. The first ball valve 14 is connected to the high-pressure oil port, and the second ball valve 15 and the third safety valve 13 are both connected to the pilot oil drain port. When the output of the hydraulic pump cannot match the response requirements of the servo valve 1, the energy storage module can be opened to supply oil to the servo valve 1. For example, when the servo valve 1 is in a high-frequency switching state, the accumulator 12 can quickly supply high-pressure oil to the servo valve 1. The third safety valve 13 can ensure the safety of the energy storage module and prevent excessive pressure. The first ball valve 14 and the second ball valve 15 can control the on-off of the oil circuit.

[0027] In summary, the servo valve's pressure-maintaining oil-replenishing system of the present invention, through structural improvements, is suitable for operating the servo valve 1 under high-frequency response conditions. Cartridge valves are installed at ports A and B of the servo valve 1. The opening and closing of the first and second cartridge valves 2 and 3 are controlled by external pilot oil, ensuring that the oil in the cylinder cannot flow, maintaining a static pressure-maintaining state. When the low-pressure chamber of the cylinder requires oil replenishment, this is accomplished through the first or second oil replenishment check valve 4 and 5.

[0028] Based on the above-described preferred embodiments of the present invention, and in accordance with the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of the present invention. 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 servo valve pressure maintaining and oil replenishing system, characterized in that: include: servo valve (1), and a first cartridge valve (2), wherein port A of the first cartridge valve (2) is connected to the rod chamber of the oil cylinder, and port B of the first cartridge valve (2) is connected to port A of the servo valve (1); A second cartridge valve (3), wherein the port A of the second cartridge valve (3) is connected to the rodless chamber of the oil cylinder, and the port B of the second cartridge valve (3) is connected to the port B of the servo valve (1); a first oil replenishing one-way valve (4), wherein the outlet of the first oil replenishing one-way valve (4) is connected to the port A of the first cartridge valve (2), and the inlet of the first oil replenishing one-way valve (4) is connected to the low-pressure oil port; A second oil replenishing one-way valve (5), wherein the outlet of the second oil replenishing one-way valve (5) is connected to the A port of the second cartridge valve (3), and the inlet of the second oil replenishing one-way valve (5) is connected to the low-pressure oil port.

2. The servo valve pressure maintaining and oil replenishing system according to claim 1, characterized in that: Also includes: A first safety valve (6) and a second safety valve (7), wherein the first end of the first safety valve (6) is connected to the rod chamber of the oil cylinder, and the second end of the first safety valve (6) is connected to the low-pressure oil port; the first end of the second safety valve (7) is connected to the rodless chamber of the oil cylinder, and the second end of the second safety valve (7) is connected to the low-pressure oil port.

3. The servo valve pressure maintaining and oil replenishing system according to claim 1, characterized in that: Also includes: A solenoid valve (8) is connected to the high-pressure oil port, and the pilot ports of the first cartridge valve (2) and the second cartridge valve (3) are both connected to the solenoid valve (8).

4. The servo valve pressure maintaining and oil replenishing system according to claim 3, characterized in that: Also includes: A third cartridge valve (9), wherein the A port of the third cartridge valve (9) is connected to the P port of the servo valve (1), the B port of the third cartridge valve (9) is connected to the high-pressure oil port, and the pilot port of the third cartridge valve (9) is connected to the solenoid valve (8).

5. The servo valve pressure maintaining and oil replenishing system according to claim 1, characterized in that: Also includes: A filter device (10), wherein the filter device (10) is connected to the servo valve (1), and the filter device (10) is connected to a high-pressure oil port.

6. The servo valve pressure maintaining and oil replenishing system according to claim 5, characterized in that: Also includes: A pilot-operated pressure reducing valve (11), wherein the pilot-operated pressure reducing valve (11) is connected to the filter device (10), and the pilot-operated pressure reducing valve (11) is connected to a high-pressure oil port.

7. The servo valve pressure maintaining and oil replenishing system according to claim 1, characterized in that: Also includes: An energy storage module is used to provide hydraulic oil to the servo valve (1).

8. The pressure maintaining and oil replenishing system of the servo valve according to claim 7, characterized in that: The energy storage module comprises: an accumulator (12), a third safety valve (13), a first ball valve (14) and a second ball valve (15); the third safety valve (13), the first ball valve (14) and the second ball valve (15) are all connected to the accumulator (12); the first ball valve (14) is connected to the high-pressure oil port; the second ball valve (15) and the third safety valve (13) are both connected to the pilot oil drain port.

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