High frequency response cartridge valve using hydraulic screw

Abstract

This invention relates to a high-frequency response cartridge valve employing a hydraulic screw, comprising a servo drive mechanism, a control screw, and a cartridge valve core. The control screw is internally connected to the upper part of the cartridge valve core, and the upper end of the control screw is connected to the servo drive mechanism. The control screw has an oil-passing spiral groove. When the servo drive mechanism rotates, the control screw with the spiral oil-passing groove, in conjunction with the cartridge valve core to form a throttling orifice, jointly pushes the cartridge valve core, which has an area difference feature, to perform linear displacement, thereby precisely controlling the valve core opening of the high-frequency response cartridge valve. This invention, through this mechanical drive and feedback structure, converts the angular displacement generated by the rotation of the servo motor into the axial linear displacement of the cartridge valve core. The rotation angle of the servo motor and the axial movement distance of the valve core are linearly related, enabling precise control and rapid response of the main valve position of the high-frequency response cartridge valve.

Description

Technical Field

[0001] This invention relates to a hydraulically driven cover-type cartridge valve, and more particularly to a high-frequency response cartridge valve employing a hydraulic screw. Background Technology

[0002] High-frequency response cartridge valves were introduced abroad in the 1970s and have undergone decades of theoretical and product development and improvement. The product range covers nine diameters from DN16 to DN160, with two to three types of valve ports. The valve mounting holes conform to the relevant requirements of GB / T 2877 (ISO7368.2) standards. The frequency response is significantly improved compared to earlier products. The pilot valve can be controlled by a servo valve or a proportional valve. For high-frequency response cartridge valves with high frequency response requirements, a servo valve is used as the pilot valve; for those with lower frequency response requirements, a proportional valve can be used. Furthermore, most high-frequency response cartridge valves currently integrate electronic controllers with both analog and digital control capabilities, and some manufacturers also offer controllers with bus control functionality.

[0003] However, regardless of whether a servo valve or a proportional valve is used as the pilot control valve, there are high requirements for the valve's machining accuracy and the cleanliness of the oil, which leads to a decrease in the overall reliability of high-frequency response cartridge valves.

[0004] In addition, an LVDT displacement sensor needs to be connected to the main valve core of the high-frequency response cartridge valve and the signal needs to be fed back to the controller of the pilot valve to form an electrical closed loop. Internal and external electromagnetic interference needs to be prevented. Therefore, the structure and control of this high-frequency response cartridge valve are relatively complex. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a high-frequency response cartridge valve using a hydraulic screw to achieve high-precision position and fast response control of the cartridge valve main valve.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is: a high-frequency response cartridge valve using a hydraulic screw, comprising a servo drive mechanism, a control screw, and a cartridge valve core. The upper part of the cartridge valve core is internally connected to the control screw, and the upper end of the control screw is connected to the servo drive mechanism. The control screw is provided with an oil-passing spiral groove. When the servo drive mechanism rotates, the control screw with the spiral oil-passing groove and the cartridge valve core cooperate to form a throttling orifice, jointly pushing the cartridge valve core with the upper and lower area difference characteristics to perform linear displacement, thereby accurately controlling the valve core opening of the high-frequency response cartridge valve.

[0007] Furthermore, the servo drive mechanism is a servo motor, a stepper motor, or a rotary drive torque motor.

[0008] Furthermore, the high-frequency response cartridge valve also includes a cross-slider coupling, a pressure sealing seat, an angular contact ball bearing, a sealing assembly, a cover plate, an anti-rotation pin, a high-precision steel ball, and a cartridge valve sleeve. The servo drive mechanism is installed on the upper end face of the cover plate and is connected to a control screw through the cross-slider coupling. A pressure sealing seat is provided inside the upper end of the cover plate, and an angular contact ball bearing is installed at the lower end of the pressure sealing seat. A sealing assembly is installed between the cartridge valve core, the cover plate, and the cartridge valve sleeve.

[0009] Furthermore, a high-pressure port X and a low-pressure return port Y are respectively provided on the cover plate. The high-pressure port X is connected to the Pb cavity and the Pf cavity respectively, and the low-pressure return port Y is connected to the Pc cavity and the Pe cavity respectively.

[0010] Furthermore, the cover plate and the cartridge valve sleeve have five sections with different diameters forming an area difference. When the control screw rotates to connect the external control oil through the oil port X with the Pf and Pa chambers, the area difference generates a closing force that pushes the cartridge valve core to close axially, and the openings of the A and B valve ports on the cartridge valve sleeve decrease. When the control screw rotates to connect the Pa chamber back to the oil port Y, the force of the Pf chamber pushes the cartridge valve core 6 to open axially, and the openings of the A and B valve ports on the cartridge valve sleeve increase.

[0011] Furthermore, an anti-rotation pin is installed between the cover plate and the cartridge valve sleeve to prevent the valve sleeve and the cover plate from rotating.

[0012] Furthermore, the cross-section of the spiral oil passage on the control screw is triangular, trapezoidal, or arc-shaped, and the number of spiral grooves is a multiple of 2.

[0013] Furthermore, the cartridge valve core is provided with a valve sleeve hole that mates with the control screw, and four rectangular windows with flow passage are provided circumferentially, the cross-section of the rectangular windows being rhomboid, circular, or arc-shaped.

[0014] Furthermore, a high-precision steel ball is installed between the cartridge valve core and the cartridge valve sleeve.

[0015] Furthermore, the main valve port of the high-frequency response cartridge valve is a two-way, three-way, or four-way valve port structure.

[0016] The beneficial effects of this invention are:

[0017] 1. The servo motor has a fast response and high angle control accuracy, which improves the responsiveness and control accuracy of the valve compared to traditional high-frequency response cartridge valves;

[0018] 2. The valve core position uses mechanical feedback, eliminating the interference often found in electrical feedback loops, resulting in higher reliability;

[0019] 3. Compared with the traditional structure that uses servo valves or proportional valves as pilot control valves, it has less throttling loss, higher resistance to contamination, and is more green and energy-saving;

[0020] 4. The structure is simpler, operation and maintenance are more convenient, and maintenance costs are lower. Attached Figure Description

[0021] Figure 1 This is a cross-sectional view of the high-frequency response cartridge valve using a hydraulic screw according to the present invention;

[0022] Figure 2 This is a schematic diagram of the high-frequency response cartridge valve using a hydraulic screw according to the present invention;

[0023] Figure 3 This is a schematic diagram of the high-frequency response cartridge valve using a hydraulic screw according to the present invention.

[0024] Reference numerals: 1. Servo motor, 2. Cross-slider coupling, 3. Pressing seal seat, 4. Control screw, 5. Angular contact ball bearing, 6. Cartridge valve core, 7. Sealing assembly, 8. Cover plate, 9. Anti-rotation pin, 10. High-precision steel ball, 11. Cartridge valve sleeve; A. Cartridge valve main valve bottom cavity oil port, B. Cartridge valve main valve side cavity oil port, X. Cartridge valve external control oil port, Y. Cartridge valve return oil port. Detailed Implementation

[0025] To facilitate understanding of the present invention, a more detailed and comprehensive description is provided below, with accompanying drawings illustrating one embodiment. The present invention can be implemented in different forms and is not limited to this embodiment.

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] like Figure 1 As shown, the high-frequency response cartridge valve of the present invention using a hydraulic screw includes a servo motor 1, a cross-slider coupling 2, a clamping sealing seat 3, a control screw 4, an angular contact ball bearing 5, a cartridge valve core 6, a sealing assembly 7, a cover plate 8, an anti-rotation pin 9, a high-precision steel ball 10, and a cartridge valve sleeve 11. The servo motor 1 is installed on the upper end face of the cover plate 8. The two ends of the cross-slider coupling 2 are respectively connected to the extension shaft of the servo motor 1 and the control screw 4. The lower end of the clamping sealing seat 3 is equipped with an angular contact ball bearing 5. The portion of the control screw 4 with a helical groove is installed inside the cartridge valve core 6. A sealing assembly 7 is installed between the cartridge valve core 6, the cover plate 8, and the cartridge valve sleeve 11. A high-precision steel ball 10 is installed between the cartridge valve core 6 and the cartridge valve sleeve 11. The cartridge valve sleeve 11 is installed inside the cover plate 8 and is equipped with the sealing assembly 7 for end face sealing, and is installed between the cartridge valve core 6 and the cover plate 8.

[0028] In addition, a sealing assembly 7 is installed between the cartridge valve core 6 and the cover plate 8 to isolate the two control chambers Pe and Pf, which are used to adjust the effective working area of ​​the cartridge valve core 6.

[0029] In addition, such as Figure 1 and Figure 2 As shown, the Pd cavity is connected to the oil port A of the bottom cavity of the high-frequency response cartridge valve through the middle channel of the cartridge valve core 6. The Pg cavity is the oil port B of the side cavity of the high-frequency response cartridge valve. The Pa cavity is the control cavity of the cartridge valve core 6. A high-pressure port X and a low-pressure return port Y are respectively provided on the cover plate body 8. The high-pressure port X is connected to the Pb cavity and the Pf cavity respectively. The low-pressure return port Y is connected to the Pc cavity and the Pe cavity respectively.

[0030] Furthermore, the structure with five sections of different diameters d1 to d5 forms an area difference. The hydraulic oil acts on this area difference, generating thrust in different directions. When the control screw 4 rotates to the point where the external control oil port X connects with the Pf chamber, the spiral groove of the control screw 4, and the Pa chamber, the area difference generates a closing force, pushing the cartridge valve core 6 to close axially. At this time, the openings of valve ports A and B decrease. When the control screw 4 rotates to the point where the Pa chamber connects back to the oil port Y, the force from the Pf chamber pushes the cartridge valve core 6 to open axially, at which time the openings of valve ports A and B increase.

[0031] In addition, the angular contact ball bearing 5 is used to balance the axial force borne by the control screw 4 when the Pa cavity is under high pressure.

[0032] In addition, an anti-rotation pin is installed between the cover plate body 8 and the cartridge valve sleeve 11 to prevent the valve sleeve and the cover plate body from rotating.

[0033] In addition, a high-precision steel ball 10 is installed between the cartridge valve core 6 and the cartridge valve sleeve 11 to prevent the cartridge valve core 6 from rotating during axial movement.

[0034] In addition, the cartridge valve core 6 is provided with a valve sleeve hole that mates with the control screw 4, and is provided with four rectangular windows for flow passage. Through the spiral groove provided by the control screw 4, the connection or closure of the Pb, Pc chambers and the Pa chamber can be realized.

[0035] Furthermore, viewed from the servo motor 1 end, when the servo motor 1 rotates clockwise, the control screw 4 rotates synchronously, forming a throttling orifice between it and the cartridge valve core 6. The hydraulic oil in the control chamber Pa flows back to the low-pressure chamber Pc through this orifice. At this time, the cartridge valve core 6 rises upwards due to hydraulic pressure until the throttling orifice closes, at which point the cartridge valve core 6 stops moving. The upward distance depends on the angular rotation of the servo motor, which in turn depends on the angular rotation of the servo motor and the control screw, determined by the angular position control signal applied by the servo motor controller.

[0036] Furthermore, viewed from the servo motor end, the servo motor rotates counterclockwise, and after the control screw 4 rotates synchronously, a throttling orifice is formed between it and the cartridge valve core 6. Hydraulic oil in the high-pressure chamber Pb flows into the control chamber Pa through this orifice. At this time, the cartridge valve core 6 closes downwards due to hydraulic pressure until the aforementioned throttling orifice closes, at which point the cartridge valve core 6 stops operating. The downward closing distance depends on the angular rotation of the servo motor, which in turn depends on the angular rotation of the servo motor and the control screw, and is determined by the angular position control signal applied by the servo motor controller.

[0037] In addition, the servo motor 1 can accept fast time-varying signals of angular position, and the running speed of the cartridge valve core 6 changes synchronously. The flow openings of the A and B oil ports of the lower cartridge valve core 6 change, thereby realizing the rapid adjustment of the position of the cartridge valve core 6 and the flow rate of the valve ports A and B.

[0038] The above embodiments are merely examples illustrating one of the several cases of the present invention and should not be construed as limiting the patent of the present invention. Based on these embodiments, the high-frequency response cartridge valve of the present invention can be further improved. Therefore, the scope of patent protection of the present invention should be determined by the appended claims.

Claims

1. A high-frequency response cartridge valve employing a hydraulic screw, characterized in that: The device includes a servo drive mechanism, a control screw, a cartridge valve core, and a cover plate. The upper part of the cartridge valve core is internally connected to the control screw, and the upper end of the control screw is connected to the servo drive mechanism. The control screw has an oil-passing spiral groove. The cover plate has a high-pressure port X and a low-pressure return port Y. The high-pressure port X is connected to the Pb and Pf chambers, and the low-pressure return port Y is connected to the Pc and Pe chambers. The cover plate and the cartridge valve sleeve have five sections of different diameters forming an area difference. The cartridge valve core has a valve sleeve hole that mates with the control screw, and four rectangular windows with flow passage are provided circumferentially. When the servo drive mechanism rotates, the control screw with the spiral oil-passing groove and the cartridge valve core cooperate to form a throttling orifice, jointly pushing the cartridge valve core with the area difference feature to make linear displacement, thereby accurately controlling the valve core opening of the high-frequency response cartridge valve.

2. The high-frequency response cartridge valve using a hydraulic screw according to claim 1, characterized in that: The servo drive mechanism is a servo motor, a stepper motor, or a rotary drive torque motor.

3. The high-frequency response cartridge valve using a hydraulic screw according to claim 1, characterized in that: It also includes a cross-slider coupling, a clamping seal seat, an angular contact ball bearing, a sealing assembly, an anti-rotation pin, a high-precision steel ball, and a cartridge valve sleeve. The servo drive mechanism is installed on the upper end face of the cover plate body. The servo drive mechanism is connected to the control screw through the cross-slider coupling. A clamping seal seat is provided inside the upper end of the cover plate body. An angular contact ball bearing is installed at the lower end of the clamping seal seat. A sealing assembly is installed between the cartridge valve core, the cover plate body, and the cartridge valve sleeve.

4. The high-frequency response cartridge valve using a hydraulic screw according to claim 1, characterized in that: When the control screw rotates to connect the external control oil through the oil port X with the Pf and Pa chambers, the difference in the working area generates a closing force that pushes the cartridge valve core to close axially, and the openings of the A and B valve ports on the cartridge valve sleeve decrease; when the control screw rotates to connect the Pa chamber back to the oil port Y, the force of the Pf chamber pushes the cartridge valve core (6) to open axially, and the openings of the A and B valve ports on the cartridge valve sleeve increase.

5. The high-frequency response cartridge valve using a hydraulic screw according to claim 1, characterized in that: An anti-rotation pin is installed between the cover plate and the cartridge valve sleeve to prevent the valve sleeve and the cover plate from rotating.

6. The high-frequency response cartridge valve using a hydraulic screw according to claim 1, characterized in that: The cross-section of the spiral oil passage on the control screw is triangular, trapezoidal, or arc-shaped, and the number of spiral grooves is a multiple of 2.

7. The high-frequency response cartridge valve using a hydraulic screw according to claim 1, characterized in that: The rectangular window has a cross-section that is rhomboid, circular, or arc-shaped.

8. The high-frequency response cartridge valve using a hydraulic screw according to claim 1, characterized in that: A high-precision steel ball is installed between the cartridge valve core and the cartridge valve sleeve.

9. The high-frequency response cartridge valve employing a hydraulic screw according to any one of claims 1-8, characterized in that: The main valve port of the high-frequency response cartridge valve has a two-way, three-way, or four-way valve port structure.

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