A hydraulic cylinder assembly structure suitable for servo valve control

Abstract

This invention relates to a hydraulic cylinder assembly, and more particularly to a hydraulic cylinder assembly structure suitable for servo valve control. The invention provides a hydraulic cylinder assembly structure suitable for servo valve control that can simultaneously perform forming and punching on workpieces, and has high driving efficiency under no-load conditions. A hydraulic cylinder assembly structure suitable for servo valve control includes a large hydraulic cylinder, a filling valve, a large piston rod, a plunger cylinder, a small oil chamber, and a retaining ring. A filling valve is installed at the bottom of the large hydraulic cylinder, and a large piston rod is located inside the large hydraulic cylinder. A plunger cylinder is connected to the bottom of the large hydraulic cylinder. Oil is filled into the plunger cylinder to improve the movement efficiency of the large piston rod. The plunger cylinder is hollow inside. This invention first fills the plunger cylinder with oil through a pipeline by starting an oil supply device. The oil flows upward into the small oil chamber through the hollow part in the middle of the plunger cylinder. Because the internal space of the plunger cylinder is small, the required oil flow rate is small, and the plunger cylinder can be filled in a short time, thus improving the movement efficiency of the large piston rod.

Description

Technical Field

[0001] This invention relates to a hydraulic cylinder assembly, and more particularly to a hydraulic cylinder assembly structure suitable for servo valve control. Background Technology

[0002] A hydraulic cylinder is an actuator in a hydraulic transmission system. It is an energy conversion device that converts hydraulic energy into mechanical energy and is used to drive working mechanisms to perform linear reciprocating motion or reciprocating oscillation. Hydraulic cylinders are required for punching and punching during the processing of hardware parts.

[0003] CNC stamping machines are generally used for stamping metal parts. The CNC control module controls the hydraulic cylinder to drive the stamping die to complete the stamping of the workpiece. The existing single hydraulic cylinder cannot simultaneously form and punch the workpiece. Moreover, because ordinary stamping hydraulic cylinders are large, a large flow of oil is required to achieve a certain speed. The hydraulic cylinder piston has low driving efficiency when unloaded, which affects the stamping efficiency. In addition, the selected servo valve has a large diameter and volume, which affects the control accuracy of the servo valve. Summary of the Invention

[0004] (1) Technical problems to be solved

[0005] In order to overcome the shortcomings of existing technologies, such as the inability of a single hydraulic cylinder to simultaneously form and punch a workpiece, the large oil flow required by the hydraulic cylinder, the low driving efficiency of the hydraulic cylinder piston under no-load conditions, and the impact on the control accuracy of the servo valve, the present invention aims to provide a hydraulic cylinder assembly structure that can simultaneously form and punch a workpiece, has high driving efficiency under no-load conditions, and is suitable for servo valve control.

[0006] (2) Technical solution

[0007] To address the aforementioned technical problems, this invention provides a hydraulic cylinder assembly structure suitable for servo valve control, comprising a large hydraulic cylinder, a filling valve, a large piston rod, a plunger cylinder, a small oil chamber, a fixing ring, a limiting ring, a large oil chamber, an oil guide channel, a small piston rod, and an automatic opening and closing mechanism. The filling valve is installed at the bottom of the large hydraulic cylinder, and the large piston rod is located inside the large hydraulic cylinder. A plunger cylinder is connected to the bottom of the large hydraulic cylinder, and oil is filled into the plunger cylinder to improve the movement efficiency of the large piston rod. The plunger cylinder is hollow, and this hollow portion is used for oil flow. A small oil chamber, which seals with the plunger cylinder, is located in the lower part of the large piston rod. The plunger cylinder extends into the small oil chamber. A fixed ring is connected to the upper end of the oil chamber, and a limiting ring is provided in the upper part of the large oil cylinder. The limiting ring is used to limit the movement distance of the large piston rod. A large oil chamber is provided in the upper part of the large piston rod, and oil guide channels are evenly opened in the lower part of the large piston rod. The oil guide channels are connected to the large oil chamber. A small piston rod is movably installed in the large oil chamber. An automatic opening and closing mechanism is installed on the fixed ring. The upper and lower parts of the automatic opening and closing mechanism are located in the lower part of the large oil chamber and inside the piston cylinder, respectively. When the large piston rod extends to its limit distance and resets, it controls the opening and closing of the automatic opening and closing mechanism, respectively. When the automatic opening and closing mechanism is opened, the oil flows through the large oil chamber and the oil guide channels to push the small piston rod to extend.

[0008] Preferably, the automatic opening and closing mechanism includes a drive assembly, a turntable, a movable gate, and a fixed gate. The turntable is rotatably connected to the top of the fixed ring. The lower part of the large oil chamber is movably provided with a movable gate and a fixed gate is fixedly connected to it. The movable gate is connected to the turntable. The drive assembly is provided between the plunger cylinder and the turntable. The drive assembly is used to drive the turntable and the movable gate to rotate, so as to disconnect and open the oil passage between the large oil chamber and the oil guide channel.

[0009] Preferably, the drive assembly includes a guide tube, a fluid passage tube, and pins. A guide groove is formed on the inner wall of the plunger cylinder, and the guide groove is larger than the hollow part of the plunger cylinder. A guide tube is slidably provided in the guide groove, and a fluid passage tube is fixedly connected in the guide tube. Through holes are evenly spaced on the upper part of the fluid passage tube. The upper end of the fluid passage tube passes through the fixed ring and the center of the turntable. Multiple pins are evenly spaced on the upper end of the fluid passage tube. The turntable has oblique holes that are adapted to the pins evenly spaced on the circumference.

[0010] Preferably, it also includes a positioning magnetic column and an iron block. The top of the liquid passage pipe is connected to the iron block, the bottom of the small piston rod is connected to the positioning magnetic column, and the movable gate and the fixed gate are both provided with shaft holes that are compatible with the positioning magnetic column. The iron block is located below the positioning magnetic column, and the positioning magnetic column is used to attract the iron block so that the liquid passage pipe moves upward and resets.

[0011] Preferably, it further includes a first return spring and a second return spring. The first return spring is provided between the lower part of the large piston rod and the limiting ring, and the first return spring is sleeved on the outside of the large piston rod. The second return spring is connected between the lower part of the small piston rod and the top of the large oil chamber, and the second return spring is sleeved on the outside of the small piston rod.

[0012] Preferably, it also includes a large retaining ring and a small retaining ring, with the large retaining ring connected to the lower outer part of the large piston rod and the small retaining ring connected to the top of the large oil chamber.

[0013] Preferably, it also includes an elastic retaining ring. The bottom of the small piston rod has a groove, and an elastic retaining ring is connected between the top of the groove and the top of the fixed gate plate. The elastic retaining ring is sleeved on the outside of the positioning magnetic column and is used to prevent the oil from contacting the positioning magnetic column.

[0014] Preferably, a gap is left between the top of the fixed gate and the bottom of the small piston rod.

[0015] (3) Beneficial effects

[0016] This invention first injects oil into the plunger cylinder through a pipeline by activating the oil supply device. The oil flows upward into the small oil chamber through the hollow part in the middle of the plunger cylinder. Because the internal space of the plunger cylinder is small, the required oil flow rate is small, which can fill the plunger cylinder in a short time. Therefore, it can improve the efficiency of the large piston rod movement. Moreover, the required servo valve has a small diameter and volume, which can ensure the control accuracy of the servo valve. Activating the oil supply device to inject oil into the large oil cylinder pushes the large piston rod to move, while the small piston rod does not move. When the large piston rod and the large oil cylinder move to the limit distance to complete the first stamping, the opening and closing mechanism immediately opens, and oil enters the large oil chamber and pushes the small piston rod to move upward. The workpiece is then stamped a second time through a secondary stamping die. This can solve the technical problem in the prior art that a single oil cylinder cannot simultaneously form and punch a workpiece. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0018] Figure 2 This is a cross-sectional view of the overall structure of the present invention.

[0019] Figure 3 This is a cross-sectional view of a partial structure of the present invention.

[0020] Figure 4 This is a cross-sectional view of the automatic opening and closing mechanism of the present invention.

[0021] Figure 5 This is a partial three-dimensional structural diagram of the automatic opening and closing mechanism of the present invention.

[0022] Figure 6 This is an exploded view of the automatic opening and closing mechanism of the present invention.

[0023] Figure 7 This is a three-dimensional structural diagram of the positioning magnetic column and iron block components of the present invention.

[0024] Figure 8 This is a three-dimensional structural diagram of the fixed gate and elastic retaining ring and other components of the present invention.

[0025] The labels in the attached diagram are as follows: 1-Large oil cylinder, 2-Filling valve, 3-Large piston rod, 4-Plunger cylinder, 5-Small oil chamber, 6-Fixing ring, 7-Limiting ring, 8-Large oil chamber, 9-Oil guide channel, 10-Small piston rod, 11-Automatic opening and closing mechanism, 111-Drive assembly, 112-Turntable, 113-Modible gate, 114-Fixing gate, 1111-Guide groove, 1112-Guide tube, 1113-Liquid passage tube, 1114-Through hole, 1115-Pin rod, 1116-Angled hole, 12-First return spring, 13-Second return spring, 14-Large retaining ring, 15-Small retaining ring, 16-Positioning magnetic column, 17-Iron block, 18-Groove, 19-Elastic retaining ring. Detailed Implementation

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

[0027] Example 1

[0028] A hydraulic cylinder assembly structure suitable for servo valve control, such as Figures 1-3 As shown, the device includes a large oil cylinder 1, filling valves 2, a large piston rod 3, a plunger cylinder 4, a small oil chamber 5, a fixing ring 6, a limit ring 7, a large oil chamber 8, an oil guide channel 9, a small piston rod 10, and an automatic opening and closing mechanism 11. Four filling valves 2 are evenly spaced around the bottom of the large oil cylinder 1. The large piston rod 3 is movably mounted inside the large oil cylinder 1. The plunger cylinder 4 is bolted to the bottom of the large oil cylinder 1. Oil is filled into the plunger cylinder 4 to improve the moving efficiency of the large piston rod 3. The plunger cylinder 4 is hollow, and this hollow part is circular and used for oil flow. A small oil chamber 5 is provided in the lower part of the large piston rod 3, which seals with the plunger cylinder 4. The plunger cylinder 4 passes into the small oil chamber 5, and a fixing ring 6 is connected to the upper end of the small oil chamber 5. A limit ring 7 is integrally installed in the upper part of the large oil cylinder 1. The limit ring 7 is used to limit the movement distance of the large piston rod 3. A large oil chamber 8 is provided in the upper part of the large piston rod 3. Four oil guide channels 9 are evenly opened in the lower part of the large piston rod 3, penetrating its bottom. The top of the oil guide channels 9 is connected to the large oil chamber 8. A small piston rod 10 is movably installed in the large oil chamber 8. An automatic opening and closing mechanism 11 is installed on the fixed ring 6. The upper and lower parts of the automatic opening and closing mechanism 11 are located in the lower part of the large oil chamber 8 and inside the plunger cylinder 4, respectively. When the large piston rod 3 extends to its limit distance and resets, it controls the automatic opening and closing mechanism 11 to open and close, respectively. When the automatic opening and closing mechanism 11 opens, the oil flows through the large oil chamber 8 and the oil guide channels 9 to push the small piston rod 10 to extend.

[0029] When using this hydraulic cylinder assembly to stamp a workpiece, install the assembly on a CNC stamping machine. The large piston rod 3 and the small piston rod 10 are connected to the primary stamping die and the secondary stamping die, respectively. The plunger cylinder 4 and the filling valve 2 are connected to the servo valve, the oil supply equipment, and the oil tank through pipelines. When the cylinder is unloaded, open the servo valve and start the oil supply equipment to first fill the plunger cylinder 4 with high-pressure oil through the pipelines. The high-pressure oil flows upward into the small oil chamber 5 through the hollow part in the middle of the plunger cylinder 4. Because the internal space of the plunger cylinder 4 is small, less high-pressure oil is required, which can fill the plunger cylinder 4 in a short time, thus improving the efficiency of the movement of the large piston rod 3. After the small oil chamber 5 is filled with high-pressure oil, it pushes the large piston rod 3 to move upward. When the piston rod moves upward, a negative pressure is generated inside the large hydraulic cylinder 1. The oil in the oil tank is drawn into the large hydraulic cylinder 1 and the oil guide channel 9 through the pipelines and the filling valve 2. Since there are four filling valves 2, the large hydraulic cylinder 1 can be quickly replenished with oil. When the primary stamping die and the secondary stamping die are connected... After the workpiece surface contacts, simply filling the plunger cylinder 4 with high-pressure oil is insufficient to push the large piston rod 3 to press the workpiece. At this time, the oil supply equipment fills the large oil cylinder 1 with high-pressure oil through the pipeline and the filling valve 2. The high-pressure oil pushes the large piston rod 3 to continue moving upward. The four filling valves 2 can accelerate the filling and ensure the moving efficiency of the large piston rod 3. When the large piston rod 3 moves to the limit distance, the workpiece completes the first pressing. At this time, the opening and closing mechanism automatically opens, and the high-pressure oil in the oil guide channel 9 and the large oil cylinder 1 enters the large oil chamber 8, pushing the small piston rod 10 to move upward. The workpiece is then pressed a second time through the secondary pressing die. After the workpiece is pressed, the oil supply equipment is started to suck the oil in the plunger cylinder 4 back to the oil tank. The large piston rod 3 and the small piston rod 10, under their own weight, push the oil in the large oil cylinder 1 and the large oil chamber 8 back to the oil tank. The oil flows back to the oil tank through the pipeline. After the large piston rod 3 and the small piston rod 10 are reset, the automatic opening and closing mechanism 11 closes, and then the oil supply equipment is turned off.

[0030] Example 2

[0031] Based on Example 1, such as Figures 2-4 As shown, the automatic opening and closing mechanism 11 includes a drive assembly 111, a turntable 112, a movable gate 113, and a fixed gate 114. The turntable 112 is rotatably connected to the top of the fixed ring 6. The lower part of the large oil chamber 8 is movably provided with a movable gate 113 and a fixed gate 114 is fixedly connected. Both the movable gate 113 and the fixed gate 114 have staggered liquid guide holes. The movable gate 113 is located below the fixed gate 114 and is connected to the turntable 112. The drive assembly 111 is provided between the plunger cylinder 4 and the turntable 112. The drive assembly 111 is used to drive the turntable 112 and the movable gate 113 to rotate, so as to disconnect and open the oil passage between the large oil chamber 8 and the oil guide channel 9. A gap is left between the top of the fixed gate 114 and the bottom of the small piston rod 10 to ensure the contact area between the high-pressure oil and the small piston rod 10.

[0032] like Figures 4-6 As shown, the drive assembly 111 includes a guide tube 1112, a fluid passage tube 1113, and pins 1115. The inner wall of the plunger cylinder 4 has a guide groove 1111, which is larger than the hollow part of the plunger cylinder 4. The guide tube 1112 is slidably arranged inside the guide groove 1111. The guide tube 1112 is hollow inside. The hollow part of the guide tube 1112 is connected to the fluid passage tube 1113 by welding. The upper part of the fluid passage tube 1113 has through holes 1114 evenly spaced around its circumference. The upper end of the fluid passage tube 1113 passes through the fixing ring 6 and the center of the turntable 112. The fixing ring 6 is slidably connected to the fluid passage tube 1113. The upper end of the fluid passage tube 1113 is evenly spaced around its circumference with four pins 1115. The turntable 112 has four oblique holes 1116 evenly spaced around its circumference, which are adapted to the four pins 1115 respectively.

[0033] like Figure 7 As shown, it also includes a positioning magnetic column 16 and an iron block 17. The top of the liquid passage pipe 1113 is connected to the iron block 17, and the bottom of the small piston rod 10 is connected to the positioning magnetic column 16. The movable gate plate 113 and the fixed gate plate 114 both have shaft holes that are adapted to the positioning magnetic column 16 in the middle. The positioning magnetic column 16 passes through the shaft hole, and the iron block 17 is located directly below the positioning magnetic column 16. The positioning magnetic column 16 is used to attract the iron block 17 so that the liquid passage pipe 1113 moves upward and resets.

[0034] Initially, the positioning magnetic column 16 attracts the iron block 17, and the pin 1115 is located at the highest point of the inclined hole 1116. When the high-pressure oil is filled into the plunger cylinder 4, the high-pressure oil flows into the small oil chamber 5 through the liquid pipe 1113 and the through hole 1114. When the large piston rod 3 moves upward, the liquid pipe 1113 and the guide pipe 1112 move upward accordingly. When the guide pipe 1112 moves to the upper end of the guide groove 1111, the guide pipe 1112 and the liquid pipe 1113 can no longer move upward. Under the action of oil pressure, the large piston rod 3 continues to move upward, and the positioning magnetic column 16 disengages from the iron block 17. Under the cooperation of the pin 1115 and the inclined hole 1116, the turntable 112 rotates, causing the movable gate 113 to rotate, so that the liquid guide hole on the movable gate 113 corresponds to the liquid guide hole on the fixed gate 114. The high-pressure oil flows into the large oil chamber 8 through the oil guide channel 9 and pushes the small piston rod 10 to move upward. When the small piston rod 10 and the large piston rod 3 are reset downwards, the positioning magnetic column 16 attracts the iron block 17 upwards, the guide tube 1112 and the liquid passage tube 1113 move upwards, and the pin rod 1115 moves upwards accordingly. Through the cooperation with the inclined hole 1116, the guide tube 1112 and the movable gate 113 rotate and reset, and the liquid guide hole on the movable gate 113 moves away from the liquid guide hole on the fixed gate 114.

[0035] Example 3

[0036] Based on Example 2, such as Figure 2 As shown, it also includes a first return spring 12 and a second return spring 13. The first return spring 12 is provided between the lower part of the large piston rod 3 and the limiting ring 7. The first return spring 12 is sleeved on the outside of the large piston rod 3. The second return spring 13 is connected between the lower part of the small piston rod 10 and the top of the large oil chamber 8. The second return spring 13 is sleeved on the outside of the small piston rod 10.

[0037] When the large piston rod 3 moves upward, the first return spring 12 is compressed and stores energy. When the small piston rod 10 moves upward, the second return spring 13 is compressed and stores energy. When the oil supply device is started to draw the oil in the plunger cylinder 4 back to the oil tank, the return speed of the large piston rod 3 and the small piston rod 10 can be accelerated under the action of the first return spring 12 and the second return spring 13, thereby improving the working efficiency of this cylinder assembly.

[0038] like Figure 2 and Figure 3 As shown, it also includes a large retaining ring 14 and a small retaining ring 15. The large retaining ring 14 is connected to the lower outer part of the large piston rod 3, and the small retaining ring 15 is connected to the top of the large oil chamber 8.

[0039] When the first return spring 12 and the second return spring 13 are compressed, the first return spring 12 and the second return spring 13 retract into the large retaining ring 14 and the small retaining ring 15 respectively, which can ensure the stability of the first return spring 12 and the second return spring 13 when compressed. The large retaining ring 14 and the small retaining ring 15 can limit the maximum distance of the upward movement of the large piston rod 3 and the small piston rod 10 respectively.

[0040] like Figure 8 As shown, it also includes an elastic retaining ring 19. The bottom center of the small piston rod 10 has a groove 18. The groove 18 is located outside the magnetic column 16. An elastic retaining ring 19 is connected between the top of the groove 18 and the top of the fixed gate plate 114. The elastic retaining ring 19 is sleeved on the outside of the positioning magnetic column 16. The elastic retaining ring 19 is used to prevent the oil from contacting the positioning magnetic column 16.

[0041] When the oil enters the large oil chamber 8, the elastic retaining ring 19 can prevent the oil from contacting the positioning magnetic column 16 and prevent the oil from flowing downward through the shaft hole in the middle of the fixed gate 114. When the elastic retaining ring 19 contracts, the groove 18 can accommodate the elastic retaining ring 19.

[0042] The above-described embodiments are merely preferred embodiments of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications, improvements, and substitutions without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A hydraulic cylinder assembly structure suitable for servo valve control, comprising a large hydraulic cylinder (1), a filling valve (2), and a large piston rod (3), wherein the filling valve (2) is installed at the bottom of the large hydraulic cylinder (1), and the large piston rod (3) is provided inside the large hydraulic cylinder (1), characterized in that, It also includes a plunger cylinder (4), a small oil chamber (5), a fixing ring (6), a limiting ring (7), a large oil chamber (8), an oil guide channel (9), a small piston rod (10), and an automatic opening and closing mechanism (11). The plunger cylinder (4) is connected to the bottom of the large oil cylinder (1). Oil is filled into the plunger cylinder (4) to improve the moving efficiency of the large piston rod (3). The plunger cylinder (4) is hollow inside, and the hollow part is used for oil flow. The lower part of the large piston rod (3) is provided with a small oil chamber (5) that seals with the plunger cylinder (4). The plunger cylinder (4) passes into the small oil chamber (5). The upper end of the small oil chamber (5) is connected with a fixing ring (6). The upper part of the large oil cylinder (1) is provided with a limiting ring (7). The limiting ring (7) is used to limit the large piston. The moving distance of the rod (3) is as follows: the upper part of the large piston rod (3) is provided with a large oil chamber (8), the lower part of the large piston rod (3) is uniformly opened with an oil guide channel (9) in the circumference, the oil guide channel (9) is connected to the large oil chamber (8), the small piston rod (10) is movably provided in the large oil chamber (8), and an automatic opening and closing mechanism (11) is installed on the fixed ring (6). The upper and lower parts of the automatic opening and closing mechanism (11) are located in the lower part of the large oil chamber (8) and the inside of the plunger cylinder (4), respectively. When the large piston rod (3) extends to the limit distance and resets, it controls the automatic opening and closing mechanism (11) to open and close, respectively. When the automatic opening and closing mechanism (11) opens, it allows the oil to pass through the large oil chamber (8) and the oil guide channel (9) to push the small piston rod (10) to extend. The automatic opening and closing mechanism (11) includes a drive assembly (111), a turntable (112), a movable gate (113), and a fixed gate (114). The turntable (112) is rotatably connected to the top of the fixed ring (6). The lower part of the large oil chamber (8) is movably provided with a movable gate (113) and a fixed gate (114) is fixedly connected. The movable gate (113) is connected to the turntable (112). The drive assembly (111) is provided between the plunger cylinder (4) and the turntable (112). The drive assembly (111) is used to drive the turntable (112) and the movable gate (113) to rotate, so as to realize the disconnection and opening of the oil passage between the large oil chamber (8) and the oil guide channel (9). The drive assembly (111) includes a guide tube (1112), a fluid passage tube (1113), and a pin (1115). The inner wall of the plunger cylinder (4) has a guide groove (1111). The guide groove (1111) is larger than the hollow part of the plunger cylinder (4). The guide tube (1112) is slidably provided in the guide groove (1111). The fluid passage tube (1113) is fixedly connected in the guide tube (1112). The upper part of the fluid passage tube (1113) has through holes (1114) evenly spaced around the circumference. The upper end of the fluid passage tube (1113) passes through the fixed ring (6) and the center of the turntable (112). The upper end of the fluid passage tube (1113) is connected to multiple pins (1115) evenly spaced around the circumference. The turntable (112) has oblique holes (1116) evenly spaced around the circumference that are adapted to the pins (1115).

2. The hydraulic cylinder assembly structure suitable for servo valve control according to claim 1, characterized in that, It also includes a positioning magnetic column (16) and an iron block (17). The top of the liquid passage pipe (1113) is connected to the iron block (17), and the bottom of the small piston rod (10) is connected to the positioning magnetic column (16). The movable gate (113) and the fixed gate (114) both have shaft holes that are compatible with the positioning magnetic column. The iron block (17) is located below the positioning magnetic column (16). The positioning magnetic column (16) is used to attract the iron block (17) so that the liquid passage pipe (1113) moves upward and resets.

3. The cylinder assembly structure suitable for servo valve control according to claim 1, characterized in that, It also includes a first reset spring (12) and a second reset spring (13). The first reset spring (12) is provided between the lower part of the large piston rod (3) and the limiting ring (7). The first reset spring (12) is sleeved on the outside of the large piston rod (3). The second reset spring (13) is connected between the lower part of the small piston rod (10) and the top of the large oil chamber (8). The second reset spring (13) is sleeved on the outside of the small piston rod (10).

4. The hydraulic cylinder assembly structure suitable for servo valve control according to claim 1, characterized in that, It also includes a large retaining ring (14) and a small retaining ring (15). The large retaining ring (14) is connected to the lower part of the outer side of the large piston rod (3), and the small retaining ring (15) is connected to the top of the large oil chamber (8).

5. The hydraulic cylinder assembly structure suitable for servo valve control according to claim 1, characterized in that, It also includes an elastic retaining ring (19), a groove (18) at the bottom of the small piston rod (10), an elastic retaining ring (19) connecting the top of the groove (18) and the top of the fixed gate plate (114), the elastic retaining ring (19) being sleeved on the outside of the positioning magnetic column (16), the elastic retaining ring (19) being used to prevent the oil from contacting the positioning magnetic column (16).

6. The hydraulic cylinder assembly structure suitable for servo valve control according to claim 1, characterized in that, A gap is left between the top of the fixed gate (114) and the bottom of the small piston rod (10) to increase the contact area between the small piston rod (10) and the high-pressure oil, and to ensure the upward thrust of the small piston rod (10).

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