An assembly and disassembly device for an internal expansion type locking hydraulic cylinder and a use method thereof

Abstract

The application provides an assembly and disassembly device and a use method for an internal expansion type locking hydraulic cylinder, which comprises an auxiliary cylinder, an installation oil inlet, a rod sealing structure and an end face locking and sealing assembly; one end of the auxiliary cylinder is a butt joint end of the internal expansion type locking hydraulic cylinder, and the end face locking and sealing assembly is used for locking and sealing the butt joint end of the auxiliary cylinder and an end part of the internal expansion type locking hydraulic cylinder; the other end of the auxiliary cylinder is provided with a piston rod through hole, and the rod sealing structure is arranged on the inner surface of the piston rod through hole to form a movable sealing structure; the installation oil inlet is arranged on the side of the auxiliary cylinder and communicates with the inside of the auxiliary cylinder, and is used for injecting hydraulic oil into the auxiliary cylinder; and the inner diameter of the auxiliary cylinder is greater than that of the internal expansion type locking hydraulic cylinder matched with the auxiliary cylinder. The scheme is suitable for the internal expansion type locking hydraulic cylinder, and can solve the unlocking problem caused by the movement of the piston and the difficulty in assembly and disassembly.

Description

Technical Field

[0001] This invention relates to the field of hydraulic cylinder technology, and more specifically, to an assembly and disassembly device and method for an internal expansion locking hydraulic cylinder. Background Technology

[0002] Traditional hydraulic cylinders typically use hydraulic locks to lock the stroke. The significant difference between internal expansion locking hydraulic cylinders and traditional hydraulic cylinders lies in the difference in locking method.

[0003] An internal expansion locking hydraulic cylinder is a type of hydraulic cylinder that uses an interference fit between the locking body on the piston and the cylinder barrel for stroke locking. The magnitude of the locking force depends on the size of the interference fit. The locking chamber of an internal expansion locking hydraulic cylinder is an independent cavity between the piston and the cylinder body. When the cylinder is working, high-pressure oil is introduced into the locking chamber, causing the cylinder barrel to expand by a certain amount. The interference fit between the locking body on the piston and the cylinder barrel decreases or becomes a clearance fit, unlocking the cylinder and allowing the piston to move freely.

[0004] Currently, internal expansion locking hydraulic cylinders have been widely used in various fields, but the installation, disassembly, and maintenance of internal expansion locking hydraulic cylinders still present significant challenges.

[0005] Traditional disassembly methods, such as the scheme disclosed in application number CN201380066863.2, invention title: device for assembling and disassembling hydraulic cylinders, provide a special disassembly tool, the core of which is the guidance and positioning of the piston rod. However, due to the presence of a locking body in the internal expansion locking hydraulic cylinder, the application of this traditional scheme is quite difficult.

[0006] Taking the installation process as an example, such as Figure 1 The diagram shows the structure of an internally expanding locking hydraulic cylinder. At the start of the installation process, the piston and locking body are outside the cylinder, meaning the closed, independent area between the piston's left and right seals and the cylinder body is open to the outside. The hydraulic cylinder cannot be unlocked in this position, so the piston cannot be installed into the cylinder. Similarly, during cylinder disassembly, disassembly cannot continue after the locking cavity is open to the outside. Furthermore, the cylinder locking force is generally around 10T, and forcibly installing or disassembling it at this point is very likely to cause cylinder scoring.

[0007] Based on the above problems, it is necessary to develop a dedicated assembly and disassembly device for internal expansion locking hydraulic cylinders to solve the locking problem caused by piston movement during assembly and disassembly.

[0008] In order to solve the above problems, people have been seeking an ideal technological solution. Summary of the Invention

[0009] The purpose of this invention is to address the shortcomings of existing technologies by providing a solution suitable for use in internal expansion locking hydraulic cylinders, which solves the locking problem caused by piston movement, and thus solves the assembly and disassembly problems of internal expansion locking hydraulic cylinders.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is: an assembly and disassembly device for an internally expanding locking hydraulic cylinder, comprising an auxiliary cylinder barrel, an oil injection port, a rod sealing structure, and an end face locking sealing assembly; One end of the auxiliary cylinder is the docking end of the internal expansion locking hydraulic cylinder, and the end face locking and sealing assembly is used to lock and seal the docking end of the auxiliary cylinder with the end of the internal expansion locking hydraulic cylinder. The other end of the auxiliary cylinder is provided with a piston rod passage hole, and the rod sealing structure is provided on the inner surface of the piston rod passage hole to form a movable sealing structure; The oil injection port is located on the side of the auxiliary cylinder and communicates with the inside of the auxiliary cylinder, and is used to inject hydraulic oil into the auxiliary cylinder. The inner diameter of the auxiliary cylinder is larger than the inner diameter of the internal expansion locking hydraulic cylinder that is adapted to it.

[0011] Based on the above, the end locking and sealing assembly includes a flange and connecting bolts disposed on the outside of the auxiliary cylinder barrel docking end. The connecting bolts cooperate with the flange to lock and fix the end of the internal expansion locking hydraulic cylinder.

[0012] Based on the above, the inner diameter of the auxiliary cylinder is 0.25-0.35 mm larger than the inner diameter of the cylinder of the internal expansion locking hydraulic cylinder that is adapted to it.

[0013] Based on the above, the end face of the auxiliary cylinder barrel docking end is provided with an end face sealing structure, which is used to seal with the end face of the internal expansion locking hydraulic cylinder.

[0014] Based on the above, the oil injection port is located in the area near the piston rod through hole.

[0015] Based on the above, the flange is connected and fixed to the auxiliary cylinder by means of threads, welding, or tight clamping.

[0016] Based on the above, the inner diameter of the auxiliary cylinder, in conjunction with the piston of the internally expanding locking hydraulic cylinder, forms a pressure-holding and sealing structure under a set pressure.

[0017] Based on the above, it also includes a hydraulic control unit, which includes a hydraulic pump, an oil suction port, a safety valve, an unloading valve, an oil output port, an accumulator, and a pressure gauge. The oil inlet of the hydraulic pump is connected to the oil suction port, and the oil outlet of the hydraulic pump is connected to the oil output port. The safety valve is used to protect the hydraulic pump, the unloading valve is used to unload the oil pressure, and the accumulator and pressure gauge are located at the oil output port. The oil output port is used to provide hydraulic oil during the assembly and disassembly of the internal expansion locking hydraulic cylinder assembly and disassembly device.

[0018] A method for installing an internally expanding locking hydraulic cylinder includes an assembly and disassembly device for the internally expanding locking hydraulic cylinder, and the cylinder is installed in the following manner: Part One: The piston and piston rod are pre-installed inside the auxiliary cylinder, and the mating end of the auxiliary cylinder is locked and sealed at the front end of the internal expansion locking hydraulic cylinder by the end face locking and sealing assembly. And make the piston and piston rod cooperate with the locking control mechanism of the internal expansion locking hydraulic cylinder; Part Two: Hydraulic oil is injected into the oil inlet of the auxiliary cylinder, driving the piston and piston rod to move inward into the hydraulic cylinder for locking. When the locking body in the piston moves to the splicing surface of the auxiliary cylinder and the internal expansion locking hydraulic cylinder, hydraulic oil is injected into the locking control port of the internal expansion locking hydraulic cylinder to unlock the piston; Continue injecting hydraulic oil into the installation port of the auxiliary cylinder to drive the piston and piston rod as a whole into the internal expansion locking hydraulic cylinder; Part Three: Disassemble the auxiliary cylinder and install the front cover of the internal expansion locking hydraulic cylinder into place.

[0019] A method for disassembling an internally expanding locking hydraulic cylinder includes an assembly and disassembly device for the internally expanding locking hydraulic cylinder, and disassembly is performed in the following manner: Part One: Disassemble the front cover of the internal expansion locking hydraulic cylinder and lock and seal the docking end of the auxiliary cylinder to the front end of the internal expansion locking hydraulic cylinder through the end face locking and sealing assembly. The piston rod of the internal expansion locking hydraulic cylinder passes through the piston rod through the hole in the auxiliary cylinder barrel; Part Two: Hydraulic oil is injected into the locking control port of the inward-expanding locking hydraulic cylinder to unlock the piston; Hydraulic oil is injected into the lower chamber of the inward-expanding locking hydraulic cylinder, driving the piston and piston rod to move as a whole toward the auxiliary cylinder until the piston and piston rod as a whole enter the auxiliary cylinder. When the locking body in the piston moves to the auxiliary cylinder, the hydraulic oil injected into the locking control port of the inward-expanding locking hydraulic cylinder is unloaded, and hydraulic oil continues to be injected into the lower chamber of the inward-expanding locking hydraulic cylinder until the piston and piston rod as a whole enter the required position of the auxiliary cylinder. Part Three: Disassemble the auxiliary cylinder; Remove the piston and piston rod from the auxiliary cylinder to complete the disassembly.

[0020] This invention has outstanding substantive features and significant progress compared to the prior art. Specifically, this invention designs an auxiliary cylinder with a larger inner diameter, enabling the piston of the internal expansion locking hydraulic cylinder to switch between the original cylinder and the auxiliary cylinder during installation and disassembly. Moreover, due to the larger inner diameter of the auxiliary cylinder, the locking effect of the locking body in the original piston can be eliminated or significantly weakened when inside the auxiliary cylinder, effectively reducing the difficulty of removing the piston, thereby realizing the installation and disassembly of the piston in the internal expansion locking hydraulic cylinder.

[0021] The size of the auxiliary cylinder's inner diameter also needs to take into account the pressure holding requirements. That is, when the piston enters the auxiliary cylinder, a certain degree of sealing can still be maintained between the piston and the inner wall of the auxiliary cylinder. The standard is that after oil is injected into the lower chamber or the auxiliary cylinder, the piston can continue to move without leakage, which meets the normal movement requirements of the piston and piston rod during the assembly and disassembly process.

[0022] Overall, during the assembly and disassembly process, no matter where the piston moves, the control chamber where the locking body is located in the piston can remain a closed cavity. This means that the locking hydraulic cylinder can be unlocked at any position, thus enabling installation and disassembly and solving the problem of the piston being difficult to unlock at critical positions in the traditional method. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the internal expansion locking hydraulic cylinder.

[0024] Figure 2 This is a schematic diagram of the assembly and disassembly device for the internal expansion locking hydraulic cylinder in this invention.

[0025] Figure 3 This is a schematic diagram illustrating the application state structure of the internal expansion locking hydraulic cylinder assembly and disassembly device in this invention.

[0026] Figure 4 This is a schematic diagram of the hydraulic control unit of the internal expansion locking hydraulic cylinder assembly and disassembly device in this invention.

[0027] In the diagram: 1. Auxiliary cylinder; 2. Oil inlet port; 3. Rod seal structure; 4. End face locking seal assembly; 5. Internal expansion locking hydraulic cylinder; 11. Piston; 12. Piston rod; 13. Piston through hole; 14. Flange; 15. Connecting bolts; 16. End face sealing groove; 21. Hydraulic pump; 22. Oil suction port; 23. Safety valve; 24. Unloading valve; 25. Oil output port; 26. Accumulator; 27. Pressure gauge; 51. Cylinder body; 52. Locking control port; 53. Front end cover; 54. Locking body; 55. Left piston seal; 56. Right piston seal; 57. Guide rod; 58. Guide rod seal; 59. Guide rod end face seal; 60. Upper chamber inlet; 61. Lower chamber inlet; 62. Control chamber. Detailed Implementation

[0028] The technical solution of the present invention will be further described in detail below through specific embodiments.

[0029] like Figures 2-4 As shown, an assembly and disassembly device for an internally expanding locking hydraulic cylinder includes an auxiliary cylinder barrel 1, an oil injection port 2, a rod sealing structure 3, and an end face locking sealing assembly 4.

[0030] Wherein, one end of the auxiliary cylinder 1 is the docking end of the internal expansion locking hydraulic cylinder 5, and the end face locking and sealing assembly 4 is used to lock and seal the docking end of the auxiliary cylinder 1 with the end of the internal expansion locking hydraulic cylinder 5. The inner diameter of the auxiliary cylinder 1 is larger than the inner diameter of the internal expansion locking hydraulic cylinder 5 that is adapted to it.

[0031] In this embodiment, the main function of the auxiliary cylinder 1 is to connect with the cylinder of the internal expansion locking hydraulic cylinder 5, so that the piston 11 and piston rod 12 can be transferred from the auxiliary cylinder 1 to the internal expansion locking hydraulic cylinder 5 to complete the installation process. When the piston 11 and piston rod 12 are disassembled, they can be transferred from the internal expansion locking hydraulic cylinder 5 to the auxiliary cylinder 1.

[0032] The inner diameter of the auxiliary cylinder 1 is larger than the inner diameter of the internal expansion locking hydraulic cylinder 5 that is adapted to it. The inner diameter of the auxiliary cylinder, together with the piston of the internal expansion locking hydraulic cylinder that is adapted to it, forms a pressure-holding and sealing structure under a set pressure.

[0033] The core of the pressure-holding sealing structure is to control the dimensional values ​​so that the inner wall of the auxiliary cylinder meets the condition of maintaining a certain pressure without leakage when used in conjunction with the piston seal, while also being able to release the locking effect of the locking body.

[0034] In this embodiment, the inner diameter of the auxiliary cylinder is 0.25-0.35 mm larger than the inner diameter of the cylinder of the internal expansion locking hydraulic cylinder that is adapted to it.

[0035] Its main purpose is to reduce the locking force after the piston enters the auxiliary cylinder 1, while maintaining a certain pressure to prevent oil leakage, so that the piston rod can move smoothly. Based on the auxiliary cylinder 1, the installation and disassembly of the piston 11 and piston rod 12 can be greatly reduced.

[0036] The other end of the auxiliary cylinder 1 is provided with a piston rod through hole 13. The rod sealing structure 3 is provided on the inner surface of the piston rod through hole 13 to form a movable sealing structure. In this embodiment, it is an annular sealing groove formed on the inner wall of the piston rod through hole 13. The specific number can be determined according to the specifications of the piston rod 12. In this embodiment, it is designed as two support ring grooves and one combined sealing ring groove.

[0037] The main function of the piston rod through the hole 13 is to ensure the stroke of the piston rod 12. It also needs to play the role of pressure holding, sealing and guiding, so that after the piston 11 enters the auxiliary cylinder 1, a closed pressure chamber can be formed.

[0038] The oil injection port 2 is located on the side of the auxiliary cylinder 1 and communicates with the inside of the auxiliary cylinder 1, and is used to inject hydraulic oil into the auxiliary cylinder 1.

[0039] Its main function is to push the piston 11 into the inward-expanding locking hydraulic cylinder 5 by injecting high-pressure oil into the installation oil port 2 during the installation of piston 11 and piston rod 12.

[0040] In this embodiment, the specific installation position is relatively close to the area of ​​the piston rod through hole 13, which can ensure that the piston 11 has the longest possible stroke in the auxiliary cylinder 1. In other embodiments, the specific position of the oil inlet 2 can be other required positions, and its specific position is mainly related to the stroke.

[0041] In this embodiment, the end locking and sealing assembly includes a flange 14 and a connecting bolt 15 disposed on the outside of the auxiliary cylinder docking end. The connecting bolt 15 cooperates with the flange 14 to lock and fix the end of the internal expansion locking hydraulic cylinder 5.

[0042] The main advantage is that the front cover locking structure of the original internal expansion locking hydraulic cylinder 5 is utilized, reducing the need for additional locking structures.

[0043] In this embodiment, flange 14 is connected and fixed to auxiliary cylinder 1 by threaded connection.

[0044] In other embodiments, the flange and the auxiliary cylinder can be connected and fixed by welding, integral molding, or tight clamping. The tight clamping method refers to setting a step at the end of the auxiliary cylinder, pressing the flange against the step, and locking it to the front end face of the internal expansion locking hydraulic cylinder with bolts.

[0045] Since the piston 11 needs to pass through the joint between the auxiliary cylinder 1 and the original cylinder 51 during the assembly and disassembly process, there is a risk of oil leakage. In this embodiment, the end face of the auxiliary cylinder 1 is provided with an end face sealing structure. The end face sealing structure is used to seal the end face of the internal expansion locking hydraulic cylinder. Specifically, it is designed as an end face sealing groove 16 and a sealing ring.

[0046] In other embodiments, other forms of sealing structures may also be used, such as sealing rings that completely fill the joint.

[0047] To ensure the accuracy and precision of oil pressure control, a hydraulic control unit is also included. This unit comprises a hydraulic pump 21, an oil suction port 22, a safety valve 23, an unloading valve 24, an oil output port 25, an accumulator 26, and a pressure gauge 27. The oil inlet of the hydraulic pump 21 is connected to the oil suction port 22, and the oil outlet of the hydraulic pump 21 is connected to the oil output port 25. The safety valve 23 is connected to the inlet and outlet of the hydraulic pump 21 to form a circuit for protecting the hydraulic pump 21. The unloading valve 24 is connected to the outlet of the hydraulic cylinder 21 to unload oil pressure, and its other end is connected to the oil tank. The accumulator 26 and the pressure gauge 27 are located at the oil output port 25 to observe the oil pressure. The oil output port provides hydraulic oil during the assembly and disassembly of the internal expansion locking hydraulic cylinder, primarily supplying high-pressure oil to the locking control port 52 of the internal expansion locking hydraulic cylinder to drive the locking body 54 to increase pressure and unlock the piston 11.

[0048] A method for assembling and disassembling an internally expanding locking hydraulic cylinder includes an assembly and disassembly device for the internally expanding locking hydraulic cylinder, and the assembly and disassembly are performed in the following manner: Since the assembly and disassembly process is the reverse of the operation procedure, this embodiment will take the process of installing piston 11 and piston rod 12 as an example for detailed explanation.

[0049] Part One: Disassemble the front cover 53 of the internal expansion locking hydraulic cylinder 5 to expose the cylinder body 51.

[0050] The piston 11 and piston rod 12 to be installed are pre-installed into the auxiliary cylinder 1 by conventional means. The piston rod 12 passes through the piston rod through hole 13. The piston left seal 55 and piston right seal 56 of the piston 11 are sealed with the inner wall of the auxiliary cylinder 1. The docking end of the auxiliary cylinder 1 is locked and sealed to the front end of the internal expansion locking hydraulic cylinder 5 by the end face locking sealing assembly 4. During the docking process, the piston 11 and piston rod 12 are connected with the locking control mechanism of the internal expansion locking hydraulic cylinder 5.

[0051] In this embodiment, the locking control mechanism of the internal expansion locking hydraulic cylinder 5 includes a locking control port 52, a guide rod 57, a guide rod seal 58, and a guide rod end face seal 59. The guide rod end face seal 59 is used for sealing between the locking control port 52 and the cylinder body 51, and the guide rod seal 58 is used for sealing between the guide rod 57 and the piston 11.

[0052] Then, the upper chamber inlet 60 of the internal expansion locking hydraulic cylinder 5 is sealed with a plug, and the lower chamber inlet 61 is connected to the hydraulic system.

[0053] Part Two: Since the piston 11 is located in the auxiliary cylinder 1 at this time, and its inner diameter is slightly larger, the piston 11 and the inner wall of the auxiliary cylinder 1 are in clearance fit without providing unlocking force, and can move freely. At the same time, since the clearance is controlled within the set range, the piston left seal 55 and piston right seal 56 can also provide a good sealing effect. Hydraulic oil is injected into the installation oil port 2 of the auxiliary cylinder 1, driving the piston 11 and piston rod 12 to move to the left and enter the internal expansion locking hydraulic cylinder 5. When the locking body 54 moves to the joint between the auxiliary cylinder 1 and the cylinder 51, the piston left seal 55 enters the internal expansion locking hydraulic cylinder 5. Due to the smaller inner diameter of the cylinder 51, it encounters greater frictional resistance. At this time, the hydraulic pump 21 is turned on to supply oil to the locking control port 52. The high-pressure oil enters the control chamber 62 where the locking body 54 is located. The cylinder 51 and the auxiliary cylinder 1 at the locking body 54 are both expanded. The locking body 54 and the inner wall of the cylinder 51 form a clearance fit. Driven by the hydraulic oil injected through the oil injection port 2, the piston 11 continues to move to the left until it is fully inserted into the internal expansion locking hydraulic cylinder 5.

[0054] During the above process, it is necessary to constantly monitor the pressure gauge reading. When the pressure gauge reading is too high, a certain amount of pressure is unloaded through the unloading valve. When the pressure gauge reading is too low, more hydraulic oil is added.

[0055] Part Three: Disassemble the auxiliary cylinder; Install the front cover of the internal expansion locking hydraulic cylinder into place.

[0056] The basic principle of disassembling the piston and piston rod is the same as the installation process, but the process is reversed.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A method for installing an internally expanding locking hydraulic cylinder using an assembly and disassembly device, characterized in that: The device includes an auxiliary cylinder, an oil inlet, a rod sealing structure, and an end face locking sealing assembly. One end of the auxiliary cylinder is the docking end of the internal expansion locking hydraulic cylinder, and the end face locking and sealing assembly is used to lock and seal the docking end of the auxiliary cylinder with the end of the internal expansion locking hydraulic cylinder. The other end of the auxiliary cylinder is provided with a piston rod passage hole, and the rod sealing structure is provided on the inner surface of the piston rod passage hole to form a movable sealing structure; The oil injection port is located on the side of the auxiliary cylinder and communicates with the inside of the auxiliary cylinder, and is used to inject hydraulic oil into the auxiliary cylinder. The inner diameter of the auxiliary cylinder is larger than the inner diameter of the internal expansion locking hydraulic cylinder that is adapted to it. The installation can be performed in the following manner: Part One: The piston and piston rod are pre-installed inside the auxiliary cylinder, and the mating end of the auxiliary cylinder is locked and sealed at the front end of the internal expansion locking hydraulic cylinder by the end face locking and sealing assembly. And make the piston and piston rod cooperate with the locking control mechanism of the internal expansion locking hydraulic cylinder; Part Two: Hydraulic oil is injected into the oil inlet of the auxiliary cylinder, driving the piston and piston rod to move inward into the hydraulic cylinder for locking. When the locking body in the piston moves to the splicing surface of the auxiliary cylinder and the internal expansion locking hydraulic cylinder, hydraulic oil is injected into the locking control port of the internal expansion locking hydraulic cylinder to unlock the piston; Continue injecting hydraulic oil into the installation port of the auxiliary cylinder to drive the piston and piston rod as a whole into the internal expansion locking hydraulic cylinder; Part Three: Disassemble the auxiliary cylinder and install the front cover of the internal expansion locking hydraulic cylinder into place.

2. The method for installing an internally expanding locking hydraulic cylinder using the assembly and disassembly device for an internally expanding locking hydraulic cylinder according to claim 1, characterized in that: The inner diameter of the auxiliary cylinder is matched with the piston of the internal expansion locking hydraulic cylinder to form a pressure-holding and sealing structure under a set pressure.

3. The method for installing an internally expanding locking hydraulic cylinder using an assembly and disassembly device according to claim 1 or 2, characterized in that: The inner diameter of the auxiliary cylinder is 0.25-0.35 mm larger than the inner diameter of the cylinder of the internal expansion locking hydraulic cylinder that is adapted to it.

4. The method for installing an internally expanding locking hydraulic cylinder using an assembly and disassembly device according to claim 1 or 2, characterized in that: The end face locking and sealing assembly includes a flange and connecting bolts disposed on the outside of the auxiliary cylinder barrel docking end. The connecting bolts cooperate with the flange to lock and fix the end of the internal expansion locking hydraulic cylinder.

5. The method for installing an internally expanding locking hydraulic cylinder using the assembly and disassembly device for an internally expanding locking hydraulic cylinder according to claim 4, characterized in that: The auxiliary cylinder barrel has an end face sealing structure on its docking end face, which is used to seal the end face of the internal expansion locking hydraulic cylinder.

6. The method for installing an internally expanding locking hydraulic cylinder using the assembly and disassembly device for an internally expanding locking hydraulic cylinder according to claim 3, characterized in that: The oil injection port is located in the area near the piston rod through hole.

7. The method for installing an internally expanding locking hydraulic cylinder using the assembly and disassembly device for an internally expanding locking hydraulic cylinder according to claim 4, characterized in that: The flange is connected and fixed to the auxiliary cylinder by thread, welding, or clamping.

8. The method for installing an internally expanding locking hydraulic cylinder using an assembly and disassembly device according to claim 1, 2, 5, or 6, characterized in that: It also includes a hydraulic control unit, which includes a hydraulic pump, an oil suction port, a safety valve, an unloading valve, an oil output port, an accumulator, and a pressure gauge. The oil inlet of the hydraulic pump is connected to the oil suction port, and the oil outlet of the hydraulic pump is connected to the oil output port. The safety valve is used to protect the hydraulic pump, the unloading valve is used to unload the oil pressure, and the accumulator and pressure gauge are located at the oil output port. The oil output port is used to provide hydraulic oil during the assembly and disassembly of the internal expansion locking hydraulic cylinder assembly and disassembly device.

9. A method for disassembling an internally expanding locking hydraulic cylinder using an assembly and disassembly device, characterized in that: The device includes an auxiliary cylinder, an oil inlet, a rod sealing structure, and an end face locking sealing assembly. One end of the auxiliary cylinder is the docking end of the internal expansion locking hydraulic cylinder, and the end face locking and sealing assembly is used to lock and seal the docking end of the auxiliary cylinder with the end of the internal expansion locking hydraulic cylinder. The other end of the auxiliary cylinder is provided with a piston rod passage hole, and the rod sealing structure is provided on the inner surface of the piston rod passage hole to form a movable sealing structure; The oil injection port is located on the side of the auxiliary cylinder and communicates with the inside of the auxiliary cylinder, and is used to inject hydraulic oil into the auxiliary cylinder. The inner diameter of the auxiliary cylinder is larger than the inner diameter of the matching internal expansion locking hydraulic cylinder, and it is disassembled in the following way: Part One: Disassemble the front cover of the internal expansion locking hydraulic cylinder and lock and seal the docking end of the auxiliary cylinder to the front end of the internal expansion locking hydraulic cylinder through the end face locking and sealing assembly. The piston rod of the internal expansion locking hydraulic cylinder passes through the piston rod through the hole in the auxiliary cylinder barrel; Part Two: Hydraulic oil is injected into the locking control port of the inward-expanding locking hydraulic cylinder to unlock the piston; Hydraulic oil is injected into the lower chamber of the inward-expanding locking hydraulic cylinder, driving the piston and piston rod to move as a whole toward the auxiliary cylinder until the piston and piston rod as a whole enter the auxiliary cylinder. When the locking body in the piston moves to the auxiliary cylinder, the hydraulic oil injected into the locking control port of the inward-expanding locking hydraulic cylinder is unloaded, and hydraulic oil continues to be injected into the lower chamber of the inward-expanding locking hydraulic cylinder until the piston and piston rod as a whole enter the required position of the auxiliary cylinder. Part Three: Disassemble the auxiliary cylinder; Remove the piston and piston rod from the auxiliary cylinder to complete the disassembly.

10. A device for assembling and disassembling an internally expanding locking hydraulic cylinder, characterized in that: This device is used in the method of installing an internally expanding locking hydraulic cylinder using the assembly and disassembly device for internally expanding locking hydraulic cylinders as described in claim 1, for the installation of internally expanding locking hydraulic cylinders.

11. A device for assembling and disassembling an internally expanding locking hydraulic cylinder, characterized in that: This device is used in the method of disassembling an internally expanding locking hydraulic cylinder using the assembly and disassembly device for an internally expanding locking hydraulic cylinder as described in claim 9, for the disassembly of the internally expanding locking hydraulic cylinder.

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