Double-hydraulic-cylinder type clamping device

Abstract

The double-hydraulic-cylinder type clamping device comprises a clamping head, a cylinder body is arranged below the clamping head, an upper end cover and a lower end cover are fixed to the upper end and the lower end of the cylinder body respectively, and the upper end cover is fixedly connected with the lower end of the clamping head; an upper clamping driving mechanism, a self-adaptive force balance mechanism, a lower clamping driving mechanism, an isolation plate and a self-locking mechanism are sequentially arranged in the cylinder body from top to bottom, an upper end cover of the upper clamping driving mechanism extends into the clamping head and is in sliding connection with the upper end cover, and the lower end of the lower clamping driving mechanism sequentially penetrates through the isolation plate and the self-locking mechanism; a hydraulic port E is formed in the corresponding side wall of the cylinder body between the self-locking mechanism and the isolation plate, a hydraulic port F is formed in the corresponding side wall of the cylinder body between the self-locking mechanism and the lower end cover, and a mounting guide rod M is fixedly mounted on the outer side wall of the lower end cover. The problem that in the prior art, a rigid connector of underwater equipment is affected by sea waves, water flow and a mud surface for a long time, so that connection is loosened, separation and sealing leakage are caused, and the operation process is interrupted is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil drilling and repairing equipment and relates to a double-liquid cylinder clamping device. Background Art

[0002] In the process of offshore oil and gas development, there are long-distance connections of underwater equipment such as underwater risers, watertight pipes, submarine umbilical cables, and production pipelines to establish closed channels for drilling, lifting and lowering operations, and oil and gas transportation. These underwater equipment are placed in the marine operating environment for a long time and are easily affected by external dynamic loads such as waves, water currents, and mud collapse, causing wear and fatigue damage to the rigid joints at the joints, resulting in loose connections, separation, and failure of sealing leakage, which interrupts the operation process. Once an abnormality occurs, it is usually necessary to conduct underwater inspection and maintenance, or recover the problematic equipment, and re-enter it after the repair is completed before continuing operations or production. The complex maintenance supporting equipment and personnel requirements, as well as the difficulty and long cycle of underwater maintenance operations, result in high maintenance operation costs. In summary, underwater equipment is prone to risks such as wear and breakage under the action of external dynamic loads, and after a failure occurs, the maintenance operation takes a long time and is risky, and the cost of deepwater operations is high. Therefore, there is an urgent need to develop a device that is easy to operate and can reduce the impact of external loads such as waves and currents on submarine umbilical cables, underwater risers, risers and production pipelines, so as to achieve long-term reliable connection and real-time connection status monitoring of underwater equipment, thereby improving its reliability and service life. Summary of the invention

[0003] The purpose of the present invention is to provide a double-cylinder clamping device, which solves the problem in the prior art that the rigid joints of underwater equipment are affected by waves, water currents and mud surfaces for a long time, resulting in loose connections, separation and seal leakage, thereby interrupting the operation process.

[0004] The technical solution adopted by the present invention is a double-cylinder clamping device, including a clamping head and a cylinder body arranged below the clamping head, wherein an upper end cover and a lower end cover are fixedly arranged at the upper and lower ends of the cylinder body respectively, and the upper end cover is fixedly connected to the lower end of the clamping head, and an upper clamping drive mechanism, an adaptive force balancing mechanism, a lower clamping drive mechanism, an isolation plate, and a self-locking mechanism are sequentially arranged in the cylinder body from top to bottom, the upper end of the upper clamping drive mechanism passes through the upper end cover to extend into the clamping head and is slidably connected to the upper end cover, and the lower end of the lower clamping drive mechanism passes through the isolation plate and the self-locking mechanism in sequence, a hydraulic port E is opened on the side wall of the cylinder body corresponding to the self-locking mechanism and the isolation plate, a hydraulic port F is opened on the side wall of the cylinder body corresponding to the self-locking mechanism and the lower end cover, and an installation guide rod M is fixedly installed on the outer wall of the lower end cover.

[0005] The present invention is also characterized in that

[0006] The clamping head is arranged as a clamping head with a "C"-shaped opening.

[0007] An end cover assembly hole is provided on the lower wall of the clamping head, a retaining nut slot is provided on the inner surface of the lower wall of the clamping head around the end cover assembly hole, an extension end is provided in the middle of the upper surface of the upper end cover, the extension end extends into the end cover assembly hole and into the "C"-shaped interior of the clamping head, the extension end of the upper end cover is connected to the retaining nut by a threaded connection, the retaining nut is clamped in the retaining nut slot, the clamping head and the upper end cover are fixed by the retaining nut being clamped in the retaining nut slot and the lower surface of the clamping head and the upper surface of the upper end cover being clamped.

[0008] The upper clamping drive mechanism includes an upper piston which is slidably connected to the inner wall of the cylinder body below the upper end cover in the cylinder body. A clamping rod is connected in the middle of the upper surface of the upper piston. The upper end of the clamping rod passes through the upper end cover and extends into the "C"-shaped interior of the clamping head. The clamping rod is slidably connected to the upper end cover. A pressure sensor is arranged on the top of the clamping rod. A cavity a is formed between the upper surface of the upper piston, the clamping rod and the lower surface of the upper end cover. A hydraulic port A is opened on the side wall of the cylinder body corresponding to the cavity a.

[0009] The lower clamping drive mechanism includes a lower piston slidably connected to the inner wall of the cylinder below the adaptive force balancing mechanism in the cylinder body, and a self-locking rod is fixedly connected to the center of the lower surface of the lower piston, and the lower end of the self-locking rod passes through the isolation plate and the self-locking mechanism in turn.

[0010] The adaptive force balancing mechanism is a plurality of groups of springs evenly arranged between the upper surface of the lower piston and the lower surface of the upper piston, and the two ends of the springs are respectively fixed on the upper surface of the lower piston and the lower surface of the upper piston.

[0011] The isolation plate is connected to the inner wall of the cylinder body by threaded connection, and a cavity b is formed between the upper surface of the isolation plate, the self-locking rod and the lower surface of the lower piston. A hydraulic port B is opened on the side wall of the cylinder body corresponding to the cavity b.

[0012] The self-locking mechanism includes multiple locking sliders, the outer contour of the locking slider is a conical surface, the inner side of the locking slider is a cylindrical surface, and the multiple locking sliders are spliced ​​into a complete hollow frustum body. The self-locking rod passes through the hollow part of the hollow frustum body. The outer diameter of the hollow frustum body gradually decreases from top to bottom. The inner wall of the corresponding hollow frustum body in the cylinder body is set as a conical surface matching the hollow frustum body. The upper and lower surfaces of the multiple locking sliders are respectively provided with an upper push plate and a lower push plate. The upper push plate and the lower push plate are adapted to the inner wall of the cylinder body and slide up and down on the inner wall of the cylinder body. The diameter of the upper push plate is equal to the maximum diameter of the hollow frustum body, and the diameter of the lower push plate is equal to the minimum diameter of the hollow frustum body. A T-slot distributed along the radial direction is provided at each locking slider position corresponding to the lower push plate, and a T-slot corresponding to the T-slot is provided on the upper and lower surfaces of each locking slider, and the T-slot slides radially along the upper push plate and the lower push plate in the T-slot; a cavity e is formed between the upper surface of the upper push plate, the self-locking rod, the inner wall of the cylinder body and the lower surface of the isolation plate, and a hydraulic port E is provided on the side wall of the cylinder body corresponding to the cavity e, and a cavity f is formed between the lower surface of the lower push plate, the self-locking rod, the inner wall of the cylinder body and the upper surface of the lower end cover, and a hydraulic port F is provided on the side wall of the cylinder body corresponding to the cavity f, and the cone angle of the locking slider, that is, the self-locking angle is γ, and the locking slider is made of deformable material.

[0013] A wear-resistant ring and a seal I are arranged between the upper end cover and the clamping rod from top to bottom, a seal II is arranged between the upper end cover and the inner wall of the cylinder body, a seal III is arranged between the upper piston and the inner wall of the cylinder body, a seal IV is arranged between the lower piston and the inner wall of the cylinder body, a seal V and a seal VI are arranged between the isolation plate and the self-locking rod and the inner wall of the cylinder body respectively, a seal VII and a seal VIII are arranged between the upper push plate and the self-locking rod and the inner wall of the cylinder body respectively, and a seal X and a seal IX are arranged between the lower push plate and the self-locking rod and the inner wall of the cylinder body respectively.

[0014] The beneficial effects of the present invention are:

[0015] The device is hydraulically driven, allowing remote and fully automatic operation. It is not limited by the operating water depth, solving the problem that deepwater and ultra-deepwater divers cannot operate, and reducing the cost and risk of underwater maintenance operations for underwater equipment. The adaptive force balancing mechanism of the clamping device can automatically adjust and absorb the force caused by changes in external loads, reducing the eccentric load and wear of underwater equipment caused by wind and waves, water flow and mud collapse, and improving the connection reliability and service life of underwater equipment. The device is a mechanical structure that can be used in harsh seabed environments and can be reused. By combining with a variety of cylinder sizes and the spring capacity of the adaptive force balancing mechanism, it meets the application requirements of the clamping force of specific underwater equipment, and has low manufacturing and use costs. The self-locking mechanism of the device, once the clamping operation is completed, does not require continuous energy supply and regular maintenance throughout the life cycle, and can provide a continuous and constant clamping force. The device has strong versatility and is suitable for a variety of underwater equipment such as underwater risers, risers, submarine umbilical cables, and production pipelines. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the double-liquid cylinder clamping device of the present invention;

[0017] Figure 2 It is a schematic diagram of the self-locking principle of the locking slide block in the double-liquid cylinder clamping device of the present invention;

[0018] Figure 3 It is a schematic diagram of the assembly structure of the locking slider, the upper push plate and the lower push plate in the double-cylinder clamping device of the present invention;

[0019] Figure 4 It is a schematic structural diagram of a locking slider and a T-shaped slider in a double-liquid cylinder clamping device of the present invention;

[0020] Figure 5 It is a schematic diagram of the installation of the double-cylinder clamping device of the present invention;

[0021] Figure 6 It is a process diagram of the loosening operation of the double-cylinder clamping device of the present invention.

[0022] In the figure, 1. lower end cover, 2. cylinder body, 3. locking slider, 3-1. T-slider, 4. self-locking rod, 5. isolation plate, 6. lower piston, 7. adaptive force balancing mechanism, 8. upper piston, 9. upper end cover, 10. clamping rod, 11. retaining nut, 12. clamping head, 13. sensor, 14. wear-resistant ring, 15. seal I, 16. seal II, 17. seal III, 16. seal IV, 19. seal V, 20. seal VI, 21. seal VII, 22. upper push plate, 22-1. T-slot, 23. seal VIII, 24. lower push plate, 25. seal IX, 26. seal X. DETAILED DESCRIPTION

[0023] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] Example 1

[0025] The double-cylinder clamping device of the present invention has a structure as follows Figure 1As shown, it includes a clamping head 12 and a cylinder body 2 arranged below the clamping head 12, an upper end cover 9 and a lower end cover 1 are fixedly arranged at the upper and lower ends of the cylinder body 2 respectively, the upper end cover 9 is fixedly connected to the lower end of the clamping head 12, and an upper clamping drive mechanism, an adaptive force balancing mechanism 7, a lower clamping drive mechanism, an isolation plate 5, and a self-locking mechanism are arranged in the cylinder body 2 from top to bottom. The upper end of the upper clamping drive mechanism passes through the upper end cover 9 and extends into the clamping head 12 and is slidably connected to the upper end cover 9, and the lower end of the lower clamping drive mechanism passes through the isolation plate 5 and the self-locking mechanism in sequence, a hydraulic port E is opened on the side wall of the cylinder body 2 corresponding to the self-locking mechanism and the isolation plate 5, a hydraulic port F is opened on the side wall of the cylinder body 2 corresponding to the self-locking mechanism and the lower end cover 1, and an installation guide rod M is fixedly installed on the outer wall of the lower end cover 1.

[0026] The clamping head 12 is configured as a clamping head with a “C”-shaped opening.

[0027] An end cover assembly hole is provided on the lower wall of the clamping head 12, and a retaining nut slot is provided on the inner surface of the lower wall of the clamping head 12 around the end cover assembly hole. An extended end is provided in the middle of the upper surface of the upper end cover 9, and the extended end extends into the end cover assembly hole and into the "C"-shaped interior of the clamping head 12. The extended end of the upper end cover 9 is connected to the retaining nut 11 by a threaded connection, and the retaining nut 11 is clamped in the retaining nut slot. The clamping head 12 and the upper end cover 9 are fixed by the retaining nut 11 being clamped in the retaining nut slot and the lower surface of the clamping head 12 and the upper surface of the upper end cover 9 being clamped.

[0028] The upper clamping drive mechanism includes an upper piston 8 which is slidably connected to the inner wall of the cylinder body 2 below the upper end cover 9 in the cylinder body 2. A clamping rod 10 is connected in the middle of the upper surface of the upper piston 8. The upper end of the clamping rod 10 passes through the upper end cover 9 and extends into the "C"-shaped interior of the clamping head 12. The clamping rod 10 is slidably connected to the upper end cover 9. A pressure sensor 13 is arranged on the top of the clamping rod 10. A cavity a is formed between the upper surface of the upper piston 8, the clamping rod 10 and the lower surface of the upper end cover 9. A hydraulic port A is opened on the side wall of the cylinder body 2 corresponding to the cavity a.

[0029] The lower clamping drive mechanism includes a lower piston 6 that is slidably connected to the inner wall of the cylinder body 2 below the adaptive force balancing mechanism 7 in the cylinder body 2. A self-locking rod 4 is fixedly connected to the center of the lower surface of the lower piston 6, and the lower end of the self-locking rod 4 passes through the isolation plate 5 and the self-locking mechanism in turn.

[0030] The adaptive force balancing mechanism 7 is a plurality of groups of springs evenly arranged between the upper surface of the lower piston 6 and the lower surface of the upper piston 8, and the two ends of the springs are fixed to the upper surface of the lower piston 6 and the lower surface of the upper piston 8 respectively.

[0031] The isolation plate 5 is connected to the inner wall of the cylinder body 2 by threaded connection, and a cavity b is formed between the upper surface of the isolation plate 5, the self-locking rod 4, and the lower surface of the lower piston 6. A hydraulic port B is opened on the side wall of the cylinder body 2 corresponding to the cavity b.

[0032] like Figure 2-4 As shown, the self-locking mechanism includes multiple locking sliders 3, the outer contour of the locking slider 3 is a conical surface, the inner side of the locking slider 3 is a cylindrical surface, and the multiple locking sliders 3 are spliced ​​into a complete hollow frustum body. The self-locking rod 4 passes through the hollow part of the hollow frustum body, and the outer diameter of the hollow frustum body gradually decreases from top to bottom. The inner wall of the hollow frustum body corresponding to the cylinder body 2 is set to a conical surface matching the hollow frustum body. The upper surfaces and lower surfaces of the multiple locking sliders 3 are respectively provided with an upper push plate 22 and a lower push plate 24. The upper push plate 22 and the lower push plate 24 are adapted to the inner wall of the cylinder body 2 and slide up and down on the inner wall of the cylinder body 2. The diameter of the upper push plate 22 is equal to the maximum diameter of the hollow frustum body, and the diameter of the lower push plate 24 is equal to the minimum diameter of the hollow frustum body. The upper push plate 22 and the lower push plate 24 are opposite to each other. A T-slot 22-1 distributed along its radial direction should be provided at the position of each locking slider 3, and a T-slot 3-1 corresponding to the T-slot 22-1 is provided on the upper and lower surfaces of each locking slider 3, and the T-slot 3-1 radially extends the upper push plate 22 and the lower push plate 24 in the T-slot 22-1. A cavity e is formed between the upper surface of the upper push plate 22, the self-locking rod 4, the inner wall of the cylinder body 2 and the lower surface of the isolation plate 5, and a hydraulic port E is provided on the side wall of the cylinder body 2 corresponding to the cavity e. A cavity f is formed between the lower surface of the lower push plate 24, the self-locking rod 4, the inner wall of the cylinder body 2 and the upper surface of the lower end cover 1, and a hydraulic port F is provided on the side wall of the cylinder body 2 corresponding to the cavity f. The cone angle of the locking slider 3, that is, the self-locking angle is γ, and the locking slider 3 is made of deformable material.

[0033] The working principle of the self-locking mechanism is as follows:

[0034] The locking slider 3 is a split rotating body structure, radially distributed around the self-locking rod 4, located between the upper push plate 22 and the lower push plate 24, with its outer contour being a cone and the inner contour being a cylinder; the cross-section of a single slider is a wedge-shaped structure, which can move axially under the action of external force, and the wedge angle γ is the self-locking angle; the upper and lower ends of the locking slider 3 are respectively inserted into the radial T-shaped grooves 22-1 in the upper push plate 22 and the lower push plate 24, and can move downward with the upper push plate 22, and can also move upward with the lower push plate 24; when the locking slider 3 moves upward, it moves radially away from the self-locking rod 4; when the locking slider 3 moves downward, the outer conical surface moves downward along the conical surface L of the cylinder body 2, and moves radially close to the self-locking rod 4.

[0035] A wear-resistant ring 14 and a seal Ⅰ15 are arranged between the upper end cover 9 and the clamping rod 10 from top to bottom, a seal Ⅱ16 is arranged between the upper end cover 9 and the inner wall of the cylinder body 2, a seal Ⅲ17 is arranged between the upper piston 8 and the inner wall of the cylinder body 2, a seal Ⅳ18 is arranged between the lower piston 6 and the inner wall of the cylinder body 2, a seal Ⅴ19 and a seal Ⅵ20 are arranged between the isolation plate 5 and the self-locking rod 4 and the inner wall of the cylinder body 2, respectively, a seal Ⅶ21 and a seal Ⅷ23 are arranged between the upper push plate 22 and the self-locking rod 4 and the inner wall of the cylinder body 2, respectively, and a seal Ⅹ26 and a seal Ⅸ25 are arranged between the lower push plate 24 and the self-locking rod 4 and the inner wall of the cylinder body 2.

[0036] The working principle of the double-cylinder clamping device of this embodiment is:

[0037] This device is used as a set, and the number of units used is not less than two. Figure 5 As shown, after two rigidly connected workpieces I and II are connected, the double-cylinder clamping device of the present invention is installed. Figure 3 A pair of double-cylinder clamping devices are used, and the two double-cylinder clamping devices are respectively placed on both sides of the connection between workpiece I and workpiece II, and the installation guide rod M is fixed on workpiece II to ensure that the connection between workpiece I and workpiece II is within the C-shaped of the clamping head 12 and between the upper end of the clamping rod 10 and the upper surface of the C-shaped inner part of the clamping head 12. Then the clamping operation is performed. The end of the clamping head 12 away from the retaining nut 11 is the upper working plane during the clamping action. The clamping operation is as follows:

[0038] Clamping operation:

[0039] The hydraulic ports A, E and F are depressurized, and pressure is applied to the cavity b through the hydraulic port B, so that the lower piston 6 drives the self-locking rod 4, the adaptive force balancing mechanism 7, the upper piston 8 and the clamping rod 10 to move to the upper limit position, clamping the connection between the workpiece I and the workpiece II. The clamping force reaches the preset value through the feedback information of the pressure sensor 13, and the clamping of the workpiece I and the workpiece II is completed;

[0040] Then, pressure is applied to the cavity e through the hydraulic port E, as Figure 1 As shown, the upper push plate 22 and the locking slide block 3 are pushed downward to the lower limit position; during the movement of the locking slide block 3 along the conical surface L of the cylinder body 2, the outer contour surface K of the self-locking rod 4 is tightly embraced to reach a locked state; the self-locking angle γ ensures that the locking slide block 3 always maintains the locked position when subjected to a downward axial external load; thus, the locking of the clamping position is completed;

[0041] Next, the hydraulic ports B and E are depressurized to disconnect the hydraulic source.

[0042] Eccentric load adjustment:

[0043] When workpiece I is subjected to a bending moment load, workpiece I and workpiece II tend to be separated on one side. At this time, the compressed spring force group of the adaptive force balancing mechanism 7 pushes the clamping rod 10 out, providing a continuous and stable clamping force, so that workpiece I and workpiece II are always in a reliably connected state.

[0044] Release operation:

[0045] Apply pressure to chamber b through hydraulic port B, and apply pressure to chamber f through hydraulic port F, such as Figure 6 As shown in the figure, it is a schematic diagram of pushing the push plate 24 and the locking slide block 3 upward, pushing the push plate 24 and the locking slide block 3 upward to the upper limit position; during the movement of the locking slide block 3 along the conical surface L of the cylinder body 2, the outer contour surface K of the self-locking rod 4 is released to reach the unlocking state. At this point, the unlocking of the clamping position is completed. The hydraulic port B is depressurized, and pressure is applied to the cavity a through the hydraulic port A, so that the upper piston 8 drives the clamping rod 10, the adaptive force balancing mechanism 7, the lower piston 6 and the self-locking rod 4 to move to the lower limit position, and the workpiece I and the workpiece II are released. The release state is monitored by the digital display of the pressure sensor 13. At this point, the release of the workpiece I and the workpiece II is completed. The hydraulic port A and the hydraulic port F are depressurized to disconnect the hydraulic source.

[0046] Example 2

[0047] On the basis of Example 1, the lower end cover 1 is a stepped structure, connected to the cylinder body 2 as a whole through threads, and the connection is welded.

[0048] Example 3

[0049] The upper end cover 9 is an L-shaped rotating body structure, which is connected to the cylinder body 2 as a whole through fastening screws at the bottom, has connecting threads at the top, and is equipped with a wear-resistant ring 14 on the inside.

[0050] The locking slider 3 is made of special material, which can be partially deformed under the action of external force, and generate friction between it and the self-locking rod 4;

[0051] A seal can be added between the lower end cover 1 and the self-locking rod 4 to form a closed cavity, and the closed cavity is connected to the closed cavity b to increase the clamping force of the clamping drive mechanism.

[0052] The double-cylinder clamping device of the present invention is used for monitoring the clamping and connection status of the joints of underwater equipment such as underwater risers, risers, submarine umbilical cables, and production pipelines after underwater installation and connection. The advantage is that the device is driven by hydraulic pressure, allows remote and fully automatic operation, is not limited by the operating water depth, does not require divers or underwater robots to operate, and reduces the cost and risk of underwater maintenance operations of underwater equipment. The clamping device can automatically adjust and absorb the force caused by changes in external loads, improve the connection reliability and service life of underwater equipment; the device is a mechanical structure, can be applied to harsh seabed environments, and can be reused, reducing manufacturing costs and use costs. The self-locking mechanism of the device, once the clamping operation is completed, does not require continuous energy supply throughout the life cycle, and can maintain a constant clamping force. The device has strong versatility and is suitable for a variety of underwater equipment such as underwater risers, risers, submarine umbilical cables, and production pipelines, and can meet the application requirements of the clamping force of specific underwater equipment by combining with a variety of cylinder sizes and energy storage component spring capacities.

[0053] The initial positioning and clamping of the double-cylinder clamping device of the present invention is achieved by hydraulically driving the clamping drive mechanism. When the clamping force is adjusted to a predetermined value, the self-locking mechanism is activated to maintain the clamping position of the clamping drive mechanism. When the load of the clamped system changes, the adaptive force balancing mechanism can respond in time, providing a constant clamping force during the entire use of the clamping device to reduce the impact of load changes caused by wind and waves, water flow, and mud collapse. The clamping drive mechanism and the self-locking mechanism of the clamping device are both hydraulically operated, and energy supply is required only during positioning and initial clamping. No energy supply and regular maintenance are required during use.

Claims

1. Double cylinder clamping device, characterized in that: The invention comprises a clamping head (12) and a cylinder body (2) arranged below the clamping head (12), wherein an upper end cover (9) and a lower end cover (1) are respectively fixedly arranged at the upper and lower ends of the cylinder body (2), wherein the upper end cover (9) is fixedly connected to the lower end of the clamping head (12), and an upper clamping drive mechanism, an adaptive force balancing mechanism (7), a lower clamping drive mechanism, an isolation plate (5), and a self-locking mechanism are arranged in sequence from top to bottom in the cylinder body (2), wherein the upper end of the upper clamping drive mechanism is The lower clamping drive mechanism passes through the upper end cover (9) and extends into the clamping head (12) and is slidably connected to the upper end cover (9). The lower end of the lower clamping drive mechanism passes through the isolation plate (5) and the self-locking mechanism in sequence. A hydraulic port E is provided on the side wall of the cylinder body (2) corresponding to the self-locking mechanism and the isolation plate (5). A hydraulic port F is provided on the side wall of the cylinder body (2) corresponding to the self-locking mechanism and the lower end cover (1). A mounting guide rod M is fixedly installed on the outer side wall of the lower end cover (1).

2. The double-cylinder clamping device according to claim 1, characterized in that: The clamping head (12) is configured as a clamping head with a "C"-shaped opening.

3. The double-cylinder clamping device according to claim 2, characterized in that: An end cover assembly hole is provided on the lower wall of the clamping head (12), and a retaining nut slot is provided on the inner surface of the lower wall of the clamping head (12) around the end cover assembly hole. A protruding end is provided in the middle of the upper surface of the upper end cover (9), and the protruding end extends into the end cover assembly hole and into the "C"-shaped interior of the clamping head (12). The protruding end of the upper end cover (9) is connected to a retaining nut (11) by a threaded connection, and the retaining nut (11) is clamped in the retaining nut slot. The clamping head (12) and the upper end cover (9) are fixed by the retaining nut (11) being clamped in the retaining nut slot and the lower surface of the clamping head (12) and the upper surface of the upper end cover (9) being clamped.

4. The double-cylinder clamping device according to claim 2, characterized in that: The upper clamping drive mechanism comprises an upper piston (8) which is slidably connected to the inner wall of the cylinder body (2) below the upper end cover (9) in the cylinder body (2); a clamping rod (10) is connected in the middle of the upper surface of the upper piston (8); the upper end of the clamping rod (10) passes through the upper end cover (9) and extends into the "C"-shaped interior of the clamping head (12); the clamping rod (10) is slidably connected to the upper end cover (9); a pressure sensor (13) is arranged on the top of the clamping rod (10); a cavity a is formed between the upper surface of the upper piston (8), the clamping rod (10) and the lower surface of the upper end cover (9); a hydraulic port A is opened on the side wall of the cylinder body (2) corresponding to the cavity a.

5. The double-cylinder clamping device according to claim 4, characterized in that: The lower clamping drive mechanism comprises a lower piston (6) which is slidably connected to the inner wall of the cylinder body (2) below the adaptive force balancing mechanism (7) in the cylinder body (2); a self-locking rod (4) is fixedly connected to the center of the lower surface of the lower piston (6); and the lower end of the self-locking rod (4) passes through the isolation plate (5) and the self-locking mechanism in sequence.

6. The double-cylinder clamping device according to claim 5, characterized in that: The adaptive force balancing mechanism (7) is a plurality of groups of springs evenly arranged between the upper surface of the lower piston (6) and the lower surface of the upper piston (8), and the two ends of the springs are respectively fixed to the upper surface of the lower piston (6) and the lower surface of the upper piston (8).

7. The double-cylinder clamping device according to claim 6, characterized in that: The isolation plate (5) is connected to the inner wall of the cylinder body (2) by means of a threaded connection, and a cavity b is formed between the upper surface of the isolation plate (5), the self-locking rod (4) and the lower surface of the lower piston (6), and a hydraulic port B is provided on the side wall of the cylinder body (2) corresponding to the cavity b.

8. The double-cylinder clamping device according to claim 7, characterized in that: The self-locking mechanism comprises a plurality of locking sliders (3), the outer contour of the locking sliders (3) being a conical surface, the inner side of the locking sliders (3) being a cylindrical surface, the plurality of locking sliders (3) being spliced ​​into a complete hollow truncated cone body, the self-locking rod (4) passing through the hollow part of the hollow truncated cone body, the outer diameter of the hollow truncated cone body gradually decreasing from top to bottom, the inner wall of the corresponding hollow truncated cone body in the cylinder body (2) being arranged as a conical surface matching the hollow truncated cone body, and the plurality of locking sliders (3) being spliced ​​into a complete hollow truncated cone body. The upper surface and lower surface of the locking slider (3) are respectively provided with an upper push plate (22) and a lower push plate (24), the upper push plate (22) and the lower push plate (24) are adapted to the inner wall of the cylinder body (2) and slide up and down on the inner wall of the cylinder body (2), the diameter of the upper push plate (22) is equal to the maximum diameter of the hollow truncated cone body, the diameter of the lower push plate (24) is equal to the minimum diameter of the hollow truncated cone body, and the upper push plate (22) and the lower push plate (24) correspond to Each locking slider (3) is provided with a T-slot (22-1) distributed along its radial direction, and the upper surface and lower surface of each locking slider (3) are provided with a T-slot (3-1) corresponding to the T-slot (22-1), and the T-slot (3-1) slides radially along the upper push plate (22) and the lower push plate (24) in the T-slot (22-1); the upper surface of the upper push plate (22), the self-locking rod (4), the inner wall of the cylinder body (2) and the like are connected to each other. A cavity e is formed between the lower surface of the push plate (24), the self-locking rod (4), the inner wall of the cylinder (2) and the upper surface of the lower end cover (1), and the hydraulic port F is formed on the side wall of the cylinder (2) corresponding to the cavity e. The conical angle of the locking slider (3), that is, the self-locking angle, is γ, and the locking slider (3) is made of a deformable material.

9. The double-cylinder clamping device according to claim 8, characterized in that: A wear-resistant ring (14) and a seal I (15) are arranged in sequence from top to bottom between the upper end cover (9) and the clamping rod (10); a seal II (16) is arranged between the upper end cover (9) and the inner wall of the cylinder body (2); a seal III (17) is arranged between the upper piston (8) and the inner wall of the cylinder body (2); a seal IV (18) is arranged between the lower piston (6) and the inner wall of the cylinder body (2); a seal V (19) and a seal VI (20) are arranged between the isolation plate (5) and the inner wall of the self-locking rod (4) and the cylinder body (2); a seal VII (21) and a seal VIII (23) are arranged between the upper push plate (22) and the inner wall of the self-locking rod (4) and the cylinder body (2); and a seal X (26) and a seal IX (25) are arranged between the lower push plate (24) and the inner wall of the self-locking rod (4) and the cylinder body (2).

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