Dual fluid cylinder clamp system and method of operation

Abstract

The application discloses a double-liquid-cylinder clamping system, which comprises a double-liquid-cylinder clamping device and a controller, wherein the double-liquid-cylinder clamping device comprises a clamping head and a clamping head hydraulic adjusting structure; a hydraulic input port of the clamping head hydraulic adjusting structure is connected with a hydraulic pump through a hydraulic delivery pipe; an electric control valve is arranged on the hydraulic delivery pipe; the hydraulic pump and the electric control valve are respectively connected with the controller through wires; the upper end of the clamping head hydraulic adjusting structure extends into the clamping head and forms two clamping working surfaces with the inner upper surface of the clamping head; the upper end of the clamping head hydraulic adjusting structure is provided with a pressure sensor; and the pressure sensor is connected with the controller through wires. The application solves the problem that the rigid joint of the underwater equipment is affected by sea waves, water flow and mud surface for a long time in the prior art, which leads to loose connection, separation and sealing leakage and interruption of the operation process. The application further discloses a working method of the double-liquid-cylinder clamping system.

Description

Technical Field

[0001] This invention belongs to the technical field of offshore oil and gas drilling and production equipment, and relates to a dual-cylinder clamping system. This invention also relates to the working method of the above-mentioned dual-cylinder clamping system. Background Technology

[0002] In offshore oil and gas development, long-distance connections of underwater equipment such as risers, subsea umbilical cables, and production pipelines are necessary to establish closed channels for drilling, tripping operations, and oil and gas transportation. These underwater devices are exposed to the marine environment for extended periods, making them susceptible to external dynamic loads such as waves, currents, and mudslides. This can cause wear and fatigue damage to rigid joints, leading to loosening, separation, and leaks, thus interrupting operations. Once an anomaly occurs, underwater inspection and repair are typically required, or the faulty equipment must be retrieved and repaired before being re-entered to resume operations or production. The complex maintenance equipment and personnel requirements, coupled with the difficulty and lengthy nature of underwater maintenance operations, result in high maintenance costs. In summary, underwater equipment is prone to wear and breakage due to external dynamic loads, and repairs after malfunctions are time-consuming, risky, and costly in deep-water operations. 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 enable underwater equipment to maintain a reliable connection for a long time and monitor the connection status in real time, thereby improving its reliability and service life. Summary of the Invention

[0003] The purpose of this invention is to provide a dual-cylinder clamping system that solves the problem in the prior art where the rigid joints of underwater equipment are subject to long-term effects from waves, water flow, and mud, leading to loosening, separation, and sealing leaks that interrupt the operation.

[0004] Another objective of this invention is to provide a method for operating a dual-cylinder clamping system.

[0005] The technical solution adopted in this invention is a dual-cylinder clamping system, including a dual-cylinder clamping device and a controller. The dual-cylinder clamping device includes a clamping head and a clamping head hydraulic adjustment structure. The hydraulic input port of the clamping head hydraulic adjustment structure is connected to a hydraulic pump through a hydraulic delivery pipe. An electric control valve is installed on the hydraulic delivery pipe. The hydraulic pump and the electric control valve are respectively connected to the controller through wires. The upper end of the clamping head hydraulic adjustment structure extends into the clamping head and forms two clamping working surfaces with the inner upper surface of the clamping head. A pressure sensor is installed at the upper end of the clamping head hydraulic adjustment structure, and the pressure sensor is connected to the controller through wires.

[0006] The invention is further characterized in that,

[0007] The hydraulic adjustment structure of the clamping head includes a cylinder body located below the clamping head. An upper end cover and a lower end cover are fixedly mounted at the upper and lower ends of the cylinder body, respectively. The upper end cover is fixedly connected to the lower end of the clamping head. From top to bottom, the cylinder body contains an upper clamping drive mechanism, an adaptive force balancing mechanism, a lower clamping drive mechanism, an isolation plate, and a self-locking mechanism. The upper end of the upper clamping drive mechanism extends through the upper end cover into the clamping head and is slidably connected to the upper end cover. 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 cylinder body sidewall corresponding to the self-locking mechanism and the isolation plate. A hydraulic port F is opened on the cylinder body sidewall corresponding to the self-locking mechanism and the lower end cover. A mounting guide rod M is fixedly installed on the outer sidewall of the lower end cover. Hydraulic ports F and E are connected to a hydraulic pump via hydraulic delivery pipes. Electrically controlled valves f and e are respectively installed on the hydraulic delivery pipes corresponding to hydraulic ports F and E. Electrically controlled valves f and e are respectively connected to the controller via wires. A cavity b is formed between the lower clamping drive mechanism, the isolation plate, and the inner wall of the cylinder. A hydraulic port B is opened on the side wall of the cylinder corresponding to cavity b. Hydraulic port B is connected to the hydraulic pump via a hydraulic delivery pipe. Electrically controlled valve b is installed on the hydraulic delivery pipe corresponding to hydraulic port B. Electrically controlled valve b is connected to the controller via wires. Position sensors a and b are respectively installed at the upper and lower limit positions of the self-locking mechanism inside the cylinder. Position sensors a and b are connected to a data acquisition device via wires. The data acquisition device is connected to the controller via wires. A temperature sensor is installed on the outer wall of the cylinder. The temperature sensor is connected to the data acquisition device via wires.

[0008] The clamping head is designed with a "C"-shaped opening. An end cap assembly hole is provided on the lower wall of the clamping head. A retaining nut groove is provided on the inner surface of the lower wall of the clamping head around the end cap assembly hole. An extension end is provided in the middle of the upper surface of the upper end cap. The extension end extends into the end cap assembly hole and into the "C"-shaped interior of the clamping head. A retaining nut is connected to the extension end of the upper end cap by a threaded connection. The retaining nut is locked in the retaining nut groove. The clamping head and the upper end cap are fixed by the retaining nut being locked in the retaining nut groove and by the locking of the lower surface of the clamping head and the upper surface of the upper end cap.

[0009] The upper clamping drive mechanism includes an upper piston that is slidably connected to the inner wall of the cylinder below the upper end cover. A clamping rod is connected to 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 installed at 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 corresponding to cavity a. The hydraulic port A is connected to a hydraulic pump through a hydraulic delivery pipe. An electric control valve a is installed on the hydraulic delivery pipe corresponding to hydraulic port A. The electric control valve a is connected to a controller through a wire. A position sensor c is installed in cavity a at the upper limit position corresponding to the upper piston. The position sensor c is connected to a data acquisition device through a wire.

[0010] The lower clamping drive mechanism includes a lower piston that is slidably connected to the inner wall of the cylinder below the adaptive force balancing mechanism inside the cylinder. 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 sequence.

[0011] The adaptive force balancing mechanism consists of multiple sets of springs evenly arranged between the upper surface of the lower piston and the lower surface of the upper piston. The two ends of the springs are fixed to the upper surface of the lower piston and the lower surface of the upper piston, respectively. The isolation plate is connected to the inner wall of the cylinder by a threaded connection. 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 position sensor d is set in the cavity b at the lower limit position of the lower piston. The position sensor d is connected to the data acquisition device through a wire.

[0012] The self-locking mechanism includes multiple locking sliders. The outer contour of each locking slider is a conical surface, and the inner side is a cylindrical surface. These sliders are assembled to form a complete hollow frustum. The self-locking rod passes through the hollow part of the frustum. The outer diameter of the frustum gradually decreases from top to bottom. The inner wall of the cylinder is set with a conical surface that mates with the frustum. The upper and lower surfaces of the locking sliders are respectively provided with an upper push plate and a lower push plate. The upper and lower push plates adapt to the inner wall of the cylinder and slide up and down within it. The upper and lower push plates are provided with a groove at each locking slider position. Its radially distributed T-slots, each locking slider has a T-slot corresponding to the T-slot on its upper and lower surfaces, the T-slot slides radially within the T-slot along the upper and lower push plates; cavity e is formed between the upper surface of the upper push plate, the self-locking rod, the inner wall of the cylinder and the lower surface of the isolation plate, and hydraulic port E is set on the cylinder side wall corresponding to cavity e; cavity f is formed between the lower surface of the lower push plate, the self-locking rod, the inner wall of the cylinder and the upper surface of the lower end cover, and hydraulic port F is set on the cylinder side wall corresponding to cavity f; the included angle of the conical surface of the locking slider, that is, the self-locking angle, is γ; the locking slider is made of deformable material.

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

[0014] Another technical solution adopted in this invention is to use the above-mentioned dual-cylinder clamping system, which specifically includes clamping operation, releasing operation and external load balancing, wherein the clamping operation includes clamping operation and locking operation, and the releasing operation includes unlocking operation and releasing operation.

[0015] After workpiece I and workpiece II are connected, at least two double-cylinder clamping devices are placed next to the connection point of workpiece I and workpiece II. The mounting guide rod M is fixed on workpiece II to ensure that the connection point of workpiece I and workpiece II is between the upper end of the clamping rod and the upper surface of the inner C-shape of the clamping head. Then the clamping operation is performed. The end of the clamping head away from the fixing nut is the upper working plane during the clamping action.

[0016] The clamping operation is as follows:

[0017] Clamping: The controller controls the hydraulic pump and the electric valve b to open, and the hydraulic oil is input into the cavity b through the hydraulic port B to apply pressure to the cavity b. This causes the lower piston to drive the self-locking rod, the adaptive force balancing mechanism, the upper piston and the clamping rod to move upward. The upper end of the clamping rod and the upper surface inside the clamping head clamp the connection between workpiece I and workpiece II. During the process, the pressure sensor feeds back the pressure information to the controller in real time. When the feedback pressure information reaches the preset value of the required clamping force and triggers the position sensor d, the controller controls the hydraulic pump to stop inputting hydraulic oil. At this point, the clamping of workpiece I and workpiece II is completed.

[0018] Lock:

[0019] Maintaining pressure within cavity b, the controller opens the hydraulic pump and the corresponding electronically controlled valve e at hydraulic port E, supplying hydraulic oil to cavity e to apply pressure. Under the action of the hydraulic oil, the locking slider moves downward to its lower limit position and triggers position sensor b. As the locking slider moves downward along the cylinder cone surface L, it grips the outer contour surface K of the self-locking rod, achieving a locked state. The wedge-shaped surface of the locking slider has a self-locking function, ensuring that the self-locking rod remains locked under downward axial external loads, thus completing the locking of the clamping position. The controller then controls the hydraulic pump to release pressure from cavities e and b, disconnecting the hydraulic source and closing the hydraulic pump, electronically controlled valve e, and electronically controlled valve b. The clamped product remains in a clamped and locked state.

[0020] When inspecting or retrieving clamped products, the locking lever must be unlocked and the clamping lever retracted to release workpiece I and workpiece II. The specific release operation is as follows:

[0021] Unlock:

[0022] The controller controls the hydraulic pump and the opening of the solenoid valve b. The hydraulic pump injects hydraulic oil into cavity b, applying pressure to the cavity b to the pressure corresponding to the clamping operation. The controller closes the solenoid valve b and simultaneously controls the opening of the solenoid valve f, injecting hydraulic oil into cavity f to apply pressure to cavity f to the preset pressure. After the pressure is maintained, the solenoid valve f is closed. When hydraulic oil is injected into cavity f, the locking slider gradually moves upward, moving radially away from the self-locking rod to the upper limit position and triggering the position sensor a in the cylinder. The outer contour surface K of the self-locking rod is released, and the self-locking rod is in the unlocked state. The controller controls the opening of the solenoid valve b, using the hydraulic pump to slowly reduce the pressure in cavity b. The external load of the adaptive force balancing mechanism is released, and it expands until the clamping force fed back by the pressure sensor on the end face of the clamping rod is zero, thus completely depressurizing cavity b. The solenoid valve b is then closed, thus completing the unlocking of the clamping position.

[0023] Loosening:

[0024] The controller opens the solenoid valve f, and the hydraulic pump depressurizes the cavity f. After completion, the controller closes the solenoid valve f and opens the solenoid valve a, supplying hydraulic oil to the cavity a and applying pressure to it. This causes the upper piston to move the clamping rod, the adaptive force balancing mechanism, the lower piston, and the self-locking rod to the lower limit position, triggering the position sensor d inside the cylinder. This completes the release of workpiece I and workpiece II. Then, the controller depressurizes the cavity a by controlling the hydraulic pump. After completion, the hydraulic pump and solenoid valve a are closed to disconnect the hydraulic power source.

[0025] External load balancing specifically refers to:

[0026] When workpiece I is subjected to bending moment load, workpiece I tends to separate from workpiece II on one side. At this time, the spring force group of the compressed adaptive force balancing mechanism pushes out the clamping rod, providing a continuous and stable clamping force, so that workpiece I and workpiece II are always in a reliable connection state.

[0027] The beneficial effects of this invention are:

[0028] This invention, driven by hydraulics, allows for remote and fully automatic operation, unrestricted by water depth, solving the problem that deep-water and ultra-deep-water divers cannot operate in these conditions. It also reduces the cost and risk of underwater equipment maintenance, and its remote data acquisition and monitoring capabilities enhance the automatic control capabilities of underwater equipment.

[0029] The adaptive force balancing mechanism of the present invention can automatically adjust and absorb the force caused by changes in external load, reduce the off-center load and wear of underwater equipment caused by wind, waves, water flow and mud surface collapse, and improve the connection reliability and service life of underwater equipment.

[0030] The clamping device of the present invention is a mechanical structure that is suitable for harsh seabed environments and is reusable. By combining it with various cylinder sizes and adaptive force balancing mechanism spring capacities, it can meet the application requirements of clamping force for specific underwater equipment, and has low manufacturing and operating costs.

[0031] The self-locking mechanism of this invention provides a continuous and constant clamping force once the clamping operation is completed, without requiring continuous energy supply or regular maintenance throughout its entire lifespan. This device is highly versatile and suitable for various underwater equipment such as underwater risers, risers, submarine umbilical cables, and production pipelines. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the dual-cylinder clamping system of the present invention;

[0033] Figure 2 This is a schematic diagram of the structure of the dual-cylinder clamping device in the dual-cylinder clamping system of the present invention;

[0034] Figure 3 This is a schematic diagram of the self-locking principle of the locking slider in the dual-cylinder clamping device of the present invention;

[0035] Figure 4 This is a schematic diagram of the assembly structure of the locking slider, the upper push plate, and the lower push plate in the dual-cylinder clamping device of the present invention.

[0036] Figure 5 This is a schematic diagram of the locking slider and T-shaped slider in the dual-cylinder clamping device of the present invention;

[0037] Figure 6 This is a process diagram of the release operation of the dual-cylinder clamping device of the present invention;

[0038] Figure 7 This is the circuit connection diagram of the present invention.

[0039] In the diagram, 1. Lower end cover, 2. Cylinder body, 3. Locking slider, 3-1. T-shaped 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. Fixing nut, 12. Clamping head, 13. Pressure sensor, 14. Wear-resistant ring, 15. Seal I, 16. Seal II, 17. Seal III, 18. Seal IV, 19. Seal V, 20. Seal VI, 21. Seal VII, 2 2. Upper push plate, 22-1. T-slot, 23. Seal VIII, 24. Lower push plate, 25. Seal IX, 26. Seal X, 27. Controller, 28. Hydraulic pump, 29-1. Position sensor a, 29-2. Position sensor b, 29-3. Position sensor c, 29-4. Position sensor d, 30. Temperature sensor, 31-1. Solenoid valve f, 31-2. Solenoid valve e, 31-3. Solenoid valve b, 31-4. Solenoid valve a, 32. Data collector. Detailed Implementation

[0040] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0041] Example 1

[0042] The present invention provides a dual-cylinder clamping system, such as... Figure 1 and Figure 7 As shown, it includes a dual-cylinder clamping device and a controller 27, such as Figure 2 As shown, the dual-cylinder clamping device includes a clamping head 12 and a clamping head hydraulic adjustment structure. The hydraulic input port of the clamping head hydraulic adjustment structure is connected to a hydraulic pump 28 through a hydraulic delivery pipe. An electric control valve is installed on the hydraulic delivery pipe. The hydraulic pump 28 and the electric control valve are respectively connected to a controller 27 through wires. The upper end of the clamping head hydraulic adjustment structure extends into the clamping head 12 and forms two clamping working surfaces with the inner upper surface of the clamping head 12. A pressure sensor 13 is installed at the upper end of the clamping head hydraulic adjustment structure. The pressure sensor 13 is connected to the controller 27 through wires.

[0043] The hydraulic adjustment structure of the clamping head includes a cylinder 2 located below the clamping head 12. An upper end cover 9 and a lower end cover 1 are fixedly mounted at the upper and lower ends of the cylinder 2, respectively. The upper end cover 9 is fixedly connected to the lower end of the clamping head 12. Inside the cylinder 2, from top to bottom, are arranged 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. The upper end of the upper clamping drive mechanism extends through the upper end cover 9 into the clamping head 12 and is slidably connected to the upper end cover 9. The lower clamping drive mechanism… The lower end 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 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 2 corresponding to the self-locking mechanism and the lower end cover 1. An installation guide rod M is fixedly installed on the outer wall of the lower end cover 1. The hydraulic ports F and E are respectively connected to the hydraulic pump 28 through hydraulic delivery pipes. An electric control valve f31-1 and an electric control valve e31-2 are respectively installed on the hydraulic delivery pipes corresponding to the hydraulic ports F and E. Electrically controlled valves f31-1 and e31-2 are connected to controller 27 via wires. A cavity b is formed between the lower clamping drive mechanism, the isolation plate 5, and the inner wall of the cylinder 2. A hydraulic port B is provided on the side wall of the cylinder 2 corresponding to cavity b. The hydraulic port B is connected to the hydraulic pump 28 via a hydraulic delivery pipe. An electrically controlled valve b31-3 is installed on the hydraulic delivery pipe corresponding to hydraulic port B. The electrically controlled valve b31-3 is connected to controller 27 via wires. Position sensors a29-1 and b29-2 are respectively installed at the upper and lower limit positions of the self-locking mechanism inside the cylinder 2. Position sensors a29-1 and b29-2 are connected to a data acquisition device 32 via wires. The data acquisition device 32 is connected to controller 27 via wires. A temperature sensor 30 is installed on the outer wall of the cylinder 2. The temperature sensor 30 is connected to the data acquisition device 32 via wires to collect temperature information of the environment in which the clamping device is installed. The collected information is transmitted to the controller via wires.

[0044] The clamping head 12 is configured as a "C"-shaped opening clamping head. An end cap assembly hole is provided on the lower wall of the clamping head 12. A retaining nut groove is provided around the end cap assembly hole on the inner surface of the lower wall of the clamping head 12. An extension end is provided in the middle of the upper surface of the upper end cap 9. The extension end extends into the end cap assembly hole and into the "C"-shaped interior of the clamping head 12. A retaining nut 11 is connected to the extension end of the upper end cap 9 by means of a threaded connection. The retaining nut 11 is locked in the retaining nut groove. The clamping head 12 and the upper end cap 9 are fixed by the retaining nut 11 being locked in the retaining nut groove and the clamping head 12 being locked in place by the lower surface of the clamping head 12 and the upper surface of the upper end cap 9.

[0045] The upper clamping drive mechanism includes an upper piston 8 that is slidably connected to the inner wall of the cylinder 2 below the upper end cover 9 inside the cylinder 2. A clamping rod 10 is connected to 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 provided at 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 provided on the side wall of the cylinder 2 corresponding to the cavity a. The hydraulic port A is connected to the hydraulic pump 28 through a hydraulic transmission pipe. An electric control valve a31-4 is provided on the hydraulic transmission pipe corresponding to the hydraulic port A. The electric control valve a31-4 is connected to the controller 27 through a wire. A position sensor c29-3 is provided in the cavity a at the upper limit position corresponding to the upper piston 8. The position sensor c29-3 is connected to the data acquisition device 32 through a wire.

[0046] The lower clamping drive mechanism includes a lower piston 6 that is slidably connected to the inner wall of the cylinder 2 below the adaptive force balancing mechanism 7 inside the cylinder 2. A self-locking rod 4 is fixedly connected to the center of the lower surface of the lower piston 6. The lower end of the self-locking rod 4 passes through the isolation plate 5 and the self-locking mechanism in sequence.

[0047] The adaptive force balancing mechanism 7 consists of multiple sets of springs evenly arranged between the upper surface of the lower piston 6 and the lower surface of the upper piston 8. 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. The isolation plate 5 is connected to the inner wall of the cylinder 2 by a threaded connection. 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 position sensor d29-4 is set in the cavity b at the lower limit position of the lower piston 6. The position sensor d29-4 is connected to the data acquisition device 32 by a wire.

[0048] like Figure 3-5As shown, the self-locking mechanism includes multiple locking sliders 3. The outer contour of each locking slider 3 is a conical surface, and the inner side is a cylindrical surface. The multiple locking sliders 3 are assembled into a complete hollow frustum. The self-locking rod 4 passes through the hollow part of the hollow frustum. The outer diameter of the hollow frustum gradually decreases from top to bottom. The inner wall of the cylinder 2 is set with a conical surface that matches the hollow frustum. The upper 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 2 and slide up and down on the inner wall of the cylinder 2. The upper push plate 22 and the lower push plate 24 are provided with radially spaced features corresponding to the position of each locking slider 3. The T-slots 22-1 are distributed, and each locking slider 3 has a T-slot corresponding to the T-slot 22-1 on its upper and lower surfaces. The T-slot slides radially within the T-slot 22-1 along the upper push plate 22 and the lower push plate 24. 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 2, and the lower surface of the isolation plate 5. The hydraulic port E is located on the side wall of the cylinder 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 2, and the upper surface of the lower end cover 1. The hydraulic port F is located on the side wall of the cylinder 2 corresponding to the cavity f. The cone angle of the locking slider 3, which is the self-locking angle, is γ. The locking slider 3 is made of deformable material.

[0049] The working principle of the self-locking mechanism is as follows:

[0050] The locking slider 3 is a split rotary structure, radially distributed around the self-locking rod 4, located between the upper push plate 22 and the lower push plate 24. Its outer contour is a conical surface, and its inner side is a cylindrical surface. The cross-section of a single slider is a wedge-shaped structure, which can move axially under the action of external force. 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. It can move downward with the upper push plate 22 and 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 closer to the self-locking rod 4.

[0051] A wear-resistant ring 14 and a seal I 15 are arranged sequentially 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 2. A seal III 17 is arranged between the upper piston 8 and the inner wall of the cylinder 2. A seal IV 18 is arranged between the lower piston 6 and the inner wall of the cylinder 2. A seal V 19 and a seal VI 20 are arranged between the isolation plate 5, the self-locking rod 4, and the inner wall of the cylinder 2, respectively. A seal VII 21 and a seal VIII 23 are arranged between the upper push plate 22, the self-locking rod 4, and the inner wall of the cylinder 2, respectively. A seal X 26 and a seal IX 25 are arranged between the lower push plate 24, the self-locking rod 4, and the inner wall of the cylinder 2, respectively.

[0052] The upper end cover 9 of this invention has an L-shaped rotating structure. It is connected to the cylinder 2 at the bottom by fastening screws and has connecting threads at the top. A wear-resistant ring 14 is installed on the inner side. The locking slider 3 is made of a special material that can undergo local deformation under external force, generating friction between it and the self-locking rod 4. A seal can be added between the lower end cover 1 and the self-locking rod 4 to form a closed cavity, which is connected to the closed cavity b to increase the clamping force of the clamping drive mechanism.

[0053] Example 2

[0054] The working method of the dual-cylinder clamping system of the present invention, using the dual-cylinder clamping system of Example 1, specifically includes clamping operation, releasing operation, and external load balancing. The clamping operation includes clamping and locking operations, and the releasing operation includes unlocking and releasing operations.

[0055] like Figure 6 As shown, after workpiece I and workpiece II are connected, at least two double-cylinder clamping devices are placed next to the connection point of workpiece I and workpiece II. The mounting guide rod M is fixed on workpiece II to ensure that the connection point of workpiece I and workpiece II is between the upper end of the clamping rod 10 and the upper surface of the inner C-shape of the clamping head 12. Then the clamping operation is performed. The end of the clamping head 12 away from the fixing nut 11 is the upper working plane during the clamping action.

[0056] The clamping operation is as follows:

[0057] Clamping: The controller 27 controls the hydraulic pump 28 and the solenoid valve b31-3 to open, and input hydraulic oil into the cavity b through the hydraulic port B to apply pressure to the cavity b. This causes the lower piston 6 to drive the self-locking rod 4, the adaptive force balancing mechanism 7, the upper piston 8 and the clamping rod 10 to move upward. The upper end of the clamping rod 10 and the upper surface inside the clamping head 12 clamp the connection between workpiece I and workpiece II. During the process, the pressure sensor 13 feeds back the pressure information to the controller 27 in real time. When the feedback pressure information reaches the preset value of the required clamping force and triggers the position sensor d29-4, the controller 27 controls the hydraulic pump 28 to stop inputting hydraulic oil. Thus, the clamping of workpiece I and workpiece II is completed.

[0058] Lock:

[0059] Maintaining the pressure inside cavity b, the controller 27 controls the hydraulic pump 28 and the solenoid valve e31-2 to open, supplying hydraulic oil to cavity e to apply pressure. Under the action of the hydraulic oil, the locking slider 3 moves downward to the lower limit position and triggers the position sensor b29-2. As the locking slider 3 moves downward along the cone surface L of the cylinder 2, it grips the outer contour surface K of the self-locking rod 4, achieving a locked state. The wedge-shaped surface of the locking slider 3 has a self-locking function, ensuring that the self-locking rod 4 always remains in the locked position when subjected to a downward axial external load, thus completing the locking of the clamping position. The controller 27 controls the hydraulic pump 28 to release pressure to cavity e and cavity b, disconnecting the hydraulic source and closing the hydraulic pump 28, solenoid valve e, and solenoid valve b. The clamped product always remains in a clamped and locked state.

[0060] When inspecting or retrieving clamped products, the locking rod must be unlocked and the clamping rod 10 retracted to release workpiece I and workpiece II. The specific release operation is as follows:

[0061] Unlock:

[0062] The controller 27 controls the hydraulic pump 28 and the solenoid valve b to open. The hydraulic pump 28 injects hydraulic oil into the cavity b, applying pressure to the cavity b to the pressure corresponding to the clamping operation. The solenoid valve b is closed, and the controller 27 controls the solenoid valve f to open, injecting hydraulic oil into the cavity f to apply pressure to the cavity f to the preset pressure. After that, the solenoid valve f is closed to maintain this pressure. When hydraulic oil is injected into the cavity f, the locking slider 3 gradually moves upward, moving radially away from the self-locking rod 4 to the upper limit position, and triggers the position sensor a29-1 in the cylinder 2. The outer contour surface K of the self-locking rod 4 is released, and the self-locking rod 4 is in the unlocked state. The controller 27 controls the solenoid valve b to open, and the hydraulic pump 28 slowly reduces the pressure in the cavity b. The adaptive force balancing mechanism 7 is released from the external load and expands until the clamping force fed back by the pressure sensor 13 on the end face of the clamping rod 10 is zero, thus completely depressurizing the cavity b. The solenoid valve b is then closed, thus completing the unlocking of the clamping position. Release:

[0063] The controller 27 controls the opening of the solenoid valve f, and the hydraulic pump 28 is used to depressurize the cavity f. After completion, the controller 27 controls the closing of the solenoid valve f and the opening of the solenoid valve a, which supplies hydraulic oil to the cavity a and applies pressure to the cavity a. This causes the upper piston 8 to drive 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 trigger the position sensor d29-4 in the cylinder 2. This completes the release of workpiece I and workpiece II. Then, the controller 27 controls the hydraulic pump 28 to depressurize the cavity a. After completion, the hydraulic pump 28 and the solenoid valve a are turned off to disconnect the hydraulic power source.

[0064] The release operation process of the present invention avoids the impact on the device caused by the sudden loss of external force on the clamping rod 10 and the self-locking rod 4, as well as the impact on the connected joints, threads, fasteners, etc. after the clamping force of the clamped product suddenly disappears.

[0065] External load balancing specifically refers to:

[0066] When workpiece I is subjected to bending moment load, workpiece I tends to separate from workpiece II on one side. At this time, the spring force group of the compressed adaptive force balancing mechanism 7 pushes out the clamping rod 10, providing a continuous and stable clamping force, so that workpiece I and workpiece II are always in a reliable connection state.

[0067] Example 3

[0068] Based on Examples 1 and 2, such as Figure 1 As shown, after workpiece I and workpiece II are connected, two double-cylinder clamping devices are placed on the F and E sides of the connection point between workpiece I and workpiece II, respectively.

[0069] Operating Condition Description: Under normal operating conditions, after underwater risers, risers, submarine umbilical cables, production pipelines, and other products are clamped by this device, the clamping rod 10 is in the extended working state during use, the self-locking rod 4 is locked, and the data deviations of various sensors in all dual-cylinder clamping devices in the clamping system are within the normal operating range. When the clamped products are subjected to external loads of multiple angles and directions, such as bending moments, torques, and tensile forces, caused by factors such as wind, waves, water flow, and mud surface collapse, this device can automatically activate the adaptive force balancing mechanism 7 to adjust the external loads.

[0070] When the clamped products are subjected to an external load of overturning force, workpiece I and workpiece II tend to separate on side F, while workpiece I and workpiece II tend to move closer on side E. At this time, under the influence of the external load, the clamping rod 10 on side E tends to move upward, and the spring group in the adaptive force balancing mechanism 7 expands, causing the clamping rod 10 to push upward, balancing part of the squeezing force on workpiece I and workpiece II on side E. Under the influence of the external load, the clamping rod 10 on side F tends to move downward, and the spring group in the adaptive force balancing mechanism 7 on side F is further compressed, causing the clamping rod 10 to retract upward, balancing part of the squeezing and pulling force on workpiece I and workpiece II on side F. The spring force group of the adaptive force balancing mechanism 7 in the clamping system not only provides a continuous and stable clamping force, but also automatically absorbs and balances the force caused by changing external loads, ensuring that workpiece I and workpiece II are always in a reliable connection state.

[0071] This invention relates to a dual-cylinder clamping system for clamping and monitoring the connection status of underwater equipment such as underwater risers, risers, submarine umbilical cables, and production pipelines after underwater installation and connection. Advantages include hydraulic drive, allowing for remote and fully automated operation, regardless of operating depth, eliminating the need for divers or underwater robots, and reducing the cost and risk of underwater equipment maintenance. The clamping device automatically adjusts and absorbs forces caused by changes in external loads, improving the connection reliability and service life of underwater equipment. Its mechanical structure makes it suitable for harsh seabed environments and allows for reusability, reducing manufacturing and operating costs. The self-locking mechanism maintains a constant clamping force throughout its lifespan without requiring continuous energy supply once the clamping operation is complete. This device is highly versatile and applicable to various underwater equipment such as underwater risers, risers, submarine umbilical cables, and production pipelines. Furthermore, by combining it with various cylinder sizes and energy storage component spring capacities, it can meet the specific clamping force requirements of underwater equipment.

[0072] The initial positioning and clamping of the dual-cylinder clamping system of this invention are achieved through a hydraulically driven clamping drive mechanism. Once the clamping force is adjusted to a predetermined value, a self-locking mechanism is activated to maintain the clamping position of the clamping drive mechanism. When the load on the clamped system changes, the adaptive force balancing mechanism reacts promptly, providing a constant clamping force throughout the entire use of the clamping device to reduce the impact of load changes caused by wind, waves, water flow, and mud surface collapse. Both the clamping drive mechanism and the self-locking mechanism of this clamping device are hydraulically operated and require energy supply only during positioning and initial clamping; no energy supply or regular maintenance is required during use.

Claims

1. A dual-cylinder clamping system, characterized in that, The device includes a dual-cylinder clamping device and a controller (27). The dual-cylinder clamping device includes a clamping head (12) and a clamping head hydraulic adjustment structure. The hydraulic input port of the clamping head hydraulic adjustment structure is connected to a hydraulic pump (28) through a hydraulic delivery pipe. An electric control valve is provided on the hydraulic delivery pipe. The hydraulic pump (28) and the electric control valve are respectively connected to the controller (27) through wires. The upper end of the clamping head hydraulic adjustment structure extends into the clamping head (12) and forms two clamping working surfaces with the inner upper surface of the clamping head (12). A pressure sensor (13) is provided at the upper end of the clamping head hydraulic adjustment structure. The pressure sensor (13) is connected to the controller (27) through a wire. The hydraulic adjustment structure of the clamping head includes a cylinder (2) located below the clamping head (12). The upper end cover (9) and the lower end cover (1) are fixedly installed at the upper and lower ends of the cylinder (2). The upper end cover (9) is fixedly connected to the lower end of the clamping head (12). The cylinder (2) is provided with 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 in sequence from top to bottom. The upper clamping drive mechanism includes an upper piston (8) which is slidably connected to the inner wall of the cylinder (2) below the upper end cover (9). The lower clamping drive mechanism includes a lower piston (6) which is slidably connected to the inner wall of the cylinder (2) below the adaptive force balancing mechanism (7). The adaptive force balancing mechanism (7) consists of multiple sets of springs evenly arranged between the upper surface of the lower piston (6) and the lower surface of the upper piston (8), with the two ends of the springs fixed to the upper surface of the lower piston (6) and the lower surface of the upper piston (8), respectively.

2. The dual-cylinder clamping system according to claim 1, characterized in that, The upper end of the upper clamping drive mechanism extends through the upper end cover (9) 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 (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 (2) corresponding to the self-locking mechanism and the lower end cover (1). An installation guide rod M is fixedly installed on the outer side wall of the lower end cover (1). The hydraulic port F and the hydraulic port E are respectively connected to the hydraulic pump (28) through hydraulic transmission pipes. An electric control valve f (31-1) and an electric control valve e (31-2) are respectively provided on the hydraulic transmission pipes corresponding to the hydraulic port F and the hydraulic port E. The electric control valve f (31-1) and the electric control valve e (31-2) are respectively connected to the controller (27) through wires. The lower clamping drive mechanism, the isolation plate ( 5) A cavity b is formed between the inner wall of the cylinder (2) and the cavity b. A hydraulic port B is provided on the side wall of the cylinder (2) corresponding to the cavity b. The hydraulic port B is connected to the hydraulic pump (28) through a hydraulic transmission pipe. An electric control valve b (31-3) is provided on the hydraulic transmission pipe corresponding to the hydraulic port B. The electric control valve b (31-3) is connected to the controller (27) through a wire. The self-locking mechanism is provided with position sensor a (29-1) and position sensor b (29-2) at the upper limit position and the lower limit position respectively in the cylinder (2). The position sensor a (29-1) and position sensor b (29-2) are connected to the collector (32) through a wire. The collector (32) is connected to the controller (27) through a wire. A temperature sensor (30) is provided on the outer wall of the cylinder (2). The temperature sensor (30) is connected to the collector (32) through a wire.

3. The dual-cylinder clamping system according to claim 2, characterized in that, The clamping head (12) is configured as a clamping head with a "C" shaped opening. An end cap assembly hole is provided on the lower wall of the clamping head (12). A retaining nut groove is provided around the end cap assembly hole on the inner surface of the lower wall of the clamping head (12). An extension end is provided in the middle of the upper surface of the upper end cap (9). The extension end extends into the end cap assembly hole and into the "C" shaped interior of the clamping head (12). A retaining nut (11) is connected to the extension end of the upper end cap (9) by means of a threaded connection. The retaining nut (11) is locked in the retaining nut groove. The clamping head (12) and the upper end cap (9) are fixed by the retaining nut (11) being locked in the retaining nut groove and by the clamping head (12) and the upper end cap (9) being locked together by the lower surface of the clamping head (12) and the upper surface of the upper end cap (9).

4. The dual-cylinder clamping system according to claim 3, characterized in that, A clamping rod (10) is connected to 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 provided 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 provided on the side wall of the cylinder (2) corresponding to the cavity a. The hydraulic port A is connected to the hydraulic pump (28) through a hydraulic transmission pipe. An electric control valve a (31-4) is provided on the hydraulic transmission pipe corresponding to the hydraulic port A. The electric control valve a (31-4) is connected to the controller (27) through a wire. A position sensor c (29-3) is provided in the cavity a at the upper limit position corresponding to the upper piston (8). The position sensor c (29-3) is connected to the collector (32) through a wire.

5. The dual-cylinder clamping system according to claim 4, characterized in that, 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 dual-cylinder clamping system according to claim 5, characterized in that, The isolation plate (5) is connected to the inner wall of the cylinder (2) by a threaded connection. 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 position sensor d (29-4) is provided in the cavity b at the lower limit position corresponding to the lower piston (6). The position sensor d (29-4) is connected to the collector (32) by a wire.

7. The dual-cylinder clamping system according to claim 6, characterized in that, The self-locking mechanism includes multiple locking sliders (3). The outer contour of each locking slider (3) is a conical surface, and the inner side of each locking slider (3) is a cylindrical surface. The multiple locking sliders (3) are assembled into a complete hollow frustum. The self-locking rod (4) passes through the hollow part of the hollow frustum. The outer diameter of the hollow frustum gradually decreases from top to bottom. The inner wall of the cylinder (2) is set with a conical surface that matches the hollow frustum. The upper 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 (2) and slide up and down on the inner wall of the cylinder (2). The upper push plate (22) and the lower push plate (24) are provided with radially spaced features at the position of each locking slider (3). The T-slots (22-1) are distributed, and each locking slider (3) has a T-slot corresponding to the T-slot (22-1) on its upper and lower surfaces. The T-slot slides radially within the T-slot (22-1) along the upper push plate (22) and the lower push plate (24). 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 (2), and the lower surface of the isolation plate (5). The hydraulic port E is located on the side wall of the cylinder (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 (2), and the upper surface of the lower end cover (1). The hydraulic port F is located on the side wall of the cylinder (2) corresponding to the cavity f. The cone angle of the locking slider (3), which is the self-locking angle, is γ. The locking slider (3) is made of deformable material.

8. The dual-cylinder clamping system according to claim 7, characterized in that, A wear-resistant ring (14) and a seal I (15) are arranged sequentially 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 (2). A seal III (17) is arranged between the upper piston (8) and the inner wall of the cylinder (2). A seal IV (18) is arranged between the lower piston (6) and the inner wall of the cylinder (2). A seal V (19) and a seal VI (20) are respectively arranged between the isolation plate (5), the self-locking rod (4), and the inner wall of the cylinder (2). A seal VII (21) and a seal VIII (23) are respectively arranged between the upper push plate (22), the self-locking rod (4), and the inner wall of the cylinder (2). A seal X (26) and a seal IX (25) are respectively arranged between the lower push plate (24), the self-locking rod (4), and the inner wall of the cylinder (2).

9. The working method of the dual-cylinder clamping system, characterized in that, The dual-cylinder clamping system of claim 8 specifically includes clamping operation, releasing operation, and external load balancing, wherein the clamping operation includes clamping operation and locking operation, and the releasing operation includes unlocking operation and releasing operation.

10. The working method of the dual-cylinder clamping system according to claim 9, characterized in that, After the workpiece I and workpiece II of the clamped product are connected, at least two double-cylinder clamping devices are placed next to the connection point of workpiece I and workpiece II respectively. The mounting guide rod M is fixed on workpiece II to ensure that the connection point of workpiece I and workpiece II is between the upper end of the clamping rod (10) and the upper surface of the inner C-shape of the clamping head (12). Then the clamping operation is performed. The end of the clamping head (12) away from the fixing nut (11) is the upper working plane during the clamping action. The clamping operation is specifically as follows: Clamping: The controller (27) controls the hydraulic pump (28) and the electric control valve b (31-3) to open, and input hydraulic oil into the cavity b through the hydraulic port B to apply pressure to the cavity b, so that the lower piston (6) drives the self-locking rod (4), the adaptive force balance mechanism (7), the upper piston (8) and the clamping rod (10) to move upward. The upper end of the clamping rod (10) and the upper surface inside the clamping head (12) clamp the connection between workpiece I and workpiece II. During the process, the pressure sensor (13) feeds back the pressure information to the controller (27) in real time. When the feedback pressure information reaches the preset value of the required clamping force and touches the position sensor d (29-4), the controller (27) controls the hydraulic pump (28) to stop inputting hydraulic oil, and the clamping of workpiece I and workpiece II is completed. Lock: Maintain the pressure inside cavity b. Control the hydraulic pump (28) and the corresponding electric valve e (31-2) of hydraulic port E to open through the controller (27). Hydraulic oil is delivered into cavity e to apply pressure to cavity e. Under the action of hydraulic oil, the locking slider (3) moves downward to the lower limit position and touches the position sensor b (29-2). During the downward movement of the locking slider (3) along the cone surface L of cylinder (2), it hugs the outer contour surface K of the self-locking rod (4) to achieve the locking state. The wedge surface of the locking slider (3) has a self-locking function, so that the self-locking rod (4) always maintains the locking position when subjected to downward axial external load. Thus, the locking of the clamping position is completed. The controller (27) controls the hydraulic pump (28) to depressurize cavity e and cavity b, disconnect the hydraulic source, and close the hydraulic pump (28), electric valve e (31-2) and electric valve b (31-3). The clamped product always maintains the clamping state and the locking state. When inspecting or retrieving clamped products, the locking rod must be unlocked and the clamping rod (10) retracted to release workpiece I and workpiece II. The specific release operation is as follows: Unlock: The controller (27) controls the hydraulic pump (28) and the solenoid valve b (31-3) to open. The hydraulic pump (28) injects hydraulic oil into the cavity b to apply pressure to the cavity b to the pressure corresponding to the clamping operation. The solenoid valve b (31-3) is closed. At the same time, the controller (27) controls the solenoid valve f (31-1) to open, injecting hydraulic oil into the cavity f to apply pressure to the cavity f to the preset pressure. After that, the solenoid valve f (31-1) is closed to maintain the pressure. When hydraulic oil is injected into the cavity f, the locking slider (3) gradually moves upward and moves radially away from the self-locking rod (4). Move to the upper limit position and touch the position sensor a (29-1) inside the cylinder (2). The outer contour surface K of the self-locking rod (4) is released and the self-locking rod (4) is in the unlocked state. The controller (27) controls the electric control valve b (31-3) to open and uses the hydraulic pump (28) to slowly reduce the pressure in the cavity b. The external load of the adaptive force balance mechanism (7) is released and it expands until the clamping force fed back by the pressure sensor (13) on the end face of the clamping rod (10) is zero. Then the pressure relief of the cavity b is completely completed and the electric control valve b (31-3) is closed. Thus, the unlocking of the clamping position is completed. Loosening: The controller (27) controls the opening of the solenoid valve f (31-1), and uses the hydraulic pump (28) to depressurize the cavity f. After completion, the controller (27) controls the closing of the solenoid valve f (31-1) and the opening of the solenoid valve a (31-4) to supply hydraulic oil to the cavity a and apply pressure to the cavity a. This causes the upper piston (8) to drive 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 trigger the position sensor d (29-4) in the cylinder (2). This completes the release of workpiece I and workpiece II. Then, the controller (27) controls the hydraulic pump (28) to depressurize the cavity a. After completion, the hydraulic pump (28) and the solenoid valve a (31-4) are closed to disconnect the hydraulic source. The external load balancing specifically refers to: When workpiece I is subjected to bending moment load, workpiece I tends to separate from workpiece II on one side. At this time, the spring force group of the compressed adaptive force balancing mechanism (7) pushes out the clamping rod (10) to provide a continuous and stable clamping force, so that workpiece I and workpiece II are always in a reliable connection state.

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