Concentric clamping system for oil pipe

Abstract

The invention discloses a concentric clamping system for an oil pipe, and relates to the technical field of oil pipe manufacturing, the concentric clamping system comprises two clamping assemblies which are oppositely arranged, and each clamping assembly is provided with a base body, a driving ring and a clamping arm which is in sliding connection with a guide hole of the base body. Initial concentric positioning of the oil pipe is achieved through the center hole of the base body, then the driving rings of the double clamping assemblies rotate at the same angle and the same number of turns, the clamping arms are driven by the transmission pieces to slide, the two ends of the oil pipe obtain balanced pre-tightening force, and axial symmetric constraint is formed. In the process, by means of the inclined guide hole surrounding the central axis of the base body, the clamping arm drives the clamping head to naturally achieve sliding, namely centering, when sliding, the clamping head can be accurately attached to the end face of the oil pipe without additional angle adjustment in the clamping process, and after clamping, track constraint formed by the guide hole can resist axial force and radial force when the oil pipe is overpressed. And the problem of sealing failure caused by deflection and bending of the oil pipe during hydraulic overpressure treatment is solved.

Description

Technical Field

[0001] This invention relates to the field of tubing manufacturing technology, and in particular to a concentric clamping system for tubing. Background Technology

[0002] The core load of high-pressure oil pipes is the circumferential stress generated by internal pressure. They are mostly manufactured using a cold-drawing process. During cold drawing, the plastic flow of the material is mainly along the axial direction, which makes the circumferential and radial strength and toughness of the oil pipe relatively weak.

[0003] Currently, the industry uses hydraulic overpressure treatment to achieve self-reinforcement. This involves applying a hydraulic load far exceeding the rated working pressure to the pipe, forcing the inner layer material of the pipe to undergo plastic deformation, forming a stable stress field of residual compressive stress in the inner layer and residual tensile stress in the outer layer, thereby improving the circumferential and radial performance of the oil pipe.

[0004] In the pretreatment stage of hydraulic overpressure treatment, the oil pipes at both ends are clamped by applying pre-tightening force through a radial clamping structure to counteract the axial thrust generated during overpressure.

[0005] If the preload at both ends of the clamping oil pipe is inconsistent, the side with weaker preload will not be able to fully resist the axial thrust due to insufficient constraint. Under the overpressure on the inner wall of the oil pipe, it will cause a slight radial deviation, which will lead to the bending of the oil pipe or the failure of the oil pipe seal (such as the sealing surface of a certain equipment and the oil pipe separating), affecting the effect of hydraulic overpressure treatment of the oil pipe. Summary of the Invention

[0006] The purpose of this invention is to improve the problem in the prior art where the axial constraint structure has inconsistent pre-tightening forces at both ends of the oil pipe, which causes the oil pipe to deflect along the side with weaker clamping force during overpressure treatment, resulting in sealing failure.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a concentric clamping system for oil pipes, comprising at least two clamping components arranged opposite to each other to jointly clamp both ends of a high-pressure oil pipe, wherein the clamping components include a base and a central hole penetrating the base itself for accommodating the oil pipe.

[0008] The substrate has multiple inclined guide holes arranged around its central axis. The clamping arm is slidably disposed in the guide holes, and its sliding trajectory forms an angle with the axis of the central hole.

[0009] The base is rotatably mounted with a drive ring and a transmission member connected between the drive ring and each of the clamping arms, wherein the drive ring and the transmission member form a transmission engagement.

[0010] The drive rings of both clamping assemblies rotate at the same angle and number of turns, driving all the clamping arms to move synchronously along their sliding trajectory through the transmission component, so that the clamping heads at the front end of each clamping arm simultaneously approach or move away from the axis of the central hole, thereby achieving synchronous concentric clamping or release of the clamping heads on the end face of the oil pipe.

[0011] In the above technical solution, before the hydraulic overpressure treatment is performed, the high-pressure oil pipe to be hydraulically overpressure treated is placed between two oppositely arranged clamping components, so that the two ends of the oil pipe are respectively inserted into the central holes of the base of the two clamping components. The coaxial design of the central holes ensures that the oil pipe is concentric with the clamping components in the initial state, laying the foundation for subsequent clamping.

[0012] When it is necessary to clamp the oil pipe to resist axial movement during overpressure, the drive rings of the two clamping components are rotated synchronously, and it is necessary to ensure that the rotation angle and number of rotations of the two drive rings are completely consistent. Since the drive ring and the transmission component connected to the tail end of the clamping arm form a transmission engagement, the rotational motion of the drive ring will be converted into the linear motion of the transmission component, which in turn drives the clamping arm connected to the transmission component to slide along the guide hole on the base.

[0013] The guide hole is inclined and is set around the central axis of the base, so that the sliding trajectory of the clamping arm forms a certain angle with the axis of the central hole. As the clamping arm slides along the guide hole, the clamping head at its front end will naturally approach the axis of the central hole at the same time.

[0014] Because the drive rings on both sides move synchronously, the sliding displacement of the clamping arms of the clamping components on both sides is completely consistent. In the end, all clamping heads can synchronously fit the two end faces of the oil pipe, realizing synchronous concentric clamping of the oil pipe and providing stable axial constraint for hydraulic overpressure treatment.

[0015] When the hydraulic overpressure treatment is completed and the oil pipe needs to be released, the two drive rings are rotated in opposite directions synchronously. The transmission component then drives the clamping arm to slide in the opposite direction along the guide hole. The clamping head will then move away from the axis of the central hole synchronously, releasing the clamping constraint on the oil pipe. At this time, the treated oil pipe can be taken out from the central hole.

[0016] The beneficial effects of this invention are: Initial concentric positioning of the tubing is achieved through the central hole of the base, preventing initial offset from affecting the clamping force. Then, the drive rings of the dual clamping components rotate at the same angle and with the same number of turns, driving the clamping arms to slide via a transmission component. This allows the tubing to receive balanced preload at both ends, forming a symmetrical axial constraint. During this process, the inclined guide hole surrounding the central axis of the base ensures that the clamping arms naturally center the clamping head as they slide. No additional angle adjustment is needed during clamping to precisely fit the tubing end face. Furthermore, the trajectory constraint formed by the guide hole after clamping resists axial and radial forces during tubing overpressure. This improves the sealing failure problem caused by tubing misalignment and bending during hydraulic overpressure treatment, effectively ensuring the circumferential and radial performance of the tubing after hydraulic overpressure treatment.

[0017] Furthermore, in this embodiment of the invention, the transmission component is a screw, one end of which is rotatably connected to the tail end of the clamping arm, and the other end forms a threaded pair with the internal thread of the drive ring, and the transmission engagement is a threaded engagement.

[0018] Furthermore, in this embodiment of the invention, the guide hole is a non-circular boring hole provided on the substrate, the substrate is provided with a guide groove communicating with the boring hole, and the screw is accommodated in the guide groove.

[0019] Furthermore, in this embodiment of the invention, the boring hole is an elliptical hole.

[0020] Furthermore, in this embodiment of the invention, a sliding seal is provided between the clamping arm and the guide hole.

[0021] Furthermore, in this embodiment of the invention, a scale or displacement sensor for indicating the relative rotational position of the two is provided between the substrate and the drive ring.

[0022] Furthermore, in this embodiment of the invention, the clamping head is detachably or adjustablely mounted on the front end of the clamping arm.

[0023] Furthermore, in this embodiment of the invention, the clamping head includes a fixed end and a contact end connected together. The contact end is used to contact the end face of the oil pipe, and the end face of the contact end is parallel to the end face of the high-pressure oil pipe to be clamped.

[0024] Furthermore, in this embodiment of the invention, the two sides of the fixed end protrude outwards compared to the middle part, the two protruding parts of the fixed end are embedded in the contact end, and the middle part of the fixed end is engaged with the contact end.

[0025] Furthermore, in this embodiment of the invention, the drive rings of the two clamping components are connected by a linkage mechanism to achieve synchronous rotation of the two. Attached Figure Description

[0026] Figure 1 This is a three-dimensional schematic diagram of a concentric clamping system for oil pipes according to an embodiment of the present invention.

[0027] Figure 2 This is another perspective view of the concentric clamping system for oil pipes according to an embodiment of the present invention.

[0028] Figure 3 This is a schematic diagram of the clamping head according to an embodiment of the present invention.

[0029] Figure 4 This is a schematic diagram illustrating the clamping motion effect of the concentric clamping system for oil pipes according to an embodiment of the present invention.

[0030] 10. Base, 11. Center hole, 12. Guide hole, 13. Clamping arm, 14. Drive ring, 15. Transmission component, 16. Clamping head, 16.1. Fixed end, 16.2. Contact end. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the present invention clear and complete, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some, not all, embodiments of the present invention, and are merely illustrative of the embodiments of the present invention. They are not intended to limit the embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] In the description of this invention, it should be noted that the terms "center," "middle," "upper," "lower," "left," "right," "inner," "outer," "top," "bottom," "side," "vertical," and "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "a," "first," "second," "third," "fourth," "fifth," and "sixth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] For purposes of simplicity and illustration, the principles of the embodiments are described primarily by way of example. In the following description, numerous specific details are set forth to provide a thorough understanding of the embodiments. However, it will be apparent to those skilled in the art that these embodiments may not be limited to these specific details in practice. In some instances, the structure of well-known concentric clamping systems for tubing has not been described in detail to avoid unnecessarily obscuring these embodiments. Furthermore, all embodiments can be used in combination with each other.

[0035] It should be noted that the accompanying drawings are part of the content of the instruction manual. The structural shapes, connections, fits, and positional relationships that can be clearly seen in the accompanying drawings should all be understood as part of the content of the instruction manual.

[0036] A concentric clamping system for oil tubing includes at least two clamping assemblies arranged opposite each other to jointly clamp both ends of a high-pressure oil tubing, such as... Figure 1 As shown, the clamping assembly includes a base 10 and a central hole 11 penetrating the base 10 itself for accommodating the oil pipe.

[0037] like Figure 1 , Figure 2 As shown, the base 10 has multiple inclined guide holes 12 arranged around its central axis, and the clamping arm 13 is slidably disposed in the guide holes 12, and its sliding trajectory forms an angle with the axis of the central hole 11.

[0038] The base 10 is rotatably mounted with a drive ring 14 and a transmission member 15 connected between the drive ring 14 and each clamping arm 13, and the drive ring 14 and the transmission member 15 form a transmission engagement.

[0039] Both clamping assemblies' drive rings 14 rotate at the same angle and number of turns, driving all clamping arms 13 to move synchronously along their sliding trajectory via the transmission component 15, such as... Figure 2 , Figure 3 , Figure 4 As shown, the clamping heads 16 at the front end of each clamping arm 13 simultaneously approach or move away from the axis of the central hole 11, thereby achieving synchronous concentric clamping or release of the clamping heads 16 on the end face of the oil pipe.

[0040] Specific implementation process: The high-pressure oil pipe to be subjected to hydraulic overpressure treatment is placed between two clamping components that are set up opposite each other, so that the two ends of the oil pipe are respectively inserted into the center hole 11 of the base 10 of the two clamping components. The coaxial design of the center hole 11 ensures that the oil pipe is concentric with the clamping components in the initial state, laying the foundation for subsequent clamping.

[0041] When it is necessary to clamp the oil pipe to resist axial movement during the overpressure process, the drive rings 14 of the two clamping components are rotated synchronously, and it is necessary to ensure that the rotation angle and number of rotations of the two drive rings 14 are completely consistent. Since the drive ring 14 and the transmission component 15 connected to the tail end of the clamping arm 13 form a transmission cooperation, the rotational motion of the drive ring 14 will be converted into the linear motion of the transmission component 15, which in turn drives the clamping arm 13 connected to the transmission component 15 to slide along the guide hole 12 on the base 10.

[0042] The guide hole 12 is inclined and is arranged around the central axis of the base 10, so that the sliding trajectory of the clamping arm 13 forms a certain angle with the axis of the central hole 11. During the process of the clamping arm 13 sliding along the guide hole 12, the clamping head 16 at its front end will naturally approach the axial direction of the central hole 11 at the same time.

[0043] Because the drive rings 14 on both sides move synchronously, the sliding displacement of the clamping arms 13 of the clamping components on both sides is completely consistent. In the end, all the clamping heads 16 can synchronously fit the two end faces of the oil pipe, realize synchronous concentric clamping of the oil pipe, and provide stable axial constraint for hydraulic overpressure treatment.

[0044] When the hydraulic overpressure treatment is completed and the oil pipe needs to be released, the two drive rings 14 are rotated in opposite directions synchronously. The transmission component 15 then drives the clamping arm 13 to slide in the opposite direction along the guide hole 12. The clamping head 16 will then move away from the axis of the central hole 11 synchronously, releasing the clamping constraint on the oil pipe. At this time, the treated oil pipe can be taken out from the central hole 11.

[0045] The advantages of this invention are that the initial concentric positioning of the oil pipe is achieved through the central hole 11 of the base 10, avoiding the impact of initial offset on the clamping force. Then, the drive ring 14 of the dual clamping assembly rotates at the same angle and with the same number of turns, driving the clamping arm 13 to slide via the transmission component 15, allowing both ends of the oil pipe to obtain a balanced preload and forming an axial symmetrical constraint. During this process, relying on the inclined guide hole 12 surrounding the central axis of the base 10, the clamping arm 13 drives the clamping head 16 to naturally achieve "sliding and centering" when sliding. During the clamping process, no additional angle adjustment is required to accurately fit the end face of the oil pipe. After clamping, the trajectory constraint formed by the guide hole 12 can also resist the axial and radial forces when the oil pipe is overpressured. This improves the problem of sealing failure caused by the oil pipe's skewing and bending during hydraulic overpressure treatment, and can effectively ensure the circumferential and radial performance of the oil pipe after hydraulic overpressure treatment.

[0046] It should be noted that the trajectory constraint structure formed by the multiple inclined guide holes 12 surrounding the central axis and the clamping arm 13 slidably installed in the boring hole can effectively resist the axial and radial forces of the oil pipe.

[0047] Specifically, after the clamping arm 13 of the left clamping assembly slides to the left to clamp the oil pipe, the axial movement of the oil pipe to the left will be restricted. Conversely, after the right clamping assembly clamps the oil pipe, the axial movement of the oil pipe to the right will also be restricted. Therefore, the axial displacement of the oil pipe is indirectly restricted.

[0048] Specifically, the clamping arm 13 is restricted by the guide hole 12. When the radial movement of the oil pipe is transmitted to the clamping arm 13, it will be restricted by the inner wall of the guide hole 12, thus indirectly restricting the radial displacement of the oil pipe.

[0049] Preferably, such as Figure 2 As shown, the transmission component 15 is a screw. One end of the screw is rotatably connected to the tail end of the clamping arm 13, and the other end forms a threaded pair with the internal thread of the drive ring 14. The transmission engagement is a threaded engagement.

[0050] When the clamping arm 13 needs to slide, the drive ring 14 on the base 10 is rotated. Since the transmission component 15 is a screw, with one end of the screw rotatably connected to the tail end of the clamping arm 13 and the other end forming a threaded pair with the internal thread of the drive ring 14, the rotational motion of the drive ring 14 is converted into the linear motion of the screw through the threaded engagement. The screw then drives the clamping arm 13, which is rotatably connected to it, to slide stably along the guide hole 12 on the base 10, thereby causing the clamping head 16 at the front end of the clamping arm 13 to approach or move away from the axis of the central hole 11, thus achieving the clamping or release of the oil pipe. Throughout the process, the engagement of the threaded pair ensures stable transmission between the rotation of the drive ring 14 and the sliding of the clamping arm 13, completing the power transmission without the need for an additional power conversion structure.

[0051] The screw and drive ring 14 are used as the threaded pair for transmission, which provides stable transmission efficiency and precise displacement control. It eliminates the need for a complex transmission conversion mechanism and simplifies the power transmission path.

[0052] Meanwhile, the rotational connection between the screw and the clamping arm 13 effectively prevents the clamping arm 13 from rotating with the screw, ensuring that the clamping arm 13 moves in a unique direction.

[0053] More preferably, the guide hole 12 is a non-circular boring hole provided on the base 10, and the base 10 is provided with a guide groove communicating with the boring hole, and the screw is accommodated in the guide groove.

[0054] The guide hole 12 is a non-circular bore on the base 10, and the base 10 has a guide groove communicating with the bore, in which the screw is housed. When the drive ring 14 drives the screw to make linear movements, the screw moves along the groove direction within the guide groove, preventing the screw from deviating from the preset movement trajectory. At the same time, the non-circular bore forms a circumferential constraint on the clamping arm 13, preventing the clamping arm 13 from rotating or radially shifting during sliding, ensuring that the clamping arm 13 always slides along the inclined direction of the bore. Under the dual constraints of the non-circular bore and the guide groove, the clamping arm 13 drives the clamping head 16 to stably approach or move away from the oil pipe, achieving more precise concentric clamping.

[0055] More preferably, the bore is an elliptical bore. When the clamping arm 13 slides along the elliptical bore, the inner wall of the elliptical bore forms a closer contact with the outer circumferential surface of the clamping arm 13. Compared with other non-circular bores, the elliptical bore can better accommodate the slight posture adjustments of the clamping arm 13 during sliding, while providing stable support for the clamping arm 13. During the process of the screw driving the clamping arm 13 to slide, the elliptical bore can reduce the local friction between the clamping arm 13 and the bore wall, making the sliding of the clamping arm 13 smoother; and the structural characteristics of the elliptical bore can reserve more reasonable space for the subsequent installation of sliding seals.

[0056] Preferably, a sliding seal is provided between the clamping arm 13 and the guide hole 12. When the clamping arm 13 slides along the guide hole 12, the sliding seal between the clamping arm 13 and the guide hole 12 tightly fits the contact surfaces of the two, filling the gap between the clamping arm 13 and the guide hole 12.

[0057] Preferably, a scale or displacement sensor is provided between the base 10 and the drive ring 14 to indicate their relative rotational position.

[0058] When the drive rings 14 of the two clamping components need to rotate synchronously, the operator can visually observe their relative rotational positions using the scale between the base 10 and the drive rings 14, ensuring that the angle and number of rotations of the drive rings 14 on both sides are the same. If a displacement sensor is used, the sensor detects the relative position of the base 10 and the drive rings 14 in real time and feeds the position signal back to the control system (a PLC control system that communicates with the sensor). The control system adjusts the rotation state of the drive rings 14 according to the feedback signal to avoid rotational deviation. During the clamping process, whether manually monitored by the scale or automatically detected by the displacement sensor, the rotation of the drive rings 14 can be monitored in real time, and any possible synchronization deviations can be corrected in time to ensure that the sliding displacement of the clamping arms 13 is consistent, achieving synchronous and concentric clamping of the oil pipe.

[0059] Preferably, the clamping head 16 is detachably or adjustablely mounted on the front end of the clamping arm 13.

[0060] When handling high-pressure oil pipes of different specifications, if the clamping head 16 does not fit well with the end face of the oil pipe, the clamping head 16 at the front end of the clamping arm 13 can be removed and replaced with a clamping head 16 that matches the current oil pipe specification. If a complete replacement is not required, the installation position or structure of the clamping head 16 can be adjusted to fit the end face size of the oil pipe. After replacement or adjustment, the clamping head 16 should be reinstalled at the front end of the clamping arm 13.

[0061] The detachable design enables quick assembly and disassembly of the clamping head 16 through standardized connection methods (such as bolt connection, snap connection, etc.), ensuring that clamping heads 16 of different specifications can be stably matched with clamping arms 13; the adjustable design allows the position or angle of the clamping head 16 to be finely adjusted according to the specifications of the oil pipe by reserving adjustment margins (such as elongated holes, adjusting screws, etc.), adapting to oil pipe end faces of different sizes.

[0062] Preferably, such as Figure 3 As shown, the clamping head 16 includes a fixed end 16.1 and a contact end 16.2 connected together. The contact end 16.2 is used to contact the end face of the oil pipe, and the end face of the contact end 16.2 is parallel to the end face of the high-pressure oil pipe to be clamped.

[0063] The clamping head 16 consists of a fixed end 16.1 and a contact end 16.2 connected together. When the clamping arm 13 moves the clamping head 16 closer to the oil pipe, the end face of the contact end 16.2, being parallel to the end face of the high-pressure oil pipe to be clamped, forms a comprehensive and uniform contact with the oil pipe end face. Compared to non-parallel contact, this parallel contact method allows the clamping force to be evenly distributed on the oil pipe end face, avoiding excessive or insufficient local force. During the clamping process, the contact end 16.2 always maintains a parallel posture against the oil pipe end face. Even if the clamping arm 13 experiences slight displacement due to sliding, the parallel end face design ensures that the contact area remains unchanged, maintaining the uniform transmission of clamping force and ensuring that the oil pipe remains in a stable clamping state during hydraulic overpressure treatment.

[0064] The end face of the contact end 16.2 is parallel to the end face of the tubing, so that when the two come into contact, they form a surface contact rather than a point contact or a line contact. Surface contact can maximize the contact area and evenly distribute the clamping force applied by the clamping head 16 to the end face of the tubing, avoiding local stress concentration.

[0065] More preferably, the two sides of the fixing end 16.1 protrude outward relative to the middle part, the two protruding parts of the fixing end 16.1 are fitted into the contact end 16.2, and the middle part of the fixing end 16.1 is fitted into the contact end 16.2.

[0066] Specifically, the protruding portions on both sides restrict the lateral displacement of the contact end 16.2, while the middle fitting portion further fixes the axial position of the contact end 16.2, ensuring that the contact end 16.2 remains relatively stable with the fixed end 16.1 during clamping. Even during hydraulic overpressure treatment, when the oil pipe generates a small reaction force due to internal pressure on the contact end 16.2, the double-fitting structure ensures that the contact end 16.2 will not shift its posture or detach from the fixed end 16.1, continuously maintaining the parallel and close contact between the end face of the contact end 16.2 and the end face of the oil pipe, ensuring that the clamping force is stably transmitted to the end face of the oil pipe.

[0067] The fitting of the protruding parts on both sides of the fixed end 16.1 with the contact end 16.2 essentially restricts the lateral degree of freedom of the contact end 16.2 perpendicular to the clamping direction through structural interlocking, preventing the contact end 16.2 from shifting left or right or up or down under force. Meanwhile, the fitting of the middle part of the fixed end 16.1 with the contact end 16.2 further restricts the axial degree of freedom of the contact end 16.2 along the clamping direction, preventing the contact end 16.2 from loosening back and forth under force. The two fitting methods work together to completely eliminate the unnecessary degrees of freedom of movement of the contact end 16.2, forming a more rigid integral structure between the contact end 16.2 and the fixed end 16.1. This structural design ensures that the clamping force is transmitted from the fixed end 16.1 to the contact end 16.2 without loss or offset, and is evenly applied to the end face of the tubing. It also avoids clamping surface deviation caused by changes in the posture of the contact end 16.2, providing structural mechanical protection for stable clamping.

[0068] Preferably, the drive rings 14 of the two clamping components are connected by a linkage mechanism to achieve synchronous rotation of the two.

[0069] Linkage mechanisms, such as gear linkages, chain linkages, and linkages, establish a kinematic connection between the two drive rings 14 through rigid connections or meshing, allowing the rotation of one drive ring 14 to be directly transmitted to the other without any loss or deviation in rotational amount during the transmission. This forced synchronization method avoids delays or errors that may be caused by manual control or independent drive. The mechanical structure ensures that the rotational angular velocity and rotation amount of the two drive rings 14 are exactly the same, thereby ensuring the consistency of the sliding displacement of the clamping arm 13 and providing mechanical guarantee for the balance of preload at both ends of the oil pipe.

[0070] Although the illustrative specific embodiments of the present invention have been described above to enable those skilled in the art to understand the invention, the invention is not limited to the scope of the specific embodiments. For those skilled in the art, all inventions utilizing the concept of the present invention are protected as long as various variations are within the spirit and scope of the invention as defined and determined by the appended claims.

Claims

1. A concentric clamping system for oil pipes, comprising at least two clamping assemblies arranged opposite each other to jointly clamp both ends of a high-pressure oil pipe, characterized in that, The clamping assembly includes a base and a central hole penetrating the base itself for accommodating an oil pipe; The substrate has multiple inclined guide holes arranged around its central axis, and the clamping arm is slidably disposed in the guide holes, with its sliding trajectory forming an angle with the axis of the central hole; The base is rotatably mounted with a drive ring and a transmission component connected between the drive ring and each of the clamping arms, wherein the drive ring and the transmission component form a transmission engagement. The drive rings of both clamping assemblies rotate at the same angle and number of turns, driving all the clamping arms to move synchronously along their sliding trajectory through the transmission component, so that the clamping heads at the front end of each clamping arm simultaneously approach or move away from the axis of the central hole, thereby achieving synchronous concentric clamping or release of the clamping heads on the end face of the oil pipe.

2. The concentric clamping system for oil pipes according to claim 1, characterized in that, The transmission component is a screw, one end of which is rotatably connected to the tail end of the clamping arm, and the other end forms a threaded pair with the internal thread of the drive ring. The transmission engagement is a threaded engagement.

3. The concentric clamping system for oil pipes according to claim 2, characterized in that, The guide hole is a non-circular boring hole provided on the substrate, and the substrate is provided with a guide groove communicating with the boring hole, and the screw is housed in the guide groove.

4. The concentric clamping system for oil pipes according to claim 3, characterized in that, The boring hole is an elliptical hole.

5. The concentric clamping system for oil pipes according to claim 1, characterized in that, A sliding seal is provided between the clamping arm and the guide hole.

6. The concentric clamping system for oil pipes according to claim 1, characterized in that, A scale or displacement sensor is provided between the base and the drive ring to indicate their relative rotational position.

7. The concentric clamping system for oil pipes according to claim 1, characterized in that, The clamping head is detachably or adjustablely mounted on the front end of the clamping arm.

8. The concentric clamping system for oil pipes according to claim 1, characterized in that, The clamping head includes a fixed end and a contact end connected together. The contact end is used to contact the end face of the oil pipe, and the end face of the contact end is parallel to the end face of the high-pressure oil pipe to be clamped.

9. The concentric clamping system for oil pipes according to claim 8, characterized in that, The two sides of the fixed end protrude outwards compared to the middle part, the two protruding parts of the fixed end are fitted into the contact end, and the middle part of the fixed end is engaged with the contact end.

10. The concentric clamping system for tubing according to claim 1, characterized in that, The drive rings of the two clamping components are connected by a linkage mechanism to achieve synchronous rotation of the two.

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