Self-locking quick connector
By designing a self-locking fast joint, a stable connection under high water pressure is achieved using the mating of the clip and the fixing ring and the fluid pressure, and the initial self-locking force is provided in the initial stage, solving the problem of existing bar-locking fast joints falling off and unstable connection under high water pressure.
Patent Information
- Application Number
- CN202422424778.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-08
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-10-08
AI Technical Summary
Existing poker fast joints are prone to fall off under high water pressure, resulting in water leakage in the pipeline, unable to meet the needs of high water pressure, and in the initial stage the fluid is not sufficient to provide sufficient pressure, which poses a risk of unstable connections.
A self-locking quick joint is designed, including a tubular body and a joint assembly. Through the cooperation of the card member and the fixing ring, the inner cavity of the card member is radially contracted by fluid pressure, thereby achieving a tight connection of the outer duct, and a self-locking structure is provided at the first interface end to provide an initial self-locking force.
Under high water pressure, the self-locking fast joint can maintain a stable connection to avoid water leakage. In the initial stage, even if the fluid pressure is insufficient, the connection stability can be ensured and the use needs of high water pressure can be met.
Smart Images
Figure CN223035949U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of pipe joints, and particularly relates to a self-locking quick joint. Background Art
[0002] To connect PE pipe materials, traditionally a cap-type quick joint is used for connection. However, during use under high water pressure, the cap-type joint will fall off, unable to meet the requirements of high water pressure use, and at the same time causing water leakage in the pipeline, which will bring property losses and a bad user experience to users.
[0003] For this reason, people have invented a new type of quick joint that can improve the locking ability between the tubular body and the joint when the fluid pressure of the external pipe increases. However, this joint lacks locking force in the initial stage, and the fluid cannot provide sufficient pressure in the initial stage, especially there is a risk of unstable connection in the case of large water pressure changes. Summary of the Utility Model
[0004] In order to overcome the deficiencies of the prior art, the purpose of the utility model is to provide a self-locking quick joint, which has the characteristic that the greater the fluid pressure of the external pipe, the tighter the tubular body and the joint are locked, and can provide initial self-locking force to improve the connection stability between the tubular body and the joint under various pressure conditions.
[0005] The purpose of the utility model is realized by adopting the following technical scheme:
[0006] A self-locking quick joint includes a tubular body and a joint assembly;
[0007] The tubular body has a first interface end, and a cavity is formed inside for fluid to pass through; the joint assembly includes a fixing ring and a clamping member; the fixing ring is sleeved on the first interface end, both ends of the clamping member respectively form a first end and a second end, and an inner cavity is formed inside for an external pipe to penetrate into; the first end of the clamping member penetrates from the first interface section into the fixing ring; the clamping member can axially translate relative to the fixing ring. When the clamping member moves towards the direction close to the fixing ring, the inner cavity of the clamping member expands radially. When the clamping member moves towards the direction away from the fixing ring, the inner cavity of the clamping member contracts radially;
[0008] A self-locking structure is arranged at the connection between the first interface end of the tubular body and the clamping member, and the self-locking structure is used to limit the clamping member from moving towards the direction close to the fixing ring.
[0009] In an optional implementation manner, the clamping member has a locked state and an unlocked state, and the self-locking structure is used to switch the clamping member between the locked state and the unlocked state; when the clamping member is in the unlocked state, the inner cavity of the clamping member expands radially; when the clamping member is in the locked state, the inner cavity of the clamping member contracts radially.
[0010] In an alternative embodiment, the self-locking structure includes a self-locking convex position and a self-locking clamping block; the self-locking convex position is formed at the first interface end of the tubular body, and the self-locking convex position is a protrusion axially from the end face of the first interface end; the self-locking clamping block is formed at the second end of the clamping member, and the self-locking clamping block extends radially from the circumferential surface of the second end; by rotating the self-locking clamping block to the self-locking convex position, the inner cavity of the clamping member shrinks radially, so that the clamping member switches to the locked state. After rotation in place, the self-locking convex position and the self-locking clamping block abut against each other, restricting the movement of the clamping member in the direction close to the fixing ring, and realizing the locking function.
[0011] In an alternative embodiment, the self-locking structure further includes an unlocking concave position, which is formed at the first interface end of the tubular body, and the unlocking concave position is an axially extending groove on the end face of the first interface end; by rotating the self-locking clamping block to the unlocking concave position, the inner cavity of the clamping member expands radially, so that the clamping member switches to the unlocked state.
[0012] In an alternative embodiment, a transition surface is formed between the self-locking convex position and the unlocking concave position. The transition surface includes an inclined section, and arc-shaped connection sections are respectively formed at both ends of the inclined section; the angle formed by the inclined section and the radial cross-section of the tubular body is a, where 0 < a < 90°.
[0013] In an alternative embodiment, a limiting block is provided on the self-locking convex position, and the limiting block and the transition surface are respectively arranged on opposite sides of the self-locking convex position; the limiting block is used to limit further rotation of the self-locking clamping block.
[0014] In an alternative embodiment, the number of both the self-locking convex positions and the unlocking concave positions is 2, and the self-locking convex positions and the unlocking concave positions are symmetrically arranged at the center of the end face of the first interface end; the number of the self-locking clamping blocks is 2, and the two self-locking clamping blocks are symmetrically arranged at the second end of the clamping member.
[0015] In an alternative embodiment, a limiting strip is provided on the outer side of the clamping member; a limiting groove is provided on the inner side of the first interface end of the tubular body; when the clamping member switches to the unlocked state, the limiting strip is engaged in the limiting groove.
[0016] In an alternative embodiment, the fixing ring is connected to the tubular body through a clamping structure; the clamping structure includes a hook groove and a hook ear; the hook groove is formed on the inner wall of the tubular body, and the hook ear is formed on the outer wall of the fixing ring, and the hook ear is hooked in the hook groove;
[0017] A positioning groove is provided on the inner end face of the first interface end of the tubular body, and the positioning groove is adapted to the hook ear;
[0018] The fixing ring includes a first annular portion and a second annular portion. The interior of the second annular portion is in a flared shape. One end with a smaller inner diameter of the flared shape is connected to one end of the first annular portion. The inner diameter of the end with the smaller inner diameter of the flared shape is larger than the inner diameter of the first annular portion, forming an annular step. The inner diameter of the outer end face of the fixing ring is smaller than the inner diameter of the inner end face, and the fixing ring is in a flared shape.
[0019] An annular step is provided inside the tubular body, and a sealing ring is provided on the annular step. The fixing ring is arranged on the sealing ring.
[0020] In an alternative embodiment, a plurality of claws are provided at the first end portion of the clamping member. The claws extend along the axial direction of the clamping member. Hook pieces for clamping the external connecting pipe are provided on the inner wall of the claws. Annular protrusions are provided on the outer wall of the claws. A notch is formed between adjacent claws. The notch is arranged along the axial direction of the clamping member, so that adjacent claws approach or move away from each other, realizing radial contraction or radial expansion of the inner cavity.
[0021] Compared with the prior art, the beneficial effects of the present utility model are as follows:
[0022] For the self-locking quick connector of the present utility model, the connection between the self-locking quick connector and the external pipeline is realized by inserting the end portion of the external connecting pipe into the inner cavity of the clamping member. When the fluid pressure increases, the fluid pressure pushes the clamping member to move away from the fixing ring, so that the inner cavity of the clamping member radially contracts, clamping the external connecting pipe in the inner cavity. At the same time, the fixing ring radially expands under the reaction force and is tightly connected to the tubular body. By providing a self-locking structure at the connection between the first interface end and the clamping member, the initial relative position between the clamping member and the fixing ring is locked, restricting the movement of the clamping member towards the fixing ring, providing an initial self-locking force for the tubular body and the joint assembly, and stably connecting the external pipeline, the joint assembly and the tubular body. Even in the initial stage when the fluid is not sufficient to provide enough pressure, or when the water pressure changes greatly, the connection stability can be ensured. Description of the Drawings
[0023] Figure 1 It is a perspective view of the self-locking quick connector of Embodiment 1;
[0024] Figure 2 It is a front view of the self-locking quick connector of Embodiment 1;
[0025] Figure 3 It is a cross-sectional view of the self-locking quick connector of Embodiment 1 along the A-A section;
[0026] Figure 4 It is an installation schematic diagram of each component of the self-locking quick connector of Embodiment 1;
[0027] Figure 5Schematic structural diagram of the tubular body of the self-locking quick connector of Embodiment 1;
[0028] Figure 6 Schematic structural diagram of the clamping member of the self-locking quick connector of Embodiment 1;
[0029] Figure 7 Schematic structural diagram of the self-locking quick connector of Embodiment 1 in the locked state;
[0030] Figure 8 Schematic structural diagram of the self-locking quick connector of Embodiment 1 in the unlocked state.
[0031] In the figure: 10, tubular body; 11, self-locking convex position; 12, unlocking concave position; 13, transition surface; 14, limiting block; 15, limiting groove; 16, hook groove; 17, positioning groove; 20, fixing ring; 21, hook ear; 30, clamping member; 31, inner cavity; 32, first end; 33, second end; 34, self-locking clamping block; 35, limiting strip; 36, clamping claw; 37, hook piece; 38, notch; 40, sealing ring. Detailed implementation manners
[0032] Next, in combination with the drawings and the detailed implementation manners, the present utility model will be further described. It should be noted that, on the premise of no conflict, the following-described embodiments or technical features can be arbitrarily combined to form new embodiments. Except as otherwise specifically stated, the materials and equipment used in this embodiment can be purchased from the market. The examples of the embodiments are shown in the drawings, in which the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions from beginning to end. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application and should not be construed as a limitation to the present application.
[0033] In the description of the present application, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application. In the description of the present application, the meaning of "a plurality" is two or more, unless otherwise specifically and precisely defined.
[0034] In the description of the present application, it should be noted that unless otherwise clearly specified and defined, the terms "connected", "communicated", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, or connected through an intermediate medium, or it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.
[0035] The terms "first", "second", etc. in the specification, claims, and the above-mentioned drawings of the present application are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units does not have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.
[0036] Embodiment 1:
[0037] Please refer to Figure 1-8 , this embodiment provides a self-locking quick connector, including a tubular body 10 and a joint assembly; the joint assembly is used to connect with an external pipe.
[0038] Both ends of the tubular body 10 respectively form a first interface end and a second interface end, and a cavity for fluid to pass through is formed inside.
[0039] The joint assembly includes a fixing ring 20 and a clamping member 30; the fixing ring 20 is inserted through the first interface end, both ends of the clamping member 30 respectively form a first end 32 and a second end 33, and an inner cavity 31 for the external pipe to penetrate is formed inside; the first end 32 of the clamping member 30 penetrates from the first interface section into the fixing ring 20; the clamping member 30 can axially translate relative to the fixing ring 20. When the clamping member 30 moves in the direction close to the fixing ring 20, the inner cavity 31 of the clamping member 30 expands radially, and when the clamping member 30 moves in the direction away from the fixing ring 20, the inner cavity 31 of the clamping member 30 contracts radially;
[0040] A self-locking structure is provided at the connection between the first interface end of the tubular body 10 and the clamping member 30, and the self-locking structure is used to limit the movement of the clamping member 30 in the direction close to the fixing ring 20. Further, the clamping member 30 has a locked state and an unlocked state, and the self-locking structure is used to switch the clamping member 30 between the locked state and the unlocked state; when the clamping member 30 is in the unlocked state, the inner cavity 31 of the clamping member 30 expands radially; when the clamping member 30 is in the locked state, the inner cavity 31 of the clamping member 30 contracts radially.
[0041] Specifically, the self-locking structure includes a self-locking convex position 11, an unlocking concave position 12, and a self-locking clamping block 34.
[0042] The self-locking convex position 11 is formed at the first interface end of the tubular body 10, and the self-locking convex position 11 is a protrusion axially from the end face of the first interface end; the unlocking concave position 12 is formed at the first interface end of the tubular body 10, and the unlocking concave position 12 is a groove axially from the end face of the first interface end.
[0043] The self-locking clamping block 34 is formed at the second end portion 33 of the clamping member 30, and the self-locking clamping block 34 extends radially from the circumferential surface of the second end portion 33.
[0044] During use, rotate the self-locking clamping block 34 to the unlocking concave position 12 to switch the clamping member 30 to the unlocking state. When the clamping member 30 is in the unlocking state, that is, the clamping member 30 is in a position close to the fixing ring 20, the inner cavity 31 expands radially, facilitating the insertion of the end of the outer connection pipe into the inner cavity 31. After the outer connection pipe is inserted in place, rotate the self-locking clamping block 34 in the direction of the self-locking convex position 11, driving the clamping member 30 to move away from the fixing ring 20, causing the inner cavity 31 to contract radially, switching the clamping member 30 to the locking state, clamping the outer connection pipe tightly in the inner cavity 31, and at the same time, the fixing ring 20 is in close fit with the tubular body 10; after rotation in place, the self-locking convex position 11 and the self-locking clamping block 34 abut against each other, restricting the clamping member 30 from moving in the direction close to the fixing ring 20, realizing the locking function, providing an initial self-locking force for the tubular body 10 and the joint assembly, and ensuring that the pipeline can provide sufficient connection stability when the fluid pressure is insufficient in the initial stage or when the water pressure changes greatly. During the use process, when the fluid pressure increases, the fluid pressure further pushes the clamping member 30 to move away from the fixing ring 20, thereby causing the inner cavity 31 of the clamping member 30 to contract radially, clamping the outer connection pipe tightly in the inner cavity 31, and at the same time, the fixing ring 20 expands radially under the reaction force, realizing the characteristic that the greater the fluid pressure of the outer connection pipe, the tighter the tubular body 10 and the joint assembly are locked.
[0045] Furthermore, a transition surface 13 is formed between the self-locking convex position 11 and the unlocking concave position 12. The transition surface 13 includes an inclined section, and arc-shaped connection sections are respectively formed at both ends of the inclined section; the included angle between the inclined section and the radial cross-section of the tubular body 10 is a, 0 < a < 90°, preferably, a = 45°. By providing the transition surface 13 between the self-locking convex position 11 and the unlocking concave position 12, the transition surface 13 can be smoothly switched between the locking state and the unlocking state.
[0046] A limiting block 14 is provided on the self-locking convex position 11 of this embodiment, and the limiting block 14 and the transition surface 13 are respectively arranged on two opposite sides of the self-locking convex position 11; the limiting block 14 is used to limit the further rotation of the self-locking block 34. By providing the limiting block 14 at the end of the self-locking convex position 11, when the self-locking block 34 rotates to the self-locking convex position 11 in place, the edge of the self-locking block 34 abuts against the side surface of the limiting block 14, restricting the further rotation of the self-locking block 34, thereby preventing the self-locking block 34 from rotating and falling into the unlocking concave position 12.
[0047] The number of the self-locking convex positions 11 and the unlocking concave positions 12 in this embodiment is both 2, and the self-locking convex positions 11 and the unlocking concave positions 12 are symmetrically arranged at the center of the end surface of the first interface end; correspondingly, the number of the self-locking blocks 34 is 2, and the two self-locking blocks 34 are symmetrically arranged at the second end portion 33 of the card member 30, so that the two self-locking blocks 34 are fixed to the second end portion 33 of the card member 30 in a wing shape. The central symmetry arrangement of the self-locking blocks 34 is beneficial to the exertion of force for clamping with both hands and is convenient for operation. In other embodiments, the self-locking convex positions 11, the unlocking concave positions 12 and the self-locking blocks 34 can also be correspondingly set to an even number and implemented according to the actual situation, which can be understood by those skilled in the art. Further, a plurality of anti-slip grooves can be provided on the outer side of the self-locking block 34 to increase the friction during hand-held rotation and facilitate operation.
[0048] A limiting strip 35 is provided on the outer side of the card member 30; a limiting groove 15 is provided on the inner side of the first interface end of the tubular main body 10; when the card member 30 is switched to the unlocking state, the limiting strip 35 is clamped in the limiting groove 15 under the action of elastic force.
[0049] Specifically, the fixing ring 20 is connected to the tubular main body 10 through a clamping structure; the clamping structure includes a hook groove 16 and a hook ear 21; the hook groove 16 is formed on the inner wall of the tubular main body 10, the hook ear 21 is formed on the outer wall of the fixing ring 20, and the hook ear 21 is hooked in the hook groove 16. At least one positioning groove 17 is provided on the inner end surface of the first interface end of the tubular main body 10, and the positioning groove 17 basically matches the outer shape of the hook ear 21. The hook ear 21 at the end of the fixing ring 20 is aligned with the positioning groove 17 to perform positioning and convenient installation with the tubular main body 10 at a predetermined angle, improving the assembly rate.
[0050] The fixing ring 20 includes a first annular portion and a second annular portion. The inside of the second annular portion is in a trumpet shape. The end with a smaller inner diameter of the trumpet shape is connected to one end of the first annular portion, and the inner diameter of the end with a smaller inner diameter of the trumpet shape is larger than the inner diameter of the first annular portion, forming an annular step; the inner diameter of the outer end surface of the fixing ring 20 is smaller than the inner diameter of the inner end surface, and the fixing ring 20 is in a trumpet shape;
[0051] An annular step is provided inside the tubular body 10, and a sealing ring 40 is provided on the annular step. In this embodiment, the number of the sealing rings 40 is 2, and the fixing ring 20 is provided on the sealing ring 40.
[0052] A plurality of claws 36 are provided at the first end portion 32 of the clamping member 30. The claws 36 extend along the axial direction of the clamping member 30. Hook pieces 37 for clamping an external pipe are provided on the inner walls of the claws 36. Annular protrusions are provided on the outer walls of the claws 36. A notch 38 is formed between adjacent claws 36. The notch 38 is arranged along the axial direction of the clamping member 30, so that adjacent claws 36 approach or move away from each other, realizing radial contraction or radial expansion of the inner cavity 31.
[0053] Further, a joint assembly as described in this embodiment may also be provided at the second interface end of the tubular body 10. The tubular body 10 may also be provided with three interface ends in a "T" shape or a "Y" shape; or four interface ends in a "cross" shape may be provided, so as to meet different pipe connection requirements.
[0054] Preferably, the tubular body 10, the fixing ring 20 and the clamping member 30 are injection molded from POM, PP, ABS or PC materials. Since the present utility model uses a structure in which the greater the fluid pressure of the external pipe, the tighter the clamping of the tubular body 10 and the joint assembly, relatively inexpensive materials can be used, saving costs in terms of raw materials.
[0055] For other structural forms in this solution, reference may be made to the prior art and will not be elaborated here.
[0056] Although certain components and embodiments of the present application have been illustrated and described, many modifications and changes (e.g., changes in the size, dimensions, structure, shape and proportion of each component, installation arrangement, material use, color, orientation, etc.) can be conceived by those skilled in the art without actually departing from the scope and spirit of the claims.
[0057] Finally, it should be noted that the above embodiments are only preferred embodiments of the present utility model, and the scope of protection of the present utility model cannot be limited thereby. Any non-substantive changes and substitutions made by those skilled in the art based on the present utility model fall within the scope of protection required by the present utility model.
Claims
1. A self-locking quick connector, characterized in that: It includes a tubular body and a joint assembly; The tubular body has a first interface end, and a cavity is formed inside for fluid to pass through; the joint assembly includes a fixing ring and a clamp; the fixing ring is arranged on the first interface end, and the two ends of the clamp respectively form a first end and a second end, and an inner cavity is formed inside for the external tube to pass through; the first end of the clamp is inserted into the fixing ring from the first interface section; the clamp can be axially translated relative to the fixing ring, and when the clamp moves in a direction close to the fixing ring, the inner cavity of the clamp expands radially, and when the clamp moves in a direction away from the fixing ring, the inner cavity of the clamp contracts radially; A self-locking structure is provided at the connection between the first interface end of the tubular body and the clamping piece, and the self-locking structure is used to limit the movement of the clamping piece in a direction close to the fixing ring.
2. A self-locking quick connector according to claim 1, characterized in that: The card has a locked state and an unlocked state, and the self-locking structure is used to switch the card between the locked state and the unlocked state; when the card is in the unlocked state, the inner cavity of the card radially expands; when the card is in the locked state, the inner cavity of the card radially contracts.
3. A self-locking quick connector according to claim 2, characterized in that: The self-locking structure includes a self-locking protrusion and a self-locking block; the self-locking protrusion is formed at the first interface end of the tubular body, and the self-locking protrusion is axially protruded by the end face of the first interface end; the self-locking block is formed at the second end of the card, and the self-locking block radially extends from the circumferential surface of the second end; by rotating the self-locking block to the self-locking protrusion, the inner cavity of the card is radially contracted, so that the card is switched to a locked state, and after rotating into place, the self-locking protrusion and the self-locking block abut against each other, limiting the movement of the card in the direction close to the fixing ring, thereby realizing the locking function.
4. A self-locking quick connector according to claim 3, characterized in that: The self-locking structure also includes an unlocking recess, which is formed at the first interface end of the tubular body, and the unlocking recess is an axial groove on the end face of the first interface end; by rotating the self-locking block to the unlocking recess, the inner cavity of the card expands radially, so that the card is switched to an unlocked state.
5. A self-locking quick connector according to claim 4, characterized in that: A transition surface is formed between the self-locking convex position and the unlocking concave position, and the transition surface includes an inclined section, and arc-shaped connecting sections are formed at both ends of the inclined section; the angle formed by the inclined section and the radial cross section of the tubular body is a, 0 <a<90°。 6. A self-locking quick connector according to claim 5, characterized in that: A limit block is arranged on the self-locking convex position, and the limit block and the transition surface are arranged on two opposite sides of the self-locking convex position respectively; the limit block is used to limit the further rotation of the self-locking block.
7. A self-locking quick connector according to claim 4, characterized in that: The number of the self-locking protrusions and unlocking recesses are both 2, and the self-locking protrusions and unlocking recesses are centrally symmetrically arranged on the end surface of the first interface end; the number of the self-locking card blocks is 2, and the two self-locking card blocks are centrally symmetrically arranged on the second end of the card.
8. A self-locking quick connector according to claim 2, characterized in that: A limiting strip is arranged on the outside of the clamp; a limiting groove is arranged on the inside of the first interface end of the tubular body; when the clamp is switched to an unlocked state, the limiting strip is engaged in the limiting groove.
9. A self-locking quick connector according to claim 1, characterized in that: The fixing ring is connected to the tubular body through a snap-fit structure; the snap-fit structure includes a hook groove and a hook ear; the hook groove is formed on the inner wall of the tubular body, the hook ear is formed on the outer wall of the fixing ring, and the hook ear is hooked in the hook groove; The inner end surface of the first interface end of the tubular body is provided with a positioning groove, and the positioning groove is adapted to the hook ear; The fixing ring comprises a first annular portion and a second annular portion, the interior of the second annular portion is trumpet-shaped, the end of the trumpet-shaped portion with a smaller inner diameter is connected to one end of the first annular portion, the inner diameter of the end of the trumpet-shaped portion with a smaller inner diameter is larger than the inner diameter of the first annular portion, forming an annular step; the inner diameter of the outer end surface of the fixing ring is smaller than the inner diameter of the inner end surface, and the fixing ring is trumpet-shaped; An annular step is arranged inside the tubular body, a sealing ring is arranged on the annular step, and the fixing ring is arranged on the sealing ring.
10. A self-locking quick connector according to claim 2, characterized in that: A plurality of claws are provided at the first end of the clamp, and the claws extend along the axial direction of the clamp. A hook piece for clamping the external tube is provided on the inner wall of the claw, and an annular protrusion is provided on the outer wall of the claw. A notch is formed between adjacent claws, and the notch is arranged along the axial direction of the clamp, so that adjacent claws are brought closer to or farther away from each other, thereby realizing radial contraction or radial expansion of the inner cavity.