A self-locking pipe joint

Abstract

The present invention discloses a self-locking pipe joint, which belongs to a pipeline connection device; it includes a first connector, a second connector and a compression nut with a pipeline passage in the middle; the outer ends of the first connector and the second connector are respectively fixedly connected to the pipelines on both sides, and the inner ends are butted against each other; the compression nut is sleeved on the outer surfaces of the first connector and the second connector through a thread; the outer diameter of the first connector on the side close to the butt end gradually decreases along the butt direction to form a variable diameter surface, and an annular opening groove is provided in the middle of the variable diameter surface; the inner surface of the butt end of the first connector is a conical surface or a spherical surface; the outer surface of the butt end of the second connector is a conical surface or a spherical surface; a spherical seal or a conical seal or a ball-cone seal is formed by the outer surface of the butt end of the second connector contacting the inner surface of the butt end of the first connector. The butt sealing surfaces of the first connector and the second connector of the present invention have a self-locking function, which can effectively prevent loosening and improve the sealing effect.

Description

Technical Field

[0001] The invention relates to a pipeline connecting device, in particular to a self-locking pipe joint. Background Art

[0002] Pipe fittings are the connection tools between pipes and are the detachable connection points between components and pipes. They play an indispensable and important role in pipe fittings. They are one of the main components of hydraulic pipes and are widely used in various fields.

[0003] In traditional pipe joint structures, locking wires are usually designed to prevent the pipe joints from loosening, but the locking wires often only work on external fixings and do not prevent the internal pipe seals from loosening. During long-term use, especially in complex working environments such as vibration, the sealing effect of the sealing surface in the pipe joint will gradually decrease or fail, resulting in oil leakage or malfunction of the pipeline. In other words, the service life of the pipe joint is reduced or the maintenance time is shortened, affecting normal use. Summary of the invention

[0004] In order to overcome the above-mentioned defects of the prior art, the present invention aims to provide a self-locking pipe joint which can reduce the influence of vibration, is suitable for complex environments and has good sealing performance.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A self-locking pipe joint comprises a first connector with a pipeline passage in the middle, a second connector and a compression nut; the outer ends of the first connector and the second connector are respectively fixedly connected to the pipelines on both sides, and the inner ends are butted against each other; the outer surface of the first connector is provided with a clamping platform, and the outer surface of the second connector is provided with an external thread, one end of the compression nut is sleeved on the second connector through a thread, and the other end abuts against the clamping platform; the outer diameter of the first connector on the side close to the butt end gradually decreases along the butt direction to form a reducing surface, and an annular opening groove is provided in the middle of the reducing surface; the inner surface of the butt end of the first connector is a conical surface or a spherical surface; the outer surface of the butt end of the second connector is a conical surface or a spherical surface; a spherical seal, a conical seal or a ball-cone seal is formed by the outer surface of the butt end of the second connector abutting against the inner surface of the butt end of the first connector.

[0007] Preferably, the diameter-changing surface is a conical surface or an arc-shaped surface.

[0008] Preferably, the cross section of the opening groove is V-shaped.

[0009] Preferably, the upper part of the groove wall of the open groove is vertically recessed toward both sides to form an annular groove, and an elastic metal ring matching the shape of the annular groove is arranged in the annular groove.

[0010] Preferably, the tube body of the first connecting member is provided with a first cavity set between the opening groove and the butt end.

[0011] Preferably, the first cavity set consists of a plurality of cavities distributed circumferentially.

[0012] Preferably, the first cavity set is at least one layer of annular cavities.

[0013] Preferably, the tube body of the first connecting member is provided with a second cavity set between the opening groove and the external pipeline.

[0014] Preferably, the second cavity set is composed of a plurality of circumferentially distributed cavities, each cavity is provided with a vibration-damping sphere, and both ends of the vibration-damping sphere are fixedly connected to the inner wall of the cavity through a vibration-damping spring.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] 1. Through structural design, the sealing surface inside the pipe joint has a good self-locking function, thereby improving the sealing performance of the sealing surface; and the self-locking function will prevent the sealing performance from decreasing in complex environments such as vibration, thereby increasing its service life. Among them, the self-locking function is realized as follows: after the compression screw sleeve is installed, the outer surface of the butt end of the second connector squeezes the inner surface of the butt end of the first connector to form an axial pressure; the axial pressure presses the conical surface or spherical surface of the inner surface of the first connector, so that it exerts an upward force on the butt end of the first connector; due to the design of the variable diameter surface and the open groove, the butt end of the first connector forms a micro-deformation upward, thereby generating a reverse elastic force, which reacts on the sealing surfaces of the first connector and the second connector to form a reverse self-locking pressure, that is, to achieve the connection effect of preventing loosening and improving sealing performance. Based on the above principle, the design of the first cavity set is conducive to the elastic deformation of the butt end of the first connector, and the circumferentially evenly distributed cavities or annular cavities cooperate with the open grooves to achieve a more ideal self-locking effect. The structural deepening of the annular groove and the structural design of the elastic metal ring increase the reverse elastic force of the butt joint end of the first connecting piece that undergoes micro-deformation, thereby greatly improving the self-locking effect.

[0017] 2. The structural design of the second cavity set and the internal vibration-damping sphere can greatly reduce the impact of external vibration on the entire pipe joint. First, the circumferentially evenly distributed cavities in the second cavity set improve the original entity of the first connecting piece into a frame-like structure in terms of overall structure, reducing the impact of vibration; second, when the vibration is transmitted to the first connecting piece, the vibration after entering the cavity passes through different media, consuming part of the vibration; third, the vibration causes the vibration-damping sphere to overcome the elastic force at both ends and generate movement, consuming part of the vibration. In the above manner, most of the energy brought by the vibration can be consumed, thereby reducing the impact of the vibration on the pipe joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the overall structure of Example 1;

[0019] Figure 2 This is the enlarged view of point A;

[0020] Figure 3 It is the force conduction diagram;

[0021] Figure 4 This is a schematic diagram of the overall structure of Example 2;

[0022] Figure 5 A cross-sectional structural diagram of a first cavity set of circumferentially distributed cavities;

[0023] Figure 6 is a cross-sectional structural diagram of a first cavity set of annular cavities;

[0024] Figure 7 This is the overall structure diagram of Example 3;

[0025] Figure 8 This is a planar structural diagram of the interior of the cavity of the second cavity set.

[0026] In the figure: 1, first connecting member; 11, clamping table; 12, open groove; 13, elastic metal ring; 14, first cavity set; 15, second cavity set; 151, vibration-damping sphere; 152, vibration-damping spring; 2, second connecting member; 21, external thread; 3, tightening screw sleeve. DETAILED DESCRIPTION

[0027] The structure and principle of the present invention are now fully described in conjunction with specific embodiments so that those skilled in the art can fully understand and implement them.

[0028] Example 1

[0029] like Figure 1 As shown, a self-locking pipe joint comprises a first connector 1 with a pipeline channel in the middle, a second connector 2 and a compression screw sleeve 3; the outer ends of the first connector 1 and the second connector 2 are respectively fixedly connected to the pipelines on both sides by welding, and the inner ends are butted against each other; the outer surface of the first connector 1 is provided with a clamping platform 11, and the outer surface of the second connector 2 is provided with an external thread 21, one end of the compression screw sleeve 3 is threadedly sleeved on the second connector 2, and the other end abuts against the clamping platform 11; the first connector 1 and the second connector 2 are butted, fixed or disassembled by screwing the compression screw sleeve 3 in or out. In order to facilitate the screwing in or out of the compression screw sleeve 3 and avoid affecting the external pipelines on both sides, the first connector 1 and the second connector 2 can be designed as a structure with a gradually changing outer diameter near one end of the external pipeline, such as Figure 1 The left side of the first connecting member 1 and the external pipeline connection end are an outer cone-shaped changing structure, and the right side of the second connecting member 2 and the external pipeline connection end are a stepped changing structure.

[0030] Among them, the outer diameter of the first connecting member 1 on the side close to the butt end gradually decreases along the butt direction to form a variable diameter surface (M in the figure), and an annular open groove 12 is provided in the middle of the variable diameter surface; the cross-section of the open groove 12 is V-shaped; the variable diameter surface is a conical surface, that is, the longitudinal section of the variable diameter surface is an oblique line at a certain angle to the pipeline axis; the inner surface of the butt end of the first connecting member 1 is a conical surface; the outer surface of the butt end of the second connecting member 2 is a spherical surface; a spherical-conical seal is formed by the outer surface of the butt end of the second connecting member 2 contacting the inner surface of the butt end of the first connecting member 1.

[0031] like Figure 2 As shown, it is further provided that the upper part of the groove wall of the opening groove 12 is vertically recessed toward both sides to form an annular groove, and an elastic metal ring 13 matching its shape is provided in the annular groove.

[0032] In this embodiment, after the first connector 1 and the second connector 2 are fixedly connected to the external pipeline respectively, the first connector 1 and the second connector 2 are butted and pressed and fixed by the compression screw sleeve 3 to achieve the pipeline connection on both sides. Among them, the butt joint method of the first connector 1 and the second connector 2 is to fit and squeeze the spherical surface and the conical surface, and the squeezing force is provided by screwing the compression screw sleeve 3, so the external thread 21 is a high torque thread. Figure 3 As shown, the force F generated between the threads when screwing in is transmitted to the butt joint surface of the first connecting member 1 and the second connecting member 2, and the second connecting member 2 generates a pressure f1 on the conical surface of the first connecting member 1. Due to the structural design of the opening groove 12 and the diameter-changing surface M, the butt joint end of the first connecting member 1 will be slightly deformed with the opening groove 12 as the deformation origin when subjected to the pressure of f1; taking the axial direction perpendicular to the opening groove 12 as a component force decomposition direction, f1 is decomposed into an upward component force f2 generated by the conical surface and a component force f3 perpendicular to the axis of the opening groove 12, so that the side of the first connecting member 1 close to the butt joint end is slightly deformed upward under the action of the component force f2, that is, elastic deformation occurs (since the f3 component force is perpendicular to the axis of the deformation origin, its torque is 0, and it will not overcome the material stiffness to cause compression deformation of the butt joint end), and the elastic force of the elastic deformation reacts on the butt joint surface of the butt joint end of the second connecting member 2 to form a reverse pressing force, thereby achieving a self-locking and anti-loosening effect of the sealing surface. Among them, the addition of the elastic metal ring 13 can, on the one hand, make up for the structural defects of the opening groove 12 and avoid cracks that may occur due to long-term stress. On the other hand, it can provide additional elastic force when the first connecting member 1 produces micro-deformation near the butt end, thereby improving the self-locking force.

[0033] In order to facilitate screwing in or removing the compression screw sleeve 3, the cross section of the outer surface of the compression screw sleeve 3 is a regular hexagon.

[0034] From the above analysis, it can be known that if a self-locking elastic force based on the variable diameter surface M and the open groove 12 is to be generated, an angle difference must be generated on the contact surface of the first connector 1 and the second connector 2 to generate an upward force component on the butt end, that is, the conical surface and the spherical surface in this embodiment match. Therefore, in a preferred embodiment, the inner surface of the butt end of the first connector 1 can be any one of a conical surface, a spherical surface, or an arcuate surface, including an eccentric spherical surface or an eccentric conical surface; the outer surface of the butt end of the second connector 2 can be any one of a conical surface, a spherical surface, or an arcuate surface, including an eccentric spherical surface or an eccentric conical surface; to achieve an extrusion sealing effect of different structures. Among them, the sealing effect is better when the inner surface of the butt end of the first connector 1 is a conical surface and the outer surface of the butt end of the second connector 2 is matched with the eccentric spherical surface, which is more convenient for the sealing structure on both sides to fit each other. In addition, the size of the angle θ between the cross-sectional oblique line of the variable diameter surface M and the horizontal plane is crucial, which directly determines the torque of the component force f2. If the angle is too large, the torque will be reduced, elastic deformation will be difficult, and even micro-deformation will be difficult to produce. If it is too small and tends to 0°, the elastic force directly presses the compression screw sleeve 3, making it difficult to produce elastic deformation. After many mathematical statistics and experiments, the best angle of θ is 4-6°.

[0035] Example 2

[0036] This embodiment is designed as follows based on the embodiment 1: Figure 4 As shown, the tube body of the first connector 1 is provided with a first cavity set 14 between the opening groove 12 and the butt end. The first cavity set 14 may be composed of a plurality of cavities distributed in the circumferential direction, such as Figure 5 The four cavities shown in the figure can also be at least one layer of annular cavities, such as Figure 6 Shown is a single-layer annular cavity.

[0037] The design of the first cavity set 14 can reduce the rigidity of the butt end of the first connector 1, making it easier for the first connector 1 to produce elastic deformation near the butt end, further improving the self-locking force and the anti-loosening sealing effect.

[0038] Example 3

[0039] This embodiment makes the following improvements on the basis of the embodiment 1: the tube body of the first connecting member 1 is provided with a second cavity set 15 between the opening groove 12 and the external pipeline; wherein: Figure 7 As shown, the second cavity set 15 is composed of four cavities distributed circumferentially; Figure 8 As shown, a vibration-damping sphere 151 is provided in each cavity, and two ends of the vibration-damping sphere 151 are fixedly connected to the inner wall of the cavity through vibration-damping springs 152 .

[0040] The second cavity set 15 is designed on the pipe body between the opening groove 12 and the external pipeline to reduce the influence of external vibration on the pipe joint. For example, when the external oil circuit enters the pipe joint or the joint vibrates, the self-locking effect and sealing of the joint between the first connecting member 1 and the second connecting member 2 are further improved while reducing the influence of vibration.

[0041] The vibration reduction methods are as follows: 1. Through the structural design of the cavity, a cavity frame is formed inside the first connecting member 1. When the vibration passes through the cavity, part of the vibration wave energy is consumed due to the change in the medium; 2. Through the structural design of the vibration-damping sphere 151 and the vibration-damping spring 152, when the vibration wave is transmitted to the cavity, the vibration-damping sphere 151 overcomes the restraint of the vibration-damping spring 152 by consuming the vibration energy, generates micro-elastic movement, and quickly consumes the vibration wave energy.

[0042] The above embodiments are only preferred embodiments of the present invention and are not any formal limitations on the present invention. Any technician familiar with the art can use the above disclosed methods to make many possible changes and modifications to the technical solution of the present invention without departing from the technical principle and solution scope of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any combination, modification or replacement of the technical features disclosed in the present invention based on the technical essence of the present invention without departing from the principle or solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A self-locking pipe joint, comprising a first connecting piece (1) with a pipeline passage in the middle, a second connecting piece (2) and a compression screw sleeve (3); the outer ends of the first connecting piece (1) and the second connecting piece (2) are respectively fixedly connected to the pipelines on both sides, and the inner ends are butted against each other; characterized in that: The outer surface of the first connecting member (1) is provided with a clamping platform (11), the outer surface of the second connecting member (2) is provided with an external thread (21), one end of the compression screw sleeve (3) is sleeved on the second connecting member (2) through a thread, and the other end abuts against the clamping platform (11); the outer diameter of the first connecting member (1) on the side close to the butt end gradually decreases along the butt direction to form a diameter-changing surface, and an annular opening groove (12) is provided in the middle of the diameter-changing surface; the cross section of the opening groove (12) is V-shaped, and the upper part of the groove wall of the opening groove (12) is vertically recessed on both sides to form an annular clamping groove, and the annular clamping groove An elastic metal ring (13) having a shape matching that of the first connecting piece (1) is provided inside; the inner surface of the butt end of the first connecting piece (1) is a conical surface or a spherical surface; the outer surface of the butt end of the second connecting piece (2) is a conical surface or a spherical surface; a conical surface seal or a spherical surface seal or a ball-cone seal is formed by the outer surface of the butt end of the second connecting piece (2) abutting against the inner surface of the butt end of the first connecting piece (1), and under the axial pressure of the compression screw sleeve (3), the open groove (12) and the elastic metal ring (13) cooperate to cause the butt end of the first connecting piece (1) to generate elastic deformation to form a self-locking pressure.

2. A self-locking pipe joint according to claim 1, characterized in that: The diameter-changing surface is a conical surface or an arc-shaped curved surface.

3. A self-locking pipe joint according to claim 1, characterized in that: The tube body of the first connecting member (1) is provided with a first cavity set (14) between the opening groove (12) and the butt end.

4. A self-locking pipe joint as claimed in claim 3, characterized in that: The first cavity set (14) consists of a plurality of cavities distributed in the circumferential direction.

5. A self-locking pipe joint as claimed in claim 3, characterized in that: The first cavity set (14) is at least one layer of annular cavities.

6. A self-locking pipe joint according to claim 1, characterized in that: The tube body of the first connecting piece (1) is provided with a second cavity set (15) between the opening groove (12) and the external pipeline.

7. A self-locking pipe joint according to claim 6, characterized in that: The second cavity set (15) is composed of a plurality of circumferentially distributed cavities, each cavity being provided with a vibration-damping sphere (151), and both ends of the vibration-damping sphere (151) are fixedly connected to the inner wall of the cavity via vibration-damping springs (152).

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