A composite compression fitting

Abstract

This utility model belongs to the field of pipe fitting technology, specifically relating to a composite ferrule pipe fitting, including a composite ferrule, comprising a ferrule body and a sealing ring. The ferrule body includes a sealing section, a base section, and a tail section along the axial direction. The fitting body has a tapered end with an inner circumferential surface including an outer ring surface and an inner ring surface. A compression nut is rotatably fitted onto the tail section. This utility model forms a rigid seal by the cooperation of the second conical surface of the sealing section with the inner ring surface of the fitting body. The sealing ring is accommodated by an annular cavity formed by the outer circumferential surface exposed at the pipe end, the first conical surface, and the inner ring surface, and is deformed under pressure. This effectively fills all microscopic gaps caused by machining tolerances, thus forming a flexible seal. The two work together to greatly improve the reliability and safety of the seal, ensuring absolute airtightness even under pressure fluctuations or slight vibrations, completely solving the problem of air leakage.

Description

Technical Field

[0001] This utility model belongs to the field of pipe fitting connection technology, specifically relating to a composite compression fitting pipe joint. Background Technology

[0002] In the air braking system of commercial vehicles, due to the long installation distance between the air pump and the dryer, the complex spatial layout, and the constraints of the overall vehicle layout and shape requirements, it is not possible to use a single steel pipe for connection; therefore, the connection between steel pipes is generally achieved through compression fittings.

[0003] Compression fittings mainly consist of three parts: the fitting body, the ferrule, and the clamping nut. During assembly, the clamping nut is first inserted into the steel pipe, then the ferrule is riveted to the end of the steel pipe using special equipment. Next, the steel pipe is inserted into the fitting body, and finally, the clamping nut is tightened to make the outer conical surface of the ferrule's front end fit tightly against the inner conical surface of the fitting body, thereby achieving a seal through the interference fit between the metal surfaces.

[0004] However, since both the ferrule and the steel pipe are metal parts, their production and machining inevitably involve dimensional tolerances, resulting in a small gap between the mating surfaces of the ferrule and the steel pipe after the ferrule is riveted onto the steel pipe. In addition, the tapered fit between the ferrule and the connector body is also difficult to achieve a perfect fit due to machining accuracy issues, resulting in a gap. The gap between the aforementioned metal parts is the main reason for the chronic gas leakage at the ferrule connector position in the air braking system.

[0005] The presence of such gaps makes it easy for compressed air to leak from the joints when it flows in the pipeline, which not only reduces system pressure and affects braking performance, but may also increase maintenance costs and the risk of failure. Utility Model Content

[0006] The purpose of this invention is to provide a composite compression fitting that solves the technical problem of air leakage caused by the gap between metal parts due to machining tolerances in the prior art.

[0007] This utility model discloses a composite card sleeve, comprising:

[0008] A composite ferrule is fixedly fitted onto the end of a tube body, partially exposing the outer circumferential surface of the tube body end. The composite ferrule includes a ferrule body and a sealing ring. The ferrule body comprises, along the axial direction, a sealing section, a base section, and a tail section. The outer circumferential surface of the sealing section includes a first conical surface and a second conical surface connected together. The first conical surface is located at the front end of the ferrule body, and its cone angle is greater than that of the second conical surface. The sealing ring is located at the end of the sealing section away from the base section.

[0009] The connector body has a tapered opening at its connecting end. The inner circumferential surface of the tapered opening includes a connected outer ring surface and an inner ring surface. The bottom wall of the tapered opening abuts against the end face of the tube body. The outer ring surface mates with the outer circumferential surface of the base section. The inner ring surface mates with the second conical surface.

[0010] Tighten the nut, rotate it onto the tail section, and thread it to the connecting end of the connector body;

[0011] The outer peripheral surface exposed at the end of the tube, the first conical surface, and the inner annular surface together form an annular cavity with an approximately triangular cross-section, and the sealing ring is accommodated within the annular cavity.

[0012] This application achieves a rigid seal by engaging the second conical surface of the sealing section with the inner annular surface of the connector body. The sealing ring is then accommodated by an annular cavity formed by the exposed outer circumferential surface of the pipe end, the first conical surface, and the inner annular surface, which deforms under pressure. This effectively fills all microscopic gaps caused by machining tolerances, thus forming a flexible seal. The combination of these two elements greatly enhances the reliability and safety of the seal, ensuring absolute airtightness even under pressure fluctuations or slight vibrations, completely solving the problem of air leakage.

[0013] Based on the above technical solution, the solution of this application can be further improved as follows:

[0014] Preferably, the end face of the sealing section is provided with an annular groove, and the sealing ring fills the annular groove; this solution provides a larger attachment area for the sealing ring and forms a physical limiting structure, thereby significantly improving the fixing effect of the sealing ring.

[0015] Preferably, the outer peripheral surface of the base segment is a third conical surface connected to the second conical surface, and its cone angle is smaller than that of the second conical surface. By adopting this solution, the concentrated stress generated by locking can be efficiently dispersed, thereby optimizing the stress distribution, avoiding local pressure loss, and enabling the base segment to be firmly attached to the joint body, thereby greatly enhancing the mechanical stability of the joint in terms of vibration resistance, impact resistance, and prevention of loosening.

[0016] Preferably, the sealing ring is a continuous integral structure and covers the end face of the sealing section away from the base section, part of the first conical surface, and part of the inner circumferential surface of the sealing section. By adopting this solution, leakage problems in multiple directions are solved simultaneously with one part, which reduces structural complexity and production costs while ensuring sealing effect.

[0017] Preferably, the wide end of the clamping nut is threaded to the connecting end of the connector body, and the narrow end is adapted to the pipe diameter of the pipe body. This solution can significantly suppress the swaying or shaking of the pipe body under high-frequency vibration, and enhance the vibration resistance and bending stress resistance of the entire connector.

[0018] Preferably, the wide end of the clamping nut is provided with an internal thread, and the connecting end of the connector body is provided with an external thread, with the internal thread and the external thread engaging; this solution improves the stability of the threaded connection.

[0019] Preferably, the inner circumferential surface of the clamping nut includes a connected cylindrical surface and a fourth conical surface; the fourth conical surface is located at the end of the clamping nut away from the connector body, and its diameter gradually decreases in the direction away from the connector body;

[0020] The cylindrical surface mates with the outer circumferential surface of the tail section, and the fourth conical surface mates with the rear end face of the tail section. This design ensures that the clamping nut can rotate smoothly and transmit uniform axial clamping force, and can also convert part of the axial force into radial contraction force, making the clamping effect of the composite ferrule 1 more uniform and reliable. It also greatly enhances the anti-loosening ability of the joint under vibration conditions and improves the stability of the overall connection.

[0021] Through the above technical solution, this utility model achieves the following beneficial effects:

[0022] 1. This application forms a rigid seal by mating the second conical surface of the sealing section with the inner ring surface of the connector body. Then, the sealing ring is accommodated by the annular cavity formed by the outer circumferential surface exposed at the end of the pipe, the first conical surface, and the inner ring surface, and is deformed under pressure. This effectively fills all the micro gaps caused by the machining tolerance, thus forming a flexible seal. The two work together to greatly improve the reliability and safety of the seal. Even under pressure fluctuations or slight vibrations, absolute airtightness can be guaranteed, completely solving the problem of air leakage.

[0023] 2. This application provides a larger attachment area for the sealing ring through the annular groove and forms a physical limiting structure, thereby significantly improving the fixing effect of the sealing ring. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the composite compression fitting described in a specific embodiment of this application;

[0026] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0027] Figure 3 for Figure 1 The diagram shows the structure of the composite ferrule in the composite ferrule fitting.

[0028] Figure 4 for Figure 3 Enlarged view of point B in the middle;

[0029] Figure 5 for Figure 1 The diagram shows the structure of the connector body in the composite compression fitting.

[0030] Figure 6 for Figure 1 The diagram shows the structure of the clamping nut in the composite ferrule fitting.

[0031] Explanation of reference numerals in the attached figures:

[0032] 100. Pipe body;

[0033] 1. Composite ferrule; 11. Ferrule body; 111. Sealing section; 1111. First conical surface; 1112. Second conical surface; 1113. Annular groove; 112. Base section; 1121. Third conical surface; 113. Tail section; 12. Sealing ring;

[0034] 2. Connector body; 21. Tapered opening; 211. Outer annular surface; 212. Inner annular surface; 22. External thread;

[0035] 3. Tightening nut; 31. Internal thread; 32. Cylindrical surface; 33. Fourth conical surface. Detailed Implementation

[0036] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0037] The terms “first”, “second”, etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as “first” or “second” may explicitly or implicitly include one or more of the stated features.

[0038] In this application, unless otherwise expressly specified and limited, the terms "installation" and "connection" 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 direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0039] To better understand the above technical solutions, the following will provide a detailed description of the technical solutions in conjunction with the accompanying drawings and specific embodiments.

[0040] Example:

[0041] like Figure 1 As shown in the figure, this application discloses a composite ferrule pipe fitting for connecting pipe bodies 100, which has the advantage of good sealing performance and avoids the risk of leakage. Its specific structure includes: composite ferrule 1, fitting body 2 and clamping nut 3.

[0042] like Figure 2 and Figure 3 As shown, the composite ferrule 1 is fixedly sleeved on the end of the tube body 100 and partially exposed on the outer circumferential surface of the end of the tube body 100. It consists of two parts: the ferrule body 11 and the sealing ring 12.

[0043] The ferrule body 11 is made of metal and provides structural strength and main sealing path; it includes a sealing section 111, a base section 112 and a tail section 113 in sequence along the axial direction; the outer peripheral surface of the sealing section 111 includes a first conical surface 1111 and a second conical surface 1112 connected together, the first conical surface 1111 is located at the front end of the ferrule body 11 and its cone angle is greater than the cone angle of the second conical surface 1112.

[0044] Specifically, the sealing section 111 serves as a guide and positioning element. When inserted into the tapered opening 21 of the connector body 2, its conical surface facilitates alignment. The base section 112 mainly provides support and stability. Its outer surface mates with the outer ring surface 211 of the connector body 2, allowing it to withstand significant radial forces. The tail section 113 is used to bear and transmit torque, converting the torque into the axial forward and tightening forces of the composite ferrule 1.

[0045] Preferably, such as Figure 2 As shown, the inner circumferential surface of the sleeve body 11 has annular protrusions, which can engage with the outer circumferential surface of the tube body 100, thereby ensuring a stable connection and playing a certain role in sealing and isolation.

[0046] like Figure 3As shown, the sealing ring 12 is located at the end of the sealing section 111 away from the base section 112, and it is made of vulcanized or injection-molded polymer materials (such as rubber, polyurethane, etc.) or sintered soft metal.

[0047] like Figure 5 As shown, the connector body 2 is a fixed part in the connection circuit. Its connection end has a tapered opening 21. The tapered opening 21 is used for axial insertion of the tube body 100 with the composite sleeve 1 at the end. The inner circumferential surface of the tapered opening 21 includes an outer ring surface 211 and an inner ring surface 212 connected together.

[0048] Specifically, such as Figure 2 As shown, the bottom wall of the tapered opening 21 abuts against the end face of the tube body 100, which serves as an axial stop and improves the sealing effect through surface contact; the outer ring surface 211 mates with the outer circumferential surface of the base section 112, mainly serving as a guide and radial support to ensure that the composite ferrule 1 can move and be pressed along the correct axis; the inner ring surface 212 mates with the second conical surface 1112 to form the main metal-metal sealing pair.

[0049] like Figure 1 As shown, the clamping nut 3 is rotatably sleeved on the outer side of the tail section 113 and threadedly connected to the connecting end of the connector body 2. It is used to generate axial tension force by tightening the threaded connection with the connector body 2, pushing the entire composite ferrule 1 into the tapered opening 21, thereby completing the tight fit between the second conical surface 1112 and the inner ring surface 212 and the compression of the sealing ring 12.

[0050] The outer peripheral surface exposed at the end of the tube 100, the first conical surface 1111, and the inner annular surface 212 together form an annular cavity with an approximately triangular cross-section, and the sealing ring 12 is accommodated within the annular cavity.

[0051] It should be noted that, since the cone angle of the first conical surface 1111 is greater than that of the second conical surface 1112, when the second conical surface 1112 and the inner ring surface 212 are tightly fitted to form a sealing pair, the first conical surface 1111 does not contact the inner ring surface 212. Therefore, it can together with the outer peripheral surface exposed at the end of the tube body 100 and the inner ring surface 212 to form the above-mentioned annular cavity, thereby providing installation and deformation space for the sealing ring 12.

[0052] When the compression nut 3 is tightened, it will push the entire composite ferrule 1 into the tapered opening 21 of the connector body 2. As a result, the annular cavity will become smaller, causing the sealing ring 12 to be compressed radially and axially and deformed. This will completely fill all the microscopic gaps between the front end of the sealing section 111 and the pipe body 100 and the connector body 2, thus forming a second airtight seal.

[0053] This invention forms a rigid seal by cooperating the second conical surface 1112 of the sealing section 111 with the inner ring surface 212 of the connector body 2. The sealing ring 12 is accommodated by the annular cavity formed by the outer peripheral surface exposed at the end of the pipe body 100, the first conical surface 1111, and the inner ring surface 212, and is deformed under pressure. This effectively fills all the micro gaps caused by the machining tolerance, thus forming a flexible seal. The two work together to greatly improve the reliability and safety of the seal. Even under pressure fluctuations or slight vibrations, it can ensure absolute airtightness and completely solve the problem of air leakage.

[0054] In some embodiments, such as Figure 4 As shown, an annular groove 1113 is provided on the end face of the sealing section 111, and the sealing ring 12 fills the annular groove 1113.

[0055] By designing the annular groove 1113, a larger attachment area is provided for the sealing ring 12, and a physical limiting structure is formed, thereby significantly improving the fixing effect of the sealing ring 12.

[0056] In some embodiments, such as Figure 3 As shown, the outer peripheral surface of the base segment 112 is a third conical surface 1121 connected to the second conical surface 1112, and its cone angle is smaller than that of the second conical surface 1112.

[0057] Through the above design, a large area of ​​surface contact can be formed with the outer ring surface 211, thereby efficiently dispersing the concentrated stress generated by locking, thus optimizing the stress distribution, avoiding local pressure loss, and effectively converting the axial locking force into radial support force, so that the base segment 112 can be firmly attached to the joint body 2 and jointly bear the radial load inside the system, thereby greatly enhancing the mechanical stability of the joint in terms of vibration resistance, impact resistance and preventing loosening.

[0058] In some embodiments, such as Figure 4 As shown, the sealing ring 12 is a continuous integral structure and covers the end face of the sealing section 111 away from the base section 112, part of the first conical surface 1111, and part of the inner circumferential surface of the sealing section 111.

[0059] The above design enhances the fixing strength of the sealing ring 12, effectively preventing displacement or detachment. It also forms elastic sealing layers on both the inner and outer sides of the front end of the ferrule body 11, thus solving leakage problems in multiple directions with a single component. This ensures sealing performance while reducing structural complexity and production costs.

[0060] In some embodiments, such as Figure 1 As shown, the wide end of the clamping nut 3 is threaded to the connecting end of the connector body 2, and the narrow end is adapted to the diameter of the pipe body 100.

[0061] Through the above design, the clamping nut 3 can provide additional radial constraint to the pipe body 100 after being locked, which can significantly suppress the swaying or shaking of the pipe body 100 under high frequency vibration, and enhance the vibration resistance and bending stress resistance of the entire joint.

[0062] Based on the above embodiments, such as Figure 5 and Figure 6 As shown, the wide end of the clamping nut 3 is provided with an internal thread 31, and the connecting end of the connector body 2 is provided with an external thread 22. The internal thread 31 and the external thread 22 cooperate to improve the stability of the threaded connection.

[0063] In some embodiments, such as Figure 1 and Figure 6 As shown, the inner circumferential surface of the clamping nut 3 includes a connected cylindrical surface 32 and a fourth conical surface 33; the fourth conical surface 33 is located at the end of the clamping nut 3 away from the connector body 2, and its diameter gradually decreases in the direction away from the connector body 2.

[0064] The cylindrical surface 32 mates with the outer circumferential surface of the tail section 113, thereby ensuring that the clamping nut 3 can be accurately fitted onto the tail section 113 and move smoothly along the axis of the composite ferrule 1 during tightening, preventing the clamping nut 3 from jamming or damaging the threads due to misalignment, and ensuring smooth installation and alignment; the fourth conical surface 33 mates with the rear end face of the tail section 113, thereby efficiently converting the axial tension of the clamping nut 3 into propulsive force and radial locking force, thus significantly improving the joint's vibration resistance and anti-loosening ability.

[0065] Through the above design, it is ensured that the clamping nut 3 can rotate smoothly and transmit uniform axial clamping force. It also forms a wedge-shaped locking structure, which can convert part of the axial force into radial contraction force, making the clamping effect of the composite ferrule 1 more uniform and reliable. It also greatly enhances the anti-loosening ability of the joint under vibration conditions and improves the overall stability of the connection.

[0066] Numerous specific details are set forth in this specification. However, it will be understood that embodiments of this invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0067] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. A composite compression fitting, characterized in that, include: A composite ferrule is fixedly fitted onto the end of a tube body, partially exposing the outer circumferential surface of the tube body end. The composite ferrule includes a ferrule body and a sealing ring. The ferrule body comprises, along the axial direction, a sealing section, a base section, and a tail section. The outer circumferential surface of the sealing section includes a first conical surface and a second conical surface connected together. The first conical surface is located at the front end of the ferrule body, and its cone angle is greater than that of the second conical surface. The sealing ring is located at the end of the sealing section away from the base section. The connector body has a tapered opening at its connecting end. The inner circumferential surface of the tapered opening includes a connected outer ring surface and an inner ring surface. The bottom wall of the tapered opening abuts against the end face of the tube body. The outer ring surface mates with the outer circumferential surface of the base section. The inner ring surface mates with the second conical surface. Tighten the nut, rotate it onto the tail section, and thread it to the connecting end of the connector body; The outer peripheral surface exposed at the end of the tube, the first conical surface, and the inner annular surface together form an annular cavity with an approximately triangular cross-section, and the sealing ring is accommodated within the annular cavity.

2. The composite compression fitting according to claim 1, characterized in that, The end face of the sealing section is provided with an annular groove, and the sealing ring fills the annular groove.

3. The composite compression fitting according to claim 1, characterized in that, The outer peripheral surface of the base segment is a third conical surface connected to the second conical surface, and its cone angle is smaller than that of the second conical surface.

4. The composite compression fitting according to claim 1, characterized in that, The sealing ring is a continuous integral structure and covers the end face of the sealing section away from the base section, part of the first conical surface, and part of the inner circumferential surface of the sealing section.

5. The composite compression fitting according to claim 1, characterized in that, The wide end of the clamping nut is threaded to the connecting end of the connector body, and the narrow end is adapted to the diameter of the pipe body.

6. The composite compression fitting according to claim 5, characterized in that, The wide end of the clamping nut is provided with an internal thread, and the connecting end of the connector body is provided with an external thread, and the internal thread and the external thread are engaged.

7. The composite compression fitting according to claim 1, characterized in that, The inner circumferential surface of the clamping nut includes a connected cylindrical surface and a fourth conical surface; the fourth conical surface is located at the end of the clamping nut away from the connector body, and its diameter gradually decreases in the direction away from the connector body. The cylindrical surface mates with the outer peripheral surface of the tail section, and the fourth conical surface mates with the rear end surface of the tail section.

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