Seamless welding support device for PFA (Polyfluoroalkoxy) pipe

Abstract

The invention belongs to the technical field of seamless welding of PFA pipes, and particularly relates to a seamless welding supporting device for a PFA pipe. The seamless welding supporting device for the PFA pipe comprises an air bag, the axial tensioning assembly is arranged in the air bag; wherein the two ends of the axial tensioning assembly are fixedly connected with the two ends of the air bag. According to the seamless welding supporting device for the PFA pipe, the axial tensioning assembly is arranged in the air bag, axial expansion of the air bag is limited, and the situations of pipe deformation, size inconsistency and the like are reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of seamless welding of PFA tubes, and particularly relates to a seamless welding support device for PFA tubes. Background Art

[0002] During the seamless welding process of PFA tubes, the PFA tubes will collapse inward when heated, resulting in insufficient roundness of the welded part, and the contact pressure during welding is also uneven. Therefore, during the seamless welding of PFA tubes, internal support needs to be provided through an airbag inside the tube. Specifically, during welding, the ends of two tubes to be welded are aligned inside the heating device first, and then the airbag is inserted into the tube to form an internal support, so as to cooperate with the inner wall of the heating device to restrict the radial deformation of the tube. Finally, the welding part is heated by the heating device for welding. In this way, the welded part of the welded PFA tube has no fusion marks or weld beads.

[0003] Restricted by the inner wall of the PFA pipe material, the traditional airbag will expand axially (i.e., along the length direction of the pipe material) during the inflation process, and the thermal collapse of the PFA pipe will also squeeze the airbag to cause its axial expansion, resulting in insufficient radial support force provided by the airbag or uneven radial support, thus leading to inconsistent dimensions of the welded pipe material, deformation of the pipe material, etc. Summary of the Invention

[0004] The purpose of the present invention is to provide a seamless welding support device for PFA tubes to solve the technical problem of poor welding quality caused by axial expansion during the inflation of the existing airbag.

[0005] The present application provides a seamless welding support device for PFA tubes. The seamless welding support device for PFA tubes includes:

[0006] An airbag;

[0007] An axial tensioning assembly disposed inside the airbag; wherein

[0008] Both ends of the axial tensioning assembly are fixedly connected to both ends of the airbag.

[0009] In an embodiment of the present application, the airbag includes a head and a tail at both ends, and a working part in the middle;

[0010] A nozzle joint is provided inside the head;

[0011] One end of the axial tensioning assembly is fixed inside the nozzle joint, and the other end is fixed to the tail of the airbag.

[0012] In an embodiment of the present application, one end of the nozzle joint is located outside the airbag for connecting to a nozzle;

[0013] The other end of the nozzle joint is located inside the airbag for fixing the axial tensioning assembly.

[0014] In one embodiment of the present application, an air passage is provided inside the nozzle joint, and a stepped portion is provided on the inner wall of the end of the air passage located inside the airbag;

[0015] The axial tensioning assembly includes a tensioning member and a fixing ring located at the front end of the tensioning member;

[0016] The tensioning member is disposed through the air passage, and the fixing ring is clamped inside the stepped portion.

[0017] In one embodiment of the present application, a first annular groove is provided on the outer periphery of the nozzle joint;

[0018] An annular protrusion for being snapped into the first annular groove is provided on the inner wall of the head of the airbag.

[0019] In one embodiment of the present application, a front end cover is sleeved on the outer periphery of the head of the airbag;

[0020] A second annular groove is provided on the outer periphery of the nozzle joint;

[0021] The front end of the front end cover is snap-fitted into the second annular groove.

[0022] In one embodiment of the present application, a rear end cover is sleeved on the outer periphery of the tail of the airbag;

[0023] The axial tensioning assembly includes a tensioning member and a fixing column located at the rear end of the tensioning member;

[0024] One end of the fixing column is fixedly connected to the tensioning member, and the other end passes through the tail of the airbag and the exposed part is fixedly connected to the rear end cover.

[0025] In one embodiment of the present application, the fixing column is in threaded fit with the rear end cover.

[0026] In one embodiment of the present application, a diameter-expanded portion is provided on the part of the fixing column located inside the tail of the airbag.

[0027] In one embodiment of the present application, a plurality of reinforcing ribs are provided on the inside of the working portion.

[0028] The beneficial effects of the present invention are:

[0029] Different from the prior art, the present application provides a seamless welding support device for a PFA tube. The seamless welding support device for a PFA tube includes: an airbag; an axial tensioning assembly disposed inside the airbag; wherein both ends of the axial tensioning assembly are fixedly connected to both ends of the airbag. By providing the axial tensioning assembly inside the airbag, the seamless welding support device for a PFA tube of the present invention restricts the axial expansion of the airbag and reduces the occurrence of situations such as tube deformation and inconsistent dimensions.

[0030] Other features and advantages of the present invention will be set forth in the following description, and in part will be obvious from the description, or can be learned by practice of the present invention. The objectives and other advantages of the present invention are realized and attained by the structure particularly pointed out in the specification and the drawings.

[0031] To make the above objectives, features and advantages of the present invention more comprehensible, the following specific preferred embodiments are given, in conjunction with the accompanying drawings, and are described in detail as follows. Description of the Drawings

[0032] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0033] Figure 1 is a schematic diagram of a seamless welding support device for a PFA tube according to a preferred embodiment of the present invention;

[0034] Figure 2 is a cross-sectional view of a seamless welding support device for a PFA tube according to a preferred embodiment of the present invention;

[0035] Figure 3 is Figure 2 a partial enlarged view in;

[0036] Figure 4 is a cross-sectional view of an airbag according to a preferred embodiment of the present invention;

[0037] Figure 5 is a schematic diagram of an axial tensioning assembly according to a preferred embodiment of the present invention;

[0038] Figure 6 is a schematic diagram of a nozzle joint and a nozzle according to a preferred embodiment of the present invention.

[0039] In the figure:

[0040] airbag 1, head 11, annular protrusion 111, tail 12, working part 13, reinforcing rib 131, axial tensioning assembly 2, tensioning member 21, fixing ring 22, fixing column 23, diameter-expanding part 231, nozzle joint 3, air passage 31, stepped part 32, nozzle 4, first annular groove 33, second annular groove 34, front end cover 5, rear end cover 6. Detailed Embodiments

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0042] This application provides a seamless welding support device for a PFA tube, which will be described in detail below. It should be noted that the description order of the following embodiments does not limit the preferred order of the embodiments of this application. And in the following embodiments, each embodiment has its own emphasis. For parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0043] See Figure 1 and Figure 2 , in one embodiment, the seamless welding support device for a PFA tube includes: an airbag 1; an axial tensioning assembly 2 disposed inside the airbag 1; wherein both ends of the axial tensioning assembly 2 are fixedly connected to both ends of the airbag 1.

[0044] In this embodiment, by disposing the axial tensioning assembly 2 inside the airbag 1 to tension both ends of the airbag 1, axial expansion of the airbag 1 during inflation can be restricted.

[0045] See Figure 2 and Figure 3 , specifically, the airbag 1 includes heads 11 and tails 12 at both ends, and a working portion 13 in the middle; a nozzle joint 3 is disposed inside the head 11; one end of the axial tensioning assembly 2 is fixed inside the nozzle joint 3, and the other end is fixed to the tail 12 of the airbag 1.

[0046] See Figure 4 , in this embodiment, the heads 11 and tails 12 of the airbag 1 can be used to assemble other components, and the working portion 13 is the main expansion area of the airbag 1 for supporting the inner wall of the PFA tube to be welded. Optionally, a plurality of reinforcing ribs 131 are disposed inside the working portion 13, which can make the supporting force provided by the working portion 13 more stable.

[0047] Further, one end of the nozzle joint 3 is located outside the airbag 1 for connecting to a nozzle 4; the other end of the nozzle joint 3 is located inside the airbag 1 for fixing the axial tensioning assembly 2.

[0048] Optionally, the nozzle 4 can be a micro pagoda PT quick-connect fitting, which can be threadedly engaged with the nozzle joint 3.

[0049] As an alternative embodiment of the cooperation between the axial tensioning assembly 2 and the nozzle joint 3, seeFigure 2 , Figure 3 and Figure 5 , an air nozzle joint 3 is internally provided with an air passage 31, and a stepped portion 32 is provided on the inner wall of the end of the air passage 31 located inside the airbag 1; the axial tensioning assembly 2 includes a tensioning member 21 and a fixing ring 22 located at the front end of the tensioning member 21; the tensioning member 21 is inserted through the air passage 31, and the fixing ring 22 is clamped inside the stepped portion 32.

[0050] Optionally, during assembly, the tensioning member 21 can be first inserted into the air passage 31, and then the fixing ring 22 is fixed on the tensioning member 21. The tensioning member 21 is connected to the air nozzle joint 3 through the cooperation between the fixing ring 22 and the stepped portion 32. It can be understood that the cooperation between the fixing ring 22 and the stepped portion 32 is not a sealing cooperation, so the air passage 31 will not be blocked. When inflating, gas can enter the air passage 31 from the air nozzle 4 and then enter the airbag 1.

[0051] See Figure 3 and Figure 6 , as a fixing method for the air nozzle joint 3 and the head 11 of the airbag 1, a first annular groove 33 is provided on the outer periphery of the air nozzle joint 3; an annular protrusion 111 for being clamped into the first annular groove 33 is provided on the inner wall of the head 11 of the airbag 1. During installation, the air nozzle joint 3 can be inserted along the through hole of the head 11 until the annular protrusion 111 is clamped into the first annular groove 33, that is, the fixing of the air nozzle joint 3 and the head 11 of the airbag 1 is completed.

[0052] Further, a front end cover 5 is sleeved on the outer periphery of the head 11 of the airbag 1; a second annular groove 34 is provided on the outer periphery of the air nozzle joint 3; the front end of the front end cover 5 is clamped in the second annular groove 34. The front end cover 5 can be made of aluminum alloy, and sleeving it on the outer periphery of the head 11 can further tighten the fixed connection between the air nozzle joint 3 and the airbag 1.

[0053] Further, as a preferred fixing method for the axial tensioning assembly 2 and the tail 12 of the airbag 1, see Figure 2 and Figure 5 , a rear end cover 6 is sleeved on the outer periphery of the tail 12 of the airbag 1; the axial tensioning assembly 2 includes a tensioning member 21 and a fixing column 23 located at the rear end of the tensioning member 21; one end of the fixing column 23 is fixedly connected to the tensioning member 21, and the other end passes through the tail 12 of the airbag 1 and the exposed part is fixedly connected to the rear end cover 6.

[0054] Optionally, the fixing column 23 is in threaded cooperation with the rear end cover 6.

[0055] During assembly, the rear end of the fixing column 23 can be first passed out from the tail 12, and then the rear end cover 6 is gradually tightened on the rear end of the fixing column 23.

[0056] In this embodiment, referring to Figure 5 , preferably, a diameter-expanded portion 231 is provided on a part of the fixing post 23 located inside the tail portion 12 of the airbag 1. The outer periphery of the diameter-expanded portion 231 can be arc-shaped.

[0057] During the process of gradually screwing the rear end cover 6 onto the rear end of the fixing post 23, the diameter-expanded portion 231 is continuously inserted into the tail portion 12 of the airbag 1, so that the diameter-expanded portion 231 can effectively seal the tail portion 12.

[0058] In this embodiment, as an alternative embodiment of the axial tensioning assembly 2, the tensioning member 21 can be a steel wire rope, and the fixing ring 22 can be a metal ring, which is fixedly pressed at the front end of the tensioning member 21 by a hydraulic crimper; the front end of the fixing post 23 can be provided with an insertion groove for the rear end of the tensioning member 21 to be inserted. After the tensioning member 21 is inserted, it can also be fixedly pressed by a hydraulic crimper, so that the tensioning member 21 is connected to the fixing post 23.

[0059] It should be noted that each device (components without specific structures described) selected in this application is a general standard component or a component known to those skilled in the art, and its structure and principle can be known to those skilled in the art through technical manuals or obtained through conventional experimental methods.

[0060] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection.

[0061] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention 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 of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0062] Based on the above inspiration from the ideal embodiment of the present invention, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of the present invention. The technical scope of the present invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A PFA pipe seamless welding support device, characterized in that: include: Airbag (1); An axial tensioning assembly (2) is arranged inside the airbag (1); in The two ends of the axial tensioning assembly (2) are fixedly connected to the two ends of the airbag (1).

2. The PFA pipe seamless welding support device according to claim 1, characterized in that: The airbag (1) comprises a head portion (11) and a tail portion (12) located at two ends, and a working portion (13) located in the middle; A gas nozzle connector (3) is provided on the inner side of the head (11); One end of the axial tensioning assembly (2) is fixed in the air nozzle joint (3), and the other end is fixed to the tail (12) of the airbag (1).

3. The PFA pipe seamless welding support device according to claim 2, characterized in that: One end of the air nozzle connector (3) is located outside the air bag (1) and is used for connecting the air nozzle (4); The other end of the air nozzle connector (3) is located inside the air bag (1) and is used to fix the axial tensioning assembly (2).

4. The PFA pipe seamless welding support device according to claim 2, characterized in that: An air passage (31) is provided inside the air nozzle joint (3), and a step portion (32) is provided on the inner wall of the end of the air passage (31) located inside the air bag (1); The axial tensioning assembly (2) comprises a tensioning member (21) and a fixing ring (22) located at the front end of the tensioning member (21); The tensioning member (21) is inserted into the air passage (31), and the fixing ring (22) is clamped on the inner side of the step portion (32).

5. The PFA pipe seamless welding support device according to claim 4, characterized in that: The outer periphery of the gas nozzle joint (3) is provided with a first annular groove (33); An annular protrusion (111) for being inserted into the first annular groove (33) is provided on the inner wall of the head (11) of the airbag (1).

6. The PFA pipe seamless welding support device according to claim 4, characterized in that: The outer peripheral cover of the head portion (11) of the airbag (1) is provided with a front end cover (5); The outer periphery of the gas nozzle joint (3) is provided with a second annular groove (34); The front end of the front end cover (5) is clamped in the second annular groove (34).

7. The PFA pipe seamless welding support device according to claim 2, characterized in that: The rear end (12) of the airbag (1) is covered with a rear end cover (6) on its outer periphery; The axial tensioning assembly (2) comprises a tensioning member (21) and a fixing column (23) located at the rear end of the tensioning member (21); One end of the fixing column (23) is fixedly connected to the tensioning member (21), and the other end is passed through the tail portion (12) of the airbag (1) and the exposed portion is fixedly connected to the rear end cover (6).

8. The PFA pipe seamless welding support device according to claim 7, characterized in that: The fixing column (23) is threadably matched with the rear end cover (6).

9. The PFA pipe seamless welding support device according to claim 7, characterized in that: The portion of the fixing column (23) located inside the tail portion (12) of the airbag (1) is provided with an expanded diameter portion (231).

10. The PFA pipe seamless welding support device according to claim 2, characterized in that: A plurality of reinforcing ribs (131) are arranged inside the working portion (13).

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