Expansion joint

Abstract

The utility model provides an expansion joint, which belongs to the field of pipeline connection and comprises two expansion joint flanges which are symmetrically arranged, and an expansion joint annular groove is arranged on the outer side of any expansion joint flange. The corrugated pipe is arranged between the two expansion joint flanges and provided with a corrugated pipe body and two corrugated pipe bending parts, and the two corrugated pipe bending parts are arranged on the two sides of the corrugated pipe body and matched with the expansion joint annular grooves; the first flow guide pipe is arranged in the corrugated pipe and comprises a first flow guide pipe body and a first annular connecting part which are integrally formed, and the first annular connecting part is arranged on one side of any corrugated pipe bending part and matched with the annular groove of the expansion joint. The first annular connecting part is attached to the bent part of the corrugated pipe to be welded and fixed, fixed installation of the expansion joint flange, the corrugated pipe and the first flow guide pipe is completed, the welding failure caused by grain boundary corrosion and a stepped passage formed by the annular groove of the expansion joint are avoided, the air tightness of the expansion joint is improved, and the problem of air leakage of the connecting end face of the expansion joint is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of pipeline connection, in particular to an expansion joint. Background Art

[0002] In the design of diesel engines, the engine exhaust pipe needs to be connected to an expansion joint, which is a flexible structure, thereby compensating for additional stress caused by temperature difference and mechanical vibration. In order to achieve the connection between the exhaust pipe and the expansion joint, in the prior art, the ends of the exhaust pipe and the expansion joint are both provided with connecting flanges, the two connecting flanges are close to each other, and the two connecting flanges are connected as a whole by a clamp, and the two connecting flanges are sealed by a sealing gasket sandwiched between them.

[0003] Prior art patent No. 202020453124.6 discloses an expansion joint, including: an inlet end flange, a bellows, a guide tube and an outlet end flange. The guide tube is located inside the bellows, the inner surface of the inlet end flange includes an inlet straight face section and an inlet conical face section, the inlet end of the bellows is fixedly attached to the inlet straight face section and the inlet conical face section by brazing, the inner surface of the outlet end flange includes an outlet straight face section and an outlet conical face section, and the outlet end of the bellows is fixedly attached to the outlet straight face section and the outlet conical face section by brazing. The inlet end of the guide tube is fixedly attached to the inlet straight face section by brazing, and the outlet end of the guide tube is a free end and the free end extends into the outlet end flange.

[0004] In the above technology, the inlet end of the bellows and the inlet end of the guide tube are fixed at the brazing position by brazing. The weld is directly eroded by the high-temperature and high-speed exhaust gas flow, which is prone to intergranular corrosion. Intergranular corrosion is one of the most dangerous forms of local corrosion of alloys. This corrosion first occurs on the grain boundary and then develops along the grain boundary to the depth. In addition, the exhaust expansion joint vibrates violently during use. As a result, the bellows may become desoldered or broken. Utility Model Content

[0005] In view of the above problems, the utility model provides an expansion joint.

[0006] An expansion joint comprises: two expansion joint flanges, which are symmetrically arranged and an expansion joint annular groove is provided on the outer side of any expansion joint flange; a bellows, which is arranged between the two expansion joint flanges and comprises a bellows main body and two bellows bending parts, which are integrally arranged on both sides of the bellows main body and matched with the expansion joint annular groove; a first flow guide pipe, which is arranged inside the bellows and comprises an integrally formed first flow guide pipe main body and a first annular connecting part, which is arranged on one side of any bellows bending part and matched with the expansion joint annular groove.

[0007] In a preferred embodiment, the expansion joint also includes: a second flow guide pipe, the second flow guide pipe is arranged inside the bellows, and includes an integrally formed second flow guide pipe body and a second annular connecting portion, the second flow guide pipe body is arranged on the inner side or the outer side of the first flow guide pipe body, and is slidably connected to the first flow guide pipe body, and the second annular connecting portion is arranged in an annular groove of the expansion joint away from the side of the first annular connecting portion, and is matched with the annular groove of the expansion joint.

[0008] In a preferred embodiment, the expansion joint further comprises: two connecting pipe flanges, which are symmetrically arranged on both sides of the two expansion joint flanges.

[0009] In a preferred embodiment, a connecting pipe annular groove is provided on a side of the connecting pipe flange close to the expansion joint flange, and the connecting pipe annular groove is matched and connected with the first annular connecting portion and the second annular connecting portion.

[0010] In a preferred embodiment, the expansion joint further comprises: a sealing gasket disposed between the connecting pipe flange and the expansion joint flange.

[0011] In a preferred embodiment, the first annular connecting portion and the second annular connecting portion are fixedly connected to the annular groove of the expansion joint by welding.

[0012] In a preferred embodiment, the bent portion of the bellows is fixedly connected to the annular groove of the expansion joint by welding.

[0013] The expansion joint of the present application arranges two bellows bending parts in the annular groove of the expansion joint respectively, and then welds them to fix them. Then, the first annular connecting part of the first guide pipe is attached to the bending part of the bellows and welded to fix them, thereby completing the fixed installation of the expansion joint flange, the bellows, and the first guide pipe, thereby avoiding the open welding failure of the welding structure caused by intergranular corrosion. The stepped passage formed by the annular groove of the expansion joint can improve the air tightness of the expansion joint and solve the problem of air leakage at the connection end of the expansion joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Other characteristics, features and advantages of the present invention will become clear by reading the following description of the exemplary embodiments with reference to the accompanying drawings. The accompanying drawings, which are incorporated into the specification and constitute a part of the specification, illustrate embodiments of the present invention and are used together with the description to explain the principles of the present invention. In these drawings, similar reference numerals are used to represent similar elements. The drawings described below are some embodiments of the present invention, not all embodiments. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 Structural diagram of the expansion joint of the utility model;

[0016] Figure 2 A cross-sectional view of the expansion joint of the utility model;

[0017] Figure 3 A cross-sectional view of an embodiment of an expansion joint of the utility model;

[0018] Figure 4 A magnified view of the position A of the expansion joint of the utility model;

[0019] Figure 5 A magnified view of the position of the expansion joint B of the utility model;

[0020] In the figure: 10, expansion joint flange; 11, expansion joint annular groove; 20, bellows; 21, bellows body; 22, bellows bending portion; 30, first flow guide pipe; 31, first flow guide pipe body; 32, first annular connecting portion; 40, second flow guide pipe; 41, second flow guide pipe body; 42, second annular connecting portion; 50, connecting pipe flange; 51, connecting pipe annular groove; 52, sealing gasket. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the embodiment of the utility model clearer, the technical scheme in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model. It should be noted that the embodiments in this application and the features in the embodiments can be combined with each other arbitrarily without conflict.

[0022] The expansion joint is described in detail below in conjunction with the accompanying drawings and embodiments. Example

[0023] An expansion joint comprises: two expansion joint flanges 10, the two expansion joint flanges 10 are symmetrically arranged, and an expansion joint annular groove 11 is opened on the outside of any expansion joint flange 10; a bellows 20, arranged between the two expansion joint flanges 10, having a bellows body 21 and two bellows bending parts 22, the two bellows bending parts 22 are integrally arranged on both sides of the bellows body 21, and are matched with the expansion joint annular groove 11; a first guide pipe 30, arranged inside the bellows 20, comprising an integrally formed first guide pipe body 31 and a first annular connecting part 32, the first annular connecting part 32 is arranged on one side of any bellows bending part 22, and is matched with the expansion joint annular groove 11.

[0024] The first annular connecting portion 32 is fixedly connected to the annular groove 11 of the expansion joint.

[0025] The bellows bending portion 22 is fixedly connected to the expansion joint annular groove 11 by welding.

[0026] During installation, the two bellows bending portions 22 are respectively arranged in the annular groove 11 of the expansion joint, and then they are welded and fixed. Then the first annular connecting portion 32 of the first guide tube 30 is attached to a bellows bending portion 22 and welded and fixed, thereby completing the fixed installation of the expansion joint flange 10, the bellows 20, and the first guide tube 30, thereby avoiding the open welding failure of the welding structure caused by intergranular corrosion. The stepped passage formed by the annular groove 11 of the expansion joint can improve the air tightness of the expansion joint and solve the problem of air leakage at the connection end of the expansion joint.

[0027] The expansion joint further comprises: two connecting pipe flanges 50, which are symmetrically arranged on both sides of the two expansion joint flanges 10. The connecting pipe flanges 50 are arranged to facilitate connection with the exhaust pipe.

[0028] in, Example

[0029] Embodiment 2 is an improvement on Embodiment 1, and the improvement specifically includes that the expansion joint also includes: a second flow guide pipe 40, which is arranged inside the bellows 20, and includes an integrally formed second flow guide pipe body 41 and a second annular connecting portion 42, the second flow guide pipe body 41 is arranged on the inner side or the outer side of the first flow guide pipe body 31, and is slidingly connected to the first flow guide pipe body 31, and the second annular connecting portion 42 is arranged in the expansion joint annular groove 11 on the side away from the first annular connecting portion 32, and is matched with the expansion joint annular groove 11.

[0030] The second annular connecting portion 42 is fixedly connected to the annular groove 11 of the expansion joint by welding.

[0031] During installation, a first guide tube 30 and a second guide tube 40 are provided inside the bellows 20 for sliding connection, so as to avoid the high-temperature exhaust gas from contacting the bellows 20 as much as possible and reduce the intergranular corrosion of the bellows welding part caused by the exhaust gas.

[0032] The annular structures of the first annular connecting portion 32 and the second annular connecting portion 42 are rectangular annular structures, which can be easily matched and connected with the annular groove 11 of the expansion joint. Example

[0033] Embodiment 3 is an improvement on Embodiment 1, and the improvement specifically includes that the expansion joint further includes: two connecting pipe flanges 50, which are symmetrically arranged on both sides of the two expansion joint flanges 10. A connecting pipe annular groove 51 is provided on the side of the connecting pipe flange 50 close to the expansion joint flange 10, and the connecting pipe annular groove 51 is matched and connected with the first annular connecting portion 32 and the second annular connecting portion 42.

[0034] Among them, by setting the connecting pipe flange 50, it is convenient to connect with the exhaust pipe; and by setting the connecting pipe annular groove 51, the first annular connecting part 32 and the second annular connecting part 42 are set on one side of the connecting pipe annular groove 51, which can facilitate the installation and fixing of the connecting pipe flange 50, and finally the connecting pipe flange 50 is fixedly connected to the expansion joint flange 10 by bolts and nuts.

[0035] The expansion joint further comprises a sealing gasket 52, which is arranged between the connecting pipe flange 50 and the expansion joint flange 10. By arranging the sealing gasket 52, the sealing performance between the connecting pipe flange 50 and the expansion joint flange 10 is improved, and air leakage between the connecting pipe flange 50 and the expansion joint flange 10 is avoided.

[0036] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that an article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such article or device. In the absence of further restrictions, the elements defined by the sentence "includes..." do not exclude the existence of other identical elements in the article or device including the elements.

[0037] The above embodiments are only used to illustrate the technical solution of the utility model but not to limit it. The utility model is described in detail with reference to the preferred embodiments. It should be understood by those skilled in the art that the technical solution of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the utility model, and all should be included in the scope of the claims of the utility model.

Claims

1. An expansion joint, characterized in that: include: Two expansion joint flanges (10), the two expansion joint flanges (10) are symmetrically arranged, and an expansion joint annular groove (11) is provided on the outer side of any one of the expansion joint flanges (10); A bellows (20) is arranged between the two expansion joint flanges (10), comprising a bellows body (21) and two bellows bent portions (22); the two bellows bent portions (22) are integrally arranged on both sides of the bellows body (21) and are matched with the expansion joint annular groove (11); The first flow guide pipe (30) is arranged inside the bellows (20), and comprises an integrally formed first flow guide pipe body (31) and a first annular connecting portion (32); the first annular connecting portion (32) is arranged on one side of any bellows bending portion (22) and matches the expansion joint annular groove (11).

2. The expansion joint according to claim 1, characterized in that: The expansion joint also includes: A second flow guide pipe (40), the second flow guide pipe (40) is arranged inside the bellows (20), and comprises an integrally formed second flow guide pipe body (41) and a second annular connecting portion (42), the second flow guide pipe body (41) being arranged on the inside or outside of the first flow guide pipe body (31) and being slidably connected to the first flow guide pipe body (31), and the second annular connecting portion (42) being arranged in the expansion joint annular groove (11) on a side away from the first annular connecting portion (32) and being arranged to match the expansion joint annular groove (11).

3. The expansion joint according to claim 2, characterized in that The expansion joint also includes: The two connecting pipe flanges (50) are symmetrically arranged on both sides of the two expansion joint flanges (10).

4. The expansion joint according to claim 3, characterized in that A connecting pipe annular groove (51) is provided on a side of the connecting pipe flange (50) close to the expansion joint flange (10), and the connecting pipe annular groove (51) is matched and connected with the first annular connecting portion (32) and the second annular connecting portion (42).

5. The expansion joint according to claim 4, characterized in that The expansion joint also includes: A sealing gasket (52) is arranged between the connecting pipe flange (50) and the expansion joint flange (10).

6. The expansion joint of claim 4, characterized in that The first annular connecting portion (32) and the second annular connecting portion (42) are fixedly connected to the expansion joint annular groove (11) by welding.

7. The expansion joint of claim 1, characterized in that The bellows bending portion (22) is fixedly connected to the expansion joint annular groove (11) by welding.

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