Expansion joint, engine exhaust system and engine

Abstract

The utility model relates to an expansion joint, engine exhaust system and engine, the expansion joint includes corrugated pipe, corrugated pipe includes a plurality of first wave crest structure and a plurality of second wave crest structure, all first wave crest structure are arranged along the axial direction of corrugated pipe at interval, a second wave crest structure is arranged between every two adjacent first wave crest structure, the size of the first wave crest structures in the radial direction of the corrugated pipe is larger than that of the second wave crest structures in the radial direction of the corrugated pipe. According to the expansion joint, the two adjacent higher first wave crest structures are separated through the lower second wave crest structures, under the action of the same extrusion force of an existing structure, it can be guaranteed that the two adjacent first wave crest structures cannot extrude each other, the capacity of the expansion joint for bearing inclined deformation of the two adjacent first wave crest structures is effectively improved, and the service life of the expansion joint is prolonged. And two adjacent first wave crest structures are prevented from being extruded and broken, and the service life of the expansion joint is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of engines, in particular to an expansion joint, an engine exhaust system and an engine. Background Art

[0002] When the engine is undergoing endurance testing, the exhaust temperature of the exhaust pipe may be as high as 760°C. Under the action of high temperature, the exhaust pipe will undergo thermal deformation. Since the thermal deformation of the exhaust pipe is mainly along the axial direction, the expansion joint between the exhaust pipes will be squeezed, and the extrusion force of the exhaust pipe along the axial direction on the expansion joint is different in radial direction. Therefore, when the extrusion amount generated by the exhaust pipe is greater than the compensating compression amount of the expansion joint, the expansion joint will be squeezed. Due to the different extrusion forces in the radial direction, the adjacent corrugations will produce tilted deformation due to the extrusion force, such as Figure 1 As shown, the peak structures of the bellows of the existing expansion joint have the same size and are densely arranged. Therefore, when adjacent peak structures are tilted and deformed due to the extrusion force, the two adjacent peak structures will produce parallel wave extrusion, causing deformation or even rupture, which in turn leads to air leakage. Utility Model Content

[0003] The first purpose of the present invention is to provide an expansion joint to avoid the problem that the thermal deformation of the exhaust pipe is greater than the compensating compression of the expansion joint, which causes the corrugated structure of the expansion joint to tilt and cause extrusion and rupture, thereby causing air leakage.

[0004] A second object of the present invention is to provide an engine exhaust system and an engine including the above-mentioned expansion joint.

[0005] To achieve the above objectives, the present invention provides the following technical solutions:

[0006] An expansion joint includes a bellows, the bellows including a plurality of first wave peak structures and a plurality of second wave peak structures, the first wave peak structures and the second wave peak structures both protrude in the radial direction of the bellows away from the internal space of the bellows, the first wave peak structures are arranged at intervals along the axial direction of the bellows, the second wave peak structure is arranged between two adjacent first wave peak structures, and the size of the first wave peak structure along the radial direction of the bellows is greater than the size of the second wave peak structure along the radial direction of the bellows.

[0007] In one embodiment of the present application, the size of the first wave peak structure along the radial direction of the corrugated tube is at least twice the size of the second wave peak structure along the radial direction of the corrugated tube.

[0008] In one embodiment of the present application, at least two second wave peak structures are arranged between two adjacent first wave peak structures.

[0009] In one embodiment of the present application, the expansion joint further includes a first end pipe and a second end pipe, the first end pipe and the second end pipe are respectively arranged at both ends of the corrugated pipe, and the first end pipe and the second end pipe are respectively used to connect to the exhaust pipes at both ends of the expansion joint.

[0010] In one embodiment of the present application, the first end tube is provided with a flow guide tube, which extends from the inner space of the corrugated tube toward the second end tube, and a gap is provided between the flow guide tube and the corrugated tube.

[0011] In one embodiment of the present application, a flange structure for connecting to the exhaust pipe is provided at one end of the first end pipe and the second end pipe away from the bellows.

[0012] In one embodiment of the present application, the expansion joint further includes a tie structure, the two ends of which are respectively connected to the first end tube and the second end tube, and the tie structure is used to make the relative rotation angle of the first end tube and the second end tube within a preset range.

[0013] In one embodiment of the present application, the pulling structure includes a first pull rod and a second pull rod, the first pull rod is rotatably connected to the first end tube, the second pull rod is rotatably connected to the second end tube, the first pull rod and the second pull rod are rotatably connected, and at least one of the three places between the first pull rod and the first end tube, between the second pull rod and the second end tube, and between the first pull rod and the second pull rod is a sliding connection that can move back and forth along the axial direction of the corrugated tube, and a stop limit structure is provided between the first pull rod and the second pull rod, and the stop limit mechanism is used to prevent the relative rotation angle of the first pull rod and the second pull rod from exceeding a preset range.

[0014] An engine exhaust system comprises an exhaust pipe, wherein the exhaust pipe is provided with an expansion joint as described in any one of the above items.

[0015] An engine comprises the engine exhaust system as described above.

[0016] It can be seen from the above technical solution that the utility model discloses an expansion joint, which includes a bellows, and the bellows includes a plurality of first wave peak structures and a plurality of second wave peak structures. The first wave peak structure and the second wave peak structure both protrude in the radial direction of the bellows away from the internal space of the bellows, and the first wave peak structures are arranged at intervals along the axial direction of the bellows. A second wave peak structure is arranged between two adjacent first wave peak structures, and the size of the first wave peak structure along the radial direction of the bellows is larger than the size of the second wave peak structure along the radial direction of the bellows.

[0017] It can be seen that the above-mentioned expansion joint is separated by a lower second wave peak structure between two adjacent higher first wave peak structures, thereby increasing the axial distance between the two adjacent first wave peak structures. When the exhaust pipe is deformed by heat, the first wave peak structure with a larger radial dimension is obviously more prone to tilt deformation than the second wave peak structure. The deformation will preferentially occur at the first wave peak structure. However, since the two adjacent first wave peak structures are far apart, under the action of the same extrusion force of the existing structure, it can be ensured that the two adjacent first peak structures will not squeeze each other, which can effectively improve the ability of the expansion joint to withstand the tilt deformation of the two adjacent first peak structures, reduce the probability of the two adjacent first peak structures merging, thereby avoiding the mutual squeezing and rupture of the two adjacent first peak structures, and further improve the service life of the expansion joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 It is a structural diagram of an expansion joint in the prior art;

[0020] Figure 2 A partial cross-sectional view of an expansion joint provided in an embodiment of the present utility model;

[0021] Figure 3 This is a schematic structural diagram of an expansion joint provided in an embodiment of the present utility model.

[0022] In the picture:

[0023] 1 is an exhaust pipe; 2 is an expansion joint; 210 is a bellows; 211 is a first wave crest structure; 212 is a second wave crest structure; 220 is a first end pipe; 230 is a second end pipe; 240 is a guide pipe; 250 is an annular boss; 260 is an annular groove; 270 is a tie structure; 271 is a first tie rod; 272 is a second tie rod. DETAILED DESCRIPTION

[0024] One of the cores of the present invention is to provide an expansion joint, the structural design of which can prevent the thermal deformation of the exhaust pipe from being greater than the compensating compression of the expansion joint, causing the corrugated structure of the expansion joint to tilt and produce extrusion rupture, thereby causing air leakage.

[0025] Another core of the present invention is to provide an engine exhaust system and an engine including the above-mentioned expansion joint.

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] See also Figure 2 , Figure 2 A partial cross-sectional view of an expansion joint provided in an embodiment of the present utility model.

[0028] An embodiment of the present invention discloses an expansion joint 2, which includes a bellows 210. The bellows 210 includes a plurality of first wave peak structures 211 and a plurality of second wave peak structures 212. The first wave peak structures 211 and the second wave peak structures 212 both protrude in the radial direction of the bellows 210 in a direction away from the internal space of the bellows 210. The first wave peak structures 211 are arranged at intervals along the axial direction of the bellows 210. A second wave peak structure 212 is provided between two adjacent first wave peak structures 211, that is, at least one second wave peak structure 212 is provided between two adjacent first wave peak structures 211. The size of the first wave peak structure 211 along the radial direction of the bellows 210 is greater than the size of the second wave peak structure 212 along the radial direction of the bellows 210.

[0029] It should be noted that the above-mentioned first wave peak structure 211 and second wave peak structure 212 refer to structures protruding radially outward from the bellows 210 when observed from the external space of the bellows 210 of the expansion joint 2. Correspondingly, if observed from the internal space of the bellows 210, what protrudes radially is the trough structure between the first wave peak structure 211 and the second wave peak structure 212 or between two adjacent second wave peak structures 212. In the embodiment of the present utility model, the radial dimensions of each trough structure are consistent.

[0030] Compared with the prior art, the expansion joint 2 provided in the embodiment of the present invention is separated by a lower second wave peak structure 212 between two adjacent higher first wave peak structures 211, thereby increasing the axial distance between the two adjacent first wave peak structures 211. When the exhaust pipe 1 is deformed by heat, the first wave peak structure 211 with a larger radial dimension is obviously more prone to tilt deformation than the second wave peak structure 212, and the deformation will preferentially occur at the first wave peak structure 211. However, since the two adjacent first wave peak structures 211 are far apart, under the action of the same extrusion force of the existing structure, it can be ensured that the two adjacent first wave peak structures 211 will not be squeezed against each other, which can effectively improve the ability of the expansion joint 2 to withstand the tilt deformation of the two adjacent first wave peak structures 211, reduce the probability of the two adjacent first wave peak structures 211 merging, thereby avoiding the mutual squeezing and rupture of the two adjacent first wave peak structures 211, and further improve the service life of the expansion joint 2.

[0031] In order to make the expansion joint 2 deform mainly at the first wave crest structure 211 and reduce the deformation at the second wave crest structure 212 when the force generated by the axial deformation of the exhaust pipe 1 is applied, in the embodiment of the present utility model, Figure 2 As shown, the size of the first wave peak structure 211 along the radial direction of the bellows 210 is at least twice the size of the second wave peak structure 212 along the radial direction of the bellows 210 .

[0032] To further optimize the above technical solution, in order to further increase the axial distance between two adjacent first wave peak structures 211, in the embodiment of the present utility model, as shown in FIG. Figure 2 As shown, at least two second wave peak structures 212 are arranged between two adjacent first wave peak structures 211 .

[0033] like Figure 3 As shown, in an embodiment of the present invention, the expansion joint 2 further includes a first end pipe 220 and a second end pipe 230, which are respectively arranged at both ends of the bellows 210, and the first end pipe 220 and the second end pipe 230 are respectively used to seal and connect with the exhaust pipe 1 at both ends of the expansion joint 2, and the first end pipe 220 and the second end pipe 230 are connected through the bellows 210, so that the first end pipe 220 and the second end pipe 230 can move relative to each other in the axial direction and can rotate relative to each other.

[0034] Further optimize the above technical solutions, such as Figure 3 As shown, the first end tube 220 is provided with a guide tube 240, which extends from the internal space of the bellows 210 toward the second end tube 230. A gap is provided between the guide tube 240 and the bellows 210. When the bellows 210 undergoes axial deformation, the gap between the bellows 210 and the guide tube 240 can prevent the bellows 210 from being damaged due to friction between the guide tube 240.

[0035] In order to facilitate the connection of the first end pipe 220 and the second end pipe 230 with the exhaust pipe 1, in the embodiment of the present utility model, the ends of the first end pipe 220 and the second end pipe 230 away from the bellows 210 are provided with flange structures for connecting with the exhaust pipe 1, such as Figure 3 As shown, an annular boss 250 is provided on the end face of the flange structure of the first end pipe 220 and the second end pipe 230 located downstream along the exhaust direction, and an annular groove 260 is provided on the end face of the flange structure of the upstream end pipe. The annular boss 250 is used to be inserted into the downstream exhaust pipe 1, and the annular groove 260 is used for the upstream exhaust pipe 1 to be inserted, so as to reduce the risk of air leakage at the connection between the expansion joint 2 and the exhaust pipe 1.

[0036] like Figure 3 As shown, in an embodiment of the present invention, the expansion joint 2 further includes a tie structure 270, the two ends of which are respectively connected to the first end tube 220 and the second end tube 230, and the tie structure 270 is used to make the relative rotation angle of the first end tube 220 and the second end tube 230 within a preset range.

[0037] Specifically, in the embodiment of the present utility model, the above-mentioned tie structure 270 includes a first tie rod 271 and a second tie rod 272, the first tie rod 271 is rotatably connected to the first end tube 220, the second tie rod 272 is rotatably connected to the second end tube 230, the first tie rod 271 and the second tie rod 272 are rotatably connected, and at least one of the three places between the first tie rod 271 and the first end tube 220, between the second tie rod 272 and the second end tube 230, and between the first tie rod 271 and the second tie rod 272 is rotatably connected to the bellows 210. A sliding connection for axial reciprocating movement, a stop limit structure is provided between the first pull rod 271 and the second pull rod 272, and the stop limit mechanism is used to ensure that the relative rotation angle between the first pull rod 271 and the second pull rod 272 does not exceed a preset range. Through the above structural design, the tie structure 270 will not affect the expansion and contraction of the expansion joint 2, and the first end tube 220 and the second end tube 230 can rotate relative to each other within a preset range, further reducing the problem of parallel wave extrusion between the two adjacent first wave peak structures 211, and improving the reliability and durability of the expansion joint 2.

[0038] An embodiment of the present invention also provides an engine exhaust system, which includes an exhaust pipe 1, on which is arranged an expansion joint 2 as described in the above embodiment. Since the engine exhaust system adopts the expansion joint 2 in the above embodiment, the technical effects of the engine exhaust system please refer to the above embodiment.

[0039] Furthermore, an embodiment of the present invention also provides an engine that adopts the above-mentioned engine exhaust system, and the engine includes the engine exhaust system as described in the above-mentioned embodiment. The engine includes but is not limited to a gasoline engine, a diesel engine, and a natural gas engine.

[0040] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referenced to each other.

[0041] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help you understand the core concept of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. An expansion joint, characterized in that: It includes a bellows, which includes multiple first wave peak structures and multiple second wave peak structures. The first wave peak structures and the second wave peak structures both protrude in the radial direction of the bellows away from the internal space of the bellows. The first wave peak structures are arranged at intervals along the axial direction of the bellows, and the second wave peak structure is arranged between two adjacent first wave peak structures. The size of the first wave peak structure along the radial direction of the bellows is larger than the size of the second wave peak structure along the radial direction of the bellows.

2. The expansion joint according to claim 1, characterized in that A dimension of the first wave peak structure along the radial direction of the corrugated tube is at least twice a dimension of the second wave peak structure along the radial direction of the corrugated tube.

3. The expansion joint according to claim 1, characterized in that At least two second wave peak structures are arranged between two adjacent first wave peak structures.

4. The expansion joint according to any one of claims 1 to 3, characterized in that: The expansion joint further includes a first end pipe and a second end pipe, the first end pipe and the second end pipe are respectively arranged at both ends of the bellows, and the first end pipe and the second end pipe are respectively used to connect with the exhaust pipes at both ends of the expansion joint.

5. The expansion joint according to claim 4, characterized in that The first end tube is provided with a flow guide tube, and the flow guide tube extends from the inner space of the corrugated tube toward the second end tube, and a gap is provided between the flow guide tube and the corrugated tube.

6. The expansion joint according to claim 4, characterized in that The first end pipe and the second end pipe are provided with flange structures for connecting to the exhaust pipe at one end away from the corrugated pipe.

7. The expansion joint according to claim 4, characterized in that The expansion joint further includes a tie structure, both ends of which are connected to the first end tube and the second end tube respectively, and the tie structure is used to ensure that the relative rotation angle between the first end tube and the second end tube is within a preset range.

8. The expansion joint according to claim 7, characterized in that The pulling structure includes a first pull rod and a second pull rod, the first pull rod is rotatably connected to the first end tube, the second pull rod is rotatably connected to the second end tube, the first pull rod and the second pull rod are rotatably connected, at least one of the three places between the first pull rod and the first end tube, between the second pull rod and the second end tube, and between the first pull rod and the second pull rod is a sliding connection that can move back and forth along the axial direction of the corrugated tube, and a stop limit structure is provided between the first pull rod and the second pull rod, and the stop limit mechanism is used to prevent the relative rotation angle of the first pull rod and the second pull rod from exceeding a preset range.

9. An engine exhaust system, characterized in that: The engine exhaust system includes an exhaust pipe, and the exhaust pipe is provided with an expansion joint according to any one of claims 1 to 8.

10. An engine, characterized in that: The engine includes the engine exhaust system of claim 9 .

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