CN114962823A

CN114962823A - Clamp and pipeline structure with same for internal combustion engine

Info

Publication number: CN114962823A
Application number: CN202111543871.4A
Authority: CN
Inventors: 黄立; 李丽婷; 王春辉; 张国勇; 王彪; 张茂胜
Original assignee: Shanghai Marine Diesel Engine Research Institute
Current assignee: Shanghai Marine Diesel Engine Research Institute
Priority date: 2021-12-16
Filing date: 2021-12-16
Publication date: 2022-08-30
Also published as: CN118208605A

Abstract

The invention discloses a clamp and a pipeline structure for an internal combustion engine with the same. The clamp includes two pipe hoops and bolt assembly, the pipe hoop includes pipe hoop portion and shoulder, pipe hoop portion is the arc structure, the both ends of the first radial direction of pipe hoop portion of edge of pipe hoop portion all are provided with the shoulder, the shoulder has the installation through-hole that the axis extends along the second radial direction of pipe hoop portion, the first radial direction of second radial direction perpendicular to, the size of the second radial direction of pipe hoop portion of edge of shoulder is H, the radius size of pipe hoop portion is R, the scope of H is 0.5R and is less than or equal to H and is less than or equal to R, bolt assembly includes bolt and nut, the bolt is used for wearing to locate behind the installation through-hole and nut is connected, in order to connect two pipe hoops. Therefore, the range of H is more than or equal to 0.5R and less than or equal to H, the rigidity and the strength of the pipe hoop can be increased, the possibility of local arching caused by bending deformation of the pipe hoop part is reduced, and the possibility of leakage caused by untight sealing of the pipeline at the joint can be further reduced.

Description

Clamp and have its pipeline structure for internal-combustion engine

Technical Field

The invention relates to the field of pipeline connection, in particular to a clamp and a pipeline structure with the clamp for an internal combustion engine.

Background

With the development of internal combustion engines toward high power density and high reliability. The compact design of internal combustion engines is of increasing interest. The requirement for compactness of the exhaust pipe of the internal combustion engine is not only related to the reliability of exhaust sealing, but also related to the safety of the whole engine. The clamp is used for connecting the structure of the exhaust pipe, and the reasonability of the structure of the clamp directly influences the sealing performance of the exhaust pipe and the connection strength of the exhaust pipe.

The existing wafer clamp comprises a first clamp and a second clamp. The first clamp and the second clamp are used for clamping the exhaust pipe. The clamp has a shoulder. The shoulder is provided with a mounting hole to provide a bolt and a nut so as to connect the first clamp and the second clamp through the bolt and the nut, thereby enabling the first clamp and the second clamp to clamp the exhaust pipe.

However, the shoulder height of the prior wafer-clip type clamp is small. When the first clamp and the second clamp the pipeline, and when the internal combustion engine works, the shaft shoulder is easy to deform, and the pipeline is easy to leak.

To this end, the present invention provides a clamp and a pipe structure for an internal combustion engine having the same to at least partially solve the above problems.

Disclosure of Invention

In this summary, concepts in a simplified form are introduced that are further described in the detailed description section. This summary of the invention is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

To at least partially solve the above technical problem, the present invention provides a clamp band, including:

the pipe hoop part is of an arc structure, the two ends of the pipe hoop part along the first radial direction of the pipe hoop part are provided with the convex shoulders, each convex shoulder is provided with an installation through hole of which the axis extends along the second radial direction of the pipe hoop part, the second radial direction is perpendicular to the first radial direction, the dimension of the convex shoulders along the second radial direction of the pipe hoop part is H, the radius dimension of the pipe hoop part is R, the range of H is more than or equal to 0.5R and less than or equal to H and less than or equal to R,

bolt assembly, bolt assembly include bolt and nut, and the bolt is used for wearing to locate behind the installation through-hole and is connected with the nut to connect two pipe hoops.

According to the clamp, the range of H is more than or equal to H and less than or equal to R and is 0.5R, so that the rigidity and the strength of the pipe clamp can be increased, the possibility of local arching caused by bending deformation of the pipe clamp part is reduced, and the possibility of leakage caused by untight sealing of a pipeline at a joint can be further reduced.

Optionally, the shoulder mounting surface of the shoulder portion, which is close to the head portion of the bolt assembly, is an inclined surface, the inclined surface having an inclined outer end and an inclined inner end, along a first radial direction of the collar portion, the inclined outer end is located on one side of the inclined outer end, which is far away from the center of the arc structure, and along a second radial direction of the collar portion, the inclined inner end is located on one side of the inclined outer end, which is close to the center of the arc structure.

Optionally, the shoulder portion of the shoulder portion is close to the second radial direction of the collar portion of the head of the bolt assembly, the clamp includes a wedge-shaped gasket, under the condition that the bolt assembly connects two collars, the screw rod of the bolt is located to the wedge-shaped gasket cover, the wedge-shaped gasket overlap joint to the shoulder portion of the bolt to make the surface of the head of the bolt assembly close to and adjacent to the wedge-shaped gasket be the inclined plane, along the first radial direction of the collar portion, the great one end of the thickness of the wedge-shaped gasket is used for setting up in the one side of the body of rod of the bolt that is far away from the centre of a circle of the arc structure.

Optionally, the angle α between the inclined surface and the first radial direction of the collar portion is in the range 0 ° < α ≦ 20 °.

Optionally, the coefficient of linear expansion of the material of the bolt is less than or equal to the coefficient of linear expansion of the material of the pipe clamp.

Alternatively,

the coefficient of linear expansion of the material of the bolt is less than or equal to 14, and/or

The material of the clamp has a linear expansion coefficient less than or equal to 17.

Optionally, the cross-sectional shape of the collar portion has a V-shaped groove.

The present invention also provides a pipe structure for an internal combustion engine, including: at least two pipes, and a clamp as described above for connecting adjacent pipes.

According to the pipeline structure for the internal combustion engine, the pipeline structure for the internal combustion engine comprises the clamp, H is within the range of 0.5R to H, wherein H is not less than H and not more than R, the rigidity and the strength of the pipe clamp can be increased, the possibility that the pipe clamp part is bent and deformed to be locally arched is reduced, and the possibility that the pipeline leaks due to untight sealing at the joint can be further reduced.

Optionally, the end of the pipeline is provided with a connecting flange, the clamp is used for connecting the connecting flanges of adjacent pipelines to connect the adjacent pipelines, the pipeline structure further comprises a sealing gasket, the sealing gasket is used for being arranged between the connecting flanges of the adjacent pipelines to seal a gap between the connecting flanges of the adjacent pipelines, and the coefficient of linear expansion of the material of the pipe clamp is smaller than or equal to that of the material of the connecting flanges.

Drawings

In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings.

FIG. 1 is a front view of a clamp band according to a first preferred embodiment of the present invention, with portions broken away;

FIG. 2 is an enlarged partial view of the clamp of FIG. 1 at A, with the bolts not shown;

FIG. 3 is a schematic cross-sectional view at B-B of the clamp of FIG. 1;

FIG. 4 is a schematic cross-sectional view of a connecting flange and a sealing gasket of the clamp connection conduit of FIG. 1;

FIG. 5 is a front view of a clamp band according to a second preferred embodiment of the present invention, with portions broken away;

FIG. 6 is an enlarged partial view of the clamp of FIG. 5 at C;

FIG. 7 is a graph of contact pressure distribution of the surface of an experimental gasket seal; and

fig. 8 is a graph of the stresses on the inside and outside of the shank of another experimental bolt.

Description of the reference numerals

110. Pipe clamp 111, pipe clamp portion

112. Shoulder 113, mounting through hole

114. First pipe clamp 115 and second pipe clamp

116. V-shaped groove 121 and bolt

122. Nut 131, inclined surface

132. Beveled outer end 133, beveled inner end

140. Sealing gasket 150 and connecting flange

211. Pipe hoop part 212, shoulder part

221. Bolt 222 and nut

231. Inclined surface 227, shoulder mounting surface

240. Wedge-shaped gasket

Detailed Description

In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that embodiments of the invention may be practiced without one or more of these specific details. In other instances, well-known features have not been described in detail so as not to obscure the embodiments of the invention.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It is to be understood that the terms "upper", "lower", and the like are used herein for purposes of illustration only and are not to be construed as limiting.

Ordinal words such as "first" and "second" are referred to herein merely as labels, and do not have any other meaning, e.g., a particular order, etc. Also, for example, the term "first spatial member" does not itself imply the presence of "second spatial member", and the term "second spatial member" does not itself imply the presence of "first spatial member".

In the following description, a detailed structure will be presented for a thorough understanding of embodiments of the invention. It is apparent that the implementation of the embodiments of the present invention is not limited to the specific details familiar to those skilled in the art. The following detailed description of preferred embodiments of the invention, however, the invention is capable of other embodiments in addition to those detailed.

First embodiment

The invention provides a clamp. Referring to fig. 1-4, the clamp is used to connect two pipes. As shown in fig. 4, the end of the pipe has a connection flange 150. The connection flange 150 extends radially outwardly of the pipe. The attachment flange 150 is configured as a circumferentially continuous structure about the axis of the pipe. The connection flanges 150 of the two pipes are connected to communicate the two pipes. The clamp embraces the joined-together flanges 150 of the two pipes to join the two pipes. A sealing gasket 140 is provided between the coupling flanges 150 to seal a gap between the two coupling flanges 150. The sealing gasket 140 may be a rubber sealing gasket.

As shown in fig. 1, the clamp includes two pipe clamps 110. The pipe clamp 110 includes a pipe clamp portion 111 and a shoulder portion 112. The collar portion 111 has an arc-shaped structure. The band embraces the pipe's attachment flange 150 through the band portion 111 to attach the pipe.

Referring to fig. 1 and 2, shoulder 112 includes a first shoulder and a second shoulder. The first shoulder portion is located at one end of the pipe clamp portion 111 in the first radial direction D1 (left-right direction in fig. 1) of the pipe clamp portion 111. The second shoulder is located at the other end of the pipe clamp portion 111 in the first radial direction D1 of the pipe clamp portion 111. The shoulder portion 112 has a mounting through hole 113. The axis of the mounting through hole 113 extends in the second radial direction D2 (the up-down direction in fig. 1) of the pipe clamp portion 111. The first radial direction D1 of the band portion 111 is perpendicular to the second radial direction D2 of the band portion 111. The position of the first shoulder and the position of the second shoulder are symmetrical with respect to the second radial direction D2 of the pipe clamp portion 111 along the first radial direction D1 of the pipe clamp portion 111.

The two pipe clamps 110 include a first pipe clamp 114 and a second pipe clamp 115. The clamp also includes a bolt assembly. The bolt assembly includes a bolt 121 and a nut 122. The bolt 121 is inserted into the mounting through hole 113. The openings of the first pipe clamp 114 and the second pipe clamp 115 are opposite. The first shoulder of the first pipe clamp 114 is opposite the first shoulder of the second pipe clamp 115. The second shoulder of the first pipe clamp 114 is opposite the second shoulder of the second pipe clamp 115.

The bolt 121 passes through the shoulder 112 of the first pipe clamp 114 and the shoulder 112 of the second pipe clamp 115 in sequence, and then is coupled with the nut 122. Specifically, a bolt 121 is inserted through the first shoulder portion of the first pipe clamp 114 and the first shoulder portion of the second pipe clamp 115, and then coupled to a nut 122. The other bolt 121 passes through the second shoulder portion of the first pipe clamp 114 and the second shoulder portion of the second pipe clamp 115 in sequence, and then is coupled with the other nut 122. Thus, tightening the bolts 121 of the pipe clamp 110 causes the first pipe clamp 114 and the second pipe clamp 115 to clamp the pipe connection flange 150 therein.

The dimension of the shoulder portion 112 in the second radial direction D2 of the collar portion 111 is H. The pipe clamp portion 111 has a radius dimension R. H is within the range of 0.5R-H. This can increase the rigidity and strength of the pipe clamp 110, and reduce the possibility that the pipe clamp portion 111 is bent and deformed to be locally arched. Further preferably, H ═ 0.6R.

In the present embodiment, H is in the range of 0.5R ≦ H ≦ R, which can increase the rigidity and strength of the pipe clamp 110, reduce the possibility of local arching due to bending deformation of the pipe clamp portion 111, and further reduce the possibility of leakage due to untight sealing of the pipe at the joint.

With continuing reference to fig. 1 and 2, in particular, with reference to fig. 1 and 2, along the second radial direction D2 of the pipe hoop portion 111, a side surface of the shoulder portion 112 away from the center of the arc-shaped structure is a shoulder mounting surface. The shoulder mounting surface is configured as an inclined surface 131. The inclined surface 131 is inclined to the first radial direction D1 of the pipe clamp portion 111. Specifically, the ramped surface 131 has a ramped outer end 132 and a ramped inner end 133. In the first radial direction D1 of the pipe clamp portion 111, the outer ramp end 132 is located on a side of the inner ramp end 133 away from the center of the arc-shaped structure. In the second radial direction D2 of the pipe clamp portion 111, the inner beveled end 133 is closer to the center of the arc structure than the outer beveled end 132.

With the bolts 121 tightened, the mounting surfaces of the bolt assemblies are progressively closer to the shoulder portions 112. Thus, the mounting face of the bolt assembly first abuts the beveled outer end 132. As the bolt 121 continues to be tightened, the action of the mounting surface of the bolt assembly against the beveled outer end 132 gradually deforms the shoulder 112 such that the shoulder mounting surface is gradually perpendicular to the second radial direction D2 of the pipe clamp portion 111. When the bolts 121 are tightened to a predetermined preload force, the shoulder mounting surfaces are substantially perpendicular to the second radial direction D2 of the pipe clamp portion 111, and the mounting surfaces of the bolt assemblies are conformed to the shoulder mounting surfaces. At this time, the axis of the bolt 121 is substantially parallel to the second radial direction D2 of the pipe clamp portion 111. Thus, the stress on the rod of the bolt 121 is uniform, the stress on the inner side of the rod of the bolt 121 (the side end of the rod away from the outer end 132 of the inclined plane) can be reduced, and the possibility of breakage of the bolt 121 can be reduced.

In addition, the surface of the sealing gasket 140 between the coupling flanges 150 can be uniformly stressed, thereby improving the sealing performance.

The angle between the inclined surface 131 and the first radial direction D1 of the pipe clamp portion 111 ranges from 0 ° to 20 °. Therefore, the internal stress of the rod body of the bolt 121 can be further reduced, and the possibility of breakage of the bolt 121 can be further reduced.

It is further preferred that the angle between the inclined surface 131 and the first radial direction D1 of the pipe clamp portion 111 is 5 °.

Preferably, the coefficient of linear expansion of the material of the bolt 121 is less than or equal to the coefficient of linear expansion of the material of the pipe clamp 110. Accordingly, when the pipe clamp is operated in a high-temperature environment, the first pipe clamp 114 and the second pipe clamp 115 connected by the bolt 121 can be prevented from being loosened, and thus leakage can be prevented as much as possible.

Preferably, the coefficient of linear expansion X1 of the material of bolt 121 ranges from 0 < X1 ≦ 14. Thereby, the selection of the bolt 121 is facilitated.

Preferably, the linear expansion coefficient X2 of the material of the pipe clamp 110 is in the range of 0 < X2 ≦ 17. Thereby, the selection of the type of the pipe clamp 110 is facilitated.

Preferably, the material of the bolt 121 is 06Cr25Ni 20. Thereby, the selection of the bolt 121 is facilitated.

Preferably, the material of the pipe clamp 110 is 25Cr2 MoVA. Thereby, the selection of the type of the pipe clamp 110 is facilitated.

Preferably, the pipe clamp 110 may be of an integrally formed structure. For example, the pipe clamp 110 may be a casting. Thereby facilitating the processing of the pipe clamp 110. The first and second pipe clamps 114 and 115 may be identical in structure. Therefore, the replacement is convenient.

With the first pipe clamp 114 and the second pipe clamp 115 clasping the connection flange, a space exists between the first pipe clamp 114 and the second pipe clamp 115 along the first radial direction D1 of the pipe clamp portion 111.

The invention also provides a pipeline structure for the internal combustion engine. As shown in fig. 4, the pipe structure includes at least two pipes, the aforementioned clips, and the aforementioned sealing gaskets 140. The end of the pipe has the aforementioned attachment flange 150. At least two pipes are connected in sequence so as to communicate. The conduit is for connection to an exhaust port of an internal combustion engine for exhaust. And adjacent pipelines are connected through a clamping hoop.

In the embodiment, the pipeline structure comprises the clamp, H is within the range of 0.5R to H, wherein H is less than or equal to R, the rigidity and the strength of the pipe clamp 110 can be increased, the possibility that the pipe clamp part 111 bends and deforms to cause local arching is reduced, and the possibility that the pipeline leaks due to untight sealing at the joint can be further reduced.

Preferably, as shown in fig. 4, the side of the connecting flange 150 away from the sealing gasket 140 is a flange inclined surface. The inclined surface of the flange is inclined to the radial direction of the pipeline. The flange inclined surfaces of the two coupling flanges 150 coupled together form a V-shaped configuration in cross-section (the cross-section extending across the axis of the pipe).

As shown in fig. 3 and 4, the cross-sectional shape of the collar portion 111 (which extends across the axis of the arcuate structure) has a V-shaped groove 116 opening toward the center of the arcuate structure. The V-shaped configuration of the attachment flange 150 enters the V-shaped groove 116. The sides of the V-shaped groove 116 engage and hug the flange inclined plane, and thus the attachment flange 150. This enables the connection flange 150 to be more firmly fixed.

Preferably, the coefficient of linear expansion of the material of the pipe clamp 110 is less than or equal to the coefficient of linear expansion of the material of the coupling flange 150. This makes it possible to avoid as much as possible the occurrence of loosening of the connection between the clip and the connection flange 150 when the connector is operated in a high-temperature environment, and thus to avoid leakage as much as possible.

Second embodiment

In a second embodiment, referring to fig. 5 and 6, the shoulder mounting surface 227 of the shoulder portion 212 is perpendicular to the second radial direction D2 of the pipe clamp portion 211. The clamp also includes a wedge shaped shim 240. The end face of the wedge-shaped shim 240 is inclined to the axial direction of the wedge-shaped shim 240. Thus, the wedge-shaped gasket 240 has a thickness at a first end in a radial direction thereof greater than that at a second end. The wedge washer 240 is fitted around the outer circumference of the screw of the bolt 221. A wedge shim 240 is located between the head of the bolt assembly (the head of bolt 221 and nut 222) and the shoulder mounting surface 227. The first end of the wedge shim 240 is disposed outside of the screw in the first radial direction D1 of the pipe clamp portion 211 (in the first radial direction D1 of the pipe clamp portion 211, the side of the screw away from the center of the arc-shaped structure).

In the case where one end surface of the wedge shim 240 is lapped to the shoulder mounting surface 227, the surface of the wedge shim 240 near the head of the bolt assembly is an inclined surface 231. The operation of the inclined surface 231 is substantially the same as that of the inclined surface 131 of the first embodiment, and will not be described again.

Other configurations of the second embodiment are substantially the same as those of the first embodiment, and are not described herein again.

A clamp is assembled on an exhaust pipe of an internal combustion engine for testing. This test was compared with a first improved clamp and a first test clamp with H ═ 0.1R. The first modified band has an H of 0.6R. The first test clip and the first modified clip were subjected to approximately the same other test conditions. When the internal combustion engine adopting the first test clamp works, the sealing gasket of the exhaust pipe has air leakage. When the internal combustion engine adopting the first improved clamp works, the sealing gasket of the exhaust pipe has no air leakage phenomenon.

In addition, during the test, the contact pressure of the surface of the gasket during operation of the internal combustion engine was collected. With the first improved clamp, the contact pressure of the gasket surface is more uniform in the circumferential direction than with the first test clamp, given the same predetermined pretension force for tightening the bolt, as shown in detail in fig. 7.

A clamp is assembled on an exhaust pipe of an internal combustion engine for testing. This experiment is carried out the experiment with second improvement clamp and the experimental contrast of second clamp. The shoulder mounting surface of the second test clamp was perpendicular to the second radial direction D2 of the pipe clamp portion and the second test clamp was devoid of the wedge shim of the second embodiment. The second improved clamp has the inclined surface of the present application. The other test conditions for the second test clip and the second modified clip were approximately the same. The outer side (the side of the bolt far away from the center of the arc-shaped structure along the first radial direction D1 of the pipe hoop part) and the inner side (the side of the bolt near the center of the arc-shaped structure along the first radial direction D1 of the pipe hoop part) of the screw rod of the bolt are both provided with strain gauges (the strain gauges are positioned between the first clamp and the second clamp). Under the condition that the preset pretightening force for tightening the bolt is the same, when the second improved clamp is adopted, the stress difference between the inner side and the outer side of the bolt is small and the material yield is not exceeded. When the second test clamp is used, the stress difference between the stresses on the inner side and the outer side of the bolt is large (up to 200MPa or more), and the difference is increased along with the gradual increase of the preset pretightening force, as shown in fig. 8 in detail, wherein the bolt 1 and the bolt 2 are two bolts for connecting the clamp.

The present invention has been illustrated by the above embodiments, but it should be understood that the above embodiments are for illustrative and descriptive purposes only and are not intended to limit the invention to the scope of the described embodiments. Furthermore, it will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that many variations and modifications may be made in accordance with the teachings of the present invention, which variations and modifications are within the scope of the present invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Terms such as "component" and the like, when used herein, can refer to either a single part or a combination of parts. Terms such as "mounted," "disposed," and the like, as used herein, may refer to one component being directly attached to another component or one component being attached to another component through intervening components. Features described herein in one embodiment may be applied to another embodiment, either alone or in combination with other features, unless the feature is otherwise inapplicable or otherwise stated in the other embodiment.

The present invention has been described in terms of the above embodiments, but it should be understood that the above embodiments are for purposes of illustration and description only and are not intended to limit the invention to the scope of the described embodiments. It will be appreciated by those skilled in the art that many variations and modifications may be made to the teachings of the invention, which fall within the scope of the invention as claimed.

Claims

1. A clamp, comprising:

the pipe hoop comprises two pipe hoops and a convex shoulder part, the pipe hoop part is of an arc structure, the convex shoulder part is arranged at two ends of the pipe hoop part along a first radial direction of the pipe hoop part, the convex shoulder part is provided with an installation through hole of which the axis extends along a second radial direction of the pipe hoop part, the second radial direction is perpendicular to the first radial direction, the size of the convex shoulder part along the second radial direction of the pipe hoop part is H, the radius size of the pipe hoop part is R, the range of H is more than or equal to 0.5R and less than or equal to H and less than or equal to R,

the bolt assembly comprises a bolt and a nut, and the bolt is used for being connected with the nut after penetrating through the installation through hole so as to connect the two pipe hoops.

2. The clamp of claim 1, wherein the shoulder mounting surface of the shoulder portion proximate the head portion of the bolt assembly is an inclined surface having an outer inclined surface end and an inner inclined surface end, the outer inclined surface end being located on a side of the inner inclined surface end distal from a center of the arcuate structure in a first radial direction of the band portion, and the inner inclined surface end being located on a side of the outer inclined surface end proximal to the center of the arcuate structure in a second radial direction of the band portion.

3. The clamp of claim 1, wherein a shoulder mounting surface of the shoulder portion adjacent to the head portion of the bolt assembly is perpendicular to the second radial direction of the pipe clamp portion, the clamp includes a wedge-shaped spacer, and when the bolt assembly connects two pipe clamps, the wedge-shaped spacer is sleeved on the screw of the bolt, and the wedge-shaped spacer is overlapped on the shoulder mounting surface, so that a surface of the wedge-shaped spacer adjacent to the head portion of the bolt assembly is an inclined surface.

4. Clamp according to claim 2 or 3, wherein the angle α between the inclined surface and the first radial direction of the band portion is in the range 0 ° < α ≦ 20 °.

5. The clamp of claim 1, wherein the coefficient of linear expansion of the material of the bolt is less than or equal to the coefficient of linear expansion of the material of the pipe clamp.

6. Clamp according to claim 1,

The coefficient of linear expansion of the material of the pipe clamp is less than or equal to 17.

7. The clamp of claim 1, wherein the cross-sectional shape of the band portion has a V-shaped groove.

8. A pipe structure for an internal combustion engine, characterized by comprising: at least two pipes, and a clamp according to any one of claims 1 to 7 for connecting adjacent said pipes.

9. The piping structure of claim 8, wherein the ends of the pipes are provided with connection flanges, and the pipe clamp is used for connecting the connection flanges of the adjacent pipes to connect the adjacent pipes, and further comprising a sealing gasket for being arranged between the connection flanges of the adjacent pipes to seal a gap between the connection flanges of the adjacent pipes, and the material of the pipe clamp has a coefficient of linear expansion smaller than or equal to that of the connection flanges.