Thermal expansion sealing structure for bolt installation of exhaust pipe
By using a combination of sleeves and bolts between the exhaust pipe flange and the engine cylinder head, the problem of thermal stress release in the exhaust manifold is solved, a stable connection between the exhaust pipe and the cylinder head is achieved, and the service life and operating efficiency of the engine are improved.
Patent Information
- Application Number
- CN202520142195.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-21
- Publication Date
- 2025-11-18
- Estimated Expiration
- 2035-01-21
AI Technical Summary
The thermal stress on the flange surface between the exhaust manifold and the engine cylinder head cannot be released, causing the exhaust manifold to deform, which affects the cylinder head surface and engine performance.
The system employs a combination of sleeve and bolts. The sleeve is fitted inside the flange hole, and the bolt passes through the sleeve to connect to the engine cylinder head, forming an expansion gap to release thermal stress and isolating the flange surface from the effects of expansion or contraction through the sleeve.
It effectively avoids exhaust manifold deformation, prevents gasket slippage, improves connection strength and engine operating efficiency, reduces the impact of bolt thermal stress, and ensures bolt fastening reliability.
Smart Images
Figure CN223562907U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to the technical field of engine, concretely relates to a heat expansion sealing structure of exhaust pipe bolt installation. BACKGROUND
[0002] The exhaust pipe comprises a head section, a middle section and a tail section; the exhaust manifold is connected to the cylinder head of the engine as the head section; the exhaust manifold is a pipeline with a manifold, which is used for concentrating the exhaust of each cylinder into the supercharger or the exhaust pipe.
[0003] At present, one end of the exhaust manifold is connected with a flange, and the flange is fixedly connected with the engine cylinder head through the bolt penetrating the flange, and the flange end surface is completely attached to the engine cylinder head. When the engine load is high, the engine runs at a high speed, and the temperature rises, so that the engine exhaust temperature rises. Since the flange end surface is completely attached to the engine cylinder head, that is, the exhaust manifold compresses the exhaust pipe gasket, when the heat is transferred to the exhaust manifold, the thermal stress of the different flange surfaces connected by the exhaust manifold cannot be released, thereby causing the deformation of the exhaust manifold and the exhaust pipe, and the gasket between the exhaust manifold and the engine cylinder head is affected by the deformation of the exhaust manifold and rubs the cylinder head surface back and forth, which causes the cylinder head surface to be bitten and even deformed. Not only does it affect the service life of the exhaust manifold and even the entire exhaust pipe, but also it affects the use performance of the engine cylinder head and even the engine. CONTENT
[0004] The utility model provides a kind of heat expansion sealing structure of exhaust pipe bolt installation, to solve the thermal stress of the different flange surfaces connected by the exhaust manifold cannot be released, thereby causing the deformation of the exhaust manifold, and the gasket between the exhaust manifold and the engine cylinder head is affected by the deformation of the exhaust manifold and rubs the cylinder head surface back and forth, which causes the cylinder head surface to be bitten and even deformed.
[0005] The technical scheme adopted by the utility model is as follows:
[0006] A kind of heat expansion sealing structure of exhaust pipe bolt installation, comprising:
[0007] Exhaust pipe flange is connected to exhaust manifold;The exhaust pipe flange is provided with a plurality of flange holes;
[0008] Connecting assembly, including gasket, bolt and sleeve;The gasket is connected between the exhaust pipe flange and the engine cylinder head;The sleeve is sleeved in the flange hole, the bolt is sleeved in the sleeve, and the bolt is connected with the engine cylinder head after being stretched into the engine cylinder head from the bottom of the flange hole;
[0009] The sleeve forms a boss, and a side of the boss facing the engine cylinder cover forms a stepped surface for abutting a first end surface of the exhaust pipe flange; an end portion of the sleeve extending out of the flange hole and abutting the gasket to form an expansion gap between the second end surface of the exhaust pipe flange and the engine cylinder cover.
[0010] The exhaust pipe bolt mounting thermal expansion sealing structure also has the following additional technical features:
[0011] The flange hole is a stepped hole having a larger diameter end and a smaller diameter end; the smaller diameter end is located at the end of the flange hole, and the larger diameter end is located at the first end surface of the exhaust pipe flange; the larger diameter end forms a stepped end surface that can abut the stepped surface.
[0012] The radial dimension of the stepped end surface is greater than the radial dimension of the sleeve.
[0013] The sleeve includes a first segment and a second segment connected together; the first segment is sleeved in the flange hole, and the second segment is disposed outside the flange hole.
[0014] The radial dimension of the second segment is greater than the radial dimension of the first segment, so that the boss is formed between the first segment and the second segment.
[0015] An end of the first segment extending out of the flange hole abuts the gasket.
[0016] The first segment has a heat transfer gap between the outer periphery and the side wall of the flange hole.
[0017] The bolt includes a screw head and a screw rod connected together; the screw rod can extend into the engine cylinder cover and connect with the engine cylinder cover after passing through the first segment and the second segment; and the screw head can abut the bottom of the second segment.
[0018] The engine cylinder cover is provided with a connecting hole corresponding to the flange hole, so that the bolt passes through the flange hole and connects to the connecting hole.
[0019] The linear expansion coefficient of the sleeve is the same as that of the bolt, and the linear expansion coefficient of the sleeve is smaller than that of the exhaust pipe flange.
[0020] Due to the adoption of the above technical solutions, the utility model has the following beneficial effects:
[0021] 1. The application relates to a bolt mounting heat expansion sealing structure of an exhaust pipe, which comprises an exhaust pipe flange and a connecting assembly, wherein the exhaust pipe flange is connected to the end of an exhaust manifold, a flange hole is formed in the exhaust pipe flange, the exhaust manifold is connected to an engine cylinder cover by connecting bolts to the engine cylinder cover through the flange hole, so that the exhaust pipe is connected to the engine cylinder cover; the connecting assembly comprises a gasket, bolts and a sleeve, the gasket is connected between the exhaust pipe flange and the engine cylinder cover; the sleeve is sleeved in the flange hole, the bolts are sleeved in the sleeve, the bolts are connected to the engine cylinder cover after penetrating out of the sleeve, one end of the sleeve, which is sleeved in the flange hole, extends out of the flange hole and abuts against the gasket, so that an expansion space is formed between the second end surface of the exhaust pipe flange and the engine cylinder cover; when the exhaust temperature of the engine rises, the exhaust manifold has a certain expansion space due to the existence of the expansion gap, so that the thermal stress of different flange surfaces of the exhaust pipe flange connected to the exhaust manifold is effectively released, deformation of the exhaust manifold and even the exhaust pipe is avoided, the gasket between the exhaust pipe flange and the engine cylinder cover is prevented from rubbing the cylinder cover surface back and forth, the cylinder cover surface is prevented from being bitten and even deformed, the connecting strength between the exhaust pipe and the engine cylinder cover is effectively improved, and the operation efficiency of the exhaust pipe and the engine is effectively improved.
[0022] In addition, the sleeve can isolate the flange hole and the bolts, the expansion or contraction of the flange surface caused by the change of the exhaust temperature will not affect the deformation of the bolts due to the isolation of the sleeve, the loosening of the bolts connected between the exhaust manifold and the engine cylinder cover is prevented, the connecting strength between the entire engine cylinder cover and the entire exhaust pipe is improved; and the heat transfer route of heat is from the engine cylinder cover, through the exhaust pipe, through the sleeve and then to the bolts, so that the bolts are less affected by the thermal stress and the temperature of the bolts is reduced, the purpose of heat insulation and cooling is achieved, the bolt fastening reliability is ensured, and the axial force of the bolts is improved.
[0023] 2. As a preferred embodiment of the utility model, the flange hole is a stepped hole, the stepped hole has one end with a larger diameter and one end with a smaller diameter; the one end with a smaller diameter is located at the end of the flange hole, and the one end with a larger diameter is located at the first end surface of the exhaust pipe flange; the one end with a larger diameter is formed with a stepped end surface, and the stepped end surface can abut against the stepped surface. Since the sleeve has a boss, the stepped surface of the boss abuts against and connects to the stepped end surface formed by the one end with a larger diameter, so that the positioning of the sleeve in the flange hole is realized, and the positioning of the bolts is further realized after the positioning of the sleeve.
[0024] 3. As a preferred embodiment of the utility model, the radial dimension of the stepped end surface is larger than the radial dimension of the sleeve. The purpose of the radial dimension of the stepped end surface being larger than the radial dimension of the sleeve is that the stepped surface of the sleeve can abut against and connect to the stepped end surface.
[0025] 4. In a preferred embodiment of this utility model, the sleeve includes a first section and a second section connected together; the first section is fitted inside the flange hole, and the second section is disposed outside the flange hole. The first section can be inserted from the first end face of the exhaust pipe flange to the second end face of the exhaust pipe flange, and then the end of the first section not connected to the second section can partially protrude outside the flange hole. The length of the protruding part is calculated according to the thermal expansion of the exhaust manifold. The end of the first section not connected to the second section can abut against the gasket; the second section is fixedly connected to the first section in an integrated structure. The top of the second section has a stepped surface that can abut against the stepped end face of the flange hole on the first end face of the exhaust pipe flange, so that the second section is disposed outside the flange hole of the exhaust pipe flange. The bottom end face of the second section can abut against the end face of the bolt head, thereby realizing the positioning of the bolt in the sleeve.
[0026] 5. In a preferred embodiment of this utility model, one end of the first section extending beyond the flange hole abuts against the gasket. The top end of the first section can extend beyond the second end face of the exhaust pipe flange and abut against the gasket, thereby achieving a reserved expansion gap between the top end face of the first section and the second end face of the exhaust pipe flange. Attached Figure Description
[0027] The accompanying drawings, which are included to provide a further understanding of the present invention and constitute a part of this invention, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings:
[0028] Figure 1 This is a schematic diagram of the overall structure of a thermal expansion sealing structure for an exhaust pipe bolt mounting according to one embodiment of this application;
[0029] Figure 2 This is a partially enlarged schematic diagram showing the connection between the bolt, sleeve, gasket, exhaust pipe, and engine cylinder head in one embodiment of this application, representing the connection between the bolt, sleeve, gasket, exhaust pipe, and engine cylinder head in a thermal expansion sealing structure for an exhaust pipe bolt mounting.
[0030] Figure 3 for Figure 2 A magnified view of a section at point A in the middle;
[0031] In the picture,
[0032] 1. Engine cylinder head; 2. Exhaust pipe flange; 3. Connecting assembly; 31. Gasket; 32. Bolt; 321. Threaded head; 322. Threaded rod; 33. Sleeve; 331. First section; 332. Second section; 4. Stepped surface; 5. Stepped end face; 6. Expansion gap; 7. First end face of exhaust pipe flange; 8. Second end face of exhaust pipe flange; 9. Heat transfer gap. DETAILED DESCRIPTION
[0033] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one skilled in the art that the present application can be practiced without the specific details set forth in this description.
[0034] In addition, in the description of the present application, it needs to be understood that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.
[0035] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection, or communication; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0036] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. In the description of the present application, the description of the terms "embodiment", "example", "one embodiment", "exemplary" or "specific example" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.
[0037] In order to more clearly illustrate the overall concept of the present application, the following will be described in detail with reference to the accompanying drawings.
[0038] The present application relates to a kind of exhaust pipe bolt installation thermal expansion sealing structure, such as Figures 1-3As shown, a component for connecting an exhaust pipe to an engine cylinder head 1 includes: an exhaust pipe flange 2 connected to an exhaust manifold; the exhaust pipe flange 2 has multiple flange holes; a connecting assembly 3 including a gasket 31, a bolt 32, and a sleeve 33; the gasket 31 is connected between the exhaust pipe flange 2 and the engine cylinder head 1; the sleeve 33 is fitted into the flange holes, the bolt 32 is fitted into the sleeve 33, and the bolt 32 passes through the bottom of the flange hole and extends into the engine cylinder head 1 to connect with the engine cylinder head 1; the sleeve 33 has a boss, and the side of the boss facing the engine cylinder head 1 has a stepped surface 4 for abutting against the first end face 7 of the exhaust pipe flange; one end of the sleeve 33 fitted into the flange hole extends out of the flange hole and abuts against the gasket 31, so that an expansion gap 6 is formed between the engine cylinder head 1 and the second end face 8 of the exhaust pipe flange.
[0039] The exhaust pipe includes a header, a middle section, and a tail section. The exhaust manifold, as the header section, connects to the engine cylinder head 1. The exhaust manifold is a pipe with manifolds used to collect exhaust gases from each cylinder and guide them into the turbocharger or exhaust pipe. The exhaust pipe flange 2 connects to the end of the exhaust manifold. The exhaust pipe flange 2 has flange holes, and bolts 32 are passed through the flange holes and connected to the engine cylinder head 1, thus connecting the exhaust manifold to the engine cylinder head 1, and consequently, the exhaust pipe to the engine cylinder head 1.
[0040] like Figure 1 For ease of description, the bottom end face of the exhaust pipe flange 2 is marked as the first end face 7 of the exhaust pipe flange; the top end face of the exhaust pipe flange 2 is marked as the second end face 8 of the exhaust pipe flange. The bottom end of the flange hole is marked as the end with the larger diameter, and the top end of the flange hole is marked as the end with the smaller diameter.
[0041] When the engine load is high, the engine runs at a high speed, the temperature rises, the engine exhaust temperature rises, and because the end face of the exhaust pipe flange 2 is completely attached to the engine cylinder head 1, that is, the end face of the exhaust pipe flange 2 is pressed against the gasket 31, causing heat to be transferred to the exhaust manifold, so that the thermal stress of the different flange faces of the exhaust manifold connected to the exhaust pipe flange 2 cannot be released, thereby causing the exhaust manifold to deform, and even the exhaust pipe, the gasket 31 between the exhaust pipe flange 2 and the engine cylinder head 1 is affected by the deformation of the exhaust manifold and rubs the engine cylinder head face back and forth, causing the engine cylinder head face to be gnawed or even deformed. Therefore, the connecting assembly 3 involved in the present application includes a gasket 31, a bolt 32 and a sleeve 33, the gasket 31 is connected between the exhaust pipe flange 2 and the engine cylinder head 1; the sleeve 33 is sleeved in the flange hole, the bolt 32 is sleeved in the sleeve 33, the bolt 32 extends into the engine cylinder head 1 after passing out of the sleeve 33 and is connected with the engine cylinder head 1; by providing a sleeve 33 in the flange hole, the sleeve 33 can isolate the flange hole and the bolt 32, the expansion or contraction of the flange face caused by the change of exhaust temperature will not affect the deformation of the bolt 32, preventing the bolt 32 connected between the exhaust manifold and the engine cylinder head 1 from loosening, thereby improving the connection strength between the entire engine cylinder head 1 and the entire exhaust pipe; and, the heat transfer route of heat is from the engine cylinder head 1, through the exhaust pipe, then through the sleeve 33 and then to the bolt 32, thereby reducing the direct effect of thermal stress on the bolt 32, reducing the temperature of the bolt 32, achieving the purpose of heat insulation and cooling, thereby ensuring the fastening reliability of the bolt 32 and improving the axial force of the bolt 32.
[0042] In addition, the sleeve 33 is designed to have a structure with a boss, the side of the boss facing the engine cylinder head 1 is formed with a stepped surface 4 for abutting the first end face 7 of the exhaust pipe flange; one end portion of the sleeve 33 extending out of the flange hole, as shown in Figure 3 the drawing, so that an expansion gap 6 is formed between the end face of the end of the sleeve 33 extending out of the flange hole and the second end face 8 of the exhaust pipe flange, so that the second end face 8 of the exhaust pipe flange and the engine cylinder head 1 have an expansion space; when the engine exhaust temperature rises, the exhaust manifold has a certain expansion space, so that the thermal stress of the different flange faces of the exhaust manifold connected to the exhaust pipe flange 2 is effectively released, avoiding the deformation of the exhaust manifold and even the exhaust pipe, thereby avoiding the back and forth rubbing of the gasket 31 between the exhaust pipe flange 2 and the engine cylinder head 1 on the engine cylinder head face, thereby avoiding the gnawing or even deformation of the engine cylinder head face, which not only effectively improves the connection strength between the exhaust pipe and the engine cylinder head 1, but also effectively improves the operating efficiency of the exhaust pipe and the engine.
[0043] As a preferred embodiment, the flange hole is a stepped hole having a larger diameter end and a smaller diameter end; the smaller diameter end is located at the end of the flange hole, and the larger diameter end is located at the first end surface 7 of the exhaust pipe flange; the larger diameter end forms a stepped end surface 5 which can abut against the stepped surface 4.
[0044] The flange hole is provided as a stepped hole, the smaller diameter end is located at the end of the flange hole, and the larger diameter end is provided at the first end surface 7 of the exhaust pipe flange, which can be used to install the sleeve 33, the sleeve 33 includes the first section 331 and the second section 332 described below, the first section 331 and the second section 332 form a boss, the first section 331 of the sleeve 33 is sleeved in the flange hole, the stepped surface 4 formed by the boss abuts and connects with the stepped end surface 5 formed by the larger diameter end, so that the second section 332 of the sleeve is located outside the flange hole, thereby achieving the positioning of the sleeve 33 in the flange hole, and the sleeve 33 can further realize the positioning of the bolt 32. In use, the sleeve 33 is sleeved in the exhaust pipe flange 2, the stepped surface 4 of the sleeve 33 abuts against the stepped end surface 5 of the flange hole, thereby achieving the positioning of the exhaust pipe flange 2, then the gasket 31 is provided on the engine cylinder head 1, and then the exhaust pipe flange 2 and the sleeve 33 are installed on the engine cylinder head 1, the end of the sleeve 33 abuts and connects to the gasket 31, and then the bolt 32 is inserted into the engine cylinder head 1 to connect with the engine cylinder head 1 through the sleeve 33 and the gasket 31, thereby achieving the connection between the engine cylinder head 1 and the exhaust manifold. Since the first section 331 of the sleeve 33 can extend out of the flange hole, the top end surface of the first section 331 of the sleeve 33 and the second end surface 8 of the exhaust pipe flange have an expansion gap 6, which allows the second end surface 8 of the exhaust pipe flange to form an expansion space for thermal deformation with the engine cylinder head 1, thereby providing an expansion space for the exhaust manifold after being heated and expanded, so as not to affect the gasket 31, avoiding the gasket 31 from being rubbed back and forth under the influence of thermal stress, thereby avoiding the surface of the engine cylinder head 1 from being damaged by rubbing, and improving the service life of the entire exhaust pipe and the engine.
[0045] Further, the radial dimension of the stepped end surface 5 is greater than the radial dimension of the sleeve 33.
[0046] The purpose of the radial dimension of the stepped end surface 5 being greater than the radial dimension of the sleeve 33 is to facilitate the abutting connection of the stepped surface 4 of the sleeve 33 to the stepped end surface 5.
[0047] As a preferred embodiment, the sleeve 33 includes a first section 331 and a second section 332 connected to each other; the first section 331 is sleeved in the flange hole, and the second section 332 is provided outside the flange hole.
[0048] As shown in the drawings, Figure 1In the shown orientation, the first section 331 of the sleeve 33 is positioned above, the second section 332 of the sleeve 33 is positioned below, the first section 331 can be inserted from the first end surface 7 of the exhaust pipe flange to the second end surface 8 of the exhaust pipe flange, and then the end of the first section 331 not connected with the second section 332 can partially extend out of the flange hole, that is Figure 1 In the shown orientation, the top end of the first section 331 extends out of the flange hole, and the length of the extending part of the first section 331 is calculated according to the amount of thermal expansion of the exhaust manifold, the end of the first section 331 not connected with the second section 332, that is, the top end of the first section 331, can abut against the gasket 31; the second section 332 is fixedly connected with the first section 331 in an integrated structure, the top of the second section 332 has a stepped surface 4 which can abut against and connect with the stepped end surface 5 of the flange hole, so that the second section 332 is arranged outside the flange hole of the exhaust pipe flange 2, and the bottom end surface of the second section 332 can abut against and connect with the end surface of the screw head 321 of the bolt 32, thereby realizing the positioning of the bolt 32 in the sleeve 33.
[0049] Further, the radial dimension of the second section 332 is greater than the radial dimension of the first section 331, so that a boss is formed between the first section 331 and the second section 332.
[0050] As Figure 1 shown, the radial dimension of the second section 332 of the sleeve 33 is greater than the radial dimension of the first section 331, so that the sleeve 33 has a stepped shaft structure, a boss is formed between the first section 331 and the second section 332, the end surface of the end of the second section 332 connected with the first section 331 has a stepped surface 4 which can abut against and connect with the stepped end surface 5 of the flange hole, thereby realizing the positioning and installation of the second section 332 of the sleeve 33. In use, the first section 331 of the sleeve 33 is sleeved in the flange hole of the exhaust pipe flange 2 until the stepped surface 4 of the second section 332 of the sleeve 33 abuts against and connects with the stepped end surface 5, thereby realizing the positioning of the sleeve 33, the first section 331 of the sleeve 33 extends out of the second end surface 8 of the exhaust pipe flange and abuts against the gasket 31, thereby realizing that the second end surface 8 of the exhaust pipe flange and the gasket 31 have a preset expansion gap 6.
[0051] Further, the end of the first section 331 extending out of the flange hole abuts against the gasket 31.
[0052] As Figure 1 shown, the first section 331 is sleeved in the flange hole, the top end of the first section 331 can extend out of the second end surface 8 of the exhaust pipe flange and abut against the gasket 31, thereby realizing that the end surface of the top end of the first section 331 and the second end surface 8 of the exhaust pipe flange have a reserved expansion gap 6.
[0053] Furthermore, a heat transfer gap 9 exists between the outer periphery of the first section 331 and the sidewall of the flange hole.
[0054] In order to reserve a heat transfer gap 9 so that the heat of the exhaust pipe can be transferred out in the flange hole of the exhaust pipe flange 2, a heat transfer gap 9 is formed between the inner wall of the flange hole and the outer peripheral surface of the first section 331. This allows the heat to be conducted out, thereby reducing the temperature of the bolt 32 installed inside the sleeve 33, thus ensuring the fastening reliability of the bolt 32 and improving the axial force of the bolt 32.
[0055] In a preferred embodiment, the bolt 32 includes a threaded head 321 and a threaded rod 322 connected together; the threaded rod 322 can pass through the first section 331 and the second section 332 and extend into the engine cylinder head 1 to connect with the engine cylinder head 1; the threaded head 321 can abut against the bottom of the second section 332.
[0056] like Figure 1 As shown, the bolt head 321 of bolt 32 is located at the bottom, and the screw 322 is connected above the bolt head 321. The screw 322 can be inserted into the sleeve 33 and then inserted into the engine cylinder head 1 after passing through the sleeve 33, so as to realize the fixed connection between the exhaust manifold and the engine cylinder head 1. The end face of the bolt head 321 can abut against the bottom end face of the second section 332 of the sleeve 33, thereby realizing the positioning and installation of bolt 32. After bolt 32 is installed, an expansion gap 6 is formed between the top end of the first section 331 of the sleeve 33 and the second end face 8 of the exhaust pipe flange.
[0057] In a preferred embodiment, the engine cylinder head 1 has a connection hole corresponding to the flange hole, so that the bolt 32 passes through the flange hole and connects to the connection hole.
[0058] The engine cylinder head 1 has a connection hole that corresponds to the flange hole, so that the bolt 322 can be inserted into the connection hole of the engine cylinder head 1 after passing through the sleeve 33 and fixedly connected to the engine cylinder head 1.
[0059] In a preferred embodiment, the sleeve 33 and the bolt 32 have the same coefficient of linear expansion, but the coefficient of linear expansion of the sleeve 33 is less than that of the exhaust pipe flange 2.
[0060] Sleeve 33 is a metal sleeve. Preferably, sleeve 33 can be made of the same material as bolt 32, using a material with a small coefficient of linear expansion. However, sleeve 33 cannot be made of the same material as exhaust pipe flange 2. Exhaust pipe flange 2 generally uses a material with a large coefficient of linear expansion. It is precisely by utilizing the small coefficient of linear expansion of sleeve 33 that bolt 32 can always be tightened on sleeve 33 when hot.
[0061] For any parts not mentioned in this utility model, existing technologies can be used or referenced.
[0062] The various embodiments in the specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the difference from other embodiments.
[0063] The above only describes the embodiments of the present application and is not intended to limit the present application. The present application can be variously changed and modified by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of the claims of the present application.
Claims
1. An exhaust pipe bolt-on thermal expansion seal structure, characterized by, The utility model relates to an exhaust pipe flange (2) connected to an exhaust manifold, wherein the exhaust pipe flange (2) is provided with a plurality of flange holes; a connecting assembly (3) comprising a gasket (31), a bolt (32) and a sleeve (33), wherein the gasket (31) is connected between the exhaust pipe flange (2) and an engine cylinder head (1), the sleeve (33) is sleeved in the flange hole, the bolt (32) is sleeved in the sleeve (33), the bolt (32) is connected to the engine cylinder head (1) after being passed out from the bottom of the flange hole; the sleeve (33) is provided with a boss, and the boss is provided with a stepped surface (4) for abutting against a first end surface (7) of the exhaust pipe flange, and the end of the sleeve (33) that is sleeved in the flange hole is extended out of the flange hole and abuts against the gasket (31) so as to form an expansion gap (6) between the engine cylinder head (1) and a second end surface (8) of the exhaust pipe flange. The flange hole is a stepped hole with a larger-diameter end and a smaller-diameter end, the smaller-diameter end is located at the end of the flange hole, the larger-diameter end is located at the first end surface (7) of the exhaust pipe flange, the larger-diameter end is provided with a stepped end surface (5) that can abut against the stepped surface (4). The radial dimension of the stepped end surface (5) is larger than the radial dimension of the sleeve (33). The sleeve (33) comprises a first section (331) and a second section (332) connected to each other, the first section (331) is sleeved in the flange hole, and the second section (332) is arranged outside the flange hole.
2. An exhaust pipe bolt-on thermal expansion seal structure according to claim 1, wherein, The radial dimension of the second section (332) is larger than the radial dimension of the first section (331) so as to form a boss between the first section (331) and the second section (332).
3. An exhaust pipe bolt-on thermal expansion seal structure according to claim 2, wherein, The bolt (32) comprises a screw head (321) and a screw rod (322) connected to each other, the screw rod (322) can be passed through the first section (331) and the second section (332) and then extended into the engine cylinder head (1) to be connected to the engine cylinder head (1), and the screw head (321) can abut against the bottom of the second section (332).
4. A bolted expansion seal for an exhaust pipe according to claim 1, wherein, The end of the first section (331) that is extended out of the flange hole abuts against the gasket (31).
5. An exhaust pipe bolt-on thermal expansion seal structure according to claim 4, wherein, The outer periphery of the first section (331) has a heat transfer gap (9) with the side wall of the flange hole.
6. A bolted expansion seal for an exhaust pipe according to claim 4, wherein, The engine cylinder head (1) is provided with a connecting hole corresponding to the flange hole so that the bolt (32) is connected to the connecting hole through the flange hole.
7. A bolted expansion seal for an exhaust pipe according to claim 4, wherein, The sleeve (33) and the bolt (32) have the same linear expansion coefficient, and the linear expansion coefficient of the sleeve (33) is smaller than the linear expansion coefficient of the exhaust pipe flange (2).
8. A bolted expansion seal for an exhaust pipe according to claim 4, wherein, 9. A bolted expansion seal for an exhaust pipe according to claim 1 wherein, 10. A bolted expansion seal for an exhaust pipe according to claim 1, wherein,