Exhaust pipe insulation structure

Abstract

To provide a heat insulation structure of an exhaust pipe which can inhibit heat damage from occurring in a rubber member serving as a hanging point of an exhaust pipe.SOLUTION: A heat insulation structure 1 of an exhaust pipe is a structure connected to an internal combustion engine of a vehicle and includes: an exhaust pipe 10; heat insulators 20, 30 which cover the exhaust pipe 10; and a bracket 60 which is attached with a rubber member D serving as a hanging point of the exhaust pipe 10 on the vehicle. The heat insulator 20 has an opening 35 which exposes the exhaust pipe 10. The opening 35 is mounted with a foundation part 70 of the bracket 60 so that a heat insulation layer 80 is formed between the exhaust pipe 10 and the bracket 60.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a thermal insulation structure for an exhaust pipe. [Background technology]

[0002] An example of a conventional exhaust pipe insulation structure is an exhaust pipe with an exhaust gas insulation structure described in Patent Document 1. In this conventional exhaust pipe insulation structure, the exhaust pipe is divided into multiple parts in the exhaust gas flow direction, and a protective shield member is provided to cover the outer periphery of the joints. One end of the protective shield member is fixed to the downstream heat insulator, while the other end of the protective shield member is not fixed to the upstream heat insulator. An overlapping portion having a predetermined gap is provided between the inner periphery of the protective shield member and the outer periphery of the upstream heat insulator. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-39325 A Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned exhaust pipe may be provided with a bracket for mounting the exhaust pipe to the vehicle. In this case, a rubber member that serves as a suspension point of the exhaust pipe to the vehicle is attached to the bracket. However, since high-temperature exhaust gas flows through the exhaust pipe, the exhaust pipe itself becomes hot. Therefore, it is necessary to devise a method for preventing heat damage to the rubber member that serves as the suspension point of the exhaust pipe.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide an insulating structure for an exhaust pipe that can prevent thermal damage to the rubber member that serves as the suspension point of the exhaust pipe. [Means for solving the problem]

[0006] An insulating structure for an exhaust pipe according to one aspect of the present disclosure is an insulating structure for an exhaust pipe connected to an internal combustion engine of a vehicle, and includes an exhaust pipe, a heat insulator covering the exhaust pipe, and a bracket to which a rubber member serving as a hanging point for the exhaust pipe to the vehicle is attached, the heat insulator having an opening to expose the exhaust pipe, and a base portion of the bracket is provided in the opening so that an insulating layer is formed between the exhaust pipe and the bracket.

[0007] In this exhaust pipe insulation structure, the base of the bracket forms an insulation layer between the exhaust pipe and the bracket. This makes it possible for the insulation layer to block heat from reaching the bracket even if the exhaust pipe itself becomes hot due to high-temperature exhaust gas. This makes it possible to prevent heat damage to the rubber member that serves as the suspension point for the exhaust pipe.

[0008] The exhaust pipe has a protruding region that protrudes due to bending or swelling of the exhaust pipe, and the heat insulator is composed of a first heat insulator that covers the exhaust pipe upstream of the protruding region and a second heat insulator that covers the exhaust pipe downstream of the protruding region, and the base is disposed in an opening provided in the second heat insulator. In this case, it is possible to support the exhaust pipe in a well-balanced manner via the bracket.

[0009] The heat insulating layer may be sealed by the exhaust pipe and the base, which can prevent foreign matter from entering the heat insulating layer and coming into contact with high-temperature parts such as the exhaust pipe.

[0010] The opening and base may be located above the exhaust pipe when the exhaust pipe is attached to the vehicle. In this case, the bracket can improve access to the rubber member that serves as the suspension point for the exhaust pipe. Also, compared to when the opening and base are located below the exhaust pipe, the area around the opening and base can be prevented from being exposed to foreign matter such as dead grass.

[0011] A wire mesh may be disposed in the gap between the exhaust pipe and the heat insulator at the opening, thereby preventing foreign matter such as dead grass from entering the inside of the heat insulator from the outside. Effect of the Invention

[0012] According to the present disclosure, it is possible to suppress thermal damage to the rubber member that serves as the suspension point of the exhaust pipe. [Brief description of the drawings]

[0013] [Figure 1] 1 is a side view showing a heat insulating structure of an exhaust pipe according to an embodiment of the present disclosure. [Diagram 2] 2 is a partially enlarged perspective view of the heat insulating structure of the exhaust pipe shown in FIG. 1. [Diagram 3] 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] 2 is a perspective view showing the heat insulating structure of the exhaust pipe shown in FIG. 1 with a heat insulator removed. FIG. [Diagram 5] 2 is an enlarged cross-sectional view of a main part of the heat insulating structure of the exhaust pipe shown in FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, a preferred embodiment of a thermal insulation structure for an exhaust pipe according to one aspect of the present disclosure will be described in detail with reference to the drawings.

[0015] A preferred embodiment of a heat insulating structure for an exhaust pipe according to one aspect of the present disclosure will be described in detail below with reference to the drawings. In the following description, for convenience of explanation, the terms "upper" and "lower" are used based on the installation state of the exhaust pipe to the vehicle. In addition, the terms "upper" and "downstream" are used based on the flow direction of exhaust gas in the exhaust pipe.

[0016] 1 is a side view showing an exhaust pipe insulation structure according to an embodiment of the present disclosure. As shown in the figure, the exhaust pipe insulation structure 1 is a structure that insulates an exhaust pipe 10 with a first heat insulator 20 and a second heat insulator 30. The exhaust pipe 10 has a protruding region 19 that protrudes vertically downward due to bending or swelling of the exhaust pipe 10. The first heat insulator 20 is disposed so as to cover the exhaust pipe 10 upstream of the protruding region 19. The second heat insulator 30 is disposed so as to cover the exhaust pipe 10 downstream of the protruding region 19.

[0017] The exhaust pipe 10 is connected to an internal combustion engine mounted on a vehicle, and constitutes an exhaust passage that discharges exhaust gas generated by combustion in a combustion chamber of the internal combustion engine. When connected to the internal combustion engine, the exhaust pipe 10 extends, for example, along the front-rear direction of the vehicle. An example of an internal combustion engine is a diesel engine. Examples of vehicles to which the exhaust pipe insulation structure 1 is applied include passenger cars, pickup trucks, buses, dump trucks, and the like.

[0018] On the upstream side of the exhaust pipe 10, for example, a turbocharger, a DOC (Diesel Oxidation Catalyst), a DPF (Diesel Particulate Filter), etc. are provided. On the downstream side of the exhaust pipe 10, for example, an SCR (Selective Catalytic Reduction) is provided. In the example of FIG. 1, an injector 50 for injecting a reducing agent (e.g., urea water) into the SCR is disposed in the exhaust pipe 10. The injector 50 is attached to the wall of the exhaust pipe 10 so as to face the upstream side of the exhaust pipe 10. In addition, on the downstream side of the exhaust pipe 10, a bracket 60 and a base part 70 used for mounting the exhaust pipe 10 to a vehicle are provided. The configurations of the bracket 60 and the base part 70 will be described later.

[0019] The exhaust pipe 10 has a connection part 11 on the upstream side and bent parts 12, 13, and 14. Another exhaust pipe arranged on the upstream side (internal combustion engine side) of the exhaust pipe 10 is connected to the connection part 11. A straight part 15 extending from the connection part 11 is inclined downward toward the injector 50 to match the piping path of the upstream exhaust pipe. The bent part 12 bends the exhaust pipe 10 such that the inclination of a straight part 16 extending downstream from the bent part 12 is smaller than the inclination of the straight part 15. The extension direction of the straight part 15 downstream of the bent part 12 is more aligned with the direction of the injector 50 than the straight part 15.

[0020] The bent portion 13 is provided near the base end of the injector 50. The bent portion 13 bends the exhaust pipe 10 so that the inclination of a straight portion 17 downstream of the bent portion 13 is greater than the inclination of the straight portion 16. The straight portion 17 downstream of the bent portion 13 extends downward toward the attachment position of the injector 50. The bent portion 14 bends the exhaust pipe immediately downstream of the bent portion 13 so that the straight portion 18 downstream of the injector 50 extends along the axial direction of the injector 50. The straight portion 18 downstream of the injector 50 extends at a slight upward inclination with respect to the horizontal plane.

[0021] These bent portions 12, 13, and 14 allow the piping path of the exhaust pipe 10 to avoid interference with, for example, the lower structure of the vehicle (such as a cross member of the suspension). Also, by using an injector 50 attached so as to inject the reducing agent toward the rear of the vehicle, the reducing agent can be injected downstream inside the exhaust pipe 10.

[0022] The exhaust pipe 10 has a protruding region 19 that protrudes due to bending of the bent portion 14. That is, in the exhaust pipe 10, a certain range downstream of the bent portion 14 is the protruding region 19 formed by bending the bent portion 14. As an example, the protruding region 19 is a region that includes a point located vertically lowest (a point with the smallest height above ground) in the exhaust passage including the exhaust pipe 10. In the protruding region 19, a dispersion plate (not shown) is disposed inside the exhaust pipe 10. The dispersion plate is disposed, for example, inside the exhaust pipe 10 so as to face the injector. The dispersion plate has a function of stirring the exhaust gas passing through the exhaust pipe 10 and suppressing variations in the exhaust oxygen concentration inside the exhaust pipe 10.

[0023] FIG. 2 is a partially enlarged perspective view of the exhaust pipe heat insulation structure 1 shown in FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. As shown in FIGS. 2 and 3, the first heat insulator 20 has a pair of heat shield plates 21, 22 provided along the outer surface of the exhaust pipe 10 upstream of the protruding region 19. The second heat insulator 30 has a pair of heat shield plates 31, 32 provided along the outer surface of the exhaust pipe 10 downstream of the protruding region 19. The first heat insulator 20 has a left-right split structure with the heat shield plates 21, 22 when viewed from the axial direction of the exhaust pipe 10. Similarly, the second heat insulator 30 has a left-right split structure with the heat shield plates 31, 32 when viewed from the axial direction of the exhaust pipe 10.

[0024] The heat shield 21 is disposed on one side in the horizontal direction of the first heat insulator 20. The heat shield 22 is disposed on the other side in the horizontal direction of the first heat insulator 20. The heat shield 31 is disposed on one side in the horizontal direction of the second heat insulator 30. The heat shield 32 is disposed on the other side in the horizontal direction of the second heat insulator 30. The heat shields 21, 22, 31, and 32 are formed, for example, by pressing or the like, and each has a substantially semicircular cross section. The heat shields 21, 22, 31, and 32 can be made of, for example, stainless steel or the like.

[0025] Each of the pair of heat shield plates 21, 22 constituting the first heat insulator 20 includes arc portions 21a, 22a, lower end portions 21b, 22b, and upper end portions 21c, 22c. The overlapping portions of the lower end portions 21b, 22b are joined together, and the overlapping portions of the upper end portions 21c, 22c are joined together, so that the first heat insulator 20 is formed into a cylindrical shape. The lower end portions 21b, 22b and the upper end portions 21c, 22c are joined together by spot welding or the like, for example, at joining positions that take into consideration vibration suppression of the entire first heat insulator 20.

[0026] Each of the pair of heat shield plates 31, 32 constituting the second heat insulator 30 includes arc portions 31a, 32a, lower end portions 31b, 32b, and upper end portions 31c, 32c. The second heat insulator 30 is formed into a cylindrical shape by joining the overlapping portions of the lower end portions 31b, 32b and the upper end portions 31c, 32c together. The lower end portions 31b, 32b and the upper end portions 31c, 32c are joined by spot welding or the like at joining positions that take into consideration the overall vibration suppression of the second heat insulator 30.

[0027] The downstream end 20a of the first heat insulator 20 and the upstream end 30a of the second heat insulator 30 have an overlapping portion R so as to form gaps S3, S4 that are aligned in the circumferential direction of the exhaust pipe 10 and communicate with the outside. In this embodiment, the upstream end 30a of the second heat insulator 30 has an expanded diameter at the overlapping portion R and is disposed so as to be on the outer side in the radial direction of the exhaust pipe 10 relative to the downstream end 20a of the first heat insulator 20.

[0028] As shown in FIG. 3, in the overlapping portion R, the pair of heat shield plates 21, 22 are provided with step portions 23, 24 that bulge outward in the radial direction. The step portion 23 of the heat shield plate 21 is formed by one bent portion provided between the arc portion 21a and the lower end portion 21b, and one bent portion provided between the arc portion 21a and the upper end portion 21c. The step portion 24 of the heat shield plate 22 is formed by one bent portion provided between the arc portion 22a and the lower end portion 22b, and one bent portion provided between the arc portion 22a and the upper end portion 22c. As a result, between the first heat insulator 20 and the exhaust pipe 10, a gap portion S1 located between the step portions 23, 24 on the lower end portions 21b, 22b side and the exhaust pipe 10, and a gap portion S2 located between the step portions 23, 24 on the upper end portions 21c, 22c side and the exhaust pipe 10 are formed.

[0029] 3, in the overlapping portion R, the pair of heat shield plates 31, 32 are provided with stepped portions 33, 34 that bulge outward in the radial direction. The stepped portion 33 of the heat shield plate 31 is composed of two bent portions provided between the arc portion 31a and the lower end portion 31b, and two bent portions provided between the arc portion 31a and the upper end portion 31c. The stepped portion 34 of the heat shield plate 32 is composed of two bent portions provided between the arc portion 32a and the lower end portion 32b, and two bent portions provided between the arc portion 32a and the upper end portion 32c. As a result, between the first heat insulator 20 and the second heat insulator 30, a gap portion S3 is formed between the step portions 23, 24 on the lower end portions 21b, 22b side and the step portions 33, 34 on the lower end portions 31b, 32b side, and a gap portion S4 is formed between the step portions 23, 24 on the upper end portions 21c, 22c side and the step portions 33, 34 on the upper end portions 31c, 32c side.

[0030] 3 and 4, a wire mesh 40 is disposed in the gap at least in the portion on the extension direction side (here, the vertically downward side) of the extension region 19. The wire mesh 40 is formed of, for example, stainless steel. The wire mesh 40 allows liquids such as water to pass through while capturing foreign matter such as dead grass.

[0031] In this embodiment, the wire mesh 40 is disposed around the entire circumferential direction of the exhaust pipe 10, including the gap portions S3 and S4. The wire mesh 40 is disposed with a substantially constant thickness in the gap portions S3 and S4. The wire mesh 40 is disposed in a compressed state between the arc portions 21a and 22a of the heat shield plates 21 and 22 of the first heat insulator 20 and the arc portions 31a and 32a of the heat shield plates 31 and 32 of the second heat insulator 30.

[0032] When arranging the wire mesh all around the exhaust pipe 10 in the circumferential direction, including the gap portions S3 and S4, the wire mesh 40 can be joined in advance by spot welding to one of the downstream end 20a of the first heat insulator 20 and the upstream end 30a of the second heat insulator 30. In this state, the pair of heat shields 31 and 32 are arranged so as to cover the downstream end 20a of the first heat insulator 20, and the lower ends 31b and 32b and the upper ends 31c and 32c are joined by spot welding or the like, whereby the wire mesh 40 can be easily arranged all around the exhaust pipe 10 in the circumferential direction, including the gap portions S3 and S4.

[0033] Next, the above-mentioned bracket 60 and base portion 70 will be described in detail. Fig. 4 is a perspective view showing the heat insulating structure of the exhaust pipe shown in Fig. 1 with the heat insulator removed. Fig. 5 is an enlarged cross-sectional view of a main part of the heat insulating structure of the exhaust pipe shown in Fig. 1.

[0034] As shown in Figures 4 and 5, the exhaust pipe insulation structure 1 is provided with a bracket 60 and a base portion 70 used for mounting the exhaust pipe 10 to a vehicle. In arranging the bracket 60 and the base portion 70, in this embodiment, an opening 35 (see Figures 1 and 5) is provided to expose the exhaust pipe 10 from a part of the second heat insulator 30. The opening 35 has, for example, a rectangular shape with rounded corners in a plan view, and is provided along the circumferential surface of the second heat insulator 30. In this embodiment, the opening 35 and the base portion 70 are provided at a position that is above the exhaust pipe 10 when the exhaust pipe 10 is mounted to the vehicle.

[0035] The bracket 60 is made of, for example, stainless steel. The bracket 60 has a base end 61 fixed to the base portion 70, a rising portion 62 rising from one edge of the base end 61, and a tip end 63 bent from the tip of the rising portion 62, and is generally C-shaped in side view. The tip end 63 extends longer than the other edge of the base end 61. The tip end 63 is provided with an insertion hole 64 through which the stud bolt B is inserted.

[0036] 5, a rubber member D that serves as a suspension point for the exhaust pipe 10 relative to the vehicle is attached to the tip portion 63. The rubber member D is fixed in advance to, for example, a frame F on the vehicle side, and is provided with bolt holes corresponding to the stud bolts B. The exhaust pipe 10 can be attached to the vehicle by screwing the stud bolts B, which are inserted through insertion holes 64 in the tip portion 63, into the bolt holes in the rubber member D.

[0037] The base 70 is formed of stainless steel, for example, like the pair of heat shield plates 31, 32 constituting the second heat insulator 30. As shown in Figs. 4 and 5, the base 70 has a box-shaped main body 71 with one side open, and a flange 72 provided around the entire periphery of the edge of the open side of the main body 71. The top surface 71a of the main body 71 is, for example, an inclined surface such that the distance from the exhaust pipe 10 decreases toward the downstream side of the exhaust pipe 10. The base end 61 of the bracket 60 is fixed to the top surface 71a of the main body 71 by, for example, welding. There is no particular limit to the height of the main body 71 from the exhaust pipe 10, but in this embodiment, the height is such that the entire top surface 71a is located outside the opening 35.

[0038] The flange portion 72 has a curved shape that follows the circumferential surface of the exhaust pipe 10. The flange portion 72 is fixed without any gaps to the circumferential surface of the exhaust pipe 10 exposed from the opening 35, for example by welding. By fixing the flange portion, an internal space V that is sealed by the exhaust pipe 10 and the main body portion 71 is formed between the exhaust pipe 10 and the bracket 60, as shown in FIG. 5 . The internal space V is filled with air. The air in the internal space V functions as a heat insulating layer 80 between the exhaust pipe 10 and the bracket 60.

[0039] By forming the opening 35, a gap portion S5 is formed between the exhaust pipe 10 and the second heat insulator 30. A wire mesh 90 is arranged in this gap portion S5 as shown in Fig. 5. The wire mesh 90 is made of, for example, stainless steel. Like the wire mesh 40 (see Fig. 3) arranged around the entire circumferential direction of the exhaust pipe 10 including the above-mentioned gap portions S3 and S4, the wire mesh 90 allows liquids such as water to pass through while capturing foreign matter such as dead grass.

[0040] The wire mesh 90 is disposed in the gap portion S5 between the exhaust pipe 10 and the second heat insulator 30, around the entire periphery of the edge of the opening 35. In this embodiment, the flange portion 72 of the base portion 70 extends to the gap portion S5, and the wire mesh 90 is disposed around the base portion 70 so as to fill the gap between the second heat insulator 30 and the flange portion 72.

[0041] As described above, in this exhaust pipe insulation structure 1, the base portion 70 of the bracket 60 forms the insulation layer 80 between the exhaust pipe 10 and the bracket 60. This makes it possible for the insulation layer 80 to block heat to the bracket 60 even if the exhaust pipe 10 itself becomes hot due to high-temperature exhaust gas. This makes it possible to prevent heat damage to the rubber member D, which serves as the suspension point of the exhaust pipe 10, from occurring.

[0042] In the exhaust pipe insulation structure 1, the exhaust pipe 10 has a protruding region 19 that protrudes due to bending or swelling of the exhaust pipe 10. The heat insulator is composed of a first heat insulator 20 that covers the exhaust pipe 10 upstream of the protruding region 19, and a second heat insulator 30 that covers the exhaust pipe downstream of the protruding region 19. The base portion 70 is disposed in an opening 35 provided in the second heat insulator 30. With this configuration, it is possible to support the exhaust pipe 10 in a well-balanced manner via the bracket 60.

[0043] In the exhaust pipe insulation structure 1, the insulation layer 80 is sealed by the exhaust pipe 10 and the base 70. This makes it possible to prevent foreign matter from entering the insulation layer 80 and coming into contact with high-temperature parts such as the exhaust pipe 10.

[0044] In the exhaust pipe insulation structure 1, the opening 35 and the base portion 70 are provided in a position that is above the exhaust pipe 10 when the exhaust pipe 10 is attached to a vehicle. This configuration improves the accessibility of the bracket 60 to the rubber member D that serves as the suspension point of the exhaust pipe 10. Also, compared to a case in which the opening 35 and the base portion 70 are provided in a position below the exhaust pipe 10, the areas around the opening 35 and the base portion 70 can be prevented from being exposed to foreign matter such as dead grass.

[0045] In the exhaust pipe thermal insulation structure 1, a wire mesh 90 is disposed in a gap portion S5 between the exhaust pipe 10 and the second heat insulator 30 at the opening 35. This makes it possible to prevent foreign matter such as dead grass from entering the inside of the second heat insulator 30 from the outside.

[0046] The present disclosure is not limited to the above embodiment. For example, in the above embodiment, the upstream end 30a of the second heat insulator 30 is disposed radially outward of the exhaust pipe 10 relative to the downstream end 20a of the first heat insulator 20, but this arrangement may be reversed. That is, the downstream end 20a of the first heat insulator 20 may be disposed radially outward of the exhaust pipe 10 relative to the upstream end 30a of the second heat insulator 30. In addition, in the above embodiment, the base portion 70 is disposed in the opening 35 provided in the second heat insulator 30, but the base portion 70 may be disposed in the opening 35 provided in the first heat insulator 20.

[0047] In the above embodiment, the opening 35 and the base 70 are provided at a position that is on the upper side of the exhaust pipe 10 when the exhaust pipe 10 is attached to the vehicle, but this is not limited to this. The opening 35 and the base 70 may be provided at a position that is on the left or right side or on the lower side of the exhaust pipe 10 when the exhaust pipe 10 is attached to the vehicle.

[0048] The insulating layer 80 does not necessarily have to be sealed by the exhaust pipe 10 and the base 70. For example, the base 70 may be frame-shaped instead of box-shaped. Even in this case, the insulating layer 80 of air is formed between the exhaust pipe 10 and the bracket 60, so the above-mentioned effects can be achieved. Even when the base 70 is frame-shaped, it is preferable to provide a wall surface that separates the insulating layer 80 on the surface facing the axial direction of the exhaust pipe 10. This makes it possible to prevent foreign matter such as dead grass from entering the insulating layer 80. [Explanation of symbols]

[0049] 1...insulating structure of exhaust pipe, 10...exhaust pipe, 19...projection area, 20...first heat insulator, 30...second heat insulator, 35...opening, 60...bracket, 70...base portion, 80...insulating layer, 90...wire mesh, D...rubber member, S5...gap portion.

Claims

1. A thermal insulation structure for an exhaust pipe connected to an internal combustion engine of a vehicle, Exhaust pipe and a heat insulator covering the exhaust pipe; a bracket to which a rubber member is attached, the rubber member being a suspension point for the exhaust pipe relative to the vehicle; the heat insulator has an opening through which the exhaust pipe is exposed, a base portion of the bracket is provided at the opening portion so that a heat insulating layer is formed between the exhaust pipe and the bracket, The rubber member is fixed to a frame of the vehicle, A thermal insulation structure for an exhaust pipe, wherein at least a part of a frame of the vehicle is positioned in a space between the opening and the rubber member so as to shield the rubber member when viewed from the opening.

2. The exhaust pipe has a protruding region that protrudes due to bending or bulging of the exhaust pipe, The heat insulator comprises: a first heat insulator covering the exhaust pipe upstream of the protruding area; a second heat insulator covering the exhaust pipe downstream of the protruding area, The heat insulating structure for an exhaust pipe according to claim 1 , wherein the base portion is disposed in the opening portion formed in the second heat insulator.

3. 3. The heat insulating structure for an exhaust pipe according to claim 1, wherein the heat insulating layer is sealed by the exhaust pipe and the base.

4. 4. The exhaust pipe insulation structure according to claim 1, wherein the opening and the base are provided at positions that are above the exhaust pipe when the exhaust pipe is attached to the vehicle.

5. 5. The heat insulating structure for an exhaust pipe according to claim 1, wherein a wire mesh is disposed in a gap between the exhaust pipe and the heat insulator at the opening.

6. An insulating structure for an exhaust pipe described in any one of claims 1 to 5, wherein the opening and the rubber member are spaced apart in the axial direction of the exhaust pipe.

7. The rubber member is spaced from the opening downstream of the exhaust pipe, 7. The heat insulating structure for an exhaust pipe according to claim 6, wherein the top surface of the base portion is an inclined surface such that the distance from the exhaust pipe becomes gradually smaller toward the downstream side of the exhaust pipe.

Images