insulator

Abstract

To provide an insulator which can properly cover even an exhaust pipe around a protruding member for attaching an addition valve or the like, and can properly drain intruded rain water or the like by suppressing an increase of a manufacturing step and the number of part items.SOLUTION: A protruding member 34 protruding outward from an exhaust pipe and having a flange part at a tip is arranged at a bent part of an exhaust pipe 30, an insulator 2 covers at least the bent part, and a first halved insulator 10 and a second halved insulator 20 are combined to each other, and exert a cylindrical shape. At least a part of a first one-edge part 11 and at least a part of a second one-edge part 21 are joined to each other, a part of a first other edge part 12 and a part of a second other edge part 22 are joined to each, and the first one-edge part and the second one-edge part are located at an upper side in a vertical direction rather than the first other edge part and the second other edge part, a clearance between the first other edge part and the second other edge part is set as a drainage clearance, and notched parts 13, 23 for avoiding an interference with the protruding member are formed at least at either of the first other edge part and the second other edge part.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an insulator that covers and insulates a portion of an exhaust pipe in an exhaust path of an internal combustion engine. [Background technology]

[0002] The exhaust pipe of a vehicle equipped with an internal combustion engine becomes extremely hot due to exhaust gases. The hot exhaust pipe is located under the floor, away from the vehicle occupants. Therefore, when the vehicle is driven on an unpaved road with dry grass or the like, the exposed exhaust pipe becomes hot and is exposed under the floor, and there is a possibility that the dry grass or the like may come into contact with the exposed exhaust pipe and ignite. Therefore, there is a need for an insulator that can cover and insulate the exhaust pipe in areas where the dry grass or the like may ignite.

[0003] For example, Patent Document 1 discloses an exhaust pipe structure that is equipped with a heat protector (equivalent to an insulator) that covers part of the exhaust pipe by combining an upper half insulator and a lower half insulator that are divided into upper and lower halves into a cylindrical shape. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-144719 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, in vehicles equipped with a diesel engine as an internal combustion engine, an additive valve that injects a reaction liquid (fuel, urea water, etc.) used in an exhaust purification device (oxidation catalyst, SCR catalyst, etc.) may be attached to the exhaust pipe. If the additive valve is attached to a part of the exhaust pipe where the above-mentioned dried grass, etc. may ignite, it is desirable to also cover the exhaust pipe around the additive valve with an insulator.

[0006] 12 shows an example of the appearance of an exhaust pipe 130 and an example of an exploded perspective view of an upper half insulator 110 and a lower half insulator 120 that are divided into upper and lower halves as in the conventional Patent Document 1. Also, Fig. 13 shows an example of a conventional insulator in which the upper half insulator 110 and the lower half insulator 120 shown in Fig. 12 are combined to form a cylindrical insulator 102 that covers the periphery of the exhaust pipe 130.

[0007] As shown in the example of FIG. 12 , when a portion of the exhaust pipe 130 is bent downward and a protruding member 134 for attaching an additive valve 180 or the like is provided at the bent portion, if a cylindrical insulator 102 (see FIG. 13 ) is formed by combining an upper half insulator 110 and a lower half insulator 120, which are divided into upper and lower halves as in Patent Document 1, the protruding member 134 becomes an obstacle. In this case, the lower half insulator 120 can only cover the exhaust pipe 130 from the upstream side to just before the protruding member 134, and cannot adequately cover the area B around the protruding member 134 and downstream of the protruding member 134 (see FIG. 13 ). If dead grass or the like comes into contact with area B, it may ignite, which is undesirable.

[0008] 13, if rainwater or the like seeps in between the exhaust pipe 130 and the insulator 102, the exhaust pipe 130 may corrode or crack due to heat shock. For this reason, as shown in Figures 12 and 13, it is necessary to provide a drainage hole 128 at an appropriate location below the lower half insulator 120. If the drainage hole 128 is provided, it is necessary to block the drainage hole 128 with a wire mesh or the like (not shown) that does not impede drainage from the drainage hole 128 and prevents dead grass or the like from entering through the drainage hole 128 and coming into contact with the exhaust pipe 130.

[0009] The heat protector (corresponding to an insulator) described in Patent Document 1 is a type that is divided into upper and lower parts, and therefore, as described above, when a protruding member for attaching an additive valve or the like is provided in the exhaust pipe, it is not possible to adequately cover the periphery of the protruding member. Furthermore, since the heat protector has openings on the sides but no openings on the bottom, rainwater or the like cannot be adequately drained if it gets in. Adding drainage holes or a wire mesh or the like below the heat protector to adequately drain rainwater or the like is undesirable because it increases the manufacturing process and the number of parts.

[0010] The present invention was devised in consideration of these points, and aims to provide a cylindrical insulator that covers part of the exhaust pipe in the exhaust path, that can also properly cover the exhaust pipe around a protruding member for attaching an additive valve or the like, and that can properly drain rainwater or the like that has infiltrated therein while suppressing an increase in the manufacturing process and the number of parts. [Means for solving the problem]

[0011] In order to solve the above problems, a first invention is a cylindrical insulator that covers a portion of an exhaust pipe in an exhaust path of an internal combustion engine. The exhaust pipe covered by the insulator has a bent portion, and the bent portion is provided with a protruding member that protrudes outward from the exhaust pipe and has a flange portion at its tip for attaching a device. The insulator is fixed to the exhaust pipe and covers at least the bent portion, and is formed into a cylindrical shape by combining a first half insulator and a second half insulator, each of which has an arc-shaped cross section perpendicular to the longitudinal direction of the exhaust pipe. The first half insulator has two edges along the longitudinal direction, namely, a first one-side edge and a first other-side edge. The second half insulator has two edges along the longitudinal direction, namely, a second one-side edge and a second other-side edge. The insulator is assembled into a cylindrical shape by joining at least a portion of the first one-side edge portion and the second one-side edge portion and joining a portion of the first other-side edge portion and the second other-side edge portion, and the first one-side edge portion and the second other-side edge portion are positioned vertically above the first other-side edge portion and the second other-side edge portion. The insulator forms a drainage gap between the first other-side edge portion and the second other-side edge portion, which is a gap that communicates between a heat-shielding space that is a space surrounded by the outer peripheral surface of the exhaust pipe and the inner peripheral surface of the insulator and a space outside the insulator. At least one of the first other-side edge portion and the second other-side edge portion is provided with a notch that avoids interference with the protruding member.

[0012] Next, a second invention is the insulator according to the first invention, wherein the first other edge portion and the second other edge portion form the drainage gap while overlapping in a circumferential direction when viewed in a virtual cross section perpendicular to the longitudinal direction of the exhaust pipe, and a path from the outer space through the drainage gap to the heat-shielding space is bent when viewed in the virtual cross section.

[0013] Next, a third invention is the insulator according to the first or second invention, wherein the heat-shielding space is filled with a heat insulating material, and at least the vicinity of the first other edge and the vicinity of the second other edge in the heat-shielding space are hollow portions that are not filled with the heat insulating material.

[0014] Next, a fourth invention is an insulator according to the first or second invention, wherein the portions of the first other edge portion and the second other edge portion that are located vertically below the protruding member form the drainage gap without being joined to each other.

[0015] Next, a fifth invention is an insulator according to the first or second invention, wherein the device attached to the flange portion is an addition valve that injects a reaction liquid used in an exhaust purification device connected to the exhaust pipe into the exhaust pipe. [Effects of the Invention]

[0016] According to the first aspect of the present invention, the first and second half insulators are not vertically divided but are so-called left-right divided (the first one-side edge portion and the second one-side edge portion are positioned vertically above the first and second other-side edge portions). Cutouts are provided in the first and second other-side edge portions, which are boundaries between the first and second half insulators, to prevent interference with the protruding member. This allows the exhaust pipe around the protruding member to be appropriately covered by the insulators without providing holes in the first and second half insulators to prevent interference with the protruding member. Furthermore, the first and second other-side edge portions, which face each other when assembled into a cylindrical shape, are positioned vertically below the first and second one-side edge portions, and at least a portion of the first and second other-side edge portions are not joined to each other, forming a relatively narrow drainage gap. This eliminates the need to provide drainage holes in the first and second half insulators. Furthermore, if the drainage gaps are designed to be difficult for dead grass to get into (relatively narrow gaps or labyrinth-shaped gaps, etc.), there is no need to block the gaps with wire mesh, etc. Therefore, it is possible to properly drain infiltrating rainwater, etc., while suppressing an increase in the manufacturing process and number of parts.

[0017] According to the second invention, the path from the outside space through the drainage gap to the heat-shielding space is curved, making it difficult for dead grass and other debris to get in through the drainage gap. This eliminates the need to block the drainage gap with wire mesh, etc. This allows for proper drainage of infiltrating rainwater and other debris while minimizing the need for additional manufacturing processes and parts.

[0018] According to the third aspect of the present invention, by filling the heat-shielding space with a heat insulating material, it is possible to more effectively block the heat transferred from the exhaust pipe to the insulator. Also, if rainwater or the like seeps into the heat-shielding space, the infiltrating rainwater or the like is easily drained through the drainage gap because the area around the drainage gap is hollow and no heat insulating material is placed around it.

[0019] According to the fourth invention, a drainage gap can be reliably provided in the portion of the first other edge portion and the second other edge portion of the insulator that is a combination of a first half insulator and a second half insulator that is located vertically below the protruding member, and the drainage gap can be secured to be as long as possible.

[0020] According to the fifth invention, when the device attached to the flange portion of the protruding member protruding outward from the exhaust pipe is an additive valve, the insulator can properly cover the exhaust pipe around the protruding member, and can properly drain rainwater and the like that has infiltrated while suppressing an increase in the manufacturing process and the number of parts. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a diagram illustrating an example of an exhaust path in a vehicle equipped with an internal combustion engine. [Figure 2] 1 is a diagram illustrating an example of the external appearance (left side view) of an exhaust pipe unit having an insulator of the present invention and an exhaust pipe covered with the insulator. FIG. [Figure 3] FIG. 3 is a cross-sectional view of a portion of FIG. 2. [Figure 4] FIG. 3 is a perspective view of the exhaust pipe unit shown in FIG. 2. [Figure 5] 5 is an exploded perspective view illustrating an example of the appearance of an exhaust pipe, a first half insulator, a second half insulator, and the like that constitute the exhaust pipe unit shown in FIG. 4. FIG. [Figure 6] FIG. 3 is a top view of the exhaust pipe unit shown in FIG. 2. [Figure 7] FIG. 3 is a bottom view of the exhaust pipe unit shown in FIG. 2. [Figure 8] This is a cross section taken along line VIII-VIII in Figure 2. [Figure 9] FIG. 5 is a view of the periphery of the protruding member shown in FIG. 4 as seen from direction IX, illustrating an example in which the first other edge portion and the second other edge portion pass through the protruding member and in which notches are provided in both the first other edge portion and the second other edge portion. [Figure 10]FIG. 5 is a view of the periphery of the protruding member shown in FIG. 4 as seen from the X direction, illustrating an example in which the first other-side edge portion and the second other-side edge portion pass near the protruding member, and in which a notch is provided in the first other-side edge portion and no notch is provided in the second other-side edge portion. [Figure 11] This is a cross section taken along line XI-XI in FIG. [Figure 12] FIG. 10 is an exploded perspective view illustrating an example of the appearance of a conventional upper half insulator and a lower half insulator of a vertically divided type, and an exhaust pipe provided with a protruding member. [Figure 13] FIG. 13 is a diagram illustrating an example of the appearance of a conventional exhaust pipe unit in which the conventional upper half insulator and the lower half insulator shown in FIG. 12 are combined to form a cylindrical shape that covers the exhaust pipe. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, an embodiment of the insulator 2 of the present invention will be described with reference to the drawings. In the description of this embodiment, an insulator 2 that covers an exhaust pipe around a urea water addition valve 80b (corresponding to an addition valve) that adds (injects) urea water into the exhaust pipe to purify exhaust gas from an internal combustion engine 71 mounted on a vehicle 70 shown in the example of Fig. 1 will be described as an example. Note that when front, rear, left, right, up, and down are written in the drawings, the up and down directions indicate directions going up and down in the vertical direction, the front and rear direction indicates the front-to-rear direction of the vehicle 70, and the left and right direction indicates the left and right direction of the vehicle 70.

[0023] [Exhaust path 75 of a vehicle 70 equipped with an internal combustion engine 71 (Fig. 1)] As shown in Fig. 1, an internal combustion engine 71 is mounted on the front of a vehicle 70. In this example, the internal combustion engine 71 is a diesel engine. The internal combustion engine 71 takes in intake air via a compressor of a supercharger 73 and an intake manifold 72 and uses the intake air for combustion. Exhaust gas generated by combustion in the internal combustion engine 71 is guided to an exhaust path 75.

[0024] The exhaust path 75 is formed by connecting an exhaust manifold 74, a turbine of the turbocharger 73, a first purification device 76, a NOx aftertreatment device 77, a second purification device 78, a silencer 79, etc. directly or via an exhaust pipe. The first purification device 76 has an oxidation catalyst that purifies CO (carbon monoxide) and HC (hydrocarbons) and a particulate collection filter that collects particulates such as soot. The NOx aftertreatment device 77 has an SCR catalyst that purifies NOx using urea water (corresponding to the reaction liquid) injected from a urea water addition valve 80b (corresponding to the addition valve). The second purification device 78 has an oxidation catalyst that purifies ammonia based on the urea water injected from the urea water addition valve 80b but remaining in excess.

[0025] A fuel addition valve 80a (corresponding to an addition valve) that injects fuel (corresponding to a reaction liquid) is provided in the exhaust pipe upstream of the first purification device 76, and a urea water addition valve 80b (corresponding to an addition valve) that injects urea water (corresponding to a reaction liquid) is provided in the exhaust pipe upstream of the NOx post-treatment device 77. The fuel addition valve 80a is controlled by a control device (not shown), and when the amount of soot and the like trapped by the particulate collection filter of the first purification device 76 reaches a predetermined amount or more, the fuel addition valve 80a injects fuel into the exhaust pipe to combust and incinerate the trapped soot and the like. The urea water addition valve 80b is controlled by the control device (not shown), and injects urea water into the exhaust pipe to purify NOx by a reduction reaction in the NOx post-treatment device 77.

[0026] As shown in the example of Figure 1, the exhaust path 75, which becomes hot due to the exhaust gas from the internal combustion engine 71, is positioned to avoid occupants and is mostly exposed under the floor of the vehicle 70. Therefore, when the vehicle 70 is traveling on an unpaved road, there is a possibility that dry grass 90 may come into contact with part of the exhaust path 75 and ignite. In particular, the exhaust path upstream of the NOx aftertreatment device 77 is close to the internal combustion engine 71 and may receive fuel from the fuel addition valve 80a, so it is likely to become hot. For this reason, in Figure 1, the exhaust pipe 30 between the first purification device 76 and the NOx aftertreatment device 77 needs to be covered with an appropriate insulator.

[0027] In the description of this embodiment, the insulator 2 covering the exhaust pipe 30 of the exhaust pipe unit 1 between the first purification device 76 and the NOx aftertreatment device 77 will be taken as an example. The insulator 2 will be described in detail below.

[0028] ●[Appearance and structure of the exhaust pipe unit 1 having the exhaust pipe 30, the insulator 2, etc. (Figures 2 to 7)] Fig. 2 is an example of a left side view of the exhaust pipe unit 1 shown in Fig. 1, and Fig. 3 is a cross-sectional view of a portion of Fig. 2. The exhaust pipe unit 1 has an exhaust pipe 30, an insulator 2, a downstream insulator 3, etc. The exhaust pipe 30 has an upstream exhaust pipe 31, a downstream exhaust pipe 32, and a distributor 33 connecting the upstream exhaust pipe 31 and the downstream exhaust pipe 32. The upstream sides of the upstream exhaust pipe 31 and the distributor 33 are covered by the cylindrical insulator 2, and the downstream sides of the downstream exhaust pipe 32 and the distributor 33 are covered by the cylindrical downstream insulator 3.

[0029] The dispersion device 33 has a plurality of collision plates against which the urea water injected from the urea water addition valve 80b attached to the protruding member 34 collides, atomizing the urea water that collides and dispersing it within the exhaust pipe 30. An upstream end flange 31a is provided at the upstream end of the exhaust pipe 30, which is connected to a flange at the downstream end of the first purification device 76 (see FIG. 1). A downstream end flange 32a is provided at the downstream end of the exhaust pipe 30, which is connected to a flange at the upstream end of the NOx aftertreatment device 77 (see FIG. 1).

[0030] 2, the upstream exhaust pipe 31 extends toward the underfloor while avoiding surrounding components (not shown) inside the vehicle 70, not shown, and has one or more bent portions, and some of the bent portions are provided with a protruding member 34 that protrudes outward from the upstream exhaust pipe 31 and has a flange portion (protruding portion flange 34b (see FIGS. 3 and 4)) at the tip of which a device (such as an addition valve) is attached. In this example, the device attached to the flange portion (protruding portion flange 34b) is a urea water addition valve 80b (corresponding to an addition valve) that injects urea water (corresponding to a reaction liquid) into the exhaust pipe 30 to be used in a NOx aftertreatment device 77 (corresponding to an exhaust purification device) connected to the exhaust pipe 30 (exhaust pipe unit 1).

[0031] 3, the protruding member 34 has a socket 34a through which the urea water addition valve 80b is inserted, communicating the inside and outside of the exhaust pipe 30, and a protruding portion flange 34b (corresponding to a flange portion) for attaching the urea water addition valve 80b. The protruding member-attached bent portion 30a, which is the bent portion where the protruding member 34 is provided, is bent so that the upstream side of the exhaust gas faces upward and the downstream side of the exhaust gas faces downward.

[0032] The insulator 2 is fixed to the upstream exhaust pipe 31. For example, in the vicinity of the upstream end flange 31a in Fig. 2, the inner peripheral surface of the insulator 2 has a connection portion, which is welded or the like, to the outer peripheral surface of the upstream exhaust pipe 31. Downstream of the connection portion, as shown in Fig. 8, the inner peripheral surface of the insulator 2 and the outer peripheral surface of the upstream exhaust pipe 31 are not in contact with each other, and a heat-shielding space 31k is formed. In the example of Fig. 8, the heat-shielding space 31k is filled with a heat insulating material 36 except for some hollow portions.

[0033] As shown in FIG. 2, the cylindrical insulator 2 covers the entire upstream exhaust pipe 31, covering at least the bent portion 30a with a protruding member (corresponding to the bent portion). As shown in FIG. 5, the insulator 2 is composed of a first half insulator 10 having an arc-shaped cross section 10m perpendicular to the longitudinal direction of the exhaust pipe 30, and a second half insulator 20 having an arc-shaped cross section 20m perpendicular to the longitudinal direction of the exhaust pipe 30. As shown in FIG. 4, the first half insulator 10 and the second half insulator 20 are combined to form the cylindrical insulator 2. Similarly, the cylindrical downstream insulator 3 covers the entire downstream exhaust pipe 32. As shown in FIG. 5, the downstream insulator 3 is composed of a first downstream half insulator 40 and a second downstream half insulator 50. As shown in FIG. 4, the first downstream half insulator 40 and the second downstream half insulator 40 are combined to form the downstream insulator 3 having a cylindrical shape.

[0034] 5, the first half insulator 10 has a first one-side edge portion 11 and a first other-side edge portion 12, which are two edges extending along the longitudinal direction of the exhaust pipe 30. The second half insulator 20 has a second one-side edge portion 21 and a second other-side edge portion 22, which are two edges extending along the longitudinal direction of the exhaust pipe 30. Similarly, the first downstream half insulator 40 has a first downstream one-side edge portion 41 and a first downstream other-side edge portion 42. The second downstream half insulator 50 has a second downstream one-side edge portion 51 and a second downstream other-side edge portion 52.

[0035] The first one-side edge portion 11 and the second one-side edge portion 21 (see FIG. 5), which face each other when the first half insulator 10 and the second half insulator 20 are combined into a cylindrical shape, are preferably set so as to pass above each of the imaginary cross sections 30m, 30n, and 30p (see FIG. 4; imaginary cross sections that are not horizontal) perpendicular to the longitudinal direction of the exhaust pipe 30 covered by the insulator 2. In the insulator 2, the first one-side edge portion 11 and the second one-side edge portion 21 are joined to each other at the joint 2s, for example, in FIG. 6 when viewed from above. In other words, at least a portion of the first one-side edge portion 11 and the second one-side edge portion 21 are joined to each other.

[0036] The first other-side edge portion 12 and the second other-side edge portion 22 (see FIG. 5), which face each other when the first half insulator 10 and the second half insulator 20 are assembled into a cylindrical shape, are preferably set so as to pass near the bottom ends of each of the imaginary cross sections 30m, 30n, and 30p (see FIG. 4; imaginary cross sections that are not horizontal) perpendicular to the longitudinal direction of the exhaust pipe 30 covered by the insulator 2. In the insulator 2 shown in FIG. 7, for example, as viewed from below, the first other-side edge portion 12 and the second other-side edge portion 22 are joined to each other at the joint 2s, and are not joined to each other at other locations. In other words, portions of the first other-side edge portion 12 and the second other-side edge portion 22 are joined to each other. The first one-side edge portion 11 and the second one-side edge portion 21 are located vertically above the first other-side edge portion 12 and the second other-side edge portion 22. As shown in FIG. 7, the protruding member 34 is provided at a position that is visible when the exhaust pipe unit 1 (exhaust pipe 30) is viewed from below.

[0037] ●[Drainage gap 12s structure (Figure 8)] Fig. 8 shows a cross section taken along line VIII-VIII in Fig. 2, which is the virtual cross section 30n shown in Fig. 4. As shown in Fig. 8, an inner pipe 31u (see Fig. 3) is arranged inside the upstream exhaust pipe 31, and a heat insulating space 31v surrounded by the outer circumferential surface of the inner pipe 31u and the inner circumferential surface of the upstream exhaust pipe 31 is a hollow portion. In addition, the outer circumferential surface of the inner pipe 31u and the inner circumferential surface of the upstream exhaust pipe 31 are connected by welding or the like near the upstream end flange 31a.

[0038] The insulator 2 is disposed outside the upstream exhaust pipe 31 and covers the upstream exhaust pipe 31. A heat-shielding space 31k is formed between the outer circumferential surface of the upstream exhaust pipe 31 and the inner circumferential surface of the insulator 2. The heat-shielding space 31k is filled with a heat insulating material 36 such as glass wool, but a portion of the heat-shielding space 31k is left empty without being filled with the heat insulating material 36. In the example shown in FIG. 8 , the hollow portions are located near the opposing first one-side edge portion 11 and second one-side edge portion 21, and near the opposing first other-side edge portion 12 and second other-side edge portion 22. The first one-side edge portion 11 and second one-side edge portion 21 overlap in the circumferential direction to prevent the intrusion of rainwater and the like.

[0039] 8 (when viewed from the virtual cross section 30n shown in FIG. 4), the first other-side edge portion 12 and the second other-side edge portion 22 overlap in the circumferential direction to form a drainage gap 12s. The drainage gap 12s is formed in an unjoined portion of the opposing first other-side edge portion 12 and second other-side edge portion 22. The insulator 2 forms the drainage gap 12s, which is a gap between the first other-side edge portion 12 and the second other-side edge portion 22, and which connects the outer space K, which is the space outside the insulator 2, with the heat-shielding space 31k. The drainage direction of the drainage gap 12s is a downward direction.

[0040] As shown in FIG. 8, the dead grass intrusion path 12k, which is the path from the outer space K through the drainage gap 12s to the heat shield space 31k, is not linear but curved.

[0041] In addition, the portions of the first other edge portion 12 and the second other edge portion 22 (see Figure 8) that are located vertically below the protruding member 34 (the portions indicated by symbol 12b in Figure 2) form a drainage gap 12s (see Figure 8) without being joined to each other.

[0042] For example, if rainwater or the like infiltrates the heat-shielding space 31k between the upstream exhaust pipe 31 and the insulator 2, the infiltrating rainwater or the like moves downward by gravity and is drained through the drainage gap 12s formed by the first other-side edge portion 12 and the second other-side edge portion 22. Furthermore, since the area around the drainage gap 12s is hollow and not filled with the insulating material 36, the rainwater or the like does not remain around the drainage gap 12s and is drained through the drainage gap 12s without resistance. Furthermore, since the dead grass intrusion path 12k is curved and has a structure that makes it difficult for dead grass or the like to infiltrate, there is no need to block the drainage gap 12s with a wire mesh or the like. Furthermore, at the lowest portion of the insulator 2 (the portion vertically below the protruding member 34), the first other-side edge portion 12 and the second other-side edge portion 22 are not joined, and a drainage gap is provided across the entire lower portion, allowing for more appropriate drainage.

[0043] [Positions of the first other edge portion 12 and the second other edge portion 22 relative to the position of the protruding member 34 (FIGS. 9 to 11)] 9 shows an example in which the first other edge portion 12 and the second other edge portion 22 pass through the protruding member 34. In order to avoid interference with the socket 34a of the protruding member 34, a notch 13 is formed in the first other edge portion 12, and a notch 23 is formed in the second other edge portion 22. Note that a wire mesh 37 or the like is provided between the notch 13, the notch 23, and the socket 34a, as shown in FIG.

[0044] 10 shows an example in which the first other edge portion 12 and the second other edge portion 22 pass near the protruding member 34. A notch 13a is formed in the first other edge portion 12 to avoid interference with the socket 34a of the protruding member 34, but no notch is provided in the second other edge portion 22 because the second other edge portion 22 does not interfere with the socket 34a. A wire mesh 37 or the like is provided between the notch 13a and the socket 34a.

[0045] With the above structure, the insulator 2 can also properly cover the exhaust pipe around the protruding member 34 (the exhaust pipe including the bent portion with the protruding member). In addition, since the drainage gap 12s can be formed simply by assembling it into a cylindrical shape, there is no need to drill drainage holes in the insulator 2, and there is also no need to block the drainage gap 12s with a wire mesh or the like. This makes it possible to properly drain infiltrating rainwater and the like while suppressing an increase in the manufacturing process and the number of parts.

[0046] The insulator 2 of the present invention is not limited to the configuration, structure, appearance, etc. described in this embodiment, and various modifications, additions, and deletions are possible within the scope of the present invention.

[0047] In the description of this embodiment, an example has been given in which the opposing first one-side edge portion 11 and second one-side edge portion 21 are partially joined, but they may be joined entirely. Also, in the description of this embodiment, an example has been given in which the opposing first other-side edge portion 12 and second other-side edge portion 22 are partially joined and the remainder is not joined, but they may not be joined entirely. Also, in the description of this embodiment, an example has been given in which the first other-side edge portion 12 and second other-side edge portion 22 are not joined at a portion located vertically below the protruding member 34, but at least a portion of that portion may be joined.

[0048] In addition, in the description of this embodiment, an example has been described in Figure 8 in which the areas near the first other edge portion 12 and the second other edge portion 22 in the heat-shielding space 31k and the areas near the first one edge portion 11 and the second one edge portion 21 are made hollow, but the entire heat-shielding space 31k may be made hollow, or the entire heat-shielding space 31k may be filled with insulating material 36.

[0049] 8 is formed by overlapping the first other edge portion 12 and the second other edge portion 22 in the circumferential direction, but the drainage gap may also be formed by extending the first other edge portion 12 and the second other edge portion 22 in a substantially vertical direction and facing each other. Also, the path from the outer space K through the drainage gap to the heat-shielding space 31k may be a relatively narrow gap that is difficult for dead grass and the like to enter, without bending the path.

[0050] In addition, in the description of this embodiment, an example of the protruding member 34 has been described as a member for attaching the urea water addition valve 80b, but the protruding member 34 is not limited to a member for attaching the fuel addition valve 80a, and may also be a member for attaching various sensors and actuators.

[0051] The insulator 2 described in this embodiment can be applied to exhaust pipes of various vehicles (general vehicles, industrial vehicles, etc.) equipped with various internal combustion engines (diesel engines, gasoline engines, etc.). [Explanation of symbols]

[0052] 1 Exhaust pipe unit 2 insulators 3 Downstream insulator 10 First half insulator 10m cross section 11 First edge 12 First other edge portion 12k Dead grass invasion route 12s drainage gap 13, 13a Notch 20 Second half insulator 20m cross section 21 Second one edge 22 second other edge portion 23 Notch 30 exhaust pipe 30a Bent portion with protruding member 30m, 30n, 30p virtual cross section 31 Upstream exhaust pipe 31a Upstream end flange 31k Heat-shielded space 31u inner tube 31v Insulated space 32 Downstream exhaust pipe 32a Downstream end flange 33 Dispersion device 34 Protruding member 34a socket 34b Protruding flange (flange part) 36 Insulation 37 Wire Mesh 40 First downstream half insulator 50 Second downstream half insulator 70 vehicles 71 Internal combustion engine 72 Intake manifold 73 Supercharger 74 Exhaust manifold 75 Exhaust route 76 First Purification Device 77 NOx aftertreatment device 78 Second Purification Device 79 silencer 80a Fuel addition valve 80b Urea solution addition valve K outer space

Claims

1. A cylindrical insulator that covers a part of an exhaust pipe in an exhaust path of an internal combustion engine, the exhaust pipe covered by the insulator has a bent portion, and a protruding member is provided at the bent portion, the protruding member protruding outward from the exhaust pipe and having a flange portion at a tip thereof for attaching a device; the insulator is fixed to the exhaust pipe, covers at least the bent portion, and is formed into a cylindrical shape by combining a first half insulator and a second half insulator, each of which has an arc-shaped cross section perpendicular to a longitudinal direction of the exhaust pipe, the first half insulator has two edges along the longitudinal direction, that is, a first one edge and a first other edge, the second half insulator has two edges along the longitudinal direction, that is, a second first edge and a second second edge, At least a portion of the first one edge portion and a portion of the second one edge portion are joined together, and at least a portion of the first other edge portion and a portion of the second other edge portion are joined together, so that the insulators are assembled into a cylindrical shape, the first one edge portion and the second one edge portion are located vertically above the first other edge portion and the second other edge portion, the insulator forms a drainage gap, which is a gap between the first other edge portion and the second other edge portion, and which is a gap that communicates between a heat-shielding space, which is a space surrounded by an outer circumferential surface of the exhaust pipe and an inner circumferential surface of the insulator, and an outer space of the insulator; a notch that avoids interference with the protruding member is provided in at least one of the first other edge portion and the second other edge portion; the first other edge portion and the second other edge portion overlap in a circumferential direction when viewed in a virtual cross section perpendicular to the longitudinal direction of the exhaust pipe, thereby forming the drainage gap, When viewed in the virtual cross section, a path from the outside space through the drainage gap to the heat-shielding space is bent. Insulator.

2. An insulator as described in claim 1, The heat-shielding space is filled with a heat insulating material, At least a vicinity of the first other edge portion and a vicinity of the second other edge portion in the heat shield space are hollow portions that are not filled with the heat insulating material. Insulator.

3. An insulator as described in claim 1, The first other edge portion and the second other edge portion have portions that are positioned vertically below the protruding member and are not joined to each other, thereby forming the drainage gap. Insulator.

4. An insulator as described in claim 1, the device attached to the flange portion is an addition valve that injects a reaction liquid into the exhaust pipe, the reaction liquid being used in an exhaust purification device connected to the exhaust pipe. Insulator.

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