exhaust purification device

Abstract

To suppress positional deviation of a heat insulator.SOLUTION: The exhaust emission control device for purifying exhaust gas of a vehicle includes an exhaust pipe, a heat insulator, a buffer, and at least one protrusion. The exhaust pipe stores an emission control member for purifying the exhaust gas. The heat insulator is arranged in such a manner of surrounding an outer peripheral surface of the exhaust pipe. The buffer is provided between the heat insulator and the outer peripheral surface of the exhaust pipe. The protrusion is provided on the outer peripheral surface of the exhaust pipe. The buffer has at least one storage space for storing the protrusion.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an exhaust purification device. [Background technology]

[0002] As described in Patent Document 1, there are known techniques for catalytic converters, such as providing a heat insulator that covers the outer peripheral surface of the exhaust pipe that houses the catalyst, or providing a heat-resistant mat material between the outer peripheral surface of the exhaust pipe and the heat insulator. Also, there is known a technique for holding the heat insulator in such catalytic converters by applying surface pressure from the mat material to the heat insulator. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-74039 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the heat insulator is held by surface pressure from the mat material, there is a risk that the heat insulator may become displaced due to vibrations of the vehicle or the like. An object of one aspect of the present disclosure is to suppress misalignment of a heat insulator. [Means for solving the problem]

[0005] One aspect of the present disclosure is an exhaust purification device configured to purify exhaust gas from a vehicle, comprising an exhaust pipe, a heat insulator, a buffer portion, and at least one protrusion portion. The exhaust pipe is configured to house a purification member that purifies the exhaust gas. The heat insulator is arranged to surround the outer peripheral surface of the exhaust pipe. The buffer portion is provided between the heat insulator and the outer peripheral surface of the exhaust pipe. The protrusion portion is provided on the outer peripheral surface of the exhaust pipe. The buffer portion has at least one accommodation space that houses the protrusion portion.

[0006] According to the above configuration, the protrusion provided on the exhaust pipe is accommodated in the accommodation space of the buffer part, which prevents the buffer part from shifting in position relative to the exhaust pipe, thereby preventing the heat insulator located outside the buffer part from shifting in position.

[0007] In one embodiment of the present disclosure, the top of the protrusion may be formed with a top surface that spreads out like a plane. According to the above configuration, when the protruding portion comes into contact with the buffer portion, damage to the buffer portion can be suppressed.

[0008] In one aspect of the present disclosure, the accommodation space may be a hole-like space in the buffer portion. According to the above configuration, the accommodation space can be suitably formed. In one aspect of the present disclosure, the heat insulator may have first and second groove portions that are groove-shaped portions, and the first and second groove portions may have first and second side edge portions, respectively. The first and second groove portions may be arranged to go around the outer circumferential surface of the exhaust pipe by arranging the first and second side edge portions of the first groove portion so as to face the first or second groove portion of the second groove portion, respectively. The buffer portion may have first and second buffer portions, and the first and second buffer portions may be arranged in the first and second groove portions, respectively. The accommodation space may be formed by a gap between an end of the first buffer portion and an end of the second buffer portion.

[0009] According to the above configuration, the accommodation space can be provided more simply. In one aspect of the present disclosure, the accommodating space may penetrate the buffer portion. The heat insulator may further include at least one connecting portion that is provided on the heat insulator, that is coupled to the protrusion, and that is accommodated in the accommodating space. The protrusion may be accommodated in the accommodating space while coupled to the connecting portion.

[0010] According to the above configuration, the positional deviation of the insulator can be more suitably suppressed. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a side view of an exhaust gas purification device according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 2 is a perspective view of a protrusion according to the first embodiment. [Figure 4] FIG. 10 is a perspective view of a protrusion of a modified example. [Figure 5] FIG. 10 is a side view of a modified exhaust gas purification device. [Figure 6] FIG. 5 is a cross-sectional view perpendicular to the axis of an exhaust purification device according to a second embodiment. [Figure 7] 10 is an explanatory view of a protruding portion in an exhaust purification device according to a third embodiment. FIG. [Figure 8] 10 is an explanatory diagram of a protruding portion and a connecting portion in an exhaust gas purification device according to a fourth embodiment. FIG. [Figure 9] 10 is an explanatory view of a protruding portion and a connecting portion in an exhaust gas purification device according to a fifth embodiment. FIG. [Figure 10] FIG. 13 is an explanatory view of a protruding portion and a connecting portion in an exhaust purification device according to a modified example of the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Note that the embodiments of the present disclosure are not limited to the following embodiments, and various forms may be adopted as long as they fall within the technical scope of the present disclosure.

[0013] [First embodiment] [1. Overview] The exhaust gas purification device 1 of the first embodiment is provided in a flow path of exhaust gas from an internal combustion engine of a vehicle and is configured to purify the exhaust gas (see FIGS. 1 and 2). As an example, the exhaust gas purification device 1 is configured as a catalytic converter and is provided adjacent to the downstream side of the exhaust manifold of the internal combustion engine.

[0014] The exhaust purification device 1 includes a purification member 2, a converter section 3, and a heat insulating device. The purification member 2 is a member for purifying exhaust gas, and may be configured as a catalyst that reforms or captures pollutants in the exhaust gas by coming into contact with the exhaust gas, for example.

[0015] The converter section 3 is configured as an exhaust pipe that forms a flow path for exhaust gas from the internal combustion engine, and houses the purification member 2 inside. Note that, as one example, the purification member 2 may be cylindrical. As one example, the converter section 3 is configured as a cylindrical portion that extends straight along the axis 10 of the purification member 2. Note that, as one example, the axis 10 passes through or near the center of a cross section of the purification member 2 that is perpendicular to the axis 10. Furthermore, the shape of the exhaust pipe is not limited to this and can be determined as appropriate.

[0016] The heat shield device is configured to block heat radiation from the converter section 3 and includes a heat insulator 4 and a buffer section 5. [2. Heat insulator] The heat insulator 4 is a substantially cylindrical member that surrounds the converter section 3 while leaving a gap with respect to the outer peripheral surface of the converter section 3 (see FIGS. 1 and 2). The heat insulator 4 is made of, for example, stainless steel or aluminum, and suppresses heat radiation from the exhaust pipe. The heat insulator 4 is disposed to surround the converter section 3, and its cross section perpendicular to the axis 10 (hereinafter simply referred to as the cross section) is, for example, circular.

[0017] The heat insulator 4 includes first and second groove portions 40, 41 which are groove-shaped portions. The first and second groove portions 40, 41 each have, for example, an arc-shaped (for example, semicircular) cross section and have first and second side edge portions 40A, 40B, 41A, 41B extending in the direction of the axis 10 (in other words, the flow direction of exhaust gas). The first and second side edge portions 40A, 40B, 41A, 41B are located at both ends of the cross section of the first and second groove portions 40, 41.

[0018] The first and second side edge portions 40A, 40B, 41A, 41B of the first and second groove portions 40, 41 are each provided with, for example, two flange portions 42. The first and second groove portions 40, 41 are arranged so that the first side edge portions 40A, 41A face each other, and the second side edge portions 40B, 41B face each other, and the flange portions 42 provided on the facing edges are joined together. Note that the joining may be, for example, mechanical joining using bolts and nuts, joining by welding, or joining by adhesive. Furthermore, joining by a combination of these methods may also be used.

[0019] [3.Buffer section] The buffer section 5 is disposed between the inner peripheral surface of the heat insulator 4 and the outer peripheral surface of the converter section 3, and is provided so as to surround the converter section 3 (see FIGS. 1 and 2). The buffer section 5 includes first and second mat members 50 and 51. The first and second mat members 50 and 51 are disposed so as to cover the inner peripheral surfaces of the first and second groove portions 40 and 41 of the heat insulator 4, respectively, and the cross sections of the first and second mat members 50 and 51 are arc-shaped.

[0020] Moreover, as one example, the first and second mat members 50, 51 are bonded to the outer peripheral surface of the converter section 3 or the inner peripheral surface of the heat insulator 4 by an adhesive. Of course, this is not limiting, and the first and second mat members 50, 51 may be fixed to the converter section 3 or the heat insulator 4 by means other than an adhesive, or the first and second mat members 50, 51 may not be fixed to the converter section 3 or the heat insulator 4.

[0021] The first and second mat materials 50, 51 are configured as buffer materials and contain, for example, a material with a lower thermal conductivity than air (e.g., glass wool or rock wool), which provides a heat-shielding function. Of course, the first and second mat materials 50, 51 are not limited to these materials and can be configured from various materials.

[0022] Here, the portions located at both ends of the cross section of the first and second mat members 50, 51 are referred to as first and second end portions 50A, 50B, 51A, 51B, respectively. The first and second mat members 50, 51 are arranged so that the first end portions 50A, 51A face each other and the second end portions 50B, 51B face each other. Furthermore, gaps are formed between the first end portions 50A, 51A and between the second end portions 50B, 51B.

[0023] Furthermore, the first and second mat materials 50, 51 are sandwiched in a compressed state between the heat insulator 4 and the converter section 3. Therefore, a surface pressure from the compressed first and second mat materials 50, 51 is applied to the inner peripheral surface of the heat insulator 4, thereby holding the heat insulator 4 to the converter section 3.

[0024] [4. Protrusions and storage spaces] In the first embodiment, two protrusions 30 are provided protruding from the outer peripheral surface of the converter unit 3 (see FIGS. 1 and 2). The two protrusions 30 are arranged at the same position in the direction of the axis 10, and are provided at positions facing each other across the axis 10. In other words, the protrusions 30 are arranged at intervals of approximately 180° in the circumferential direction centered on the axis 10. Furthermore, each protrusion 30 is provided near the upstream end of the converter unit 3 in the flow direction of exhaust gas.

[0025] Furthermore, each protrusion 30 is formed integrally with the converter section 3. Specifically, for example, when the converter section 3 is manufactured by casting, each protrusion 30 may be cast as part of the converter section 3. Furthermore, for example, when the converter section 3 is manufactured by press molding, each protrusion 30 may be formed as part of the converter section 3 during press molding.

[0026] The first and second mat materials 50, 51 each have a storage space 52, which is a hole-like space that penetrates the mat material. These two storage spaces 52 may be formed as hole-like spaces that do not penetrate the mat materials 50, 51 but have openings adjacent to the outer peripheral surface of the converter section 3. The two storage spaces 52 are also provided at positions facing each other across the axis 10, similar to the protrusion section 30. As an example, each storage space 52 is provided at approximately the center of the cross section of the respective mat material.

[0027] Each protrusion 30 is accommodated in one of the accommodation spaces 52. The protrusion 30 accommodated in the accommodation space 52 is in contact with or in close proximity to a portion of the mat material that faces the accommodation space 52 (hereinafter, referred to as a wall surface). In other words, the accommodation space 52 is larger than or equal to the size of the protrusion 30.

[0028] Specifically, each protrusion 30 has a truncated cone shape, for example, and a flat top surface 31 is formed at the top of each protrusion 30 (see FIG. 3). Alternatively, each protrusion 30 may have a truncated pyramid shape, for example, in which the cross section perpendicular to the protrusion direction is polygonal, or may have a quadrangular truncated pyramid shape with a quadrangular top surface 31, as shown in FIG. 4. Furthermore, without being limited to this, a curved top surface may be formed at the top of each protrusion 30.

[0029] Furthermore, when the protrusion 30 has a quadrangular pyramid shape, the protrusion 30 may be disposed so that a side of the quadrangular cross section perpendicular to the protruding direction intersects with the predicted direction of displacement of the heat insulator 4. Specifically, for example, when the cross section of the protrusion 30 is rectangular and the heat insulator 4 is predicted to be displaced in the circumferential direction around the axis 10, the protrusion 30 may be disposed so that the long side of the cross section intersects with the circumferential direction as shown in Fig. 5 .

[0030] The shape of each protrusion 30 may be, for example, cylindrical or prismatic. The number of protrusions 30 and accommodation spaces 52 may be one or three or more. The positions of the protrusions 30 and accommodation spaces 52 in the direction of the axis 10 and the positions in the circumferential direction about the axis 10 can be determined as appropriate.

[0031] [Second embodiment] [5. Overview] The exhaust gas purification device 1 of the second embodiment has a configuration similar to that of the first embodiment, but differs from that of the first embodiment in the configuration of the accommodation space 52 for the first and second mat materials 50, 51. The following describes the exhaust gas purification device 1 of the second embodiment, focusing on the differences from the first embodiment.

[0032] In the second embodiment, the first and second mat members 50, 51 are not provided with hole-like storage spaces, and two storage spaces 52 are formed by gaps between the ends of the mat members (see FIG. 6). Specifically, the storage space 52 is formed by a gap between a first end portion 50A of the first mat member 50 and a first end portion 51A of the second mat member 51. Furthermore, the storage space 52 is formed by a gap between a second end portion 50B of the first mat member 50 and a second end portion 51B of the second mat member 51. In the second embodiment, the two storage spaces 52 are also provided at positions facing each other across the axis 10, as in the first embodiment.

[0033] Each protrusion 30 is accommodated in one of the accommodation spaces 52. Furthermore, the protrusion 30 accommodated in each accommodation space 52 is in contact with or close to the wall surface formed by each end of the first and second mat materials 50, 51.

[0034] [Third embodiment] [6. Overview] The exhaust purification device 1 of the third embodiment has a configuration similar to that of the first embodiment, but differs from the first embodiment in the configuration of the protrusion 30 of the converter portion 3 and the configuration of the accommodation space 52 for the first and second mat materials 50, 51. The following describes the exhaust purification device 1 of the third embodiment, focusing on the differences from the first embodiment.

[0035] In the third embodiment, each protrusion 30 is formed by joining another member (for example, a wire mesh) to the converter section 3 (see FIG. 7). Each storage space 52 is formed as a hole-like space that does not penetrate the mat material and has an opening facing the outer peripheral surface of the converter section 3.

[0036] The top surfaces 31 of the protrusions 30 accommodated in each accommodation space 52 abut against the portion of the mat material that forms the bottom of the accommodation space 52. However, this is not a limitation, and a gap may be formed between the top surfaces 31 of the protrusions 30 and the mat material. Also, a gap is formed between the side surfaces of the protrusions 30 and the portion of the mat material that is adjacent to the accommodation space 52. However, this is not a limitation, and the side surfaces of the protrusions 30 may abut against the mat material.

[0037] [Fourth embodiment] [7. Overview] The exhaust purification device 1 of the fourth embodiment has a configuration similar to that of the first embodiment, but differs from the first embodiment in the configuration of the protrusion 30 of the converter section 3 and in that two connecting portions 43 are provided on the heat insulator 4. The exhaust purification device 1 of the fourth embodiment will be described below, focusing on the differences from the first embodiment.

[0038] In the fourth embodiment, each protrusion 30 is formed by welding another member (for example, a wire mesh) to the converter unit 3 (see FIG. 8). A protrusion is provided at the center of the top surface of each protrusion 30, and the top surface forms a convex portion 32.

[0039] Similarly to the first embodiment, each storage space 52 is formed as a hole-like space penetrating the mat material. Each of the first and second grooves 40, 41 of the heat insulator 4 is provided with a connecting portion 43 that protrudes from the inner peripheral surface of the groove. Each connecting portion 43 is made of, for example, a wire mesh and is welded to the inner peripheral surface of the corresponding groove. Similar to the protrusions 30, these connecting portions 43 are provided at opposing positions across the axis 10, and are accommodated in the accommodation space 52 from the outer peripheral surface side of the mat material. Each connecting portion 43 has a hole in the center of its top surface, which forms a recess 44. The recess 44 of the connecting portion 43 is capable of fitting with the protrusion 32 of the protrusion 30.

[0040] That is, the protrusions 30 and the coupling portions 43 are coupled together by fitting the convex portions 32 of the protrusions 30 into the concave portions 44 of the coupling portions 43. Then, each protrusion 30 is housed in the housing space 52 in a state where it is coupled to the coupling portions 43.

[0041] The protrusions 30 and the coupling portions 43 may be made of a material other than wire mesh, and may be joined to the converter section 3 or the heat insulator 4 by a method other than welding.

[0042] Furthermore, gaps are formed between the side surfaces of each protrusion 30 and each connecting portion 43 and the portion of the mat material adjacent to the storage space 52. However, this is not limiting, and these side surfaces may abut against the mat material.

[0043] [Fifth embodiment] 8. Overview The exhaust purification device 1 of the fifth embodiment has a configuration similar to that of the fourth embodiment, but differs from the fourth embodiment in the configuration of the protrusion 30 of the converter section 3 and the configuration of the joining portion 43 of the heat insulator 4. The following describes the exhaust purification device 1 of the fifth embodiment, focusing on the differences from the fourth embodiment.

[0044] In the fifth embodiment, each protrusion 30 is cylindrical and includes a rivet 33 and a wire mesh 34 (see FIG. 9). The rivet 33 has a head 33A, which is a disk-shaped portion having first and second surfaces, and a body 33B protruding from the center of the first surface of the head 33A. Note that, instead of the rivet 33, for example, a weld bolt may be used. The first surface of the head 33A is welded to the outer peripheral surface of the converter unit 3. Furthermore, the wire mesh 34 is provided so as to cover the second surface of the head 33A and the side surface of the body 33B, thereby forming the cylindrical protrusion 30. Note that, as an example, the wire mesh 34 may be welded to the head 33A.

[0045] Each coupling portion 43 is cylindrical, for example, and is formed by recessing a groove toward the converter portion 3 (in other words, toward the inside). The center of the top surface of each coupling portion 43 is recessed so as to protrude outward, thereby forming a recess 44 on the top surface.

[0046] When the protrusions 30 are press-fitted into the recesses 44 of the connecting portions 43, the wire mesh 34 of the protrusions 30 is deformed, and the wire mesh 34 and the body 33B of the rivet 33 are inserted into the recesses 44. This joins the protrusions 30 and the connecting portions 43. Each protrusion 30 is housed in the housing space 52 while connected to the connecting portions 43.

[0047] Alternatively, each protrusion 30 may be formed by welding a cylindrical wire mesh 34 to the outer peripheral surface of the converter section 3 (FIG. 10). Similarly, the wire mesh 34 (in other words, the protrusion 30) may be press-fitted into the recess 44 of the connecting section 43, and the wire mesh 34 may be deformed to connect the protrusion 30 and the connecting section 43.

[0048] Alternatively, for example, each protrusion 30 may be formed only from the rivet 33, or may be formed from a member other than the rivet 33 or the wire mesh 34. Furthermore, each protrusion 30 may be joined to the converter section 3 by a method other than welding. Furthermore, each joining section 43 may be formed by joining another member to a groove in the heat insulator 4.

[0049] Furthermore, gaps are formed between the side surfaces of each protrusion 30 and each connecting portion 43 and the portion of the mat material adjacent to the storage space 52. However, this is not limiting, and these side surfaces may abut against the mat material.

[0050] [9. Effects] (1) In the first to fifth embodiments, the protrusions 30 provided on the converter unit 3 are accommodated in the accommodation spaces 52 provided in the buffer unit 5, thereby preventing the buffer unit 5 from shifting in position relative to the converter unit 3. This prevents the heat insulator 4 located outside the buffer unit 5 from shifting in position.

[0051] (2) Each protrusion 30 has a top surface 31. This prevents the protrusion 30 from damaging the mat material when it comes into contact with the mat material. (3) In the first and second embodiments, each protrusion 30 is formed integrally with the converter section 3. This makes it easier to form each protrusion 30, and simplifies the manufacturing process of the exhaust purification device 1.

[0052] (4) In addition, in the third to fifth embodiments, each protrusion 30 is formed by joining another member, such as a wire mesh or a rivet, to the outer peripheral surface of the converter section 3. This allows the protrusions 30 to be formed in various shapes and made of various materials, thereby improving the functionality of the protrusions 30. Furthermore, when the protrusions 30 are formed integrally with the converter section 3, a dedicated mold may be required. However, when the protrusions 30 are formed by joining another member to the outer peripheral surface of the converter section 3, a dedicated mold is not required, and the protrusions 30 can be formed using more general-purpose equipment.

[0053] (5) In the first and third to fifth embodiments, the storage space 52 is a hole-shaped space provided in the mat material, which allows the storage space 52 to be formed in a suitable manner. (6) In the fourth and fifth embodiments, each protrusion 30 is housed in the housing space 52 while being coupled to the coupling portion 43 provided on the heat insulator 4. This makes it possible to more effectively prevent the heat insulator 4 from being displaced.

[0054] (7) In the second embodiment, the storage space 52 is formed by a gap between the end of the first mat material 50 and the end of the second mat material 51. This makes it possible to provide the storage space 52 more easily.

[0055] 10. Other Embodiments (1) In the exhaust purification device 1 of the first to fifth embodiments, the buffer section 5 includes first and second mat materials 50, 51. However, the buffer section 5 may be configured, for example, by one mat material provided so as to surround the outer peripheral surface of the converter section 3, or may be configured by three or more mat materials arranged side by side so as to surround the outer peripheral surface of the converter section 3. Note that when the buffer section 5 is configured by three or more mat materials, an accommodation space 52 may be provided in each mat material, and a protrusion may be accommodated in each accommodation space 52.

[0056] (2) Multiple functions of one component in the above embodiments may be realized by multiple components, or one function of one component may be realized by multiple components. Also, multiple functions of multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Also, part of the configuration of the above embodiments may be omitted. Also, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0057] [11. Correspondence of Wording] The first and second mat members 50 and 51 correspond to examples of first and second buffer portions, respectively. [Explanation of symbols]

[0058] 1...exhaust gas purification device, 10...axis, 2...purification member, 3...converter portion, 30...projection portion, 31...top surface, 4...heat insulator, 40, 41...first and second groove portions, 40A, 41A...first side edge portion, 40B, 41B...second side edge portion, 43...joint portion, 5...buffer portion, 50, 51...first and second mat material, 50A, 51A...first end portion, 50B, 51B...second end portion, 52...accommodation space.

Claims

1. An exhaust gas purification device configured to purify exhaust gas from a vehicle, an exhaust pipe configured to accommodate a purification member that purifies exhaust gas; a heat insulator disposed around an outer circumferential surface of the exhaust pipe; a buffer portion provided between the heat insulator and an outer peripheral surface of the exhaust pipe; at least one protrusion provided on an outer peripheral surface of the exhaust pipe, The buffer portion has at least one accommodation space for accommodating the protrusion portion. Exhaust purification device.

2. The exhaust gas purification device according to claim 1, The top of the protrusion has a top surface that spreads out like a plane. Exhaust purification device.

3. The exhaust gas purification device according to claim 1 or 2, The accommodation space is a hole-shaped space in the buffer portion. Exhaust purification device.

4. The exhaust gas purification device according to claim 1 or 2, the heat insulator has first and second groove portions which are groove-shaped portions, the first and second groove portions having first and second side edge portions, respectively; the first and second side edge portions of the first groove portion are disposed to face the first or second edge portion of the second groove portion, respectively, so that the first and second groove portions are disposed to go around the outer circumferential surface of the exhaust pipe; the buffer portion includes first and second buffer portions, the first and second buffer portions being disposed in the first and second groove portions, respectively; The accommodating space is formed by a gap between an end of the first buffer portion and an end of the second buffer portion. Exhaust purification device.

5. The exhaust gas purification device according to claim 1 or 2, The accommodation space passes through the buffer portion, the heat insulator further includes at least one coupling portion that is coupled to the protrusion and is accommodated in the accommodation space; The protrusion is accommodated in the accommodation space while being coupled to the coupling portion. Exhaust purification device.

6. An exhaust purification device according to claim 1 or claim 2, The accommodation space is a space that penetrates the buffer portion, The protrusion does not come into contact with the heat insulator. Exhaust purification device.

7. An exhaust purification device according to claim 1 or claim 2, The accommodation space is a space that does not penetrate the buffer portion, A part of the buffer portion is disposed between the protrusion portion accommodated in the accommodation space and the heat insulator. Exhaust purification device.

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