JP2008088952A - Catalyst device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the cost of a catalyst device while ensuring required holding performance of a carrier to a case with simple structure, to prevent the occurrence of deformation of the carrier and to improve durability of a holding body. <P>SOLUTION: The catalyst device C comprises the columnar carrier 10 carrying a catalyst, a holding mat 20 mounted to the outer periphery of a peripheral wall 12 of the carrier 10 to hold the carrier 10, and a case 32 holding and storing the holding mat 20. The peripheral wall 12 has a tapered part 16 having a supported inclined face 16o, and the holding mat 20 has a tapered part 26 having an inner tapered face 26i and an outer tapered face 26o. The case 32 has a support part 36 having a support inclined face 36i. The supported inclined face 16o abuts on the inner tapered face 26i to hold the carrier 10 to the holding mat 20, and the outer tapered face 26o abuts on the support inclined face 36i to hold the holding mat 20 to the case 32. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a catalyst device including a carrier on which a catalyst is supported, a holding body that holds the carrier on the outer periphery of the carrier, and a case that holds and holds the holding body. And this catalyst apparatus is used in order to purify | clean the exhaust gas of combustion apparatuses, such as an internal combustion engine, for example.

In a catalyst device for purifying exhaust gas discharged from an internal combustion engine, in order to hold the carrier carrying the catalyst more securely, the holding body for holding the carrier or the case for containing and holding the holding body is tapered. This is known (see, for example, Patent Documents 1 and 2).
JP 2002-106337 A JP-A-11-303627

In the technique in which the holding body is tapered, the force for holding the holding body (hereinafter referred to as “holding force”) depends on the frictional force between the holding body and the case, and the case has a tapered shape. In the technique, the holding force for holding the carrier depends on the frictional force between the carrier and the holding body. However, the carrier and the holding body are held so that the carrier and the holding body are not excessively pressed from the case in the radial direction so as to be deformed and the carrier and the holding body are securely held at a predetermined position with respect to the case. In order to set this frictional force to an appropriate level in consideration of the thermal expansion and tolerance of the body and case, it is necessary to highly control the setting of dimensions and shape and the selection of materials. Cost increases.
Further, in order to make the holding body into a tapered shape, if the tapered portion is integrally formed with the carrier, the cost of the catalyst device increases because it is integrally formed and the existing carrier cannot be used. . Furthermore, if the holder or the case is tapered over the entire length in the exhaust gas flow direction, the processing cost increases.

  The present invention has been made in view of such circumstances, and with a simple structure, the cost of the catalyst device is reduced while ensuring the required holding performance of the carrier with respect to the case, and deformation of the carrier is generated. It aims at preventing this and improving the durability of the holder.

The invention according to claim 1 includes a columnar carrier on which a catalyst is supported, a holding body that is mounted on an outer periphery of a peripheral wall of the carrier and holds the carrier, and a case that holds and holds the holding body. In the catalyst device in which the catalyst promotes the reaction of the fluid flowing through the carrier, the peripheral wall has a tapered detail having a supported inclined surface inclined inward in the fluid flow direction on the outer periphery. The holding body has a positioning portion having an inner positioning surface and an outer positioning surface that are gradually reduced in diameter in the flow direction and inclined inward in the flow direction, and the case is inclined inward in the flow direction. A support portion having a support inclined surface, wherein the supported inclined surface is in contact with the inner positioning surface, the carrier is held by the holding body, and the outer positioning surface is in contact with the support inclined surface. Protection Body is a catalytic device that is held in the case.
A second aspect of the present invention is the catalyst device according to the first aspect, wherein the inner positioning surface and the outer positioning surface are tapered surfaces.
According to a third aspect of the present invention, in the catalyst device according to the first or second aspect, the carrier has a main body integrally formed with a structure on which the catalyst is supported, and a cylindrical shape fixed to the outer periphery of the main body. It is comprised from an outer cylinder, The said surrounding wall is comprised by the said outer cylinder at least among the said main body and the said outer cylinder, and the said detail is provided in the said outer cylinder.
According to a fourth aspect of the present invention, in the catalyst device according to the third aspect, the radial thickness of the outer cylinder is a specific circumference in which a radial distance between a peripheral component disposed around the case and the case is minimized. The direction position is smaller than the circumferential position other than the specific circumferential position.
According to a fifth aspect of the present invention, in the catalyst device according to the first or fourth aspect, the tapered portion, the positioning portion, and the support portion are respectively in the peripheral wall, the holding body, and the case. It is provided only in a part in the flow direction.
According to a sixth aspect of the present invention, in the catalyst device according to the third or fourth aspect, the tapered portion, the positioning portion, and the support portion are only at the downstream end portion of the outer cylinder, the holding body, and the case, respectively. It is provided.

According to the first aspect of the present invention, the carrier is positioned and held on the holding body in the flow direction by the abutted inclined surface of the tip being in contact with the inner positioning surface of the positioning portion, and the outer positioning of the positioning portion is performed. Since the surface abuts against the support inclined surface of the support portion, the holding body is positioned and held in the flow direction by the case, so that the carrier has a holding force based on the rigidity of the holding mat and a holding force based on the rigidity of the case. The rigid holding force is held at a predetermined position with respect to the case. For this reason, the case has a simple structure in which the carrier is provided with a taper, a positioning part on the holding body, and a support part on the case. The cost of the catalyst device can be reduced while ensuring the required holding performance of the carrier. Even when the carrier is held using frictional force, the frictional force can be reduced to the minimum required to prevent the carrier from rattling by increasing the rigidity holding force. Therefore, it is possible to prevent the carrier from being deformed due to excessive pressing during assembly of the carrier to the case or excessive pressing due to thermal expansion while securing the holding of the carrier at a predetermined position. Moreover, even when the rigidity holding force is increased, the holding force based on the rigidity of the holding body is reduced compared to the holding force of the case, thereby avoiding excessive deformation of the holding body and reducing its burden. Therefore, the durability of the holding body can be improved.
According to the second aspect of the present invention, since the inner positioning surface and the outer positioning surface of the positioning portion formed on the holding body are tapered surfaces, it is easy to equalize the load acting on the positioning portion, and the positioning Since a large load does not act locally on the part, the durability of the positioning part is improved, and the maintenance of the holding force due to the rigidity of the holding body can be prolonged.
According to the third aspect of the present invention, the tapered portion is a member separate from the main body integrally formed with the structure and is provided on the outer cylinder fixed to the main body. Compared to the case, it becomes easier to process, and the outer cylinder only needs to be fixed to the main body, so that an existing cylindrical carrier can be used to form a carrier having a taper. The cost of the catalytic device is reduced.
According to the fourth aspect of the present invention, since the peripheral part can be disposed close to the carrier of the catalyst device in the radial direction by the small thickness of the outer cylinder at the specific circumferential direction position, The arrangement becomes compact, and the space in which the catalyst device and peripheral parts are arranged can be reduced.
According to the fifth aspect of the present invention, the tapered portion, the positioning portion, and the support portion are provided only on a part of the peripheral wall, the holding body, and the case, respectively. Compared with the case where the surface is provided on the whole of the peripheral wall, the holding body and the case in the flow direction, the labor of the processing can be reduced, and the cost of the catalyst device is reduced.
According to the sixth aspect of the present invention, the tapered portion, the positioning portion, and the support portion are provided at the downstream ends of the outer cylinder, the holding body, and the case, respectively. Since the surface processing becomes easy, it contributes to the cost reduction of the catalyst device.

Embodiments of the present invention will be described below with reference to FIGS.
1 and 2, a catalyst device C to which the present invention is applied is an exhaust gas purification device that purifies exhaust gas generated in a vehicle internal combustion engine as a combustion device, and is provided in the exhaust device of the internal combustion engine. It is done.
In order to purify the exhaust gas, the catalyst device C has a columnar shape on which a catalyst for promoting a reaction such as oxidation or reduction of a substance such as HC or NO contained in the exhaust gas is supported. And a cylindrical shape that is mounted on the outer periphery of the peripheral wall 12 of the carrier 10 and holds the carrier 10, here a holding mat 20 as a cylindrical holding body, and contains the carrier 10 and the holding mat 20 and a combustion chamber of the internal combustion engine And a housing 30 that forms an exhaust passage through which exhaust gas discharged from 1 flows.

  The housing 30 is connected to the upstream exhaust pipe 2 and has an inlet cone 31 for guiding the exhaust gas from the combustion chamber 1 flowing into the housing 30 through the upstream exhaust pipe 2 to the inlet end surface 10i of the carrier 10, and a holding mat. A cylindrical case 32 holding 20 and an outlet cone connected to the downstream exhaust pipe 3 and for flowing purified exhaust gas flowing out from the outlet end face 10o of the carrier 10 from the housing 30 to the downstream exhaust pipe 3 It consists of 33. The cylindrical metal case 32 is connected to the metal entrance cone 31 and the exit cone 33 at the upstream end portion 32a and the downstream end portion 32b, respectively.

The carrier 10 disposed radially inward with respect to the holding mat 20 includes a lattice structure or honeycomb structure ceramic or metal structure 11 on which a catalyst is supported, and contains the structure 11 and serves as a fluid. The peripheral wall 12 forms a passage for the exhaust gas to flow through the structure 11. The inner periphery and outer periphery of the main body 10 and the inner periphery of the peripheral wall 12 have a substantially constant diameter over the entire length in the flow direction of exhaust gas in the carrier 10 (hereinafter referred to as “flow direction”).
The flow direction is the flow direction of the main flow of exhaust gas. In this embodiment, the flow direction is parallel to the central axis L of the carrier 10, the holding mat 20, and the case 32. In this embodiment, the carrier 10 and the holding mat 20 assembled to the case 32 have a central axis L common to the central axis L of the case 32.

  The peripheral wall 12 is composed of a cylindrical main body 13 that houses the structure 11, here a cylindrical main body 13, and a cylindrical outer cylinder 14 that is fixed to the outer periphery of the main body 13. While the main body 13 is integrally formed with the structure 11, a forming material different from that of the main body 13, here, cement (this cement is, for example, ceramics. One example is ceramics including cordierite. Includes a cordierite and silica gel, for example, in a ratio of 9: 1.) The outer cylinder 14 is formed over the entire circumference of the main body 13 by placing the cement on the outer periphery of the main body 13. Is done. At this time, a carrier of an existing catalyst device (corresponding to the main body 13 in this embodiment) can be used as the main body 13.

The peripheral wall 12 has, on the outer periphery thereof, a cylindrical straight portion 15 whose outer diameter is substantially constant in the flow direction, and a tapered portion 16 that extends in the flow direction and is connected to the downstream end portion 15b of the straight portion 15. . In this embodiment, the straight portion 15 and the tapered portion 16 including the upstream end portion 32 a are formed by the outer cylinder 14.
The tapered portion 16 has a supported inclined surface 16o that is inclined inward (or radially inward) in the flow direction and abuts against the tapered portion 26 of the holding mat 20 in the flow direction. The tapered portion 16 is provided over the entire circumference at the downstream end portion 14b of the outer cylinder 14, and the supported inclined surface 16o is formed by a tapered surface that gradually becomes smaller in the flow direction.
The radial direction and the circumferential direction mean a radial direction and a circumferential direction around the central axis L of the carrier 10, respectively.

  The holding mat 20 made of a mixture of ceramic fibers and vermiculite is wound around the outer periphery of the carrier 10, here, the outer periphery of the outer cylinder 14. The holding mat 20 disposed radially inward with respect to the case 32 has an inner diameter and an outer diameter that are substantially constant in the flow direction, and is in straight contact with the straight portion 15 and disposed radially outward. 25, and a tapered portion 26 which is disposed radially outward of the tapered portion 16 and gradually decreases in diameter while extending in the flow direction continuously to the downstream end portion 25b of the straight portion 25. The tapered portion 26 as a positioning portion for supporting the carrier 10 and positioning in the flow direction is an inner side as an inner positioning surface in which the supported inclined surface 16o abuts on the surface in contact with the flow direction and is inclined inward in the flow direction. It has a tapered surface 26i and an outer tapered surface 26o as an outer positioning surface that abuts and contacts the support inclined surface 36i of the case 32 in the flow direction and is inclined inward in the flow direction.

  The case 32 has an inner diameter and an outer diameter that are substantially constant in the flow direction, and is disposed radially outward of the straight portion 35 and the tapered portion 26 that are in surface contact with the straight portion 25 and disposed radially outward. And a support portion 36 composed of a tapered portion 26 that gradually extends in the flow direction while continuing to the downstream end portion 35 b of the straight portion 35. The support portion 36 that supports the holding mat 20 includes a support inclined surface 36i that is an inner inclined surface that is inclined inward in the flow direction, and an outer inclined surface 36o that is inclined inward in the flow direction. Both inclined surfaces 36i, 36o provided over the entire circumference of the case 32 are constituted by tapered surfaces.

  As described above, the tapered portion 16, the tapered portion 26, and the support portion 36 are provided only on the downstream end portions 14b, 20b, and 32b as a part in the flow direction in the outer cylinder 14, the holding mat 20, and the case 32, respectively. Therefore, the supported inclined surface 16o is only on the downstream end portion 14b of the outer cylinder 14 which is a part of the peripheral wall 12, and the support inclined surface 36i and the outer inclined surface 36o are only on the downstream end portion 20b of the holding mat 20, and the supporting inclined surface 36i. The outer inclined surface 36o is provided only at the downstream end 32b of the case 32, respectively. In the supported inclined surface 16o, the tapered surfaces 26i, 26o, and the support inclined surface 36i, the inclination angles of the surfaces in contact with each other are substantially equal.

In a state where the holding mat 20 mounted on the carrier 10 is assembled with the case 32, a pressing force is applied to the holding mat 20 radially inward by the case 32, and the holding mat 20 is attached to the outer cylinder 14. The shapes or dimensions of the carrier 10, the holding mat 20, and the case 32 are set so that the pressing force inward in the radial direction by the case 32 acts via the case 32. Therefore, the carrier 10 is held by the frictional force on the straight portion 25 of the holding mat 20 while being pressed in the radial direction, and the holding mat 20 holding the carrier 10 is pressed against the case 32 while being pressed in the radial direction. The straight portion 35 is held by frictional force.
Therefore, the three straight portions 15, 25, and 35 are portions that are held or held by frictional forces, and are friction holding portions in the carrier 10, the holding mat 20, and the case 32, respectively.

Further, the holding mat 20 has an outer taper surface 26o abutting against the support inclined surface 36i, so that the force in the flow direction acting on the holding mat 20 via the carrier 10 by the pressure of the exhaust gas, and the holding mat 20 The force in the flow direction acting on itself is received by the support portion 36 and is held at a predetermined position with respect to the case 32 by the holding force based on the rigidity of the case 32.
Then, the carrier 10 supports the inclined force 16 in the flow direction acting on the carrier 10 due to the pressure of the exhaust gas through the tapered portion 26 and the tapered portion 26 by the supported inclined surface 16o contacting the inner tapered surface 26i. It is received by the portion 36 and is held at a predetermined position with respect to the holding mat 20 and the case 32 by a holding force based on the rigidity of the holding mat 20 and the rigidity of the case 32.

  In this way, the carrier 10 has a taper 16 in addition to the friction holding force constituted by the friction force between the outer cylinder 14 and the holding mat 20 and the friction force between the holding mat 20 and the case 32. The supported inclined surface 16o abuts against the inner tapered surface 26i of the tapered portion 26, and the outer tapered surface 26o of the tapered portion 26 abuts against the support inclined surface 36i of the supporting portion 36, thereby increasing the rigidity of the holding mat 20. The holding force based on the holding force based on the rigidity of the case 32 and the holding force based on the rigidity of the case 32 is held at a predetermined position with respect to the case 32.

Next, operations and effects of the embodiment configured as described above will be described.
The peripheral wall 12 of the carrier 10 has a tapered portion 16 having a supported inclined surface 16o inclined inward in the exhaust gas flow direction on its outer periphery, and the holding mat 20 is inwardly inclined inward in the flow direction. A taper portion 26 as a positioning portion having a taper surface 26i and an outer taper surface 26o, and the case 32 has a support portion 36 having a support inclined surface 36i inclined inward in the flow direction. The supported inclined surface 16o abuts on the inner tapered surface 26i of the tapered portion 26 and the carrier 10 is positioned and held in the flow direction by the holding mat 20, and the outer tapered surface 26o of the tapered portion 26 is the supporting inclined surface of the supporting portion 36. When the holding mat 20 is positioned and held in the flow direction in the case 32 in contact with 36i, the carrier 10 is constituted by a holding force based on the rigidity of the holding mat 20 and a holding force based on the rigidity of the case 32. Due to the rigid holding force It is held in the flow direction to a predetermined position. For this reason, when the carrier 10 is held at a predetermined position with respect to the case only by frictional force by a simple structure in which the carrier 16 is provided with the tapered portion 16, the holding mat 20 is provided with the tapered portion 26, and the case 32 is provided with the support portion 36. Compared to the above, the cost of the catalyst device C can be reduced while ensuring the required holding performance of the carrier 10 with respect to the case 32.
Further, in addition to the rigid holding force, the carrier 10 is also provided by the friction holding force constituted by the friction force between the outer cylinder 14 and the holding mat 20 and the friction force between the holding mat 20 and the case 32. Since it is held at a predetermined position with respect to 32, the holding performance of the carrier 10 of the catalyst device C is further improved.
Even when the carrier 10 is held using frictional force, the rigidity holding force is increased and the ratio of the rigidity holding force is increased in the friction holding force and the rigidity holding force. Since the frictional force can be reduced to the minimum required for preventing rattling and the ratio of the frictional holding force can be reduced, the carrier 10 can be moved to the case 32 while ensuring the holding of the carrier 10 at a predetermined position. It is possible to prevent the carrier 10 from being deformed due to excessive pressing during assembly and excessive pressing due to thermal expansion. In addition, even when the rigidity holding force is increased, by reducing the holding force based on the rigidity of the holding mat 20 compared to the holding force of the case 32, excessive deformation of the holding mat 20 can be avoided and the burden is reduced. Since the size can be reduced, the durability of the holding mat 20 can be improved.

  Since both positioning surfaces formed by the inner tapered surface 26i and the outer tapered surface 26o of the tapered portion 26 formed on the holding mat 20 are tapered surfaces, the load acting on the tapered portion 26 as the positioning portion can be equalized. As a result, a large load does not act locally on the tapered portion 26, so that the durability of the tapered portion 26 is improved, and the maintenance of the holding force due to the rigidity of the holding mat 20 can be prolonged.

The carrier 10 includes a main body 13 that is integrally formed with the structure 11 on which the catalyst is supported, and a cylindrical outer cylinder 14 that is fixed to the outer periphery of the main body 13. The peripheral wall 12 includes the main body 13 and the outer cylinder 14. Are formed by at least the outer cylinder 14, and the tapered portion 16 is provided on the outer cylinder 14, so that the tapered portion 16 is a member separate from the main body 13 integrally formed with the structure 11, and is formed on the main body 13. Since it is provided on the outer cylinder 14 to be fixed, it is easier to process than the case where the tapered portion 16 is integrally formed with the main body 13, and the outer cylinder 14 only needs to be fixed to the main body 13, so that the existing Since the carrier 10 having the tapered portion 16 can be formed by using the cylindrical carrier, the cost of the catalyst device C is reduced.
Further, since the outer cylinder 14 is formed by placing cement as a forming material on the outer periphery of the main body 13, the outer cylinder 14 can be easily formed, and the cost can be further reduced.

The tapered portion 16, the taper portion 26, and the support portion 36 are provided only at the downstream end portions 14b, 20b, and 32b, which are parts of the outer tube 14, the holding mat 20, and the case 32 of the peripheral wall 12 in the flow direction, respectively. The tapered portion 16, the taper portion 26, and the support portion 36 are provided only on a part of the peripheral wall 12, the holding mat 20, and the case 32, respectively, so that the supported inclined surface, the inner tapered surface, the outer tapered surface, and the support are provided. Compared with the case where the inclined surface is provided on the entire peripheral wall 12, the holding mat 20 and the case 32 in the flow direction, the labor of the processing can be reduced, and the cost of the catalyst device C is reduced.
Moreover, since the tapered portion 16, the tapered portion 26 and the support portion 36 are provided on the outer cylinder 14, the holding mat 20 and the downstream end portions 14b, 20b and 32b of the case 32, respectively, the supported inclined surface 16o and the both tapered portions are provided. Since the processing of the surfaces 26i, 26o and the support inclined surface 36i is facilitated, it contributes to the cost reduction of the catalyst device C.

Hereinafter, an embodiment in which a part of the configuration of the above-described embodiment is changed will be described with respect to the changed configuration. In addition, the same code | symbol is used as needed about the member same as the member of above-mentioned embodiment, or a corresponding member.
In the embodiment shown in FIG. 3, as in the catalyst device C ₁ , the outer cylinder 14 has a plurality of tapered portions 17 having a supported inclined surface 17 o with respect to the straight portion 15 provided over the entire circumference. It may be provided at intervals in the direction. Note that the catalytic converter C ₁ has members other than the outer cylinder 14, for example, both the tapered surfaces 26i, such support 36 of the case 32 having a tapered portion 26 and the support inclined surfaces 36i of the holding mat 20 having a 26o is Since it is the same as the catalyst device C shown in FIG. 1, the same reference numerals are given in FIG.

In the embodiment shown in FIG. 4 (a), (b) , the catalytic converter C ₂ is a catalytic device of direct type, which is arranged immediately downstream of the exhaust manifold of an internal combustion engine mounted in an FF-type vehicle. In the vehicle, various engine components constituting the internal combustion engine including an intake device and an exhaust device are arranged in an engine room formed by the vehicle body. Around the catalyst device C ₂ , there are an engine body 5 of the internal combustion engine, piping such as an exhaust gas extraction tube 6 for extracting exhaust gas as EGR gas from the downstream of the catalyst device C ₂ in the exhaust gas recirculation device, Other engine components are arranged as the peripheral components arranged around the housing 30 or the case 32. Therefore, the catalyst system C _2, the radial thickness t of the outer cylinder 14, in particular circumferential position P the radial distance d between the peripheral part and the casing 32 is minimized, other than the particular circumferential position P It is set smaller than the circumferential position.

More specifically, FIG. 4 (a), in particular circumferential position P or near the radial distance d between the catalytic converter C ₂ or case 32 is opposed by the engine body 5 in the radial direction in the smallest position The thickness t of the outer cylinder 14 is the smallest. Therefore, minute thickness t is small, so that the holding mat 20 and the case 32 is located near the center axis L, are arranged in close proximity engine body 5 and the catalytic converter C ₂ Toga径direction, they The arrangement becomes compact.
Further, in FIG. 4B, the exhaust gas extraction pipe 6 at the position where the radial distance d with respect to the case 32 is the minimum among the plurality of the engine body 5 and the exhaust gas extraction pipe 6 as the peripheral parts. The thickness t of the outer cylinder 14 is the smallest at a specific circumferential position P facing in the radial direction or in the vicinity thereof. Therefore, minute thickness t is small, with an exhaust gas take-out pipe 6 and the catalytic converter C ₂ are disposed close, their arrangement can be made compact. Further, also in the circumferential direction position P ₁ facing in the engine body 5 radially, the thickness t is smaller than the maximum thickness ta of the outer cylinder 14, correspondingly, the proximity and the engine body 5 and the catalytic converter C ₂ Arranged.
As described above, in the embodiment shown in FIGS. 4A and 4B, the thickness t of the outer cylinder 14 at the specific circumferential position P is smaller than the maximum thickness ta, and in particular, the specific circumferential position P or its position. since the minimum in the vicinity, since the engine main body 5 or the exhaust gas take-out pipe 6 can be disposed close radially to the catalytic converter C ₂ or case 32, the catalyst device C ₂ and the engine body 5 or exhaust gas The arrangement of the extraction pipe 6 becomes compact, and the space in which the catalyst device C ₂ , the engine body 5 or the exhaust gas extraction pipe 6 is arranged, in this case, the engine room can be reduced.
Further, in this embodiment, the peripheral component may be a dashboard that is a partition wall between the engine room and the vehicle compartment in the vehicle.

In the embodiment shown in FIG. 5, the catalytic device C ₃ includes a tapered portion 16 and a tapered portion at the downstream end portions 14 b, 20 b, and 32 b in the outer cylinder 14, the holding mat 20, and the case 32, respectively. 26 and a support portion 36, and each upstream end portion 14a, 20a, 32a is also supported inclining inwardly in a direction opposite to the flow direction (hereinafter referred to as "anti-flow direction"). A tapered portion 66 having a surface 56o, a tapered portion 66 as a positioning portion having an inner tapered surface 66i and an outer tapered surface 66o inclined inward in the counterflow direction, and a support inclined surface 76i inclined inward in the counterflow direction. And a support portion 76 having an outer inclined surface 76o. Each inclined surface 56o, 76i, 76o is a tapered surface.
As a result, the carrier 10 is positioned and held in the flow direction and the counter-flow direction, so that the catalyst device C ₃ is caused by exhaust pulsation acting on the carrier 10 or vibrations transmitted from the vehicle body through the engine body. Even when the carrier vibrates, the carrier 10 is more securely held at a predetermined position, and the holding performance of the carrier 10 is further improved.

  Inclined supported inclined surfaces 16o and 56o, inner tapered surfaces 26i and 66i as inclined inner positioning surfaces, outer tapered surfaces 26o and 66o as inclined outer positioning surfaces, inclined supporting inclined surfaces 36i and 76i, and inclined outer surfaces In the above-described embodiment, the inclined surfaces 36o and 76o are tapered surfaces in which the cross-sectional shape of each surface in a plane including the central axis L is a straight line, but the cross-sectional shape is a surface that is an arc or a curve other than an arc. There may be.

The tapered portions 16, 17, the tapered portion 26 or the support portion 36 may be provided in a portion other than the downstream end portions 14 b, 20 b, 32 b in the outer cylinder 14, the holding mat 20, and the case 32.
The tapered portions 16 and 17 may be formed by cutting the outer cylinder 14. When the peripheral wall 12 is constituted by the main body 13 and the outer cylinder, the taper may be provided at a downstream end portion that is a part of the main body 13.
In the peripheral wall 12, the outer cylinder 14 may surround the entire outer periphery of the main body 13.
In the carrier 10, the structure 11 and the main body 13 may be formed of separate members. Further, the main body 13 and the outer cylinder 14 may be integrally formed. With regard to the columnar carrier, the “columnar shape” includes those having a hollow portion, that is, a cylindrical shape.
Although the internal combustion engine is used for a vehicle in the embodiment, it may be used for a ship propulsion device such as an outboard motor having a crankshaft oriented in the vertical direction.
The fluid flowing through the carrier 10 of the catalyst device may be a gas or a liquid other than the exhaust gas. The catalyst device may be used in devices other than the combustion device.

It is a figure which shows a part of catalyst apparatus to which this invention was applied in a cross section. It is the II-II sectional view taken on the line of FIG. FIG. 5 is a view of a main part of a catalyst device including another carrier according to another embodiment of the present invention and having a carrier having a shape different from that of the catalyst device of FIG. 1. Fig. 4 shows another embodiment of the present invention, in which (a) is a schematic view showing the arrangement of an engine body and a catalyst device shown in a cross-section corresponding to Fig. 2, and (b) is an engine body; FIG. 3 is a schematic diagram showing an arrangement of an exhaust gas extraction pipe and a catalyst device shown in a cross section corresponding to FIG. 2. FIG. 6 shows still another embodiment of the present invention and corresponds to FIG.

Explanation of symbols

10 ... carrier, 11 ... structure, 12 ... peripheral wall, 13 ... main body, 14 ... outer cylinder, 16, 17 ... tip, 16o, 56o ... supported inclined surface, 20 ... holding mat, 26 ... taper part, 26i, 66i ... inner tapered surface, 26o, 66o ... outer tapered surface, 32 ... case, 36 ... support portion, 36i, 76i ... support inclined surface,
C, C _{1 to} C ₃ ... catalytic device, d ... radial distance.

Claims (6)

A columnar carrier on which a catalyst is supported; a holder that is mounted on an outer periphery of a peripheral wall of the carrier to hold the carrier; and a case that holds and holds the holder, and the catalyst circulates the carrier. In the catalyst device for promoting the reaction of the fluid that
The peripheral wall has a tapered portion having a supported inclined surface inclined inward in the fluid flow direction on the outer periphery, and the holding body gradually decreases in diameter in the flow direction and is inward in the flow direction. A positioning portion having an inner positioning surface and an outer positioning surface that are inclined in the direction; and the case has a support portion having a supporting inclined surface that is inclined inward in the flow direction, and the supported inclined surface is the The catalyst device, wherein the carrier is held by the holding body in contact with an inner positioning surface, and the outer positioning surface is in contact with the inclined support surface and the holding body is held in the case.   The catalyst device according to claim 1, wherein the inner positioning surface and the outer positioning surface are tapered surfaces.   The carrier is composed of a main body integrally formed with the structure on which the catalyst is supported, and a cylindrical outer cylinder fixed to the outer periphery of the main body, and the peripheral wall is formed of the main body and the outer cylinder. The catalyst device according to claim 1, wherein at least the outer cylinder is provided, and the tapered portion is provided in the outer cylinder.   The radial thickness of the outer cylinder is a specific circumferential position where the radial distance between the peripheral component arranged around the case and the case is the smallest, compared to a circumferential position other than the specific circumferential position. 4. The catalyst device according to claim 3, wherein the catalyst device is small.   The taper portion, the positioning portion, and the support portion are provided only on a part of the peripheral wall, the holding body, and the case in the flow direction, respectively. The catalyst device as described.   5. The catalyst device according to claim 3, wherein the tapered portion, the positioning portion, and the support portion are provided only at a downstream end portion of the outer cylinder, the holding body, and the case, respectively.

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