JP5245959B2 - Catalytic converter body mounting structure - Google Patents

Description

  The present invention relates to a vehicle body mounting structure for a catalytic converter applied to a vehicle such as a diesel engine automobile.

  Conventionally, as a catalytic converter applied to a vehicle such as a diesel engine automobile, a structure in which an alumina fiber mat is interposed between a catalyst carrier and a metal casing is known (see, for example, Patent Document 1). In this catalytic converter, the catalyst carrier is stably fixed inside the metal casing by the thermal expansion of the alumina fiber mat.

JP 9-201514 A

  However, in the catalytic converter having the above configuration, if the gap between the catalyst carrier on which the alumina fiber mat is interposed and the metal casing is too small with respect to the thickness of the alumina fiber mat, the alumina fiber mat is heated. When expanding, the catalyst carrier may be damaged by the expansion pressure. On the other hand, if the gap between the catalyst carrier in which the alumina fiber mat is interposed and the metal casing is larger than the thickness of the alumina fiber mat, the catalyst carrier cannot be stably fixed.

  In view of the above facts, the present invention has an object to obtain a vehicle body mounting structure for a catalytic converter that can prevent the catalyst carrier from being damaged and can prevent the displacement of the fixed position of the catalyst carrier in the case.

  According to a first aspect of the present invention, there is provided a vehicle body mounting structure for a catalytic converter, which is interposed between a catalyst carrier for purifying exhaust gas, a metal case for housing the catalyst carrier, and the catalyst carrier and the case. A holding member that holds the catalyst carrier; and a band that attaches the case to a vehicle body, and has a band formed at a contact portion with the case to project and deform the case toward the holding member. .

  In the catalytic converter mounting structure of the catalytic converter according to the first aspect, when the catalytic converter is fixed to the vehicle body by the band, the convex portion formed on the band hits the case, and the case is protruded and deformed toward the holding material side. As a result, the deformed part of the case compresses the holding material that is interposed between the catalyst carrier and the case and holds the catalyst carrier. For this reason, the catalyst carrier can be stably fixed. Moreover, the gap dimension between the case and the catalyst carrier can be increased with respect to the thickness of the holding material except for a portion where the deformed portion of the case protrudes and deforms toward the holding material by the band. For this reason, the catalyst carrier is not damaged by the expansion pressure when the holding material is thermally expanded.

According to a second aspect of the present invention, in the vehicle body mounting structure for a catalytic converter according to the first aspect, the case has a fragile portion at a portion in contact with the convex portion of the band.

  In the vehicle body mounting structure of the catalytic converter according to the second aspect, when the catalytic converter is fixed to the vehicle body with the band, the case is easily deformed by the fragile portion provided in the portion of the case that contacts the convex portion of the band. As a result, the catalyst carrier is securely held and the assembling workability is improved.

According to a third aspect of the present invention, in the vehicle body mounting structure for a catalytic converter according to the second aspect , the weak portion is formed by a slit or a thin portion .

In the vehicle body mounting structure of the catalytic converter according to claim 3, when the catalytic converter is fixed to the vehicle body with the band, the weak portion formed by the slit or the thin portion provided in the part of the case that contacts the convex portion of the band. The case is easily deformed. As a result, the catalyst carrier is securely held and the assembling workability is improved.

According to a fourth aspect of the present invention, there is provided the catalytic converter vehicle body mounting structure according to any one of the first to third aspects, wherein the band has a heat radiating means .

In the catalytic converter vehicle body mounting structure according to the fourth aspect, the temperature of the case is lowered by the heat dissipating means provided in the band, and the thermal expansion of the case is suppressed. As a result, it is possible to suppress a decrease in the retention of the catalyst carrier due to the thermal expansion of the case.

The invention described in claim 5 is the vehicle body mounting structure of the catalytic converter according to claim 4, wherein said heat dissipating means is supported on the vehicle body floor via a support provided with a rubber mount.

  In the vehicle body mounting structure of the catalytic converter according to claim 5, since the heat radiating means of the band is supported under the vehicle body floor via the support having the rubber mount, the temperature of the case is further lowered by the heat radiation from the support. Is further suppressed. As a result, it is possible to further suppress a decrease in the retention of the catalyst carrier due to the thermal expansion of the case. Further, the number of parts can be reduced as compared with the case where the attaching means for attaching the support for supporting the catalytic converter to the vehicle body and the heat dissipating means are separate members.

  As described above, in the catalytic converter vehicle body mounting structure according to claim 1 of the present invention, it is possible to prevent the catalyst carrier from being damaged and to prevent the displacement of the fixed position of the catalyst carrier in the case.

  In the vehicle body mounting structure for a catalytic converter according to claim 2 of the present invention, the catalyst carrier can be securely held and the assembling workability can be improved.

In the vehicle body mounting structure for a catalytic converter according to claim 3 of the present invention, the catalyst carrier can be securely held and the assembling workability can be improved.

In the vehicle body mounting structure for a catalytic converter according to claim 4 of the present invention, it is possible to suppress a decrease in the holding power of the catalyst carrier due to thermal expansion of the case.

  In the vehicle body mounting structure of the catalytic converter according to claim 5 of the present invention, it is possible to further suppress a decrease in the holding power of the catalyst carrier due to the thermal expansion of the case and to reduce the number of parts.

It is the perspective view seen from the vehicle body diagonally front which shows the vehicle body mounting structure of the catalytic converter which concerns on 1st Embodiment of this invention. It is the disassembled perspective view seen from the vehicle body diagonally front which shows the vehicle body mounting structure of the catalytic converter which concerns on 1st Embodiment of this invention. FIG. 3 is a cross-sectional view taken along a line 3-3 in FIG. 1. FIG. 4 is an enlarged cross-sectional view taken along a line 4-4 in FIG. 3. FIG. 5 is a cross-sectional view corresponding to FIG. 4 illustrating a state in the middle of the assembly of the catalytic converter vehicle body mounting structure according to the first embodiment of the present invention. It is the disassembled perspective view seen from the vehicle body diagonally front which shows the vehicle body attachment structure of the catalytic converter which concerns on 2nd Embodiment of this invention. It is the disassembled perspective view seen from the vehicle body diagonally front which shows the vehicle body attachment structure of the catalytic converter which concerns on 3rd Embodiment of this invention. It is the disassembled perspective view seen from the vehicle body diagonally front which shows the vehicle body attachment structure of the catalytic converter which concerns on 4th Embodiment of this invention. It is sectional drawing corresponding to FIG. 4 which shows the vehicle body attachment structure of the catalytic converter which concerns on 4th Embodiment of this invention. It is sectional drawing corresponding to FIG. 4 which shows the vehicle body attachment structure of the catalytic converter which concerns on 5th Embodiment of this invention. It is sectional drawing corresponding to FIG. 4 which shows the vehicle body attachment structure of the catalytic converter which concerns on 6th Embodiment of this invention.

[First Embodiment]

  A first embodiment of a catalytic converter vehicle body mounting structure according to the present invention will be described below with reference to FIGS. In these drawings, an arrow UP appropriately shown indicates the upward direction of the vehicle body, and an arrow FR indicates the forward direction of the vehicle body.

(Overall configuration of exhaust system)

  An exhaust system structure in an automobile equipped with an internal combustion engine (for example, a diesel engine) is, in order from the upstream, a catalytic converter for purifying exhaust gas, and exhaust for recovering heat of exhaust gas for promoting warm-up of the engine and maintaining heating. A system heat exchanger and a muffler for reducing (muffling) exhaust noise are provided, and these devices are connected in series by an exhaust pipe.

  Among these devices, an exhaust pipe 12 connected to the upstream side of the catalytic converter 10 shown in FIG. 1 has an upstream end connected to an exhaust manifold of an internal combustion engine (not shown). Has been introduced. Further, the exhaust pipe 14 connected to the downstream side of the catalytic converter 10 is connected to an exhaust system heat exchanger (not shown).

(Composition of catalytic converter and mounting structure to the vehicle body)

  As shown in FIG. 3, the catalytic converter 10 has a catalyst carrier 20 made of an exhaust gas purifying ceramic or the like disposed in a central portion in a cylindrical shape, and is formed from an alumina fiber mat or the like so as to surround the outer periphery of the catalyst carrier 20. A holding material 22 is provided. Further, the catalyst carrier 20 and the holding material 22 are housed in a metal case 24 such as stainless steel, and the holding material 22 is interposed between the catalyst carrier 20 and the case 24 so that the catalyst carrier 20 is placed inside the case 24 in a predetermined manner. Is held in the position.

  As shown in FIG. 2, the case 24 of the catalytic converter 10 has a longitudinal direction arranged along the longitudinal direction of the vehicle body, and the longitudinal intermediate portion 24 </ b> A has a cylindrical shape. Further, the front end portion 24B of the case 24 is reduced in diameter toward the front of the vehicle body, and the front end serves as a connection portion 24C with the exhaust pipe 12. On the other hand, the rear end portion 24D of the case 24 is reduced in diameter toward the rear of the vehicle body, and the rear end serves as a connection portion 24E with the exhaust pipe 14.

  A concave portion 26 recessed inward of the case 24 is formed along the circumferential direction at the central portion in the longitudinal direction of the longitudinal intermediate portion 24 </ b> A of the case 24. A metal underband 30 for fixing the case 24 of the catalytic converter 10 to the vehicle body is engaged with the recess 26 from below. In addition, the shape of the underband 30 viewed from the front-rear direction of the vehicle body is a U-shape in which the main body portion 30A has the opening portion directed upward of the vehicle body, and extends in directions away from each other at both ends of the main body portion 30A. Attachment portions 30B are respectively formed.

  On the main body 30A of the underband 30, a convex portion 32 is formed so as to protrude toward the inner peripheral side of the main body 30A (the case 24 side of the catalytic converter 10). The convex portion 32 is continuously formed along the circumferential direction of the main body portion 30A at the central portion in the front-rear direction (the central portion in the width direction) of the main body portion 30A. Further, attachment holes 34 are formed in the attachment portions 30 </ b> B of the underband 30.

As shown in FIG. 5, the cross-sectional shape seen from the longitudinal direction (circumferential direction) of the convex portion 32 of the underband 30 is a triangular shape with a sharp tip portion 32 </ b> A. It hits the center in the width direction. In addition, the cross-sectional shape seen from the longitudinal direction (circumferential direction) of the concave portion 26 of the case 24 is a trapezoid .

  As shown in FIG. 2, flanges 30 </ b> C are formed toward the outer peripheral side at both ends in the front-rear direction of the main body 30 </ b> A of the underband 30, and these flanges 30 </ b> C are formed on the attachment portions 30 </ b> B of the underband 30. It is connected to flanges 30D formed at both ends in the front-rear direction toward the lower side of the vehicle body.

  As shown in FIG. 1, a pair of left and right support rods 42 for supporting the catalytic converter 10 with respect to the vehicle body are fixed to the lower surface 40A of the cross member 40 disposed along the vehicle width direction below the vehicle body floor. Yes. These support rods 42 are bent in a substantially U shape in a side view, and upper bent portions 42A are fixed to the lower surface 40A of the cross member 40 by welding. The lower bent portion 42B of each support rod 42 is connected to the upper portion of a support rubber 44 as a rubber mount.

  Upper bands 48 are attached to the left and right support rubbers 44 via left and right support rods 46. That is, each support rod 46 is formed in a substantially U shape in a side view, the upper bent portion 46A is connected to the lower portion of the support rubber 44, and the lower bent portion 46B is welded to the upper surface 48A of the upper band 48 by welding. It is fixed.

  As shown in FIG. 2, the upper band 48 extends linearly in the vehicle width direction, and attachment holes 50 are formed in both end portions 48B in the vehicle width direction. Bolts 54 are respectively inserted into the mounting holes 34 of the underband 30 and the mounting holes 50 of the upper band 48 from the lower side of the vehicle body toward the upper side of the vehicle body. It is fastened to a nut 56 provided at 48A.

  As shown in FIG. 3, when the bolt 54 is fastened to the nut 56, the tip 32 </ b> A of the convex portion 32 provided on the underband 30 contacts the bottom 26 </ b> A of the concave portion 26 of the case 24 as shown in FIG. 5. When the bolt 54 is further tightened into the nut 56, as shown in FIG. 4, the tip end portion 32 </ b> A of the convex portion 32 provided on the underband 30 faces the bottom portion 26 </ b> A of the concave portion 26 of the case 24 toward the holding member 22. It is designed to project and deform.

  Accordingly, the deformed portion 60 of the case 24 surrounds the outer periphery of the catalyst carrier 20, the holding material 22 interposed between the case 24 and the catalyst carrier 20 is compressed, and the holding material 22 presses the catalyst carrier 20. ing. Further, the gap dimension M1 between the case 24 and the catalyst carrier 20 can be increased except for a portion that protrudes and deforms toward the holding material 22 side by the underband 30.

  In the present embodiment, as shown in FIG. 1, each attachment portion 30B of the underband 30, the upper portion 30E of the main body portion 30A continuous to each attachment portion 30B, and the upper band 48 are caused by vehicle running wind (arrows in FIG. 1). W1) acts as a heat dissipating means for dissipating the heat of the catalytic converter 10.

  Next, the operation of this embodiment will be described.

  In the present embodiment, when the catalytic converter 10 is fixed to the cross member 40 of the vehicle body by the upper band 48 and the underband 30, when the left and right bolts 54 are fastened to the nuts 56, as shown in FIG. A front end portion 32 </ b> A of the convex portion 32 provided on 30 contacts the bottom portion 26 </ b> A of the concave portion 26 of the case 24.

  Further, when the bolt 54 is further tightened into the nut 56, as shown in FIG. 4, the tip end portion 32A of the convex portion 32 provided on the underband 30 faces the bottom portion 26A of the concave portion 26 of the case 24 toward the holding material 22 side. To project.

  As a result, the deformable portion 60 of the case 24 surrounds the outer periphery of the catalyst carrier 20, the holding material 22 interposed between the case 24 and the catalyst carrier 20 is compressed, and the holding material 22 presses the catalyst carrier 20. For this reason, the holding force of the catalyst carrier 20 by the holding material 22 is increased, and the catalyst carrier 20 can be stably fixed in the case 24. Therefore, the displacement of the catalyst carrier 20 in the case can be prevented.

  Further, the gap dimension M <b> 1 between the case 24 and the catalyst carrier 20 can be increased except for a portion where the deformed portion 60 of the case 24 protrudes and deforms toward the holding material 22 by the underband 30. For this reason, when the holding material 22 is thermally expanded, the catalyst carrier 20 is not damaged by the expansion pressure.

  Further, in the present embodiment, each attachment portion 30B of the underband 30, the upper portion 30E of the main body portion 30A continuous to each attachment portion 30B, and the upper band 48 serve as heat radiation means (cooling fins) that radiate the heat of the catalytic converter 10. Works. For this reason, the temperature rise of the catalytic converter 10 can be suppressed by the vehicle traveling wind (arrow W1 in FIG. 1). As a result, the thermal expansion of the case 24 can be suppressed, and a decrease in holding power can be suppressed even when the catalyst carrier 20 reaches a high temperature.

  In the present embodiment, the upper band 48 acting as a cooling fin is fixed to the cross member 40 of the vehicle body via the support rod 46, the support rubber 44 and the support rod 42. For this reason, since the temperature of the case 24 is further lowered by heat radiation from the support rod 46, the support rubber 44 and the support rod 42, the thermal expansion of the case 24 is further suppressed. As a result, it is possible to further suppress a decrease in the holding power of the catalyst carrier 20 due to the thermal expansion of the case 24. Further, the number of parts can be reduced as compared with the case where the attachment means for attaching the support for supporting the cross member 40 of the vehicle body and the heat dissipation means are separate members.

[Second Embodiment]

  Next, a second embodiment of the catalytic converter vehicle body mounting structure of the present invention will be described with reference to FIG.

  In addition, about the same member as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 6, in the present embodiment, a plurality of convex portions 64 having tip portions 64 </ b> A are arranged on the inner peripheral side of the main body portion 30 </ b> A at the front-rear direction center portion (width direction center) of the main body portion 30 </ b> A of the underband 30. A gap 66 is formed along the circumferential direction of the main body 30A toward the (case 24 side of the catalytic converter 10) so as to project discontinuously.

  Therefore, this embodiment also has the same function and effect as the first embodiment.

[Third Embodiment]

  Next, a third embodiment of the catalytic converter vehicle body mounting structure of the present invention will be described with reference to FIG.

  In addition, about the same member as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 7, in the present embodiment, a plurality of hemispherical convex portions 68 are formed on the inner peripheral side (catalyst) of the main body 30 </ b> A at the front-rear direction center (width-direction center) of the main body 30 </ b> A of the underband 30. A gap 70 is formed along the circumferential direction of the main body 30 </ b> A toward the case 24 side of the converter 10.

  Therefore, this embodiment also has the same function and effect as the first embodiment.

[Fourth Embodiment]

  Next, a fourth embodiment of the catalytic converter vehicle body mounting structure of the present invention will be described with reference to FIGS.

  In addition, about the same member as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 8, in this embodiment, a plurality of slits 74 are formed along the circumferential direction in the portion of the case 24 where the tip 32 </ b> A of the convex portion 32 provided on the underband 30 abuts. A fragile portion 76 is formed along.

  As shown in FIG. 9, each slit 74 passes through the case 24. Since the holding material 22 is provided on the inner peripheral side (exhaust gas passage side) of each slit 74, the exhaust gas does not leak from the slit 74 to the outside of the case 24.

  Therefore, in this embodiment, in addition to the same effect as the first embodiment, the slit 74 is provided so that the tip 32A of the convex portion 32 provided on the underband 30 comes into contact with the case 24. Further, the fragile portion 76 is easily deformed. As a result, the catalyst carrier 20 can be reliably held and the assembling workability is improved.

  In addition, it is good also as the weak part 76 by replacing with the slit 74 and forming a long hole and a round hole. Further, instead of the slit 74, a weak portion 76 may be formed by forming a thin portion along the circumferential direction at a portion of the case 24 where the tip portion 32 </ b> A of the convex portion 32 provided on the underband 30 abuts.

  [Supplementary explanation of the above embodiment]

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art. For example, the recess 26 of the case 24 may be thinner than other parts of the case 24.

  Further, as in the fifth embodiment shown in FIG. 10, the cross-sectional shape of the convex portion 32 of the underband 30 and the cross-sectional shape of the concave portion 26 of the case 24 are made the same triangular shape and pressed against the convex portion 32 of the underband 30. The recessed portion 26 of the case 24 may be further deformed to the inside of the case.

  In addition, as in the sixth embodiment shown in FIG. 11, the cross-sectional shape of the convex portion 32 of the underband 30 and the cross-sectional shape of the concave portion 26 of the case 24 are made the same trapezoidal shape and pressed against the convex portion 32 of the underband 30. The recessed portion 26 of the case 24 may be further deformed to the inside of the case.

  In each of the above embodiments, the catalytic converter 10 is supported by the cross member 40 along the longitudinal direction of the vehicle body. However, the catalytic converter 10 may be supported by other parts under the vehicle body floor other than the cross member 40. Further, the support direction of the catalytic converter 10 may be another direction such as a vehicle width direction.

DESCRIPTION OF SYMBOLS 10 Catalytic converter 20 Catalyst carrier 22 Holding material 24 Case 26 Recessed case 30 Underband 30B Underband mounting part (heat dissipation means)
30E Upper body part of underband (heat dissipation means)
32 Convex part of underband 40 Cross member (vehicle body)
42 Support rod (support)
44 Support rubber (support, rubber mount)
46 Support rod (support)
48 Upper band (heat dissipation means)
60 Deformed part of the case 64 Convex part of the band 68 Convex part of the band 74 Slit of the case 76 Fragile part of the case

Claims (5)

A catalyst carrier for exhaust gas purification;
A metal case for housing the catalyst carrier;
A holding material interposed between the catalyst carrier and the case to hold the catalyst carrier;
A band in which the case is attached to the vehicle body, and a protrusion is formed on the contact portion with the case to project and deform the case toward the holding material.
The vehicle body mounting structure of the catalytic converter which has this. 2. The vehicle body mounting structure for a catalytic converter according to claim 1, wherein the case has a fragile portion at a portion in contact with the convex portion of the band. 3. The vehicle body mounting structure for a catalytic converter according to claim 2 , wherein the fragile portion is formed by a slit or a thin-walled portion . The vehicle body mounting structure for a catalytic converter according to any one of claims 1 to 3, wherein the band has a heat radiating means . 5. The vehicle body mounting structure for a catalytic converter according to claim 4 , wherein the heat dissipating means is supported under the floor of the vehicle body via a support having a rubber mount.

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