JPH08303237A - Catalyst support metal fitting, seal and support metal fitting using the same, and method for manufacturing catalyst support metal fitting - Google Patents

Abstract

PURPOSE: To improve holding ability of a sealing material through improvement of the axial expansion contraction characteristics of a catalyst support fitting, to prevent breakage, damage of a metallic fine wire, and to prevent incurring of a flow loss of the sealing material. CONSTITUTION: A catalyst support fitting comprises a corrugated peripheral wall mounted in a stretched state between the outer peripheral surface of a monolith carrier and the inner periphery of a casing. At least one pair of holding parts 11 are arranged with a specified distance in the axial direction therebetween and manufactured by knitting or weaving a metallic fine wire. The end parts of the holding parts 11 positioned facing each other are caused to effect gradation to the vicinity of the inner peripheral end of a holding part 11. The catalyst support fitting comprises a stepped part 12 manufactured by knitting or weaving a metallic fine wire and connected to the holding parts 11; and a coupling part 13 to intercouple the inner peripheral parts of the adjoining stepped parts 12 through a plurality of curved metallic fine wires connected to the stepped part 12. An annular groove 16 for mounting a sealing material consists of the adjoining stepped parts 12 and the coupling part 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalyst support metal fitting in a monolith type catalytic converter and a seal / support metal fitting used therein.

[0002]

2. Description of the Related Art Generally, a catalytic converter is provided in the middle of an exhaust passage of an automobile engine to purify harmful components such as HC, CO and NOx contained in the exhaust gas. Catalytic converters are classified into pellet type and monolith type depending on the shape of the carrier that supports the catalytic substance.
Although roughly classified into types, recently, a monolith-type catalytic converter including a monolith carrier with low exhaust gas flow resistance has been widely adopted.

Basically, a monolith type catalytic converter is mounted between a substantially cylindrical monolith carrier having a plurality of communication holes formed in the axial direction, a casing covering the monolith carrier, and a casing and the monolith carrier. It is composed of a seal and a support fitting. The seal / support metal member has a function of elastically holding the monolith carrier in the casing and a function of preventing outflow of unpurified gas from the gap between the casing and the monolith carrier.

As a seal and a supporting metal fitting, Japanese Patent Publication No. 59-2
In Japanese Patent No. 6771, in a state where a rod-shaped sealing material is attached to a tubular knitted body knitted using thin metal wires, the knitted body is folded into a substantially flat plate shape and a portion other than the seal portion is corrugated. In addition, a product manufactured by connecting both ends of the knitted body so that the sealing material has an annular shape is described. Also,
In Japanese Utility Model Publication No. 3-305575, a seal / support metal fitting is composed of a catalyst support metal fitting made of a fine metal wire for elastically holding a monolith carrier with respect to a casing, and a sealing material for sealing a gap between the casing and the monolith carrier. What you have done is listed. In the catalyst support fitting described in this publication,
An annular groove is formed at an intermediate portion in the axial direction of the catalyst support metal fitting, and the groove bottom surface of the annular groove is composed of a plurality of thin metal wires arranged in parallel, and the other part is composed of a tubular knitted wire made of a thin metal wire. is there.

[0005]

In the former seal / support metal fitting, since the seal material and the knitted object are integrated,
The assemblability of the seal and supporting metal fittings during the assembly of the catalytic converter is improved, but since the seal material is surrounded by the knitted object, the contact area of the seal material with the inner surface of the casing and the outer surface of the monolith carrier is reduced, and the sealing performance is improved. And the amount of unpurified gas emitted increases.

On the other hand, in the latter sealing and supporting metal fitting, the outer peripheral surface of the sealing material is in close contact with the inner surface of the casing, and the inner peripheral surface of the sealing material also passes through the gaps between the metal wires arranged in parallel and the outer peripheral surface of the monolith carrier. Since it is in close contact with, the sealing performance is sufficiently secured. However, since the fine metal wires are arranged in parallel on the bottom surface of the annular groove, that is, the fine metal wires are arranged in a straight line, the axial extension of the catalyst support fitting is reduced, and the holding property of the sealing material is deteriorated. There is. Further, as disclosed in the publication, when the side walls of the annular groove are also formed of metal wires arranged in parallel, the distance corresponding to the depth of the annular groove when the annular groove is formed is absorbed by the extension of the metal wire itself. Therefore, if the depth of the annular groove is increased, a problem that the fine metal wire is broken or damaged occurs. In addition, if a sealant made of an inorganic fiber material mainly composed of ceramic fibers is used, it is possible that the sealant may flow away between the thin metal wires.

An object of the present invention is to improve the axial expansion and contraction characteristics of the catalyst support fitting to enhance the holding property of the sealing material, prevent the thin metal wires from being broken or damaged, and prevent the sealing material from flowing out. It is an object of the present invention to provide a seal / support metal fitting using the same, and a method for manufacturing a catalyst support metal fitting that allows continuous and easy manufacture of the catalyst support metal fitting.

[0008]

A catalyst support metal fitting according to claim 1 is mounted between a monolith carrier and a casing that covers the monolith carrier to elastically retain the monolith carrier with respect to the casing and between the monolith carrier and the casing. A cylindrical catalyst support metal fitting made of a thin metal wire that holds a sealing material that seals the gap between the outer peripheral surface of the monolith carrier and the inner peripheral surface of the casing. , A holding portion which is provided at least one pair at a constant interval in the axial direction and is made by knitting or weaving thin metal wires, and the ends of the holding portions facing each other are stepped down to near the inner peripheral end of the holding portion. Made by knitting or weaving thin wires,
The sealing member is provided with a step portion connected to the holding portion and a connecting portion connecting the inner peripheral end portions of the adjacent step portions with a plurality of curved metal thin wires connected to the step portion, and the adjacent step portion and the connecting portion. An annular groove for mounting is formed.

Here, as described in claim 2, an annular deformation absorbing portion continuous with the step portion may be formed by knitting or weaving fine metal wires at both ends of the connecting portion.

A seal / support metal fitting according to a third aspect of the present invention is a seal material mainly comprising a catalyst support metal element according to the first or second aspect and a ceramic fiber material mounted in an annular groove of the catalyst support metal element. The outer peripheral surface is provided on the inner peripheral surface of the casing, and the inner peripheral surface is provided with a sealing material which is mounted in close contact with the outer peripheral surface of the monolith carrier through the gaps between the thin metal wires forming the connecting portion. is there.

According to a fourth aspect of the present invention, in the method for manufacturing a catalyst support metal fitting, when knitting a metal thin wire into a tubular shape by knitting, knitting in a certain area facing each other in the circumferential direction is interrupted and the eyes are skipped. A knitting step of knitting to produce a tubular knit object in which a braided portion made of a knitted fabric extending in the axial direction and thin wire portions made of a plurality of curved metal thin wires are alternately formed in the circumferential direction, and a tubular knitting A folding step in which the object is folded into a flat plate shape with the center part in the circumferential direction of the braided portion as a boundary, and a band-shaped knitted object is produced,
A corrugation process of sequentially corrugating a plurality of stitches formed on a band-shaped knitted object, and cutting the corrugated band-shaped knitted object at constant lengths And a joining step of joining both ends of the direction in a superposed manner.

[0012]

In the catalyst support metal fitting according to claim 1, the catalyst support metal fitting is mounted on the outer peripheral portion of the monolith carrier, and
With the sealing material installed in the annular groove of the catalyst support fitting, assemble these into the casing to hold the monolith carrier in the casing through the catalyst support fitting, and hold the sealing material in the gap between the monolith carrier and the casing. Will be done. The holding of the monolith carrier with respect to the casing is basically performed by at least one pair of holding portions provided at regular intervals in the axial direction. The holding portion is formed by knitting or weaving thin metal wires. Moreover, since the peripheral wall is formed in a corrugated shape, it has elasticity in the radial direction, and the holding portion is mounted in a stretched state between the outer peripheral surface of the monolith carrier and the inner peripheral surface of the casing. Then, the monolith carrier is elastically held with respect to the casing.

The gap between the casing and the monolith carrier is basically sealed with a sealing material,
Since this sealing material is mounted in the annular groove whose groove bottom surface is the connecting portion composed of a plurality of curved metal thin wires that connect the inner peripheral end portions of the adjacent step portions, the outer peripheral surface of the sealing material is the inner surface of the casing. The inner peripheral surface of the sealing material is directly adhered to the outer peripheral surface of the monolith carrier through the gap between the metal thin wires of the connecting portion. Further, since the connecting portion is composed of a plurality of curved metal thin wires, it is possible to expand and contract in the axial direction of the adjacent holding portions, and the sealing material, when mounted in the annular groove, is provided between the adjacent step portions. It is held and its movement is restricted in the axial direction.

Furthermore, since the step portion is formed by knitting or weaving, the load acting on the step portion when the holding portion is corrugated is effectively absorbed by the expansion and contraction of the step portion. Will be done. Moreover, even if a sealing material made of an inorganic fiber material mainly containing ceramic fibers is used as the sealing material, the step portion prevents the sealing material from flowing away.

According to the second aspect of the present invention, when the annular deformation absorbing portion continuous with the step portion is formed by knitting or weaving the metal thin wires at both ends of the connecting portion, the holding portion is corrugated. The load acting on the step portion when applied is also absorbed by the deformation absorbing portion. According to a third aspect of the present invention, in the seal / support metal fitting, the annular groove of the catalyst support metal fitting according to the first or second embodiment is mounted with a sealing material mainly made of a ceramic fiber material, and these are mounted on a casing of a monolithic catalytic converter. Therefore, the same effect as that of claim 1 or 2 can be obtained.

In the method of manufacturing a catalyst supporting metal fitting according to a fourth aspect of the present invention, the catalyst supporting metal fitting of the first aspect is manufactured by knitting a fine metal wire through a knitting step, a folding step, a corrugating step and a joining step. It will be. In other words, in the knitting process, the knitting is performed by interrupting the knitting in a certain area facing each other in the circumferential direction and skipping the knitting to form a portion corresponding to the connecting portion of the catalyst support metal fittings. By carrying out a corrugating process which is sequentially performed on the plurality of braided portions formed in the above, the holding portion and the stepped portion of the catalyst supporting metal fitting are formed.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a monolith catalytic converter 1 includes a substantially cylindrical monolith carrier 3 having a plurality of communication holes (see FIG. 4) 2 in the axial direction, a casing 4 covering the monolith carrier 3, and a casing. 4, a catalyst support fitting 10 for holding the monolith carrier 3 and a casing 4
And a sealing material 5 for sealing a gap 6 between the monolith carrier 3 and HC, CO, NO contained in the exhaust gas.
The harmful component such as x is configured to be purified by the catalytic substance carried on the monolith carrier 3 in the process of flowing through the communication hole 2. However, the monolithic carrier 3 in the illustrated example is of a lattice type, but it is also possible to use a spiral type or a layered type. Further, although the monolith carrier 3 having a circular cross section is used, an ellipse, an ellipse, an oval or the like may be used.

The catalyst support metal fitting 10 is manufactured by knitting fine metal wires having excellent heat resistance, such as stainless steel, as will be described later. As shown in FIGS. 1 to 5, both end portions thereof have a substantially cylindrical shape. The holding portion 11 is formed. The peripheral wall of the holding portion 11 is corrugated in a slanted manner with respect to the axial direction.
The corrugation directions are formed so as to be inclined in opposite directions. The inner diameter R1 of the holding portion 11 is set to be slightly smaller than the outer diameter of the monolith carrier 3, and the outer diameter R2 of the holding portion 11 is set.
Is set to be slightly larger than the inner diameter of the casing 4.

The ends of the holding portions 11 facing each other are held by the holding portions 11.
A step portion 12 for dropping to the vicinity of the inner peripheral end of the catalyst is provided in series with the holding portion 11, and a connecting portion 13 for connecting the inner peripheral end portions of the adjacent step portions 12 is formed in the middle of the catalyst support metal fitting 10. ing. Deformation absorbing portions 14 connected to the step portion 12 are formed at both ends of the connecting portion 13, and a thin wire portion 15 formed of a plurality of curved metal thin wires connecting the deformation absorbing portions 14 is formed in the middle of the connecting portion 13. A pair of steps 12 and a connecting portion 13 are formed.
And form an annular groove 16 for mounting the sealing material. That is, the holding portion 11, the step portion 12, and the deformation absorbing portion 14 are formed of a knitted fabric in which metal thin wires are knitted, and the thin wire portion 15 is formed of a plurality of curved metal thin wires. However, the deformation absorbing portion 1
4 may be omitted, and the thin wire portion 15 may be directly connected to the inner peripheral end of the step portion 12. Further, as the thin line portion 15, metal thin wires having the same curvature are arranged in an orderly manner in the illustrated example, but it is also possible to arrange those having different curvatures at random.

The sealing material 5 is made by mixing vermiculite, hydrobiotite, or another vermiculite into an inorganic fiber material mainly composed of a ceramics fibrous material. When the sealing material 5 is heated by exhaust gas, the vermiculite is used. Are expanded and the sealing material 5 is configured to come into close contact with the casing 4 and the monolith carrier 3. However, it is also possible to use, as the sealing material 5, a core material composed of a thin metal wire or the like, to which an inorganic material is adhered. The seal / support metal fitting is composed of the catalyst support metal fitting 10 and the seal material 5.

Next, a method of manufacturing the catalyst support fitting 19 will be described. First, as shown in FIG. 6, a knitting machine (not shown) is used to knit a metal fine wire into a knitted knit to fabricate a tubular knitted object 20. At this time, the knitting is performed in a certain area facing each other in the circumferential direction. Then, the eyes are skipped and the knitted object 20 is produced in which a pair of braided portions 21 made of a knitted fabric extending in the axial direction and thin wire portions 22 made of a plurality of curved metal thin wires are alternately formed in the circumferential direction. . The knitted object 2 from the knitting machine
The feeding operation of 0 is performed by a pair of rollers 23 described below.

Next, while the produced cylindrical knitted object 20 is sandwiched between a pair of rollers 23 and fed, the knitted object 20 is folded into a flat plate shape with the central portion in the circumferential direction of the knitting portion 21 as a boundary to form a strip shape. A knit object 20A is produced. Since the tubular knitted object 20 is folded to produce the band-shaped knitted object 20A, the knitted object 20
The woven portion 21A of A and the thin line portion 22A are doubly overlapped.

Next, 2 formed on the band-shaped knitted object 20A
After sequentially corrugating the outer half portion of the braided portion 21A of the strip by press working, the knitted object 20A is cut at a constant length, and both longitudinal end portions are overlapped and joined together to form a cylinder. The catalyst-supporting metal fitting 10 is manufactured. In order to reduce the transportation cost, the production of the flat plate-shaped knitted object 20A is performed on the net manufacturing line, and the knitted object 20A is wound around a roll at the downstream end of the net manufacturing line.
The corrugation, cutting, and joining operations for 0A may be performed in the assembly line of the monolithic catalytic converter 1.

Next, the operation and effect of the catalyst support fitting 10 will be described. As shown in FIG. 3, the monolith-type catalytic converter 1 includes a catalyst support fitting 1 on the outer periphery of the monolith carrier 3.
0, and the annular groove 16 of the catalyst support fitting 10
With the sealing material 5 attached to the
Assembled and assembled. Assembled monolith carrier 3
Is held in the casing 4 via the catalyst support fitting 10, and the sealing material 5 is held in the gap 6 between the monolith carrier 3 and the casing 4.

The monolith carrier 3 is basically held on the casing 4 by a pair of holding portions 11. The holding portion 11 is composed of a braided portion 21A made of thin metal wire, and its peripheral wall is Because it is formed in a wavy shape,
It becomes elastic in the radial direction and the thickness direction, and is mounted in a stretched state between the outer peripheral surface of the monolith carrier 3 and the inner peripheral surface of the casing 4 to elastically hold the monolith carrier 3. Therefore, the holding portion 11 absorbs vibrations and the like when the engine is operating, and prevents damage to the monolith carrier 3.

The gap 6 between the casing 4 and the monolith carrier 3 is basically sealed with a sealing material 5. The sealing material 5 is a thin wire portion 15 composed of a plurality of curved metal thin wires. Since it is mounted in the annular groove 16 having a groove bottom surface, the outer peripheral surface of the seal material 5 is in direct contact with the inner surface of the casing 4, and the inner peripheral surface of the seal material 5 is
As shown in FIG. 4, it will be sufficiently adhered to the outer peripheral surface of the monolith carrier 3 through the gap between the metal thin wires of the connecting portion 13. Therefore, the sealing property of the gap 6 between the casing 4 and the monolith carrier 3 is improved, and the outflow of the unpurified gas is effectively prevented.

Further, the sealing material 5 is mounted between the pair of step portions 12 forming the side wall of the annular groove 16, and the connecting portion 13 connecting the step portions 12 allows the expansion and contraction in the axial direction to some extent. Since it is composed of a plurality of curved thin metal wires, the holding property of the sealing material 5 by the step portion 12 is enhanced.

Furthermore, since the step portion 12 and the deformation absorbing portion 14 are formed by the braided portion 21A, the load acting on the step portion 12 when the holding portion 11 is corrugated is determined by the step portion. The expansion and contraction of the deformation absorbing portion 12 and the deformation absorbing portion 14 effectively absorbs the deformation, thereby preventing breakage or damage of the thin metal wire in the step portion 12. Moreover, by providing the deformation absorbing portion 14, even when the processing position is slightly deviated in the axial direction during corrugation processing for the holding portion 11, breakage or damage of the thin metal wire in the step portion 12 can be prevented. Further, as the sealing material 5, the sealing material 5 made of an inorganic fiber material mainly composed of ceramic fibers is used, but since the step portion 12 made of the braided portion 21A prevents the sealing material 5 from being washed away, it changes with time. The deterioration of the sealing property due to the is effectively prevented. Moreover, since the inclination directions of the waves formed on both holding portions 11 are set to be opposite directions, even if the exhaust gas pressure acts on the monolith carrier 3, the catalyst support fitting 10 does not shift in the axial direction.

Incidentally, as in the catalyst support metal fitting 10A shown in FIG. 7, the three holding portions 11A and the two annular grooves 16A may be arranged alternately in the axial direction. In this case, a tubular knitted object in which four fine line portions and four knitted portions are alternately formed is produced, and the center portion in the width direction of the pair of opposed knitted portions of the knitted object is formed. At the boundary, the knitted object is folded in two to produce a band-shaped knitted object, and the band-shaped knitted object is subjected to processing such as corrugation, cutting, and joining to manufacture the catalyst support fitting 10A. However, it is also possible to form three or more annular grooves. In addition, in this embodiment, the holding portion 11, the step portion 12, and the deformation absorbing portion 14 are manufactured by knitting a metal thin wire, but a knitting method other than the knitting may be used, or a metal thin wire is woven. You may produce it.

[0030]

According to the catalyst support fitting of claim 1,
Since the monolith carrier is elastically held with respect to the casing via the holding portion, it is possible to effectively prevent damage to the monolith carrier due to engine vibration, running vibration, and the like. In addition, since the outer peripheral surface of the sealing material directly adheres to the inner surface of the casing, and the inner peripheral surface sufficiently adheres to the outer peripheral surface of the monolith carrier through the gap between the thin metal wires, the gap between the casing and the monolith carrier is It is possible to effectively prevent the unpurified exhaust gas from flowing out by improving the sealing performance of the. Further, since the plurality of thin metal wires forming the connecting portion are formed in a curved shape, expansion and contraction of the adjacent holding portion and the step portion in the axial direction is permitted to some extent, and the seal material in the axial direction of the adjacent step portion is allowed. Movement is effectively regulated.

Further, with a simple construction in which the step portion is formed by knitting or weaving, the load acting on the step portion when corrugating the holding portion is absorbed by expansion and contraction of the step portion, It is possible to prevent breakage and damage of the thin metal wire in the portion. Moreover, even if a sealing material made of an inorganic fiber material mainly composed of ceramics fibers is used as the sealing material, the stepped portion prevents the sealing material from flowing away,
It is possible to effectively prevent the deterioration of the sealing property due to aging.

According to the catalyst support metal fitting of the second aspect, it is possible to more effectively prevent breakage or damage of the thin metal wire when corrugating the holding portion. Claim 3
According to the seal / support metal fitting of the present invention, since the seal material mainly made of the ceramic fiber material is mounted in the annular groove of the catalyst support metal fitting of claim 1 or 2,
The same effect can be obtained.

According to the method of manufacturing a catalyst support fitting of claim 4, the cylindrical knitted objects that are continuously knitted are sequentially subjected to folding, corrugating, cutting, and joining processes. It becomes possible to continuously and easily manufacture the catalyst support fitting according to item 1.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a monolithic catalytic converter.

FIG. 2 is a perspective view of a catalyst support fitting.

FIG. 3 is a vertical cross-sectional view of a catalyst support metal fitting, a sealing material, and a monolith carrier.

4 is a sectional view taken along line IV-IV of FIG.

[Fig. 5] Exploded view of the catalyst support bracket

FIG. 6 is an explanatory view of a method for manufacturing a catalyst support fitting.

FIG. 7 is a perspective view of another structure of the catalyst support fitting.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Monolith type catalytic converter 2 Communication hole 3 Monolith carrier 4 Casing 5 Sealing material 6 Gap 10 Catalyst support metal fitting 11 Holding part 12 Step part 13 Connection part 14 Deformation absorption part 15 Thin line part 16 Annular groove 20 Braided object 21 Braided part 22 Fine wire 22 Part 23 Roller 20A Braided object 21A Braided part 22A Fine wire part 10A Catalyst support metal fitting 11A Holding part 16A Annular groove

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshitaka Abe 2-6-5 Hashirai, Toyonaka-shi, Osaka Japan Department of Industrial Products Co., Ltd.

Claims (4)

[Claims] 1. A thin metal wire which is mounted between a monolith carrier and a casing which covers the monolith carrier, elastically holds the monolith carrier with respect to the casing, and holds a sealing material for sealing a gap between the monolith carrier and the casing. A tubular catalyst support metal fitting, comprising a corrugated peripheral wall mounted in a stretched state between the outer peripheral surface of the monolith carrier and the inner peripheral surface of the casing, and provided at least one pair at regular intervals in the axial direction, A holding part made by knitting or weaving thin metal wires, and the ends of the holding parts facing each other are dropped to the vicinity of the inner peripheral end of the holding part. A holding part made by knitting or weaving thin metal wires is connected to the holding part. A step portion and a connecting portion that connects the inner peripheral end portions of the adjacent step portions with a plurality of curved thin metal wires connected to the step portion are provided. Ring groove Form catalyst support bracket. 2. The catalyst support metal fitting according to claim 1, wherein an annular deformation absorbing portion continuous with the step portion is formed by knitting or weaving metal fine wires at both ends of the connecting portion. 3. A catalyst support fitting according to claim 1 or 2, and a seal material mainly composed of a ceramic fiber material mounted in an annular groove of the catalyst support fitting, the outer peripheral surface of which is the inner peripheral surface of the casing. Also, a seal / support metal fitting, comprising: a seal member, the inner peripheral surface of which is attached to the outer peripheral surface of the monolith carrier so as to be in close contact with the outer peripheral surface of the monolith carrier through the gaps between the fine metal wires forming the connecting portion. 4. When knitting a thin metal wire into a tubular shape by knitting, knitting is performed by interrupting the knitting in a certain range facing each other in the circumferential direction, skipping the eyes, and knitting from a knitted fabric extending in the axial direction. A knitting process for producing a tubular knitted object in which a knitting part and a thin wire part composed of a plurality of curved metal thin wires are alternately formed in the circumferential direction, and Folding process to make a strip-shaped knitted object by folding it into a flat plate with the boundary as a boundary, and corrugation process for sequentially performing a corrugation process on a plurality of stitches formed on the strip-shaped knitted object. A method for manufacturing a catalyst-supporting metal fitting, comprising: a step of cutting a processed band-shaped knitted object at a constant length, and joining both longitudinal ends of the knitted object by superposing them.