JP2754017B2 - Metal supporting base for supporting exhaust gas purifying catalyst and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention generally carries an exhaust gas purifying catalyst interposed in an exhaust pipe as a means for purifying an exhaust gas of a vehicle. Of the metal carrier.

More specifically, a metal supporting matrix for supporting an exhaust gas purifying catalyst that has improved bonding strength between components of the metallic supporting matrix and can withstand separation between members due to thermal strain and the like, and It relates to a manufacturing method.

(Prior Art) Conventionally, a metallic supporting matrix for supporting this kind of exhaust gas purifying catalyst has a large supporting area per unit volume, that is, an exhaust gas and an exhaust gas purifying unit per unit volume. In order to increase the effective contact area with the catalyst for use as much as possible, and to reduce the weight of the metal supporting body as much as possible, a thin flat metal strip and a corrugated metal strip are used. Are laminated in a layered structure, or a structure in which both are collectively wound and laminated (hereinafter, these have a honeycomb-like structure and are referred to as a honeycomb core body).

For example, a flat strip made of a heat-resistant thin steel sheet having a thickness of 0.1 m / m or less and a corrugated strip formed by shaping the thin steel sheet into a corrugated shape are stacked so as to have contact portions with each other. This is wound in a spiral to form a honeycomb core body having a large number of mesh-shaped vent holes for exhaust gas passages in a certain direction. The wound and laminated honeycomb core bodies are housed in a cylindrical metal case having both ends opened and are joined to each other to have a vibration-proof structure. That is, a contact portion between the flat metal band member and the corrugated metal band member constituting the honeycomb core body and a contact portion between the honeycomb core body and the metal case are joined by welding or brazing.

Focusing on the joining of the abutting portion between the honeycomb core body and the metal case as these joining means, (i) as disclosed in JP-A-54-13462, JP-A-57-1585, etc. In addition, a method using electron beam welding, laser beam welding, arc welding, or the like. (Ii) As disclosed in JP-A-61-199574, after a honeycomb core body is loaded into a metal case, Various methods have been proposed, such as a method in which a brazing material is applied to the vicinity of the end by applying or spraying, and brazing is performed by heat treatment.

(Problems to be Solved by the Invention) However, the conventional bonding method described above has the following problems in manufacturing and quality.

For the joining means (i) such as electron beam welding and laser beam welding, a special and expensive device must be used.

In addition, in the joining means for applying and spraying the brazing material to the opening of the metal case after the honeycomb core body of (ii) is loaded in the metal case, the work of applying the brazing material is complicated, and It is difficult to uniformly and firmly join the outer peripheral surface of the honeycomb core body to the inner wall surface, and there is a problem particularly in the joining strength of the central portion.

Generally, this kind of metal carrier is used under a severe thermal environment, so that components and members are damaged,
Sufficient resistance to cracking and peeling is required. That is, -20 ° C to + 900 ° C found in automobile exhaust gas systems
Under the severe cooling and heat cycle, the components undergo strain (hereinafter, referred to as "thermal strain") due to a large difference in thermal expansion (volume expansion, linear expansion), and vibration of the vehicle body is also applied to the components, thereby causing a difference between the components. Separation (peeling), breakage of component members, cracks, etc. occur.

In particular, considering the corrosion resistance (oxidation resistance) of the metal case,
When different metal materials are used for the honeycomb core body in consideration of heat resistance (generally, an austenitic stainless steel is used for the former and a ferritic stainless steel is used for the latter). Detachment becomes brittle.

Therefore, in this type of metal supporting base, the metal case and the honeycomb core must be securely bonded with sufficient strength, but at present, there is no effective bonding method as described above.

An object of the present invention is to prevent the constituent members of a metal supporting base, that is, the constituent members of a cylindrical metal case and a honeycomb core body from being separated (peeled) for a long period of time, and exhibit a sufficient exhaust gas purification function. To provide a metal supporting base for supporting an exhaust gas purifying catalyst.

[Configuration of the invention]

(Means for Solving the Problems) To summarize the present invention, the present invention is directed to stacking a flat band material and a corrugated band material of a thin metal plate so as to abut each other, and forming a spiral or layered structure. A honeycomb supporting body having a large number of mesh-shaped ventilation holes in the axial direction manufactured by molding into a cylindrical shape, a metal supporting body for supporting an exhaust gas purifying catalyst formed by being fixed in a cylindrical metal case. , The cylindrical metal case,
Metals for supporting an exhaust gas purifying catalyst, characterized in that they are formed with fine recesses that promote the permeability of the molten brazing material over the entire inner wall surface including the inner wall surfaces at both end portions thereof. It relates to a supporting base.

In addition, the present invention provides a method for producing the above-described metal supporting base, that is, (i). As the cylindrical metal case, a metal case in which a fine concave portion is formed to promote the permeability of the molten brazing material over the entire inner wall surface including the inner wall surfaces at both ends is used, and the fine concave portion is filled or filled with the brazing material. Without loading the honeycomb core body into the metal case, (ii). Next, when the fine recess is not filled with the brazing material in the step (i), the brazing material is supplied to a portion near the opening end of the metal case, and a heat treatment is performed at a temperature equal to or higher than the melting temperature of the brazing material. And a process for producing the above-mentioned metal carrier.

 Hereinafter, the configuration of the present invention will be described in detail.

The present invention is characterized in that the joining strength between the honeycomb core body, which is a constituent member of the metal supporting base, and the cylindrical metal case is improved as described above. In particular, the present invention has sufficient bonding strength not only near the opening of the inner wall surface of the cylindrical metal case but also at the center portion and the vicinity thereof, that is, over the entire bonding surface with the outer peripheral surface of the honeycomb core body. It is characterized in that

The means for improving the bonding strength between the honeycomb core body and the cylindrical metal case will be described with reference to the drawings.

FIGS. 1 and 2 are perspective views of a metal supporting base (1, 1 ') for supporting the exhaust gas purifying catalyst of the present invention. The honeycomb core body (2) shown in FIG. 1 is obtained by winding a flat metal strip (3) and a corrugated metal strip (4) together in a spiral shape, and the honeycomb core body shown in FIG. (2 ') is obtained by laminating a flat metal strip (3') and a corrugated metal strip (4 ') in a hierarchical manner. The honeycomb core body (2,
2 ') has a large number of mesh-shaped vent holes (5, 5') in the axial direction, and as shown in FIGS. 1 and 2, a cylindrical metal case (6, 6 '). The honeycomb core body and the metal case are firmly fixed in a manner described later.

In the present invention, as a means for improving the joining strength between the honeycomb core body (2, 2 ') and the tubular metal case (6, 6'), the honeycomb core body (2, 2 ') is joined to the entire inner wall surface of the tubular metal case. When the brazing material is applied and melted, fine recesses (7) are formed to promote the permeability of the brazing material.

The fine recesses (7) formed on the entire inner wall surface of the metal case are formed in various modes as shown in FIGS. These fine recesses are rolled, ground,
It is formed into a linear shape, a curved shape, a point shape (a satin shape), or a combination thereof by a process such as pressing and honing. It goes without saying that the above-mentioned curves include a wavy curve.

FIG. 3 is a longitudinal sectional view of the metal case (6), and the fine concave portion (7) extends in parallel with the axial center direction over the entire inner wall surface between the openings at both ends of the metal case (6). And are formed linearly at desired intervals.

The fine concave portion (7) in FIG. 4 is formed in a straight line parallel to the axial direction of the metal case (6), which is a modification of the one in FIG.

The fine concave portion (7) in FIG. 5 is a modification of the one in FIG. 4, and has a curved shape (corrugated shape) compared to the linear shape in FIG.
Formed.

The fine recesses (7) in FIG. 6 are formed linearly at desired angles and at desired intervals with respect to the axial direction of the metal case (6) so as to cross each other.

The fine concave portion (7) in FIG. 7 is formed in a curved shape in comparison with the linear shape in FIG.

The fine recesses (7) in FIGS. 8 and 9 are formed in a direction perpendicular to the axial direction of the metal case (6) in a straight line or a curved line at a desired interval.

The fine concave portion (7) in FIG. 10 is formed in a dot-like (satin-like) shape on the entire inner wall surface of the metal case (6).

In the present invention, the fine concave portion (7) is not limited to the above-described example, and may be a combination of a linear shape and a curved shape, a combination of a linear shape and a matte shape,
The formation method may be any appropriate one.

In the present invention, the metal case (6) and the honeycomb core body () are formed from the open end of the metal case (6) at the time of brazing by the fine recess (7) formed on the entire inner wall surface of the metal case (6). The molten brazing material infiltrating from between 2) is uniformly diffused to the central portion of the metal case (6) and the entire outermost periphery of the honeycomb core body by capillary action,
Thereby, reliable and strong joining between the metal case (6) and the honeycomb core body (2) can be achieved.

In order to manufacture a metal supporting base for supporting the exhaust gas purifying catalyst of the present invention, as described above, the fine concave portion (7) formed on the entire inner wall surface of the metal case (6) includes:
The honeycomb core body (2) is press-fitted with or without the brazing filler metal, and then the brazing filler metal is supplied or not supplied by applying, spraying, or the like to a portion near the opening end of the metal case. The heat treatment may be performed at a temperature higher than the melting temperature of the brazing material. The molten brazing material permeates uniformly and over the entire area between the metal case (6) and the honeycomb core body (2) due to the capillary phenomenon in the minute concave portion (7), whereby the joining of both is ensured. It will be.

In the present invention, the abutting portion (the flat metal strip and the corrugated sheet) of the flat metal strip (3, 3 ') and the corrugated metal strip (4, 4') constituting the honeycomb core body (2) are provided. The contact of the plate-shaped metal strip with the peaks and valleys) may be performed by an ordinary method. The honeycomb core body (2) is replaced with a metal case (6).
In the method of manufacturing a metal supporting body by applying a brazing filler metal to a portion near the opening end of the metal case after being loaded into the metal case, a contact portion between the flat metal band material and the corrugated metal band material is used. Since the joining is performed simultaneously with the joining between the outer peripheral surface of the honeycomb core body (2) and the inner wall surface of the metal case, it is productive.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

(I) Manufacture of honeycomb core body The flat metal strip was a heat-resistant thin steel strip made of ferrite stainless steel of 20% Cr and 5% Al and having a thickness of 0.04 m / m and a width of 74.5 m / m. Next, the band material was processed into a corrugated metal band material having a pitch width of 2.5 m / m in the longitudinal direction by passing the band material between forming gears.

Next, the flat metal strip and the corrugated metal strip are overlapped with each other so as to have an abutting portion. 70m / m
A honeycomb core body having a large number of mesh-shaped vent holes in the axial direction was manufactured.

(Ii) Production of metal case Austenitic stainless steel (SUS304) flat plate,
A fine concave groove with a width of 0.03 mm and a depth of 0.02 mm was formed by rolling with a roll, and from this a cylindrical metal case with an inner diameter of 70 m / m, a wall thickness of 1.2 m / m, and a length of 75 m / m was manufactured. . The fine recesses were formed on the inner wall surface of the metal case as shown in FIG.

(Iii) Manufacture of a metal supporting base A paste-like brazing material (nickel-based) was filled in minute concave portions formed on the inner wall surface of the metal case. Next, the honeycomb core body was press-fitted and heat-treated at 1100 ° C. in vacuum, and the metal case and the honeycomb core body were brazed.

As a result, it was possible to manufacture a metal supporting base in which the metal case and the honeycomb core body were not separated from each other for a long period of time.

〔The invention's effect〕

The present invention is directed to stacking a flat band material and a corrugated band material of a thin metal plate so as to abut each other, forming a spiral or hierarchical shape, and forming a large number of mesh-shaped vent holes in the axial direction. A honeycomb core body having a metal core for supporting an exhaust gas purifying catalyst, wherein both are fixed by press-fitting a brazing material into a cylindrical metal case, and the cylindrical metal case, The use of a material having fine recesses formed on the entire wall surface to promote the penetration of the molten brazing material provides the following excellent effects.

(I) When joining the metal case and the honeycomb core body, the molten brazing material uniformly spreads over the entire outer peripheral surface of the honeycomb core body due to the capillary phenomenon in the fine concave portions, so that the bonding strength between the metal case and the honeycomb core body is increased. Can be significantly improved.

(Ii) In particular, since the joining strength at the central portion of the metal case and the vicinity thereof can be significantly improved as compared with the conventional one, a metal supporting base having excellent vibration resistance can be obtained.

(Iii) It is easy to control the amount of brazing material used.

[Brief description of the drawings]

FIG. 1 is a perspective view of a wound metal supporting base for supporting the exhaust gas purifying catalyst of the present invention, and FIG. 2 is a perspective view of a hierarchical metal supporting base of the present invention. FIG. 3 is a longitudinal sectional view of a metal case in which fine concave portions are formed linearly in parallel with the axial direction of the metal case by the first method of the present invention. FIG. 4 is a longitudinal sectional view of a metal case in which fine concave portions are formed linearly by the second method of the present invention. FIG. 5 is a longitudinal sectional view of a metal case in which fine concave portions are formed in a curved shape (corrugated shape) by the third method of the present invention. FIG. 6 is a longitudinal sectional view of a metal case in which fine linear recesses are formed so as to cross each other by the fourth method of the present invention. FIG. 7 is a longitudinal sectional view of a metal case in which curved fine concave portions are formed so as to cross each other by the fifth method of the present invention. FIG. 8 is a longitudinal sectional view of a metal case in which fine concave portions are linearly formed in a direction perpendicular to the axial direction of the metal case by the sixth method of the present invention. FIG. 9 is a longitudinal sectional view of a metal case in which fine concave portions are formed in a curved shape (corrugated shape) in a direction perpendicular to the axial direction of the metal case according to the seventh method of the present invention. FIG. 10 is a longitudinal sectional view of a metal case in which fine concave portions are formed in a dot shape (matte shape) by the eighth method of the present invention. 1,1 ': Metal carrier 2,2': Honeycomb core 3,3 ': Flat metal strip 4,4': Corrugated metal strip 5,5 ': Mesh Ventilation passage 6,6 '... Metal case 7 ... Fine recess

Claims (7)

(57) [Claims] 1. A large number of meshes in the axial direction manufactured by laminating a flat band material and a corrugated band material of a thin metal plate so as to be in contact with each other and forming them in a spiral or hierarchical shape. A honeycomb core body having an air hole passage, in a metal supporting base for supporting an exhaust gas purifying catalyst fixed in a cylindrical metal case, wherein the cylindrical metal case has inner wall surfaces at both ends thereof. A metal supporting base for supporting an exhaust gas purifying catalyst, comprising a fine concave portion formed to promote permeability of a molten brazing material over the entire inner wall surface including the same. 2. The metal supporting base according to claim 1, wherein the fine concave portion is formed in a straight or curved shape on the entire inner wall surface communicating with both open ends of the metal case. 3. A metal product according to claim 2, wherein said fine concave portion is formed in a straight line or a curved line at a desired interval on the entire inner wall surface of the metal case in parallel with the axial direction. Carrying matrix. 4. The fine concave portion is formed in a straight or curved shape so as to cross each other at a desired angle with respect to the axial direction and at a desired interval on the entire inner wall surface of the metal case. The metallic carrier according to claim 2, which is a metal. 5. The metal carrier according to claim 2, wherein the fine concave portion is formed in a straight line or a curved line in a direction perpendicular to the axial direction on the entire inner wall surface of the metal case. Mother. 6. The metal supporting base according to claim 1, wherein the fine concave portion is formed in a dot shape (pear-skin shape) on the entire inner wall surface of the metal case. 7. A large number of meshes in the axial direction manufactured by laminating a flat band member and a corrugated band member of a thin metal plate so as to be in contact with each other and forming them in a spiral or hierarchical shape. In a method of manufacturing a metal supporting matrix for loading a honeycomb core body having an air hole passage in a cylindrical metal case and fixing the honeycomb core body to the metal case to support an exhaust gas purification catalyst, (I). As the cylindrical metal case, a metal case in which a fine concave portion is formed to promote the permeability of the molten brazing material over the entire inner wall surface including the inner wall surfaces at both ends is used, and the fine concave portion is filled or filled with the brazing material. Without loading the honeycomb core body into the metal case, (ii). Next, when the fine recess is not filled with the brazing material in the step (i), the brazing material is supplied to a portion near the opening end of the metal case, and a heat treatment is performed at a temperature equal to or higher than the melting temperature of the brazing material. A method for producing a metal carrier for supporting an exhaust gas purifying catalyst, comprising the steps of: