JPH06327982A - Honeycomb body - Google Patents

Abstract

PURPOSE:To provide a highly durable honeycomb body by eliminating the factor to decrease the durability induced from the end face of the honeycomb body by a special grazing means. CONSTITUTION:The flat strip 1 and corrugated strip 2 made from a thin metallic sheet are laminated on one another to produce a honeycomb body, the desired abutting parts of the flat strip 1 and corrugated strip 2 are grazed to obtain the honeycomb body H for carrying an exhaust gas cleaning catalyst. In this case, at least one end face of the honeycomb body H is constituted of a thing having a non-glazed part of a desired width from the end face.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to an exhaust gas purifying apparatus which is used as an exhaust gas purifying means for an automobile by being inserted in the middle of an exhaust system, and more particularly to an exhaust gas purifying catalyst which is a main component thereof. The present invention relates to a metal honeycomb body for carrying (hereinafter, simply referred to as a honeycomb body). More specifically, the present invention relates to a honeycomb body excellent in durability manufactured by applying a special brazing joining means.

[0002]

2. Description of the Related Art Conventionally, a metallic carrier for supporting a catalyst for purifying exhaust gas of this kind (for example, a catalyst using Pt, Rh, Pd, etc.) has a large amount of catalyst supported per unit volume. (To maximize the effective contact area between the exhaust gas and the purifying catalyst per unit volume), to reduce the back pressure (exhaust resistance), and to reduce the weight of the metal-supported matrix as much as possible. , Etc., a well-known honeycomb body is a heat-resistant thin-walled metal flat plate band member and corrugated plate band member that are stacked so as to contact each other. . It should be noted that various honeycomb bodies such as a laminated type, a wound type, a radial type, an S-shaped type, a barbed type, or an X-wrapped type can be obtained depending on the method of forming the honeycomb body.

The above-mentioned honeycomb body is, for example, as shown in FIG. 1, a flat strip (1) made of a heat-resistant thin steel plate of 0.1 mm or less (preferably 50 μm or less) and a corrugated thin steel plate. The formed corrugated strip material (2) is stacked so as to have mutual abutting parts, which are wound together in a spiral to form a large number of mesh-like ventilation holes for the exhaust gas passage in the axial direction. Winding type honeycomb body (H) having channels (3)
It is said that And, this wound and laminated honeycomb body is
Cylindrical metal case (4) with both ends open as required
The metal carrier (MS, metal support) having a vibration-proof structure is housed in and bonded to each other.

As is well known, the metal carrier (MS), which is a main component of this type of exhaust gas purifying apparatus, is used because it is used under severe thermal environmental conditions of the exhaust gas system. The honeycomb body, which is an important component, has high temperature corrosion resistance (gas corrosion resistance, corrosion resistance in exhaust gas system around 1000 ° C), cold and heat resistance (durability in cycle of stopping and starting internal combustion engine), It is preferable that the foil material is made of heat-resistant steel having excellent physical properties such as high-temperature oxidative property (durability against abnormal oxidation under high temperature). Fe-Cr-Al system (20Cr-
Heat-resistant steel such as 5Al series is rolled into foil with a thickness of several tens of μm. Also, in order to improve the high temperature oxidation resistance of the heat resistant steel, a small amount of rare earth element component (REM) is used.
The one with added is also used.

In addition, since the metal carrier (MS) is used under severe vibration, the honeycomb member, which is a main constituent of the metal carrier, is one of the abutting portions of the strip members constituting the honeycomb member. A part or the whole is fixed by welding, a brazing material, etc., and has a vibration resistant structure.

Many techniques have been proposed as the above-mentioned techniques for welding the honeycomb body and fixing the brazing material. For example, as joining means by welding, Japanese Patent Laid-Open No. 54-13
No. 462, Japanese Utility Model Laid-Open No. 62-156112, Japanese Patent Laid-Open No. 63-
Laser beam welding, electron beam welding, plasma beam welding and the like have been proposed in No. 36843. However, in these various welding means, there are drawbacks such as use of expensive welding equipment, complexity of welding work, and low productivity,
Further, as described above, since the constituent parts of the honeycomb body are heat resistant, there is a drawback that a high temperature is applied to the welded part and the welded part becomes brittle in the cast structure.

On the other hand, in the honeycomb body manufacturing technique, the fixing means using the brazing material is excellent because it does not have the above-mentioned drawbacks due to welding. As a joining means using this kind of brazing filler metal, there are Japanese Patent Laid-Open No. 56-4373 and Japanese Patent Publication No. 63-4.
No. 4466, etc., in which the brazing material is applied to a part or all of the abutting portions of the band materials forming the honeycomb body while considering the deterioration of the base material due to the brazing material, the relaxation of the thermal stress of the honeycomb body, and the absorption. Is proposed.

As described above, in the honeycomb body, which is a main constituent element of the metal carrier (MS), efforts are made from the viewpoint of material and vibration-proof structure in order to improve and improve durability (vibration resistance, heat resistance strength, etc.). Has been paid, but not enough. Particularly, in the honeycomb body, under the severe thermal environment conditions described above, an extremely large thermal deformation force is applied to each part of the honeycomb body (both in the radial direction and the axial direction of the honeycomb body), and vibration conditions are added to this. , Its durability improvement is a big problem.

[0009]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention is intended to improve the durability of the honeycomb body as described above. In particular, the inventors of the present invention have observed that the end face portion of the honeycomb body is a flat plate-shaped strip material which is a constituent member of the honeycomb body and / or
Or, attention is paid to the damage phenomenon of the corrugated strip.

No improvement measures have been taken in the prior art for the breakage of the strip material observed at the end face portion of the honeycomb body. In this respect, the present inventors have made a few suggestions earlier. For example, (a) the end face portion of the honeycomb body is configured not to be flush with both the flat plate-shaped band member and the corrugated plate-shaped band member, but one of the band members is projected from the other (Patent application (Heisei 4-131365), or (b) The main cause of cracks and growth of the flat plate-shaped strip material and / or corrugated plate-shaped strip material observed in the end face portion of the honeycomb body is derived from the microstructure of the end portion of the strip material. In order to solve this problem, a proposal was made such that the edge portion of the strip material was subjected to energy processing so as not to have an irregular structure (Japanese Patent Application No. 4-273542).

The present invention is intended to solve the above-described problem of measures against damage to the strip material at the end face portion of the honeycomb body by improving the brazing means. The present invention has the above-mentioned drawbacks in the case where a contact portion between the flat plate-shaped strip material and the corrugated plate-shaped strip material forming the honeycomb body is provided in the end face portion of the honeycomb body with no brazing (non-brazing joint). The present invention provides a honeycomb body having excellent durability, which is based on the finding that is effectively eliminated.

[0012]

The present invention will be summarized as follows.
The present invention is manufactured by stacking flat-plate strips and corrugated strips made of thin metal plates so that they are in contact with each other, and the flat strips and corrugated strips are brought into contact with each other as desired. In a honeycomb body for carrying an exhaust gas purifying catalyst whose parts are brazed, the honeycomb body is configured to have at least one end face part having a non-brazing joint part of a desired width from the end face. The present invention relates to a characteristic honeycomb body.

The technical construction and embodiments of the present invention will be described in detail below with reference to the drawings. Needless to say, the present invention is not limited to the illustrated one.
As described above, the present invention is the damage of the flat strip material and / or the strip material on the corrugated plate observed in the end face portion of the honeycomb body,
It aims to improve the durability of the honeycomb body by paying attention to cracks and their growth. The present inventors believe that the conventional brazing means is the cause of the decrease in durability of the honeycomb body. That is, the contact portion between the flat plate-shaped band member and the corrugated plate upper band member, which are the constituent members of the honeycomb body, in particular, the contact portion of the end face portion of the honeycomb body and the vicinity thereof is all in the conventional brazing method. It is carried out in the form of brazing.

In the above-mentioned conventional brazing method, the durability of the end face portion of the honeycomb body and the portion in the vicinity thereof is reduced as follows. (I) At the time of brazing, the metal forming of the brazing material causes thermal diffusion in the band material to form an intermetallic compound, which causes embrittlement, and the coefficient of thermal expansion partially changes. produce. (Ii) During the use of the honeycomb body, a large thermal deformation force is concentrated and piled up on the end portion of the honeycomb body, so that the band material at the end portion is damaged,
The crack and its growth are increased. (Iii) Further, during use of the honeycomb body, violent vibration is applied, so that the growth of the breakage and cracks is accelerated.

From the above, the durability of the honeycomb body,
In particular, in order to improve the durability of the end face portion, it is necessary to improve the brazing method of the contact portion between the flat band member and the upper corrugated plate member forming the honeycomb body in the vicinity of the end face portion. Therefore, the present invention employs, as the brazing means applied to the honeycomb body, a technical configuration in which at least one end face portion of the honeycomb body is provided with a non-brazing joint portion having a desired width from the end portion.

1 to 3 are explanatory views of a wound type honeycomb body manufactured by applying the brazing method of the present invention. FIG. 1 is a perspective view of a part of the honeycomb body of the present invention seen through. FIG. 2 is a sectional view in which a part of the honeycomb body of FIG. 1 is omitted. FIG. 3 is an enlarged perspective view of an end surface portion of the honeycomb body. As shown in the figure, a wound type honeycomb body (H) consisting of a flat strip (1) and a corrugated strip (2) has a non-wax-bonded width (W _N ) on both end faces (i). Section (NBA) is provided, (ii) the non-brazing joint section (NB)
Width adjacent to A) (W _B) of filtrate will joints provided (BA), is intended to be manufactured in a manner that.

In the present invention, the non-brazing joint (NB
The width (W _N ) of A) is set to a desired width,
The width is preferably at least 1 mm or more. Also,
If one pays attention to the pitch width of the wave of the corrugated strip, at least 1
It is preferable to have a width corresponding to the pitch. In the present invention, the width (W _B ) of the brazing portion (BA) may be appropriately set in consideration of absorption and relaxation characteristics of the thermal deformation force in the radial direction and / or the axial direction of the honeycomb body. Note that FIG.
In the embodiment shown in FIGS. 3A to 3C, the brazing joints (BA) are provided in the vicinity of both ends, but the brazing joints (B) are not provided.
It goes without saying that A) may be provided only in the vicinity of one end face portion. In addition, it goes without saying that the brazing joint (BA) may be provided in various conventionally known modes as long as the condition that the non-brazing joint (NBA) having the predetermined width (W _N ) is provided is maintained. There is no such thing.

In the present invention, any brazing material known in the art may be adopted without any particular restriction. For example, a brazing material containing Ni, Al, Cr, or Fe or a combination of these components as a main component may be used. Moreover, Y, La, and
It is also possible to use a brazing material having Ce, Ti, Zr or the like added thereto to improve high temperature oxidation resistance. Further, Si or the like may be added to change the melting temperature of the brazing material. In the present invention, when a band material (1, 2) constituting the honeycomb body is added with an Al component, if a Ni-based brazing material is used, Al and Ni in the base material are easily alloyed. The amount of Al ₂ O ₃ that causes the reaction and imparts the high temperature oxidation resistance is reduced. From this point of view, a brazing material containing no Ni, for example, an Al-based brazing material is preferable. Such a brazing material can perform brazing with sufficient strength at a low temperature and improve the high temperature oxidation resistance of the honeycomb body. I can. As described above, it is important in the present invention that no brazing material is present in the non-brazing joint, and the abutting portions of the strip materials (1, 2) of the non-brazing joint are diffusion-bonded by thermal diffusion. It doesn't matter.

Hereinafter, in the end face portion of the honeycomb body (H), a non-brazing joint portion (NBA) having the above-mentioned predetermined width (W _N ) is formed.
And attention to be described in a predetermined width (W _B) of filtrate will flat strip for providing joint a (BA) (1). In the present invention, the mode in which the non-brazing joint (NBA) is provided is not limited to the flat strip (1), but the corrugated strip (2).
It goes without saying that it may be applied to.
Furthermore, in the present invention is that it goes without saying that no particular limitation to the manner of providing a predetermined width (W _B) of filtrate will junction (BA). For example, a method of applying a brazing filler metal only to the corrugated top of the corrugated strip (2) and brazing it is adopted.

FIG. 4 shows a non-brazing joint (NBA) having a predetermined width (W _N ) and a brazing joint ( _{B B} ) having a predetermined width (W _B ).
It is a figure explaining the 1st embodiment applied to the flat strip (1) for providing A). That is, the aspect of FIG. 4 is a flat strip (1) (a part thereof is omitted and shown).
A predetermined width by the non-braze joint from the end portion (NBA) width to form a (W _N) powder is sprayed in a subsequent step, leaving a shaped brazing material for the binder (adhesive) (W _B) To form the binder coating part (5). A high-temperature brazing material such as a Ni-based material is sprinkled on the flat strip (1) and is wound together with the corrugated strip (2) to form a wound honeycomb body (H). It is heat-treated in a furnace or the like and brazed. It goes without saying that, at this time, the binder coating portion (5) becomes the brazing joint portion (BA). In the present invention, it goes without saying that, as a modified example of the above-mentioned embodiment, the binder film portion (5) may be made of a brazing material paste obtained by mixing a binder and a powdery brazing material.

FIG. 5 shows a non-brazing joint (NBA) having a predetermined width (W _N ) and a brazing joint ( _B ) having a predetermined width (W _B ).
It is a figure explaining the 2nd embodiment applied to the flat strip (1) for providing A). The aspect of FIG. 5 is different from that of FIG. 4 in that a brazing material foil portion (6) is provided instead of the binder coating portion (5). in this case,
It goes without saying that the step of applying the brazing material in the subsequent step is omitted.

FIG. 6 shows a non-brazing joint (NBA) having a predetermined width (W _N ) and a brazing joint ( _B ) having a predetermined width (W _B ).
It is a figure explaining the 3rd embodiment applied to the flat strip (1) for providing A). The embodiment of FIG. 6 is such that an aqueous dispersion of a powder brazing filler metal in a subsequent step is formed in a width (W _N ) portion for forming a non-brazing joint portion (NBA) from an end portion of the flat strip (1). The point is that the water-repellent coating (7) is provided so that the brazing material does not adhere during the immersion treatment in the bath.
A ceramic paint or the like may be used as the anti-adhesion agent for the brazing material.

[0023]

EFFECTS OF THE INVENTION The flat metal strip and the corrugated metal strip of the present invention are manufactured by stacking them so that they are in contact with each other, and the desired contact portions of both strips are formed. The joined honeycomb body has a non-brazing joint portion having a desired width at least on one end face portion and a portion in the vicinity thereof. In the non-brazing joint portion of the present invention, since the thermal diffusion of the brazing material component and the formation of the intermetallic compound of the component and the band material are prevented, embrittlement of the band material at the site is prevented, It is possible to effectively absorb and alleviate the thermal deformation force that is concentrated and accumulated in the end face portion (non-brazing joint portion) during the use of the honeycomb body. Therefore, the present invention provides a honeycomb body having excellent durability.

[Brief description of drawings]

FIG. 1 is a perspective view in which a part of a metal carrier (MS) using a honeycomb body (H) of the present invention is seen through.

FIG. 2 is a cross-sectional view in which a part of the metal carrier (MS) of FIG. 1 is omitted.

FIG. 3 is a partially enlarged perspective view of the honeycomb body (H) of FIG.

FIG. 4 is a diagram for explaining the configuration of the flat strip (1) of the first embodiment.

FIG. 5 is a diagram for explaining the configuration of the flat strip (1) of the second embodiment.

FIG. 6 is a view for explaining the configuration of the flat strip (1) of the third embodiment.

[Explanation of symbols]

 MS …… Metal carrier H ………… Honeycomb body 1 ………… Flat strip material 2 ………… Corrugated strip material 3 ………… Reticulated vent holes (cells) 4 ………… Casing 5 ………… Binder Coating part 6 ………… Brazil foil part 7 ………… Water-repellent coating part

Claims (6)

[Claims] 1. A flat metal strip made of a thin metal plate and a corrugated metal strip are piled up so as to be in contact with each other, and the flat metal strip and the corrugated metal strip are bonded to each other as desired. In a honeycomb body for carrying an exhaust gas purifying catalyst in which a contact portion is brazed, the honeycomb body is configured to have a non-brazing joint portion having a desired width from at least one end surface portion from the end surface. A honeycomb body characterized by the above. 2. The honeycomb body according to claim 1, wherein the width of the non-brazing joint portion is within 5 mm. 3. The honeycomb body according to claim 1, wherein the width of the non-brazing joint portion has one pitch width of the corrugated plate material. 4. The honeycomb body according to claim 1, which has a brazing joint having a desired width adjacent to the non-brazing joint. 5. The honeycomb body according to claim 4, wherein the width of the brazing joint is within 50 mm from the end face of the honeycomb body. 6. The honeycomb body according to claim 5, wherein the width of the brazing joint is within 10 mm.