JPH07171406A - Metallic carrier - Google Patents

Abstract

PURPOSE:To obtain a metallic carrier having a structure formed by arranging metallic wires in metallic casing and excellent in characteristics as well is in profitableness in place of a metallic carrier based on a metallic honeycomb body using one or both of conventional expensive flat and corrugated sheetlike strip materials (foil materials). CONSTITUTION:This metallic carrier for carrying a catalyst for purification of exhaust gas consists of metallic casing made of heat resistant steel and metallic wires. The casing has hole forming parts O1-On (n>=2) parallel to each other along the periphery of the wall at desired intervals d1-dn-1 (n>=2) in the axial direction. A desired number of holes have been formed in the hole forming parts at desired pitches (p) and the wires have been fixed in the holes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a metal carrier used for supporting an exhaust gas purifying catalyst used in an automobile exhaust gas purifying apparatus. More specifically, the present invention replaces the constituent member of the metal carrier made of metal with a conventional expensive heat-resistant steel flat plate-shaped strip material (foil material) and / or corrugated plate-shaped strip material (foil material). The present invention relates to an economical metal carrier having excellent properties such as durability, which is characterized by comprising a metal casing and a metal wire arranged in the metal casing.

[0002]

2. Description of the Related Art Conventionally, as a catalyst carrier for an exhaust gas purifying apparatus of this type, a ceramic monolith type (ceramic monolith) using a ceramic material such as cordierite and a metal monolith type are used. The thing of (metal monolith) is known. Particularly in recent years, metal monoliths have been actively researched and developed in order to improve the defects of ceramic monoliths, that is, from the viewpoints of mechanical strength, durability, ventilation resistance, purification efficiency (miniaturization of the device), and the like.

Typical examples of this type of conventional metal catalyst carrier (metal carrier) (MS ', metal support) are shown in FIGS. This type of metal carrier generally comprises a flat strip (1) made of a thin steel plate excellent in high temperature oxidation resistance and heat resistance and a corrugated strip (2) formed by corrugating the thin steel plate. Stack so that they have abutting parts,
A metal honeycomb having a large number of mesh-like vent holes (cells) (3) for the exhaust gas passage in the axial direction, which are manufactured by stacking them in a spiral shape or stacking them in a layered manner. The structure (H) (metal honeycomb body) and the cylindrical metal case (4) with both ends opened for filling and fixing the metal honeycomb body. 5 shows a wound type metal honeycomb body (H), and FIG. 6 shows a laminated type metal honeycomb body (H).

The metal honeycomb body and the metal case forming the metal carrier are heated by the high temperature of the exhaust gas itself and an exothermic reaction between the exhaust gas and the purification catalyst (catalyst such as Pt, Pd, Rh). It is firmly fixed by brazing or welding so as to be able to withstand expansion and thermal stress, and also to be able to withstand vibration and the like when the vehicle is running. Needless to say, the abutting portions of the flat strip material and the corrugated strip material that form the metal honeycomb body are fixed by various methods.

In the above-mentioned conventional metal honeycomb body, the flat strip (1) and the corrugated strip (2) which are the constituent members thereof are, for example, chromium steel (chromium 13 to 25%),
A band material (foil material) with a thickness of 0.1 mm or less such as heat-resistant stainless steel such as Fe-Cr 20% -Al5% or stainless steel to which rare earth is added to improve the high temperature oxidation resistance is used. To be done. In addition, the stainless steel containing Al in each strip has improved high-temperature oxidation resistance, and α-Al ₂ O ₃ of various shapes such as whiskers or mushrooms is deposited on the surface of the strip by heat treatment, This is a very preferable material because it firmly fixes the wash coat for supporting the exhaust gas purifying catalyst.

However, the flat strip material (1) and the corrugated strip material (2) constituting the above-mentioned metal honeycomb body (H) are the material itself or a foil material (thickness) applied to this kind of use. (0.04 mm to 0.1 mm) is extremely expensive as it requires a rolling cost, which greatly reduces the price competitiveness of the metal honeycomb body with respect to the ceramic honeycomb body. Further, as described above, when brazing the constituent members in the manufacture of the metal honeycomb body, an expensive high-temperature brazing material such as Ni-based material is used, and this is also costly.

[0007]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention relates to a metal carrier using the conventional high-priced strip material (foil material) described above, in relation to the configuration of a tubular metal casing. By replacing the (foil material) with a wire material made of heat-resistant steel, it is intended to bring out the cost merit and to provide a metal carrier having superior performance to that using the conventional strip material (foil material). is there.

[0008]

The present invention will be summarized as follows.
The present invention provides a metal carrier for carrying an exhaust gas purifying catalyst comprising a metal casing made of heat-resistant steel and a metal wire. (I) The metal casing has a desired spacing (d ₁ , d ₂ , ………… d _n-1 ; n ≧ 2)
, And hole forming parts (O ₁ , O ₂ , ..., O _n ; n ≧ 2) which are parallel to each other along the peripheral edge of the wall part, and have a desired pitch ( p), a desired number of holes are formed, and (ii) the metal wire has the hole forming portions (O ₁ , O ₂ , ... ......).
The present invention relates to a metal carrier characterized by being arranged in a hole of O _n ; n ≧ 2).

The technical construction and embodiments of the present invention will be described below with reference to the drawings. Needless to say, the present invention is not limited to the illustrated one.

FIG. 1 is a perspective view in which a part of the metal carrier (MS) of the present invention is seen through and a part thereof is omitted. As shown in the figure, the metal carrier (MS) of the present invention comprises a metal casing (C) made of heat-resistant steel and the metal casing (C).
It is composed of two components, a metal wire (W) made of heat-resisting steel, which is arranged in the.

[0011] Metal casing of the first element constituting the metallic support (MS) (C) of the present invention, as illustrated, the desired distance to the wall portion of the-axis (d _1, d _2, .........
d _n-1 ; n ≧ 2) and the hole forming portions that are parallel to each other, for example, n rows of hole forming portions (O ₁ , O ₂ , ... ...... O _n ;
n ≧ 2), and each of the hole forming portions (O ₁ , O ₂ ,
........ O _n ; n ≧ 2), a desired number of hole portions are formed in each hole forming portion, and more specifically, a desired pitch (p) is formed in the hole forming portions (O ₁ ) in the first row, for example. , And has a desired number of holes, for example, m holes (O ₁₁ , O ₁₂ , ..., O _1m ; m ≧ 2). Needless to say, the pitch (p) does not necessarily have to be equal intervals.

[0012] Metal wires of the second element constituting the metallic support (MS) of the present invention (W), as illustrated, & each hole forming portions _{(O 1, O 2, .........} O n; n ≧ 2)
In each row, for example, in the hole forming portion (O ₁ ) in the first row, m holes (O ₁ ) formed at a desired pitch (p)
₁₁ , O ₁₂ , ... O _1m ; m ≧ 2). In FIG. 1, the first row of wire tension members is designated as W ₁ . Therefore, the metal wire (W) of the present invention
From the viewpoint of the wire stretched body, is applied to each wire stretched body W _{1 to} W _n .

In order to achieve the same level of exhaust gas purifying ability as the wound or laminated type metal honeycomb body composed of the conventional flat plate-shaped strip material and corrugated plate-shaped strip material shown in FIGS. , The following numerical settings will be helpful. For example, φ60.5m
In order to achieve a purifying ability equivalent to that of a cylindrically wound metal honeycomb body (cell density, 100 cpsi) having a length of m and a length of 40 mm, the metal carrier of the present invention is used for an exhaust gas purifying catalyst. It is necessary to have an equivalent support surface area. In this case, one side is 53.6 mm, and the spacing between each wire is 1.0
Considering the rectangular type metal carrier of the present invention of mm (p = d = 1.0 mm), the wire diameter φ of the metal wire is calculated by simple calculation.
100 steps at 0.2 mm (n = 100, total wire length 2
70m), 50 when metal wire diameter φ = 0.4mm
It is a step (n = 50, total wire length 140m).

In the metal carrier (MS) of the present invention, the material of the metal casing (C) is as shown in FIGS.
The heat-resistant steel of the same type as that used in the production of the conventional metal honeycomb body shown in 1 may be used, or the one having a high heat-corrosion resistance may be used. When the metal material of the outer part is richer in heat resistance and corrosion resistance than the inner part, it has a double structure, specifically, it uses ferritic stainless steel for the inner part and austenitic stainless steel for the outer part. May be used.

In the metal carrier (MS) of the present invention, the material of the metal wire (W) is a flat strip (foil) used in the production of the conventional metal honeycomb body shown in FIGS. Material) or corrugated strip material (foil material)
Those having the same characteristics as those described above, that is, the materials having excellent high temperature oxidation resistance are preferable. For example, Fe-20Cr-5A
A wire material such as a product made of a metal alloy or a material obtained by adding REM thereto is used. The wire diameter of the metal wire (W) may be about the thickness of the band material, and is generally 0.05.
~ 0.5 mm is used. Although the cross-sectional shape of the metal wire (W) is generally circular, it may be a different shape such as an ellipse, a polygon, or a rectangle, or a combination thereof.

A second embodiment of the metal carrier (MS) of the present invention is shown simultaneously in FIG. That is, in the second embodiment, the hole forming element _{(O 1, O 2, .........} O n; n
The arrangement direction of the metal wire arranged in the hole of ≧ 2) is
It is characterized by being in different directions. In FIG.
Point above the first row in the (n = 1) Metal wire in Zhang設体(W ₁₎ and the 10 rows (n = 10) Metal-clad in設体(W _10), the direction of arrangement of metal wires It is shown to be orthogonal. Arrangement of the metal wires (W) in the first to n-th row metal wire tension bodies (W _{1 to} W _n ) in comparison with those in which the metal wires (W) are all arranged in the same direction. If the directions are orthogonal to each other, for example, the exhaust gas flow collides with the wire material inside the metal carrier, whereby the exhaust gas is agitated and mixed, and becomes turbulent. Therefore, the catalytic reaction with the exhaust gas purifying catalyst carried on the surface of the metal wire (W) is made efficient, so that the exhaust gas purifying ability becomes excellent.

2 to 4 particularly illustrate the manner of disposing the metal wire (W) on the metal casing (C) and the mode of the fixing means. FIG. 2 shows that each hole forming part (O ₁ , O ₂ , ..., On _n ; n ≧ 2), for example, m holes (O ₁₁ ) formed in the hole forming part (O ₁ ) of the first example. , O ₁₂ , ... O _1m ; m ≧ 2), a plurality of metal wires (W ₁₁ , W) are provided between the opposing holes.
₁₂ , W ₁₃ .....) will be stretched, and the metal casing (C) will be fixed by welding at the hole and its vicinity. 3 to 4 show that each hole forming part (O ₁ , O ₂ , ..., On _n ; n ≧ 2), for example, m holes formed in the first row hole forming part (O ₁ ). In (O ₁₁ , O ₁₂ , ... O _1m ; m ≧ 2), one metal wire (W ₁₁ ) is sequentially stretched between opposing holes so as to be woven in a zigzag shape (see FIG. 3). ), And then, a mode in which the casing (C) is fixed by brazing at and around the hole.

[0018]

Industrial Applicability The metal carrier (MS) for carrying the exhaust gas purifying catalyst of the present invention comprises various types of conventional flat strip material (foil material) and corrugated strip material (foil material). Compared with a metal carrier whose main component is a metal honeycomb body having a type of honeycomb structure, a metal wire material is arranged in a metal casing in a predetermined method in relation to a metal casing. Therefore, the following excellent effects are obtained. (i) In contrast to the conventional strip material (foil material), since the present invention has a structure in which wires are arranged in a metal casing, deformation due to large thermal stress generated inside the metal carrier when the metal carrier is used Since the force can be absorbed and relieved by the wire portion, it has excellent durability. In this respect, the conventional strip material (foil material) has a low ability to absorb and relax the deformation force. (ii) In contrast to the conventional strip material (foil material), since the present invention is a wire array, the exhaust gas flow can be agitated, mixed, and turbulent between the wires. The contact efficiency with the exhaust gas purifying catalyst carried on the wire surface is improved, and the purifying ability can be improved. In this respect, the conventional strip material (foil material) requires a special mechanism for turbulence. (iii) Although the conventional strip material (foil material) is extremely expensive, the metal carrier composed of the wire array of the present invention is inexpensive, and the cost merit can be obtained. (iv) Comparing with a conventional metal honeycomb body having a honeycomb structure using a strip material (foil material), complicated steps and expensive manufacturing equipment are not required, and a cost merit can be obtained also in this respect.

[Brief description of drawings]

FIG. 1 is a perspective view showing a part of a metal carrier according to the present invention as seen through and partly omitted.

FIG. 2 is a diagram for explaining an arrangement mode and a fixing mode of a metal casing and a metal wire which constitute the metal carrier of the present invention.

FIG. 3 is a diagram for explaining another arrangement mode of the metal casing and the metal wire that form the metal carrier of the present invention.

FIG. 4 is a diagram for explaining a fixing mode of the metal wire arrangement body shown in FIG.

FIG. 5 is a perspective view of a conventional winding type metal honeycomb body.

FIG. 6 is a perspective view of a conventional laminated-type metal honeycomb body.

[Explanation of symbols]

MS ......... metal carrier C ......... metal casing O (O ₁ ~O _n) ......... hole forming portion _{O 11, O 12, O 13} ......... hole W ......... metal wires W ₁ to _W-n ... …… Metal wire array W ₁₁ , W ₁₂ , W ₁₃ ………… Wire material MS´ ………… Conventional metal carrier H ………… Conventional metal honeycomb body

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location F01N 3/28 301 P 311 S

Claims (7)

[Claims] 1. A metal carrier for carrying an exhaust gas purification catalyst comprising a metal casing made of heat-resistant steel and a metal wire, comprising: (i) the metal casing having a desired spacing (d ₁ , d ₂ , ... ...... d _n−1 ; n ≧ 2), and the hole forming portions (O ₁ ,
O ₂ , ..., O _n ; n ≧ 2), and a desired number of holes are formed at a desired pitch (p) in each hole forming portion, and (ii) The metal wire is connected to the hole forming portions (O ₁ ,
A metal carrier characterized in that it is arranged in a hole of O ₂ , ..., O _n ; n ≧ 2). 2. In each of the hole forming portions (O ₁ , O ₂ , ..., O _n ; n ≧ 2) which are parallel to each other, a metal wire is arranged in the hole of the hole forming portion. Direction
The metal carrier according to claim 1, which is in the same direction. 3. Arrangement of metal wires arranged in the holes of the hole forming portions in each of the hole forming portions (O ₁ , O ₂ , ..., O _n ; n ≧ 2) which are parallel to each other. Direction
The metal carrier according to claim 1, which has different directions. 4. A metal wire is provided for each hole forming portion (O ₁ ,
_2. The metal carrier according to claim 1, wherein the metal carrier comprises a plurality of O ₂ , ..., O _n ; n ≧ 2) each having a length between holes facing each other. 5. A metal wire is provided for each hole forming portion (O ₁ ,
The metal carrier according to claim 1, wherein the metal carrier has a length such that O ₂ , ..., O _n ; n ≧ 2) can be woven in a zigzag shape in the holes of the hole forming portion. 6. The metal honeycomb body according to claim 1, wherein the metal wire is fixed to the hole provided in the outer wall of the metal casing and a portion in the vicinity thereof. 7. The metal honeycomb body according to claim 6, wherein the fixing means is brazing or welding.