JP3202094B2 - Metal carrier for catalyst device and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal carrier for a catalyst device used in an exhaust gas purifying device of an internal combustion engine and a method for producing the same, and more particularly to a metal carrier forming a honeycomb formed in a roll shape.

[0002]

2. Description of the Related Art As shown in FIG. 2 (A), a metal carrier for a catalyst device used in a conventional exhaust gas purifying device has a flat plate shape.
3 and a corrugated plate 34 stacked and rolled into a roll-shaped honeycomb body 3
1 is formed, and the honeycomb body is housed in a metal outer cylinder 32 (for example, JP-A-56-4373).
No.). In this metal carrier, a flat plate and a corrugated plate constituting the honeycomb body, and an outer cylinder and the honeycomb body are usually integrally joined by brazing. A catalyst supporting layer made of alumina or the like is formed on the surface of the honeycomb passage of the honeycomb body, and the noble metal catalyst is supported on the catalyst supporting layer to serve as an exhaust gas purifying catalyst. And it is disposed in an exhaust passage of an internal combustion engine for purifying HC in exhaust gas, CO, etc. NO _x. Since it is necessary to secure as many honeycomb passage areas as possible in a limited volume, the thicknesses of the flat plate and the corrugated plate are made as thin as possible within a range where strength can be maintained.

Further, a honeycomb body having a flat plate thickness larger than that of a corrugated plate (Japanese Utility Model Laid-Open No. 63-77634) and a honeycomb body having two flat plates are disclosed.

[0004]

FIG. 2B is a schematic partial schematic view of a cross section perpendicular to the axis of the conventional metal carrier 30 for the catalyst device shown in FIG.
Is represented by 33 _{1 for} the flat plate of the outermost layer and 33 ₂ ,... (The same applies hereinafter) for the flat plate of the second layer from the outermost layer.
The corrugated sheet of the outermost layer is 34 ₁ , and the corrugated sheet of the second layer from the outermost layer is 34 _1
2 ,... (The same applies hereinafter). a and b represent the brazing material interposed at the contacting point, and a ₁ represents the outer cylinder 32.
A ₂ is the outermost corrugated plate 34 ₁ between the outermost flat plate 33 ₁ and
If between the flat plate 33 ₂ of the second layer represents a brazing material interposed ... (the same applies hereinafter), b ₁ between the corrugated plate 34 ₁ of the outermost layer of the flat plate 33 ₁ and the outermost layer, b ₂ is the second flat plate 33 ₂ and 2
Between the corrugated plate 34 ₂ layers th represents the brazing material interposed ... (hereinafter the same). FIG. 2 (C) is the same as FIG.
3 is a schematic view of an axial section taken along line XX of FIG.

[0005] In the above-mentioned conventional metal carrier for a catalytic device, the flow velocity of the exhaust gas passing through the honeycomb body is larger as it goes from the outer layer part to the inner layer part of the honeycomb body. Due to the heat generated by the catalytic reaction and the heat dissipation from the outer cylinder, a temperature distribution is generated such that the inner layer has a higher temperature and the outer layer has a lower temperature. Due to this temperature distribution, the amount of expansion and contraction of the inner layer of the high-temperature honeycomb body is larger than the amount of expansion and contraction of the outer layer of the lower temperature, so that thermal stress is generated between the inner layer and the outer layer. I do. This thermal stress is repeated each time the honeycomb body expands and contracts,
Particularly remarkable effects between the flat plate 33 ₁ and the corrugated 34 ₁ of the outermost layer portion movement of expansion and contraction is restricted by the outer tube 32, the corrugated plate 34 ₁ of the outermost plastic deformation of the honeycomb body 31 for the electromotive As a result, there is a drawback that metal fatigue occurs and finally breaks. Figure 3 is an explanatory view showing a state where the rupture of the FIG. 3 (A), the difference in elongation or contraction caused by thermal expansion and the temperature difference between the outer tube 32 and the outermost layer of the flat plate 33 ₁ deflection of the plate 33 ₁ by the, shows the state of pressing the corrugated plate 34 ₁ of the outermost layer, resulting diagram 3 (B)
As shown in ( ₁ ), the largest stress is generated in the brazed portion of the corrugated plate 341 having a small joining area, and the repetition of the stress causes a crack, eventually leading to breakage, and the honeycomb body 31 may fall off from the broken portion. .

Further, in the case of a honeycomb body in which the thickness of the flat plate of the honeycomb body is made larger than that of the corrugated plate, or in the case of a honeycomb body in which two flat plates are stacked, the rigidity of the honeycomb body is ensured by the flat plate. It can be prevented,
By stacking the sheets, the air resistance of the flat plate in the exhaust passage is increased, and the exhaust performance is reduced. In addition, the weight of the metal carrier is increased, and thus the cost is increased.

An object of the present invention is to provide a novel metal carrier for a catalyst device which does not cause metal fatigue due to thermal stress on a corrugated sheet in an outer layer portion of a honeycomb body and does not deteriorate exhaust performance.

[0008]

A metal carrier for a catalyst device according to the present invention is formed by laminating a thin metal strip-shaped flat plate and a strip-shaped corrugated sheet so as to abut against each other and winding them into a roll shape. An outer surface of a corrugated plate in a range of at least two layers or more from the outside of the honeycomb body in a catalyst device metal carrier having a honeycomb body having a large number of mesh-shaped air passages and an outer cylinder covering the outer surface of the honeycomb body. Alternatively, one of the inner surfaces is not joined to the contacting flat plate, and the other corrugated plate and the flat plate are joined to each other via the brazing material at the contacting positions.

The method for producing a metal carrier for a catalytic device according to the present invention is characterized in that a thin metal strip-shaped flat plate and a strip-shaped corrugated sheet are stacked so as to abut each other, and a brazing material is interposed therebetween to form a roll. In a portion where at least one of the outer surface and the inner surface of the corrugated sheet in the range of at least two layers from the outermost periphery is in contact with the flat plate, the corrugated sheet is wound without interposing a brazing material and the honeycomb. In this method, a honeycomb body is housed in an outer cylinder, and the honeycomb body and the outer cylinder, and a flat plate and a corrugated sheet provided with the brazing material of the honeycomb body are joined to each other.

[0010]

[Function] The joint between the outermost flat plate and the corrugated plate, which has the greatest influence of expansion and contraction due to the temperature difference between the outer and inner layers, has been eliminated, so that the stress due to the thermal deformation of the outermost flat plate is directly reduced to the outermost layer. No longer reach the corrugated sheet.

[0011]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic partial cross-sectional view of one embodiment of a metal carrier for a catalyst device of the present invention. FIG. 1 (A) is a schematic cross-sectional view in a direction perpendicular to an axis O of a honeycomb body, and FIG.
It is an axial section schematic diagram containing line XX of (A).

Plate 3₁ , 3_Two , 3_Three ... is thin metal
Honeycomb formed by winding a band-shaped flat plate into a roll
Represents the cross section of the body, the subscript is the layer counted from the outermost layer
The ordinal number of Corrugated sheet 4₁ , 4_Two , 4_Three ...
Is formed by winding a thin metal strip corrugated sheet into a roll
Indicates the cross section of the honeycomb body, and the subscript is the outermost
Shows the ordinal number of the layer counted from the layer. Circumferential outside of flat plate
The brazing material interposed on the surface is a
B denotes the brazing material interposed on the outer surface of the
Depending on the ordinal number of the layer of the plate counted, the outer surface of the plate
A₁₁, A₁₂, A₁₃... indicated by the inner surface of the flat plate
The brazing material on the outer surface of the corrugated sheet b₁₁, B₁₂, B₁₃・ ・ ・ ・ Table
I do. In this embodiment, the second to outermost layers are used.
Brazing material b on the outer surface of the corrugated sheet₁₁, B₁₂Is interposed
And the third and subsequent brazing filler metals b₁₃Interposed from outside the flat plate
On the surface, ie the inner surface of the corrugated sheet,
Lumber is interposed. Therefore, the flat plate 3₁ And corrugated sheet 4₁ 
Between and flat plate 3_Two And corrugated sheet 4 _Two Are joined between
Instead, they are merely in contact. Outer cylinder 2 is rolled
The outermost flat plate 3 is a tube that covers the formed honeycomb body.
₁ Brazing material a₁₁To form a metal carrier 10
are doing.

[0013] FIG. 1 (C) is a axial cross-sectional schematic view of the metal carrier 10 'of the second embodiment, the brazing material a ₁₂ of the inner side surface of the outermost layer is a wave plate to the second layer, a ₁₃ has not been interposed, it is interposed after the third layer from the braze a _14, in the outer surface of the inner surface or corrugated sheets of flat plate, the brazing material is interposed all layers. Accordingly, wave plate 4 ₁ and the flat plate 3
Between ₂ and between the corrugated sheet 4 ₂ and the flat 3 ₃ not joined, it is merely in contact with. The outer cylinder 2 is joined to the honeycomb body as in the first embodiment, and
0 'is formed.

The above two embodiments describe the configuration of the metal carrier in which either the outer surface or the inner surface from the outermost layer to the second layer of the honeycomb corrugated sheet is not joined to the abutting flat plate. However, it is clear that the present invention can constitute a metal carrier in which either the outer surface or the inner surface of the corrugated sheet in a range exceeding the second layer of the corrugated sheet is not joined to the abutting flat plate.

[0015] Next, the metal carrier of the present invention is provided with a high-temperature exhaust gas.
Fig. 1 (D) explains the operation when contacting
I will tell. FIG. 1 (D) shows a method of the embodiment shown in FIG. 1 (B).
Shows the state when the thermal support is subjected to thermal stress.
Plate 3 on the warm side₁ Is expanded and collected by the outer cylinder 2 on the low temperature side.
The movement of shrinkage is regulated, and flat plate 3₁ Is bent
But flat plate 3₁ And corrugated sheet 4 that abuts it₁ Is joined
Because it is not flat 3 ₁ Of the corrugated sheet 4₁ Expansion and contraction
Is not a burden. Therefore corrugated sheet 4₁ Cracks
Not subject to the stresses that occur.

[0016]

As described above, according to the present invention, the roll-shaped honeycomb body is formed by joining at least one of the outer surface and the inner surface of the corrugated plate in at least two layers from the outside to the flat plate with which the corrugated plate abuts. By constructing it so as not to cause metal fatigue due to thermal stress on the corrugated sheet of the outermost layer of the honeycomb body,
In addition, there is an effect that the exhaust performance is not reduced.

[Brief description of the drawings]

1 is a schematic partial cross-sectional view of a metal carrier for a catalyst device according to the present invention, wherein FIG. 1 (A) is a cross-sectional schematic view perpendicular to an axis of a honeycomb body, and FIG. 1 (B) is a line X in FIG. 1 (C) is an axial cross-sectional schematic view of the second embodiment, and FIG. 1 (D) is a state when the metal carrier of FIG. 1 (B) is subjected to thermal stress. FIG.

FIG. 2 is a schematic view of a conventional metal carrier for a catalyst device,
2 (A) is a perspective view, FIG. 2 (B) is a schematic partial cross-sectional view perpendicular to the axis of the honeycomb body, and FIG. 2 (C) is an axial cross-sectional schematic view including line XX in FIG. 2 (B). It is.

FIG. 3 is an axial cross-sectional view of a conventional metal carrier for a catalytic device.
It is explanatory drawing of the state which will be broken by thermal stress.

[Explanation of symbols]

2,32 outer cylinder 3 _1, 3 _{2, 3} 3 ... flat (subscript outermost second layer represents a third layer, ...) 4 _1, 4 _2, 4 ₃ ... · corrugated plate (subscript outermost second layer represents a third layer, ...) 10, 10 ', 30 metal carrier 31 honeycomb body 33 flat 33 _1, 33 _2, 33 ₃ ... flat (Subscripts represent outermost layer, second layer, third layer, etc.) 34 Corrugated sheet 34 ₁ , 34 ₂ … Corrugated sheet (subscripts represent outermost layer, second layer, ...) ) A ₁ , a ₂ , a ₃ .
B ₁ , b ₂ , b ₃ ... B1, b ₂ , b ₃ .
Outermost, second layer, third layer represents the _{····) a 11, a 12,} a 13 ···· flat outer surface brazing material (subscript
Outermost, second layer, refers to roughness and third layer _{····) b 11, b 12,} b 13 ···· wave plate outer surface brazing material (subscript
O represents the outermost layer, second layer, third layer, etc.) O Honeycomb body axis

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B01J 21/00-37/36 B01D 53/86 F01N 3/28

Claims (2)

(57) [Claims] 1. A honeycomb body having a plurality of mesh-shaped air passages formed by laminating a thin metal strip-shaped flat plate and a strip-shaped corrugated sheet so as to abut each other and winding the roll into a roll shape. A metal carrier for a catalyst device having an outer cylinder that covers the outer surface of the body, wherein one of the outer surface and the inner surface of the corrugated plate in the range of at least two layers from the outside of the honeycomb body is in contact with the honeycomb body A metal carrier for a catalyst device, characterized in that a corrugated plate and a flat plate other than the above are bonded via a brazing material at portions where they are in contact with each other without being bonded to the flat plate. 2. A thin metal strip-shaped flat plate and a strip-shaped corrugated sheet are overlapped with each other so as to be in contact with each other, and a brazing material is interposed therebetween and wound in a roll shape. In a place where either the outer surface or the inner surface of the corrugated sheet in the range of the above comes into contact with the flat plate, the sheet is wound without interposing a brazing material to form a honeycomb body, and the honeycomb body is formed of an outer cylinder. A method of manufacturing a metal carrier for a catalyst device, wherein the flat plate and the corrugated plate, which are housed in a honeycomb body and the honeycomb body and the brazing material of the honeycomb body, are joined to each other.