JPH06392A - Metallic catalyst carrier - Google Patents

Abstract

PURPOSE:To considerably reduce the risk of damaging the flat sheets of a metallic catalyst carrier used in a catalytic converter for an automobile, industrial vehicles, etc. CONSTITUTION:When corrugated sheets 31 and flat sheets 33 each made of a metal are alternately laminated to obtain a metallic catalyst carrier, the thickness of the flat sheets 33 is made smaller than that of the corrugated sheets 31. Thermal stress is transferred to the corrugated sheets and the internal stress of the flat sheets is relieved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal catalyst carrier used in a catalytic converter for automobiles, industrial vehicles and the like.

[0002]

2. Description of the Related Art Generally, a catalytic converter is arranged in an exhaust system of an automobile in order to purify exhaust gas. In the catalytic converter, for example, Japanese Patent Laid-Open No. 2-2808 is used.
The metal catalyst carrier as disclosed in Japanese Patent Laid-Open No. 42 is accommodated.

FIG. 4 shows a metal catalyst carrier of this kind. As shown in FIG. 5, this metal catalyst carrier is composed of corrugated plates 11 and flat plates 13 made of metal, which are alternately superposed on each other to form a circular shape. It is formed by crushing into an elliptical shape after being wound into.

After the contact portions between the corrugated plate 11 and the flat plate 13 are fixed to each other by brazing, diffusion bonding, etc.,
For example, as shown in FIG. 6, it is used by being housed in a cylindrical container 15.

[0005]

However, in such a metal catalyst carrier, there has been a problem that the flat plate 13 is often damaged by thermal stress repeatedly acting on the corrugated plate 11 and the flat plate 13.

The present inventor has conducted extensive studies in order to solve such conventional problems, and as a result, in the conventional metal catalyst carrier,
As shown in FIG. 7, since the corrugated plate 11 and the flat plate 13 have the same plate thickness t, the rigidity of the flat plate 13 is larger than that of the corrugated plate 11 which is formed in a wave shape and is relatively deformable. Corrugated sheet 11
It was found that a large thermal stress acts on the flat plate 13 as compared with the above.

That is, when hot exhaust gas flows into the metal catalyst carrier, the corrugated plate 11 and the flat plate 13 become hot, and thermal stress is generated toward the outside as shown by arrows in FIG. Since the temperature of the tubular container 15 is lower than the temperatures of the corrugated plate 11 and the flat plate 13, the thermal expansion of the tubular container 15 is relatively small, and as a result, the thermal expansion of the corrugated plate 11 and the flat plate 13 is small. It is blocked by the cylindrical container 15, and the thermal stress between the corrugated plate 11 and the flat plate 13 is relieved.

However, in the conventional metal catalyst carrier, the rigidity of the flat plate 13 is higher than that of the corrugated plate 11 formed in a corrugated shape, so that the thermal stress generated between the corrugated plates 11 and 13 is generated. In comparison with the above, the flat plate 13 becomes very large, and as a result, the flat plate 13 is easily damaged.

In the metal catalyst carrier disclosed in Japanese Unexamined Patent Publication No. 2-280842, as shown in FIG. 8, between the metal catalyst carrier 17 including the corrugated plate 11 and the flat plate 13 and the cylindrical container 15. The reinforcing corrugated plate 19 having a plate thickness sufficiently larger than that of the corrugated plate 11 and the flat plate 13 is arranged in the above, but this does not directly prevent the thermal expansion of the corrugated plate 11 and the flat plate 13 by the tubular container 15. , The corrugated plate 11 and the flat plate 13 are blocked by the reinforcing corrugated plate 19 which is relatively elastically deformable.
It is intended to absorb the thermal expansion of and to reduce the thermal stress generated in the corrugated plate 11 and the flat plate 13.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a metal catalyst carrier capable of significantly reducing the risk of plate damage.

[0011]

A metal catalyst carrier according to the present invention is a metal catalyst carrier in which metal corrugated plates and flat plates are alternately laminated, and the plate thickness of the flat plate is the plate thickness of the corrugated plate. It is made smaller than the thickness.

[0012]

In the metal catalyst carrier of the present invention, the thickness of the flat plate is made smaller than that of the corrugated plate, so that the rigidity of the flat plate is reduced, the flat plate is easily thermally deformed, and the thermal stress is transmitted to the corrugated plate. As a result, the stress of the flat plate is relieved, and the thermal deformation of the corrugated plate and the flat plate is prevented by the tubular container, whereby the thermal stress is relieved and breakage can be prevented.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an embodiment of the metal catalyst carrier of the present invention. This metal catalyst carrier is formed by winding a metal corrugated plate 31 and a flat plate 33 in an elliptical shape and stacking them in multiple layers. ing.

The metal catalyst carrier is housed in an elliptic cylindrical container 35. Therefore, in this embodiment, as shown in FIG. 2, the plate thickness t _{f of the} flat plate 33 is smaller than the plate thickness t _w of the corrugated plate 31.

The plate thickness t of the flat plate 33 is_fOf the corrugated plate 31
Thickness t_wIt is desirable to set it to 0.5 to 0.9 times. this
In the embodiment, the plate thickness t of the flat plate 33 is_fIs 40 μm,
Thickness t of corrugated sheet 31 _wIs 50 μm.

The contact portion between the corrugated plate 31 and the flat plate 33 is
They are fixed to each other by brazing, diffusion bonding, etc. In the metal catalyst carrier configured as described above, since the plate thickness t _{f of the} flat plate 33 is made smaller than the plate thickness t _w of the corrugated plate 31,
The rigidity of the flat plate 33 is reduced, the thermal deformation of the flat plate 33 is prevented by the tubular container 35, and the thermal stress generated in the flat plate 33 is reduced. It can be reduced.

That is, in the conventional metal catalyst carrier, since the corrugated plate and the flat plate have the same plate thickness, the rigidity of the flat plate is very large as compared with the corrugated plate which is formed in a wavy shape. The thermal stress generated in the corrugated plate and the flat plate without the thermal expansion of the corrugated plate and the flat plate being blocked by the cylindrical container was extremely large in the flat plate as compared with the corrugated plate. In the metal catalyst carrier of, the thickness of the flat plate 33 is
Since the thickness of the flat plate 33 is smaller than that of No. 1, the rigidity of the flat plate 33 is small, and the thermal stress generated in the flat plate 33 is small because the thermal expansion of the flat plate 33 is blocked by the cylindrical container 35.
The risk of breakage of the flat plate 33 can be significantly reduced as compared with the related art.

On the other hand, since the flat plate 33 is easily deformed by heat,
Although the thermal deformation of the corrugated plate 31 is prevented by the tubular container 35, the thermal stress generated in the corrugated plate 31 becomes large, but the corrugated plate 31 is more likely to be elastically deformed than the flat plate 33, and thus may be damaged. There is no.

That is, by making the plate thickness of the flat plate 33 smaller than the plate thickness of the corrugated plate 31, it becomes possible to more evenly distribute the thermal stress between the corrugated plate 31 and the flat plate 33. Figure 3
Shows the result of the thermal cycle test of the above-mentioned metal catalyst carrier. The horizontal axis shows the plate thickness t _{f of the} flat plate 33, and the vertical axis shows the number of loaded thermal cycles.

In this test, the corrugated plate 31 has a plate thickness t _w
Were all 50 μm. From the figure, in the case of the metal catalyst carrier in which the plate thickness of the flat plate 33 is the same as the plate thickness of the corrugated plate 31, that is, the plate thickness of the flat plate 33 is 50 μm and the plate thickness of the corrugated plate 31 is 50 μm, it is shown at point a in the figure. As described above, the flat plate 33 is fractured after 150 thermal cycles.
Of the corrugated plate 31 is smaller than that of the corrugated plate 31, that is, the plate thickness of the flat plate 33 is 40 μm and the plate thickness of the corrugated plate 31 is 50 μm.
In the case of the metal catalyst carrier of No. 2, 200
It can be seen that the flat plate 33 is fractured by the heat cycles.

That is, in the metal catalyst carrier of this embodiment, the life is improved by the amount corresponding to 50 heat cycles. On the other hand, the plate thickness of the flat plate 33 is larger than the plate thickness of the corrugated plate 31, that is, the plate thickness of the flat plate 33 is 150 μm and the plate thickness of the corrugated plate 31 is 50 μm.
As shown by the points, the flat plate 33 is fractured after about 10 thermal cycles, and it can be seen that the life is very short.

In the present invention, the plate thickness t of the flat plate 33 is
_It is desirable to set _f to be 0.5 to 0.9 times the plate thickness t _w of the corrugated plate 31. If it is less than 0.5 times, the strength of the flat plate 33 will be small and the shape of the metal catalyst carrier will be sufficient. It is difficult to maintain the above value. On the other hand, when it exceeds 0.9 times, the sufficient effect cannot be obtained due to the high rigidity.

In the above-mentioned embodiment, the example in which the present invention is applied to the metal catalyst carrier formed by winding the corrugated plate 31 and the flat plate 33 is described, but the present invention is limited to such an embodiment. It is needless to say that the present invention can be similarly applied to, for example, a metal catalyst carrier or the like in which a corrugated plate cut into a predetermined shape and a flat plate are simply stacked and laminated.

[0024]

As described above, in the metal catalyst carrier of the present invention, the plate thickness of the flat plate is made smaller than that of the corrugated plate, so that the flat plate is prevented from being thermally deformed by the cylindrical container. There is an advantage that the thermal stress generated in the plate is reduced and the risk of the flat plate being broken can be greatly reduced compared to the conventional case.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a metal catalyst carrier of the present invention.

FIG. 2 is an enlarged sectional view showing the corrugated plate and the flat plate of FIG.

FIG. 3 is an explanatory diagram showing a result of a thermal cycle test of the metal catalyst carrier of FIG.

FIG. 4 is a perspective view showing a conventional metal catalyst carrier.

FIG. 5 is a perspective view showing a state in which a corrugated plate and a flat plate are wound.

FIG. 6 is an explanatory view showing a state where the metal catalyst carrier of FIG. 4 is housed in a cylindrical container.

7 is an enlarged sectional view showing the corrugated plate and the flat plate of FIG.

FIG. 8 is an explanatory view showing a conventional metal catalytic converter.

[Explanation of symbols]

 31 corrugated plate 33 flat plate

Claims (1)

[Claims] 1. A metal catalyst carrier comprising metal corrugated plates (31) and flat plates (33) alternately laminated, wherein the plate thickness of the flat plates (33) is the same as the plate thickness of the corrugated plates (31). A metal catalyst carrier characterized by being made smaller.