JP2558557Y2 - Tandem metal carrier - 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 catalyst tandem type metal carrier used for purifying exhaust gas emitted from an automobile engine or the like.

[0002]

2. Description of the Related Art As a catalyst carrier for purifying exhaust gas, a catalyst carrier formed of a honeycomb body using heat-resistant metal foil has been developed.
Some are already in practical use. In recent years, in order to further improve the catalyst performance, a tandem carrier in which two honeycomb bodies are brazed and held in one outer cylinder is about to be used as an automobile catalyst. That is, such a tandem carrier is shown in FIG.
As shown in the figure, an upper honeycomb body 2 is provided in one outer cylinder 1,
The lower honeycomb body 3 is rigidly joined to each other at a brazing portion.

When such a metal catalyst carrier is mounted on an exhaust gas system of an automobile engine, the carrier repeatedly undergoes a severe heat cycle of rapid heating and rapid cooling from the start to the stop of the engine. The upper honeycomb body of the tandem metal carrier has a small honeycomb volume, so the temperature rises quickly and becomes high, and the thermal expansion and contraction between the upper metal honeycomb body and the outer cylinder is large, so the outer cylinder and the honeycomb body are joined. The stress concentrates on the portion where the film is formed, and peeling occurs, which is not preferable.

[0004]

In the case where the length of the honeycomb body is long, a flat foil and a corrugated foil are joined in a partial cross section, and the outer periphery of the honeycomb body and the outer cylinder are joined, for example, as disclosed in Japanese Utility Model Application Laid-Open No. Sho 62-194436. A method has been proposed in which the inner circumference is joined with a partial width in the axial direction, and a non-joining surface is provided to measure stress relaxation.However, when the honeycomb body length is as short as about 10 to 30 mm, a flat foil is used. Since the joining portion in the partial cross section of the corrugated foil and the joining portion of the honeycomb body and the outer cylinder approach or overlap with each other, stress concentration tends to occur, and if the length of the honeycomb body is short, bending deformation due to exhaust gas pressure in the honeycomb body diameter direction. And lead to destruction.

According to the present invention, the upper metal honeycomb body (hereinafter referred to as upper honeycomb body) and the outer cylinder are held by a stress relaxation structure which does not directly join the outer periphery of the upper honeycomb body and the inner circumference of the outer cylinder.
Further, the upper honeycomb body provides a tandem-type metal carrier which is prevented from being deformed by being joined to a retainer.

[0006]

According to the present invention, two honeycomb bodies formed by superimposing a flat foil and a corrugated foil made of a heat-resistant metal and spirally winding or laminating them are formed on an outer cylinder made of a heat-resistant metal. In the metal catalyst carrier to be housed and fixed, the upper honeycomb body is joined and held by a retainer provided therebelow, the retainer is joined and fixed to the outer cylinder, and the lower metal honeycomb body (hereinafter referred to as a lower honeycomb body) is fixed. A tandem-type metal carrier that is fixed to a cylinder by brazing.

That is, the upper honeycomb body is focused on the fact that the length of the honeycomb body is as short as about 10 to 30 mm and low in weight and weight, and the upper honeycomb body is supported by a retainer and housed in an outer cylinder. By joining a honeycomb body and a retainer provided below the honeycomb body, the upper honeycomb body is prevented from bending. Also, by joining the upper honeycomb body and the retainer provided at the lower part, rattling of the upper honeycomb body can be prevented. The joining between the upper honeycomb body and the retainer may be performed on the entire contact portion or on a part thereof. Further, the joining of the honeycomb bodies may be a brazing structure or a welding structure.

Next, the present invention will be described in detail based on an embodiment shown in the drawings. FIG. 1A and FIG. 1B showing an XX cross section thereof are examples of the present invention. Reference numeral 1 denotes an outer cylinder, which houses an upper honeycomb body 2 and a lower honeycomb body 3. Reference numeral 6 denotes an upper honeycomb body receiving / fixing cross retainer fixed to the inner periphery of the outer cylinder 1, 7 denotes a brazing portion between the upper honeycomb body 2 and the retainer 6, and 8 denotes a welded portion between the retainer 6 and the outer cylinder 1. is there. Reference numeral 5 denotes a brazing portion between the lower honeycomb body 3 and the outer cylinder 1.

That is, the conventional tandem-type honeycomb body has a problem that the thermal expansion and contraction with the outer cylinder is large due to the small capacity of the upper honeycomb body 2 so that peeling easily occurs. As shown in FIG. 1, the upper honeycomb body 2 is fixed by using a cross-shaped retainer 6 for fixing, and the upper honeycomb body 2 is held in the outer cylinder 1 so as to have a stress relaxation structure. It solves the problem. Lower honeycomb body 3 and outer cylinder 1
In this case, a part of the axial direction may be brazed.

The retainer 6 for fixing and receiving the honeycomb body is not limited to the cross-shaped support but may be formed in a single straight line or in a radial shape. This shape should be considered so as not to increase the pressure loss of the gas flow. , Do not specify.

FIG. 2 shows another example of the present invention, wherein FIG. 2 (a) is an overall sectional view, and FIGS. 2 (b) and 2 (d) are (a).
(C) and (e) are bottom views of (b) and (d). That is, the lower honeycomb body 3 is directly accommodated in the outer cylinder 1 as shown in (d) and (e) of FIG. (b), (c) and (f), as shown in the drawings, housed in a retainer 6 having a cylindrical or plate-like side wall 6 ', and brazed
This is housed in the outer cylinder 1, and the side wall 6 ′ of the retainer 6 and the outer cylinder 1 are joined by welding 8. As described above, by individually manufacturing the upper and lower honeycomb bodies, excellent productivity can be obtained.

[0012]

According to the tandem carrier of the present invention, it is possible to prevent the carrier from being peeled and damaged between the outer cylinder and the honeycomb body, and the effect is extremely large.

[Brief description of the drawings]

1A is a longitudinal sectional view of the carrier of the present invention, and FIG. 1B is a sectional view taken along line XX of FIG. 1A.

2A is a longitudinal sectional view of another example of the present invention, FIG. 2B is a longitudinal sectional view of an upper honeycomb body part of FIG. 2A, FIG. 2C is a bottom view of FIG. (d) is a longitudinal sectional view of the lower honeycomb body part of (a), (e) is a bottom view of (d), and (f) is a bottom view showing another example of (b).

FIG. 3 shows a longitudinal sectional view of a conventional carrier.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer cylinder 2 Upper honeycomb body 3 Lower honeycomb body 4,5,7,8 Brazing part 6 Retainer 6 'Retainer side wall

Claims (1)

(57) [Scope of request for utility model registration] 1. A metal foil for storing and fixing two honeycomb bodies formed by superimposing a flat foil and a corrugated foil made of a heat-resistant metal and spirally winding or laminating them in an outer cylinder made of a heat-resistant metal. A tandem-type metal carrier comprising a catalyst carrier, wherein a lower portion of an upper honeycomb body is joined to a retainer joined and held to an outer cylinder, and a lower honeycomb body is fixed to the outer cylinder by brazing.