JPH0583315U - Tandem type metal carrier - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention provides a tandem metal carrier,
A tandem-type metal carrier with less peeling is provided by fixing the upper honeycomb body to the outer cylinder under severe temperature conditions with a retainer, and fixing the lower honeycomb body under mild temperature conditions by brazing. A tandem metal carrier having a structure in which an upper honeycomb body and a lower honeycomb body are housed in an outer cylinder, and the upper honeycomb body having a small capacity is held between retainers fixed to the outer cylinder.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a tandem-type metal carrier used for purifying exhaust gas emitted from an automobile engine or the like.

[0002]

[Prior Art]

 As a catalyst carrier for purifying exhaust gas, a catalyst carrier in which a honeycomb body formed by using a heat-resistant metal foil is housed in a metal outer cylinder has been developed and has already been partially put into practical use. In recent years, in order to further improve the catalytic performance, a tandem carrier in which two honeycomb bodies are brazed and held in one outer cylinder is about to be used as a catalyst for automobiles. That is, in such a tandem carrier, as shown in an example in FIG. 4, the upper honeycomb body 2 and the lower honeycomb body 3 are rigidly joined at the brazing portions 4 and 5 in one flat outer cylinder 1. Has been done.

Generally, when a metal catalyst carrier is mounted in an exhaust gas system of an automobile engine, the carrier is repeatedly subjected to severe thermal cycles of rapid heating and rapid cooling from engine start to stop. As shown in FIG. 4, in the conventional tandem-type metal carrier, since the upper honeycomb body 2 has a small honeycomb volume, the temperature rises quickly and the temperature is high, so that the thermal expansion of the upper metal honeycomb body 2 and the outer cylinder 1 does not occur. The shrinkage increases, stress concentrates on the portion where the outer cylinder and the honeycomb body are joined, and peeling occurs, which is not preferable.

[0004]

[Problems to be solved by the device]

 When the honeycomb body has a long length, for example, as disclosed in Japanese Utility Model Laid-Open No. 62-194436, flat foil and corrugated foil are joined in a partial cross section, and honeycomb body and an outer cylinder are joined in part in the axial direction. A method has been proposed in which the stress is relaxed by bonding with a width of 10 mm and providing a non-bonding surface, but when using a honeycomb body with a short length of about 10 to 30 mm, such as a tandem carrier, There is a problem that stress concentration is likely to occur because the flat foil and the corrugated foil are joined or lapped at the partial cross-section joint and the joint between the honeycomb body and the outer cylinder. In order to solve the above conventional problems, the present invention provides a tandem-type metal carrier in which the upper metal honeycomb body and the outer cylinder are held by a stress relaxation structure in which the outer circumference of the honeycomb body and the inner circumference of the outer cylinder are not directly joined. To do.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the gist of the present invention is that two honeycomb bodies formed by stacking flat foils and corrugated foils made of heat-resistant metal and spirally winding or laminating them are made of heat-resistant metal. In a tandem metal carrier that is vertically housed and fixed in an outer cylinder, the upper honeycomb body is retained in the outer cylinder by a retainer, and the lower honeycomb body is fixed to the outer cylinder by brazing. On the carrier. That is, focusing on the fact that the length of the upper metal honeycomb body is as short as about 10 to 30 mm and having a low capacity and light weight, the upper metal honeycomb body is held by the retainer in the outer cylinder. Since it is lightweight, the contact pressure between the honeycomb body and the retainer is small, the edge buckling at the retainer part is reduced, and it is not destroyed. Incidentally, the joining in the honeycomb body may be a brazing structure or a welding structure.

The present invention will be described in detail below with reference to the drawings. FIG. 1 shows an example 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 numerals 6 and 7 denote retainers for holding the honeycomb body fixed to the inner circumference of the outer cylinder 1. The upper honeycomb body 2 is supported between the retainers 6 and 7, so that the upper honeycomb body 2 does not come into direct contact with the outer cylinder. I'm also good at it. Reference numeral 5 is a brazing portion between the lower honeycomb body 3 and the outer cylinder 1.

That is, the present invention has a problem that the upper honeycomb body 2 has a small capacity, so that thermal expansion and contraction with the outer cylinder 1 is large and peeling easily occurs. The upper honeycomb body 2 is retained by the retainers 6 and 7 for retaining the upper honeycomb body fixed to the outer cylinder 1 to form a stress relaxation structure, thereby eliminating the above-mentioned problem of peeling. The lower honeycomb body 3 and the outer cylinder may be joined by brazing 5 at a part in the axial direction.

FIG. 2 shows an example in which another retainer according to the present invention is used, in which the upper honeycomb body 2 housed in the outer cylinder 1 is the upper retainer 6 fixed to the outer cylinder 1. As shown in the cross-sectional view of FIG. 3 (cross-section taken along the line AA in FIG. 2), the upper honeycomb body 2 itself is not directly joined to the outer cylinder 1 by being held by the lower cross-shaped retainer 7 fixed to the outer cylinder 1. It has a stress relief structure. Reference numeral 5 indicates a joint (brazing) portion of the lower honeycomb body 3 to the outer cylinder 1 as in FIG.

As described above, in the tandem-type metal carrier, only the upper honeycomb body 2 which is susceptible to expansion and contraction due to heat is retained in the outer cylinder 1 by the retainers 6 and 7, and the lower honeycomb body 3 is brazed to the outer cylinder. The tandem metal carrier with less peeling is provided by fixing it to No. 1 and combining the joining forms.

[0010]

[Effect of the device]

 According to the tandem carrier of the present invention, peeling damage of the carrier between the outer cylinder and the honeycomb body can be prevented, and the effect is extremely large.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an example of a tandem type metal carrier of the present invention.

FIG. 2 is an explanatory view showing another example of the tandem-type metal carrier of the present invention.

3 is a diagram showing a cross section taken along the line AA of FIG.

FIG. 4 is an explanatory view showing a conventional tandem type metal carrier.

[Explanation of symbols]

 1: Outer cylinder 2: Upper honeycomb body 3: Lower honeycomb body 4,5: Brazing part 6, 7: Retainer

Claims (1)

[Scope of utility model registration request] 1. A tandem type in which two honeycomb bodies formed by stacking flat foil and corrugated foil made of a heat-resistant metal and spirally winding or stacking them are housed and fixed in an outer cylinder made of a heat-resistant metal. In the metal carrier, the upper honeycomb body is held in an outer cylinder by a retainer, and the lower honeycomb body is fixed to the outer cylinder by brazing, which is a tandem-type metal carrier.