JPS608112Y2 - monolith catalytic converter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a monolithic catalytic converter for purifying exhaust gas from an internal combustion engine.

A monolithic catalytic converter installed in the exhaust pipe of an internal combustion engine is generally configured to hold a monolithic catalyst within a casing consisting of a pair of shells divided in the axial direction via an elastic member such as ceramic fiber. .

(For example, see Japanese Utility Model Application Publication No. 54-61916.) This monolithic catalyst has a large number of vent holes formed in the axial direction in a honeycomb shape using a ceramic material. Although it purifies the exhaust gas passing through the ventilation hole, it is not possible to obtain high dimensional accuracy, especially in the radial direction, because it is molded from a ceramic material as described above.

In contrast, in conventional casings, a horizontally extending joining flange is provided around the periphery of each shell, the entire surface of each joining flange is joined, and then the ends of each joining flange are welded to achieve a certain content. Therefore, when the monolithic catalyst is attached to the casing via an elastic member, the dimensional accuracy of the elastic member itself is low, and the radial design dimensions of the casing do not match. There are many things.

For example, the monolithic catalyst and elastic member may be larger than the internal casing volume, creating a gap between opposing flanges of each shell.

For this reason, in the past, it was necessary to modify the dimensions of the casing each time a monolithic catalyst was installed, which not only resulted in low workability but also a tendency to produce defective products.

The present invention solves such conventional problems.1. The joint flanges of the pair of shells constituting the casing are each bent at right angles in the same direction with respect to the base extending parallel to the dividing plane of the casing. The object of the present invention is to provide a monolithic catalytic converter in which the ends of the joint flanges are overlapped and fixed by welding.

In this case, the overlapping parts of the ends of each joining flange are
The radial errors of monolithic catalysts and elastic members are absorbed by sliding during assembly.

In addition, since the end of the joint flange to be welded is perpendicular to the dividing plane, it can provide strong resistance against the force in the direction of dividing the casing, and the welded part can be connected to the monolithic catalyst via the base. Since the base is located far away from the base, it elastically absorbs the vibrations of the monolithic catalyst and reduces the effect of vibrations on the welded part.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below with reference to the drawings.

1 is a monolithic catalytic converter that is attached to the exhaust pipe of an internal combustion engine, and includes a pair of axially divided shells 2,
An elliptical columnar monolithic catalyst 6 is held inside a casing 3 made up of two parts via an elastic member 5, and mounting flanges 7.7 connected to an exhaust pipe are fixed to both ends of the casing 3.

The shells 2, 2 are formed by press molding a stainless steel material, and are provided with joining flanges 8, 8 on their peripheries.

The joining flange 8.8 has a base portion 8a*8a that is parallel to the dividing surface of the casing 3, and its ends 8b, 8b are bent in the same direction and perpendicular to the dividing surface. The casing 3 is constructed by overlapping the casings 8b and welding them together.

On the other hand, the monolithic catalyst 6 has a large number of vent holes 10 formed in a honeycomb shape in the axial direction using a ceramic material.The inner surface of the vent holes 10 is coated with alumina, and a platinum-based catalyst is further coated on the alumina. is coated.

Furthermore, the elastic member 5 interposed between the monolithic catalyst 6 and the casing 3 is made of ceramic fiber glass cotton, asbestos, steel wool, or the like.

In the monolithic catalytic converter 1, the surface of a monolithic catalyst 6 is covered with an elastic member 5, and this is housed in shells 2, 2, and while the elastic member 5 is compressed by both shells 2, 2, a joint flange is formed. The ends 8b, 8b of 8, 8 are overlapped and fixed by welding to assemble.

In this assembled state, the base 8 of the joining flanges 8, 8
A and Ba face each other with a slight gap 11 between them.

That is, if the radial dimension of the monolithic catalyst 6 or the elastic member 5 becomes larger than the designed dimension due to a manufacturing error, the overlapping ends 8 of the joining flanges 8, 8
By sliding the ends 8b and 8b to widen the gap 11, dimensional errors are allowed. Conversely, if the radial dimension of the monolithic catalyst 6 or the elastic member 5 becomes smaller than the designed dimension, the end portion 8b , 8b to narrow the gap 11 to allow for dimensional errors.

Therefore, according to the present invention, it is possible to tolerate dimensional errors in the radial direction of the monolithic catalyst and the elastic member during assembly by adjusting the overlapping amount of the end portions of the joining flanges.
In addition, since the welded part at the end of the joining flange is perpendicular to the dividing plane of the casing, the resistance to force in the direction perpendicular to the dividing plane increases, and the base of the joining flange is between the monolithic catalyst and the welded part. The ability of each shell to elastically absorb the independent vibrations associated with the vibrations of the monolithic catalyst, combined with the ability of the base to flex and allow the movement of the shells to spread in the direction perpendicular to the dividing plane, makes it possible for the casing to Increased holding power.

Furthermore, the present invention has the effect that even if the elastic member interposed between the monolithic catalyst and the casing deteriorates due to heat, the base of the joining flange elastically holds the monolithic catalyst in place of the elastic member.

[Brief explanation of drawings]

The drawings illustrate embodiments of the present invention, in which FIG. 1 is a plan view showing a monolithic catalytic converter partially in section, and FIG. 2 is a sectional view taken along line AA in FIG. 1... Monolith catalytic converter, 2...
・Shell, 3...Casing, 5...
Elastic member, 6... Monolith type catalyst, 8...
...Joining flange, 8b... End.

Claims (1)

[Scope of utility model registration request] In a monolithic catalytic converter in which a monolithic catalyst is held within a casing consisting of a pair of shells divided in the axial direction via an elastic member, a joining flange is formed at the periphery of each shell, and the multi-jointed flange is Each consists of a base extending parallel to the dividing plane and an end bent at right angles in the same direction with respect to the base, while the ends of the multi-joint flange are overlapped and welded together. A monolithic catalytic converter characterized by a fixed structure.