JPS6016728Y2 - Catalytic converter for exhaust gas purification - Google Patents

Description

[Detailed Description of the Invention] A. Purpose of the Invention (1) Industrial Application Field The present invention relates to a catalytic converter for purifying exhaust gas that is installed in the exhaust pipe of a vehicle internal combustion engine.

(2) Conventional technology Conventionally, as shown in Fig. 3, a vehicle catalytic converter equipped with a monolithic catalyst carrier has a casing main body 01 formed by a hollow cylindrical body having the same diameter over the entire length, and a wire mesh A catalyst carrier 08 whose outer periphery is covered with a cushion body 09 is inserted, and the outer peripheral surface of the catalyst carrier 08 is held in the casing main body 01 via the cushion body 09, while the end face of the catalyst carrier 08 is covered with the end face cushion body 01.
It was configured to be held by a holding fitting 011 that is fixed to the casing main body 01 via the casing body 01.

(3) Problems to be solved by the invention In the conventional catalytic converter, the catalyst carrier 08 must be inserted into the casing main body 01 with strong pressure in the axial direction while compressing the cushion body 09 on its outer periphery in the radial direction. Therefore, the work of inserting and assembling the catalyst carrier 08 is not easy.
The cushion body 09 made of wire mesh has a high density at the insertion rear end where the insertion resistance of the inner surface of the casing main body 01 is strong, and the surface pressure against the catalyst carrier 08 increases, so that when the catalytic converter is subjected to vibration or impact, , local stress concentration may occur at the inserted rear end of the catalyst carrier 08, which may damage or break the fragile catalyst carrier 08.

Furthermore, if the catalytic converter is subjected to repeated vibrations or shocks after the catalyst carrier 08 is assembled, the dense insertion rear end of the cushion body 09 will gradually extend outward in the axial direction and come into contact with the end face cushion body 010. , the end face cushion 010 is pressed and deformed outward, causing play in the axial direction between it and the catalyst carrier 08, which causes damage and breakage of the catalyst carrier 08.

In addition, as a means to eliminate such problems, the cushion body 0
It is conceivable to provide a sufficient axial gap in advance between the inserted rear end of C.9 and the end cushion body 010 to avoid collision between them, but if this is done, the total length of the casing C' becomes longer. This causes other inconveniences such as:

The main object of the present invention is to provide a catalytic converter for exhaust gas purification that eliminates all of the above-mentioned problems of the conventional ones.

B. Structure of the device (1) Means for solving the problem The device has a main body of a hollow cylindrical casing.
A catalyst for exhaust gas purification, wherein the outer peripheral surface of a monolithic catalyst carrier is held via a wire mesh cushion body, and the end face of the catalyst carrier is held via the end face cushion body by a holding fitting fixed to the main body of the casing. The converter is characterized in that a large-diameter end portion is formed at an end portion of the main body of the casing via an inclined step portion.

(2) Function The inclined stepped portion of the casing body gradually compresses the cushion body inserted into the large diameter end of the casing body when assembling the catalyst carrier in the radial direction, and then guides it smoothly into the center of the casing body. can.

In addition, the large diameter end portion of the casing can alleviate the tendency toward high density at the insertion rear end portion of the cushion body, and prevent stress concentration at the end portion of the catalyst carrier with which the insertion rear end portion comes into contact.

Furthermore, it is possible to allow the insertion rear end of the cushion body to expand in the radial direction, thereby preventing it from extending outward in the axial direction and thereby preventing interference with the end face cushion body.

(3) Example Hereinafter, the first example of the present invention will be explained with reference to FIG. 1. The casing C of the catalytic converter has a hollow cylindrical shape with a large-diameter end 4 formed at both ends via an inclined step 5. It consists of a casing main body 1 and a pair of frustoconical casing terminals 2 and 3 welded to the large diameter end 4, with an inlet 6 at one of the casing terminals 2 and 3 and an outlet at the other. The lower is opened.

Inside the casing main body 1, the casing terminal 2,
Before welding 3, the outer periphery was covered from one open end with a cushion body 9 made of wire mesh.
A monolithic catalyst carrier 8 is inserted, and this catalyst carrier 8 is supported in the center of the casing body 1 via the moderately compressed cushion body 9, and both ends of the cushion body 9 are attached to the large diameter end of the casing body 1. Let's face part 4.

Both end faces of the catalyst carrier 8 are held by holding fittings 11 fixed to the casing main body 1 via an end face cushion body 10 so as not to move in the axial direction.

The holding fitting 11 has a U-shaped cross section, and its outer flange piece 12 is welded to the inner surface of the large diameter end 4 toward the inside of the casing main body 1 so as to surround the end cushion body 10. and the outer flange piece 12
The tip extends inward from the inner end surface of the end face cushion body 10.

By the way, the catalyst carrier 8 has a cushion body 9 on its outer periphery.
It is inserted into the casing main body 1 in a state covered with the casing main body 1 and assembled at a predetermined position of the casing main body 1,
The catalyst carrier 8 is inserted into the casing main body 1 from its large diameter end 4, especially together with the cushion body 9 on its outer periphery, and is incorporated into the casing main body 1 while being gradually compressed by the inclined step portion 5. This makes the installation work extremely easy.

In addition, the wire mesh cushion body 9 that covers the outer periphery of the catalyst carrier 8 is inserted into the casing main body 1 while being compressed together with the catalyst carrier 8, so that the insertion resistance of the inner surface of the casing main body 1 is especially strong. There is a tendency for the rear end to become denser, but the casing is mainly 1
has a large-diameter end 4, so by having the insertion rear end of the cushion body 9 face the large-diameter end 4, the increase in density is alleviated and stress concentration in the catalyst carrier 8 is prevented, and the stress is reduced. Damage and breakage of the catalyst carrier 8 due to concentration can be prevented.

Further, although the cushion body 9 is mainly compressed in the radial direction, since the end portion of the cushion body 9 faces the large diameter end portion 4 of the casing main body 1, expansion in the radial direction is allowed, and vibrations of the catalytic converter and The expansion of the cushion body 9 in the axial direction is reduced as much as possible due to rocking, etc., and as a result, the outer flange piece 12 of the holding fitting 11 is welded to the casing main body 1 toward the catalyst carrier 8 side as described above. This makes it possible to shorten the overall length of the casing C, and prevents the cushion body 9 from elongating in the axial direction and causing play in the axial direction with the catalyst carrier 8. Damage or breakage of the catalyst carrier 8 is also prevented.

Furthermore, since the monolithic catalyst carrier 8 is generally made of ceramic or the like, it has a large tolerance in outer diameter (for example, +1.6 mm).
~-2.67rr! n) Although there is some variation in the outer diameter, the casing main body 1 can be produced by simply changing only the inner diameter dimension of the central part and preparing a plurality of types having the same inner diameter dimension of the large diameter end part 4. Other parts such as the casing terminals 2 and 3 and the holding fittings 11 can be made common without making any dimensional changes, so that the above-mentioned variations can be accommodated, and costs can be reduced.

FIG. 2 shows a second embodiment of the invention.

In this second embodiment, the cross-sectional shape of the holding fitting 11 that suppresses the axial movement of the catalyst carrier 8 is formed into a substantially Z-shape, and the outer flange piece 12 is directed toward the outside of the casing main body 1 so that the large diameter end 4, and it goes without saying that it has the same effects as those of the first embodiment.

Effects of the C Design As described above, according to the present invention, when the catalyst carrier is inserted into the casing body, the inclined stepped portion of the casing body gradually compresses the cushion body on the outer periphery of the catalyst carrier in the radial direction. Since the catalyst carrier can be guided smoothly into the central portion, the work of assembling the catalyst carrier can be easily and easily performed.

In addition, the large diameter end of the casing can reduce the density increase at the insertion rear end of the cushion body, so stress concentration does not occur at the end of the catalyst carrier that is in contact with the insertion rear end.
Damage and breakage of the catalyst carrier caused by this can be prevented.

Moreover, since the large diameter end of the casing can allow the insertion rear end of the cushion body to expand in the radial direction, expansion in the axial direction of the insertion rear end due to vibrations of the catalytic converter can be effectively suppressed. It is possible to prevent interference between the end face cushion body and the end face cushion body, and therefore, the axial play of the catalyst carrier can be accurately suppressed by the end face cushion body. The catalytic converter can be disposed as close as possible to the insertion rear end of the catalytic converter, thereby making it possible to make the catalytic converter more compact in the axial direction.

The main body of the casing of the catalytic converter of the present invention has a relatively simple structure with only a large-diameter end formed through an inclined step at the end, so compared to the main body of the casing of the conventional catalytic converter. There is no obvious increase in costs.

[Brief explanation of drawings]

FIG. 1 is a partially longitudinal side view of a first embodiment of the catalytic converter of the present invention, FIG. 2 is a partially longitudinal side view of the second embodiment, and FIG. 3 is a longitudinal side view of a conventional catalytic converter. . C...Casing, 1...Casing main body, 4...Large end portion, 8...Catalyst carrier, 9...Cushion body , 10... End cushion body, 11... Holding metal fitting, 12...
...outer flange piece.

Claims (1)

[Scope of utility model registration request] The outer peripheral surface of a monolithic catalyst carrier is held within the hollow cylindrical casing main body of the casing via a wire mesh cushion body, and the end face of the catalyst carrier is held via the end face cushion body by a holding fitting fixed to the casing main body. In the catalytic converter for exhaust gas purification, the catalytic converter for exhaust gas purification is held by a casing main body, and a large diameter end portion is formed at the end portion of the main body of the casing via an inclined stepped portion.