JPH0437226Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

The present invention relates to a catalytic converter installed in a vehicle exhaust system, and particularly to the structure of a casing that holds a catalyst carrier.

[Conventional technology]

Conventionally known catalytic converters include a casing that holds a catalyst carrier inside, and a pair of shell members that are flanged together on a surface along the flow direction of exhaust gas (see Japanese Utility Model Application No. 56-85014). ).

[Problem that the invention attempts to solve]

By the way, according to the above-mentioned conventional example, the pair of shell members each have a joining flange covering the entire surface, and since the structure is such that both flanges are joined, the welding structure is edge welding. Therefore, there was a problem that the strength of the welded part at high temperatures was low, and thermal damage was likely to occur in the parts that were in direct contact with the high-temperature exhaust gas. However, if a pair of shell members is provided with a joint flange only on one side, or without a joint flange on either side, fillet welding becomes possible and thermal strength can be improved. However, in this case, since there is no joining flange, there arise problems such as difficulty in canning, deterioration of productivity, or deterioration of the accuracy of the press-formed shape. SUMMARY OF THE INVENTION An object of the present invention is to provide a catalytic converter in which the joining structure of a pair of shell members does not reduce productivity and can improve thermal strength.

[Means to solve the problem]

For this purpose, the present invention includes a pair of shell members that connect a casing having an inlet and an outlet for exhaust gas as described above and holding a catalyst carrier therein at a surface along the flow direction of the exhaust gas. In the configured catalytic converter, the joint part of the shell member has an edge welding structure where both flanges are joined at the part facing the circumferential surface of the catalyst carrier, and a fillet welding structure with one flange at other parts. .

[Effect]

By such a means, each of the pair of shell members has a flange, so that it is easy to handle during the production process, and by bringing both flanges together, canning is facilitated and sufficient dimensional accuracy can be ensured. The structure of the casing is a fillet welded structure with one flange near the exhaust gas inlet and outlet where the exhaust gas comes into direct contact, and in the edge welded structure where both flanges are joined, the exhaust gas passes through the catalyst carrier and does not come into direct contact. , thermal strength is also sufficient.

【Example】

Hereinafter, one embodiment of the present invention will be specifically described based on the drawings. In FIGS. 1 and 5, reference numeral 1 designates a monolithic catalytic converter, which is housed in a casing having two exhaust gas inlets 11 and one exhaust gas outlet 12, as shown in FIGS. 2 and 3. A monolithic catalyst carrier 13 as shown is held via an elastic member 14. The two exhaust gas inlets 11 are connected to the exhaust gas front pipes 31 and 32 on the engine 2 side, and the exhaust rear pipe 3 is connected to one exhaust gas outlet 12.
3, the catalytic converter 1 is interposed in the middle of the exhaust pipe 3. As shown in FIGS. 2 and 3, the casing of the catalytic converter 1 is composed of a pair of shell members 15 and 16 that are joined at a plane along the flow direction of exhaust gas. Here, a joint flange 17 is formed on the lower shell member 16 over the entire joint surface, whereas
A joining flange 18 is formed on the upper shell member 15 only at a portion facing the circumferential surface of the catalyst carrier 13, that is, a portion that comes into contact with the elastic member 14. The upper and lower shell members 15 and 16 are joined by edge welding by overlapping the joining flanges 17 and 18 (see Fig. 2).
8, the edge 19 of the upper shell member 15
is inserted into the inside of the joining flange 17 of the lower shell member 16 and joined by fillet welding (see FIGS. 3 and 4). In such a configuration, since the pair of shell members 15 and 16 constituting the casing each have the joining flanges 18 and 17, they are easy to handle in the production process, and canning is facilitated by overlapping both the joining flanges 18 and 17. At the same time, dimensional accuracy is also improved. Then, a pair of such shell members 15, 1
In the casing consisting of the joint structure of No. 6, the edge-welded structure portion formed by the joint flanges 18 and 17 does not come into direct contact with high-temperature exhaust gas due to the presence of the elastic member 14. The front and rear portions of the catalyst carrier 13 in the vicinity of the inlet 11 and the outlet 12 have a fillet welded structure and therefore have high thermal strength and are unlikely to suffer thermal damage.

[Effect of the idea]

As explained above, according to the present invention, since each of the pair of shell members has a flange, it is easy to handle during the production process, and by aligning both flanges, canning is facilitated and sufficient dimensional accuracy can be ensured, thereby preventing deterioration of productivity. Despite this, the area near the exhaust gas inlet and outlet where exhaust gas comes into direct contact has a fillet welded structure with one flange, which provides sufficient strength against thermal damage.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a catalytic converter according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line -- in FIG.
Figure 3 is a sectional view taken along the - line in Figure 1, and Figure 4 is a cross-sectional view of Figure 1.
The arrow direction view in the figure, FIG. 5, is a layout configuration diagram of the catalytic converter in the exhaust system. DESCRIPTION OF SYMBOLS 1...Catalytic converter, 11...Exhaust gas inlet, 12...Exhaust gas outlet, 13...Monolith catalyst carrier, 14...Elastic member, 15...Upper shell member, 16...Lower shell member, 17, 18...
Joint flange, 19... edge, 2... engine,
3...exhaust pipe, 31, 32...exhaust front pipe, 33...exhaust rear pipe.

Claims (1)

[Scope of utility model registration request] A catalytic converter comprising a pair of shell members joining a casing having an inlet and an outlet for exhaust gas and holding a catalyst carrier therein at a surface along the flow direction of the exhaust gas, the joint portion of the shell members The catalytic converter is characterized in that the portion facing the circumferential surface of the catalyst carrier has an edge-welded structure with both flanges joined together, and the other portion has a fillet-welded structure with one flange.