CONNECTING STRUCTURE OF EXHAUST SYSTEM MEMBER AND INSERTION MEMBER

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A connecting structure of an exhaust system member and an insertion member includes a first divided part 44 and a second divided part 45 each formed like a semi-circular cylinder. The first and second divided parts 44 and 45 are coupled like a barrel so that projecting portions 45c are engaged with inner sides of bulge portions 44c, respectively, and end portions of the first and second divided parts 44 and 45 are contacted to form a circular cross section, the both edge portions of the first and second divided parts 44 and 45 being fixed with each other by welding X1 to form the exhaust system member (diffuser 43). After the insertion member (catalyst carrier case 41) is inserted in the end portion 43a of the diffuser 43a, the end portion and an outer circumferential surface of the catalyst carrier case 41 are fixed by welding X2 all along the outer circumferential surface.

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Description
TECHNICAL FIELD

The present invention relates to a connecting structure of an exhaust system member and an insertion member, both of which are used in an exhaust system connected with an engine of a motor vehicle or the likes.

BACKGROUND OF THE INVENTION

Japanese Patent Applications Laid-Open Publication No. 2004-92512 and No. 09-329019 disclose technology on conventional connecting structures of an exhaust system member and an insertion member. As shown in FIG. 6, both edge portions of a divided part 011 formed like a semi-circular cylinder is coupled with inner sides of bulge portions 012a of a divided part 012 formed in a semi-circular cylinder, so that the bulge portions 012a are formed to expand in an outward direction to entirely form a substantially circular cross section. Then the both edge portions of the divided parts 011 and 012 are fixed with each other by welding to form an exhaust system member 010, and a not-shown insertion member is inserted into an end portion of the exhaust system member 010. Then the end portion of the exhaust system member 010 and an outer circumferential surface of the insertion member are fixed with each other by welding all around the outer circumferential surface.

DISCLOSURE OF THE INVENTION Problem(s) to be Solved by the Invention

The above-described conventional inventions, however, have problems in that a gap O, shown in FIG. 6, is generated between the end portion of the exhaust system member 010 and the insertion member, so that, in a case where they are welded with each other all along the outer circumferential surface, a lot amount of welding material is needed to close the gap O, and it takes a relatively long time to weld them.

The present invention is made in order to solve the above-described problems, and it is an object thereof is to provide a connecting structure of an exhaust system member and an insertion member where a lot of amount of welding material is not needed and they can be welded with each other in a relatively little time in a case where an end portion of the exhaust system member, which is formed by coupling a first divided part and a second divided part with each other, and an outer circumferential surface of the insertion member are welded with each other all along the outer circumferential surface.

Means for Solving the Problems

According to a first aspect of the present invention there is provided a connecting structure of an exhaust system member and an insertion member, where the exhaust system member includes a first divided part and a second divided part. The first divided part is formed like a semi-circular cylinder to have bulge portions respectively projecting in an outward direction at both edge portions thereof except end portions thereof; and the second divided part is formed like a semi-circular cylinder to have projecting portions respectively engageable with inner sides of the bulge portions of the first divided part at both edge portions except end portions thereof. The first divided part and the second divided part are coupled with each other to form a barrel-like shape so that the projecting portions are engaged with the inner sides of the bulge portions, respectively. The end portions of the first divided part and the second divided part are contacted with each other to form a circular cross section, respectively, then the both edge portions of the first divided part and the second divided part being welded with each other. The end portions and an outer circumferential surface of the insertion member are welded with each other all along the outer circumferential surface.

EFFECT OF THE INVENTION

In the connecting structure of the exhaust system member and the insertion member including the first divided part and the second divided part. The first divided part is formed like the semi-circular cylinder to have the bulge portions respectively projecting in the outward direction at the both edge portions thereof except the end portions thereof; and the second divided part is formed like the semi-circular cylinder to have the projecting portions respectively engageable with the inner sides of the bulge portions of the first divided part at the both edge portions except the end portions thereof. The first divided part and the second divided part are coupled with each other to form the barrel-like shape so that the projecting portions are engaged with the inner sides of the bulge portions, respectively. The end portions of the first divided part and the second divided part are contacted with each other to form the circular cross section, respectively, then the both edge portions of the first divided part and the second divided part being welded with each other. The end portions and the outer circumferential surface of the insertion member are welded with each other all along the outer circumferential surface. As a result, the end portion of the exhaust system member and the insertion member can have the circular cross section without a step, thereby no gap being formed therebetween. Therefore, in a case where the end portions of the exhaust system member, including the first divided part and the second divided part, and the outer surface of the insertion are joined with each other all along the outer circumferential surface by the welding, they can be welded with each other with a relatively little amount of welding material and in a relatively little time.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects, features and advantages of the present invention will become apparent as the description proceeds when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a diagram illustrating an exhaust system that is provided with a connecting structure of an exhaust system member and an insertion member of a first embodiment according to the present invention;

FIG. 2 is an exploded perspective view showing a diffuser, which corresponds to the exhaust system member of the first embodiment;

FIG. 3 is a perspective view showing the diffuser of the first embodiment;

FIG. 4 is a view showing fixation between the diffuser of a catalytic converter and a catalyst carrier case of the first embodiment;

FIG. 5 is a view showing the fixation between the diffuser of the catalytic converter and the catalyst carrier case of the first embodiment; and

FIG. 6 is a view showing a conventional connecting structure of an exhaust system member and an insertion member.

 DESCRIPTION OF REFERENCE NUMBERS

X1, X2 welding

1 engine

2 exhaust manifold

3, 5, 8 flange

4 catalytic converter

6, 9 connecting pipe

7 sub-muffle

10 main muffler

41 catalyst carrier case

41a catalyst carrier

42, 43 diffuser

43a end portion (of the diffuser)

44 first divided part

44a, 44b end portion (of the first divided part)

44c bulge portion

45 second divided part

45a, 45b end portion (of the second divided part)

45c bulge portion

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment according to the present invention will be described with reference to the accompanying drawings.

First Embodiment

Hereinafter, a first embodiment will be described.

Incidentally, a case will be described, in which an exhaust system member is a diffuser of a catalytic converter and an insertion member is a catalyst carrier case that contains a catalyst carrier.

FIG. 1 is a diagram illustrating an exhaust system that is provided with a connecting structure of the exhaust system member and the insertion member of the first embodiment, FIG. 2 is an exploded perspective view showing the diffuser of the first embodiment, FIG. 3 is a perspective view showing the same, and FIGS. 4 and 5 are views illustrating fixation between the diffuser of the catalytic converter and the catalyst converter carrier of the first embodiment.

First, an entire construction of the first embodiment will be described. As shown in FIG. 1, in an exhaust system that is provided with a connecting structure of an exhaust system member and an insertion member of the fist embodiment, the system includes an engine 1, a catalytic converter 4 that is connected with the engine 1 through an exhaust manifold 2 and a flange 3, a sub-muffler 7 that is connected with the catalytic converter 4 through a flange 5 and a connecting pipe 6, and a main muffler 10 that is connected with the sub-muffler 7 through a flange 8 and a connecting pipe 9.

The catalytic converter 4 is composed of a catalyst carrier case 41 that is made of metal material to be formed like a cylinder, and diffusers 42 and 43 that are made of metal material to be formed like a funnel, the diffusers 44 and 45 being connected with both end portions of the catalyst carrier case 41. The catalyst carrier case 41 corresponds to an insertion member of the present invention, and each of the diffusers 42 and 43 corresponds to an exhaust system member of the present invention.

Further, a catalyst carrier 51a, shown in FIG. 4, is contained in the catalyst carrier case 41. The catalyst carrier 41a employs a metal catalyst carrier that is formed like a circular cylinder formed by a metal corrugated plate and a metal flat plate, which are not shown, being multiply rolled together with each other, or a ceramic catalyst carrier that is made of porous ceramic material and formed like a circular cylinder. It carries catalyst components such as platinum (Pt) on surfaces of exhaust passages that are formed to penetrate the catalyst carrier in a longitudinal direction thereof. The catalyst components convert harmful components such as nitroxide (NOx) and carbon monoxide (CO) that are contained in exhaust gas flowing through the catalyst carrier case 41 into unharmful components to be discharged as carbon dioxide (CO2), water (H2O) and others, by catalysis thereof. Incidentally, in a case of using the metal catalyst carrier, the catalyst carrier case 41 is fixed by brazing to the catalyst carrier 41a where a corrugated plate and a flat plate are fixed with each other by diffusion bonding in the catalyst carrier case 41. In a case of using the ceramic catalyst carrier, the catalyst carrier 41a is press-fitted into and fixed to the catalyst carrier case 41 through a mat.

Hereinafter, connecting structures between the catalyst carrier case 41 and the diffuser 42 and between the catalyst carrier case 41 and the diffuser 43 are similar to each other, and accordingly only the connecting structure of the catalyst carrier case 41 and the diffuser 43 will be described in detail.

As shown in FIG. 2, the diffuser 43 is composed of a first divided part 44 and a second divided part 45, where the first divided part 44 is formed like a semi-circular cylinder to have bulge portions 44c that expand in an outward direction at both edge portions thereof except both end portions 44a and 44b thereof, and the second divided part 45 is formed like a semi-circular cylinder to have projecting portion 44c that are capable of engaging with inner sides of the corresponding bulge portions 44c of the first divided part 44 except both end portions 45a and 45b thereof.

As shown in FIG. 3, the first divided part 44 and the second divided part 45 are coupled with each other like a barrel to entirely have a circular cross section by the projecting portions 45c of the second divided part 45 being engaged with the inner sides of the corresponding bulge portions 44c of the first divided part 44 and also the both end portions of the first and second divided portions 44 and 45 being contacted with each other. Then, the both edge portions of the first and second divided parts 44 and 45 are fixed to each other by welding X1, which are indicated by a thick line, to form the diffuser 43.

In this welding process, the welding X1 can be performed along a straight-like welding line to fix the both edge portions of the first and second divided parts 44 and 45, and therefore good weldability thereof can be obtained.

Next, as shown in FIG. 4, the catalyst carrier case 41 is inserted a predetermined depth into an exhaust gas upstream side end portion 43a of the diffuser 43, and then, as shown in FIG. 5, the exhaust gas upstream side end portion 43a and an outer circumferential surface of the end portion of the catalyst carrier case 41 are fixed with each other by welding X2 all along the end portion, so that the diffuser 43 and the catalyst carrier case 41 are joined with each other.

Herein, in the above-described conventional inventions, the bulge portions and the projecting portions are formed to extend up to the both end portions of the diffuser. As a result, gaps are formed between the end portion of the diffuser and the insertion member, which requires a lot of welding material to close the gaps. In addition, this closing work takes a relatively long time.

On the contrary, in the first embodiment, as described above, the both end portions of the first and second divided parts 44 and 45 are contacted with each other to entirely form the circular cross section, so that no gap is formed between the exhaust gas upstream side end portion of the diffuser 43 and the catalyst carrier case 41. Therefore, it prevents sputter of the welding from coming in the diffuser 43. In addition, the first and second divided parts 44 and 45 are welded with each other with a little amount of the welding X2 and in a relatively short time.

Further, in a state where an exhaust gas downstream side end portion 43b of the diffuser 43 is provided with a flange 5 at its outer side, a peripheral portion of a through hole formed in the flange 5 is fixed to an outer circumferential surface of the diffuser 43 by not-shown welding all along them.

Incidentally, the catalyst carrier case 41 and the diffuser 42, and the diffuser 42 and the flange 3 are joined with each other similarly to the above-described joining.

Next, the effects of the first embodiment will be described.

As explained above, the connecting structure of the exhaust system member and the insertion member of the first embodiment includes first divided part 44 that is formed like the semi-circular cylinder to have the bulge portions 44c respectively projecting in the outward direction at the both edge portions thereof except end portions 44a and 44b thereof; and the second divided part 45 that is formed like the semi-circular cylinder to have the projecting portions 45c respectively engageable with the inner sides of the bulge portions 44c of the first divided part 44 at the both edge portions except end portions 45a and 45b thereof. The first divided part 44 and the second divided part 45 are coupled with each other to form the barrel-like lo shape so that the projecting portions 44c are engaged with the inner sides of the bulge portions 44c, respectively The end portions of the first divided part 44 and the second divided part 45 are contacted with each other to form the circular cross section, and the both edge portions of the first divided part 44 and the second divided part 45 are welded with each other. is The end portions and the outer circumferential surface of the catalyst carrier case 41 are welded with each other all along the outer circumferential surface. Therefore, in a case where the end portions of the diffuser 43, which consists of the first divided part 44 and the second divided part 45, and the outer surface of the catalyst carrier case 41 are joined with each other all along the outer circumferential surface by the welding X2, they can be welded with each other with the relatively little amount of the welding material and in a relatively little time.

While the embodiment has been explained, the present invention is not limited to the above-described embodiment, and its design changes and modifications are contained in the present invention as long as they do not depart from the subject matter of the present invention.

For example, the exhaust system member is not limited to the diffuser 43 of the catalytic converter 4, and using parts such as ones connecting with an exhaust pipe can obtain the similar effects.

Claims

1. A connecting structure of an exhaust system member and an insertion member comprising:

a first divided part that is formed like a semi-circular cylinder to have bulge portions respectively projecting in an outward direction at both edge portions thereof except end portions thereof; and
a second divided part that is formed like a semi-circular cylinder to have projecting portions respectively engageable with inner sides of the bulge portions of the first divided part at both edge portions except end portions thereof, wherein
the first divided part and the second divided part are coupled with each other to form a barrel-like shape so that the projecting portions are engaged with the inner sides of the bulge portions, respectively;
the end portions of the first divided part and the second divided part are contacted with each other to form a circular cross section, wherein
the both edge portions of the first divided part and the second divided part are welded with each other; and wherein
the end portions and an outer circumferential surface of the insertion member are welded with each other all along the outer circumferential surface.

2. The connecting structure of the exhaust system member and the insertion member according to claim 1, wherein

the exhaust system member is a diffuser of a catalytic converter, and wherein
the insertion member is a catalyst converter case that contains a catalyst converter.
Patent History
Publication number: 20100005789
Type: Application
Filed: Nov 1, 2007
Publication Date: Jan 14, 2010
Applicant:
Inventor: Shunsuke Moritsugu (Saitama)
Application Number: 12/439,417
Classifications
Current U.S. Class: Using A Catalyst (60/299); Internal Combustion Engine With Treatment Or Handling Of Exhaust Gas (60/272)
International Classification: F01N 3/28 (20060101); F01N 7/18 (20060101);