Construction of coupling exhaust pipes of vehicle
An opening edge of an upstream-side exhaust pipe and an opening edge of a downstream-side exhaust pipe opposed to the opening edge of the upstream-side exhaust pipe are bent radially outward and thereafter radially inward by molding to form a circumference of the upstream-side exhaust pipe and a circumference of the downstream-side exhaust pipe as a flange portion respectively. After both flange portions are butted to each other through a gasket disposed therebetween, they are mechanically coupled to each other with a bolt and a nut.
Latest Nakagawa Sangyo Co., Ltd. Patents:
1. Field of the Invention
The present invention relates to a construction of coupling exhaust pipes of a vehicle to each other and more particularly to a coupling construction, having a smaller number of parts, which is capable of coupling exhaust pipes to each other without welding the exhaust pipes to each other.
2. Description of the Related Art
In the construction of coupling exhaust pipes to each other disclosed in Japanese Patent Application Laid-Open No. 2002-227643, after the clamping fitting is mounted on one of the exhaust pipes, and another clamping fitting is mounted on the other exhaust pipe fitted in the one exhaust pipe, both exhaust pipes are coupled to each other by tightening the clamping fittings with a bolt and a nut.
In the above-described conventional constructions of coupling exhaust pipes to each other, it is necessary to weld the coupling flanges 61, 62 of the first conventional example to the periphery of the end of the exhaust pipes 1, 2 respectively. It is also necessary to weld the locking rings 71, 72 of the second conventional example to the periphery of the end of the exhaust pipes 1, 2 respectively. Therefore each of the above-described constructions has a problem that a stress concentrates on the welded portion and thus the exhaust pipes 1, 2 are liable to crack owing to vibrations of a vehicle body and that time and labor are required in a welding process. The first conventional example has another problem that when a face pressure is increased to prevent leak of a gas from the gasket 63, it is necessary to set the thickness of the coupling flanges 61 and 62 to as thick as 10 to 12 mm. Hence the weight and cost of the coupling construction increase. The second conventional example has another problem that many component parts are used for the coupling construction.
SUMMARY OF THE INVENTIONThe present invention has been made to solve the above-described problems. Therefore it is an object of the present invention to provide a construction of coupling exhaust pipes of a vehicle which does not have a possibility of breakage, even though the vehicle body vibrates, does not cause an increase in the weight and cost thereof, and in the number of component parts, and can be manufactured easily.
To achieve the above-described object, in the first invention, in a construction of coupling exhaust pipes of a vehicle, an opening edge of an upstream-side exhaust pipe and an opening edge of a downstream-side exhaust pipe opposed to the opening edge of the upstream-side exhaust pipe are bent radially outward to form a circumference of the upstream-side exhaust pipe and a circumference of the downstream-side exhaust pipe as a flange portion respectively; and after the both flange portions are butted to each other through a sealing member disposed between the both flange portions, the both flange portions are mechanically coupled to each other by means of coupling members.
In the first invention, the coupling construction does not have a portion to be welded unlike the conventional coupling construction. Further the coupling construction can be prevented from cracking because a stress does not concentrate on a welded portion. In addition, time and labor can be saved because it is unnecessary to perform a welding process. Further because it is unnecessary to use thick coupling flanges to obtain a face pressure necessary for preventing leak of gas, it is possible to prevent an increase in the weight of the coupling construction and the cost thereof. Furthermore because the flange portions are formed by bending the opening edge of the upstream-side exhaust pipe and that of the downstream-side exhaust pipe, it is possible to use a smaller number of parts for the coupling construction of the present invention than for the conventional coupling construction in which the coupling flanges are welded to the upstream-side exhaust pipe and the downstream-side exhaust pipe respectively.
In the second invention, in a construction of coupling exhaust pipes of a vehicle, an opening edge of an upstream-side exhaust pipe and an opening edge of a downstream-side exhaust pipe opposed to the opening edge of the upstream-side exhaust pipe are bent radially outward to form a circumference of the upstream-side exhaust pipe and a circumference of the downstream-side exhaust pipe as a flange portion respectively; and after the both flange portions are butted to each other through a sealing member disposed between the both flange portions, the both flange portions are coupled to each other by means of a pair of sandwiching members which sandwiches the both flange portions therebetween at an outer side of each of the flange portions in a direction in which the both opening edges are opposed to each other. The second invention provides an effect similar to that of the first embodiment.
In the third invention, a flange portion is formed by crushing in a longitudinal direction of a pipe at least one of adjacent bulged portions formed by bulging the pipe radially outward at an intermediate position of the pipe spaced at a predetermined interval from an opening of the pipe in such a way as to superimpose both slopes of each of the sectionally mountain-shaped bulged portions each other. In the third invention, the pipe at the intermediate position thereof spaced at the predetermined interval from the opening is projected. Therefore the wall of the pipe between the opening and the base of the mountain at the side of the opening is supplied to the bulged portion owing to the increase of the diameter of the intermediate position of the pipe. Thus it is possible to prevent the thickness of the bulged portion from becoming excessively thin. Consequently it is possible to shape the bulged portion and the flange portion, with the bulged portion and the flange portion keeping a sufficient thickness.
As apparent from the foregoing description, the construction of coupling exhaust pipes of a vehicle does not have a fear of breakage even though a vehicle body vibrates, does not cause an increase in the weight and cost thereof, and the number of component parts, and can be manufactured easily.
BRIEF DESCRIPTION OF THE DRAWINGS
In the first embodiment, the coupling construction does not have a portion to be welded unlike the conventional coupling construction. Further the coupling construction can be prevented from cracking because a stress does not concentrate on a welded portion. In addition, time and labor can be saved because it is unnecessary to perform a welding process. Further because it is unnecessary to use thick coupling flanges to obtain a face pressure necessary for preventing leak of gas, it is possible to prevent an increase in the weight of the coupling construction and the cost thereof. Furthermore because the flange portions 12, 22 are formed by bending the opening edges 11, 21 of the upstream-side exhaust pipe 1 and the downstream-side exhaust pipe 2 respectively, it is possible to use a smaller number of parts for the coupling construction of the present invention than for the conventional coupling construction in which the coupling flanges 61, 62 (see
Inner peripheral portions 51 of the sandwiching rings 5A, 5B are sectionally curvedly disposed along outer surfaces of the flange portions 14, 24 in the direction in which the flange portions 14, 24 of the upstream exhaust pipe 1 and the downstream exhaust pipe 2 are opposed to each other, with the inner peripheral portions 51 of the sandwiching rings 5A, 5B in contact with the outer surfaces of the flange portions 14, 24. The peripheral portions of the sandwiching rings 5A, 5B are opposed to each other, with the gasket 32 sandwiched therebetween. The sandwiching rings 5A, 5B are coupled to each other at symmetrical positions (see
The coupling construction of the second embodiment does not have a portion to be welded unlike the conventional coupling construction. Further the coupling construction can be prevented from cracking because a stress does not concentrate on a welded portion. In addition, time and labor can be saved because it is unnecessary to perform a welding process. Further because thick coupling flanges are not required to obtain a face pressure necessary for preventing leak of gas, it is possible to prevent an increase in the weight of the coupling construction and the cost thereof. Furthermore because the flange portions 14, 24 are formed by bending the edges 11, 21 of the openings of the upstream-side exhaust pipe 1 and the downstream-side exhaust pipe 2 respectively, it is possible to use a smaller number of parts for the coupling construction of the present invention than for the conventional coupling construction in which the coupling flanges 71, 72 (see
In each of the above-described embodiments, when the flange portions 12, 22 have a sufficient strength, it is unnecessary to bend the edges of the exhaust pipes radially inward or form the reinforcing ribs 13, 23. Further when the sandwiching rings 5A, 5B have a sufficient strength, it is unnecessary to form the reinforcing ribs 52.
Claims
1. A construction of coupling exhaust pipes of a vehicle, wherein an opening edge of an upstream-side exhaust pipe and an opening edge of a downstream-side exhaust pipe opposed to said opening edge of said upstream-side exhaust pipe are bent radially outward to form a circumference of said upstream-side exhaust pipe and a circumference of said downstream-side exhaust pipe as a flange portion respectively; and in the state of said both flange portions are butted to each other through a sealing member disposed between said both flange portions, said both flange portions are mechanically coupled to each other by means of coupling members.
2. A construction of coupling exhaust pipes of a vehicle, wherein an opening edge of an upstream-side exhaust pipe and an opening edge of a downstream-side exhaust pipe opposed to said opening edge of said upstream-side exhaust pipe are bent radially outward to form a circumference of said upstream-side exhaust pipe and a circumference of said downstream-side exhaust pipe as a flange portion respectively; and
- after said both flange portions are butted to each other through a sealing member disposed between said both flange portions, said both flange portions are coupled to each other by means of a pair of sandwiching members which sandwiches said both flange portions therebetween at an outer side of each of said flange portions in a direction in which said both opening edges are opposed to each other.
3. A construction of coupling exhaust pipes of a vehicle according to claim 1, wherein said flange portion is molded radially outward by bending said edges of said openings and radially inward at least once.
4. A construction of coupling exhaust pipes of a vehicle according to claim 3, wherein said flange portion is formed by crushing in a longitudinal direction of a pipe at least one of adjacent bulged portions formed by bulging said pipe radially outward at an intermediate position of said pipe spaced at a predetermined interval from an opening of said pipe in such a way as to superimpose both slopes of each of said sectionally mountain-shaped bulged portions each other.
5. A construction of coupling exhaust pipes of a vehicle according to claim 2, wherein said flange portion is molded radially outward by bending said edges of said openings and radially inward at least once.
Type: Application
Filed: Jan 19, 2006
Publication Date: Jul 27, 2006
Applicant: Nakagawa Sangyo Co., Ltd. (Nishikasugai-gun)
Inventor: Yukihiro Nakagawa (Kasugai-shi)
Application Number: 11/334,403
International Classification: F01N 7/00 (20060101);