Patent Application
20050257982
The present invention relates to an exhaust system, and more particularly to a symmetrical flange assembly, which may be utilized in multiple locations throughout the exhaust system to connect exhaust pipe sections.
Exhaust systems typically include several connected exhaust pipe sections. A flange on each exhaust pipe section commonly connects adjacent exhaust pipe sections. The flanges are typically rectilinear plates with a circular aperture that receives an end of each exhaust pipe section. Typically, the flanges have been stamped from sheet metal. The flanges are welded onto ends of the exhaust pipe sections and the flanges are attached together with fasteners.
Due to size and strength requirements, the flanges may be expensive to manufacture. A large press has been required to stamp the flanges. The resulting expense of the flange may be a large percentage of the overall exhaust system expense.
Accordingly, it is desirable to provide an inexpensive flange for an exhaust system.
The exhaust system according to the present invention provides a flange assembly made from multiple flange portions. The flange portions may be formed of a powdered metal and may be identical. A flange portion formed from powdered metal may be manufactured by a less expensive manufacturing process than the prior art. The use of identical flange portions reduces the total number of parts that would otherwise be required to utilize varying flange portions.
The disclosed flange portions include steps at each peripheral edge. The steps are approximately one-half a nominal thickness of the flange portion. Preferably, two flange portions come together to form the flange assembly. The steps at the peripheral edges of each flange portion overlap with a corresponding peripheral edge from the other flange portion. The steps arranged in this overlapping relationship provide a reliable structure for properly positioning the flange portions on an exhaust pipe section.
The flange portions have a curved inner peripheral surface between the peripheral edges that extends beyond 180°. Thus, the steps will serve to hold and position the flange portions on the exhaust pipe section. Of course, it is possible the exhaust pipe section will have a shape other than circular, and the inner peripheral surface of the flange portions will be modified accordingly in such an instance.
The present invention therefore provides an inexpensive alternative to the prior art flange for an exhaust system.
The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows:
The exhaust pipe assembly 12 includes an exhaust pipe 16 and a flange assembly 18 mounted to an end segment 20 of the exhaust pipe 16 such as through welding. The muffler assembly 14 includes a muffler exhaust pipe 22, a muffler 24, and a flange assembly 26 mounted to an end segment 28 of the muffler exhaust pipe 22 such as through welding. The flange assemblies 18, 26 are attached together through a fastener arrangement, such as bolts 30 and nuts 32. Other fasteners such as rivets can be utilized.
Each flange assembly 18, 26 is disclosed as being assembled from identical flange portions 34, and is manufactured of a powdered metal. Most preferably a stainless steel powdered metal is utilized, although other appropriate powdered metals could be utilized. Of course, each flange portion 34 is smaller than the assembled flange assembly 18, 26. Because of the smaller size and the powdered metal composition, the flange portions 34 may be manufactured by a lower tonnage press to thereby decrease manufacturing expense. That is, the flange portions 34 are more economical to produce than conventional one-piece flanges. Furthermore, because each flange portion 34 is identical, the part count per exhaust system 10 is not increased.
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Plane A is defined as bisecting an open end 48 of the exhaust pipe 16. One flange portion 34 is assembled on each side of the plane A such that the partial circular pipe apertures 36 from the two flange portions 34 form a complete aperture which surrounds the exhaust pipe 16. The steps 46 at each end surface 52 of each flange portion 34 are overlapped with mating steps 46 from the other flange portion 34. As can be appreciated, a curved inner peripheral surface 54, defined by the partial circular pipe aperture 36, extends beyond 180°. In this manner, the steps 46 cross the plane A, and thus have surfaces that will begin to curve back inwardly to catch each flange portion 34 on the exhaust pipe 16. That is, since the steps 46 extend beyond 180°, they will begin curving back in an opposed direction near the peripheral edges 50. This will assist in holding the flange portions 34 on the exhaust pipe 16.
The flange portions 34 are positioned within an appropriate welding jig, and held while being welded to the exhaust pipe 16. Preferably, a weld joint W secures the flange portions 34 to the exhaust pipe 16 about the entire circumference of the exhaust pipe 16. Of course, a partial weld joint may also be utilized. Notably, the index mark 42 on each flange portion 34 is located diagonally transverse to each other relative to plane A. The index mark 42 on each flange portion 34 assists in properly positioning the flange portion 34 within the welding jig.
While the flange portions 34 are shown as fully surrounding the exhaust pipe 16, the present invention would extend to the use of multiple flange portions formed of powdered metal that do not necessarily fully surround the exhaust pipe 16. Moreover, while the two flange portions 34 that come together to define a flange assembly 18 are shown as identical, the present invention would also extend to flange assemblies formed of multiple flange portions that are not identical. In addition, while two flange portions 34 are shown as providing the flange assembly 18, more than two flange portions may also be utilized.
The foregoing description is exemplary rather than defined by the limitations within. Many modifications and variations of the present invention are possible in light of the above teachings. The preferred embodiments of this invention have been disclosed, however, one of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. For that reason the following claims should be studied to determine the true scope and content of this invention.
