TUBE END DIAMETER REDUCING METHOD OF EXHAUST SYSTEM OUTER CASE AND EXHAUST SYSTEM OUTER CASE WHOSE TUBE END IS REDUCED IN DIAMETER

摘要

PROBLEM TO BE SOLVED: To provide a tube end diameter reducing method of an exhaust system outer case which can prevent the outer case from being deformed at crimping work and an exhaust system outer case whose pipe end is reduced in diameter.;SOLUTION: In a tube end diameter reducing method, a plurality of triangular fin-like parts 31, (33) are formed in a tube end of an outer case 3 by crimping work employing a plurality of split molds so as to conically reduce the diameter of the tube end. The crimping work is applied to the boundary with a part to be subjected to crimping work in the outer case 3 with a reinforcing bead 35 circumferentially formed in advance.;COPYRIGHT: (C)2008,JPO&INPIT