Patent ID: 9719404
Date: 2017-08-01
CPC Classifications: F01N

Claim:
1. A manufacturing method for a muffler comprising: a trimming step of cutting out a dogleg shaped muffler body member from a planar plate, the dogleg shaped muffler body member defining a first part and a second part and a bending portion between the first part and the second part, wherein a length of the bending portion of one side of the dogleg shaped muffler body member is different than a length of an opposing side of the bending portion of the dogleg muffler body member; a bending processing step of processing the muffler body member into a tube by advancing the muffler body member between an upper roller and a lower roller of a bending machine while adjusting an advancing direction with a guide and by changing a relative position of the upper roller and the lower roller, thereby producing a tubularly-processed muffler body member; a first joining step of joining two ends of the tubularly-processed muffler body member in a long side direction of the dogleg shaped muffler body member; an insertion step of inserting an inner structural member to the inside of the tubularly-processed muffler body member; a second joining step of joining caps to opening portions of the tubularly-processed muffler body member to seal the tubularly-processed muffler body member; and a third joining step of joining an air intake joint and an exhaust pipe to the sealed muffler body member.