MANUFACTURING METHOD OF BENT PIPE HAVING BELLOWS, AND BENT PIPE HAVING BELLOWS

摘要

PROBLEM TO BE SOLVED: To provide a bent pipe with excellent yield in which steep bending can be performed from a base portion of a bellows without collapsing any ridge of a bellows part, or without taking a considerably long distance from the bellows part.;SOLUTION: In the bent pipe having a bellow part, a straight pipe section is formed on each of both end sides, and the bellows part is formed between both straight pipe sections. After the straight pipe sections are formed in a first process, the bending is executed between the straight pipe sections to form a bent pipe of the desired angle in a second process. Thereafter, the bulging is executed to a portion drawn from a base portion of the bellows part of the bent pipe of the desired angle to form the bellows part in a third process.;COPYRIGHT: (C)2010,JPO&INPIT