To adjust a length of a pipe simultaneously with forming an enlarged part by plastic deformation, in a method of manufacturing a pipe having the enlarged part on its end part as the joint part.
An arbitrary position of the pipe 20 is clamped by pipe chucks 3, 3', the end part of the pipe 20 is enlarged by a tool such as an enlarging punch after a connector 62 is fitted, and is caulked to the connector 62 from the inside. As a pipe variation absorbing part 71 is formed on a part of an inner face of the connector 62 as a relief space of a pipe material, the residual material is absorbed there in forming the enlarged part by the tool, and a length of the pipe 20 is shortened to be corresponded to a predetermined length. In a case when the connector 60 is not used, a dividable female jig having the similar inner face shape is used for the connector 60. The pipe variation absorbing part 71 may be formed not only on a tip part of the pipe 20 but on an inner face of the connector 60 corresponding to an intermediate part.
SAKAI TSUYOSHI
KATO SHINJI
Jun Tsuruta
Shigeki Tsujimoto
Masaya Nishiyama