Method of manufacturing piping having joining portion

摘要

An arbitrary position of a pipe is clamped and a connector is engaged with the pipe. Then, an end portion of the pipe is expanded with a tool such as a diameter expanding punch so as to caulk the pipe to the connector from inside. As a pipe fluctuation-absorbing portion, which is a relief space of pipe material, is provided in a portion of an inner face of the connector, when the diameter-expanding portion is formed, an excess pipe material is absorbed there and the length of the pipe is reduced and adjusted to an appropriate value. A portion in which the pipe fluctuation-absorbing portion is formed is not limited to a forward end portion of the pipe but it may be formed on an inner face of the connector corresponding to an intermediate portion.