摘要 |
A method for joining pipes in which a first pipe in which at least one portion to be engaged is sunk inward to an inner circumferential surface side provided in an outer circumferential surface of an end portion of the first pipe, and a second pipe made of thermoplastic resin are joined together. The method includes: inserting an end portion of the first pipe into an end portion of the second pipe; and as a result of a component that transmits ultrasonic waves against an outer circumferential surface of the second pipe that corresponds to the portion to be engaged of the inserted first pipe, softening the second pipe by the ultrasonic waves so that an engaging portion is formed which is made to protrude into the portion to be engaged and is positioned on the inner circumferential surface of the first pipe. |