PURPOSE: To reduce the amount of shape memory alloy by fitting a fastening ring made of shape memory alloy on the outer periphery of the enlarged diametrical connection end part of a pipe, by forming a seal layer on the inner circumference of the enlarged diametrical connection end part, by inserting a connection end part into the enlarged diametrical connection end part, and then by elevating the temperature of the fastening ring up to no less than a transition temperature through heating.
CONSTITUTION: An enlarged diametrical connection end part 2 is formed on the end part of an aluminium pipe and the like 1 to be connected. A fastening ring 4 made of shape memory alloy of such as copper system (Cu-Al-Zn) is inserted into the outer periphery of the enlarged diametrical connection end part 2. The fastening ring 4 is cooled down to the temperature of no more than a transition temperature, before it is inserted into the enlarged diametrical connection end part 2 of the aluminium pipe 1. It is heated by electrifying heating method and the like, and is elevated up to no less than the transition temperature, and the fastening ring 4 is thermal-contracted in a radius direction. The connection between the enlarged diametrical connection end part 2 and the connection end part 6 of a connector 5 can be consolidated thereby. As a result, a liner for complementing the contract ratio of the shape memory alloy can be omitted, and the amount of the shape memory alloy to be used can also be reduced, and a cost can be reduced thereby.
UENO YOSHIBUMI
KITSUTAKA KIYOKORE
