PURPOSE: To reduce the manufacturing cost and increase strength by a method wherein a joint part of an external container and an internal container of synthetic resin is formed of a soldered joint part and a joint part welded by ultrasonic wave.
CONSTITUTION: After an internal container 24 with a projection 28 and an external container 11 are set, ultrasonic wave vibration is applied to the projection 28 which is formed at a joint part 14 to melt the projection 28 so that the internal container 24 and the external container 11 are welded together by ultrasonic wave. Further, welding heat generated during the ultrasonic wave welding melts a soldered layer 26 which is interposed in the joint part 14. That is, the ultrasonic wave applied to the joint part 14 melts the projection 28 of synthetic resin and the soldered layer 26 at the same time. When the ultrasonic wave welding is finished, solder in the soldered layer 26 is cooled and solidified. Thus the internal container 24 and the external container 11 are jointed at an ultrasonic wave welded part 28' by the ultrasonic wave welding and by soldering.
KOMIYA YASUHIKO
MARUMO SHINICHI
MORITA MINORU
