Patent ID: 8740605

Claim:
A spring tube melting machine for an air suspension system comprising: an inner molding part having an upper plate, which has an air injection nozzle and a plurality of joining keys formed on the outer circumferential surface of the upper plate, a finish plate detachably mounted and having an end fixed to the lower surface of the upper plate in such a way as to communicate with the air injection nozzle and having a reference projection formed at the other end thereof so that both ends of the finish plate are sealed and fixed, and an expandable tube inserted into a half-finished spring tube; and an outer molding part having a heating core, which is heated by a heat source while the expandable tube of the inner molding part is accommodated and has a reference recess corresponding and interlocking with the reference projection, and a joining key recess formed at an entrance of the heating core in the form of “ ” shape in correspondence with the joining key.