PURPOSE: To suppress the compression of a resin composite tube, and to bend the tube without the occurrence of a failure such as rupture, various deformations, etc., by holding the tip part of the tube into which a plug with a diameter larger than a core bar is inserted, with a clamp die.
CONSTITUTION: The part of the mandrel 12 of a core bar 1 is inserted to a part 2a to be bent of a straight resin lining tube 2, and a plug 3 is inserted into the tip part of the tube. Bending is performed in the same way as the traditional way with a bender by holding the tip part of the tube into which the plug 3 is inserted, with a clamp die 5. Consequently, since the plug 3 exists, the resin lining tube 2 is not excessively put among booster die 6, wiper die 7, and core bar 1. Therefore, the occurrence of a failure such as the deformation of the resin lining tube 2, etc., is prevented, and the tube can be bent.
NAKADA HIROYUKI
KAGOSHIMA EIICHI
