Manufacturing process for filler tube

A manufacturing process for filler tube to be weld to a fuel tank at an opening thereof, and made of thermoplastic resin,

• the filler tube comprising:
• a cylinder-shaped body;
• a flange elongating outward radially from the cylinder-shaped body at an end thereof, and having an end face to be welded to the fuel tank;
• and
• a locking portion disposed in the cylinder-shaped body on an outer peripheral side thereof;
• a workpiece for the filler tube, the workpiece comprising:
• the cylinder-shaped body;
• a cylindrical to-be-molded portion serving as a site before flare molding the flange;
• and
• the locking portion;
• the manufacturing process using an outer peripheral mold, and an inner peripheral mold;
• the outer peripheral mold comprising:
• a counter-welding-face forming portion capable of supporting the cylinder-shaped body of the workpiece on an outer peripheral face thereof, and capable of forming a counter-welding face in the flange;
• and
• a to-be-locked portion locking with respect to the locking portion in an axial direction thereof;
• the inner peripheral mold comprising:
• a welding-face forming portion insertable into the to-be-locked portion of the workpiece at least, and capable of forming a welding face in the flange;
• the manufacturing process comprising:
• a workpiece arrangement step of arranging the workpiece onto the outer peripheral mold not only to axially lock the to-be-locked portion with respect to the locking portion but also so as to make the outer peripheral mold, which is set at a predetermined temperature, support the cylinder-shaped body of the workpiece on an outer peripheral face thereof;
• and
• a flare-molding step of following the workpiece arrangement step to flare mold the flange by inserting the inner peripheral mold, which is set at a higher temperature than the predetermined temperature of the outer peripheral mold, into the to-be-molded portion on an inner peripheral side thereof, and by relatively moving the outer peripheral mold and the inner peripheral mold in an axial direction thereof to make the counter-welding-face forming portion and the welding-face forming portion clamp the to-be-molded portion therebetween in the axial direction.