METHOD FOR INJECTION-MOLDING INSERT-CONTAINING RESIN GEAR

摘要

PROBLEM TO BE SOLVED: To prevent the generation of voids and to achieve the dimensional stability of teeth while improving appearance, in the molding of an insert- containing resin gear by an injection molding method. SOLUTION: In the method for injection-molding the insert-containing resin gear having a resin layer for forming gear teeth to the outer periphery of an insert, a molten resin is injected in an injection mold 1 from pin gates 3 provided at five or more points in such a state that the insert 2 is supported at the central part 4 of the injection mold 1 and the distance between each of the pin gates and the insert is set to 0.5 mm or more to allow the injected molten resin to once impinge against the insert before sending the same to the tooth portion of the outer periphery of the insert.