VALVE GATE TYPE MOLD ASSEMBLY AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a valve gate type mold assembly capable of smoothing the inner surface of a material passage and capable of smoothly filling a product cavity with a molding material, and its manufacturing method. SOLUTION: A valve device 11 has a valve casing 12 having a spiral material passage 31 formed therein. The valve casing 12 is composed of an insert 41 and an outer peripheral body 51 and the outer peripheral body 51 is divided to form divided outer peripheral bodies. A DC current and/or a pulse current is allowed to flow through the insert 41 and the outer peripheral body 51 to temporarily join both of them, and the insert 41 and the outer peripheral body 51 in the temporarily joined state are heat-treated at a predetermined atmospheric temperature to form the spiral part 35 of the material passage 31 between the insert 41 and the outer peripheral body 51. The inner surface of the material passage 31 can be kept smooth without protruding a welding auxiliary material into the material passage 31. COPYRIGHT: (C)2006,JPO&NCIPI