VALVE GATE TYPE MOLD ASSEMBLY AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a valve gate type mold assembly provided with a material passage having a smooth inner surface, and its manufacturing method. SOLUTION: A valve device 11 has a valve casing 12 which has the material passage 21 formed therein. The joining surfaces 32 and 32 of a plurality of valve casing constituting members 31 and 31 are pressed under predetermined pressure and a DC current and/or a pulse current is allowed to flow through a plurality of the valve casing constituting members 31 and 31 while keeping the pressed state to temporarily join the joining surfaces 32 and 32 of a plurality of the valve casing constituting members 31 and 31. A plurality of the valve casing constituting members 31 and 31 in the temporarily joined state are heat-treated at a predetermined atmospheric temperature to form the material passage 21 between a plurality of the valve casing constituting members 31 and 31. A plurality of the valve casing constituting members 31 and 31 can be joined without using a welding auxiliary material at all and the inner surface of the material passage 21 can be kept smooth without protruding the welding auxilary material into the material passage 21. COPYRIGHT: (C)2006,JPO&NCIPI