MOLD MOLDING METHOD OF PARTS WITH STEPPED HOLE

PURPOSE:To reduce the number of parts and cost and to miniaturize a shape, by a method wherein mold tightening is done by making a split sleeve slide to a desired position of a core by pushing the split sleeve through the edge part of a central hole of a cavity by driving a cavity component and mold molding is made by pouring a molding resin into the cavity. CONSTITUTION:When a cavity component 10 is made to drive in the direction of an end face component 23, the inside diameter of a split sleeve 22 is expanded by opening a slit part, the split sleeve 22 is pushed by the bottom part of a cavity 11 and slides on the external circumferential surface of the main body 18 of a core. Driving of the cavity component 10 is suspended at a position where a gap between an end part on fixed part 17 side of the split sleeve 22 and an end face of the fixed part 17 has become a hole width of a small diameter hole 8. Then the cavity component 10 is suspended at a position where the cavity component 10 has been returned by the hole width of the small diameter hole 8, and parts 7 with a stepped hole is molded by pouring and pressing molding resin from a pouring hole 12. Then a mold is opened by making the cavity component 10 recede and the parts 7 with the stepped hole are removed off from a core 16 and a core shaft 20. With this construction, the parts 7 with the stepped hole is obtained at low cost as the number of parts is one and a shape can be miniaturized further.