| 摘要 |
PROBLEM TO BE SOLVED: To surely bond places where divided molding materials flow through a molding cavity to be mutually bonded by providing a passage for injecting the molding material into the molding cavity from a sprue and an escape passage having an inflow pressure chamber in which the molding material is housed under the pressure on the side of the inflow leading end part thereof to a runner. SOLUTION: A sprue 6 is formed to an upper mold and a molding material is injected from a cylinder. The runners 7 in two directions among runners 7 radially formed in four directions from the sprue 6 are injection passages 8 for injecting the molding material M from the sprue 6 into a molding cavity 5. The connection parts formed of thin forming passages of the molded product molded in the molding cavity 5 with burrs formed in the injection passages 8 are molded in a thin-walled state so as to be torn. The runners 7 in the other two directions among the runners 7 are formed into eacape passages 9 so as to be capable of allowing the inflow leading end parts of the molding material M injected from the injection passages 8 to flow out as burrs after the filling of the molding cavity 5. |
