VALVE GATE TYPE MOLD ASSEMBLY

摘要

PROBLEM TO BE SOLVED: To uniformly heat the molding compound in a material passage in a valve gate type mold assembly equipped with a valve sleeve. SOLUTION: The valve gate type mold assembly is equipped with a fixed mold 21 and a movable mold 22 both of which are mutually opened and closed to form a cavity 23 at mold clamping and an annular gate 73 for opening the material passage 42 provided to the fixed mold 21 to the cavity 23. A valve device 33 is equipped with a valve casing 34 having the material passage 42 therein, the cylindrical valve sleeve 71 for opening and closing the gate 73 and the center pin 72 coming into contact with the core pin 82 of the movable mold 22 at mold clamping. A ring heater 61 is provided in the vicinity of the gate 73 of the valve casing 34. Since the center pin 72 comes into contact with the movable mold 22 at mold clamping, heat is easy to escape to the movable mold 22 but the molding compound in the material passage 42 can be heated even on the side of the gate 73 by the heating of the ring heater 61.