To improve the strength and the appearance by casting a molding material, pushing up cold slag to a point just short of penetration of a shut-off pin through a cavity after the cold slag is solidified and before the molding material in the cavity is solidified, and removing a part containing the cold slag after die release.
Before a molding material becomes solidified after its supply into a cavity 6 from a gate opening 4, a cold slag 10 and a molding 13 are pushed up by moving the a shut-off pin 11 with an almost same section as the cold slag 10 in such a state that only the cold slag 10 is solidified. The movement of the shut-off pin 11 is to such a degree that the cold slag 10 and the molding 13 are allowed to enter into the gate opening 4. Next, the molding material in the cavity 6 is made to solidify and a stripper plate 8 is pushed up using an ejector pin 9 to release the molding 13 from a die. After that, the molding 12 is set in the die to form a hole in the part between the cold slag 10 and the molding 13 by punching the part by means of a punch.
KOZAI TAKASHI
KOSUGI YOSHIMICHI
OOTANI RIYUUJI
