MOLD APPARATUS FOR INJECTION MOLDING

PROBLEM TO BE SOLVED: To provide a mold apparatus which forms triangular through holes in triangular inclined plate parts located on both sides of a top part and can correctly form a shade member having a fractal structure in which a V-shaped undercut part is provided toward the lower part of the top part from the mutually parallel sides of these through holes without generating an excess thickness part needing cutting work at a slide core tip.SOLUTION: The tip faces of front and rear slide cores 21a-1 and 21b-1 sliding on a mold during molding are made to face each other in a butt state, the lower surface of a flat projected piece 12a installed in the base end part of a pyramid-shaped core 12 for molding both side through holes facing each other with a top part in a molding placed between them is made to closely contact the tip part upper surface both side parts of the slide core to form a cavity for molding a part of the top part on the upper surface of the slide core between the opposite tip surfaces of the flat projected piece 12a, and additionally an undercut part is molded by the downward slope of the core 12.