| 摘要 |
PROBLEM TO BE SOLVED: To mold a plurality of throttle members entirely common except a diameter of a fixed throttle hole by replacing only a core pin for forming the fixed throttle hole of the member, and molding the members having different holes. SOLUTION: A molten resin is cast in a cavity 50 for forming by a core block 52 of a movable mold 71, slide cores 54, 55, a core pin 51 and a core block 52 of a fixed mold 72, and a throttle member is molded. A fixed throttle hole of a throttle member is molded by an end 51a of the pin 51, and an oblique surface is molded by an oblique surface 51d of the pin 51. When a throttle member having only the fixed throttle hole and oblique surface of the member being different and the same of the other state is molded, only the pin 51 may be replaced with a different core pin. In the case of molding an engaging hole of a lens holding member, it is molded by a slide core 54 or a slide core 55 laterally opened or closed by an angular pin 56. Thus, a throttle member having different fixed throttle hole can be molded only by replacing the pin 51. |
