| 摘要 |
PURPOSE:To release a product having no sticking from a mold by the simple structure without applying mold release agent. CONSTITUTION:A core 3 is inserted into a cavity 5 constituted with forming molds 1, 2. The core 3 is made of two members of an inside member 31 and an outside member 32, and the inside member 31 is formed with a metal raw material having low coefficient of linear expansion and the outside member 32 is formed with a metal raw material having high coefficient of linear expansion and also, the cross sectional surface shape in the direction crossed at the right angle with the drawing direction of the product is made smaller along the drawing direction in the ratio of the inside member 31. Draft is formed on the outer surface of the core 3 based on the difference of coefficients of linear expansion according to cooling of molten metal 6 to execute the mold releasing. |
