| 摘要 |
PURPOSE:To make it possible to take out a molded item without being caught by a local mold by a method wherein the local mold, by the protrusion of which in the cavity of a mold the recessed portion of a molded item is molded, is provided sinkably in said cavity and, in addition, shape memory alloy is employed in a mechanism to sink said local mold. CONSTITUTION:When a mold is closed, a local mold 5 is sunken. By pouring resin, the heat of the resin stretches a shape memory alloy 8, resulting in projecting the local mold 5 in a cavity 3 until it comes into contact with the opposing surface of the cavity. As a result, a molded item 4 has a hole 4b having the shape of the local mold 5. Since the temperature of the shape memory alloy 8 descends about the time when the resin hardens, the alloy restores its initial short shape and the local mold 5 is again brought in the sunken state. As a result, when the molded item 4 is taken out upwards by opening a fixed mold 2, the taking-out of the molded item can be done without being hindered by the local mold 5. |
