PURPOSE: To take out easily a model without destroying the same and reduce the post-manufacturing processes, by a method wherein at the time of casting of a core, an ejector pin is buried beforehand into the core.
CONSTITUTION: A parting surface forming plate 3 and model 4 are provided within a casting frame 2 on a bottom plate 1. Resin 5a is cast, an opening part is covered with an upper plate 6, which is reversed after temporary cure of the same, the parting surface forming plate 3 and bottom plate 1 are removed, a fitting plate 10 having an ejector pin 9 to an outer circumference of which a mold release material 9a is applied is set up to the casting frame 2, into which resin 5b is cast and cured secondarily. Then an upper part is removed from the casting frame 2 and the model 4 is separated easily from the casting frame 2 without destroying the model 4. Then since the ejector pin hole 9a is formed already into a core 5B to be obtained by performing finish processing of the outer circumferential parts of the cured resin 5a, 5b and post-processing is unnecessary, a sprue 13 is formed in a cavity 5A, those of which are incorporated into a mold base and made into an injection mold.
HAMANO SUGURU
SUZUKI KENICHI
SAKATA TADAO
| JPS5120950A | 1976-02-19 |