| 摘要 |
PURPOSE:To improve productivity by shortening removing time of a core, by a method wherein after a molded product has been molded by making use of a core formed by clogging a hollow body composed of a fragile material by filling the inside of the hollow body with a filler, the hollow body is removed through breaking by taking out the filler. CONSTITUTION:A hollow body 4 is composed of a fragile material and possesses a filling port 7 of a filler. The hollow body 4 is filled with a granular thing 8 composed of the same material as the hollow body 4 through the filling port 7 and a core 10 is formed by clogging the filling port 7. The core 10 is arranged in a bottom force 3, a top force 2 and the bottom force 3 are clamped together, a fiber reinforced plastic material is cast into a molding air gap part 11 and molding is completed by solidifying the same. Then the top and bottom forces 2, 3 are broken, a molded product 12 is unloaded, the filling port 7 is opened and the granular thing 8 is unloaded. Then a temperature of the hollow body 4 is change suddely by passing a heating medium and cooling medium alternately through a hollow part 4b of the hollow body 4 and numberless cracks are generated. Then molded product is vibrated, a small piece where the cracks are generated is removed and the molded product is obtained. |
