| 摘要 |
PROBLEM TO BE SOLVED: To provide a hollow injection-molded article which satisfies the surface quality as an exterior design component, while maintaining a sufficient rigidity, by providing a hollow cross-sectional structure. SOLUTION: As to the values of a molten resin pressure detected by pressure sensors 11 and 12, the fluid pressure in a runner part 3 is higher than that in an ordinary part 5. This is because the viscosity resistance of a molten resin 2 in a cavity 9 is larger in the ordinary part 5 having a relatively small cross section than in the runner part 3 having a relatively large cross section. Accordingly, a pressurized fluid supply means 13 injects a pressurized fluid 10 into the runner part 3 with a pressure in the range from the lower pressure (i.e. the fluid pressure in the runner part 3) out of the pressures in the two parts to the higher one (i.e. the fluid pressure in the ordinary part 5). By executing this pressure control, molding is performed, with the shape of a hollow part 4 in the runner part 3 controlled to be optimum, and the surface quality of a product is improved. COPYRIGHT: (C)2004,JPO |
