| 摘要 |
PURPOSE:To improve the strength of a CRT holding part by a method wherein a pressurized gas is injected in a cavity by compressing a gas pressure in a cylinder by a piston, slightly after an injection of a molten resin, and the feeding of the gas pressure is continued even after the completion of the pressurization of the molten resin, and the high pressure gas is injected at least in the vicinity of the CRT holding part. CONSTITUTION:A molten resin 24 is injected in a cavity of dies 19, 20 from an injection cylinder 22. Then, slightly after the injection of the molten resin 24, a gas in a gas press-feeding cylinder 25 is compressed by a piston 26, and the gas is fed in the cavity through a torpedo 28 and gas injection port 29. The press-feeding of the gas is continued even after the completion of the pressurization of the molten resin. By this method, a cavity 32 is formed by the injected gas in the vicinity of a gate 21 of a cabinet 10, especially at a thicker part 16. A secondary pressure is applied to the thicker part 16 through the cavity 32, and the pressure is applied to the inside without loss at the corner part. By doing so, a sink mark is prevented from generating, and a thick stop boss can be formed. |
