| 摘要 |
PURPOSE:To reliably pack resin into every part, smoothly perform degassing and prevent the wet face and warp of a disc case from being generated by disposing an injection port at two positions which are covered and hidden by an ordinary shutter and which are located on the carved face of a mold corresponding to the outside of a disc-body containing part, forming a degassing part at a central part on a far wide from the injection ports, and providing a resistance part against the flow of the resin at a position corresponding to a spring containing part with a center line therebetween. CONSTITUTION:An injection port 5 for a molten resin is arranged at two positions symmetrical to a center line l and formed at these positions which are covered and hidden by the shutter 6 of an upper case 1 and which correspond to the outside of a disc-body containing part 1i, and a degassing telescopic tube 8 is disposed on a movable mold plate 3 at a central part on a far side from the injection ports 5. Further, a resistance part 1m is provided at a position opposed to a spring containing part 1j with the center line l therebetween, and its resistance is made substantially equal to the resistance of the flow of the molten resin supplied from the right and left injection ports 5. The molten resin injected from each injection port 5 into a cavity 4 is packed from one end side to the other end side of the cavity and eventually reaches the degassing telescopic tube 8, and a final weldline is aligned with the center line l in a balanced state. |
