| 摘要 |
PURPOSE:To punch the central hole of a disk, while the strain due to nozzle- touch is removed, and then a cut pin and a sprue bush are relatively moved. CONSTITUTION:A cut pin 5 and a nozzle-touched sprue bush 4 are provided on a mold, and the gate parts 32 opposed in a freely advancing and retreating manner are formed in the center of a disklike cavity 3, and then the central hole of the gate part 32 for the cavity 3 is formed by the relative movement of the cut pin 5 to the sprue bush 4. A hydraulic acting chamber 14 is provided on the stationary side of the mold, and the hydraulic pressure resisting resin pressure is caused to act on the acting chamber at the timing of the occurrence of resin pressure in filling process, whereby the cut pin 5 and the sprue bush 4 are synchronously advanced and retracted independently in the semisolidified condition of a product in the gate part 32. |
