| 摘要 |
PURPOSE:To decrease the height size of a mold clamping device and to speed up the operation for mold opening and closing by constituting the mold clamping device into a two-layered construction consisting of a stationary platen and movable platen. CONSTITUTION:The movable platen 14 moves upward and downward at a high speed when an oil pressure is supplied to or discharged from a mold closing and opening cylinder 16. The large-diameter hole part 26a of a mold clamping cylinder 26 moves on the outside periphery of a mold clamping piston 24; therefore, the hydraulic fluid in the cylinder 26 is movable by passing along the outside periphery of the piston 24 and the outflow of the hydraulic fluid in the cylinder 26 to an external hydraulic device is prevented. There is no need for supplying the hydraulic fluid from the external hydraulic device to the inside of the cylinder 26. The piston 24 fits into the small- diameter hole part 26b of the cylinder 26 when a movable mold 20 descends down to just before the mold contacts with a stationary mold 18. The force for pressing the movable platen 14, i.e., mold clamping force is generated when the oil pressure is supplied to the hole part 26a. Injection molding is executed in such mold clamping state. The oil pressure is supplied to the small-diameter hole 26b side to release the mold clamping force. upon completion of molding. |
