| 摘要 |
In an injection molding machine for a thermoplastic resin, a mold clamping hydraulic circuit is constituted as a hydraulic circuit which can be optionally set to a pressure-free or substantially pressure-free state upon completion of closure of a mold mounted to a clamping unit, a movable mold of the clamping unit can be retracted by a low injection pressure by injecting the molten resin by an injection unit, a nozzle port opening to a space of a mold cavity is closed simultaneously with completion for the charge of predetermined amount of resin, and a mold clamping force at a high pressure is generated on the forwarding side of the mold clamping unit thereby proceeding mold clamping to a predetermined position. Accordingly, since the mold is in a pressure-free or substantially pressure-free state, the injection pressure may also be low. Accordingly, an injection amount of resin for one shot can be increased by several times of amount without increasing the pressure of hydraulic cylinder of an injection unit and, further, molded articles several times as great as in the size can be molded without increasing the mold clamping force of the clamping unit. <IMAGE> |
