| 摘要 |
PURPOSE:To prevent the occurrence of flashes and to reduce the weigh fluctuation by half, by dividing a dwell pressure process conpensating the shrinkage accompanied with cooling and solidifying a molten resin into a plurality of controlling sections, setting at least one section by the position of an injection means and controlling the pressure. CONSTITUTION:When the position of a screw reaches a position Sp and a filling process is switched to a dwell pressure process, pressure controlling is started and the pressure is controlled at P1 set in a pressure setting device. At this instance, the pressure detected by a pressure detecting device 5 is compared with the set value P1 in a comparing device 21, and the difference is sent to a scequence controller after it is amplified by means of an amplifier 23. Feedback controlling is then carried out by means of a leaf valve 10. During this time, when the screw position reaches a switching point SP1 from the primary dwell pressure to the secondary dwell pressure, the primary dwell pressure is finished and switched to the secondary pressure. On the secondary dwell pressure P2, feedback controlling is carried out in the same way as in the primary dwell pressure.
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