| 摘要 |
PROBLEM TO BE SOLVED: To more accurately discriminate the quality of a molded product or the adjustment of the molding condition thereof by more accurately detecting the closing timing of a non-return valve. SOLUTION: When a screw is advanced after the completion of a metering process, the non-return valve of the leading end of the screw is moved in an open state and a resin flows in a direction opposite to the injection direction of a resin. Torque is applied to the screw by the backflow of the resin and the load in a rotary direction applied to the screw is increased. When the resin passage is closed by the non-return valve, the torque applied to the screw is reduced and the peak point of time of the torque of the screw is detected as the closing point of time of the non-return valve. Physical quantity such as torque, the screw position, etc., is detected at the peak point of time of the torque. Since the closing point of time of the non-return valve is accurately detected, the correction of an injection/holding pressure changeover position or an injection speed changeover position can be more accurately adjusted. Further, the quality of the molded product can be accurately discriminated on the basis of the detected physical quantity. COPYRIGHT: (C)2008,JPO&INPIT
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