| 摘要 |
Torques and resin pressures applied to a screw (1) are detected during the forward movement of the screw and coefficients of correlation between the detected torques and resin pressures are calculated. When the check ring (3) is open, the flight (5) of the screw receives resin pressure, and the screw torque increases proportionally to the resin pressure due to resin backflow, so the coefficients of correlation between the screw torques and the resin pressures are higher than a reference value. When the check ring closes, the flight of the screw no longer receive resin pressure, so the screw torque decreases and the coefficients of correlation become lower than the reference value. The check ring is determined to be closed when the coefficients of correlation become lower than the reference value.
|
