Injection molding machine

An injection molding machine including a heating cylinder configured to melt resin and a screw provided inside the heating cylinder, comprising:

• a first driving device configured to rotate the screw inside the heating cylinder;
• a second driving device configured to move the screw forward and backward inside the heating cylinder;
• a metering control section configured to, by controlling the first driving device and the second driving device, move the screw backward while rotating the screw forward so as to meter an amount of the resin while melting the resin, and thereafter rotate the screw in reverse to thereby reduce a pressure of the resin;
• a first sensor unit configured to detect the pressure;
• a second sensor unit configured to detect one or more kinds of physical quantities that affect change of the pressure, from the injection molding machine;
• and
• a prediction section configured to predict decompressing rotation information including at least one of a rotation angle by which the screw should be rotated in reverse after the metering in order to reduce the pressure to a target pressure and a rotation speed at which the screw should be rotated in reverse after the metering in order to keep an amount of change of the pressure per unit time at a predetermined level or lower, based on the pressure detected by the first sensor unit and the one or more kinds of physical quantities detected by the second sensor unit,
• wherein the metering control section is configured to control the first driving device based on the decompressing rotation information predicted by the prediction section,
• further comprising a check ring that opens or closes a resin flow path in the heating cylinder in accordance with the controlling of the screw,
• wherein the check ring receives pressure from the resin that is pressurized and fed from a rear to a front in the heating cylinder and then opens the resin flow path.

An injection molding machine including a heating cylinder configured to melt resin and a screw provided inside the heating cylinder, comprising:

• a first driving device configured to rotate the screw inside the heating cylinder;
• a second driving device configured to move the screw forward and backward inside the heating cylinder;
• a metering control section configured to, by controlling the first driving device and the second driving device, move the screw backward while rotating the screw forward so as to meter an amount of the resin while melting the resin, and thereafter rotate the screw in reverse to thereby reduce a pressure of the resin;
• a first sensor unit configured to detect the pressure;
• a second sensor unit configured to detect one or more kinds of physical quantities that affect change of the pressure, from the injection molding machine;
• and
• a prediction section configured to predict decompressing rotation information including at least one of a rotation angle by which the screw should be rotated in reverse after the metering in order to reduce the pressure to a target pressure and a rotation speed at which the screw should be rotated in reverse after the metering in order to keep an amount of change of the pressure per unit time at a predetermined level or lower, based on the pressure detected by the first sensor unit and the one or more kinds of physical quantities detected by the second sensor unit,
• wherein the metering control section is configured to control the first driving device based on the decompressing rotation information predicted by the prediction section,
• further comprising a check ring that opens or closes a resin flow path in the heating cylinder in accordance with the controlling of the screw,
• wherein, when the resin is injected, the check ring receives pressure from the resin accumulated on a front side of the ring and then closes the resin flow path.