Abstract: A measurement control method uses an ending target position Xes calculated by adding a prescribed length Ls to a measurement ending position Xe. A rotation rate pattern Ar for rotating a screw 2, a back pressure Ps in relation to the screw 2, and a retraction rate pattern Ab for the screw 2 to retract, are set in advance. The remaining rotation rate pattern Ar to stop the rotation of the screw 2 at the ending target position Xes from the detected screw position X, is calculated at the time of measurement, and the rotation of the screw 2 is stopped based on the calculation. Further, the remaining retraction rate pattern Ab is calculated from the detected retraction rate Vd, and the retraction of the screw 2 is stopped based on the calculation. The result is the stopping of the screw at the measurement ending position Xe.

Abstract: Leak of a metered resin by backflow in injection filling is prevented not depending on reverse rotation of a screw but by closing a ring valve by controlling a screw forward movement speed in injection filling. An injection filling speed and a valve closing operation speed are set to the screw forward movement speed. The valve closing operation speed is different from an initial speed of the injection filling speed, and the operation time thereof is set to the time necessary for moving the injection screw by a distance capable of performing the valve closing after the end of metering. The valve closing is performed with the set operation speed and the set operation time.

Abstract: An ending target position Xes in which a prescribed length Ls is added to a measurement ending position Xe, a rotation rate pattern Ar for rotating a screw 2, a back pressure Ps in relation to the screw 2, and a hypothetical retraction rate pattern Ab for the screw 2 to retract, are set in advance while the remaining rotation rate pattern Ar to stop the rotation of the screw 2 at the ending target position Xes from the detected screw position X, is predicted by calculation at the time of measurement, and the rotation of the screw 2 is stopped based on the prediction. Further, the remaining retraction rate pattern Ab is predicted by calculation from the detected retraction rate Vd, and the retraction of the screw 2 is stopped based on the prediction.

Abstract: Leak of a metered resin by backflow in injection filling is prevented not depending on reverse rotation of a screw but by closing a ring valve by controlling a screw forward movement speed in injection filling. An injection filling speed and a valve closing operation speed are set to the screw forward movement speed. The valve closing operation speed is different from an initial speed of the injection filling speed, and the operation time thereof is set to the time necessary for moving the injection screw by a distance capable of performing the valve closing after the end of metering. The valve closing is performed with the set operation speed and the set operation time.