Measurement control method of an injection molding machine

A measurement control method for an injection molding machine in which a measurement is performed by rotating a screw, comprising the following steps:

• setting a first ending target position corresponding to a measurement ending position,
• setting a rotation rate pattern to rotate the screw,
• retracting the screw at a predetermined retraction rate pattern wherein the retraction is pre-set,
• setting the first ending target position at a time of measurement of a remaining rotation rate pattern to stop the screw rotation at said first ending target position is predicted by a calculation based on a screw position detected at every specified time interval,
• controlling the screw rotation to the first ending target position based on the remaining rotation rate pattern and thereafter performing a reverse rotation to apply a back pressure to the screw,
• stopping a screw retraction at a second ending target position predicated by a calculation based on a screw retraction rate detected at every specified time interval,
• controlling the screw based on the retraction rate pattern to retract to said second ending target position,
• stopping the rotation and retraction of the screw when the screw reaches said second ending target position, and
• subsequently controlling the screw to reverse rotate by a preset constant amount of rotation while controlling the position of the screw to cause a depressurization.