Patent ID: 8244397
Filing Date: 2012-08-14
Classification: B29C

Abstract:
1. A method for controlling a mold clamping device which performs mold clamping control by driving a mold clamping cylinder by a hydraulic pump which can control a discharge control rate by variably controlling the number of revolutions of a drive motor, the method comprising: preliminarily setting a predetermined speed control pattern including, at least, a mold closing section in which mold closing is performed at a predetermined mold closing speed, a deceleration section in which the speed is gradually decelerated from an end point of the mold closing section toward a virtual stop position, and a low-pressure low-speed section for which a predetermined mold clamping-transition speed is set before the virtual stop position; in a mold clamping process, in the mold closing section, performing mold closing control at the mold closing speed, and sequentially forecasting, based on a current mold closing speed and a current mold closing position, which are both detected, a deceleration starting position of the deceleration section where a current mold closing speed becomes a zero (O) at the virtual stop position, at each predetermined time interval by calculation; starting the deceleration section upon reaching the deceleration starting position, and in the deceleration section, obtaining, based on the detected current mold closing position, a speed command value corresponding to the speed control pattern sequentially by calculation, and according to the speed command value, performing deceleration control; and upon reaching the mold clamping-transition speed, performing predetermined mold clamping processing via the low-pressure low-speed section, wherein a sub-tank is attached to the mold clamping cylinder, and in the mold closing section and the deceleration section, control in which the sub-tank is connected to a rear oil chamber of the mold clamping cylinder so as for hydraulic oil in the sub-tank to be flowed into the rear oil chamber, is performed.