CONTROL OF MOLDING DIE CLAMPING DEVICE

PROBLEM TO BE SOLVED: To shorten a molding cycle by starting the thrusting-out of an ejector pin by moving it forward after the start of opening a molding die and starting the closing of the die before checking the return of the ejector pin following the initiation of the backward movement of the ejector pin simultaneously with the end of the thrusting-out action. SOLUTION: A suspension step is started (t22) at the end of a cooling step (t21) and is completed (t23). On the other hand, a molding die opening step (t24) simultaneously with the initiation of the suspension step and the die opening step is ended (t25). Further, after starting the opening of the molding die, the thrusting-out of the ejector pin is commenced (t27), and if the thrusting-out action is ended (t28), the ejector pin is moved backward. If it is confirmed by a position sensor that the ejector pin is already back to its home position, a return confirming signal is sent to a control part (t29). If the closing of the molding die is started, the control part begins clocking (t26), and interprets whether the return confirming signal is received (t30) after the lapse of a monitoring time T. If the signal is received, the control part continues the closing of the die and if the signal is not received, the closing of the die is stopped.