In the injection molding machine and the injection molding machine the closing device and the ejection device

摘要

PURPOSE:To make the feed flow rate and the discharge flow rate to a hydraulic pump equal by a method wherein an auxiliary mold clamping cylinder is arranged radially outward a mold clamping ram and, at the same time, the piston rod of the auxiliary cylinder is joined to the mold clamping ram so as to form a closed circuit between respective cylinders and the hydraulic pump. CONSTITUTION:At mold closing, oil, the amount of which is larger than the amount introduced to the small areal pressure receiving face (a) side, is discharged from the large areal pressure receiving face (b) side in a cylinder 1. The discharged oil is not sent back as it is to a suction line T but poured to the large areal pressure receiving face (d) side of an auxiliary cylinder 5. Oil, which is discharged from the small areal pressure receiving face (c) side, is sent back to the suction line T. In addition, since the areal relationships between the respective pressure receiving faces is set to be a=c and b=d, the imbalance between the feed flow rate and the discharge flow rate in the cylinder l can be absorbed in the auxiliary tank 5 or the amount of the oil introduced to the small areal pressure receiving face (a) side in the cylinder 1 becomes equal to the amount of the oil discharged from the small areal pressure receiving face (c) side in the auxiliary cylinder 5, resulting in allowing to realize a closed circuit without trouble.