| 摘要 |
PURPOSE:To lessen unevenness of properties without being affected by uneven injection conditions by carrying out gate cut when the resin pressure in a cavity, the resin pressure in injection molding or the working hydraulic pressure in injection molding or the working hydraulic pressure driving a screw of an injection molding machine become a given value. CONSTITUTION:The resin pressure in a cavity rises, after starting injection of molten resin into a cavity 10. The resin pressure in said cavity is measured continuously by a pressure sensor 21 and its signal output is amplified by an amplifier 22 and transmitted to a computing element 23. The computing element 23 compares and computes a resin pressure signal in the cavity and said set value signal from a setting device 24, and when the resin pressure iun the cavity conforms with the set value, a drive signal of a gate cut cylinder 9 is transmitted to a selector valve 25. A valve 252 is moved in the left direction by said arrangement to transfer the pressurized oil from a hydraulic device 26 to the gate cylinder 9 through an oil circuit 262, a gate cut punch 8 is projected to the side of a fixed mold 2 for carrying out gate cut, punch a central section of a molded product and form a center hole. |
