Vickers, Inc.

Procontrol Ag

Hugo Blochlinger

Bruno Stillhard

Ronald Siegrist

A method is disclosed for controlling an injection molding machine of the type having an injection screw drivable for axial movement within an extrusion cylinder by a drive-controlled servo motor through a mechanical transmission, to provide a filling phase, a dwell phase, and a plasticization phase, the servo motor having a velocity command signal input connection, and the molding machine having sensors for screw position and injection pressure. The method includes the steps of presetting desired values for at least one of the injection pressure and the screw position; sensing the respective one of the corresponding actual injection pressure and actual screw position; and transmitting non-zero velocity command signals to the drive-controlled servo motor during at least the plasticization phase, and preferably also the filling and dwell phases, to move the injection screw within the cylinder. The velocity command signals are calculated as a function of a deviation of the respective one of the actual injection pressure and the actual screw position from the respective preset desired value, preferably using a linear functional relation during small deviation values, and a non-linear functional relation for large deviation values, to improve stability.

Process for injection molding machine with electric drives

A drive control apparatus for controlling a plurality of control variables of at least one electrically powered axle of a processing machine, such as an injection molding machine. Multivariable control means including internal signal processing and date storage means for an open and closed-loop control of phase angle, current input and velocity are dominating process computer means for a lag-free control of the control variables.

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Flawil, Switzerland

Hugo Blochlinger