The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 15, 1999
Filed:
Nov. 27, 1996
ProControl AG, Flawil, CH;
Abstract
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.