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:
May. 25, 1999
Filed:
Oct. 09, 1997
Tsuyoshi Arai, Nagano, JP;
Takayu Yamazaki, Nagano, JP;
Nissei Plastic Industrial Co., Ltd, Nagano-Ken, JP;
Abstract
A servo valve is connected to a hydraulic cylinder for driving a movable body for shifting. A control signal is applied from a controller to the servo motor for controlling speed of the movable body in an injection molding machine. Control is performed in such a manner that open-loop control of a speed is performed by applying a control signal on the basis of a speed command value to the servo motor in a shifting zone of the movable body including an acceleration region. Closed-loop control is performed by applying a control signal (derived on the basis of a deviation between a speed detection valve and speed command value), to the servo valve in a shifting zone of the movable body including a decelerating region. By such a control method, in which the shifting zone including the accelerating region and the shifting zone including the decelerating region are separated, stability of control, necessary response characteristics, and precision can be maintained in a shifting range.