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:
Apr. 16, 2002
Filed:
Jul. 01, 1999
Hitoshi Hara, Funabashi, JP;
Sumitomo Heavy Industries, LTD, Tokyo, JP;
Abstract
In a back pressure control apparatus for controlling back pressure in an injection molding machine comprising an injection device which comprises a heating cylinder, a screw, and an injection actuator and which is provided with a back pressure detector for producing a pressure detected signal and with a screw position detector for producing a screw position detected signal, the back pressure control apparatus comprises a level setting section for setting a back pressure control level with respect to back pressure. A sharpness selecting section selects, as a selected sharpness, one of a plurality of sharpnesses in transition up to a maximum back pressure command value. On the basis of the back pressure control level, a determining section determines a back pressure pattern having a variable back pressure command value which continuously changes with respect to a retreat position of the screw. The back pressure pattern has a mountain-shaped portion defined by the selected sharpness. Responsive to the pressure detected signal and the screw position detected signal, a controller controls the back pressure in accordance with the back pressure pattern by means of the injection actuator.