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. 07, 1992
Filed:
Jul. 24, 1990
Masaaki Kumamura, Yokohama, JP;
Ryohei Inaba, Kawasaki, JP;
Yozo Tobo, Sagamihara, JP;
Hirofumi Sugawara, Yokohama, JP;
Tadanobu Miyazaki, Ushiku, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An injection molding apparatus includes an electrically driven injection apparatus in which a screw accommodated in a heating cylinder is driven by a motor. The injection apparatus includes a pressure detection device for detecting an injection pressure of the screw and a device for detecting a stroke of the screw. Speed control is first conducted until the preset packing rate which represents that a dwell process is almost started is obtained, and the remaining injection process and the dwell process are conducted using an output of the pressure detection device. If a volume of resin in the cylinder which is required to fill the cavity is obtained beforehand, a packing rate of the molding material in the cavity is obtained by detecting the screw stroke. A packing rate which represents that the dwell process is nearly started is preset, and speed control of the screw is conducted and the resin is thereby packed at a fixed injection rate until when that preset packing rate is obtained. In the remaining injection process and the subsequent dwell process, a desired screw thrust is obtained using the output of the pressure detection device which detects the injection pressure of the screw.