Injection mold using screw thrust control
US5102587A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 1990 |
| Grant date | Apr 7, 1992 |
| Priority date | — |
| Expiry date | Jul 24, 2010 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C45/77
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
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 sc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.