Injection molding machine
US4349324A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 11, 1980 |
| Grant date | Sep 14, 1982 |
| Priority date | — |
| Expiry date | Jul 11, 2000 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2045/776
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An injection molding machine, comprises, an injection piston which is hydraulically actuated during programmed injection and dwell pressure phases. During a speed-controlled injection phase I, the pressure in a tool or mold cavity is measured and monitored. As soon as the pressure reaches an initial desired value, a pressure surge-free switching to the dwell pressure phase II is effected. During the dwell pressure phase, the pressure in the tool cavity is controlled and a pressure in a hydraulic cylinder for moving the injection piston is measured and monitored. A switch signal is produced from the tool pressure and the hydraulic pressure, by means of which a switching to a solidification phase III is effected without causing pressure surges. The actual pressure value at the instant of switching serves as the initial desired value for the solidification phase III. The hydraulic pressure is controlled during this phase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.