Open loop pressure control for injection molding
US7766647B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 8, 2009 |
| Grant date | Aug 3, 2010 |
| Priority date | — |
| Expiry date | Jul 8, 2029 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2045/306
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An injection molding system is disclosed having a self-regulating valve for balancing melt flow. The self-regulating valve includes a control rod configured to balance the melt flow rate through a hot runner system. The self-regulating valve reacts to an injection or melt pressure within the hot runner system and a pre-set force provided by an external force device. The self-regulating valve is an open-loop system as it requires neither a measurement of pressure by a sensor nor feedback from a processor in order to regulate the melt flow. The self-regulating valve mechanically reacts to changes in melt pressure on control surfaces thereof by “bobbing” upwards/downwards to decrease/increase the melt flow accordingly. The self-regulating valve compensates for conditions that affect melt pressure, such as an increase/decrease in melt viscosity, changes in melt temperature, and/or mold cavity size without the use of a processing device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.