Method for controlling the forward movement speed of the screw in an injection molding machine
US6835337B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 29, 2002 |
| Grant date | Dec 28, 2004 |
| Priority date | — |
| Expiry date | Jan 23, 2023 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C45/77
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
In the filling step, the forward movement speed of the screw is controlled in accordance with a predetermined speed pattern until the screw reaches a deceleration initiation point, LS4B. After the screw reaches LS4B, a deceleration step is started. In the deceleration step, the forward movement speed of the screw is controlled in a feedback manner such that the internal pressure of the mold reaches a predetermined target pressure. When the screw reaches a pressure holding initiation point, LS4 (or pressure holding initiation time, TR2), the pressure holding step is started. In the pressure holding step, the target pressure, which is a function of time, is changed with time in accordance with a program. When the operation goes to the pressure holding step, the set of PID coefficients within the feedback control loop are replaced by different set of PID coefficients.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.