Electrohydraulic control of a die casting machine
US5289388A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 21, 1989 |
| Grant date | Feb 22, 1994 |
| Priority date | — |
| Expiry date | Apr 21, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B2219/45244
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
In a die casting machine that includes a shot cylinder having a ram for injecting metal into a die cavity, an electrohydraulic system for controlling operation of the shot cylinder includes an actuator coupled to the shot cylinder ram. A valve supplies hydraulic fluid to the actuator cylinder as a function of valve control signals. Microprocessor-based digital control electronics includes memory for storing a desired ram velocity profile as an incremental function of ram position. The control circuitry is responsive to signals from a sensor coupled to the actuator, indicative of position at the ram, for retrieving corresponding velocity signals from memory and supplying control signals to the valve as a function of such profile velocity signals. The control circuitry further includes facility for adjusting impact of the shot cylinder ram at the end of a cavity-filling stroke as a function of ram and actuator position and/or pressure, independently of the velocity/position profile, to reduce separation and flashing at the die cavity, and to reduce impact wear and fatigue on the overall die casting machine. A keyboard and associated operator display provide operator programmability a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.