| 摘要 |
A reconfigurable variable blank-holder force system (and method) for producing sheet metal stampings comprises a portable hydraulic unit, controlled by a digital control system and a knowledge-based expert system to enable reconfigurability and an easy transition from the try-out stage to production. The knowledge-base has a hierarchical structure and includes stored information about part geometry, material properties and press parameters. The expert system enables an operator to determine optimal blank-holder forces, and to fine-tune through a graphical interface unit. The optimal blank-holder forces are generated by hydraulic force actuators, using a controller running a nonlinear algorithm that accounts for valve nonlinearities, variable flow-rate and numbers of operational cylinders. The portable hydraulic unit preferably comprises hydraulic cylinders with quick disconnect hoses, a manifold, servo-valves and a pump unit. A structured method to utilize this system to produce sheet metal stampings is also described. An article embodying the method is included.
|
