Electrical discharge machine with automatic filtering

摘要

An electrical discharge machine having an electrode and workpiece contained within a dielectric-filled machining tank for machining in response to the application of discharge current. One or more auxiliary tanks that contain additional dielectric fluid are connected to the machining tank by a plurality of fluid flow paths that contain various combinations of filters, valves and pumps. The filters may be of different filtering capacity for serving different machining operations, e.g., roughing and finishing. The operation of the valves to provide filtering appropriate to the current machining conditions is based on detected or predetermined machining conditions such as sludge grain diameter, fluid pressure, sludge quantity, electrode and workpiece material composition and discharge current levels.