Two-fluid device for electroerosion

An electroerosion machining method, the method comprising:

• driving an electrode assembly comprising a plurality of tubular electrodes towards a workpiece;
• supplying an electrical current between the electrode assembly and the workpiece while feeding a first working fluid from a first fluid supply and a second working fluid from a second fluid supply through a gap defined therebetween;
• and
• performing electrical discharge machining (ED), pulsed electrochemical machining (PEC), or a combination thereof,
• wherein the first working fluid has a resistivity from about 0.05 MΩ·cm to about 1.5 MΩ·cm and the second working fluid has a resistivity from about 2 MΩ·cm to about 10 MΩ·cm.

An electroerosion drilling device comprising:

• a first fluid supply containing a first working fluid having a resistivity from about 0.05 MΩ·cm to about 1.5 MΩ·cm;
• a second fluid supply containing a second working fluid having a resistivity from about 2 MΩ·cm to about 10 MΩ·cm;
• an electrode assembly defining a central axis, the electrode assembly comprising
• a central tubular electrode extending along the central axis and defining a central conduit in fluid communication with the second fluid supply, wherein the central conduit is open toward a distal end of the electrode assembly,
• a plurality of peripheral tubular electrodes arranged around the central tubular electrode, the plurality of peripheral tubular electrodes defining a plurality of peripheral conduits in fluid communication with the second fluid supply, wherein the plurality of peripheral conduits are open toward the distal end of the electrode assembly, and
• an outer tubular cover at least partially encircling the central tubular electrode and the plurality of peripheral tubular electrodes, the outer tubular cover defining an interior conduit in fluid communication with the first fluid supply, wherein the interior conduit is open toward the distal end of the electrode assembly;
• a power supply electrically coupled to the electrode assembly for powering the electrode assembly;
• a working apparatus operable to rotate the electrode assembly about the central axis and to advance the rotating electrode assembly along the central axis into a workpiece positioned at the distal end of the electrode assembly for drilling the workpiece by electroerosion;
• and
• a control system operable to control the electrical power supplied by the power supply and to control both the rotation and the advance of the electrode assembly by the working apparatus.

An electroerosion milling device comprising:

• a first fluid supply containing a first working fluid having a resistivity from about 0.05 MΩ·cm to about 1.5 MΩ·cm;
• a second fluid supply containing a second working fluid having a resistivity from about 2 MΩ·cm to about 10 MΩ·cm;
• an electrode assembly defining a central axis, the electrode assembly comprising
• a solid central electrode extending along the central axis,
• a plurality of peripheral tubular electrodes arranged around the central electrode, the plurality of peripheral tubular electrodes defining a plurality of peripheral conduits in fluid communication with the first fluid supply, wherein the plurality of peripheral conduits are open toward the distal end of the electrode assembly, and
• an outer tubular cover at least partially encircling the central electrode and the plurality of peripheral tubular electrodes, the outer tubular cover defining an interior conduit in fluid communication with the second fluid supply, wherein the interior conduit is open toward the distal end of the electrode assembly;
• a power supply electrically coupled to the electrode assembly for powering the electrode assembly;
• a working apparatus operable to rotate the electrode assembly about the central axis and to advance the rotating electrode assembly along at least one direction that is perpendicular to the central axis while engaged in a workpiece positioned at the distal end of the electrode assembly for milling the workpiece by electroerosion;
• and
• a control system operable to control the electrical power supplied by the power supply and to control both the rotation and the advance of the electrode assembly by the working apparatus.