TW-electroerosion machines with double-floating nozzle assemblies

摘要

An inner movable nozzle and an outer movable nozzle are slidably supported by a hollow base member having a first and a second internal fluid passage flooded with a pressurized machining liquid medium in a first and a second inlet flow, respectively. The inner nozzle is constituted by a first hollow body surrounding a traveling electrode and ending with an outlet portion forming a first annular face adjacent the workpiece and defining a principal nozzle orifice for discharging the liquid medium of the first flow about the electrode. The hollow body is movably supported by the base member so as to be thrusted outwards thereof to urge the outlet portion towards engagement with the workpiece against pressure in constituted fluid passages created outside the principal nozzle orifice and defined with the workpiece. The outer movable nozzle is constituted by a second hollow body surrounding the first hollow body so to be movable independently thereof and ending with an outlet portion forming a second annular face adjacent the workpiece and defining with the first-mentioned outlet portion an annular, auxiliary nozzle orifice for discharging the liquid medium of the second inlet flow about the liquid medium being discharged through the principal nozzle orifice. The second hollow body is supported by the base member so as to be thrustable outwards thereof to urge the second annular face towards engagement with the workpiece against pressure of the discharged liquid medium flowing between the second annular face and the workpiece.