Apparatus and method to machine holes
AssigneeSiemens Aktiengesellschaft
InventorAndreas Graichen
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Abstract
The present invention relates to an apparatus for machining holes, especially to machine holes in a surface of a coated gas turbine airfoil, which apparatus comprises a laser device for laser drilling and an electrode for electrical discharge machining. Further the invention relates to a method to machine a hole into a coated surface with an apparatus of the incipiently mentioned type. Known methods make use of a machine with separate machine heads for laser drilling and electrical discharge machining. By combining these two devices in one machine head the invention gives the possibility to save time and obtain very accurate results.
Claims12
An apparatus for machining holes in a surface of a coated gas turbine airfoil, comprising:
- a laser device for laser drilling having an emission module, the emission module comprising an emission surface to emit the laser beam in a defined direction;
- and
- an electrode operable for carrying out electrical discharge machining on the surface, wherein the emission module and at least a part of the electrode are attached to one machine head in a fixed spatial relation to each other, such that the emission direction of the laser has a constant spatial offset with respect to the electrode, and
- wherein the emission surface of the emission module is ring shaped and the part of the electrode is coaxially disposed within the ring and facing the surface to be machined, wherein the part of the electrode is movable within the emission module.
A method to make a hole into a coated surface using a single machine head that incorporates a laser emission module and an electrode for electrical discharge machining, the laser emission module having a ring-shaped emission surface, wherein the electrode is disposed in a coaxial and movable manner within the emission module, the method comprising:
- removing a portion of the surface coating by a laser beam, wherein the laser beam is directed to the surface by the emission module, wherein the electrode is withdrawn from the surface during the coating removal;
- switching off the laser after removal of the coating layer;
- moving the electrode within the emission module for positioning the electrode adjacent to the surface and above the area of the removed coating, without moving the machine head;
- and
- machining the hole by electrical discharge machining.
Dependencies are inferred from the claim text.