Micromachining aerofoil components

Abstract

The method is suitable for the micromachining of accurately aligned holes in the aerofoil surface of a component such as a jet engine turbine blade or vane which comprises a ground anchorage portion and a cast aerofoil portion. The method uses a micromachining apparatus which is pre-programmed to machine holes in the aerofoil surface when that surface is in a predefined reference position and orientation in the apparatus. Initially the component is mounted in the micromachining apparatus by means of its anchorage portion. At least one probe is then moved into contact with the surface of the cast aerofoil portion to derive the positions of selected points on that aerofoil portion. From the derived position data, angular and linear offset data may be calculated to define the deviation of that cast aerofoil portion from the reference position and orientation defined in the computer memory of the micromachining apparatus. That angular and linear offset data is applied to the computer program resident in the micromachining apparatus to control the movement of the drilling head relative to the aerofoil surface and to machine the air holes in the aerofoil surface without having to remove the component from the apparatus.

Dependencies are inferred from the claim text.