| 摘要 |
<p>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 (12) and a cast aerofoil portion (10). The method uses a laser machining apparatus which is preprogrammed to machine holes in the aerofoil surface (10) when that surface (10) is in a predefined reference position and orientation in the apparatus. Initially the component is mounted in the laser machining apparatus by means of its anchorage portion (12). At least one probe (30, 32, 34, 36) is then moved over the surface of the cast aerofoil portion (10) to derive the positions of selected points (P<SB>1</SB>, P<SB>2,</SB> P<SB>3</SB>, P<SB>4</SB>, P<SB>5</SB> and P<SB>6</SB>) on that aerofoil portion (10). From the derived position data, angular and linear offset data may be calculated to define the deviation of that cast aerofoil portion (10) from the reference position and orientation defined in the computer memory of the laser machining apparatus. That angular and linear offset data is applied to the computer program resident in the laser machining apparatus to control the movement of the laser 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.</p> |
