Tool path modification based on deformation mapping relationship for the adaptive machining of aero-engine blade

The machining efficiency of blade plays an extremely important role in the aero-engine manufacture, especially demanding on the adaptive machining for near-net shape blade. However, the deviation between the actual blade and nominal model can raise serious problems for NC tool path generation. There is a significant demand for directly modifying the nominal tool path based on measurement data in on-site adaptive machining condition. To this end, this paper proposes a tool path direct modification method based on deformation mapping relationship. Decomposing complex blade deformation calculation into the establishment of mapping relationship, including rigid and non-rigid deformation. And parametric modifying each tool axis and center points based on the mapping between tool path contact points and measurement data. The proposed method avoids the tedious model reconstruction process, the topological discontinuity of modified tool path caused by the misaligned error, and the insufficient modification information of tool axis caused by single displacement deformation. A test case of near-net shape blade is given to demonstrate the effectiveness and convenience of the proposed method, and these results shows that the contour error of the adaptive machining area is less than 0.031 mm, and the machining junction of the adaptive machining area and net-shape area could possess a smooth blending.