複合曲面加工之刀具路徑必須能正確的通過相互連接之曲面,複合曲面由於兩相連之曲面在交界處的曲面法向量或曲率不同,要產生一個無過切的加工刀具路徑並不容易。本文以球端銑刀對複合曲面三軸銑削加工建構一套在刀具中心曲面進行網格所產生的刀具路徑規劃法,本文方法可透過預設容差值設定來控制加工面的扇形餘料高及弦高誤差之幾何精度要求。本文以四個複合曲面加工,應用本文刀具路徑建構法產生之刀具路徑數據資料匯入CAD/CAM系統進行模擬及輸出NC碼由CNC銑床進行切削加工。結果顯示本文複合曲面刀具路徑規劃確實可行。
In a complex surface machining, the planned tool path must correctly pass through the connected surface patches. Because the surface normal vectors or curvatures are different from the border of two connected surface patches, it is not easy to generate a machining tool path without any gouging situation for complex surface machining. In this paper, a ball-end mill tool path generation method for a complex surface machining was developed by using a meshing algorithm on the offset surface of tool center. In present tool path generation method, both scallop height and chord error of the machined surface can be controlled by a preset error tolerance to attain the requirement of the geometric accuracy. Four examples of complex surface machining were performed by using present method and then the calculated cutter location data was input into CAD/CAM systems for cutting simulateion and generating the NC-code for practical machining on CNC milling machine The results show that the proposed tool path planning method is actually feasible.