五軸加工刀具路徑選擇與加工過程優化之研究

Abstract

隨著五軸加工技術在機械製造領域中的廣泛應用與智慧製造的發展，目前關於五軸加工的研究工作多旨在自動化解決加工時常見的問題，從而減少人員的工作內容並提高加工過程的可控制性。近年來許多研究專注於刀具軸向的調整，以此優化加工中的物理量、降低加工時間、提升工件表面品質，然而對於應以何種依據決定刀具路徑策略仍然沒有定論，因此本研究欲討論常見圖形特徵中合適的刀具路徑策略，未來可將其結合徵辨識技術，自動化給出刀具路徑。 本研究針對五軸加工中常見的圖形特徵規劃其常用之刀具路徑策略，從加工時間的方面衡量其優劣。針對床台旋轉型五軸加工之A軸極限位置的換解問題提供兩種改善方案，一是給定初始刀具角度從而避開A軸的極限位置，二是後處理器中加入演算法，在經過A軸原點時判斷下一加工程式段落應選擇正解或是負解。基於給定扇形殘高與弦高誤差與曲面曲率計算切削步長及道次間距，提供CAM軟體流線加工工法參數設定之參考，以改善由刀尖點路徑長度不平均所導致加工表面拉絲紋的問題。

With the widespread application of five-axis machining technology in the field of mechanical manufacturing and the development of intelligent manufacturing, current research on five-axis machining primarily aims to automate the resolution of common machining problems. This reduces manual workload and improves the controllability of the machining process. Recent studies have focused on adjusting the tool axis to optimize physical parameters, reduce machining time, and enhance workpiece surface quality. However, there is still no consensus on the criteria for determining toolpath strategies. Therefore, this study aims to discuss suitable tool path strategies for common geometric features, which can be combined with feature recognition technology in the future to automatically generate toolpaths. This study focuses on planning common toolpath strategies for typical geometric features in five-axis machining and evaluates their effectiveness in terms of machining time. To address the phase reverse issue of the A-axis reaching its limit position in table-rotary type five-axis machining, two improvement solutions are proposed: (1) by given initial tool orientation to avoid the A-axis limit position, and (2) incorporating an algorithm into the post-processor to determine whether the next machining segment should select the positive or negative solution when passing through the A-axis zero point. Based on given scallop height, chord error and surface curvature, the cutting step length and stepover are calculated to provide reference parameters for streamline machining in CAM software. This approach aims to mitigate surface streaking issues caused by uneven cutter contact distance.