CNC五軸切削曲面等扇形高刀具路徑規劃

Iso-scallop Height Tool Path Planning for CNC 5-axis Surface Machining

王信超(Shin-Chau Wang)

指導教授 ： 蔡哲雄

國立臺北科技大學/機電學院/製造科技研究所/碩士(2009年)

摘要

本文以球形端銑刀及刀軸以固定傾角的方式，建立曲面切削之五軸加工的刀具路徑，提出一套整合等扇形高法及弦高誤差監測法，適當的調整刀具間距來規劃刀具的切削路徑，使得加工曲面上的扇形高能夠一致，並且在滿足弦高誤差下，以較少的刀具路徑點數計算出刀具路徑。因此，此刀具路徑規劃法能降低加工時間並且控制切削曲面的粗糙度均勻及切削面之幾何形狀的精度。
本文首先說明參數曲面的建構以及如何計算出相鄰的兩切削路徑的方法，以建立出初步的等扇形高之刀具路徑。接著說明刀具沿刀具路徑點移動切削過程中所造成的弦高誤差之控制，以求得適當的切削點步距，確定步距後再進行刀軸方位的調整。整合這兩種方法使產生的刀具路徑能使兩刀具路徑間的扇形高及切削的弦高誤差在容許值內。本文方法用Matlab撰寫程式執行，以 Bezier Surface 的曲面精加工為例，應用 Unigraphics CAD/CAM 系統來測試本文方法的結果與正確性，並證實確實可行。

關鍵字

五軸刀具路徑規劃 ； 等扇形高 ； 弦高誤差

並列摘要

In this paper, an algorithm of iso-scallop height tool path planning with tilting cutter-axis for sculptured surface 5-axis machining was developed. The chord error in each forward step cutting on each tool path was also detected in present algorithm. First, this paper illustrates the tool paths spacing method which keeping the scallop height uniformly between two adjacent tool paths, and by the way we can construct the initial tool paths planning for sculptured surface 5-axis machining. Second, we explain the chord error detection method along each tool path point which influence the cutting accuracy of the sculptured surface. Third, a suitable tilting angle of the cutting tool axis was performed for each cutting path point After integrating the above methods, we can generate tool cutting paths with iso-scallop height and satisfied surface accuracy for the sculptured surface machining.. In this study, we develop a Matlab program to implement present 5-axis tool path planning algorithm. A example of Bezier surface 5-axis machining was carried out and applied the UG CAD/CAM system to demonstrate the validity and practicability of this algorithm. The present 5-axis tool path planning method is suitable to generate a Zig or Zig-Zag cutting paths pattern for precisely sculptured surface machining.

並列關鍵字

5-axis tool path planning ； iso-scallop height ； chord error

參考文獻

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