球形端銑刀銑削曲面之刀具路徑規劃

Tool Paths Planning for Sculptured Surface Finishing Using Ball End Mill

劉華樑(Hwa-Liang Liu)

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(2008年)

https://doi.org/10.6841/NTUT.2008.00612

摘要

CNC加工機廣泛使用在精密製造產業的加工，加工技術的重要性與日俱增。為提昇CNC加工技術之應用研究，本文針對球形端銑刀切削曲面之路徑規劃進行研究探討，提出一套整合等扇形高法和弦高誤差法來規劃刀具路徑，此刀具路徑規劃法，能控制切削曲面的粗糙度均勻及切削之幾何形狀的精度。
本文首先說明由曲面資料計算產生等扇形高之路徑間隔的方法，以獲得初步的刀具路徑。接著說明本文刀具沿刀具路徑點移動切削過程(短直線)造成弦高誤差的計算，以及誤差值過大自動增補路徑點的方法。整合這兩種方法使產生的刀具路徑能兼顧兩刀具路徑間維持等扇形高及切削的弦高誤差在容許值內。
本文並將這一套刀具路徑產生法用Matlab寫成程式，以Bezier Surface的曲面精加工為例，以及應用UG CAD/CAM系統來測試本文方法的結果與正確性。本文方法簡便，適合應用於產生Zig 或Zig-Zag的曲面精加工刀具路徑的定義，達成曲面加工粗度與精度控制。

關鍵字

等扇形高 ； 弦高誤差 ； 曲面精切削 ； 刀具路徑 ； 球形端銑刀

並列摘要

CNC machines are widely used for precision machining of various parts. For the application of CNC processing technology, this paper focuses on tool paths planning for sculptured surface finish cutting by using ball end mill. This paper proposes an algorithm of tool path planning by integrating both methods of iso-scallop height and chord error restriction. This plan can control the roughness uniformly on the machined surface and precisely geometric shape of the part.
Firstly, 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 cutting. Secondly, the chord error controlling method along each tool path will be explained, which determine the cutting accuracy of the sculptured surface. When detected chord error is over the preset tolerance between adjacent path points, the present algorithm will automatically insert path points to satisfy the accuracy requirement. After integrating the two methods, we can generate cutting tool paths with iso-scallop height and cutting accuracy.
In this study, we construct a Matlab program to implement present tool paths planning algorithm. An example of planning Bezier surface cutting paths was carried out and applied the UG CAD/CAM system to demonstrate the validity and practicability of this algorithm. Here we propose that tool paths planning method is more simple than the others, and it is suitable to generate Zig or Zig-Zag tool path patterns for precisely sculptured surface machining.

並列關鍵字

Iso-scallop height ； Chord error ； Sculptured surface finishing ； Tool paths ； Ball end mill

參考文獻

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