Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/2765
標題: 切割B-spline自由曲面精切削路徑規劃
Automatic finish cut path generation for trimmed freeform surface
作者: 林鴻齊
關鍵字: 刀具路徑規劃;B-spline 自由曲面;切割元件;切割曲面;精切
出版社: 機械工程學系
摘要: 
本論文在於發展出一個穩定、有效率的方法,將一個已經存在之B-spline自由曲面的球銑刀精切削路徑資料作切割處理。在不影響原本之CAD模型資料結構下,重新規劃及產生切割後的切削路徑。
對於一個B-spline自由曲面模型,現已經可以產生合乎需求的球銑刀精切削刀具路徑。而對於切割此自由曲面精切削刀具路徑,本文中將使用平面及空心圓筒面作為切割元件。切割元件先將一已存在之B-spline自由曲面之刀具接觸資料(CC data)做切割處理。此處理是將切割元件做偏置,以產生新的曲面邊界限制,以規劃產生新的刀具路徑。把已產生之刀具接觸點的鏈結資料結構與切割元件利用簡單的相交運算法則,產生新的資料結構。再以非加工區資料移除運算法則,將不要的資料從鏈結之中移除,得到最後的CC data 。再將這些CC資料做偏置轉成刀具路徑資料(CL data),並轉成可以做加工用的NC 程式 。
切割自由曲面刀具路徑在本文中將作為不同之加工要求的應用;可用於切割一般模穴或模型的刀具路徑,或者切割電極模型的銑削刀具路徑。

The object of this thesis is to develop a method which trim ball-end mill cutting paths for an existing freeform surface. Without changing the original CAD data model, a new set of trimmed cutting paths is expected to be generated.
For a B-spline surface model, there exist methods to generate qualified cutting paths for ball ended mills. For such a freeform surface model, planes and cylinders are used trimming elements for trimmed path generation. Firstly, trimming elements are used to trim existing cutter contact data (CC data). Such processing is to offset trimming element to generate new boundary limits in order to generate new tool paths. Using simple intersection computation, new data structure is generated from linked data of cutter contact points and trimming points. Subsequently, redundant data of non-machining area are removed from linked lists, and final CC data are obtained. Those CC data are offset to become CL data, then NC code for machining can be obtained.
The operation for trimming tool paths of freeform surfaces is useful for trimming on die cavitipplication. The trimming of cutting paths for EDM electrode is another application.
URI: http://hdl.handle.net/11455/2765
Appears in Collections:機械工程學系所

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