五軸加工機目前已廣泛應用於切削複雜零組件及曲面,尤其是壓縮機、渦輪機的葉輪切削,是目前高附加價值元件加工的主要利器。五軸同動的加工程式難以用人工手寫的方式完成,必須經由CAD/CAM系統及後處理程式,才能轉換成五軸加工機加工所需要的程式資料。通常後處理程式係將CAD/CAM系統所產生的刀具路徑檔案轉換為五軸加工機接受的程式碼,是電腦輔助製程規劃與數控(NC)加工間的重要介面。但ㄧ般CAD/CAM套裝軟體的後處理有其專用性,應用受限,為能發展新的五軸加工法及實作試驗,必須建立五軸加工的後處理程式。 本文以具有X,Y,Z,B,C軸工作台傾斜型的五軸工具機為例,應用Matlab程式建構一套專屬的後處理程式。本文應用齊次轉換矩陣的方法,建立工件座標系與刀具座標系間的位置與方位空間關係,利用修正型D-H矩陣來計算刀具實際的五軸運動值。為能驗證本文建構的後處理程式的正確性,本文以若干五軸加工的實例,包括Unigraphics CAD/CAM系統之五軸加工法,應用本文後處理程式轉換五軸加工程式,並經實作加工確認無誤。本程式可應用於本機台構型之五軸加工程式後處理。在規劃出五軸加工的刀具位置與刀軸方位後,本後處理程式即可正確的產出各運動軸加工指令。
5-axis machines have already applied to cut the complicated part and surface extensively, especially the impellers cutting of the compressor and turbine. And it is an efficient machine tool of the high value-added component machining at present. It is difficult to complete the 5-axis part program in handwritten way. The CAD/CAM systems generated cutter location data have to be changed into the one that is acceptable to 5-axis machine tool through the postprocessor. The postprocessor is the important interface in computer aided process planning and NC (numerical control) machining because it is used to change cutter location file designed by CAD/CAM systems into the NC-code that is acceptable to 5-axis machine tools. But generally the postprocessor module in CAD/CAM is specialized that it can’t apply to other machines. In order to develop a new 5-axis machining process and do an examination, we have to set up a 5-axis postprocessor. This paper constructed the postprocessor which is suitable for the 5-axis machine (X, Y, Z, B, and C axes), table-tilting type with Matlab. In this program process, we use the method of homogenous transformation matrix to describe the relation between workpiece coordinate system and cutting tool coordinate system and use the modified D-H matrix to calculate 5-axis real kinematics values. In order to prove the postprocessor, we have taken 5-axis milling operations in Unigraphics CAD/CAM system as verification examples and transformed the tool paths into 5-axis NC-code. The result is exactly. The developed postprocessor can apply to transforming part program of present 5-axis machine. After planning the tool path (tool location and tool axis orientation), the postprocessor can produce NC program correctly.