整合刀具動態與切削體素模型於五軸加工與顫振預測之技術開發

Abstract

近年來隨著製造業不斷的發展，銑削技術在加工領域中扮演著關鍵的角色，並持續取得重要的進展。特別是五軸加工技術的發展，使我們能夠實現更複雜的工件形狀，同時也對工件的精度有更高的要求。因此能夠精確的模擬切削力及切削狀態顯得越發重要。在加工過程中，為了確保尺寸精度以及切削狀態的穩定，仰賴現場工程人員透過聲音及振動情形即時對於切削參數進行調整來保護機台及工件免於切削顫振，即時調整切削參數不僅耗時費力，且改善效果也難以被量化，此外當現場工作人員感受到顫振發生時，刀具以及工件已受到破壞，為使切削參數的調整有參考依據。本研究透過切削過程的訊號模擬，在實際加工前預測刀軸切削顫振情形，並可依據模擬結果提前對於切削參數進行調整。 本研究利用八元樹法建立實體模型，以UG(Siemens Unigraphics)進行路徑規劃及繪圖，並將規劃路徑及圖檔輸出成CLSF檔(Cutter Location Source File)及STL(STereoLithography)零件檔，其中 STL 檔為待切削材料用於建立體素模型，CLSF 檔包含切削路徑、進給率、刀軸向量、轉速等切削參數，以敲擊實驗對於刀具進行建模得到系統動態模型，並加入到切削力模型，兩種檔案及系統動態模型皆匯入Matlab 軟體進行模擬。切削力模擬過程中，記錄由動態模型造成之刀具位移，接著將位移回授至切削力模型進行計算，模擬結果可獲得整個切削路徑刀具在X、Y方向的位移量，藉此了解切削顫振情形。本論文最終針對不同切削條件進行顫振模擬，可供業界做為調整切削參數之可靠依據。

In recent years, with the continuous development of the manufacturing industry, milling technology has played a key role in the field of machining and has made significant progress. Especially with the development of five-axis machining technology, it has become possible to achieve more complex workpiece shapes, and there are higher requirements for workpiece precision. Therefore, the ability to accurately simulate cutting forces and cutting conditions has become increasingly important. During the machining process, to ensure dimensional accuracy and stability of the cutting conditions, on-site engineers rely on sound and vibration to adjust cutting parameters in real-time to protect the machine and workpiece from chatter. However, real-time adjustments are time-consuming and labor-intensive, and the improvement effects are difficult to quantify. Additionally, when on-site workers notice chatter, the tool and workpiece may already be damaged. To provide a reference for adjusting cutting parameters, this study simulates the signals during the cutting process to predict the chatter of the tool axis before actual machining, allowing for preemptive adjustment of cutting parameters based on the simulation results. In this study, an octree method is used to establish a solid model, with path planning and drawing performed using UG (Siemens Unigraphics). The planned path and drawings are exported as CLSF (Cutter Location Source File) and STL (STereoLithography) part files. The STL file represents the material to be machined for voxel model creation, while the CLSF file contains cutting paths, feed rates, tool axis vectors, spindle speeds, and other cutting parameters. A dynamic system model is obtained through impact testing on the tool, which is incorporated into the cutting force model. Both file types and the system dynamic model are imported into Matlab for simulation. During the cutting force simulation process, the tool displacement caused by the dynamic model is recorded and then feed back into the cutting force model for calculation. The simulation results provide the displacement of the tool in the X and Y directions along the entire cutting path, enabling an understanding of the chatter conditions. This thesis ultimately conducts chatter simulations under different cutting conditions, providing the industry with a reliable basis for adjusting cutting parameters.