- 學位論文
側銑切削不可展直紋曲面之尺寸誤差與避免過切研究
Study of Dimensional Error and Overcutting Avoidance for Undevelopable Ruled Surface Flank Milling
摘要
不可展直紋曲面由於形狀扭曲，常用於如離心式葉片曲面，因離心式葉片和葉片間在三維空間中會有Z方向的重疊，且葉片的二側面係屬直紋曲面(Ruled surface)設計，故葉片加工通常利用五軸加工機以五軸同動側銑的方式來加工，避免刀具與工件發生干涉及碰撞，側銑可提高材料移除率，並增加表面光平度，若應用端銑刀以五軸同動直接側銑不可展之葉片曲面將產生過切尺寸之誤差。本文針對不可展直紋曲面側銑切削提出切削規劃法，可以控制切削尺寸誤差量或避免過切情形發生。 本文首先提出一修正法，由本文的過切誤差估算法，將刀具移動方位做一適當的偏移量，以避免側銑過切的發生，增加側銑後產品的精度，本文方法透過Matlab程式撰寫不可展直紋曲面參數方程式資料，以本文提出之過切誤差法為輔，精確的計算出每個刀具路徑的刀端座標及刀具位置，並經由實例分析計算規劃出端銑刀五軸側銑不可展直紋曲面之刀具路徑，由Matlab獲得資料再經由CAD/CAM軟體模擬及在機台實際切削結果顯示，本文方法確能精確控制切削誤差或控制避免過切發生。本文方法可應用於葉輪之薄壁葉片切削加工，以控制葉片尺寸精度。
並列摘要
Undevelopable ruled surface shape distortions, so it is widely used in centrifugal blade surface, due to the centrifugal blades in the three-dimensional space there will be overlap of the Z direction, blades two sides is a ruled surface (Ruled surface) design, blade machining is usually 5-axis machining axis with fixed flank milling processing, to avoid the tool and work piece interference and collisions, flank milling can increase the material removal rate, and increase the surface smooth, if the application flank milling cutter axis with fixed direct flank milling of undevelopable ruled surface will cut the size of the error. Proposed cutting plan for non-developable ruled surface flank milling can control the cutting size of the error volume or to avoid the overcutting. This paper proposed a modify method, Using over-cut error estimation method, the orientation of the tool movement to an appropriate offset to avoid the flank milling, increase the accuracy of the product in the flank milling, the proposed method through the MATLAB program write non-developable ruled surface parameters equation error method, supplemented by data over this paper, precise calculation of the tool end of each tool path coordinates and location of the tool, and analysis of planning and through the instance axis side of the end milling non-developable ruled surface of the tool path information obtained by MATLAB. The results showed that the actual cutting and then through the CAD / CAM software simulation machining, this method can make sure control the cutting error and avoid the cut occurred. This method can be applied to the thin wall of the impeller blades cutting in order to control the blade dimensional accuracy.