應用田口法於五軸CNC銑削加工製程之最佳化參數設計

Optimization of Five-axis CNC Milling Operations using Taguchi Methods

黃繼輝(Chi-Hui Huang)

指導教授 ： 陳政順

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.2008.00569

摘要

現今產品設計的造型多為複雜曲面，由於五軸加工之特性與優勢，使得應用五軸加工技術取代三軸加工成為業界的主流。本研究的目的在於嘗試找出利用五軸銑削曲面時之最佳參數。本研究之實驗機台為本實驗室之床台傾斜旋轉型態之五軸加工機，加工的成品模型為凹型半球面，其材料為NAK80模具鋼。實驗程序為使用L9(34)直交表、計算訊雜比、繪製折線圖和反應曲面、最佳化實驗因子和使用ANOVA分析表驗證田口法的正確性與各因子的貢獻度；實驗的因子有切削速度、進給率、刀具路徑規劃和表面接觸點，同時每因子都設定為三個水準。本研究的品質特性為望小特性，亦即取得較小的表面粗糙度值為佳。實驗結果顯示利用12,000rpm的切削速度、600mm/min的進給率、五軸同動的路徑規劃與360個接觸點可以達到較佳的表面粗糙度。ANOVA分析表也驗證了與田口法的實驗結果是一致的，同時也以刀具規劃因子貢獻度最大，有60.5%的影響力，其次為主軸轉速，接下來為進給率，影響程度最不明顯的為刀具接觸點。除此之外，也進行真圓度的分析，其品質特性也是望小特性，運用與研究表面粗糙度相同的流程得到的最佳化結果為五軸同動放射狀加工路徑，主軸轉速為10000rpm，進給率為900mm/min，刀具接觸點為360個接觸點。真圓度的ANOVA分析也得到與田口法相同的結果驗證了實驗的正確性，同時也發現以路徑規畫因子對真圓度的影響最大，有高達25%的影響程度，其次為刀具接觸點，只有8%，接下來則是刀具接觸點有2%的貢獻度，至於進給率對於真圓度的影響就更小了。

關鍵字

五軸銑削加工 ； 田口法 ； 製程參數最佳化

並列摘要

Different kinds of complex surfaces of products have become popular in product design in recent years and consequently 5-axis machining techniques become a mainstream in the manufacturing of the die and moulds used in products mentioned above, because of their features and flexibility. This research applies Taguchi method to find out a set of optimal machining parameters in five-axis milling process. The table rotating-tilting type five-axis machine is used to perform the experimental cutting in this study. The geometry of die is modeled as convex half spherical surface, and the material of die is NAK 80 die steel. Experimental procedures consist of using L9(34)orthogonal array, calculating S/N ratio, charting broken-line graph, and response plane, optimizing parameters, an applying ANOVA analysis chart to verify Taguchi experiment results. The four parameters studied are cutting speed, feed rate, tool paths, and contact points, and each of these factors has three levels. The target of this study is the feature of smaller-the-better that is minimization of the surface roughness. The final results of optimal surface roughness experiment shows that the optimal parameters are 12,000rpm cutting speed, 600mm/min feed rate, five-axis tool path, and 360 contact points. The results of ANOVA analysis is correspondent with our research and that can prove Taguchi method is effective. The factors contributing most to the improvement of surface roughness is tool path which accounts for 60.5%,the second is spindle speed. Besides surface roughness, we also conduct research for roundness using the same experiment procedures applied for surface roughness because they have the same quality character. The optimal machining parameters for roundness is 10,000rpm cutting speed, 900mm/min feed rate, five-axis tool path, and 360 contact points. The results of ANOVA analysis is correspondent with our research and that can prove Taguchi method is effective. The factors contributing most to the improvement of surface roughness is tool path which accounts for 25%, the second is tooling contact point.

並列關鍵字

Five-Axis Milling ； Taguchi Method ； Parameter Optimization

參考文獻

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