微銑削之切削力模型修正及切削參數優化研究

Modified Micro-Mill Force Model and Parameter Optimizing for Micro End-Mill

張敏昌(Min-Chang Jang)

指導教授 ： 王世明

中原大學/工學院/機械工程研究所/碩士(2010年)

https://doi.org/10.6840/CYCU.2010.00554

摘要

影響微銑削的切削精度除了機台靜動態精度外，還包括材料在微切削時的性質(最小切屑厚度效應)、微型刀具切削時的振動與撓度變形、刀具磨耗等因素存在。此外主軸在旋轉時的旋轉偏心誤差(run out)也會影響切削量進而切削精度。本研究首先推導建立微銑削力的數學模型，並發展微銑削加工參數優化技術。在考慮刀具振動、撓度變形、主軸偏心及切削效率等條件下，藉由切削參數的選擇，使微銑削製程可得到兼具切削效率及精度的效果。研究中採用瞬時切削投影面積積分法加入主軸偏心與刀具撓度變形考慮，推導出包含加工參數的微切削力數學模型；同時也推導2刃微端銑刀的慣性矩公式，以便分析微銑刀切削時的撓度變形。最後利用實驗分析和有限元素軟體模擬分析，驗證切削力模型的準確性並建立預測模型。研究中也提出以容許刀具變形量反推切削力，進而決定切削參數的最佳切削參數優化法則。

關鍵字

微銑削 ； 切削力 ； 主軸偏心 ； 參數優化

並列摘要

The accuracy of micro machining is influenced by static/dynamic accuracy of machine, materials properties (Minimum chip thickness effect), vibration and deflection of the micro tool, tool wear etc. In addition, because spindle run out will affect the un-deformed chip thickness, it influences the machining accuracy as well. In this study, a cutting force model was derived and used to develop the cutting parameter optimization technology. By taking cutter vibration/deflection and spindle run out into account, the optimal cutting parameters selected by this method can ensure the accuracy and efficiency of a micro machining process. Considering the effect of spindle run out and cutter deflection, calculation of instantaneous projected cutting area was adopted to form the micro milling cutting force model that is function of cutting parameters. In order to analyze the deflection of a micro tool, the moment of inertia of a 2-flute micro end mill was also derived. Finally, the algorithm of selecting optimal cutting parameters was proposed. Experiments were conducted to verify the cutting force model and the algorithm of optimal cutting parameter selection.

並列關鍵字

micro-milling ； cutting force ； spindle run out ； parameter optimization

參考文獻

【1】M.E. Martellotti ”An analysis of the milling process” Transaction of ASME 63(1941) 677-700.

【3】I. Yellowley “Observations on the mean values of the force, torque and specific power in the peripheral milling process” International Journal of Machine Tool Manufactures Design and Research 25(4) (1985) 337-346

【4】L. Zheng, Y.S. Chiou, S.Y. Liang “Three dimensional cutting force analysis in end milling” IJMS 38(3) (1996) 259-269

【5】Z.J. Yuan, M. Zhou, S, Dong “Effrct of diamond tool sharpness on minimum cutting thicknes and cutting surface integrity in ultraprecision machining” J. Mater. Process. Technol. 62 (1996)327-330.

【6】 W.Y. Bao, I. Tansel “Modeling micro end milling operations, Part I: analytical cutting force model” International Journal of Machine Tool and Manufacture 40(2000) 2155-2173