不同刀具路徑規劃銑削性能之分析與比較

Milling Performance Analysis and Comparison for Different Tool Path Planning Strategies

廖文成(Wen-Cheng Liao)

指導教授 ： 林盛勇

國立虎尾科技大學/工程學院/機械與機電工程研究所/碩士(2009年)

https://doi.org/10.6827/NFU.2009.00068

摘要

高速切削加工技術是目前工具機產業重要的發展趨勢，是一種搭配高速進給和高切削速度進行加工。當切削條件與刀具路徑規劃搭配得宜，除了切削力較低、切削溫度增加較緩慢外，可進一步提升材料移除率，發揮工具機本身的最佳效能，並有增加生產效率及降低加工成本與時間等優點。
本文主要研究不同刀具路徑下切削性能之比較分析。使用三種刀具路徑規劃策略：偏置(morphing)路徑、擺線(trochoid)路徑、平滑相切連續(tangent-continuous)路徑，進行直線-圓弧側銑刀具路徑規劃做切削性能之比較分析。上述三種路徑分別選用MasterCAM、PowerMILL、SurfCAM三種軟體來規劃銑削刀具路徑與不同切削條件組合，藉由切削路徑圓弧半徑的改變、銑深、進給率等大小不同的組合，以鎢鋼刀側銑6061-T6鋁合金與S50C中碳鋼，皆以乾切削方式進行實驗。側銑過程中以加速度規監測圓弧轉彎處由於切削過載衍生顫振的情形，以動力計量測切削力的變化，並量測工件表面粗糙度等。實驗結果顯示，使用平滑相切連續(tangent-continuous)路徑衍生的顫振行為較小、較穩定的切削力及表面粗糙度較為優良；而偏置(morphing)路徑則會產生較高的顫振、切削力變化幅度較大且表面粗糙度最差。藉由本文所進行的研究，可找出較好的免顫振與穩定切削力的切削性能，發揮機器的真正效能。對從事實務高速切削加工的業者，可有提升切削效率、減少切削加工成本、延長刀具使用壽命、發揮工具機整體效能等成效。

關鍵字

刀具路徑規劃 ； 側銑 ； 顫振 ； 切削力

並列摘要

High speed cutting technique, which is a manufacturing way with high feed-rate and cutting speed, is also an important trend in machine tool industry recently. When cutting conditions match with tool path planning well, material removal rate could further be increased, except for low cutting force and slowly rise of cutting temperature. Therefore, the best efficiency of machine tools could be elaborated and manufacturing cost and time could be lowered.
This study aims to make comparative analysis of cutting performance under different tool paths and three tool path planning strategies, morphing, trochoid, and tangent-continuous, are used to proceed straight-circular side-milling tool path planning. We choose MasterCAM, PowerMILL, and SurfCAM to arrange milling tool path with different cutting conditions. Through changes of circular radius, milling depth, and feed rate, tungsten carbide was used to side-milling of 6061-T6 aluminum alloy and of S50C medium carbon steel. Then, we used the accelerometer to monitor chatter from overload of cutting, and the dynamometer and the surface roughness tester to measure changes of cutting force and surface roughness of the machined surface. The result shows tangent-continuous makes less chatter, stable cutting force, and little surface roughness. However, morphing makes more chatter, cutting force changes, and more surface roughness. This study could help to figure out little chattering and stable cutting force of machines. For manufacturers, it could help promote cutting efficiency, save cutting cost, lengthen the period of tool use and elaborate full functions of machines.

並列關鍵字

tool path planning ； side-milling ； chatter ； cutting force

參考文獻

[1] M. E. Martellotti, “An Analysis of the Milling Process,” Transaction of ASME, 1941, Vol. 63, pp. 677-700.

[2] M. E. Martellotti, “An Analysis of the Milling Process, Part 2: Down Milling,” Transaction of ASME, 1945, Vol. 67, pp. 233-251.

[3] L. Zheng, Y. S. Chiou and S. Y. Liang, “Three Dimensional Cutting Force Analysis in End Milling,” International Journal of Mechanical Sciences, 1996, Vol. 38, No. 3, pp. 259-269.

[4] Chih-Ching Lo, ”A new approach to CNC tool path generation,” Computer-Aided Design, 1998, Vol. 30,pp. 649-655

[5] H.S. Choy, K.W. Chan, “A corner-looping based tool path for pocket milling,” Computer-Aided Design 2003, Vol. 35, pp. 155-166