高速切削用端銑刀設計與研磨對切削性能的影響分析

Analysis of The Design and Grinding Influence on Cutting Performances of End-mills Utilized for High-Speed Machining

陳麒翔(Chi-Hsiang Chen)

指導教授 ： 李炳寅

共同指導教授 ： 王永成(Yung-Cheng Wang)

國立虎尾科技大學/工程學院/機械與機電工程研究所/博士(2013年)

摘要

綠色切削的發展與應用主要取決於工具機的創新研究、刀具開發的提升及切削技術的精進，其中刀具開發與切削技術的發展具主要暨關鍵之影響。然而，在刀具研磨中，常因為研磨製程的控制參數選用與砂輪磨耗干擾，使得刀具成品與原先設計有所差異，進而影響到銑削加工的刀具壽命與工件表面粗糙度。
此外，在刀具研磨精度、刀具幾何角度、刀具刃口形狀以及切削條件對於銑削性能的影響分析研究，則鮮少被深入研究抑或進行完整之探討。因此，針對此一主題本研究由四個面向切入探討:第一項為刀具幾何角度的解析；第二項探討刀具研磨精度；第三項為分析影響切削性能的參數；第四項聚焦於刃口微幾何的解析。最後，針對四大主題的研究成果，提出端銑刀設計、研磨以及檢驗的關鍵技術。
實驗結果顯示，本研究將端銑刀複雜的三維刀具幾何簡化成二維正交切削進行有限元素模擬分析，其結果可做為刀具幾何設計的依據。在粗加工方面，切削參數為主要考慮因素，尤其是切削速度。精加工方面，除了切削參數的選用，端銑刀具離隙角的設計與研磨為不可忽略的關鍵因素。最佳製程參數設計上，可有效增加刀具壽命、金屬移除體積以及改善工件表面粗糙度。徑向刃口倒角的端銑刀在銑削初期的刀腹磨耗較鋒利刃口的端銑刀大，隨切削時間的累積其刀腹磨耗會逐漸小於鋒利刃口的端銑刀，在較小的徑向切深、軸向切深、每刃進給以及切削速度之下，徑向刃口倒角效益越顯著。本研究的解析方式以及端銑刀具設計與研磨的技術，可協助提升我國在刀具設計的實力以及增加綠色切削效益，對國內刀具磨床製造及刀具加工業者，皆具有帶動技術升級之正面影響，並可望藉以達到強化自主性技術及增進競爭力之優勢。

關鍵字

高速切削 ； 刀具研磨 ； 端銑刀 ； 刃口微幾何 ； 切削性能

並列摘要

The development and application of green cutting is essentially dependent on the innovation of machine tools, enhancements in tool development and more sophisticated cutting technologies. The development of tools and cutting technology has a particularly relevant influence. However, the dimension or geometry of end-mill may vary in accuracy due to incomplete parameter design of control factors or the interference of diamond wheel wear factors that might occur in the tool grinding process. That will affect the tool life and the surface roughness of workpiece in the high-speed machining.
However, few investigations on tool grinding precision are thoroughly involved in the influence analysis of tool geometric and cutting conditions on multiple quality characteristics for milling performance. This proposed study consists of four sections. In first section, the analysis model of tool geometry is investigated. The second one is the analysis model of tool grinding precision. Then analysis model of parameters affecting cutting performance is determined. The final one focuses on the analysis model of cutting edge of micro- geometry. Eventually, according to the results from the four sections, the key technologies of design, grinding and inspection for end mill can be proposed.
The experimental results demonstrate that the finite element analysis model of a macro-milling developed in this study can provide a robust aid tool in end-mill geometric designs for manufacturers or users. For rough machining, tool life and metal removal volume are the primary evaluation indicators and cutting parameters should be primarily considered, particularly cutting speed. Finish machining, workpiece surface roughness are the essential evaluation indicators. Besides the selection of cutting parameters, the design and grinding of endmill are critical factors, especially the design and grinding of relief angles. Verification experiments reveal that the proposed optimization design approach of processing parameters is high potential for improving tool life, metal removal volumes and surface roughness of workpiece under the high-speed cutting. In the initial milling stage, the end-mills with radial cutting edge chamfers yield more significant tool wear in comparison with that of standard end-mills. However, as the accumulated cutting time increasing, the tool wear of the end-mills with chamfers become insignificant in comparison with that of the standard end-mills. Furthermore, at smaller radial and axial cutting depths, the feed per tooth and cutting speed have more significant influences on endmills with radial cutting edge chamfers. That will be beneficial to improve the design, grinding and usage patterns of end-mill. The end-mill can be promoted to the level with the features of the high-performance and green cutting. There would be also positive contribution in technology upgradation for the tool grinder or cutter manufactures in Taiwan. It’s profitable for them to intensify the localization of technologies and enhance the competition.

並列關鍵字

High-speed machining ； Tool grinding ； End-mill ； Cutting edge preparation ； Cutting performance

參考文獻

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