立式加工中心機之接觸剛性鑑別

A identification of the joint stiffness with the vertical Machining center

黎育翔(YU-HSIANG LI)

指導教授 ： 劉德騏

國立中正大學/工學院/機械工程學系/碩士(2016年)

摘要

本篇建立工具機結構誤差診斷與有限元分析技術，其技術包含(1)鑑別五大鑄件之材料性質，即底座、鞍座、工作台、立柱、頭座及主軸，其實驗方法為固定敲擊位置，移動加速規進行，對每個測量點平均敲擊三次，將該訊號透過快速傅立葉取得頻率響應，並與有限元驗證，(2)為了獲得各部件、構件和零件之間的接合剛性，廠商將配合計畫針對整機採取階段組裝，首先底座安裝地腳於地面上，進行模態實驗測試與分析以鑑別地腳剛性，接著安裝鞍座與底座上用於工具機接合處的機械元件，如Y軸線性滑軌與滑塊接觸面，依序進行整合模態實驗與有限元素分析結果，以鑑別各軸滑塊、螺桿之接觸剛性；接序安裝工作台，重覆上述分析的鑑別與驗證，直至整機安裝完成，(3)由前述步驟完成之機台的動態特性與有限元模型，建立各種加工位置之整機結構的模態頻率表；結果發現透過模態頻率表可得知機台在各個位置的剛性，影響原因有地腳剛性、結構幾何外形等，提供使用者在加工時避開共振頻率，以提高加工精度。

關鍵字

模態實驗驗證有限元素模型 ； 材料性質鑑別 ； 接觸剛性鑑別 ； 地腳剛性鑑別

並列摘要

The paper is to mainly to propose the structural error diagnose and finite element analysis techniques for machine tool, including: (a). Identification of material properties for five casting parts through experimental modal analysis (EMA), i.e. base, saddle, working plate, column, and spindle. (b). In order to acquire joint contact stiffness between each part, the manufactures will coordinate the subproject need to assembly the whole machine tool part by part. First, the base was setup on the ground with foundations. EMA was measured to validate the finite element model (FEM) and identify the foundation stiffness. In the next step, the saddle and the feed systems, e.g. screw and sliders, are setup upon the base to validate the FEM with EMA for acquiring the joint contact stiffness. Then, the working plate was setup to follow the above steps until the whole machine tool was completely setup and analyzed. (c). The validated FEM of the whole machine tool was utilized to establish the modal frequency and shape table under different working position. The result shows that the machine tool stiffness under different working position was acquired and affected by the stiffness of foundations and structural geometry, etc. It can provide the users to avoid the resonance frequency and increase the machining accuracy.

並列關鍵字

Validated finite element model for experimental modal analysis ； Identification of material properties ； Identification of the joint stiffness, ； dentification of the foundaton stiffness

參考文獻

[18] 王栢村、謝宗廷、黃愈憲，“模型驗證工具程式發展與結構模型更新之應用”，第二十屆中華民國振動與噪音工程學術研討會，2012。

[23] 謝宗廷，“組合結構之模擬與模型驗證”，國立屏東科技大學碩士論文，2011。

[1] S. G. Kim, S. H. Jang, Hwang, Y. H. Choi and J. S. Ha, “ Analysis of Dynamic Characteristics and Evaluation of Dynamic Stiffness of a 5-Axis Multi-tasking Machine Tool by using F.E.M and Excit-er Test,” International Conference on Smart Manufacturing Appli-cation, 2008.

[15] 王栢村、曹文昌，“應用有限元素分析與實驗模態分析之結構模型驗證”，中華民國振動與噪音工程學會第十屆學術研討會，第131-138頁，2002。

[16] 王栢村、謝宗廷、陳正陽、周芳俊，“工具機線性滑軌之模型驗證”，兩岸綠色防災科技學術研討會，論文篇號:B06，2011。