Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/1958
標題: 精密車床主軸頭之最佳化設計
Optimum Design of Headstocks of Precision Lathes
作者: 魏維俊
Wei, Wei-jiunn
關鍵字: optimization;最佳化;headstock;genetic algorithm;主軸頭;遺傳演算法
出版社: 機械工程學系
摘要: 
本文針對三種不同外型的主軸頭進行結構最佳化設計,使工件在切削
點的位移量盡量減小。每種外型分為切削力單獨作用與熱效應和切削力同
時作用兩種情況來討論。熱的來源是出自軸承的運轉摩擦,發熱量的大小
由軸承廠商手冊所提供的公式計算。設計變數包括主軸頭的外型及尺寸,
軸承的剛性及位置,散熱片的位置及大小等等,這些變數包含整數變數及
連續變數,由於遺傳演算法具有全域搜索的能力,而且能夠同時處理連續
變數和整數變數的問題,所以被選來當作本文最佳化的方法。本文使用的
有限元素模型利用MSC/PATRAN來建構,有限元素分析則交由MSC/NASTRAN
處理。文中先針對具有相同外型但是不同受力條件的例子個別討論其結果
的合理性,然後再將這兩個例子做比對,討論其差異性,最後再將三種不
同外型的主軸頭做一比較,挑選出最好的設計。

This thesis deals with optimum design of headstocks with three
different shapes. The design purpose is to minimize the
deflection of workpieces at cutting point. Each kind of
headstock is subjected to two load case. The first load case
includes the cutting force and the second load case combines the
cutting force and the thermal effects. Heat generation is due to
friction which is resulted from bearing revolution. The quantity
of heat generated is calculated by the formula given by bearing
manufactures. Design variables are the shape of headstock, the
size of headstock, the stiffnesses of bearings, locations of
bearings,locations of fins,and the size of fins. These variables
include integer and continuous varilables. Because genetic
algorithm has the ability of global search and dealing with
mixed-variable problems, it is chosen to be the solver. The
finite element model used in this thesis is created by MSC/PATRN
and alayzed by MSC/NASTRAN. Each example which represents one
specific shape is solved twice by the two load cases mentioned
previsously. The validity and difference of the results are
checked and discussed. The optiimun results of the three
different-shape headstocks are compared and the best one is
determined.
URI: http://hdl.handle.net/11455/1958
Appears in Collections:機械工程學系所

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