一种开阔自由凹曲面五坐标加工多点刀位算法  

Multi-Point Tool Positioning Strategy for Five-Axis Machining of Open Sculptured Concave Surfaces

作　　者：樊文刚[1] 王小椿[1] 姜虹[1] 蔡永林[1] 

机构地区：[1]北京交通大学机械与电子控制工程学院,北京100044

出　　处：《西安交通大学学报》2010年第9期69-73,共5页Journal of Xi'an Jiaotong University

基　　金：国家"十一五"重大专项资助项目(2009ZX04009-011)

摘　　要：为了采用圆环面刀具加工开阔自由凹曲面,提出了一种简单快速的五坐标多点刀位算法.通过构造等距面,圆环面刀具的圆环面与理想曲面的相对关系可以等效为刀具环心圆曲线与等距面的相对关系.在等距面上构造偏置距离等于最大允许残余高度的新等距面,建立在新等距面一点处由法矢量和最小、最大主曲率方向矢量确定的局部坐标系,通过坐标变换得到空间坐标系下刀具环心圆曲线的参数方程.利用改进的求曲线曲面最小距离算法,得到不同刀位下刀具与新等距面的干涉量,当干涉量满足精度要求时停止调整刀轴,可以得到最优刀位.算例显示,新多点刀位算法不仅可以产生大的有效切削宽度,而且比以往的多点刀位算法具有更高的计算效率.For open sculptured concave surface machining by the toroidal cutter,a new simple and fast five-axis multi-point tool positioning strategy was presented.Constructing the offset surface,the relative location relationship between the toroidal surface of toroidal cutter and the design surface got equivalent to the relation between the circular curve of toroidal cutter and the offset surface.Then a new offset surface based on the first offset surface was formed,where the offset distance was equal to the allowed maximum scallop height.As the local coordinate system for the point on the new offset surface was determined by the normal direction,the minimum direction and the maximum direction of curvature,the parametric equation of circular curve in the space coordinate was easily obtained by coordinate transformation.With the improved algorithm for computing the minimum distance between curve and surface,the interference between the circular curve and the new offset surface for each tool axis was calculated,which was finished when the interference satisfied the required precision,thus the best tool position was achieved.An example shows that the new multi-point tool positioning strategy enables to produce enough effective cutting width with higher computing efficiency than the existing multi-point tool positioning strategies.

关 键 词：五坐标 多点加工 刀位 自由凹曲面 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]