一种五轴NC加工刀具方位的自动化判定方法

One Kind of 5-axis NC Machining Tool Automated Method for Determining the Orientation

文章是针对具有倒钩几何形状的凹穴进行五轴NC加工时所产生的干涉碰撞问题,利用Openregion及向量的概念,提出一简单的方法来调整刀具的方位。此方法首先将要加工的凹穴曲面转换为离散的点数据后,然后将工件作2D切层,并进行切层之间的比较,以取得每一倒钩区开始的高度值(即Open-region发生的位置),最后作NC加工刀具路径的规划。无干涉的刀轴轴向是采用初始轴向及干涉检测两阶段式的方式来决定,初始刀轴轴向是利用在Open-region轮廓所得的点数据与CC point间所产生的向量,根据向量间的角度判断所得。完成了初始刀轴轴向的选取后,接着作干涉检测,若有干涉的现象,则做刀轴轴向修正的动作,如此反复直到没有干涉为止。

This study deals with the problem of collision generated from 5-axis NC machining on cavity with geometry of undercut by proposing a methodology to adjust the attitude of tool,using the concepts of openregion and vector filed. The first step is converting the to-be-machined cavity surface into discrete data points. Secondly,slice the surface into 2D layers and compare the contours of slices to obtain the height of each undercut area,i. e. the position where open-region shapes its form. Finally,start planning cutter path of NC machining. Collision-free tool orientation is determined by two stages： initial orientation and collision inspection. An initial orientation of cutting tool is obtained by judging the angle of vectors decided by data points of contour of open-region and CC points. If any occurrence of collision takes place,the initial orientation is adjusted till all obstacles generated from collision cease to happen.