摘要
通过对正投影图中投影轴分离的研究得出结论：分离投影轴角平分线的平行直线即是转向轴。利用转向轴作图可以简化作图过程，并省去度量问题。
Through the separative study of projection shaft in the orthographic projection,it is concluded that the parallel straight line of angular bisector of separative projection shaft is the steering shaft.In addition,the streering shaft used in making drawings can simplify the process of making drawings and omit the measuring problem.
关键词
正投影
投影轴
角平分线
转向轴
orthographic projection
projection shaft
angular bisector
streering shaft
