大 型机械制造加工经常会遇到在大直径或超大直径的已加工好的环形工件上划同心圆 ,然后还要划等分孔的工序。大型或超大型环形工件孔的直径 ,有的数米乃至十几米 ,不仅圆心难找 ,而且也没有大型的划规。本文介绍一种美国划大型或超大型环形工件圆周等分孔的简易工具 ,结构简单 Large-scale machinery manufacturing and processing often encounter large diameter or large diameter of the processed ring workpiece on the concentric circle, and then also divide the hole equal to the process. The diameter of large or very large circular workpiece holes, some meters and even a dozen meters, is not only hard to find, and there is no large-scale planning. This article presents a simple tool for dividing the circumference of a large or very large circular workpiece in the United States. The structure is simple