一、问题的提出用于多面体角度控制的方法有多种,通常是比较法和对分法相结合使用。例如:在加工二十四面体时,先加工一组互为平行的面,并籍此以对分法加工出六个面后,再用30°块规加工第九面,以提供进一步对分的基准。对分法不仅能保持测量条件的一致性,而且所测的角宽度为实际误差的2倍,加工中又可将基准存在的误差均匀分布于两底角。这些优点,是其它方法不可比拟的。而比较法会导致工件误差的增大,直接影响工件的加工精度。由于多面体工作面数的不同,常用的有十几种,尽管种类较多,但其面数则多为某一基数(如3、4、5等)的偶数倍数。此类工件在一般情况下,都可在对称的几个面的基础上,用对分法成倍地加以细分。如:三面,可分出六面,再分出十二面、二十四面 First, the problem raised There are many ways for angle control of polygons, usually the combination of comparative and dichotomous methods. For example, when working with tetrahedron, first machining a set of mutually parallel faces and then forming six faces by the dichotomy, then machining the ninth face with a 30 ° gauge to provide further Points benchmark. The dichotomy can not only maintain the consistency of the measurement conditions, but also measure the angular width of the actual error of 2 times the processing and the reference can be the existence of the error evenly distributed in the bottom two corners. These advantages are incomparable with other methods. The comparative law will lead to increased error of the workpiece, a direct impact on the workpiece machining accuracy. Due to the different number of polyhedron face, there are dozens of commonly used, although the type is more, but the number of faces is mostly an even multiple of a certain base (such as 3,4,5, etc.). Under normal circumstances, these types of workpieces can be subdivided by the dichotomy on the basis of several symmetrical surfaces. Such as: three, can be divided into six, and then divided into twelve sides, twenty-four side