在铣削圆周等分工件用简单分度分不开时,可采用近似分度法。现有手册和铣工书上都载有近似分度表可供选用。问题是表上的分度方案是否完全合理?近似分度的精度能否进一步提高?要回答这个问题,我们先看看由近似分度所引起的误差大小。设工件的齿数为Z,选用的分度盘孔数为N,则每分过一齿,应转过的孔数为:即应当转过R个孔再加上Z分之Q个孔,当Q不等于零亦即P得不到整数时,就只能采用近似分度。设用一个与Q/Z非常接近的分数K/M来代替它,那 Dividing the workpiece in the milling circle with a simple index can not be separated, the approximate indexing method can be used. Approximate manuals are available on the existing manuals and milling books. The question is whether the indexing scheme on the table is completely reasonable or not, and whether the precision of approximate indexing can be further improved. To answer this question, let us first look at the error caused by the approximate indexing. Set the number of teeth of the workpiece is Z, the number of holes used for the indexing plate is N, the number of holes that should be turned over for each tooth is: that is, R holes should be rotated plus Q holes in Z Q is not equal to zero or P can not get an integer, you can only use approximate indexing. Let’s replace it with a fraction K / M that is very close to Q / Z