在锻模加工中,经常会碰到半圆形的模膛(如图1)。过去加工这种模膛的方法是:先粗铣,然后精铣,最后由钳工修整。用以上的方法加工有以下几个缺点:1)需要新制很多圆球形铣刀;2)用圆球形铣刀加工出的模膛,两端是球形的,需要钳工修整,浪费许多劳动力(图2中的实线部分是 In the forging process, often encounter semi-circular mold cavity (Figure 1). In the past to process the mold cavity is: first rough milling, and then fine milling, and finally trimmed by the fitter. The above method has several shortcomings: 1) a lot of spherical ball mills need to be newly made; 2) the bores machined with ball-shaped mills have spherical shapes at both ends and require fitters to trim and waste a lot of labor (Figure 2 The solid part of the line is