[问]圆盘凸轮加工在工厂里经常遇到,可是按设计要求的理论夹角(图1中α_3α_4)加工,往往不合格。升高率大时更显著。而实际使用时都要修理,不知原因何在?(北京可明)[答]在加工过程中,不能直接用设计所给的理论夹角,而应通过计算求出阿基米德螺旋线的实际夹角。再根据实际夹角来计算升值、导程、挂轮及磨削时的块 [Q] Disc cam machining is often encountered in the factory, but according to the design requirements of the theoretical angle (α_3α_4 Figure 1) processing, often unqualified. When the rate of increase is more significant. But the actual use must be repaired, I do not know why? (Beijing Ming) [A] in the processing, can not be directly used to design the theoretical angle, but should be calculated by calculating the actual Archimedean spiral Angle. According to the actual angle to calculate the appreciation, lead, hanging wheel and grinding block