单件生产中,常常碰到这样一种現象:互相配合的零件,分別按图紙进行加工,其尺寸虽然完全符合零件图的公差要求,但将这些零件装配以后,却达不到設計所需要的配合性能;这时,虽可采用“配作”的办法来保証零件装配后的配合性能,但这样做的結果,零件的实际尺寸却往往超出了图紙尺寸公差。例如,图1所示为冲模中的凸模和固定板的配合情况。冲模工作时,凸模在固定板中是没有相对运动的,但为了保証其准确的中心位置以及修理时装拆的 One-piece production, often encounter such a phenomenon: co-ordination of the parts, respectively, according to the drawings for processing, although the size of the parts in full compliance with the tolerance requirements, but the assembly of these parts, but can not meet the design needs At this time, though the “match” method can be adopted to ensure the fitting performance after assembly, the actual size of the part often exceeds the drawing size tolerance as a result of doing so. For example, Figure 1 shows the mating of the punch in the die and the mounting plate. Die work, the punch in the fixed plate is no relative movement, but in order to ensure its accurate center position and repair fashion disassembly