缝纫机的梭心套壳(图1)是一种深孔薄壁零件。这里主要介绍几种冷挤压梭心套壳的加工工艺。一、采用一次反挤压成形工艺,其冷挤压件图见图2。其加工工序是:落料→滚光→预成形→软化退火→磷化皂化→反挤压成形(见图3)。经过实践,发现凸模严重碎裂,这主要是因为变形量过大。以断面缩减率ε_F 来表示其变形程度。 Sewing machine bobbin case (Figure 1) is a deep-hole thin-walled parts. Here are several cold extrusion bobbin case processing technology. First, the use of an anti-extrusion forming process, the cold extrusion figure shown in Figure 2. The processing steps are: blanking → rolling → pre-forming → softening annealing → phosphating saponification → anti-extrusion (see Figure 3). After practice, it was found that the punch was severely fragmented, mainly because of excessive deformation. Determine the degree of deformation by the reduction of area ε_F.