环盖模具设计

根据环盖零件成形系数比第一次成形极限略大,并要求高精度孔的工艺性,提出了2次成形、成形和冲孔分开的工艺方案。模具结构可变换工位,以凸模为中心,旋转凹模,使凸、凹模在不同工作位置,完成不同的冲压工序。详细阐述了如何确定首次成形、冲孔时机的选取以及冲孔孔径的细微变化,使略大一次成形极限能在2个工位同一套模具下完成。简化了薄壁件的成形工艺,且环盖零件无起皱、无拉裂,孔径尺寸稳定。

Design of die for ring cover part

Because the drawing coefficient of ring cover was slightly bigger than the primary drawing limit and because of the high precision reqirement of hole,the twice drawing,and drawing-piercing separated process was put forward.The die could realize shift of working positions through rotation of concave die with the punch at the center.Therefore,the concave die and punch could complete different stamping steps at different working positions.The determination of first drawing degree,selection of piercing timing,and the small change of hole diameter were all discussed elaborately.The part could be formed at two working positions in the same die with forming degree slightly bigger than primary drawing limit.The die could simplify the forming process of thin-wall parts.The produced ring cover parts were free from wrinkling and drawing breakage,and the hole size was stable.