高直臂小间距等厚板材零件步进式冲锻工艺

Stepping Press Forging Process for Uniform Thickness Parts of Sheet Metal with High Straight Arm and Small Spacing

针对高直臂小间距、不能展平的等厚板材零件,提出了步进式冲锻成形工艺。该工艺先通过冲压成形零件的大间距两直臂,然后通过若干次弯曲工步来缩小两直臂间距直至达到目标值。每次弯曲成形后对工件弯曲变形部位需进行冷锻平整,选择合理的工步数是保证冷锻过程中不出现材料重叠、起皱或破裂等现象的关键。建立了流线型弯曲的数学模型,通过该模型得到每个弯曲工步极限图。采用数值模拟结合试验的方法获得了无工艺缺陷的产品,产品性能优良,生产效率高。该步进式冲锻工艺为成形高直臂小间距等厚金属板材零件提供了新途径。

Stepping press forging（SPF）process was proposed to form parts with high straight arms and small spacing,which could not be formed by normal stamping because the interferes would happen when the straight arms were expanded before stamping.Parts with large space straight arms were formed by stamping initially and then by using several bending steps to narrow the distance between the two straight arms to the target value.Cold forging should be used after every bending step to flat the bending area and it was important to select the reasonable stepping coefficients to avoid the overlap,wrinkling and cracking during cold forging.Bending limit diagrams for every bending step were obtained based on the mathematical model of streamline bending.Numerical simulations together with experiments were used to determine the stepping coefficients with no process defects.The SPF process is a new way to form such parts which have excellent performance and high productivity.