大型截面7A09铝型材拉弯成形工艺研究

Research on stretch bending process of 7A09 aluminum profile with large cross-sectional area

大型复杂截面的型材框在新型运载型号中有着广泛的应用。针对大型横截面积、弯曲直径为Φ5 m的型材框零件进行拉弯成形工艺研究。通过分析润滑方式、预拉力、补拉量等参数对零件回弹的影响,设计拉弯工艺参数：预拉力为450 k N,预拉包角为72°,补拉力为500 k N,补拉包角为82°,补拉量为50 mm。试验表明,采用以上工艺参数得到零件端头回弹量为2.5~3 mm,验证了工艺参数的可行性。通过试验,得到了大型截面、大弯曲直径零件的成形工艺方法,且产品满足使用要求。

Aluminum extrusion with large or complex cross-sectional area is widely used in new aerospace launch vehicle. The process of stretch bending for large cross-sectional area with a bending diameter of 5 m was discussed. According to the analysis on influences of lu- brication, pre-stretching force and post-stretching on springback, a set of optimum technologic parameters was established, namely 450 kN pre-stretching force, 72° pre-stretching angle, 500 kN post-stretching force, 82° post-stretching angle and 50 mm post-stretching value. The experiments show that the springback of the part end is 2. 5 - 3 mm, so the technologic parameters can be adopted. The aluminum ex- trusion with large cross-sectional area and bending diameter is obtained and satisfies the requirements of the products.