超薄板微弯曲成形的回弹研究

Research on Springback of Micro-bending Forming for Ultra-thin Sheet

回弹是影响微弯曲成形件精度的重要因素之一。借鉴宏观模具设计理论,设计了V形微弯曲模具,对H62(Y2)薄板的微弯曲成形回弹进行了研究,揭示了弯曲角、摩擦条件和成形速度对回弹的影响规律。结果显示,弯曲角度、摩擦条件、成形速度都是影响回弹的重要因素,其中弯曲角对回弹影响很大;针对热处理后的材料,当弯曲角为60°时,出现负回弹;无润滑时回弹最严重,当采用豆油和聚氟乙烯作为润滑剂时,回弹率降低,采用石墨为润滑剂时回弹值最小;当成形速度从0.05 mm/s增加到0.15 mm/s时,回弹率逐渐增加。

The springback is one of the important factors influencing the precision of micro-bening forming parts. The V-shape micro-bending die was designed with the help of the macro die design theory. Then the springback of the micro-bending for H62 （Y2） thin sheet was investigated. The influence laws of bending angle, friction condition and forming speed on the springback were revealed. The results show that the bending angle, friction condition and forming velocity are important factors of influencing the springback.The bending angle is the most important factor of influencing the springback. When bending angle is 60°, the springback value of materials is negative after the heat treatment. The springback is severe if no lubrication. The springback ratio decreases when using the cooking oil and the polyvinyl fluoride as the lubricant. The springback value is minimal when the lubricant is graphite.The springback ratio increases gradually when the forming speed increases from 0.05 mm/s to 0.15 mm/s.