一、前言近年来,由于自动化装配和无调整作业的需要,对冲件的精度和通用性要求也提高。在弯曲加工中,材料的回弹是确保精度最困难的因素之一。即使在相同条件下,由于材料厚度和特性的变化,尺寸精度就会恶化。三菱电机公司电计量化中所使用的制动磁铁,要求其中 U 字形轭铁架具有很高的弯曲精度,以缩短电计量仪的调整时间,减少磁化不良及磁钢数量。 I. Introduction In recent years, due to the need of automated assembly and non-adjusting operation, the accuracy and versatility of hedging pieces have also been raised. In bending, material rebound is one of the most difficult factors to ensure accuracy. Even under the same conditions, dimensional accuracy deteriorates due to changes in material thickness and characteristics. Mitsubishi Electric Electric metering used in the brake magnet requires U-shaped yoke which has a high bending accuracy to shorten the adjustment time of the electric meter to reduce the poor magnetization and the number of magnets.