基于主辅旋轮的曲母线件无芯模旋压成形

无芯模旋压由于不受芯模限制,适合复杂曲母线工件的柔性旋压成形,但仍需一定的辅助支撑,以克服成形形状精度较差的问题。针对主辅旋轮的曲母线件无芯模旋压,运用仿真与实验相结合的方法分析其在有无端部辅助支撑、有无辅助旋轮支撑时的旋压效果,分别对仿真结果的应力、应变、轮廓形状和壁厚分布情况进行了探讨。结果表明,端部辅助支撑有助于提高整体弯折变形效果,辅助旋轮支撑有助于板料局部成形,复合辅助支撑则综合了两者的成形特性,可以得到满足成形质量的工件。另外,通过变进给和首道次预成形直线形状的两道次旋压成形方法,对成形质量进行改善,结果表明两种方法相结合可以明显提高最大减薄率,改善壁厚均匀度。

Spinning of curvilinear generatrix parts without mandrel based on main and auxiliary rollers

Without the limit of mandrel, the spinning without mandrel is suitable to form complex curvilinear generatrix parts. However, it still needs some auxiliary supports to overcome the poor precision of forming shape. For the spinning of curvilinear generatrix parts with-out mandrel based on main and auxiliary rollers, the spinning effects with or without an end auxiliary support or an auxiliary roller support were analyzed by combining the simulation with experiment method, and the stress, strain, profile shape and wall thickness distribution in the simulation results were discussed respectively. The research results show that the end auxiliary support helps to improve the effect of overall bending deformation, and the auxiliary roller support helps to form sheet metal locally. However, the composite auxiliary support can obtain workpiece that satisfies the forming quality requirement by combining their forming characteristics. In addition, the forming quality is improved by taking variable feeding and two-pass spinning with preformed linear shape at the first pass. Thus, the maximum re-duction rate and wall thickness uniformity can be obviously improved by combining the above two methods.