Abstract: Uneven thickness distribution was the main reason for affecting product performance and forming quality when single-point incremental forming the thin-walled parts with complex shapes. Hydraulic supporting was introduced into the single-point incremental forming process, and a hydraulically supported single-point incremental forming process was proposed, uniform distribution of thickness was promoted by adding flexible support to the overhanging sheets. Conical parts with different wall angles were formed by single-point incremental forming of Al1060 sheets under the auxiliary supports of hydrostatic and variable pressure, the effects of hydrostatic parameters and variable pressure schemes on the thickness distribution and the critical angle of thickness uniformity were quantitatively analyzed through numerical simulations and experimental studies. The results show that the favorable hydrostatic pressure range is as 0~0.18 MPa for the critical angles of uniform thickness distribution, and the most favorable hydrostatic pressure value is as 0.17 MPa. Compared with unsupported single-point incremental forming, the hydraulically-supported single-point incremental forming process may increase the critical angle of thickness uniformity by 7°, which effectively improves the uniformity of thickness distribution and forming performance of the sheets.

Key words: incremental forming, hydraulic support, critical angle, thickness distribution

摘要： 单点渐进成形复杂形状的薄壁制件时，不均匀厚度分布是影响产品性能和成形质量的主要原因。将液压支撑引入单点渐进成形过程中，提出一种液压支撑单点渐进成形工艺，该工艺通过对悬空板材增加柔性支撑来促进厚度的均匀分布。在静压和变压的辅助支撑下，采用Al1060板材单点渐进成形不同壁角的圆锥台制件，通过数值模拟和实验研究定量分析静压参数与变压方案对厚度分布及厚度均匀临界角的影响规律。结果表明，对厚度均匀分布临界角的有利静压压力范围为0～0.18 MPa，最有利的静压压力值为0.17 MPa。与无支撑单点渐进成形相比，液压支撑单点渐进成形工艺可以使厚度均匀临界角增大7°，有效提升板材的厚度分布均匀性和成形性能。

关键词: 渐进成形, 液压支撑, 临界角, 壁厚分布