杯形薄壁梯形内齿轮旋压成形机理研究

杯形薄壁内齿轮的旋压成形是旋压技术在应用领域的又一拓展，与传统筒形件流动旋压不同的是，其成形的目的不是材料的整体减薄，而是材料的局部增厚，因而其变形机理十分复杂。论文采用数值模拟和工艺试验相结合的方式，从成形过程中材料的流动入手，对其变形机理进行了研究。研究结果表明：内齿轮轮齿的旋压成形过程，是“镦挤”复合变形；变形分布呈现出周期性，不均匀性和不对称性等特点；轮齿成形受工件转动方向影响，且易出现成形缺陷。

Spin-Forming Mechanism of Cup-Shaped Thin-Walled Trapezoidal Inner Gear

Spin-forming of cup-shaped thin-walled trapezoidal inner-gear is an expansion of product scope. The aim of material deformation is local thickening rather than global thinning, which is different from the conventional flow-forming. So its deformation mechanism is complex and it is necessary to analyze the deformation characteristics. Numerical simulation and processing experiment were adopted to analyze the material flow status. The results show that: a) inner gear spinning is upset-extrusion forming process; b) deformation distribution is un-uniform, periodical and dissymmetric; c) forming of gear-tooth is influenced by rotation direction of main spindle and forming defects easily occurs in wall-side of gear-tooth.