本文根据金属在锥形模中的变形特点, 求出了模壁对弯曲毛坯第一个支撑点的位置和毛坯在锥形模中的最大弯曲;确定了锥形模膛的最小长度、模腔锥角与毛坯长度的关系;利用压杆塑性稳定条件,导出了锥腔的临界角;提出了不产生塑性失稳镦锻的综合条件. According to the deformation characteristics of the metal in the conical die, the position of the die wall on the first support point of the curved blank and the maximum bending of the blank in the conical die are obtained. The minimum length of the conical die cavity is determined, The relationship between the taper angle and the blank length, the critical angle of the cone cavity was deduced by using the plastic stabile condition of the compression rod, and the comprehensive condition for not upsetting the plastic instability was proposed.