中文摘要：

提出了一种锥形螺母冷镦挤成形新工艺,运用三维有限元分析软件Deform-3D,模拟了锥形螺母的冷镦挤成形过程,获得了管状坯料在凹模型腔中的流动速度场和温度场分布。结果表明：管状坯料经塑性变形可以完全充满整个模腔,螺纹部位成形饱满,并且没有出现较大的余料飞边和断料缺口;整个挤压过程也未出现大面积的温度不均匀和烧损现象,采用管状坯料冷镦挤成形锥形螺母的工艺是可行的。由此,设计出一套锥形螺母的冷镦挤成形模具,最后通过试验进行了验证。

英文摘要：

A new cold beading extrusion process for forming a conical nut was presented, and the forming process was simulated by three- dimensional finite element software Deform-3D. The distributions of the flow velocity field and the temperature field of the tubular billets in the process of filling the die cavity were obtained, respectively. The results show that the die cavity can be fully filled by the plastic de- formation process of tubular billets. The threads of the forming conical nut are completely full and without larger flashes and broken materi- al gaps. The phenomena of a large area of uneven temperature and hot damage do not occur during the whole extrusion process, which in- dicates that cold heading extrusion process for producing a conical nut by tubular billet is feasible. Finally, a set of die structure for cold heading extrusion of the conical nut was designed and the result was validated by the test.