大型无缝铝管材固定针挤压工艺研究

R&D on fixed-mandrel extrusion process of large-size seamless aluminium tube

介绍了几种无缝铝管材挤压工艺,采用理论分析、数值模拟与实验研究相结合的方法,对大型无缝铝管材固定针挤压工艺进行了研究。分析了固定针挤压时穿孔针的受力情况,建立了穿孔针受力的力学计算公式,得出了穿孔油缸系统压力变化公式。采用有限元数值模拟的方法,对无缝铝管材固定针挤压工艺进行了数值模拟,揭示了无缝铝管材挤压过程中穿孔针上拉力与行程曲线的变化规律,据此,提出了实现无缝铝管材固定针挤压工艺的技术路线。研究结果在55 MN油压双动短行程铝挤压机上进行了实验验证。

The different methods of seamless aluminium tube extrusion process were introduced. The fixed- mandrel extrusion process used for large-size seamless aluminiun tube was researched by theoretical analyses, numerical simulation and experimental. The mechanics statue of mandrel in fixed-mandrel process was ana- lyzed. The mechanics calculation equation of fixed-mandrel were set up and the pressure equations of rod cavity of mandrel cylinder were gained. Based on the established FE model, the simulation and analysis has been carried out for the extrusion processes of a large size aluminium seamless tube in fixed-mandrel extrusion. The variation curve of pulling force on mandrel vs. ram displacement of fixed-mandrel for large-size seamless tube extrusion has been obtained. A technical route used for realizing fixed-mandrel process for large size seamless tube has also been put forward. The experiment research has been carried out on the 55 MN aluminun extrusion press with oil-driven double action.