多台阶空心件的精密成形及有限元模拟

Exact forming technique and FEM on hollow steps shaped part

挤压后的零件不易脱模是多台阶空心零件在挤压成形工艺中的难点。本文介绍了采用分合模机构的挤压工艺,即合模时挤压工件,分模时再顶出。在分析多台阶空心件挤压工艺基础上,运用有限元软件DEFORM对圆台和圆柱两种合适形状毛坯的挤压全过程进行了模拟,分40,55,278,500这4个特征时间步进行分析,得出了金属的流动规律并找到圆柱形是最优的毛坯形状,另外还得到了各个挤压工步的载荷-行程曲线以及侧向胀模力曲线,以便对模具及各种成形参数进行优化。最后按照模拟的工艺参数进行了实验,得出了符合要求的工件。

The forming of hollow steps shaped part by the extrusion forming process is a difficult problem. The law of metal flow can not be clearly understood, and the formed part also can not be easily taken out. A new method which adopts clamping device was introduced. The part was formed when device folds, while taken out when device unfolds. Based on the analysis of hollow steps part extrusion, the entire process simulation of tow kinds stock extrusions were carried out using finite element software DEFORM, in 4 time steps of 40, 55, 278, 500. The law of metal flow was obtained, and found out the column was the best shape for stock. Moreover, the load-stroke curve for all steps and Xload curve were achieved in order to optimize the mold forming parameters. Finally the experiment was done according to the parameters of simulation and qualified part was obtained.