The unit pressure in backward extruding hollow billet has been calculated by the slip line method and the upper bound method.
本文对空心件反挤的单位挤压力，采用滑移线法和上限法进行了计算。
2
As being one of the main middle link of plastic extruding machine and indispensable device of the molding unit, cooling system plays an important role in production equipment and production line.