注塑机拉杆应力分布的影响因素研究

Affecting Factors of Stress Distribution in Tie-bar of Injection Molding Machines for Plastics

针对注塑机拉杆的早期断裂问题,为使拉杆应力分布合理化,以拉杆与定模板、动模板和调模板等组成的整体有限元分析模型为基础,用优化方法研究拉杆卸载槽的合理位置以及各模板基本厚度的确定,以及拉杆卸载槽的位置和各模板基本厚度对拉杆应力分布的影响。用有限元分析方法对优化结果进行分析,可直观分析与判断拉杆、模板的应力分布状况,用以保证模板结构拓扑优化对其基本参数的要求。有限元分析方法和优化方法的综合运用,可在保证拉杆应力分布合理的前提下,保证模板变形的协调性,以减少其弯曲变形而产生的附加弯矩对拉杆的不利影响。本文的研究方法,可为注塑机拉杆与各模板的设计与改进提供理论依据。

In order to overcome the problem of early failure of the tie bar in the plastics injection molding machine, an integrated finite element analytic model was formulated dealing with the tie bars, fixed platen, movable platen, and rear platen. The reasonable position of slots for releasing stress of tie bars and the proper elementary thickness of platens for a better stress distribution were determined via optimization. The improved stress distribution on the tie bar harmonized the deformation of platens and thus decreased the bending moment on the tie bar.