基于摩擦模型的挤压铸造机压射机构动态配合

Dynamic Fit of Injection Mechanisms for Squeeze Casting Machines Based onFriction Model

配合间隙是影响压射机构服役和工艺控制的核心要素,为研究压射机构配合间隙,提出一种压射机构的摩擦模型,并基于MSC.MARC软件二次开发将摩擦模型与数值模拟整合,整合摩擦的数值模拟结果与不考虑摩擦的普通数值模拟结果和压射实验结果的对比验证了整合摩擦模型数值模拟的有效性和准确性。对2500 kN压铸机压射机构进行多循环压射工艺模拟,研究了工作中配合间隙的变化规律,压射、冲头回程阶段的配合间隙变化剧烈,凝固成形阶段的配合间隙变化平缓,变化剧烈的主要原因是压室的轴向温度分布不均匀。

Fit clearance was a key factor affecting service and process control of injection mechanisms,in order to study the fit clearance of injection mechanisms,a friction model of the injection mechanisms was proposed.Friction model and numerical simulation were integrated based on secondary development of MSC.MARC software.The results of numerical simulation integrated with friction were compared with those of ordinary numerical simulation without considering friction and the injection experiments to verify effectiveness and accuracy of numerical simulation integrated with friction.Multi-cycle injection processes for the injection mechanisms of 2500 kN squeezing casting machine were simulated,and the changing rules of the fit clearance were studied.In stages of injection and punch return,changes of the fit clearance are severe.In solidification stage,changes of the fit clearance are gentle.Main reason for drastic changes of the fit clearance is the uneven axial temperature distribution in shot-sleeve.