注射机导柱断裂成因分析及疲劳寿命预测  

Analyze the reason of fracture and predict fatigue life for guide pillar of injection machine

作　　者：李金国[1,2] 管敏策[1] 汪超[1] 刘红[2] 

机构地区：[1]台州职业技术学院机电工程学院,台州318000 [2]浙江工业大学机械学院,杭州310014

出　　处：《机械设计与制造》2011年第1期213-215,共3页Machinery Design & Manufacture

基　　金：科技部关于科技人员服务企业行动项目(2009GJC20031)

摘　　要：橡胶注射机合模机构中的导柱在承受复杂载荷工况下,使用1.5年半左右发生疲劳断裂。因此采用数值模拟技术对合模机构进行力学性能分析,寻找断裂原因。根据合模机构的结构和载荷的对称性,取模型的四分之一作为几何求解域,以面-面接触方式定义多区域非线性接触关系,采用粘接模型简化螺纹连接,模拟结果表明导柱颈部的应力集中是其断裂的主要成因,且模具的接触面积越小,导柱颈部的应力越大。采用电测法对合模机构正常工作下的应力水平进行实测,实测结果与数值模拟结果相吻合。在此基础上,对合模机构进行了结构改进,分别计算结构改进前后的疲劳寿命,对比发现改进后的导柱寿命明显提高。Under the complex loads,the injector guide pillar（IGP）is fracture after it used 1.5 years.In order to determine the cause of the fracture,the numerical simulation technology is applied to analyze the mechanical properties of the IGP.Because of the symmetry structure and loads,it is easy to obtain 1/4 geometry model as input model of FEA.For modeling contact between mating surface of the clamping mechanism,nonlinear multi-region contact of surface-surface is applied to establish contact model of FEA.The constraint of tie is used for modeling thread joint.Some conclusive results have been drawn from the simulation including the location and maximum stress concentration factor in the IGP,and the smaller area of die contact surface,the bigger value of stress in the neck of IGP.Electronic measurement is used to test the value of stress in IGP,the experimental results agreed well with simulation data.Finally,based on the problem of fracture,the structure of IGP is improved and the fatigue life is calculated,compared with the original,the service life of IGP is evidently enhanced.

关 键 词：注射机导柱 数值模拟 实验研究 寿命预测 

分 类 号：TH12[机械工程—机械设计及理论]