The Structure Analysis Of Key Components Of Injection Mould Considering Errors And Thermal Inlfuence

As a kind of basal industrial equipment, the injection mould is wildly used to mold theplastic parts. For the adverse working environment and complex loads, the mould must havesome performances such as high strength, big stiffness, long life, high accuracy etc. Withautomobile industry, household appliance industry and IT industry developing more rapidlyand the process of replacing steel with plastic, replacing wood with plastic speeding up,plastic products market will further expand. There are much more demand and challenges forthe injection mold.Based on angels of errors and temperature filed, the paper makes some research on theimpact relationship between the structure size, size error, temperature field and the injectionmold’s strength and stiffness through structure analysis on injection mold’s key parts, and raisedesign recommendations and improvement programs.Firstly, based on the theory of tolerance analysis, dimension chain and parametric designlanguages, an idea of finite element analysis with the actual size and assembly relationreplacing the ideally designed3D model is introduced. Taking the injection mold’s keyparts-ejector pin and mold cavity splicing structure as the analysis object, the paper researchesanalytic method and numerical method on mold’s Error Modeling and structure analysis, andstudies the influence relation between the size error and equivalent stress.Then based on the error modeling theory the FEA models of the lifter and tool movingdie with size error are established by the means of APDL, and are circularly calculated inANSYS Solver. The influence relation between the structure size, size error, fitting clearancecontrolled by tolerance and mold structure’s equivalent stress and contact stress is studied,which provides theoretical instruction for designing injection mold.Lastly, considering the thermal effects the paper does numerical simulation of injectionmold assembly coupling thermal with structure. The assembly’s temperature field and thermalstress field is calculated, and the thermal effects on the injection mould is analyzed whichestablishes the foundation for the further research of cooling system. The whole paper based on the analysis results and enterprise’s practical experience raisesdesign recommendations and improvement programs, which provides a theoretical basis inorder to improve the performance of injection mould and extend its life.