Fatigue Reliability Analysis And Optimization Design Of The Mouse Upper Cover Mold Cavity

Injection molds are important process equipment in industrial production,used to mold various products with certain shapes and sizes.The cavity is one of the main components of the injection mold,which is the molding part of the outer surface of the molded part.The injection mold is a single-piece production,with the characteristics of short lead time,can not be in a short period of time trial products and engineering tests to obtain the specific use of the mold.The cavity of the injection mold is susceptible to overload,cyclic pressure,and continuous heat during operation,which can produce stress concentration leading to premature fatigue failure,and the reliability of cavity operation directly affects the molding quality and economic efficiency of the injection molded parts.Aiming to reduce the number of experiments and save cost,and shorten the development cycle of injection mold,this paper applies the finite element analysis method,fatigue strength analysis method,reliability design theory method and optimization design method to the design research of injection mold cavity.This paper takes injection mold cavity as the research object,and the main research work is as follows:(1)Combining the appearance of the injection molded parts and the requirements of the parameters of the cavity,the three-dimensional model of the mold cavity and the whole injection mold was established;the finite element analysis software was applied to the three-dimensional model for model pre-processing and finite element static analysis to determine the location of its maximum deformation and maximum equivalent force,and the relationship curves of its working pressure and equivalent force were obtained.(2)Based on fatigue strength theory,stress fatigue life of injection mold cavity was analyzed by S-N curve method of nominal stress method,and its fatigue life under different stress conditions was obtained;Using the stress-strength interference model in the mechanical reliability design theory,the reliability of the injection mold cavity under a given life was calculated.The results showed that the injection mold cavity work reliably.(3)The response surface model of the injection mold was solved by genetic algorithm,and a set of better design parameters was selected.Under the premise of ensuring fatigue life and reliability,the mass of the injection mold was reduced by13.86%,and the lightweight design was completed.