Study On The Relationship Of The Structure Characteristics And Shrinkage Of The Injection Molding Gear

With the development of the plastics industry, plastic products have been used widely in the industrial fields and in daily life.. Gear is one of the commonly used mechanical parts; plastic gear with the advantages of light weight, low noise, corrosion resistance etc. gets more and more extensive application. Injection molding is the main processing methods of plastic gear, the shrinkage deformation in the process of forming seriously affects the quality and service life of the gear. The structural characteristics of gear injection inducing contraction deformation analysis are not perfect. This paper mainly aims at the problem of uneven shrinkage in molding shrinkage to study the relationship between the structure characteristics and shrinkage of injection gear.Through the application analysis of plastic gear, the injection molding gear with small module was selected as the research object. Considering the analysis of the structural parameters of the gear, and according to the inherent relationship between the structure parameters, the gear model of different structures was established. Through the analysis of the polymeric materials that are suitable for gear production, POM was selected as gear materials. Through the analysis of gear forming defects, the maximum amount of warpage caused by uneven shrinkage was selected as the target parameter. After meshing all gear models and establishing the cooling system and gating system, set process parameters.Doing the warp analysis of all gear models with Moldflow, using Origin to determine the relationship between structural parameters and target parameters, and then the function type was determined. The mathematical relationship between structure parameters and target parameters of the gear was obtained by using MATLAB to fit data. According to the error comparison between calculation results with formula and simulation data, verified the rationality of the fitting formula. This study offers a basic mathematical model for parametric design of gears and provides some guidance for the study of injection gear. At the same time, it provides a new research method for the injection molding, especially for which has the same structure characteristics.