Glass Fiber Reinforced Plastics Automobile Front-end Module Structure Design And Process Optimization

Reducing automobile weight is one of the most effective measures to reduce fuelconsumption and emissions. Light quality, good shock absorption, noise eliminationperformance and great design freedom are the advantages of plastic auto parts, so they arewidely used in the automotive industry. The use of plastic front-end module not onlycan effectively reduce the quality of the vehicle, but also avoid welding error andaccumulative error in the front of the car body and also enhance the quality of the frontface of the car body and design freedom. In addition, applications of plastic front-endmodule can reduce costs and the difficulty of assembly. Therefore, studying on thestructure design of all-plastic front-end module of the car and injection molding processis greatly significance for the development and application of automotive plastic parts.Combining with the principle and molding process of plastic product design, thispaper used CATIA software to establish3D geometric model of all-plastic front-endmodule based on the dimensions of front-end assembly structure of C204car and themain assembly relation. Meanwhile, Based on the general test standard of QC/T15-1992automotive plastic products and the finite element method (FEM), Static analysis andmodal analysis were used in front-end module model, then structure optimization designwere also completed.According to the principle of injection molding process design and materialforming process properties, the front-end module process system was designed. Themanufacturing defects existing in the process of front-end module forming wereanalyzed in this paper. And emphases were put on the influence of the filling time,temperature, cavitation, weld lines and warpage on mold filling flow and warpageanalysis. Then the influence of melt temperature, mold temperature, injection time,holding time on product quality such as warpage were investigated with orthogonal testand extreme difference analysis. The research results are as follows:1) The quality of plastic front-end module for2.6Kg was lighter than the front-endassembly structure of original steel automotive for8.4Kg by69%, which effectivelyreduced the weight of the front-end car body and met the assembly requirements;2) The designed plastic front-end module met the general test performancerequirements of QC/T15-1992automotive plastic products, and the maximum stresswas less than allowable stress under working conditions. The deformation was less than the deformation of test criteria, which could satisfy the use requirement;3) Modal Analysis showed that the natural frequency of the plastic front-endmodule reached30.42Hz, which could satisfy the vibration endurance test;4) Pouring Scheme of4gates and the related parameters were determined throughoptimization design of runner system;5) The optimum values of these parameters were confirmed to be：melt temperatureof235℃, mold temperature of35℃, injection time of3s, dwell time of10s byorthogonal design and range analysis.