| With the diversification of demand and the continuous development of technology,the shape and function of automobile lamp technology are becoming more and more refined.The light guide is particularly critical as the brightness enhancement component of the car lamp,which can ensure the uniform light emission and enhance the brightness of the car lamp.It is widely used in automobile fog lamps,daytime running lamps and tail lights,etc..Aiming at the phenomenon that light guide plastic parts are prone to warpage and shrinkage,In this paper,a strip-shaped transparent PC light guide for an automobile front combination lamp with a thickness of about 10 mm and a maximum size of about 150mm×215mm×200mm is the research object.The light guide molding technology is introduced from four aspects of raw materials,injection molding machines,molds and molding methods,and related researches on injection molding at home and abroad in recent years are introduced from multiple points.At the same time,the theoretical basis of CAE technology and related rheological equations are described,and the warping deformation and volume shrinkage mechanism of the light guide are introduced.Carried out numerical simulation and mold design research,introduced the principle of total reflection of the light guide,and designed the stepped surface parting" method according to the structural characteristics of the light guide.Combined with CAD/CAE technology,the single-gate molding program was determined,the numerical simulation results of the molding program were analyzed in detail,and a set of hot runner injection mold was designed based on the molding program.Researched the molding process based on the Optimal Latin Hypercube Design(Opt LHD),determined mold temperature A/?,melt temperature B/?,holding time C/s,holding pressure D/%,cooling time E/s as test variables,and the volume shrinkage rate X/%,sink mark index Y/%and warpage deformation amount Z/mm were determined as the response target.Using the test samples obtained by Opt LHD,combined with the Moldflow analysis to obtain the test data,a response surface model for the three response targets was established.Based on the response surface model,the influence of each test variable on the response target is analyzed.The optimization of process parameters based on multi-objective algorithm is studied,and adaptive simulated annealing algorithm(ASA)and archived micro-genetic algorithm(AMGA)were respectively selected to optimize the target value.Through comparison,it is known that the AMGA algorithm converges by the optimization result,and the Parto solution set is better,the AMGA algorithm optimization value is less than the ASA algorithm optimization value,and the effect is better.The obtained AMGA algorithm optimization process parameter combination is A is 71?,B is 280?,C is 8.1s,D is 91%,E is 24.2s,and The response target after actual simulation is 9.297% for X,6.421% for Y,and 2.752 mm for Z.The optimization results of the two algorithms were verified by simulation,and it was found that the error between the optimized value of the AMGA algorithm and the simulated value was smaller,both less than 3.5%,which confirmed the effectiveness of the optimization of the AMGA algorithm.The production verification was carried out according to the AMGA algorithm optimization parameter combination,and the obtained light guide products were of excellent quality.The actual production plastic parts inspection data and the algorithm optimization data were highly consistent with minimal errors.It is indicated that the method of controlling the volume shrinkage and warping deformation of the photoconductive plastic parts by applying "photoconductive numerical simulation + photoconductive die design + experimental scheme design + establishment of approximate model + multi-objective optimization" has practical application value and reference significance,and the research can improve the molding quality and reduce the production cost. |
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