| The combination of induction heating and molding can not only improve the performance of the product,but also significantly increase the productivity of the product,which requires not only high heating efficiency,but also temperature uniformity to meet the production requirements.As the traditional spiral coil is not suitable for integration inside the mold,this paper designs a different shaped induction heating coil from the spiral and explores the feasibility of this coil heating method,with the following main research elements:The five factors of heating distance,channel design,mold material,current and frequency were used as research parameters.The effect of different single factor parameters on the heating efficiency and mold temperature uniformity was investigated using COMSOL Multiphysics finite element software,where the heating distance was selected as 5 mm,7 mm and 9 mm,the channel design was 10 channels and integral channels,the mold material was H11,and the study shows that:(1)the temperature uniformity improves with increasing heating distance.(2)With the 10-channel design,the heating efficiency of the mold is lower than that of the integral channel,but the mold temperature uniformity is better than that of the integral channel.(3)The heating efficiency and temperature uniformity is better than that of P20 when H11 is used as the mold material.(4)The heating efficiency is affected by the coil current,and the temperature uniformity decreases as the current increases.(5)When the frequency is chosen to be 30 KHz,the mold temperature distribution is most uniform.Finally,the extreme difference method and the response surface method were used to study the magnitude of the effect of different factors on the heating characteristics of the mold and the synergistic effect between the two factors.Since heating efficiency and temperature uniformity are two conflicting objective functions,this paper uses a Kriging model combined with a genetic algorithm to optimize the multi-objective problem,using current and frequency as optimization factors and fixing the remaining three parameters at the same level.A linear weighting method is used to establish a comprehensive quality model,transforming the multi-objective optimization problem into a single-objective optimization problem,and using the Latin hypercube sampling method to extract sample values.The optimization results were when the coil current was taken as 1335.6A and the frequency was taken as 43.4 KHz,the mold heating efficiency was 46 s and the temperature extremes were 3.15°C.All data are better than the optimum value of Latin hypercube sampling.Taguchi method with the introduction of signal-to-noise ratio and ANOVA were used to study the influence of the experimental parameters of molding on the mechanical properties of the products.The selected molding parameters were preheating temperature,molding pressure and mold temperature,and the mechanical properties tests included 0° tensile properties,bending properties and short beam shear properties.The DOE method was used to establish the L9 orthogonal experimental table,and the extreme difference method was used to study the influence of different factors on the mechanical properties.For the bending performance,the different factors were ranked as follows: molding pressure,preheating temperature and mold temperature,with the best bending strength when the combination of parameters was A1B1C1 and the best bending modulus when the combination of parameters was A3B1C3;for the shear performance of short beams,the factors were consistent with the bending performance,with the best shear strength of short beams when the combination of parameters was A3B1C2.Finally,ANOVA was used to investigate the importance of different parameters on the mechanical properties. |
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