音乐盲盒外壳CAE优化与强脱机构模具设计

CAE⁃Optimization and Mould⁃Design with Forcing⁃Demoulding⁃Mechanism for Music⁃Blind⁃Box⁃Shell

音乐盲盒外壳塑件注塑成型的难点为卡扣公扣4个扣勾收缩变形量的控制及其自动化脱模。基于此,要求公扣4个扣勾的装配扣合量tc及靠边间隙δ3的设计目标值tc+δ3=0.58 mm,通过CAE优化分析得到的模腔单腔扇形侧浇口尺寸为4 mm×0.8 mm;然后,在模具温度为83.64℃、注射时间为1.371 s、熔体温度为256.8℃条件下,塑件的成型质量最优分数为0.8658,对应的4个扣勾成型尺寸中,1号、4号扣勾之间收缩后内径ϕn′m′=32.37 mm,2号、3号扣勾之间收缩后,内径ϕn′m′=32.59 mm,该尺寸能保证成型后塑件的扣接使用功能。模具为1模2腔两板模具。模具中,结合4个扣勾的脱模,设计了一种扣勾2次顶出强制脱模机构,实现了塑件的自动化脱模,该机构中二次推板能实现内层推管的顶出脱模,机构使用了5层同心成型件实现该局部特征的成型与脱模,采用二次推出机构实现了最内层推管的顶出驱动,避免了同类设计中为解决该难题而采用多板模、多次开模驱动造成的模具结构设计较复杂的问题。

The difficulty of injection molding the outer shell of a music⁃blind⁃box lied in the control of the shrinkage deformation of the four buckles of the male buckle and the automation of demoulding.Based on this,a target value of tc+δ3=0.58 mm was designed for the assembly clamping amount tc and edge clearanceδ3 of the four buckless of the male buckle.Firstly,the size of the single cavity fan⁃shaped side gate obtained through CAE optimization analysis was 4 mm×0.8 mm.Secondly,under the conditions of mould temperature 83.64℃,injection time of 1.371 s,and material melt temperature of 256.8℃,the corresponding optimal plastic part forming quality score was 0.8658.Among the corresponding four buckles’hook forming sizes,the inner diameterϕn′m′=32.37 mm after shrinkage between the first and the fourth hook was obtained.And with an inner diameter ofϕn′m′=32.59 mm after shrinkage between the 2nd and 3rd buckles’hook,this size could ensure the functionality of the formed plastic part for fastening.A two⁃plate⁃mould with one mould layout two cavities for plastic part was designed.A forced demoulding mechanism with two ejections of four hooks was designed in the mould to achieve automatic demolding of plastic parts.In the mechanism lied in the fact that the secondary push plate could achieve the ejection and demoulding of the inner push tube,the mechanism used 5 layers of concentric molded parts to achieve the molding and demoulding of this local feature,cleverly using a secondary ejection mechanism to achieve the ejection drive of the innermost push tube,avoiding the complexity of mould structure design caused by multiple plate mould opening driving used in similar designs to solve this problem.