汽车尾灯灯罩三色成型方法及模具结构设计

The Three-Color Forming Method and Mould Structure Design of the Lamp Cover of Automobile Back-Lamp

针对塑件三色成型的要求,设计了一种双色结构形式的三色注射成型模具。该模具实现塑件三色成型的方法为:在第一色成型子模具中,利用2条独立的热流道,分别对2个独立色相中间体成型腔同步进行充填,先完成三色塑件中2种颜色中间体的注射成型。然后,在第二色成型子模具中,利用第3条热流道完成第3种色相中间体成型腔的充填,最终获得完整的三色成型塑件。在双射注塑机的基础上,增加一副垂直料筒机构。此方法能够使三色成型模具转变为两色成型模具,有利于模具结构得到简化,降低模具加工制造成本和操作控制难度。在该模具中,2副1级子模具均使用两板结构形式的热流道两板模,使用顶针+顶块的形式完成塑件的完全脱模。在第一色子模具中,使用2条热流道来同步2个中间塑件的设计方法,能够为双色或多色塑件的成型模具设计提供有益借鉴。

According to the requirements of three-color-molding of plastic parts,a three-color-injection mold with two-color structure was designed.The method to realize the three-color-molding of plastic parts is as follows:in the first color molding sub-mold,two independent hot runner were used to simultaneously fill the two independent intermediate molding cavities,first to complete the injection molding of two color intermediates in the three-color-plastic parts;then in the second color molding sub-mold,the third hot runner was used to complete the filling of the third intermediate molding cavity,and finally obtain complete three-color-molding parts.Correspondingly,it is necessary to add a pair of vertical barrel mechanism on the basis of double injection molding machine.With the application of this method,the three-color forming mold was transformed into two-color forming mold,the mold structure was simplified,and the manufacturing cost and operation control difficulty of the mold were reduced.In this mold,two hot runner two-plate-molds with two plate structure were used in the two sub-molds,and the complete demoulding of plastic parts was completed by the form of thimble and block.The design method of using two hot runner to synchronize the two middle plastic parts in the first color sub-mold could provide a useful reference for the mold design of two-color or multi-color plastic parts.