自动替换镶件的双色注塑模具设计

Design of bi-color injection mold with automatic replacement of inserts

在双色注塑成型过程中,第一射成型的基体塑件滞留于子动模侧,并随子动模移动至第二射子定模处合模后完成第二射包胶成型。为解决在基体塑件背面(与动模型腔接触的面)进行第二射包胶问题,必须更换子动模相应部位的镶件;为此,通过控制模具开合模动作顺序,利用固定在第一射子定模侧的弯销带动动模滑块及镶件一起移动,实现第一射与第二射不同镶件之间的替换动作,再利用限位块、回位弹簧控制镶件伸出及回位。为防止开模时基体塑件粘附子定模型腔,在第一射的子定模侧设计了以氮气弹簧为主动力的顶出基体塑件机构。为保证自动替换镶件、顶出等机构安全、准确可靠地运行,设计了相应的保障机构。

In the bi-color injection molding process,the first shot of the base plastic part remains on the movable mold side and moves with the movable mold to the stationary mold side of the second shot for a mold closing to complete the second shot of encapsulation molding.To address the issue of encapsulation molding on the back of the base plastic part with a side on the movable mold,it is necessary to replace the corresponding insert of the movable mold.To this end,through controlling the sequence of opening and closing actions of the mold,the movable mold slider and insert were moved together by a bent pin fixed on the stationary mold side of the first shot to obtain a replacement action between different inserts of the first and second shots.Then,the extension and retraction of the insert were controlled by limit blocks and return springs.To prevent the base plastic part from adhering to the stationary mold cavity during mold opening,a nitrogen spring-driven ejection mechanism for the base plastic part was designed on the stationary mold side of the first shot.To ensure the safe,accurate,and reliable operation of the automatic replacement of inserts,ejection,and other mechanisms,the corresponding safety mechanisms were designed.