笔尖注塑模螺纹脱模机构的优化设计

根据笔尖结构为锥形并需要内螺纹脱模的特点,分析和比较了目前模具采用的自动脱螺纹机构。对笔尖内螺纹部分设计三段轴向开槽,优化笔尖结构,设计了二次推出不带旋转机构的自动脱螺纹注塑模。型芯部分由1个型芯和1个三角套组合而成,通过三角套与型芯组件的相对运动,使三角套内缩以实现自动脱螺纹。同时采用二次推出机构完成整个注塑件的脱模,由于模具脱模部分不需要设置旋转机构,简化了模具结构,缩短了开模时间。

OPTIMIZATION DESIGN OF AUTOMATIC THREADS DEMOULDING MECHABNISM OF INJECTION MOULD FOR PEN TIP

According to the characteristic of pen tip parts with cone-shape and needing internal threads ejecting mechanism,the current dies of automatic thread are analyzed and compared.Througn designing three axial slots in internal threaded portion and optimizing nib structure,a design was made on the injection mould with a two-step ejecting mechanism with non-rotating.The forming core consisted of a small core and a triangle sleeve,through the relative motion between triangle sleeve and the small core,the triangle sleeve began to shrink and the thread automatically escaped.Simultaneously two-step ejecting mechanism were used to complete ejection,because ejecting elements did not need to establish the rotary mechanism.This design simplified the mold structure and reduced the mold time.