双层不同类型螺纹盖双内螺纹脱模机构及模具设计

Design of Double Internal Thread Demoulding Mechanism and Injection Mould for Cap with Double Layer Different Type Threads

设计了一种盖子的双层脱螺纹机构及其模具,盖子中心孔内分上、下两层设置梯形内螺纹、细牙内螺纹特征。模具布局1模1腔,两板式单次开模。模架使用一种非标改装模架,无推板机构;为保证上、下螺纹型芯的同轴度,模架导向机构使用一种特殊的单导柱,在定模板、动模板上都设有配套双导套的单导柱导向机构。模腔的浇注采用潜伏式浇口以实现自动脱废料。针对上层梯形螺纹的脱模,采用油缸驱动齿条从而驱动内螺纹型芯转动,并由螺纹导向套进行转动控制的脱模方式。针对下层细牙螺纹的脱模,采用电机驱动螺纹型芯转动以实现螺纹脱模的方式。脱螺纹机构结构设置合理,动作可靠,成型效果良好,可为同类塑件的注塑生产提供有益借鉴,降低潜在设计风险。

A double-layer thread demoulding mechanism and its mould for the cover were designed.The central hole of the cover is divided into upper layer with trapezoid internal thread feature and lower layer with fine internal thread feature.Mould layout is one mould and one cavity,two plate single opening.A non-standard modified mould base was used without ejector plate mechanism.In order to ensure the coaxiality of the upper and lower thread cores,a special single guide pillar was used in the mould base guide mechanism,and single guide pillar guide mechanism matched with double guide bush was designed in both the fixed mould plate and the moving mould plate.The submarine gate was adopted in the mould cavity gating so as to remove waste runer automatically.Aimed at the demoulding of the upper trapezoidal thread,the oil cylinder was used to drive the rack for driving the inner thread core to rotate,and the rotation was controlled by the thread guide sleeve.In view of the demoulding of the lower fine thread,the motor was used to drive the thread core to rotate to realize the demoulding of the thread.The reasonable structure,reliable action and good molding effect of the thread demoulding mechanism can provide useful reference for the injection production of similar plastic parts and reduce the potential design risk.