打印机滚筒导板多点浇口注塑模设计

Design of injection mould with multiple pin-point gates for printer drum guide plate

针对打印机滚筒导板塑件的工业设计结构特点及使用改性合金聚碳酸酯/丙烯腈-丁二烯-苯乙烯塑料成型的生产要求,设计了一副多点点浇口三板模具用于该塑件的注射成型。模具中的模腔布局为一模一腔,以使塑件成型精度控制在MT3~4级。不同于常规三板模具,在该模具中采取了以下设计措施来保证塑件的成型要求:一是通过主导柱、副导柱、模仁定位锥台等的设置,保证了塑件基本成型尺寸的成型精度;二是通过增加镶件排气措施、优化注射成型工艺参数等措施,有效降低和控制了塑件成型后的变形量,保证了塑件的成型形状精度,所增设的成型镶件有益于模腔排气,镶件间隙小于0.02 mm,镶件设计时须设计孔边扩距为1 mm,以降低镶件配模难度,避免镶件间隙飞边发生;三是为提高流道废料和塑件的冷却效率,脱料板中开设有2条?10 mm冷却水路,模腔成型件中开设有10条?10 mm冷却水路。模具中还设置了2个斜导柱滑块侧抽芯机构用于塑件两侧端面的脱模,塑件的最终脱模由多根顶针均衡顶出脱模。

A three-plate mould with multiple pin-point gates was designed for injection molding of the printer drum guide plate plastic part based on its structural characteristics of industrial design and production requirements using modified alloy polycarbonate/acrylonitrile-butadiene-styrene plastic molding.The cavity layout in the mould was one mould with one cavity,so as to control the molding precision of the plastic parts at MT3-4 level.Unlike conventional three-plate moulds,the following design measures were taken in this mould to ensure the molding requirements of the plastic parts.The first was to ensure the forming accuracy of the basic forming dimensions of the plastic parts by setting up the main guide pillar,auxiliary guide pillar,and mould core positioning cone platform,etc.The second was to effectively reduce and control the deformation of the plastic parts after forming by increasing the air vent measures of inserts and optimizing the injection molding process parameters,ensuring the accuracy of the forming shape of the plastic parts.The added formed inserts were beneficial for the air vent of the mould cavity,and the gap between the inserts was less than 0.02 mm.When designing inserts,it was necessary to design a hole edge expansion distance of 1 mm to reduce the difficulty of mould matching and avoid the occurrence of flash in the gap between the inserts.Thirdly,in order to improve the cooling efficiency of waste materials and plastic parts in the flow channel,there were 2 cooling water channels with a diameter of 10 mm in the stripper plate,and 10 cooling water channels with a diameter of 10 mm in the mould cavity formed parts.Two angle pin slider side core pulling mechanisms were also installed in the mould for demoulding the two end faces of the plastic part.The final demoulding of the plastic part was evenly ejected by multiple ejectors.