盖壳体形体要素与缺陷预期分析及注射模设计

Analysis of Body Elements and Defects of Cover Shell and Design of Injection Mold

通过对盖壳体形体要素分析,其具有凹槽、凸台和外观要素。盖壳体在注射模中竖立摆放,分型面设置在底面。若浇口也设置在底面,根据缺陷预期分析,塑料熔体为逆流填充而产生填充不足、气泡、过热痕、流痕和银丝等缺陷。因此,塑料熔体必须采用顺流填充,将模具潜伏式点浇口设置在盖壳体上部。如此,上述缺陷复不存在,并能满足外观要求。注入潜伏式流道的塑料熔体,借助顶杆上的点浇口进入模具型腔。依靠拉料杆可将主流道中冷凝料拉脱模,应用顶杆可顶脱分流道和潜伏式流道中冷凝料。在顶杆顶脱盖壳体的同时,使得附在顶杆中的点浇口冷凝料能自行掉落。该浇注系统缩短了浇注系统的长度,避免了使用热流道,这种浇注系统和脱模结构具有一定的使用价值。

Through the analysis of the body elements of the cover shell,it has grooves,boss and appearance elements.The cover shell is placed upright in the injection mold,and the parting surface is arranged on the bottom surface.If the gate is also set on the bottom,according to the defect expectation analysis,the plastic melt will produce defects such as under-filling,bubbles,overheating marks,flow marks and silver wire for countercurrent filling.Therefore,the plastic melt must be filled with the downstream flow,and the mold latent point gate is arranged on the upper part of the cover shell.In this way,the above defects do not exist and can meet the appearance requirements.The plastic melt injected into the latent runner enters the mold cavity through the point gate on the ejector rod.The condensing material in the main channel can be pulled and demoulded by the drawing bar,and the condensing material in the shunt channel and the latent channel can be removed by the jacking bar.When the ejector rod ejector removes the cover shell,the point gate condensate attached to the ejector rod can fall off by itself.The casting system shortens the length of the casting system and avoids the use of hot runner.This gating system and demoulding structure have universal use value.