【作者】 陈建荣；

【导师】 张如华； 蒋兴宏；

【作者基本信息】 南昌大学 ， 材料加工工程， 2011， 硕士

【摘要】 当前,塑料工业快速发展,塑料制品应用的范围越来越广,工业产品及日常用品塑料化程度越来越高。但注塑成型时常出现一系列的质量问题,比如产生熔接痕、填充不足、翘曲变形和尺寸误差等缺陷。特别是对于大型薄壁注塑件,如何预防塑胶制品翘曲是经常困扰工程师的一个难题。如果单凭经验来设计注塑模具,往往不能得到最优化的设计方案,揣测猜想成分增加,设计是否合理则要通过实际试模来验证。这将导致试模不合格后反复修模,有时还得不到最优化设计方案。本文首先简要概述了大型精密注射模具设计与制造技术,在聚合物流变学理论的基础上,进而分析翘曲变形的产生机理及影响的主要因素。在此基础上,以某品牌大型薄壁冰箱压缩机罩塑件为研究对象,运用注塑模具CAE软件Moldflow对塑料熔体在模具型腔中的保压、填充、锁模力、模腔残余应力、熔接痕及翘曲变形等各个阶段进行了模拟分析,通过对不同浇注系统模拟的对比分析,得出浇注系统的优化设计方案。针对冰箱压缩机罩在试模过程中出现的翘曲变形问题,运用正交设计法设计了一个L18的正交试验,研究注塑成型工艺参数(熔料温度、模具温度、保压压力、注射时间、保压时间、冷却时间)及其交互作用对翘曲变形的影响度,得到翘曲变形最小的工艺参数组合。然后用得出的最优注塑成型工艺参数组合,通过CAE模拟试验及生产实验验证了最优注塑成型工艺参数组合能明显减小翘曲变形。模具的成型工艺以及整体模具结构确定后,通过Pro/E的建模模块、模具设计模块及工程图模块对模具进行三维设计。最终实现了冰箱压缩机罩模具的整体三维设计,并完成模具装配图及各零件的工程图的转换。通过将CAD/CAE技术引入注塑模具设计特别是大型薄壁注塑模具设计中,能够大大提升塑胶制品的质量,提高生产效率。更多还原

【Abstract】 At present, with the development of plastics industry, the application of plastics have extended larger and larger, specially in the sphere of industry and ordinary product。But injection molding often results many product problems such as short shots、weld line、warp、dimension error and so on。How to decrease the plastics warp is a puzzle for engineer specially to the thin-wall and large-size product。If injection mold is designed only by experience on gating and cooling system。Usually it is not optimized and contain guessing besides factors, this design will have to be done again, which may be a long and reduplicative progress and possibly the best result can no be got。In this paper, firstly provides the technology of mold design and manufacture to the large-size and precise injection molding。Describes the generation mechanism of warpage and analyze the factors that affect the warpage based on theory of flowing of the polymer。On this foundation, taking a thin-walled refrigerator shell part for example, when use mold CAE software Moldflow, simulat about the filling、packing、clamp force、residental stress、weld line、warp and so on。Through comparing simulating result to the different of gating system, then get the best gating system scheme。To solve the warpage problem of the refrigerator shell in mold trial, arrange the simulation according to orthogonal experiment theory, the L18 orthogonal experiment table is designed, the warpge data are obtained under different molding conditions (mold temperature、melt temperature、injection time、packing pressure、packing time、cooling time), and obtain the optimum set of factors。Then use this optimum set of facrors, the result show the optimum set of factors can be effectively reduce the warpage oAfter define the injection process and the whole structure of the mold, through using the molding module、mold design and the drawing module of the software Pro/E realize the 3D mold design。Finally to finish the mold design of the refrigerator shell。Through using the CAD/CAE technology in design of injection mold specially the thin wall and large size injection mold。We can improve the quality of the product and productivity effect。更多还原