【作者】 陈月蕾；

【导师】 于宝义；

【作者基本信息】 沈阳工业大学 ， 材料加工工程， 2011， 硕士

【摘要】 低压铸造是通过密封容器中的气体压力使金属液沿着升液管自下而上的填充铸件型腔,并且在铸件内的金属液凝固过程中,一直保持着金属液压力的铸造方法。这种工艺方法具有表面光洁,易于加工,节约造型材料,减少污染,工序简单,易实现机械化和自动化等优点。但是金属型低压铸造因为金属的散热系数高,凝固顺序不容易控制。本课题研究的铸件为特高压变电站用的大型铝合金传动箱箱体,成品件重量为270kg,且壁厚不均,薄壁15mm,厚壁260mm,加增大了设计和制造难度。首先对铸件进行工艺性分析,确定了铸件的分型面,并设计了一套包括直浇道、内浇道、横浇道的浇注系统,在此基础上进行了低压铸造充形及凝固过程的数值模拟。通过数值模拟,确定最优工艺参数,充型速度0.5m/s,浇注温度700℃,模具温度220℃。利用计算机数值模拟技术结果,得到了铸件各部位凝固的先后顺序趋势,通过在某些部位添加和调整冷铁,再反复进行模拟,根据模拟缺陷结果,优化了传动箱箱体铸件凝固过程的温度场；通过实际小批量生产检验,产品合格率达到90%,证明了模拟结果的正确性。计算机模拟技术应用到实际生产中,可以优化生产工艺,降低生产成本和生产风险,以最小的投入达到最大化的收益,提高市场竞争力。更多还原

【Abstract】 Molten metal is filling up the casting along the lifting tube from down to up under the gas pressure is called low pressure die casting. The molten metal is always under the gas pressure when it is solidification. This casting method is predominant than other methods. In this study, Low Pressure Casting Metal is used, under this improved casting method, the casting have high surface finish quality easy to machine; Use less molding materials, make less pollution. Manufacturing procedure is easy to achieve mechanization and automation. But the metal casting is not widely used because of the high coefficient of heat transfer of metal, hard to achieve the directional solidification.The casting in this study is a part of the UHV substation called transmission case made by aluminum. The weight of the casting is 270 kilograms. The wall thickness is 15 millimeter and 260 millimeter, so it hard to design and production. Based on the analysis and comparison on the mounding technique and structures technology, a transmission case is designed. Based on the gating system including sprue, cross gate and ingate, numerical simulation is used for fixing the technological parameters. The technological parameters are speed of mold-filling at 0.5m/s, pouring temperature is 700℃and mold temperature is 220℃.According to the result of computerized numerical simulation, analysed the feature of solidification, to design the cooling system to optimize the solidification process of the temperature field, reduce the casting defect. The result is used in the production. The casting was checked and accepted, proved the correct parameters. numerical simulation used into actual production, optimized the production process, reduced production costs and production risks, with a minimum investment to the maximize revenue, increase the market competitiveness.更多还原