电动客车水冷机壳低压铸造工艺设计与优化

Design and Optimization of Low-pressure Casting Process for Water-Cooled Casing of Electric Bus

针对电动客车电动机壳体直径较大、内壁筒状水套范围广和壁厚不均匀等特点,分析了水冷机壳的复杂结构及筒状砂芯对铝合金低压铸造顺序凝固的影响。设计了低压铸造浇注系统、模具结构和工艺参数。通过AnyCasting软件模拟铸件凝固过程,预测壁厚不均匀产生的热节和砂芯分隔作用形成的孤立液相情况,以及由此引发部分位置容易出现的缩松、缩孔等缺陷。探究如何采用铍铜镶件、水冷镶件和气冷管等优化措施调整凝固速度,提高铸件内部组织成形致密度及生产质量。

According to the characteristics of large shell diameter,wide range of inner barrel water jacket and uneven wall thickness for housing of electric bus motor,the influence of the complex structure of the water-cooled housing and the barrel-shaped sand core was analyzed on the sequential solidification of aluminum alloy low-pressure casting.Low pressure casting pouring system,mold structure and process parameters were designed.By using the AnyCasting software,the casting solidification process was simulated to predict the isolated liquid phase formed by the hot spot and the sand core separation caused by uneven wall thickness,which lead to defects such as shrinkage and cold shut in some locations.The solidification speed was optimized by adopting beryllium copper inserts,water-cooled inserts and air-cooled pipes to improve the soundness and production quality of the internal structure of the die casting housing.