大型复杂球铁铸件滑枕充型过程数值模拟

Numerical Simulation on Liquid Filling Process of Large Complex Ductile Iron Casting

以实际生产高档数控机床关键零部件滑枕的几何尺寸和工艺方案为依据,建立三维网格模型,计算相应边界条件,设计了三种不同的浇注系统方案,采用有限元模拟软件Procast对充型过程中液体流动进行数值模拟。结果表明,立浇底注工艺条件下,数值模拟的充型时间与生产实际基本相符,充型过程不平稳,铸件顶部布置高压油孔的厚大部位出现了搅动的液流,与生产实际相比较,这个部位正是出现缺陷最多的地方。出气冒口减小充型阻力,加快金属液的充型速度,有利于合金液大流量的快速浇注;而设置冷铁,搅动的液流现象有所减轻。

The establishment of three-dimensional grid model and calculation of the corresponding boundary conditions are based on the the geometry and technology programs in producting crucial parts of high-end CNC machine tools, and desiged three different filling progresses to take the finite element simulation software Procast to simulat the fluid flow. The result shows that, during the process of vertical pouring at the bottom of the casting, The filling times are according with the actual producing time. But the filling process is bumpy and stirred flows of liquid metal occurred at the top of the casting which is layout many high-pressure oil holes and have many defects in production. The resistance of filling can be reduced and the velocity of liquid metal can be speeded up. The phenomenon of stirred flows of liquid metals can be reduced by the arrangement of cold iron.