基于数值模拟的汽车后悬梁压铸成型工艺设计

Design of Die-casting Moulding Process for an Automotive Rear Suspension Beam Based on Numerical Simulation

铝合金压铸由于其轻量化和高效率生产等优点,在新能源汽车零部件开发中得到广泛应用。随着汽车领域对铸件高性能的要求,需要设计合理的压铸工艺,有效控制卷气、夹渣、缩孔等常见压铸缺陷,才能达到产品质量要求。本文以壁厚不均的汽车后悬梁压铸件为研究对象,通过数值模拟对比分析了2种浇注系统方案,并针对铸件生产中存在的缩孔问题进行分析,提出改进方案。结果表明,采用五浇口的方案可以缩短铝液充填距离,减少卷气和氧化夹杂等缺陷。针对远离内浇口的2处厚壁位置存在的缩孔问题,提出模具镶嵌铜合金块的方案,数值模拟结果表明高导热的CuCoBe嵌件可以加快厚壁处铝水冷却速度,有效消除热节和缩孔。

Aluminium alloy die casting has been widely used in the development of new energy vehicle parts due to its advantages of lightweight and high-efficiency production.However,considering the high performance requirements of castings in the automotive field,it is necessary to design a reasonable die-casting scheme to effectively control common die-casting defects such as gas porosity,inclusions,and shrinkage holes to meet product quality requirements.In this paper,taking the die-casting parts of automobile rear suspension beams with uneven wall thickness as the research object,the two gating system schemes were compared by numerical simulation,the casting defects existing in production were analysed,and an improvement scheme was proposed.The results show that the five-gate scheme can shorten the filling distance of molten aluminium and reduce defects such as entrained air and oxidation inclusions.Aiming at the shrinkage hole problem of the two thick walls far away from the inner gate,a scheme of inserting copper alloy blocks in die was proposed.The numerical simulation results show that the cooling rate of aluminium melt at the thick walls can be accelerated by a high thermal conductivity CuCoBe mould insert,and the hot spot and shrinkage holes can be effectively eliminated.