摩托车发动机左盖压铸缺陷分析及成形工艺优化

Analysis of die-casting defect and optimization of forming process for left cover of motorcycle engine

针对摩托车发动机左盖成品率和生产效率较低的问题,利用铸造数值模拟软件Anycasting模拟了铸件压铸成形中金属液充型和凝固过程,分析了问题产生的原因。结果表明,金属液充型过程中存在涡流、卷气现象,铸件壁厚处存在孤立的液相区,导致铸件出现缩孔、缩松、气孔等缺陷;冷却系统设计的不合理延长了金属液凝固时间,影响了铸件生产效率。通过改变进料方式、优化内浇口和溢流槽、增加冷却水道和局部冷却等措施,铸件的成品率和生产效率得到了较大的提高。

The filling and solidification process in die-casting of the left cover of a motorcycle engine was simulated by using numerical simulation software Anycasting to analyze the defect cause and to solve the problem of relatively low qualified rate and production efficiency of the product. The results show that the main factors are the existence of eddy current and gas-volume phenomenon in the filling process of liquid metal and the existence of isolated liquid region in thick wall area, which leads to the defects of shrinkage cavity, porosity and pores, etc. The unreasonable design of cooling system extends the liquid metal solidification time that influences the production efficiency. The qualified rate and production efficiency of the product were increased by changing the feeding mode, optimizing the ingate and overflow tank, adding the cooling channel and local cooling.