对NN4102发动机气门摇臂在生产过程中出现气孔缺陷进行分析,从型壳的制作工艺、铸件的浇注工艺出发,找出了气孔缺陷的产生原因,并提出了相应的解决措施:一是增加型壳透气性,延长焙烧时间,提高焙烧温度;二是降低原料发气量;三是提高出炉温度及浇注温度;四是适当提高浇注速度,缩短浇注时间。结果显示,改进生产工艺后,气孔导致的缺陷率由原先的9﹪以上下降到2﹪左右。 Based on the analysis of the production process of NN4102 engine valve rocker arm, the causes of the blowhole defects were found out from the production process of the shell and the pouring process of the castings. Corresponding solutions were also put forward: First, Shell permeability, to extend the roasting time and improve the firing temperature; the second is to reduce the amount of raw gas; the third is to raise the temperature and casting temperature pouring; Fourth, an appropriate increase in casting speed and shorten the casting time. The results show that after the improvement of the production process, the defect rate caused by stomata dropped from above 9% to about 2%.