机床机架呛火问题的防止措施

Measures to Prevent Boiling Defect of Machine Tool Body Frame

介绍了机床机架铸件的结构及技术要求,针对生产中出现严重的呛火问题进行了分析,采取了以下措施:(1)改进浇注系统,降低内浇道流速,使充型平稳,减少卷气;(2)采用倾斜浇方式,弥补大平面朝上排气不畅通的问题;(3)减少砂芯晃动,保证内腔砂芯中的气体通过上箱的气眼通畅地排到型腔外;(4)提高浇注温度,并将出气眼用封箱泥条围住,避免浇注时多余铁液从冒口溢出后倒灌到型腔里导致的严重呛火。经生产验证,改进措施有效,呛火问题得到解决。

The structure and technical requirements of machine tool body frame were introduced,the serious boiling defect occurring in production was analyzed,and following measures were adopted:(1)Improved gating system to decrease flowing velocity of ingate and stabilize mold filling,reduce gas involving.(2)Adopted slope pouring to offset poor venting caused due to big plane upwards.(3)Reduced sand core rocking to ensure the gas in inner sand cores to vent smoothly through the venting holes of top mold out from mold cavity.(4)Increased pouring temperature and enclosurred the venting holes with clay strips to avoid surplus iron liquid flowing backward into mold cavity during pouring and cause serious boiling.The production verification showed that the improving measures were effective,and the boiling problem had been solved.