覆砂铁型铸造缸体气缩孔的防止措施  

Measures to Prevent Blowhole-shrinkage Defect of Cylinder Block Cast with Sand-covered Iron Mold

作　　者：刘水兵 覃丹枫 徐婵 LIU Shui-bing;QIN Dan-feng;XU Chan(Guangxi Yuchai Machinery Parts Manufacturing Co.,Ltd.,Yulin 537005,China)

机构地区：[1]广西玉柴机器配件制造有限公司,广西玉林537005

出　　处：《现代铸铁》2021年第5期27-30,共4页Modern Cast Iron

摘　　要：介绍了国6干式缸套发动机缸体铸件的结构和覆砂铁型铸造工艺,并对缸体的最高点凸台及周边出现的气缩孔进行了原因分析,采取了以下措施:(1)改变铸造工艺布局,将上下型翻转;(2)构筑砂芯排气通道,增强铸型分型面的排气能力;(3)缩短单箱浇注时间,将直浇道、横浇道及内浇道的截面积分别由1963 mm^(2)、2344 mm^(2)、2704 mm^(2)调整为2375 mm^(2)、2876 mm^(2)、4200 mm^(2),单箱浇注时间控制在14~17 s。生产结果显示:共生产了2500件缸体铸件,综合废品率≤3%,最高点凸台及周边的气缩孔缺陷数量为0,有效防止了该缺陷的产生。The cylinder block casting structure of China 6-th vehicle emission standard and resin sand-covered iron mold casting process were introduced,and the reason caused the blowhole-shrinkage defects occurring at most high boss and its periphery was analyzed.Following measures were adopted:(1)Casting method scheme was changed,the top semi-mold and bottom semi-mold were exchanged each other.(2)Venting passageway was set for the sand core,the parting face venting capacity of the mold was increased.(3)The sectional areas of the sprue,runner bar and ingates were increased from 1963 mm^(2),2344 mm^(2),2704 mm^(2) to 2375 mm^(2),2876 mm^(2),4200 mm^(2) respectively,the pouring time per mold was controlled in the range of 14~17 s.The production result showed:a total of 2500 cylinder block castings were produced,the integrated waste rate was of≤3%,the number of blowhole-shrinkage defects occurring at most high boss and its periphery was zero,this type defect had been effectively prevented.

关 键 词：灰铸铁 缸体 气缩孔 

分 类 号：TG251[金属学及工艺—铸造]