摘要
介绍了汽车发动机干式缸套缸体的生产情况,对立浇工艺生产的铸铁缸体缸筒壁厚不均匀问题进行了大量的分析,认为产生缸筒壁厚不均匀的原因主要为:单薄的水套芯热膨胀受力变形,水套芯高度的影响,浇注呛火,浇注时间过长以及水套芯组装偏移失控。采取了以下措施,解决了缸筒壁厚不均匀问题:(1)选用含一定比例宝珠砂的低膨胀高强度覆膜砂制作水套芯;(2)将覆膜砂灼减量控制在2%以内,并设置好水套芯的排气通道和做好烘干、浇注引火工作;(3)合理设计浇注系统,实现平稳快速充型;(4)保证水套芯与缸筒芯组合正确,没有偏移,最好采用组芯胎具工装。
The produetion situation of cylinder block of automotive engine with dry cylinder liners was introduced. A great deal of analysis works was conducted on the problem that the cylinder wall thickness of the vertically-east gray iron hloek had been uneven,and it was considered that the main reasons causing uneven wall thickness of the cylinder holes were as follows:the thin and weak water jacket core was distorted due to the thermal expansion fi)rce;influenee of the height of water jacket core;boiling during pouring process;pouring time was too hmg and displacement of water cores assembling lost control. The problem of uneven cylinder wall thickness was solved by adopting following measures:( 1 )Using proportional pearl sand- eonlaining low expansion and high streugth resin-coated sand to make water jacket core.( 2 )Controlling the LOI of the resin- coated sand less than 2%,properly setting the venting canal and thoroughly drying the water jacket core,as well as conduct- ing instantly gas-ignition during pouring. (3)Designing proper gating system to realize stable t?tst mohl filling.( 4 )Assuring the water jacket core and cylinder hole cores to be correctly assembled without deviation and it was suggested to nse the die equipment for assembling.
作者
刘增林
LIU Zeng-lin(Chengdu Tonglin Casting Industrial Co.,Ltd., Chengdu 611330, China)
出处
《现代铸铁》
CAS
2017年第4期42-46,共5页
Modern Cast Iron
关键词
灰铸铁
缸体
立浇工艺
壁厚不均匀
gray iron
cylinder block
vertical casting method
uneven wall thickness