发动机缸体断芯缺陷原因分析及防止措施

介绍了公司目前所使用的造型线及不同砂芯所采用的制芯设备,阐述了NGS缸体的砂芯组成及在砂型中装配情况,并利用鱼骨图对水套F40面侧壁断芯、热油道断芯和水套爪断芯这3种类型的断芯原因进行分析,在铸件结构、覆膜砂材料、芯盒结构和制芯工艺等方面进行了改进。生产验证结果表明:通过对芯盒清理、维护保养及过程质量等方面进行严格控制,水套侧壁断芯、水套爪断芯和油道断芯的产生几率明显降低,缸体的废芯率已从原来的1%降低至现在的0.2%左右。

Cores Breaking Reason Analysis and Prevention Measures of Engine Cylinder Block

The molding lines and core-making equipments for different sand cores used at present in author＇s company were introduced.The cores assembly and their placement in the mold of NGS cylinder block were described.By using fish bone figure,the reasons causing side wall breaking on F40 side of the jacket core,hot oil channel core breaking and jacket core claw breaking were analyzed,and relevant improvements were conducted with the casting configuration,materials of resin-coated sand,core box structure and core-making process.The result of production proof-test showed that by strictly controlling cleaning,maintenance of the core box as well as the process quality,the breaking possibility of the jacket side core,jacket claw core and oil channel core were obviously reduced,and the core rejection rate of the cylinder block has been decreased from original 1％ to about 0.2％.