发动机主轴承盖断裂问题分析研究  

Analysis and Research on Fracture Problem of an Engine Main Bearing Cover

作　　者：姜广梅 张楠 Jiang Guang-mei;Zhang Nan(BYD Automobile Industry Co.,Ltd.,Guangdong Shenzhen 518000)

机构地区：[1]比亚迪汽车工业有限公司,广东深圳518000

出　　处：《内燃机与配件》2024年第21期78-80,共3页Internal Combustion Engine & Parts

摘　　要：在发动机耐久试验过程中,发动机铝合金整体式主轴承盖发生断裂失效。针对该问题,对断口进行电镜分析,发现断裂位置在模具顶针处,断口金相组织存在异常;对主轴承盖进行强度、疲劳仿真分析,结果发现其最小疲劳安全系数正是断裂位置,疲劳系数不满足要求。综合分析由于主轴承盖本体结构设计缺陷和铸造缺陷,导致本体强度不满足要求;并且由于顶针位置布置在疲劳系数最小位置,导致裂纹源产生,进而导致主轴承盖断裂。对主轴承盖结构及对铸造工艺进行优化,经过反复优化验证得到最优设计方案。通过发动机耐久试验验证最终解决主轴承盖断裂问题。During the engine durability test,an aluminum alloy integral main bearing cover of engine broke.For this problem,electron microscopy was used to analyse fracture,some cracks were found at the thimble of the mold.In addition,metallurgical structure of the fracture was abnormal.Simulate the strength and fatigue of the main bearing cover,and then the results showed that the minimum fatigue safety factor was the fracture position and the fatigue factor did not meet the requirements.Comprehensive analysis showed that the strength of the main bearing cover body did not meet the requirements due to structural design defects and casting defects,and the thimble position was located at the position with the minimum fatigue coefficient,which led to the crack sources,then causing the main bearing cover to break.After optimizing structure and casting process of the main bearing cover,the strength as well as fatigue analysis are carried out in the same method.Experiencing reiterative optimization and verification,the optimal design scheme is obtained before the engine durability test proves that the main bearing cover fracture problem is finally solved.

关 键 词：发动机 主轴承盖 抗拉强度 仿真分析 

分 类 号：TH133.3[机械工程—机械制造及自动化]