柴油机气缸盖失效分析与疲劳评估  

Failure Analysis of a Cast Cylinder Head and Fatigue Safety Evaluation

作　　者：何晓东 罗颖迪 周海涛 王根全 胡定云 李鹏 He Xiao-dong;Luo Ying-di;Zhou Hai-tao;Wang Gen-quan;Hu Ding-yun;Li Peng(China North Engine Research Institute,Tianjin 300400,China)

机构地区：[1]中国北方发动机研究所,天津300400

出　　处：《内燃机与配件》2025年第2期46-49,共4页Internal Combustion Engine & Parts

摘　　要：气缸盖失效是制约柴油机整机寿命的重要因素。本文以某失效气缸盖为研究对象,分析失效原因,再评估其疲劳安全特性。研究发现:失效位置密集分布苞米粒状疏松,屈服强度、抗拉强度、延伸率分别降低了15%、16%、83%。将本体力学参数用于有限元分析,疲劳安全系数由1.20降低至1.05,低于经验安全阈值1.10。气缸盖疲劳失效,根本原因是缺陷严重。正向设计气缸盖时,基于修正的疲劳安全阈值1.26进行评价,结果更偏于可信、安全。The failure of cylinder head is an important factor restricting the life of diesel.This paper takes a failure cylinder head as the research object,analyzes the failure causes,and evaluates its fatigue safety characteristics.It is found that there were dense granular loose defects in the failure location.The yield strength decrease by 15%,the tensile strength and elongation decrease by 16%and 83%.Considering the real mechanical parameters,the fatigue safety factor at the failure point is recalculated,which is reduced from 1.20 to 1.05 and lower than the safety reading value of engineering experience 1.10.Fatigue lead to the failure of the cylinder head,and the casting defects serious is the root cause of failure.The revised fatigue safety threshold is 1.26.In the process of forward design of cylinder head,it is used to evaluate fatigue results,and the evaluation results are biased towards credible and safety.

关 键 词：气缸盖 断裂失效 缺陷 力学性能 疲劳安全特性 

分 类 号：U464.132[机械工程—车辆工程]