高强化柴油机气缸盖部件疲劳试验等效研究  

Study on Equivalence of Cylinder Head Component-level Fatigue Test for High-Strengthened Diesel Engine

作　　者：胡定云 周海涛 李鹏 张丽强 何晓东 HU Dingyun;ZHOU Haitao;LI Peng;ZHANG Liqiang;HE Xiaodong(China North Engine Research Institute(Tianjin),Tianjin,300400,China)

机构地区：[1]中国北方发动机研究所(天津),天津300400

出　　处：《小型内燃机与车辆技术》2023年第5期7-11,共5页Small Internal Combustion Engine and Vehicle Technique

摘　　要：针对某型高强化柴油机气缸盖台架试验中多次发生水腔与气道壁之间贯穿性断裂问题,建立了气缸盖热机耦合有限元模型,计算了气缸盖失效部位的温度、机械应力、热应力及热机耦合应力,分析影响该型气缸盖疲劳的主要因素。结果表明,失效位置由热载荷引起的拉应力高达89MPa,是造成失效的主要原因。因此在部件疲劳试验时,提出来在喷油器安装位置施加预紧力来补偿热应力,并分析了预紧力对失效位置应力的影响规律,采用疲劳安全系数等效的方法确定了预紧力的大小。在部件疲劳试验台上进行了气缸盖疲劳试验,开裂位置与整机考核故障一致,实现了整机试验故障在部件疲劳试验中复现。In view of the problem that the run-through fracture between the water jacket and intake port wall of the aluminum cylinder head in a highly intensified diesel engine happened several times in bench tests,cylinder head engine finite element model,which is coupled with thermal and mechanical load,was established.And the failure part′s temperature,stress,mechanical stress,thermal stress and thermal-mechanical coupling were calculated,the main factors affecting the fatigue of this type of cylinder head were analyzed.The results show that the tensile stress of failure location caused by thermal load is up to 89 MPa,which is the main cause of failure.Therefore,in the component fatigue test,it is proposed to apply preload to the installation position of fuel injector to compensate the thermal stress,and analyze the influence law of preload on the stress of failure position,and determine the size of preload by using the method of equivalent fatigue safety factor.The cylinder head fatigue test has been carried out on the component fatigue test bench,and the cracking position is consistent with the inspection fault of the whole machine,which realizes the reoccurrence of the whole machine test fault in the component fatigue test.

关 键 词：高强化 柴油机 气缸盖 热应力 疲劳开裂 安全系数 

分 类 号：TK423.2[动力工程及工程热物理—动力机械及工程]