基于有限元分析下缸盖提升量对气缸垫压筋疲劳问题的影响与研究  

Research on the Influence of the Lifting Distance of Cylinder Head on the Fatigue of Cylinder Head Gasket Rib Based on Finite Element Analysis

作　　者：孙亚东 杨沫 孙祺翔 熊小建 肖翔 刘玉铭 SUN Yadong;YANG Mo;SUN Qixiang;XIONG Xiaojian;Xiao Xiang;LIU Yuming(Ningbo Geely Royal Engine Components Co.,Ltd.,Ningbo,Zhejiang,315336,China)

机构地区：[1]宁波吉利罗佑发动机零部件有限公司,浙江宁波315336

出　　处：《小型内燃机与车辆技术》2022年第6期29-34,共6页Small Internal Combustion Engine and Vehicle Technique

摘　　要：气缸垫广泛应用于汽车发动机缸体与缸盖间密封,由于燃烧爆压引起缸体缸盖变形,使得压筋遭受疲劳考验。目前在CAE分析中,评价缸体缸盖变形量的指标是缸盖提升量,但是由于分析中往往重点关注的是密封压力,同时目前行业关于缸盖提升量的研究较少,为分析缸盖提升量(变形量)对压筋疲劳的影响,同时提出可行性的解决方案。为此分析了缸盖提升量的形成与影响因素及缸体缸盖变形量的差异,同时借助有限元分析解决气缸垫压筋疲劳开裂问题。研究表明,气缸垫压筋疲劳的主要影响因素是缸体缸盖的变形程度,缸体缸盖变形呈现两端变形大,中间变形小,距离爆压中心点越远,变形越小。同时,当缸体为铸铁,缸盖为铸铝时,缸体变形小于缸盖,当同为铸铝材质时,则缸盖变形小于缸体。通过对某发动机气缸垫开裂区域缸体缸盖进行优化,密封压力由10.3 N/mm提升至11.4 N/mm,改善10.7%,缸盖提升量由25.2μm下降至24.7μm,改善2.0%。同时解决压筋疲劳问题,可通过优化压筋尺寸、加强缸体缸盖结构、局部增加支撑筋、增加缸垫层数等来实现。旨在通过分析缸盖提升量对气缸垫压筋疲劳的影响为提出可实现的方案提供支持。Cylinder head gasket is widely used in the sealing between cylinder block and cylinder head of automobile engine. The deformation of both of them caused by combustion explosion pressure testes the rib fatigue. At present, the index to evaluate the deformation of cylinder block and cylinder head in CAE analysis is the lifting distance of cylinder head, but the analysis often focuses on the sealing pressure. At the same time, there is little research on the lifting distance of cylinder head in the industry, in order to analyze the influence of lifting distance(deformation) on rib fatigue, a feasible solution is proposed. This paper mainly analyzes the formation and influence factors of lifting distance of cylinder head and the difference with cylinder block and cylinder head. At the same time, the FEA is used to solve the problem of rib fatigue cracking of cylinder head gasket. The results show that the main influencing factor of rib fatigue is the deformation degree of cylinder block and cylinder head, the deformation of both is large at both ends and small in the middle, the farther away from the center of explosive pressure, the smaller the deformation. When the cylinder block is of cast iron and the cylinder head is of cast aluminum, the deformation of cylinder block is smaller than that of cylinder head, when the both are of aluminum materials, the deformation of cylinder block is larger than the cylinder head. By optimizing the cylinder block and cylinder head in the cracking area with cylinder head gasket rib, the sealing pressure is increased from 10.3 N/mm to 11.4 N/mm, an improvement of 10.7%, and the lifting distance of cylinder head is reduced from 25.2 μm to 24.7 μm,an improvement of 2.0%. So the rib fatigue could be solved, it can be achieved by optimizing the size of rib, strengthening the structure of the cylinder head and cylinder block, increasing the support rib and the number of gasket layers. The purpose of this paper is to analyze lifting distance of cylinder head, and provide support for th

关 键 词：气缸垫 燃烧爆压 压筋疲劳 缸盖提升量 有限元分析 

分 类 号：U464.132[机械工程—车辆工程]