摘要气缸盖是发动机所有零件中中结构最复杂的零件之一，燃烧室空间是由活塞顶和气 缸壁共同构成。气缸盖的工作环境很恶劣，气体冲击力和螺栓预紧力共同作用于它。同 时，气缸盖也共同承受着较大的机械应力和热应力。83966

对气缸盖的温度场、机械和热应力场以及热机耦合应力场进行正确的分析是气缸盖 结构设计改进的基础。采用有限元分析法可以有效缩短缸盖产品的设计周期，推进缸盖 的优化升级。

本文对 4F20 柴油机缸盖进行 ANSYS 的有限元分析。首先用 PRO/E 软件建起缸盖 的三维实体模型；再用 ANSYS 软件对上述缸盖三维实体模型进行网格划分，建起了缸 盖的有限元模型；在用数值分析法对缸盖进行有限元分析，计算缸盖的温度场、机械和 热应力场、热-机耦合应力场，应用其结果对缸盖的寿命进行分析。最后，针对如何延 长缸盖的使用寿命提出修改建议。

通过软件计算，结果表明缸盖的受热面鼻梁区、气缸盖气门座圈接触面的应力较大。 在气缸盖的设计过程中，我们应该着重考虑上述几个区域。缸盖鼻梁区同时也受着几个 力的综合力的作用，这些力使得其获得较大的应力，易发生疲劳损坏。

毕业论文关键词：气缸盖；温度场；机械应力场；热应力场；热-机耦合应力场

ABSTRACT The cylinder head is one of the most complex parts of the engine。 The chamber is composed of piston crown and the cylinder wall。 The cylinder head has a bad working environment , and impact force of the gas and bolt pretightening effect on it。 At the same time, the cylinder head also has to bear the larger mechanical stress and thermal stress。

The correct analysis to the temperature field, mechanical stress field ,thermal stress field,thermal and mechanical coupling stress field is the based。of cylinder cover structure design。The design cycle can be effectively shorten by using finite element analysis method, it can promote the optimization and upgrading of cylinder head。 In this paper, the finite element analysis by ANSYS are used on the cylinder head of F diesel engine。 First of all,we use Pro  / E software to built 3D entity model of the head。Secondly,we use ANSYS software to draw the mesh of three-dimensional solid model of the cylinder head and to build the finite element model of the cylinder head; Additionly we  get  the  temperature  field,  mechanical  stress field ,thermal stress field,thermal and mechanical coupling stress field by numerical analysis, and the analysis results is important to the life analysis of the cylinder head。 Finally, I give some advice in order to prolong the service life of the cylinder head。

In this paper, the finite element analysis by ANSYS are used on the cylinder head of F diesel engine。 First of all,we use Pro / E software to built 3D entity model of the head。Secondly,we use ANSYS software to draw the mesh of three-dimensional solid model of the cylinder head and to build the finite element model of the cylinder head。Additionly we get the temperature field, mechanical stress field ,thermal stress field,thermal and mechanical coupling stress field by numerical analysis, and the analysis results is important to the life analysis of the cylinder head。 Finally, I give some advice in order to prolong the service life of the cylinder head。

The software calculation results show that the stress on the bridge zone , the contact surface of valve seat is very big 。 In the design process of the cylinder head, we should focus on these several areas。 Bridge zone of cylinder head should bear several integrated force。These forces are easy to lead fatigue damage。

Keywords: the cylinder head; the temperature field; mechanical stress field;thermal stress field;thermal and mechanical coupling stress field