LJ377MV汽油机曲柄连杆机构的设计及有限元分析.pdf

II 摘要本文面向工程应用以洛阳北方企业集团公司LJ750摩托车产品开发与研究为背景对LJ377MV汽油机曲柄连杆机构进行了设计和研究简要阐述了曲柄连杆机构主要部件及发动机平衡轴的设计过程建立了曲柄连杆机构的三维实体模型并进行了相应的有限元分析和计算首先在对连杆进行静力学屈曲和模态分析的基础上将弹性接触问题的有限元法应用于工程实际的连杆接触计算中并与传统的连杆静力学有限元方法进行了比较表明弹性接触问题的研究方法是曲柄连杆机构研究中比传统静力学方法更为有效的研究方法其次利用相似机型得到的活塞热边界条件完成了活塞的有限元计算与分析获得了活塞的温度及其应力分布特性并应用活塞环三维流动动压润滑分析模型研究了活塞环几何结构设计参数等对活塞润滑性能的影响再次对发动机曲轴和平衡轴进行了设计和分析应用有限元法对曲轴及平衡轴进行了静力学和模态计算与分析结果表明所设计的曲轴及平衡轴满足设计要求最后在上述基础上对曲柄连杆机构进行了动力学研究并以连杆为例对其动力学和静力学计算结果进行了对比分析结果表明动力学计算与静力学相比更为优越关键词发动机曲柄连杆机构有限元动力学分析 III Abstract In this paper, acrankshaft-connecting rod mechanism inLJ377MV gasoline engine of LJ750 autocycle is studied and designed,built in 3-D mode, and optimized through finite element analysis of pose including piston, connecting rod and crankshaft. First, on base of the static calculation, and inflection and modal analysis of the crankshaft-connecting rod mechanism , theauthor applies finite element analysis method to the elastic contact between theconnecting rod and the piston pin and the sliding bear bush and conventional static calculation of pose in the above virtual engineering question. Comparison between elastic contact result and static result shows the elastic contact method is more effective in the study ofcrankshaft-connecting rod mechanism . By analyzing and acquiring the piston’s heat boundary condition in a similar mode,the authorpresents the temperature and stress field display characteristic of the piston using finite element calculation software. Through the analysis of the piston ring’s 3-D fluid dynamic stress lubrication mode, its geometric design parameter’s impact onpiston design lubrication performance is investigated. Second, the design, and static and modal analysis of the crankshaft and counterbalance shaft are presented. The result shows the designed crankshaft andcounterbalance shaft meet the requirements. Last, the paper also involves the dynamic analysis of themechanism .And as an example, the static and dynamic calculation of theconnecting rod are