【作者】 房志军；

【导师】 蒋炎坤； 陈国华；

【作者基本信息】 华中科技大学 ， 动力机械及工程， 2005， 硕士

【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。更多还原

【Abstract】 In this paper, a crankshaft-connecting rod mechanism in LJ377MV gasoline engine of LJ750 autocycle is studied and designed, built in 3-D mode, and optimized through finite element analysis of its compose including piston, connecting rod and crankshaft. First, on base of the static calculation, and inflection and modal analysis of the crankshaft-connecting rod mechanism, the author applies finite element analysis method to the elastic contact between the connecting rod and the piston pin and the sliding bear bush and conventional static calculation of the compose 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 of crankshaft-connecting rod mechanism. By analyzing and acquiring the piston’s heat boundary condition in a similar mode, the author presents 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 on piston 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 and counterbalance shaft meet the requirements. Last, the paper also involves the dynamic analysis of the mechanism. And as an example, the static and dynamic calculation of the connecting rod are presented and compared, with the result showing that the dynamic calculation is superior to the static calculation.更多还原