摘要
发动机曲柄滑块机构是汽车中重要的传递力和位移的机构。以曲柄和连杆工作过程中产生的柔性变形为对象,研究对发动机动力性能带来影响。采用绝对节点坐标法,建立系统柔体动力学模型,分析曲柄和连杆在工作过程中的柔性变形对活塞运动位置的影响。利用发动机压缩比评价发动机动态性能,给出某型发动机压缩比计算公式,找到影响发动机压缩比的关键参数。利用MATLAB对曲柄滑块系统进行动力学仿真,分别考虑刚体和柔性体情况,计算活塞运动到上止点的位置,进而计算发动机压缩比。通过仿真结果比对表明,曲柄滑块的柔性变形减小了发动机压缩比,降低了发动机性能,不利于发动机的燃油经济性。
The slider-crank in engine is one of the important mechanisms in automobiles w hich transports force and displacement. The flexible deformation of the crank and the connecting rod w ill affect the dynamic performance of the engine. The flexible dynamic model of the engine slider-crank is established base on the absolute nodal coordinate formulation（ ANCF）. The influence of the flexible deformation on the displacement of the piston is studied. The equation w hich is used to calculate the engine compression ratio is given and the relationship betw een the compression ratio and the displacement of the slider is studied. The dynamic model of the system is simulated w ith the help of M ATLAB and the engine compression ratio of both rigid and flexible system is calculated. The results show that the flexible deformation of the system reduces the engine compression ratio and is not conducive to the engine fuel economy.
出处
《组合机床与自动化加工技术》
北大核心
2015年第6期1-4,共4页
Modular Machine Tool & Automatic Manufacturing Technique
基金
国家自然科学基金项目(61304013)
