【摘要】 以4缸内燃机为例,在建立三维装配实体的基础上,采用有限元法对曲轴轴系和机体进行了动特性分析。在建模中充分考虑了实际约束条件,并对关键部件的接触问题做了处理。计算采用系统级的动特性分析方法获得了曲轴轴系的扭转、弯曲、伸缩振动及其复合振动,显示出了曲轴轴系和机体各部件振动特性。结果表明该系统的模态密集,频率范围很宽,对于发动机工作过程中产生的宽带激励信号,比较容易引起曲轴轴系的振动。更多还原

【Abstract】 The 3D assembly model of a fourcylinder engine with the crankshaft system and block is established, actual restrictions and contact areas of key parts have been considered in model construct, and then the dynamic characteristics of system level have been carried out by FEM method. The calculation about the torsion, bend, flexibility and compound vibration shows vibration characteristics of the crankshaft system and block, and it indicates that the system has dense modes and broadly frequency response, giving rise to the vibration of the crankshaft system with the broad band input signal.更多还原