分析了1.5升三缸直列涡轮增压缸内直喷发动机的曲轴系统的曲轴刚度和主轴承间隙对发动机NVH性能的影响。首先,建立发动机部件的有限元模型,并在多体动力学软件AVL中计算在不同工况时不同的参数情况下的动力学响应;其次,对三种不同材料的曲轴进行了模态分析,探究其机械结构的固有振动特性以及模态频率与发动机转速和阶次的关系;最后,计算了发动机外表面法向积分速度级和声功率级,并以其作为评价标准。 The influence of crankshaft stiffness and main bearing clearance on the engine NVH performance of 1.5-liter three-cylinder direct-injection turbocharged direct injection internal combustion engine engine is analyzed. Firstly, the finite element model of the engine components is established, and the dynamic response is calculated in the multi-body dynamics software AVL under different operating conditions. Secondly, the modal analysis of the crankshafts of three different materials is carried out. The natural vibration characteristics of the mechanical structure and the relationship between the modal frequency and the engine speed and order are explored. Finally, the normal integral velocity and the sound power level of the outer surface of the engine are calculated and used as evaluation criteria.