某四缸发动机振动分析及减振设计研究

Vibration Analysis and Vibration Reduction Design of a Four-Cylinder Engine

汽车的振动噪声一直汽车工程领域研究的热点问题,发动机振动是造成汽车振动的最主要原因之一。针对某四缸发动机设计研发过程中,增加扭矩、提高功率所带来的整机振动问题,本研究从理论上分析了直列四缸发动机振动时各阶次的激励作用特征,并基于多体动力学理论对某四缸发动机进行振动仿真计算,依据整机振动烈度的计算结果,为发动机减振设计提供开发策略。研究发现,直列四缸发动机引起整机振动的最主要阶次为2阶、4阶和6阶,同时考虑轴系局部变形时,需关注单缸激励所引起的0.5阶次;整机刚度虽满足模态计算要求,但左、右后悬置Z向测点振动烈度较大,需进一步增强后悬置支架的支撑刚度,为发动机减振开发提供理论指导和设计依据。

The vehicle vibration and noise are a hot issue in the field of automotive engineering.Engine vibration is one of the main factors leading to vehicle vibration,which is caused by the increasing torque and power in the development process.In this study,the excitation characteristics of each order of vibration of an in-line four-cylinder engine were analyzed theoretically.Then,the multi-dynamics method was adopted to carry out vibration simulation calculation for a certain four-cylinder engine,and the calculated results were analyzed to provide guidance and design basis for the development and design of engine vibration reduction.It is found that the main orders of in-line four-cylinder engine causing the engine vibration are second-order,fourth-order and sixth-order.Considering the local deformation of shafting,the half order by single cylinder excitation need to arouse attention.Although the engine stiffness could meet the needs of modal calculation,measure points of rear suspension in Z axis vibration intensity attained the maximum.Therefore,the support stiffness of the rear suspension bracket needs to be further enhanced.