基于解决变速箱怠速敲齿的摩擦离合器传动系统的建模与分析方法

Modeling and Analysis Method of Automotive Driveline Transmission System for Reducing Gear Rattle

建立汽车怠速状态下传动系统的四自由度集总参数模型,给出怠速工况下系统动态响应的计算方法。定义齿轮敲击指数作为怠速敲齿的评价指标,分析离合器从动盘扭转减振器的多级扭转非线性特性、齿轮间啮合力时变特性对齿轮敲击指数的影响。针对一汽车怠速时敲齿的问题,利用建立的模型,对扭转减振器的一级扭转刚度和一级扭转角进行改进,分析离合器改进前后变速器的齿轮敲击指数、齿轮啮合力以及啮合齿轮间相对位移随时间的变化。在怠速工况下,测试分析离合器改进前后对发动机舱变速器侧的噪声、变速箱壳体振动加速度的影响。测试结果和计算结果表明:齿轮敲击指数与变速器侧的噪声、变速箱壳体振动加速度有一定的关联性;基于本文的建模分析方法,可调整离合器的扭转减振器一级扭转刚度和一级扭转角,降低汽车怠速时变速器的敲齿现象。

A nonlinear torsional model with 4 degrees of freedom for automotive driveline transmission systems at idle is presented and method for calculating dynamic response of the model is proposed. A rattle index is defined for evaluating rattle of a meshed gear pair. For trouble shouting of gear rattle of a car at idle, the influence of nonlinear stiffness and damping of the clutch on rattle index of the car is investigated using the developed model and calculation method. Stiffness and angle limits of the first stage damper of a clutch are improved for reducing gear rattle of a car based on the calculated results of rattle index, meshing force and meshing displacement of the meshed gear pair in the gearbox at idle. Noise at the engine compartment and vibration at one point at the transmission are measured for the baseline clutch and the improved clutches of a car. Comparisons of the measured noise and vibration show that there are corrections between rattle index and the noise at engine compartment and vibration at one point of transmission. It is also concluded that the stiffness and damping can be improved to reduce gear rattle at idle using the modeling and calculating methods presented.