鼓式制动器低频振动的模型研究

摘要

为研究汽车制动过程中鼓式制动器的低频振动,建立了系统非线性数学模型,基于对制动蹄的惯性力的考虑,推导了鼓式制动器五自由度数学模型,对汽车制动器进行了力学分析和系统稳定性分析,并利用数值分析软件Matlab得出汽车制动器的摩擦系数和特征值、频率的关系.结果表明:制动蹄的惯性力对法向合力的位置没有影响,压力中心的位置只与制动器的结构参数有关.即使考虑恒定的摩擦系数,鼓式制动器的失稳现象也可能发生.失稳时的频率在低频振动的频率范围内,在一定程度上验证了模型的正确性.%To study the low-frequency pibration of drum brake of automobile in the course of applying brake,a non-linear equation of 5-degree of freedom is established,considering the inertia force of brake shoe.By the force analysis of drum brake model and stability of the system, and making use of the numerical analysis software MATLAB, the relationship of automobile brake friction coefficient, eigenvalue and the frequency is achieved.The result shows that the inertia force of brake shoe has no influence on the location of pressure and the location of pressure is determined only by the parameters of brake.What's more, the vibration and instability can occur even when the friction coefficient is constant.The result is in the range of frequency of vibration,and this validates the rightness of the model to some extent.