多点接触模型的盘式制动器制动抖动分析

Analysis of Disc Brake Judder Using Multipoint Contact Dynamic Model

为了探索制动抖动产生机理,预测制动抖动现象,针对盘式制动器系统建立了盘式制动器8自由度多点接触动力学模型。模型中考虑了内外侧制动块、活塞、制动钳以及相互间的接触作用,且制动副摩擦系数-相对速度特性采用半经验试验模型。基于此模型,以实测的制动盘厚薄差为输入,利用Matlab-Simulink软件计算制动转速、制动力矩波动、制动压力波动以及制动钳振动加速度的响应。通过将多点接触模型仿真结果、单点接触模型仿真结果与台架试验结果的时频特性对比分析发现,多点接触模型比单点接触模型在制动抖动预测上具有较高的准确性,在振动加速度的预测方面尤其明显。

In order to explore the brake judder cause and to predict brake judder phenomenon,an eight-degree-of-freedom multipoint contact model of disc brake system is established,in which the inboard pad,outboard pad,wheel cylinder piston and caliper,and the interactions among them are taken into account.In this model,the friction-velocity characteristic of the disc-pad couple is a semi-empirical model.Based on the established model,the brake speed,the brake pressure variation,the brake torque variation and the brake caliper vibration acceleration are calculated in the Matlab-Simulink software,by using the measured disc thickness variation as the model input.The time-frequency characteristics of brake pressure variation,brake torque variation and caliper acceleration,gained from multipoint contact model simulation results,single-point contact model simulation results and the dynamometer test results,are numerically compared.The results show that the multipoint contact model can predict brake judder with higher accuracy than single-point contact model,especially for caliper vibration simulation.