Abstract: The mechanism and control methods of vibration of the steering wheel at idle are analyzed. Study is focused on the transmission path of the half shaft universal joint and the main influencing factors of natural frequency of the steering system. Aiming at the problem of overly large vibration of the steering wheel at idle condition for an AT vehicle when the air conditioner is switched on, the excitation source, the main transfer path and the steering system modals are analyzed. The main cause of the huge vibration is found to be the extremely large force from the half shaft and the coupling effect of the steering wheel natural frequency and the engine excitation frequency. Through reducing the idle target speed of the engine by 50rpm, changing the drive shaft universal joint from DO-type to GI-type and strengthening the steering column structure, the transfer force of the half shaft is reduced significantly and the natural frequency of the steering system is increased, so that the idle vibration of the steering wheel is controlled effectively.

Key words: vibration and wave, steering wheel, idle vibration, universal joint, steering system

摘要： 在分析汽车怠速工况下方向盘振动产生机理基础上，针对某款AT轿车怠速开空调时方向盘振动过大的问题，分别对激励源、主要传递路径及转向系统模态进行分析。得出驱动轴传递力偏大及方向盘固有频率与发动机激励频率耦合是导致该车怠速工况方向盘振动大的主要原因。在此基础上，提出并实施发动机怠速目标转速降低50 r/min、驱动轴万向节节型由DO型改为GI型及转向柱结构加强三个方案，有效降低驱动轴传递力及提高转向系统固有频率，使该车方向盘怠速振动得到有效控制。

关键词: 振动与波, 方向盘, 怠速振动, 万向节, 转向系统