基于灵敏度分析的某轻卡方向盘怠速抖动治理研究 Research on Idle Jitter Control of a Light Truck Steering Wheel Based on Sensitivity Analysis

某轻型载货汽车方向盘在怠速工况下抖动严重，利用模态试验分析其怠速抖动原因，发现方向盘模态频率与发动机二阶点火频率接近，引起共振现象。为降低方向盘振动，结合有限元分析方法和灵敏度分析，调整方向盘结构和仪表台横梁管柱的厚度，对转向系统进行结构优化，从而改变方向盘的固有频率，远离发动机的二阶点火频率，减小共振。最后通过试验验证了改进措施的有效性。 The steering wheel of a light truck has a jitter problem in the idle condition. We used modal test to analyze the jitter reason under idle condition. It is found that the modal frequency of the steering wheel is close to the second order ignition frequency of the engine so the resonance of the steering wheel appears. In order to reduce the steering wheel vibration, we combined with the finite element analysis method and sensitivity analysis method. We adjusted the structure of the steering wheel and the thickness of the instrument panel beam to optimize the structure, thereby changing the natural frequency of the steering wheel. Measures works and the natural frequency was far from the second order ignition frequency of the engine. Finally, the effectiveness and rationality of the improvements were verified through tests.