Abstract: In order to solve the idling interior noise problem of a commercial vehicle, this paper identifies the noise frequency peak that has a significant impact on the idling interior sound quality of the vehicle through the frequency analysis method of the idling vehicle interior noise. Combined with the physical characteristics of the dynamic balance of the fan rotor, the three-point weighting method is used to build the engine electronic fan dynamic balance test bench. Through frequency calculation, it is confirmed that the fan is the direct excitation source of the roaring noise in the idling vehicle of this model. The results of the fan and interior noise test confirmed the correlation between the dynamic balance value and the vehicle interior noise, and formed a complete target definition method for the dynamic balance value of the electronic fan. Finally, by reducing the dynamic balance value of the fan, the noise effect in the vehicle is significantly improved, and it provides a certain reference for the development of noise, vibration, harshness (NVH).

Key words: Vehicle fan dynamic balance; Three point weighting method; Interior noise; NVH

摘要： 为解决某商用车型的怠速车内噪声问题，通过怠速整车测试车内噪声的频率分析方法， 识别了对于该车型怠速车内声品质有显著影响的噪声频率峰值。结合风扇转子动平衡的物理 特点，应用三点加重法搭建发动机电子风扇动平衡测试台架，通过频率计算确认了风扇是该 车型怠速车内噪声存在轰鸣感的直接激励源，并通过不同动平衡值的风扇与车内噪声测试的 结果，确认了动平衡值与整车车内噪声的关联性，形成了完整的电子风扇动平衡值的目标定 义方法。最终，通过降低风扇动平衡值进而显著改善车内噪声效果，并为整车车内噪声、振 动与声振粗糙度（NVH）性能开发提供了一定的参考。

关键词: 车用风扇动平衡；三点加重法；车内噪声；NVH