Abstract: During the road tests of a certain pure electric multi-purpose vehicle (MPV) model in the research and development stage, the vehicle emittes a distinct 480 Hz beeping "whooshing" sound under acceleration, coasting and constant speed operating conditions, indicating poor sound quality inside the vehicle. Through spectral analysis, it is confirmed that there is a distinct resonant band in the 480 Hz frequency band for the noise inside the vehicle under all three operating conditions. Through filtering and playback, it is determined that this resonance band is the fundamental cause of leading to the "whooshing" sound. Through investigation, the issue is traced to the excitation of the drive motor's constrained mode resonance during vehicle operation. Ultimately, by optimizing the installation structure of the drive motor, on the one hand, the rigidity of the installation bracket is enhanced, and on the other hand, the original two-point installation method is improved to threepoint installation and fixation to solve the noise problem. After optimization, the constrained mode frequency of the drive motor increases from 480 Hz to 580 Hz, significantly improving the inside the vehicle "whooshing" noise and meeting the design target requirements.

Key words: resonance noise; acoustic quality; resonance band; filtering playback; modal analysis

摘要： 某纯电动多用途汽车（MPV）车型在研发阶段进行道路测试时，车辆在加速、滑行及 匀速工况下均出现明显的 480 Hz 蜂鸣“呜呜”声，车内声品质较差。通过频谱分析确认三种 工况下车内噪声均在 480 Hz 频段存在明显共振带，通过滤波回放确定该共振带是导致“呜呜” 声的根本原因。经排查，锁定问题源为在车辆行驶时驱动电机约束模态被激起共振，最终通 过优化驱动电机的安装结构，一方面加强安装支架的刚度，另一方面将原有的两点安装方式 改进为三点安装固定解决噪声问题。优化后驱动电机的约束模态频率由 480 Hz提升至 580 Hz， 车内“呜呜”声改善明显，满足设计目标要求。

关键词: 共振噪声；声品质；共振带；滤波回放；模态分析