关键词: 共振噪声；声品质；共振带；滤波回放；模态分析

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