商用车通过噪声优化研究

Research on Optimization of Noise Emitted by Commercial Vehicle

某纯电重卡根据GB 1495-2002《汽车加速行驶车外噪声限值及测量方法》进行测试时,发现动力模式(P模式)下,50km/h进线时,车外噪声测试结果为84.9dB(A),不满足限值(≤84 dB(A)),根据主观感受结果和频谱图滤波回放,确认问题发生频率在2500Hz左右,跟踪电机转速发现电机的2.2阶能量贡献明显,并结合电机参数和内部传动结构特性,计算对应阶次零部件为轮边减速器,通过吸音棉包裹、更换新样件等方案验证,最终发现轮边减速器齿轮精度和轮边减速器啮合激励与端盖模态耦合共振,导致噪声增大,通过提高端盖模态和提高轮边减速器齿轮精度,问题得到优化。

When a pure electric heavy-duty truck was tested according to GB 1495-2002"Limits and Measurement Methods for External Noise of Automobile Acceleration Driving",it was found that in power mode(P mode),when entering the line at 50km/h,the external noise test result was 84.9dB(A),which was below the limit value(≤84 dB(A)).Based on subjective perception results and frequency spectrum filtering playback,it was confirmed that the frequency of the problem was around 2500Hz.Tracking the motor speed revealed that the 19.71st order energy contribution of the motor was significant,Combined with the motor parameters and internal transmission structure characteristics,the corresponding order component was calculated as the wheel reducer.Through schemes such as wrapping with sound-absorbing cotton and replacing new samples,it was finally found that the coupling resonance between the meshing excitation of the wheel reducer gear and the end cover mode led to an increase in noise.By optimizing the end cover mode and improving the accuracy of the wheel reducer gear,the problem was optimized.