Experimental Study on Vibration and Noise of Minibus Rear Driving Axle

Test of interior and external noise and vibration signals of Minibus were conducted in accelerating and constantvelocity driving conditions. By using time domain, frequency domain and 3D spectral arraymethods, the exterior noise, interior noise, the vibration acceleration of driver's seat and driving axle, the NVH characteristics of the Minibus were analyzed. On the one hand, we find that theinterior noise is larger than exterior noise under accelerating state, due to the cabin poorly sealing. On the other hand, because of the poor isolation rate of the suspension and the huge noise and vibration of driving axle and power train, the interior noise is very great and affecting the driver's comfort. The experimental results shows that the main frequency components of interior noise consist of two parts, one is the low frequency which origins from vibration exciting of the power train, and the other is the middle and high frequencies which origin from vibration exciting of the driving axle and transmission system. Theseexperimental results will give help to further study of the NVH characteristic of the Minibus.