| Popis: |
The tested wheel loader machinery noise was 110dB and driver position was 108dB, more than Chinese earth-moving machinery standard. Engine noise is the main noise, so thirty-five test points were arranged around the cab and engine to analyze and find the main noise points. The frequency spectrogram show that the main frequency band for the engine and exterior cab are 120Hz and 216Hz, and the interior cab noise was caused by the vibration of the power train passed through the frame result in resonance. Analyzed and calculated the main frequency concludes that the main noise resources are engine exhaust noise and cooling fan noise. To decrease the noise, proper damping materials were affixed to the engine hood and interior cab, the metal pieces were tightened and the cooling fan and shock absorber were replaced with new ones that match the main noise frequency. |
