農作業におけるトラクターの振動と騒音

抄録

Vibration and noise of three types of tractors were measured under various conditions of operation from the viewpoint of occupational health. The other hand, daily records of operation time of tractors were collected from 135 households and exposure time to tractor vibration were estimated from these data.
Vibration spectra are showed in Fig. 1 and noise spectra in Fig. 2. The peaks of vibration spectra of tractor's seats are in the high frequency range corresponding to rev count of the engines. However, components of the low frequency range become often hygienic problem, when compared to ISO's Standard 2631-1974 (E) “Guide for the evaluation of human exposure to whole-body vibration.”
Vibration acceleration levels of the tractor operating with various accessories are higher in the low frequency range than those without accessories.
Acceration levels of Y and Z directions are higher than that of X direction and unfavorable hygienically. Antivibration countermeasure should be taken to the Y direction not only to the Z direction.
Noise level of tractors exceed the hearing conservation criteria for daily 8 hour exposure, when they run at high speed. More serious problem is that the noise disturb speech communication between the driver and his co-workers or among co-workers. To prevent labor accidents tractor noise should be controlled.