Investigating a Power tiller Handle and Seat Vibration on Transportation mode
Keywords:Vibration, operator, power tiller, 1/3rd octave, exposure limits, Iran
In this paper, vibration a power tiller vibration was investigated at handle position as well as seat position of a trailer pulled by the power tiller. The experiments were conducted at five levels of engine speed, four levels of transmission gear ratio during transportation, and in three directions. Then the weighted 1/3rd octave spectrum was calculated from the narrow band vibration acceleration signals. The amount of vibration damage on operator's body and allowable exposure limits were calculated based on ISO standards. The results showed that the vibration increased with increasing the engine speed for all the gear ratios and directions. The magnitude of vibration was the greatest at vertical direction in all the experiments. The vibration allowable exposure time was in the range of 2.32-5.7 years at the power tiller handle for the different engine speeds and gear ratios. The total equivalent vibration, A (8), at the trailer seat was in the range of 0.5 to 0.87 m/s2 and it exceeded the allowable limits for the reduced comfort boundary, fatigue-decreased boundary and exposure limit for 8 hours/day. So, it is necessary to reduce the vibration transmitted to the operator’s hand and body by designing and developing adequate insulating systems.