Studies on the Threshold Limit Value of Local Vibration of the Vibrating Agricultural Machinery

Experiment of sinusoidal Motion by the Vibration Exciter

Abstract

The human being in many modern man-machine-system has to endure various stress. As a result of pro gress in the development of vibrating agricultural machinary, more and more has been demanded of the human operator.
The authors tried to determine the threshold limit value of local vibrating agricultural machinery.
The vibration was applied on the hand by electrodynamic sinusoidal exciter with test handle.
Some tests terms for the purpose of investigating the effect of mechanical vibration were skin temperature of hand, pulse rate, surface electromyogram in muscle, and the sense of touch. The results obtained were as follows:
(1) In case of higher vibration, the skin temperature of the back of hand showed a decline, and a rise later during the application of vibration. From this result, the authors tried to determine the limit value of vibration, which is showh in Fig 5, and Fig 6.
(2) The average pulse rate and frequency analysis of surface electramyogram in muscle had little effect.
(3) The results by sense of touch test were almost the same with that by skin temperature test.