チェインソーの評価法 (I) : 振動について (1)

Abstract

チェインソーの普遍的評価法を確立するために, そのうちの振動について評価法を検討した。今回は人間に及ぼす影響を心拍数, 皮膚温について実験した。・心拍数は周波数の増加により減少する傾向があった。被験者の違いにより共振周波数が異なると思える結果が心拍数に現われた。・皮膚温の低下は63Hzと4, 000Hzで観察された。・心拍数は実験手法が不十分であり, 更なる検討が必要であるが, 皮膚温は評価法として使えそうである。・今後は, より大きい振動力による実験を行なって, 心拍数・皮膚温との関係をはっきり調べる必要がある。

In Japan, many operators of chainsaw suffered from vibration hazards, especially from "White Wax disease". Thus, the development of effective vibration-isolation systems is desired eagerly for the health of worker. Then, we experimented whether the heart rate and the skin temperature of the finger are useful as an index to display the effects of vibration to the human body. For the heart rate tests, the acceleration of the input force at the hand by using electrodynamic shaker was held constant at 3g* (peak) while the frequency of the force was varied from 16 Hz to 2000 Hz, and for the skin temperature tests of finger, the acceleration of the input force at the middle finger was held constant at 3g (peak) while the frequency of the force was varied from 0 Hz to 8000 Hz (Fig. 2, 3) The following became clear after we examined the results. The heart rate had a slight tendency towards inferiority while the frequency increased. The skin temperature of the middle finger dropped at 63Hz and 4000Hz. After this, it is desirable to repeat repeat many tests in detail about the skin temperature of the finger, and to improve the method of the heart rate test. * (1g=980cm/sec2)