This experimental reserch reports on the mechanical vibration of chain saws examined from the standpoint of pysical influence to the worker.
Five kinds of gasoline engine (A・B・C・D) and electric chain saw (E) were driven for the tests and unbonded gage type tranceducers, dynamic strain amplifer and oscilloscope (rapicorder) were used for the measuring apparatuses.
Results of the tests are :
1 ) Reration between f c/s (Frequency) and a mm (Amplitude), and g (Acceleration) of vibrate's directions (X・Y・Z) are shown in Fig. 4 and Table 2. From these results, it is considered that the vibration of x was less than Y and Z, and one of the left handle was not so greater as the right.
2 ) The vibration at the cutting timber (Red-pine) are as follows. (Fig. 5).
X_L a mm → increase f c/s → decrese
Y_L a mm → decrese f c/s → increase
3 ) The vibration at the driving under saw chain stop are shown in Fig. 6. From these results, f c/s was not variable but a mm was much smoller than the results of Fig. 4.
4 ) The vibration decresetd by the rubber belt on the handle was not so greater. (Fig. 7).
5 ) The vibration transmitted to the worker's arm were as follows. (Fig. 9).
Chain Saw's Vibration・・・・100%
Worker's elbow ・・・fall below 25%
Worker's Wist・・・・ 〃 5%