Field an experiment was carried out in the farms of Agriculture and forestry academy at University in Nineveh. The research was conducted to investigate a practical study for the effect of four forward speeds (1.9, 2....Field an experiment was carried out in the farms of Agriculture and forestry academy at University in Nineveh. The research was conducted to investigate a practical study for the effect of four forward speeds (1.9, 2.6, 3.8 and 4.7 km/hr.) and three acceleration direction of axes lateral, longitudinal and vertical, and two types machines control (Mower and Rotovators) on the vibrations transferred to the steering wheel horticulture tractor type (Goldoni). The vibration points on the handgrip were calculated and tested. Root mean square acceleration (RMS), given in m/sec2, was calculated. Results showed increased acceleration vibration of the three directions (longitudinal, lateral and vertical) transferred to the steering wheel tractor by increased forward speed. The Mower score recorded the highest acceleration vibration for the three directions of Rotovators. The levels of vibration emitted from tractor to hand an operator during the experiment was high comparing with standard mechanical vibration. Handgrip vibration intensity in the vertical direction is bigger than the lateral and longitudinal direction. The total vibration evaluating was denoted as the square root mean of the three sum value (lateral, longitudinal and vertical) directions. The paper purpose was measuring and analyzing vibration level transferred to the steering wheel and reduces the machine vibration. This paper is helpful for design in order to increase the develop safety systems in easy and economical way.展开更多
Tractor as one of the most widely used agricultural machinery should be considered from different aspects.The frequent application of clutch and brake pedals and also the steering wheel within farms,along with the unf...Tractor as one of the most widely used agricultural machinery should be considered from different aspects.The frequent application of clutch and brake pedals and also the steering wheel within farms,along with the unfavorable working conditions,cause negative effects on the occupational health of the tractor drivers.Thus,in this research,the imposed forces on three engaged muscles including:Gastrocnemius,Trapezius and Quadrate’s lumborum of the tractor drivers during clutching have been studied.In this regard,algometer device was used to determine the applied forces on selective muscles of drivers during clutching of MF285 and MF399 tractors.The experiments were performed employing sample of 30 drivers and were conducted on two Iranian frequently used tractors including:MF285 and MF399 models.The results showed that the clutching forces for MF285 and MF399 tractors were 340 N and 290 N,respectively.The knee angle of the drivers of the two tractors was statistically different at the one percent level of significance.The reduction of pain threshold after 30 and 60 s clutching and also 60 s rest after clutching in MF285 tractor,for all three muscles,were more than those of MF399 tractor.The impact of clutching on the average decreases of pain threshold,for all drivers and all clutching periods,during and after clutching,in the Quadratus lumborum muscle was more than the other two muscles,in both tractors.In order to reduce the clutching force for MF285 tractor some modifications is suggested.In this regard the force transfer joint between the pedal and the clutch release linkage may be replaced with one made of cast iron.展开更多
文摘Field an experiment was carried out in the farms of Agriculture and forestry academy at University in Nineveh. The research was conducted to investigate a practical study for the effect of four forward speeds (1.9, 2.6, 3.8 and 4.7 km/hr.) and three acceleration direction of axes lateral, longitudinal and vertical, and two types machines control (Mower and Rotovators) on the vibrations transferred to the steering wheel horticulture tractor type (Goldoni). The vibration points on the handgrip were calculated and tested. Root mean square acceleration (RMS), given in m/sec2, was calculated. Results showed increased acceleration vibration of the three directions (longitudinal, lateral and vertical) transferred to the steering wheel tractor by increased forward speed. The Mower score recorded the highest acceleration vibration for the three directions of Rotovators. The levels of vibration emitted from tractor to hand an operator during the experiment was high comparing with standard mechanical vibration. Handgrip vibration intensity in the vertical direction is bigger than the lateral and longitudinal direction. The total vibration evaluating was denoted as the square root mean of the three sum value (lateral, longitudinal and vertical) directions. The paper purpose was measuring and analyzing vibration level transferred to the steering wheel and reduces the machine vibration. This paper is helpful for design in order to increase the develop safety systems in easy and economical way.
基金The financial support provided by the Ferdowsi University of Mashhah,Iran,is greatly acknowledged.
文摘Tractor as one of the most widely used agricultural machinery should be considered from different aspects.The frequent application of clutch and brake pedals and also the steering wheel within farms,along with the unfavorable working conditions,cause negative effects on the occupational health of the tractor drivers.Thus,in this research,the imposed forces on three engaged muscles including:Gastrocnemius,Trapezius and Quadrate’s lumborum of the tractor drivers during clutching have been studied.In this regard,algometer device was used to determine the applied forces on selective muscles of drivers during clutching of MF285 and MF399 tractors.The experiments were performed employing sample of 30 drivers and were conducted on two Iranian frequently used tractors including:MF285 and MF399 models.The results showed that the clutching forces for MF285 and MF399 tractors were 340 N and 290 N,respectively.The knee angle of the drivers of the two tractors was statistically different at the one percent level of significance.The reduction of pain threshold after 30 and 60 s clutching and also 60 s rest after clutching in MF285 tractor,for all three muscles,were more than those of MF399 tractor.The impact of clutching on the average decreases of pain threshold,for all drivers and all clutching periods,during and after clutching,in the Quadratus lumborum muscle was more than the other two muscles,in both tractors.In order to reduce the clutching force for MF285 tractor some modifications is suggested.In this regard the force transfer joint between the pedal and the clutch release linkage may be replaced with one made of cast iron.