Hearing injury due to exposure to excessive noise during general farming activities is a significant problem for farmers.The present investigation was carried out for better understanding of the noise propagation tren...Hearing injury due to exposure to excessive noise during general farming activities is a significant problem for farmers.The present investigation was carried out for better understanding of the noise propagation trends,as well as noise attenuation characteristics of the two different developed power tillers on different surfaces in transportation under Egyptian conditions.In Egypt,the agricultural roads are one of the main problems that limited the usage of farm machinery.In the last few years,it is noticed that the manufacturers and farmers in Egypt applied the diesel engine of command irrigation pump as the source of power for the manufactured power tillers.Besides their on-farm application in Egypt,they are also engaged in transportation of agricultural products and human beings on the asphalt,and dirt rural roads.In spite of their adverse effects due to noise on operators and bystanders,limited information is available concerning the noise investigation of these manufactured machines.The aim of this research was to evaluate the noise propagation trends as well as noise attenuation characteristics of the manufactured power tillers on different surfaces in transportation conditions.The developed power tillers that used in this study were fitted with approximately 6 kW(8 hp)and 7.5 kW(10 hp)diesel engines for two different tillers transport machines.During measurement and recording the sound pressure signals of the power tillers,the variables of engine speeds and gear ratios were varied to cover the most normal range of the power tillers operation in transportation conditions for the asphalt and dirt rural roads.The test sites were prepared according to SAE noise measurement test procedures.The maximum overall noise measured at driver ear’s position at different gear ratios in asphalt,and dirt rural roads were about 98.2 and 92 dB(A)for 1,350 r/min engine speed which is higher than allowable noise exposure prescribed by National Institute for Occupational Safety and Health[1].展开更多
文摘Hearing injury due to exposure to excessive noise during general farming activities is a significant problem for farmers.The present investigation was carried out for better understanding of the noise propagation trends,as well as noise attenuation characteristics of the two different developed power tillers on different surfaces in transportation under Egyptian conditions.In Egypt,the agricultural roads are one of the main problems that limited the usage of farm machinery.In the last few years,it is noticed that the manufacturers and farmers in Egypt applied the diesel engine of command irrigation pump as the source of power for the manufactured power tillers.Besides their on-farm application in Egypt,they are also engaged in transportation of agricultural products and human beings on the asphalt,and dirt rural roads.In spite of their adverse effects due to noise on operators and bystanders,limited information is available concerning the noise investigation of these manufactured machines.The aim of this research was to evaluate the noise propagation trends as well as noise attenuation characteristics of the manufactured power tillers on different surfaces in transportation conditions.The developed power tillers that used in this study were fitted with approximately 6 kW(8 hp)and 7.5 kW(10 hp)diesel engines for two different tillers transport machines.During measurement and recording the sound pressure signals of the power tillers,the variables of engine speeds and gear ratios were varied to cover the most normal range of the power tillers operation in transportation conditions for the asphalt and dirt rural roads.The test sites were prepared according to SAE noise measurement test procedures.The maximum overall noise measured at driver ear’s position at different gear ratios in asphalt,and dirt rural roads were about 98.2 and 92 dB(A)for 1,350 r/min engine speed which is higher than allowable noise exposure prescribed by National Institute for Occupational Safety and Health[1].