Avaliação do ruído e do desempenho energético de um trator de rabiças com um arado de disco acoplado

Abstract

The initial tillage has great importance for agricultural production. This activity is usually performed by animal traction in family farming. In this paper, we studied the use of handlebar tractors as a source for field work optimization. The experiment was conducted with a handlebar tractor with a plow attached to it at the Federal University of Ceará. The goal was to evaluate the energetic efficiency of the handlebar traitor attached to the disc plow, using three gears (1st, 2nd, 3rd) in a red, yellow argisoil. It was also evaluated the soil shoaling and the noise levels with the machine both stopped in different rays of distances (1, 2, 5 and 10 meters), and with handlebar traitor in movement, using three different number of turns (810, 1040 and 1360 rpm). To obtain data about energetic efficiency, it was used a handlebar traitor, an instrument with inductive sensors on wheels to measure the wheelsets slippage, a flowmeter to measure the fuel consumption and a loading cell to obtain the workforce in the drawbar. To install the loading cell and obtain the implement stability, it was necessary to use a train, in which the set traveled 25m with three repetitions in each gear to the collecting of the data. The soil shoaling was calculated through the data obtained in the field by a profilometer, and the levels of noise were measured with a dosimeter and a decibelimeter. The studied variables were the hourly fuel consumption (L.h-1), the specific fuel consumption, (g.kW.h-1), the wheelsets slippage (%), traction force in the bar (kN), work speed (m.s-1) and available power (kW). These data were evaluated with the plow working and with the implement raised to be compared. We calculated the difference (results with the implement plowing minus the results with the plow not working) to study the obtained averages. Data analysis was performed using descriptive statistics using the computer program Assistat 7.6 beta. The results showed that the average rates of slippage were 10% (1st gear), 12 % (2nd gear) and 18% (3rd gear). The average rates for the plow while it was working for the hourly fuel consumption were 5,45 L.h-1 (1st gear), 4,22 L.h-1 (2nd gear) and 2,54 L.h-1 (3rd gear); the specific fuel consumption was 3004,98 g.kW.h-1 (1st gear), 4343,88 g.kW.h-1 (2nd gear) and 5787,91 g.kW.h-1 (3rd gear); the power was 1,54; 0,83 and 0,38 kW for 1st, 2nd and 3rd gear respectively, and the movement speed averages were 0,32 m.s-1 (1st gear), 0,41 m.s-1 (2nd gear) and 0,44 m.s-1 (3rd gear). The average rates for the hourly fuel consumption that were found for the moment when the plow was not working, that is, the implement was raised, were 6,58 L.h-1 (1st gear), 5,98 L.h-1 (2nd gear) and 4,20 L.h-1 (3rd gear); the rates for the specific fuel consumption were 3514,09 g.kW.h-1 (1st gear), 4728,22 g.kW.h-1 (2nd gear) and 5787,91 g.kW.h-1 (3rd gear); the power was 1,54 kW (1st gear), 0,83 kW (2nd gear) and 0,38 kW (3rd gear), and the movement speed averages were 0,27; 0,33 and 0,40 m.s-1 for 1st , 2nd and 3rd gears respectively. The soil shoaling achieved the rates 75 % (2nd gear) and, approximately, 64 % for the 1st and 3rd gears. And the levels of noise that were found by the usage of the dosimeter were 95,7dB(A) (1st gear), 98,2dB(A) (2nd gear) and 98,8 dB(A) (3rd gear). The average levels of noise that were found by the usage of the decibelimeter were 76,71; 77,38 and 80,80 dB(A) for the turns 810, 1.040 e 1.360 rpm respectively. It is advised the use of headphones or the decreasing of the working hours for the operator who is working directly with the tractor handlebars.