Exposição humana à vibrações de corpo inteiro em um trator agrícola em operação de semeadura

Abstract

Exposure to high levels of vibration can cause irreversible problems of muscle order, osseous, sensorial, vision, and others. The high work that agricultural operators facing day-by-day and characteristics of agricultural tractors, has increasingly aggravated these problems, also causing a losses in operational efficiency in agriculture. In view of this, this study aimed to evaluate the whole body vibrations incidents in a tractor operator using bias and radial-ply tires, with three different pressures in operation of seeding. The work was divided in Experiment 1 (with three bias tire pressures) and Experiment 2 (three radial-ply tire pressures). The study was conducted in an experimental area located in UFSM, divided into three treatments for each experiment, with four replicates each, totaling 24 experimental units. For this work, was used a tractor Massey Ferguson model 5450, 4x2 with front wheel assist, 75 kW, connected to a planter of the same brand, model 509, 9 lines. The bial tires Pirelli used were TM 12.4-24 95 R1 for the front axle and Goodyear Dyna Torque II 18.4-30 R1 to the rear and Michelin radial-ply were VF 480/60 R28 for the front axle and VF 600/60 R38 for the rear. The pressures used were 96, 138 and 179 kPa for bial tires, and 41, 69 and 96 kPa for radial-ply. The equipment for data acquisition was the 4447 Type of Brüel & Kjær, same brand of software for analysis 4447 Vibration Explorer. For the Average Values of Effective Accelerations (RMS) and Vibration Dose Values (VDV), all treatments showed results that were in the range Extremely Uncomfortable, according to the limits considered by the Standard ISO 2631. However, no statistical difference was found in none of the experiments, when the inflation pressure of the tire has been changed. In both experiments the X axis was presented the greatest values of incidents vibration to the operator. Finally, it was concluded that for a day of 8 hours of work, in both experiments, the operator is exposed above the comfort limit established by the Standard ISO 2631, which is 2.0 m/s².