Vibrações em operador de trator agrícola na operação de semeadura sob sistema plantio direto

Abstract

Through the use of machines and equipment, it is hoped to increase the productivity of tillage, aiming at a lower cost, without harming the man and the environment. In this sense, the agricultural tractor is fundamental in the execution of the tasks but operators report pain in the lower back and discomfort at the operating post of some tractors. Thus, the aim of this study was to analyze the vibrations in the body and at the extremities (hands and arms) of an agricultural tractor operator in the seeding operation under no-tillage system. The study was performed in two experiments. The first one in Santa Maria/RS, where it was submitted an Massey Ferguson tractor, model MF 4291, 4x2, with front-wheel-drive assist (FWD) and operation of the kind the seeding operation cabined directly to which was attached a fertilizer seeder Sfil brand, model PSM Hytech 8000.The second experiment was conducted in the city of Carazinho-RS, submitting a Massey Ferguson tractor, model Dyna6, 4 x 2 7415 (FWD) cabined, the same operation, coupling two seeders-drag large together shaped Semeato mark, model SSM 27 no-tillage. In the first experiment, for measuring the magnitude of whole-body vibration and hand and arm Triaxial accelerometers were installed in the seat and steering wheel interface operator-hands and accelerometers at the base of the Bank and UNI axially round out the cabin next to the cushion. In the second experiment was installed a triaxial accelerometer in the seat-operator and a uniaxial accelerometer on the base of the bank. For collection, processing and storage of the data was used a portable Analyzer, 4447 model of Bruel & Kjaer. The experiment in Santa Maria-RS was conducted in Randomized block Design (RBD), with ballasting mixed (and) on the tractor, showing the mass/power relations 77.33 kg.kW-1; 70.59 kg.kW-1; 61.78 kg.kW-1 and and 55 kg.kW-1 rigidity adjustment of seat maximum, minimum and average. The experiment conducted in Carazinho-RS was in RBD with two types of settings in the seeders. As a conclusion to the first experiment, it was verified that the greater intensity of vibration occurred in the direction of the Z axis for most configurations of ballasting. The relation mass/power of 70.59 kg.kW-1 and Medium stiffness of the seat presented better comfort levels for the operator in full body vibrations and the mass / power ratio of 61.78 kg.kW-1 was the one that presented the lowest intensity of vibration in hands and arms, thus, better comfort. For the second experiment was not statistically differ from the parameters of the vibrations of the first embodiment, with the second embodiment in seeders. In the first configuration the seeders the greater vibration intensity occurred in the X-axis direction and in the second configuration the greater vibration intensity has occurred in the direction of the axis Y. Therefore, this study draws attention to the realization of the adjustment of the rigidity of the seats on agricultural tractors by operators in order to improve their working environment.