Engenharia Agrícola - Artigos

URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11739

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Data inicial: 2010Data final: 2017Assunto: search.filters.subject.Instrumentation

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    Dynamic traction of a mechanized set based on technical and operational parameters
    (Engenharia Agrícola, 2017-05) Fernandes, Haroldo C.; Leite, Daniel M.; Teixeira, Mauri M.; Cecon, Paulo R.; Furtado Júnior, Marconi R.
    The objective of this study was to evaluate and model the traction performance parameters of a tractor 4x2 FWD, according to the tractor speed, the internal pressure and the type of tires construction. For each type of tire construction was assembled an experiment in which we evaluated the influence of internal pressures of the front and rear tires and the speed of the mechanical assembly. It was found that the sliding of the diagonal run, presented significant effect in all variables analyzed, since the radial showed no influence of the factors evaluated. The power available in the drawbar was higher when the tractor was equipped for radial tires. The response variables, fuel consumption schedule and specific fuel consumption were more sensitive to the speed of the internal tire pressure. The fuel consumption per area worked, did not affect the analyzed variables. As for the effort prediction models in the tractor drawbar, it was only possible for diagonal run, which are influenced by speed and internal pressure levels of the front and rear tires.
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    Influence of the impact of a rigid rod on the coffee fruits detachment by mechanical vibrations
    (Revista Agrarian, 2016) Gomes, Ely Queiroz; Santos, Fábio Lúcio; Jesus, Valquíria Aparecida Mendes de
    Nowadays, the coffee sector has passed by a transition due the lack of labor, which makes manual harvesting unfeasible. The mechanization has been the solution found by the coffee farmers to overcome the problem of lack of labor and also reduce the production costs. The aim of this study was to evaluate the detachment efficiency behavior of the coffee fruits under mechanical vibrations transmitted to the fruit-stem system by impact of a rigid rod, and mechanical vibrations transmitted to the system without the impact. Trials to evaluate the fruits detachment were performed varying the vibration frequency, the ripening stage of the fruits, the number of fruits at the same stem and the way of transmission of the mechanical vibrations to the fruit-stem system. The detachment efficiency of red fruits was higher than green fruits. It was observed an increase of the detachment efficiency associated to the increase the frequency of vibration. Detachment efficiency obtained from mechanical vibrations transmitted due the impact of a rigid rod on fruit-stem system was 19.4% higher than mechanical vibrations transmitted without impact.