No abstract

The objective of this research was to develop concepts, possibilities of occurrence, and ways to solve the vibratory phenomenon of power hop, which is quite common in tractors with auxiliary front-wheel drive or all-wheel drive, in particular conditions of field work. First, the phenomenon is defined, and context is given for the practical situations in which the phenomenon can occur. Subsequently, actions are proposed to solve and minimize the problems arising from power hop. The subject of this study has been insufficiently analyzed in the literature, with mentions (some detailed) in scientific articles and theses developed to diagnose and propose ways to solve the problem. Equally, there has been almost no mention of the problem in agricultural tractor operation manuals, despite the frequent occurrence of the phenomenon.

The use of side brushcutters exposes users to vibration and noise, which can cause damage to the operator, as they act as a stressor agent. Excessive vibration is responsible for countless disorders, including Raynaud’s syndrome. This study aimed to assess the effect of the vibrations of a side brush cutter on the human body. A side brush cutter was used with three cutting implements (double blade, triple blade and double nylon thread) applied to two crops (wheat and ryegrass). The vibration was measured through a three-dimensional accelerometer placed on the handgrips of the brush cutter, in compliance with the provisions of the ISO 5349-1 Standard. The analyzed variables were submitted to the Shapiro-Wilk and Bartlett tests. Due to the abnormality, the data were transformed by the Neperian logarithm and submitted to analysis of variance, and the means were compared by the Tukey test at 5% probability. As a result, the orthogonal y-axis presented a higher vibration level; the three-point blade showed the lowest vibration level compared to the other cutting implements for both crops; these vibration levels did not exceed the NHO10 recommendation. Hence, using the appropriate attachment for each operation may reduce the harm caused by vibration to the operator’s body.

DEMANDA ENERGÉTICA NA SEMEADURA DA SOJA COM DIFERENTES CONFIGURAÇÕES DE SULCADORES   MARCELO SILVEIRA DE FARIAS1, JOSÉ FERNANDO SCHLOSSER2, LEONARDO CASALI2, MATEUS CASSOL CELLA3, ALFRAN TELLECHEA MARTINI4   1 Departamento de Ciências Agronômicas e Ambientais, Universidade Federal de Santa Maria, Campus de Frederico Westphalen, Linha 7 de Setembro, s/n, BR 386, km 40, CEP 98400-000, Frederico Westphalen, Rio Grande do Sul, Brasil, silveira_farias@hotmail.com. 2 Departamento de Engenharia Rural, Universidade Federal de Santa Maria, Avenida Roraima n°1000, Bairro Camobi, CEP 97105-900, Santa Maria, Rio Grande do Sul, Brasil, josefernandoschlosser@gmail.com; leonardo.casali@yahoo.com.br. 3 Departamento de Engenharia Mecânica, Universidade Federal de Santa Maria, Avenida Roraima n°1000, Bairro Camobi, CEP 97105-900, Santa Maria, Rio Grande do Sul, Brasil, mateus996@gmail.com. 4 Coordenadoria Acadêmica, Universidade Federal de Santa Maria, Campus de Cachoeira do Sul, Rua Ernesto Barros, n° 1345, Bairro Santo Antônio, CEP 96506-310, Cachoeira do Sul, Rio Grande do Sul, Brasil, alfrantm@gmail.com.   RESUMO: O objetivo deste trabalho foi avaliar a demanda energética requerida por uma semeadora-adubadora para plantio direto, com diferentes configurações de sulcadores na implantação da cultura da soja, em áreas de várzea. O experimento foi conduzido em duas áreas agrícolas, tipicamente cultivadas com arroz irrigado, localizadas na região Central do estado do Rio Grande do Sul. Utilizou-se o delineamento de blocos aleatorizados, em arranjo bifatorial, sendo avaliadas quatro configurações de sulcadores (haste sulcadora, haste sulcadora com sistema tapa-sulco, disco ondulado e disco duplo), em duas áreas de características distintas (área agrícola 1 e área agrícola 2). As variáveis estudadas foram: força na barra de tração, velocidade real de trabalho, patinamento das rodas motrizes do trator e consumo específico de combustível. Com base nas análises dos resultados obtidos neste estudo pode-se afirmar que, os mecanismos sulcadores influenciam na demanda energética do conjunto mecanizado, independentemente da área agrícola. O consumo específico de combustível com o uso de hastes sulcadoras quando comparado aos discos foi 0,7 vezes menor, para ambas as áreas.   Palavras-chave: mecanização agrícola, força de tração, consumo de combustível, eficiência.   ENERGY DEMAND OF IN SOYBEAN SOWING WITH DIFFERENT FURROWER CONFIGURATIONS   ABSTRACT: This research aimed to evaluate the energy demand required by a seeder-fertilizer for direct planting, with different configurations of furrowers in the implantation of soybean culture, in lowland areas. The experiment was conducted in two agricultural areas, typically cultivated with irrigated rice, located in the central region of the state of Rio Grande do Sul. A randomized block design was used, in a bifactorial arrangement, and four furrow configurations (shank, shank with furrow-groove system, corrugated disc and double disc) were evaluated in two areas with different characteristics (agricultural area 1 and agricultural area 2). The variables studied were drawbar pull, real travel speed, the slippage of the driving wheels of the tractor and specific fuel consumption. Based on the analysis of the results obtained in this study, it can be said that the furrow mechanisms influence the energy demand of the mechanized set, regardless of the agricultural area. Specific fuel consumption with the use of shanks instead of disks was 0.7 times lower, for both areas.   Keywords: Agricultural mechanization, drawbar pull, fuel consumption, efficiency