Raios de curvatura, larguras de bitola e comprimentos do cabeçalho influenciam na qualidade do paralelismo?
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Data
2020-02-28
Autores
Nicolau, Francisca Edcarla de Araujo
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
As propriedades que atuam no deslizamento lateral de um equipamento de arrasto em áreas agrícolas, variam amplamente, indo desde as relacionadas ao solo até aos parâmetros envolvidos no sistema trator-equipamento que podem afetar o deslocamento lateral. O objetivo com o estudo foi mensurar o erro de paralelismo do conjunto trator-protótipo em função de diferentes raios de curvatura, larguras de bitola e comprimentos do cabeçalho de um protótipo de arrasto, além de avaliar a variabilidade do processo por meio do Controle Estatístico do Processo. Os testes foram realizados em área experimental da Universidade Estadual Paulista (Unesp), Faculdade de Ciências Agrárias e Veterinárias, Câmpus de Jaboticabal. Foi adaptado o chassi de uma semeadora-adubadora, que possibilitasse mudança no comprimento do cabeçalho e variação na largura da bitola do equipamento, o qual denominamos protótipo de arrasto. O delineamento experimental foi o inteiramente casualizado, em esquema fatorial 5x4x15, com cinco comprimentos do cabeçalho e quatro larguras de bitola do protótipo em quinze raios de curvatura médio. A medição do paralelismo entre as passadas do conjunto trator-protótipo foi obtida por meio de um instrumento desenvolvido que denominamos “pirulito” e com o auxílio de uma trena. Nos raios de 16,4 m e de 20 m os erros de paralelismo são maiores, em todas as bitolas e vão diminuindo à medida que se aumenta a circunferência do raio. O comprimento do cabeçalho de 2,40 m, quando comparado com os demais obteve menor erro de paralelismo nos três primeiros raios. Nos dois primeiros raios quase todos os erros de paralelismo ficaram fora dos limites específicos de controle para todas as larguras de bitola e comprimentos do cabeçalho. A menor bitola do protótipo, e o menor cabeçalho proporcionaram menores erros de paralelismo entre as passadas do conjunto trator-protótipo. Nos trajetos com maiores raios de curvatura e menores comprimentos do cabeçalho, associados com a menor bitola do protótipo, proporcionam melhor qualidade nos processos mecanizados, sem causar sobreposição ou falha.
The properties that act on the lateral sliding of a trailed equipment in agricultural areas, change widely, ranging from those related to the soil to the parameters involved in the tractor-equipment system that can affect lateral displacement. The objective of the study was to measure the parallelism error of the tractor-prototype set as a function of different curvature radius, the widths of the gauge and the lengths of the header of a drag prototype, in addition, the evaluating process of the variability through the Statistical Process Control. The tests were carried out in an experimental area at the São Paulo State University (Unesp), School of Agricultural and Veterinary Sciences, Campus of Jaboticabal. The chassis of a seeder-fertilizer was adopted, so that it would allow a change in the length of the header and a variation in the width of the gauge of the equipment, which we call the trailed prototype. The experimental design was entirely randomized, in a 5x4x15 factorial scheme, with five header lengths and four widths of gauge of the prototype in fifteen average curvature radius. The measurement of the parallelism between the steps of the tractor-prototype set was obtained by using an instrument that we call “lollipop” and with the help of a measuring tape. In the 16.4 m and 20 m radius the parallelism errors were greater than the other gauges, and it decreased as the radius circumference increased. The header length of 2.40 m, when compared to the others, obtained the smallest error of parallelism in the first three radius. In the first two radius almost all parallelism errors were outside the specific limit control for all widths of the gauge and the lengths of the header. The smallest gauge of the prototype, and the smallest header that provided smallest errors of parallelism between the steps of the tractor-prototype set. On paths with greater radius of curvature and shorter lengths of the header, associated with the smaller gauge of prototype, provide better quality in mechanized processes, without causing overlap neither failure.
The properties that act on the lateral sliding of a trailed equipment in agricultural areas, change widely, ranging from those related to the soil to the parameters involved in the tractor-equipment system that can affect lateral displacement. The objective of the study was to measure the parallelism error of the tractor-prototype set as a function of different curvature radius, the widths of the gauge and the lengths of the header of a drag prototype, in addition, the evaluating process of the variability through the Statistical Process Control. The tests were carried out in an experimental area at the São Paulo State University (Unesp), School of Agricultural and Veterinary Sciences, Campus of Jaboticabal. The chassis of a seeder-fertilizer was adopted, so that it would allow a change in the length of the header and a variation in the width of the gauge of the equipment, which we call the trailed prototype. The experimental design was entirely randomized, in a 5x4x15 factorial scheme, with five header lengths and four widths of gauge of the prototype in fifteen average curvature radius. The measurement of the parallelism between the steps of the tractor-prototype set was obtained by using an instrument that we call “lollipop” and with the help of a measuring tape. In the 16.4 m and 20 m radius the parallelism errors were greater than the other gauges, and it decreased as the radius circumference increased. The header length of 2.40 m, when compared to the others, obtained the smallest error of parallelism in the first three radius. In the first two radius almost all parallelism errors were outside the specific limit control for all widths of the gauge and the lengths of the header. The smallest gauge of the prototype, and the smallest header that provided smallest errors of parallelism between the steps of the tractor-prototype set. On paths with greater radius of curvature and shorter lengths of the header, associated with the smaller gauge of prototype, provide better quality in mechanized processes, without causing overlap neither failure.
Descrição
Palavras-chave
Controle Estatístico de Qualidade, Controle Estatístico do Processo, Deslocamento lateral, Equipamento de arrasto, GNSS, RTK, Agricultura de precisão, Máquinas agrícolas, Máquinas automáticas, Statistical Quality Control, Statistical Process Control, Lateral displacement, Trailed equipment