Ângelo Vieira dos Reis

Performance and constructive characteristics of a pneumatic meter prototype for rice seeds

The increasing cost of seeds for the small grain crops and the inadequacy of the current precision planters, which do not sow crops with small inter roll spacing, this study has the objective of presenting the test results of a prototype vertical drum pneumatic meter for rice seeds. Laboratory tests were conducted to determine the seed metering precision (with pressure range of -56.0; -62.7 and -73.1 kPa, peripheral speeds of 0.10, 0.22 and 0.30 m s-1, and hole diameters of 1.2 and 1.5 mm), seed longitudinal distribution (with seed hoper at 25 and 50% of capacity, lateral inclination of 0 and 11o, and 1.5 mm diameter holes) and mechanical seed injury, in fully randomized experiments. Means of treatments were compared using analysis of variance. The conclusions were that the best results for seed meter were obtained with the lower speed with the lower pressure level, regardless of the hole size. The percentage of singles metering was as high as 68.4%, in average, with the 1.5 mm diameter hole. The seed longitudinal distribution achieved 37.6% of singles times at the end of the seed tube. The level of seeds in hoper and the lateral inclination did not significantly affect the precision. The prototype did not raise the amount of injured seeds.

Análise dos esforços em sulcadores empregados em semeadoras-adubadoras de baixa potência

The furrow openers for no-till system should be easy to penetrate the soil, generate low levels of soil mobilization and require a little traction force. Thus, the aim of this research was to compare six hoe-type furrow openers, four of industrial manufacturing and two handcrafted models, which were used in planters in the region of Pelotas, Brazil. The parameters for comparison among these furrow openers were the horizontal (Fh) and vertical (Fv) forces acting on the tip of the hoe and the cross-sectional area mobilized in the furrow. The experimental design was randomized, with six treatments (furrow openers) from T1 to T6, with four repetitions, constituted by their passage through plots of 20 x 3 m. The force data were collected by load cells and a signal conditioner. The determination of the mobilized area in the furrow was done by a micro soil profilometer. It was concluded that the furrow openers T1, T4 and T6 presented the lowest values of horizontal force (statistically equal and ranging between 1,034 and 1,230 N) and that T1 and T2 produced the highest vertical forces downwards (statistically identical and varying between 749 and 845 N). The furrow openers T1, T2, T4, T5 and T6 generated soil mobilization statistically equal and between 0.006993 and 0.008933 m2.

Development of a device for measuring forces in shanks of no-till planters

Inumeros problemas relativos a mecanizacao dizem respeito aos esforcos demandados pelas maquinas e implementos agricolas. A medicao dos esforcos em implementos de hastes e geralmente feita por instrumentos complexos e de dificil construcao, como os aneis octogonais. Sendo assim, o objetivo deste artigo e apresentar o desenvolvimento de um dispositivo de medicao de esforcos horizontais e verticais em hastes sulcadoras de semeadoras-adubadoras de plantio direto, utilizando transdutores de forca extensiometricos do tipo viga em balanco, comercialmente disponiveis. Para tanto, projetou-se um dispositivo tipo portico, composto de dois transdutores para medicao de esforcos horizontais e um transdutor para medicao do esforco vertical. Os tres transdutores foram montados de modo a restringir qualquer movimento da haste durante a interacao com o solo. O prototipo construido foi submetido a ensaios estaticos em bancada de laboratorio. Em um dos ensaios, aplicou-se carga horizontal na haste; no outro, aplicou-se carga vertical e no terceiro, a carga foi aplicada com inclinacao de 15o em relacao a horizontal, para simular as condicoes de operacao da haste no campo. O dispositivo mostrou-se robusto e, durante os testes de bancada, foi capaz de medir esforcos horizontais de ate 5.300 N, e esforcos verticais de ate 2.000 N, de forma linear e com grande coeficiente de correlacao com as cargas aplicadas.

Validação de um modelo de cálculo por elementos finitos do chassi de uma semeadora de quatro linhas

The static structural behavior of an four row planter experimental frame for family farming was tested using the Finite Element Analysis numerical technique, which took into account the efforts that this machine would be subjected, when suspended over the ground by the three-point hitch of the tractor. To validate the implemented model by SolidWorks Simulation, a real scale prototype was submitted to vertical loads to compare the actual structural displacement to the software calculated displacement. Two studies were made from the calculation model of structural displacement; in the first, it was not included the three- point hitch brackets for calculation, and the measured displacements were not comparable to the calculated ones. In the second study, when hitches were included in the calculation, the results were comparable to those obtained in practice. Therefore, it was concluded that the second study is valid and the frame structure calculations performed by the software are reliable.

DISTRIBUIÇÃO LONGITUDINAL DE SEMENTES DE FEIJÃO (Phaseolus vulgaris L.) COM DOSADOR DE DISCO HORIZONTAL OPERANDO COM UMA OU DUAS SAÍDAS DE SEMENTES

This study aimed to evaluate the effect of horizontal plate meter with oblong holes operating with one or two seed outlets at different speeds over the accuracy of longitudinal distribution of common bean seeds (Phaseolus vulgaris L.). The experiment was performed in laboratory using the meter with one and two seed outlet points in relation to ten tangential disk plate speeds (0.03 to 0.30 m s-1). It was used a complete randomized design with four replications, summing up 80 experimental treatments. Tangential speed quantitative factor was estimated through a 2nd order polynomial regression. There was no significant difference in the behavior of the seed meter operating with one or two outlets in the metering of bean seeds in all tested speeds, with percentage of single seeds spacing over 60% in tangential speeds below of 0.24 m s-1.

Distribuição longitudinal de sementes de milho com dosador de disco horizontal operando com uma ou duas saídas de sementes

This study had the objective of comparing the effect of using the disk plate seed meter with circular holes operating with one or two seed ejection points in relation to the longitudinal precision of the maize seeds distribution. For the evaluation of this effect, the meter was tested in laboratory with one and two seed exits in ten peripheral disk plate speeds (0.03 to 0.30m s-1). It was employed a complete randomized design with four replications, summing up 80 experimental plots. The peripheral speed quantitative factor was estimated through a 2nd order polynomial regression. The behavior of the seed meter operating with one or two ejection points was similar, with significant difference only in peripherical speeds of 0.06 and 0.09m s-1.

Precision mechanical seed meter for small seeds: Functional tests

With current technology there is a limit to the minimum amount of small seeds (wheat, rice, oats, rape seed) that can be distributed in an area which is an obstacle in reducing production costs. Therefore, the development of precision seed meters for small grain crops has already begun. This paper presents the results obtained during the tests of the prototype of a seed meter consisting of a vertical double-face mechanical cylinder, concerning its functional performance in metering and placing rice seeds. Laboratory tests were made to access the percentage of cell fill, the regularity of longitudinal distribution of seeds and the mechanical injury to the seeds. The conclusions were: the percentage of cell fill ranged from 103.5 to 113.3% in the best operational conditions; the seed metering accuracy reached at outlet of the seed tube, expressed as acceptable time, was 34.5%; both the level of seeds in the hopper and the lateral inclination of the seed meter did not statistically affect the accuracy and, finally, the prototype caused mechanical injuries to of the seeds of the order of 3.5%.

NOTA TÉCNICA: COMPARATIVO DE CARGAS VERTICAIS SOBRE MOLAS HELICOIDAIS E PLANAS E SUA APLICAÇÃO EM SEMEADORAS-ADUBADORAS

This paper studied the behavior of helical springs compression and flat spring pressure by the action of vertical loads, and aimed to analyze the possibility of replacing a set of three coil springs in parallel and concentric for a flat spring without compromising the functioning and performance of the mechanism that compose it. Existing planters in the domestic market use coil springs and these have the function of applying load on the planter’s rows. They are complex and robust systems. The study was based on calculation methods and measurements were compared and discussed. For the three coils in parallel and concentric yielded a maximum total stress of 3.157N in compression, for a displacement (deformation) of 200mm. The leaf spring yielded a maximum total effort 2.672N. The results proved possible to replace the coil springs by a single leaf spring, providing a simpler, lighter, and mostly with less parts in their system.

DESENVOLVENDO UMA ESTRUTURA FUNCIONAL DE LINHA DE ADUBAÇÃO PARA SEMEADORA DE PLANTIO DIRETO

In the search for fertilizer machinery on the market, we found there is a shortage of machines that suit the needs of farmers, because most of the times these machines have a need for power demand higher than that available in the properties, and are too big and expensive. The objective of this study was to use a systematic approach methodology, providing adequate functional structure suitable for a fertilizer row of low-power planter for direct seeding, organized by a block diagram. The chosen functional structure accomplishes the weight transfer to cut straw and to open fertilizer furrow on the same system, this functional structure will allow the creation of a simpler and more compact fertilizer row, in accordance to most of the needs of family-based farmers.

Methodology for assessment of wear rate in symmetrical soil-engaging tools

The correct evaluation and prediction of the durability of soil-engaging mechanisms are important factors in the analysis of the agricultural equipments. The wear of these tools (planters furrow openers, chisel and subsoiler rippers) is dependent on various factors, among them the soil conditions and the geometric and constructive characteristics of the tool. The wear rate of the soil-engaging tools is usually determined through loss of mass. The analysis of the variation of the geometric configuration of the tool was assessed through digital photography, afterwards a software was used to design them. The objective of the study was to use a differentiated, agile methodology of easy execution, for evaluation of the wear of soil-engaging tools. In this study furrow openers of a direct drill planter was employed as the soil-engaging tool. The results show that the wear is best determined by the digital photography than the traditional method (loss of mass). The advantage of the proposed method consists basically in its agility and precision.