Developing a disc blade cutting system for sesame harvesting and determining its operating criteria and energy requirements

Sesame is an important field plant in which the best quality oil is taken from its seeds. In the harvest of the sesame plant, there are partial mechanization applications and it is usually removed from the field by using a shearing unit with shear cutting. Shear cutting-based mowers have a large number of parts, require constant adjustment, must be lubricated frequently and have vibration problems. The use of rotating knives eliminates these negative situations. Therefore, determining the using possibilities of the disc blades is important. In the study, an experimental setup with a disc blade working on a cut-mowing basis from harvest methods was designed and fabricated according to the sesame plant. In the experimental setup, by cutting the plant stems and making some measurements and observations, the most suitable cutting criteria which are knife mouth types and disc blade diameters were tried to be determined. The cutting qualities of the disc knives with different rim structures and the amount of energy consumed during cutting were determined. It was decided which disc blade has the lowest energy consumption and suitable cutting. In addition, plant stems with different diameters (10, 15 and 20 mm) were measured using the shear cutting method and the energy expenditure for cutting was measured and compared with the disc blade system. The friction coefficient (μ) value between the sesame stems and the blade material was found to be 0.47 ± 0.02. Plant samples moisture value was determined as 65% ± 2. Disc blade with 30° wedge angle at all stem thicknesses consumed the lowest cutting energy. For large stem thicknesses, the disc blade with a diameter of 180 mm gave the lowest cutting energy. The effect of stem thickness on the energy expended in cutting with all mouth pairs is important and more energy is required for cutting large stems. In all pairs of blade, as the disc diameter increases, the energy spent for cutting the stems decreases. Knife pairs with 30° and 45° cutting edges are the most suitable in terms of cutting qualities for cutting stems of all diameters. 180 mm disc diameter gave the best result in terms of cutting quality in different-edged disc pairs in cutting the stem of 20 mm. Considering the handle thickness, the blades arranged in pairs were found to be quite successful in terms of cutting quality compared to the ones with flat blades. The blades with diameters of 180 and 210 mm with disc diameters in differently arranged disc pairs gave the best cutting quality. The effect of the difference in stem diameter on the energy consumption per unit area in shear cutting is significant and increases as the diameter increases. The cutting energy values obtained in both shear cutting and disc cutting system were found close to each other. The disc blade cutting method can be used in the sesame harvest.