Effect of soil type, machine geometry, and working conditions on draft force of a moldboard plow and a disk plow
Subject Areas :
Keywords: soil cutting, soil displacement, friction force, theoretical models, mechanical laws,
Abstract :
Effect of soil type, machine geometry, and working conditions on draft force of a moldboard plow and a disk plow Iman Ahmadi 1 1- Assistant professor of Mechanics of agricultural machinery, Department of Agronomy, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran i_ahmadi_m@yahoo.com Abstract One of the most important factors that affect the efficiency of tillage implements is the implement draft. If the two components of the exerted force from tillage implements to the tractor that are parallel and perpendicular to the direction of motion are calculated, the parallel component will be the machine draft force. In this paper, effects of soil, machine, and working condition parameters on the components of the moldboard and disk plow draft forces are considered utilizing the two mechanical models. To obtain the considered mathematical formulas, values of each independent variable has been varied in the rage [50%Xbase , 150%Xbase], and their corresponding dependent variable was calculated. Finally, using the Excel software the equation and its R2 value were obtained. According to the results of this study, the increase in the percentage of fine-grained particles of soil led to the increase of the portion of that component of draft force that is derived from the soil cutting process. On the other hand, the minimum values of the specific draft force of the moldboard plow regarding to the plowing depth, took place in the range of 15 to 20 cm. Furthermore, the value of 40 cm was given as the optimum width of the bottom of the moldboard plow, and the value of 80 cm was obtained as the optimum disk diameter of the disk plow. Moreover, the value of 15º was resulted as the best rake angle for the disk plow regarding to the efficiency of the plow. Keywords: soil cutting, soil displacement, friction force, theoretical models, mechanical laws
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