Теоретичне дослідження стійкості руху асиметричного посівного машинно-тракторного агрегату

Abstract

Goal. Theoretical evaluation of the effect of asymmetric connection of the row drill to the tractor on the stability of the movement of the sowing unit in the horizontal plane. Methods. Theoretical studies were carried out using the methods of theoretical mechanics, higher mathematics and the theory of automatic control of dynamic systems. Numerical calculations and construction of graphical dependencies were performed on a PC using the Mathcad 15.0 programming environment. Results. Practically all existing machine-tractor units for sowing row crops (corn, sunflower, soybean, etc.) are symmetrical. This is because each row seeder has an even number of sowing sections, and the ratio of the size of the tractor track to the row width of the row crop is an even integer (k). This article presents the results of research on the sowing unit, in which, with an even number of sowing sections of the seeder, the number k is equal to 3, which is odd. As a result, an asymmetric unit was obtained, in which the seeder is offset in the transverse direction from the axis of symmetry of the tractor by half the width of the row spacing, which is equal to 70 cm. In practice, such displacement of the seeder is carried out by hanging it on the tractor with the help of a specially designed transition device. Conclusions. With the use of mathematical modeling of the movement of the seeding machine-tractor unit in the horizontal plane, it is shown that the right-side transverse displacement of the planter by 0.35 m forms a constantly acting turning moment. But it has less effect on the stability of the movement of the sowing unit than the similar moment created by the marker. Calculations have established that increasing the input resistance coefficients of the tires of the tractor wheels, which can be achieved by correspondingly increasing the air pressure in them, leads to a desired decrease in the amplitude-frequency characteristics of the seeding unit’s development of the turning disturbance moment. Such a solution is more effective concerning the tires of the tractor’s rear wheels.