Сегментно-пальцевая косилка для скашивания естественных и сеяных трав в условиях малых форм хозяйствования

Abstract

Segment-finger mowers are used mainly in forage harvesting. To improve their qualitative and operational indicators it is necessary to study the trajectory of movement, speed and acceleration of the mower knife under variable terrain conditions. For this purpose, the authors studied the influence of change of the non-axial value on qualitative and energy indicators of the mower’s cutter bar. They also determined parameters and operating modes of the mower knife with the axial knife drive mechanism. According to the results of experimental studies, it was established that while copying the field relief, the cutter bar changes the angle of inclination relative to the horizon within the limits of ±15 degrees. In this case, the non-axial value varies between 0.281 and 0.492 m with a step of one degree. The change of the non-axial value entails the change of the stroke, speed, and acceleration of the knife. Using the analytical method of kinematic study of crank mechanisms according to Artobolevsky’s procedure and performing calculations in the Excel software kit, the authors have obtained graphical relationships between the knife stroke and speed depending on the angular position of the cutter bar with the interval of 0, 5, 10, and 15. A change in the location of the cutter bar up to 15 degrees causes unequal speeds of the forward and reverse knife strokes, increasing it from 76.2 to 89 mm, which increases the energy consumption for the knife drive up to 17%. Another disadvantage of the non-axial crank mechanism of the knife drive is its dynamic unbalance, which is only partially smoothed with a counterweight. To eliminate the drawbacks, the authors have developed an experimental mower with axial arrangement of the crank mechanism on the finger bar of the cutter bar. The new design makes it possible to activate the transport position of the finger bar in the working mode of the cutter bar when bypassing such obstacles as bushes, trees, or rough bumps.