The study of the technological process of the operation of the stalk lifter when mowing down dead grain and leguminous crops

Nowadays, the roller reapers and headers of grain harvesters, when mowing down dead grain and leguminous crops, are equipped with stalk lifts. The successful completion of the process of raising flat and cut stems depends on the correct choice of the angle of inclination of the wing of the stem lift. In existing designs of stalk lifts, the angle of inclination is set less than the angle of friction of the stalk on the surface of the device. However, with this approach to choosing an angle with a moist stalk and large fluctuations in the microrelief of the field surface, there are observed the enveloping of the wings of the stalk lifters and the process of unloading of the grain mass. This suggests that knowledge of the coefficient of friction of the stems of harvested crops in the design of stem lifters is not enough. Therefore, there is a need to study the process of lifting the stems of grain and leguminous crops. The aim of the study is to determine the theoretical dependence of the magnitude of the rise of the stems on the structural and technological parameters of the operation of the stemlifting device of harvesting machines when mowing dead grains and legumes, as well as the technological properties of the harvested crop. The article discusses the process of lifting a cut stem along the surface of the stem lifter, as well as a laden uncut stem, taking into account the strength of resistance to bending and weaving of the stems. The forces acting on the stem are determined. The assumption is made about the absolute inelasticity of the impact of the stem on the surface of the device. Based on the obtained mathematical model, graphs of theoretical dependencies of the maximum possible movement of the stem and the height of its rise depending on the speed of the machine and the angle of installation of the wing of the stem lifter are constructed. Analysis of the obtained dependences allows us to conclude that the design parameters of the stem lifter are determined both by the sliding friction coefficient of the stems of harvested crops and by the speed of the harvester and the strength of the bending resistance of the stem as well.

stem lifter, friction angle, tilt angle, lifting height, speed, dead stems, moving