Method and results of the evaluation of the influence of the energy of grain recovery, contacting in the head with header fairing on its parameters and quality of work

Abstract

When harvesting grain crops with combine with combining fairing, the process of contact of plants with its fairing includes the impact of the head of the plant on the surface of the fairing, and movement along its surface. The greatest probability of loss of those head grains that contact through the scales covering them with the fairing of the header was analyzed. The type of impact of these grains depends on the shape of the fairing and the angle of inclination of the plant. At the direct impact of the speed before and after impact are proportional to the recovery factor and can be sent in the forward or reverse direction. If the impact is oblique and the deviation of the velocity vector is within the angle of friction the velocity after impact is determined on the basis of Newton's dry friction hypothesis. In grain crops, a stalk is of low stiffness, and, according to our data, compensates for the damping properties of the grain covering the scales. When the head strikes, the grains acquire the kinetic energy expended on the deformation of the contacting surfaces (the lost energy) and the energy of recovery. The loss of grain will occur if the energy of grain recovery is greater than the energy required for its separation. The purpose of the research, the determination of the energy released during the restoration of the head grains, contacting through the scales covering them with the header fairing. The method was tested by comparing the renewal energy of the grain of winter wheat, which is insensitive to the contact of the head with the surface of the fairing made of steel and high-strength polymers. It is established that on the eighth day of harvesting, with a breadmaking humidity of 9-11 %, the work required to separate one grain from the head is reduced to 0,0015 J. Under these conditions, the harvesting unit equipped with a combing header with a fairing made of steel can work without loss of grain in the first phase of interaction with it at speeds up to 2,3 m/s, and with a header, the fairing of which is made of ultra-high molecular weight polyethylene, at speeds up to 3,5 m/s.