DESIGN AND EXPERIMENT OF THRESHING AND SEPARATING DEVICE OF CORN GRAIN HARVESTER

In order to find out the influence rule of threshing system parameters on threshing effect and the optimal parameter combination, the cylinder-concave clearance adjustment device is realized by "Front and back two hydraulic cylinders + Slide rail", the deflector angle adjustment device is realized by "Hydraulic cylinder driving hinge rotation" and the threshing separation device inclination angle adjustment device is realized by "Front adjustable double head pull rod". Multi-objective optimization test was carried out. The experimental results showed that the significant order of the influence of various factors on the grain breakage rate was rotational speed of roller, threshing separation device inclination angle, feeding rate, deflector angle and cylinder concave clearance. The order of significance of the influence on uncleaned material rate was rotational speed of roller, cylinder-concave clearance, deflector angle, threshing device angle and feeding rate. According to the multi-objective parameter optimization analysis, the optimal operation parameter combination of corn threshing was determined. Under this parameter combination condition, model verification test and field optimization test were carried out. Compared with the field test value after parameter optimization, the grain breakage rate decreased from 4.018% to 3.462%, and the uncleaned material rate decreased from 0.292% to 0.218%.