Design and Experimental Research of a Comb-Type Buckwheat-Harvesting Device

In this study, a comb-type buckwheat-harvesting device was designed and tested for use in hilly areas and on small plots of buckwheat in China. The device uses semi-feeding and allows for threshing before cutting. Through the parametric design of the threshing mechanism, a dynamic model of the comb teeth’s striking of buckwheat plants was established. The effect of the machine’s forward speed and the speed of the comb teeth on the threshing rate was explored via a single-factor experiment. Based on the simulation test and actual operations, an orthogonal experiment with three factors and three levels was performed, using the machine’s forward speed, the speed of the comb teeth, and the tilt angle of the threshing mechanism as the factors, and the threshing rate, breakage rate, and loss rate as the indicators. Regression equation models were established for the relationship between the influencing factors and the threshing rate, breakage rate, and loss rate, and a response surface analysis of the influencing factors and their interaction was carried out. The results showed that the speed of the comb tooth had the greatest influence on the threshing rate, breakage rate, and loss rate, followed by the machine forward speed; the tilt angle of the threshing mechanism had the least influence on the threshing rate, breakage rate, and loss rate. By optimizing the multi-objective parameters of the regression equation models, reasonable parameters were obtained for the influencing factors: the machine forward speed was 0.5 m/s, the speed of the comb teeth was 1.2 m/s, and the inclination of the threshing mechanism was 45°. Under these conditions, the threshing rate was 80.10%, the breakage rate was 1.83%, and the loss rate was 7.03%.