Design And Experiment Of Threshing Device Of Millet Combine Harvester

With the improvement of people’s demand for grains,millet production was concerned about.Mechanized production was an important link.At present,the main way was the manual removal of millet harvested corn,and fed into the threshing device,power consumption,low efficiency.The shape of millet was special.Grain diameter of millet was smaller than others.It was difficult to thresh and clean for present combine harvester.The combine harvester was not available for the millet harvest requirements.To solve this problem,characteristics and connecting force of millet were compared with that of wheat and rice.The effects of threshing was studied.Threshing components,the rotation speed of the roller,the diagrid spacing of gravure screen and threshing was designed.3D model of threshing device was built to optimize.The threshing loss rate,threshing loss rate,entrainment loss rate,broken rate as the index,the field experiment was carried out.The single factor experiment was designed to study the effects of threshing components,the rotation speed of the roller,the diagrid spacing of gravure screen and threshing clearance on threshing effect.The orthogonal experiment was designed to contrast the threshing effects of each factor.Quadratic orthogonal regression experiment was designed to build millet threshing model and find out the optimal parameter values by using the DPS data processing system.Main Research Contents as following:1.The experiment results showed that the sequences of factors influencing the threshing performance were diagrid spacing of gravure screen,roller speed,threshing clearance,threshing components.2.Entrainment loss was the main part of threshing loss.3.When the spacing of the concave plate screen was changed from 15 mm to 7mm,the smaller the distance corresponded to the smaller entrainment loss.4.When roller speed was changed from 781r/min to 1025r/min,the threshing loss rate decreased gradually.Broken phenomenon appeared When roller speed was 1025r/min.5.Compared with impact effect of whole spike tooth and brush effect of whole trapezoidal tooth,rubbing effect of the whole rasp bar was more suitable for millet to thresh.6.When the threshing clearance was changed from 15 mm to 7mm,the smaller the distance corresponded to the smaller entrainment loss.7.Theoretical optimal parameters were that the diagrid spacing of gravure screen was 7.9mm,the roller speed was 928.3r/min,the threshing clearance was 10.4mm,the threshing components was rasp bar.