Research On Technology And Device Of Conical Drum Flexible Threshing And Separation Of Corn

Corn grain harvest is the development trend of mechanized corn harvest in China.Huang-huai-hai summer corn planting area,as the best corn producing area in China,is affected by high water content during grain harvest,and has some problems,such as high crushing rate and uncleaned rate,and easy clogging of concave plate.In view of the above problems,the main research work of this paper is as follows:1)In this paper,through the research of domestic and foreign scholars and the existing threshing separation device,design a conical drum corn flexible threshing separation device.2)By studying the threshing force movement process of corn ear in threshing separation system,this paper analyzes the influence factors of the critical force of corn grain crushing and the change process of the force of corn ear collision friction.3)This paper designed a conical threshing roller;The combination threshing element;Through theoretical research and analysis,the key components such as conical spiral feeding head,flexible nail tooth and elastic short grain bar of pressure spring are designed.The threshing elements were arranged with four conical helical lines on the conical threshing drum,and the flexible threshing and separation of high moisture content corn kernel was realized by selecting proper threshing element wheelbase.Innovative design of three sections of "before thinning after dense" concave plate screen,three sections of concave plate screen structure,type,clearance is not the same,to achieve flexible grain threshing and separation;The threshing clearance and deflector Angle adjustment devices were designed to meet the requirements of threshing clearance adjustment and deflector Angle adjustment under different working conditions.4)In this paper,the conical threshing drum modal analysis,to avoid the resonance phenomenon,the conical threshing drum into the action balance simulation analysis,got the dynamic unbalance,and added a counterweight block dynamic balance compensation,finally through the dynamic balancing machine verification,in line with the relevant standards.In order to obtain the optimal working range of deflector Angle in threshing and separating device,the stress of corn ear during threshing and separating was studied by using EDEM simulation software,and finally the optimal working range of deflector Angle parameters was determined.5)Based on the conical threshing drum separation device,a test bench was built in this paper.Under the conditions of three water contents,single factor tests were carried out on the rotational speed of threshing drum,feeding amount,threshing gap and diversion plate Angle,and the appropriate parameter ranges of the four test factors were obtained.The orthogonal experiment of four factors and three levels was carried out under the harvesting condition of corn water content of 28.45% and 33.12%,and the primary and secondary order of the influence of each experimental factor on corn grain breaking rate and undepurated rate under the condition of high and low water content was analyzed.And get experimental factor analysis in high and low moisture content of corn grain crushing rate and when not to take off the net rate of work best when the optimal combination of the parameters,and compared with conventional threshing separation unit test,the results show that the roller speed and feed rate on the grain crushing rate is larger,the influence of threshing roller rotation speed and clearance on the degree of influence not to take off the net rate is larger;Under the conditions of low water content,the threshing effect is the best under the conditions of feeding amount of 8kg/s,drum speed of 450 r/min,threshing gap of 45 mm,and diversion plate Angle of 70°.Under the conditions of high water content,The best threshing effect was achieved under the conditions of feeding amount of 7kg/s,drum speed of 450 r/min,threshing gap of 40 mm and diversion plate Angle of 75°.Compared with the conventional threshing separation device,the grain breakage rate of low moisture content decreased by 39.4%,the uncleaned rate decreased by 63.9%,and the grain breakage rate of high moisture content decreased by 45.5%.The undepurated rate was reduced by 66.7%,which was better than the conventional axial-flow threshing separation device.