Design And Experiment Of Liquid Topdressing And Weeding Machine For Maize

It can not only increase the yield of maize,but also increase the utilization rate of fertilizer.Maize mainly depends on the root to absorb nutrients.Deep application of liquid fertilizer to the root is more conducive to the root to absorb nutrients.But at present,most of the top dressing machines in the market topdressing granular fertilizer,and the gap is low,fertilizer utilization rate is low.In order to remove weeds in the field,chemical weeding method is widely used at present.This method uses a large amount of drugs and causes certain harm to crops and growth environment.Mechanical weeding instead of chemical weeding can not only reduce the drug damage,but also loosen the surface soil.For this reason,in view of the problems of large amount of fertilizer and pesticide use and low utilization rate of fertilizer in China,combined with the requirements of Agronomy,this paper designs a kind of corn liquid Topdressing and weeding integrated machine,designs the whole machine structure and key parts,and verifies the topdressing effect and weeding effect of the machine through indoor and field experiments.(1)A liquid fertilizer and weeding integrated machine is designed,which can complete ditching,fertilizer,weeding and soil covering operations.The maximum ground clearance of the machine is designed to be 850 mm.Deep application of liquid fertilizer on both sides of the root can realize the adjustment of fertilization position;the electric mechanical weeding structure can realize the control of weeding depth and weeding speed.(2)Taking the ditching depth and ditching speed as variable factors,the ditching resistance of ditcher was simulated and analyzed by using EDEM discrete element software.The simulation results show that the ditching resistance increases with the increase of ditching speed,and there is a positive correlation.When the ditching speed is constant,the ditching resistance is positively correlated with the ditching depth.When the trenching depth is 100 mm and the trenching speed is 0.9 m/s,the maximum stress is 1.500 MPa and the maximum deformation is 0.116 mm,which meets the design requirements.The ditching resistance of the ditcher is verified by the soil tank test,and the error between the results and the simulation results is about 10%,which verifies the accuracy of the simulation model.(3)Taking blade width,blade thickness and blade welding angle of weeding wheel as variable factors,quadratic orthogonal rotation experiment was designed by using design expert software.EDEM discrete element software combined with design expert software was used to analyze the influence of various test factors on the force of weeding wheel.The welding angle and cutter tooth thickness had a significant impact on the resistance of weeding wheel,and the cutter tooth width had a significant impact on the resistance value.Taking the minimum force of the weeding wheel as the boundary condition,the optimal structure of the weeding wheel blade is obtained:the welding angle is 0°,the blade tooth thickness is 3 mm,and the blade tooth width is 40 mm.The average stress of the structure is 117.325 N by EDEM software.The simulation results are imported into ANSYS Workbench,and the maximum deformation is 0.161 mm,and the maximum stress in the working process is 11.392 MPa,which meets the design requirements.(4)The results showed that the average error of fertilizer discharge was 2.13%,the coefficient of variation of fertilizer discharge stability was 1.01%,and the coefficient of variation of fertilizer discharge consistency was 3.45%.The results of field experiment showed that the coefficient of variation of ditching depth consistency was 2.85%,and the coefficient of variation of ditching distance from seedling belt consistency was 2.16%.It had good trafficability and no blockage.(5)The order of influencing factors on weeding rate from high to low is weeding depth and vehicle speed;the order of influencing factors on injured seedling rate from high to low is speed and weeding depth.The field experiment showed that the average weeding rate was 93.91%,and the average seedling injury rate was 2.47%.