Design And Test Of Annular Air Blowing Auxiliary Seed Guiding Device For Corn No Till Planter

Precision sowing is an important part of maize production.The accuracy of its process affects the uniformity of plant spacing in the field.As the last link of sowing,the importance of seed guide tube process is self-evident.Domestic and foreign scholars have done a lot of theoretical research and device design for the seed guiding process of precision sowing,but there is still have problem of collision between seed and tube wall in the seed guiding process,which seriously affects the uniformity of seed spacing in the field.Aiming at the collision problem affecting the uniformity of particle spacing in the process of seed guiding,an annular air blowing auxiliary seed guiding device is designed in this paper.After a series of simulation analysis,theoretical research,orthogonal test,high-speed camera bench test,the optimal parameters of the key structure of the seed guiding device are selected.The main research contents are as follows:(1)Determination of corn seed material characteristics and establishment of modelThe material characteristics of maize varieties often planted in the Huang Huai Hai Basin of Anhui Province were determined.The basic parameters of its geometric size,1000 seeds and density were measured;Then the seed friction characteristics are measured in order to provide reference for the design of seed guide mechanism and provide data basis for later numerical simulation.(2)Simulation and analysis of maize seed guiding process based on EDEMAnalyze the movement track of seeds in the seed guide section,conduct numerical simulation of seed guide parts based on edem software,analyze the seed guide performance of different common seed guide parts,count the collision of seeds in the seed guide tube,and complete the bench test of different seed guide devices.The seed guide effect of square cross-section seed guide tube is good,the qualified rate is about 84%,and its coefficient of variation increases to a certain extent when sowing at high speed;The seed guiding effect of circular bellows is poor,the qualified rate is less than 80%,and the coefficient of variation is 20%.(3)Design optimization of annular air blowing guide parts and numerical simulation analysis of FluentAn annular air blowing auxiliary seed guiding device is designed,its key structure is studied,the factors affecting the movement of seeds in the tube are obtained through theoretical analysis,model have been optimized.The virtual simulation of the seed guiding tube is carried out by using Fluent to analyze the air flow distribution in the seed guiding device under different structural parameters,so as to obtain a better combination of parameters and carry out orthogonal rotation combination experiment,The optimal parameters of the annular air blowing auxiliary seed guiding device are obtained through analysis and optimization.(4)Bench test of annular air blowing assisted seed guide deviceUsing jsp-12 seed metering device performance test bench to carry out bench experiment,analyze the falling state of seeds in the seed guiding device through high-speed photography technology,and compare the falling situation of ordinary airless auxiliary seed guiding tube.When the forward speed is 6km / h(the speed of seed metering disc is 25.30r/min),the seed guiding sowing effect is the best in the seed guiding device,and the qualified rate can reach88.36%.The test shows that the qualified rate of the annular air blowing auxiliary seed guiding device meets the requirements of precision sowing.