Experimental Study And Simulation Analysis On Front And Back Splitting Disk Soil Coverer

With the development of corn planting technology in China and the precision seeding technology,it becomes more and more vital that the improvement of the design of precision sowing machinery of all aspects of the work.It is urgent that the application and development of new structure and new principle in precision seeding machine.Precision seeding refers to the plant（grain）spacing and the row spacing and sowing depth,which are strictly controlled,a single grain sowing technology.Four technical indexes affect the actual precision seeding precision value,which requires not only the accurate metering investment,accuracy in plant spacing,row spacing,single grain sowing,at the same time,it also requires the excellent performance of the soil.And reasonable structure and excellent performance of the soil cover is conducive to not only the spacing and seed spacing uniformity,but also the growth and late seed early water absorption,lighting,etc.In order to reduce the impact of soil on the displacement of the seeds,and to improve the uniformity of the distribution of the seeds and the consistency of the thickness of the soil cover,this paper designed a new type of soil cover,of which a pair of disks was added at the back end of the existing disc soil covering device.The basic idea is to turn traditional one-time covering into two times covering,and the soil volume of the latter is equivalent to the former,which avoids too much volume of the one-time soil covering and the large displacement of seed.The seed is covered for the first time by the front small cover plate,and then the second covering is accomplished through the large cover plate at the back.After the first covering,the seed has been positioned,the second covering has no impact on the seed,which can not only achieve the thickness of covering soil and improve soil quality requirements but also provide a good environment for seed germination,and better achieving the precision seeding.SolidWorks software was used to establish the three-dimensional model of the new type soil covering,and the machining was also completed.Adopting the uniform test scheme,the soil bin test was carried out by means of the new type one and also the traditional soil cover.Based on the analysis of the soil bin test,the optimal structure was selected and got the regression equation of soil thickness and seeds displacement Y1 and Y2:Y₁=58.5+0.4A+1.28B+0.7C+0.15D+0.15AB-0.44AC-0.25AD-0.42BC+0.18BD-0.21CD+0.3A²-0.34B²-0.009625C²-0.6D²Y₂=4.39+1.03A+0.25B+0.14C+0.14AB-0.22AC+0.0075BC-0.095A²+0.047B²+0.075C²Regression model Y1: A,B,C,D representing small disc diameter,large disc diameter,covering distance and plate opening angle.Regression model Y2: A,B,C representing small disc diameter,large disc diameter and plate opening angle.It used EDEM software for optimal coverer covering process simulation analysis.The simulation results were consistent with the analysis of the soil bin test results and verified the feasibility of discrete element method,it provides new method for the further design and enrich the rich precision seeding technology and theory.