Design And Performance Test Of The Precision Seed-metering Machine For Small Seeds

Shanxi Province is one of the main producing areas of small grains,with the yield and quality of millet and prosomillet at the forefront of the country.Recently,with the healthy food gaining more and more popularity,the planting area of small grains including millet is expanding constantly, becoming the focus of the adjustment of agricultural industrial structure.But the precision seed-metering successful equipment suitable for hilly and mountainous areas that is used to seed millet and prosomillet is less. Thus this paper are researching the precision seed-metering machine for small seeds to meet the requirements of small grain seeding.Main research contents are as follows:1.Mechanical properties test and analysis on small grains including millet and prosomillet was conducted.The static and dynamic friction coefficient between different seeds with different materials was measured by the Friction Coefficient Measuring Instrument,acquiring the static and dynamic friction coefficient of small grains including millet,providing the parameters for the performance analysis.2.The mechanical properties of compression on small grains including millet was studied.The tests of compression mechanical properties on small grains including millet was conducted by the Texture Analyzer,acquiring the correlation of extrusion force and extrusion deformation and extrusion damage applied on the seeds,providing the support for the determination of maximum compression bearing capacity during the process of seed-metering.3.Aiming at the application in the small grain crops planting metering devices include ring groove, shaped spiral groove,eye socket wheel,etc,comparative analysis was made,mainly about the damage degree of seeds,the similarities and differences between these phases of dynamic characteristics,motion state change and friction characteristics in filling region, cleaning region, protection region and seeding region,etc,providing the basis for the choice of the structure parameters of seed metering device.4.Considering all the analysis results above, eye socket-ring groove small grain seed metering device and the structure of small precision seed-metering machine were designed.The test of static seeding performance and sowing performance of the machine were conducted,choosing and optimizing the structure parameters.The main parameters are as follows:the shape parameters of eye socket that is inverted cone type are that the large diameter 4.82 mm,the small diameter 3 mm,the depth of eye socket 2.5 mm;the radius of the eye socket wheel is 70 mm,30 mm in width, 20 in the number of the double row eye socket, the distance between two rows of litter eye center is 14mm and the distance between the center of single row nest and the seeder edge is 8mm.The seeding machine was combined with the arrow shovel type furrow opener, iron wheel pressing device,conventional drive system and sowing machine frame.On the basis of the compression ultimate value and the force displacement damage degree, stability and uniformity of seeding,the best speed of the seed wheel is 14r/min when seed-metering machine plating millet,the best speed of the seed wheel is 12r/min when seed-metering machine planting prosomillet.