Design And Experiment Of Half-cup Type Potato Seed-metering Device

As an important food crop in the world,the potato is widely cultivated.As a big country of potato production,there are still some problems.In order to improve the level of mechanization of potato cultivation and the quality of sowing,this topic combines the existing potato sowing technology and planting machinery at home and abroad,Aiming at the problems of high leakage rate,manual labor intensity and poor versatility of the current potato seeder seeding device,a half-cup type potato seed metering device was researched and designed.It is composed of seed chain,seed box,driving wheel and driven wheel.Combined with the study of physical characteristics of potato,the basic parameters were determined,and single factor and orthogonal experiments were performed on the test bench,respectively,and the degree of influence of related factors on seed-discharge performance was analyzed to obtain a reasonable combination of parameters.The main research contents and conclusions of this topic are as follows:(1)Study on the physical characteristics of potato seed potato.The main test subjects were 30-50 g,a variety of small whole potatoes and cut potatoes of the 15th Holland.Their physical properties were studied and their basic physical properties were determined,including the shape and size of potato seed potatoes,bulk density,and water content.The rate,friction angle,friction coefficient and angle of repose provide reference and theoretical basis for the structural parameters and design of key components of the potato metering device.Potato No.15 in the Netherlands is mainly45 to 55 mm in length,40 to 45 mm in width,35 to 45 mm in thickness,and its shape index is mainly in the range of 100 to 160.The calculated shape index(f)is mainly Focusing on the range of 100 to 160,the look-up table shows that it is mainly spherical;after determining,the average moisture content of fresh seed potato is79.26%,and the bulk density of the seed potato under this moisture content is643.37kg/m~3;The self-made slope meter measured the rolling stable angle of the seed potato on the steel plate was 13.4°;the sliding friction angle of the seed potato seed coat on the steel plate was 30.1°,the sliding friction coefficient was 0.58,and the seed potato cut section of the seed dressing of the plant ash was on the steel plate.The sliding friction angle was 32.1°,and the sliding friction coefficient was 0.63.The natural angle of repose of the seed potato,which accounted for 70%of the total potato weight,was between 29°and 31°.(2)Design and analysis of structure and key components of seed metering device.The main structure and working principle of the half-pot spoon potato seed metering device were described,and the key components of the seed metering device were designed,including:the design of the structure parameters of the cup spoon and the recovery plate,and the distance between two adjacent spoons Arrangement method,selection of seed chain type,calculation of drive wheel diameter,relative installation position of drive wheel and two driven wheels,design of structural dimensions of seed box,chute and guide board,final calculation and derivation of seed chain The theoretical relationship between speed and tractor speed.By analyzing the analysis of the four working processes of seed metering,seed clearing,seeding,and seeding,the foundation for the further optimization of the structure of the key components of the metering device is laid.(3)seed meter performance test.Through analysis and comparison,single factor and orthogonal test were finally performed on the self-built seed metering test stand.Through the seeding performance test,it is clear that the angleαbetween the seeding chain and the horizontal plane in the seeding area has no obvious effect on the leakage rate,and thus it will not affect the seeder seeding performance,butαwill directly affect the length of the whole machine,and the smallerαis.The longer the machine length,and the phenomenon that the seed potatoes are carried when picking the seed,taking into account theαtaking 75°;taking the qualified index,replay index and missed sowing index as the test index,the driving wheel speed,the cup spoon model and the clear seed The single-factor test was carried out at the angle of the test conditions,and the influence of the rotation speed of the driving wheel,the model of the cup spoon,and the angle of seed clearing on the test index was defined;through the analysis and processing of the orthogonal test data,the performance factors of the seed meter were tested by various experimental factors.The order of the impact is the rotation speed of the driving wheel,the cup spoon model and the seed clearing angle.The optimal parameter combination is the driving wheel speed 37.5r/min,the large cup spoon,the clear seeding angle-5°,and the performance of the seed meter is best at this time.The qualified index was 93.74%,the multiples index was 3.99%,and the misses index was 2.27%,which satisfied the potato sowing requirement.