Study On Top-feed Tangential-flow Double-drum Picker For Both Dry And Wet Peanuts

Peanut is the world,and also the important cash crop and oil crop.Although China is a big country of peanut production and export,the mechanized harvesting level is relatively low.Fruit picking is the essential link of peanut mechanical harvest,and also the key to affect the harvest efficiency and pod quality.Aiming at the problems of short effective stroke,low cleaning rate of fresh and wet peanuts,and high breakage rate of dry peanuts,this paper combined with the follow-up research of National Natural Foundation Project(No.:51575367)and the actual production of Zhengzhou Shuangfeng Machinery Co.,LTD.,started from the physical and mechanical characteristics of peanut plants.A kind of dry and wet peanut picking machine with double drum was developed and its performance was tested.The main research contents and conclusions of the paper are as follows:(1)Experiment on plant characters and fruit picking characteristics of peanut.It mainly included the measurement and statistical analysis of plant character parameters of typical peanut varieties.The variation of water content of peanut plant and the variation of tensile strength of peanut stalk node,seedling stalk node and stalk with water content were analyzed.The variation of tensile and shear strength of peanut stem with water content was analyzed.The friction characteristics of peanut plants and its variation with water content were analyzed.The variation of peanut capsular compressive strength with moisture content was analyzed.(2)The method of picking peanut fruit by cutting flow with upper feeding was put forward.Based on the analysis and comparison of the advantages and disadvantages of the existing peanut fruit-picking device,the principle of "up-feeding cutting flow fruit-picking",which can be used in dry and wet states,was put forward.Based on this,the principle and overall scheme are designed.(3)Analysis of peanut picking process and design of key components.Through the dynamic analysis of peanut fruiting process,the parameters of peanut fruiting movement and their effects on peanut feeding,fruiting and straw discharge were clarified.The optimum position of the upper feeding inlet and the 45° feeding Angle were determined.Three sets of teeth are adopted,among which the lower side of the feeding inlet is arranged in accordance with the semicircle,triangle and rectangle,and the fixed tooth clearance adjustment mechanism is provided;The diameter of the two fruit picking rollers is 450 mm and the fruit picking teeth are rectangular.The first and second stage concave screen with adjustable fruit picking gap is designed.(4)Design of transmission and cleaning device of peanut picker.Design the transmission system and determine the transmission ratio at all levels;The fan and vibrating screen are designed.The wind speed is 10m/s,the air volume is 0.97m3/s,the outlet height is 0.135 m,the total pressure is 139.15 Pa,the outer diameter of the impeller is 300 mm,and 6 blades are taken.The maximum amplitude of the designed shaker is 40 mm.(5)The performance test of peanut fruit picking machine prototype was carried out.The peanut variety Yuhua 22 was selected,and the fresh wet peanut was selected as the fruit picking object.The single factor test and the three factor and three level orthogonal test were carried out with the fruit picking roller speed,fruit picking clearance,the clearance between the fixed tooth top and the fruit picking tooth top as the test factors,and the cleaning rate,damage rate and entraining rate as the test indexes.The relevant constraints were determined,and the optimal working parameters were obtained,namely,the rotation speed of the fruiting drum was375.00r/min,the clearance of the fruiting clearance was 21.70 mm,and the clearance of the fixed tooth tip and the top of the fruiting tooth was 5.00 mm.The cleaning rate,breakage rate and entraining rate are 98.84%,1.90% and 0.85%,which meet the operation requirements.