Research And Experiment Of Quantitatively-laying And Self-propelled Green Onion Combine Harvester

Aiming at the problems of low efficiency and poor quality of green onion combined harvesting equipment,combined with the agronomic system and physical and mechanical characteristics of Japanese steel green onion,the structure design and theoretical analysis of crucial devices such as the digging and shaking device,the flexible holding and conveying device,the quantitative collection and laying device of green onion were carried out.The structure improvement design,simulation analysis,and experimental verification analysis of the digging and shaking device were carried out.The technical mode,essential technology theory,and mechanism form of green onion combined harvesting were determined.The critical technical problems of green onion combined harvesting were solved,and the technical level of mechanized harvesting of green onion was improved.The main research contents of this paper are as follows:(1)Experimental study on physical and mechanical properties of green onion during the harvest period.The physical characteristic parameters such as primary dimension,density,and moisture content of Japanese steel green onion were measured.The mechanical characteristic parameters such as maximum pressure resistance,shear resistance,bending resistance,and tensile resistance of Japanese steel green onion during the harvest period were determined by tensile,compression,bending,and shear mechanical properties test of green onion white.(2)Study on the whole scheme of quantitatively-laying and self-propelled green onion combine harvester.The agronomic system of Japanese steel green onion and the research status of green onion harvesting technology and equipment at home and abroad were investigated.The design scheme and technical route of the quantitatively-laying and self-propelled green onion combine harvester were put forward.The working principle and structural characteristics were analyzed.The main technical parameters such as the whole machine’s size,the supporting power,the number of working rows,the adaptive row spacing,and the mechanical-hydraulic combined transmission system were determined.(3)Study on the critical components of quantitatively-laying and self-propelled green onion combine harvester.Aiming at the three critical links of the digging and shaking,the holding and conveying,the collection and laying in the process of green onion combined harvesting,three critical components of the shovel-screen combined digging and shaking device,the wide-width flexible holding and conveying device,and the quantitative-orderly collection and laying device were studied and designed.The theoretical analysis mathematical model was constructed,and the critical technical parameters were clarified.(4)Improved design and discrete element simulation analysis of the shovel-screen combined digging and shaking device.Aiming at the problems of large power consumption and easy accumulation of soil in digging and shaking device,the digging shovel,the shaking screen,and the soil loose and tillage device were improved,the discrete element simulation model of green onion ridge in the harvest period was constructed.The simulation tests of marching resistance,green onion ridge soil particle deflection effect,and soil particle flow effect before and after the improvement were carried out.The feasibility of improving the structure was determined.(5)Field experiment of quantitatively-laying and self-propelled green onion combine harvester.The field test analysis was carried out on the shovel-screen combined digging and shaking device before and after improvement,and the feasibility of the improved structure is was verified.The forward speed of the whole machine,the horizontal inclination of the digging shovel,the frequency of shaking screen,and the sensing distance of the green onion platform as the test factors,and the percentages of green onion impurities and the percentages of green onion damage as the evaluation indexes,the orthogonal test of four factors and three levels was carried out.The optimal working parameters were obtained as follows:the forward speed of the whole machine is 0.70 m/s,the horizontal inclination of the digging shovel is 30.00°,the frequency of shaking screen is 3.60 Hz,and the sensing distance of the green onion platform is40.00 mm.The percentages of green onion impurities are 3.29%,the percentages of green onion damage are 1.79%,and the operation efficiency was 0.15 hm~2/h in the field test,which met the requirements of the green onion harvest.The research results can reference the structural improvement and operation performance optimization of the self-propelled green onion combine harvester.