Design And Experiment Of 4DC-1 Vibrating Green Onion Harvester

Although the planting area and yield of green onion rank the first in the world,its mechanized harvest level is low.Aiming at the problems of low harvesting efficiency,nonseparation of green onions and soil,and high labor intensity of the existing segmented green onion harvester,a vibrating green onion harvester was designed.It can complete the working process of simultaneously digging,loosening the soil,clearing the soil and laying the green onions,which has no direct contact with scallion in the whole harvesting process.It effectively solves the problems of non-separation of onion soil,low efficiency,large damage rate in the existing scallion harvester.The main research contents and conclusions are as follows:(1)Based on the existing segmented scallion harvester in the market,combined with the domestic agronomic requirements of green onion planting,the whole design scheme of the vibrating scallion harvester is determined.The machine is mainly composed of crawler chassis,digging device,vibrating soil removal device and other key components,which is suitable for the single ridge and single row planting mode of scallion.It can realize the excavation,loosening the soil,clearing the soil and laying the green onions at one time and meet the requirements of excavation depth of 10 ~ 25 cm,planting row spacing of 70 ~ 90 cm and high ground clearance.(2)The key parts of the scallion harvester were designed in structure and parameters.The walking mode and structure of the crawler chassis were determined.Then,in order to adapt to different planting patterns,the digging device realizes the adjustment of digging depth and angle by the hydraulic system,and the digging shovel adopts arc structure,which is conducive to loosening and breaking soil,and avoiding backwater.And the vibrating soil removal device mainly realizes the loosening soil and orderly laying operation of scallion through the reciprocating swing of the sieve soil net,so as to improve the harvest quality and efficiency.(3)Finite element analysis and kinematic simulation analysis of key components were carried out.Based on ANSYS,the finite element statics analysis of the frame and digging shovel were carried out respectively.The results showed that the maximum deformation of the frame is 1.42 mm and the maximum stress is 173.07 MPa.Under the same parameters,the maximum deformation of arc digging shovel is reduced by 89% and the maximum stress is reduced by 52% compared with triangular shovel.The kinematic simulation analysis of the vibration soil removal device was carried out by ADAMS.The relationship between the speed of the eccentric wheel,the angle of the screen surface,the amplitude of the sieve soil net and the motion state of the screen was studied,and the corresponding acceleration curve was obtained.Based on this,the main influencing factors of the subsequent tests were determined.(4)According to the design scheme of the whole machine and the design of key components,the prototype of green onion harvester was trial-produced.The response surface test based on box Behnken design principle was carried out.Response surface analysis and parameter optimization were carried out on the test results,and the best working parameters of the whole machine were obtained.The field verification test results of the green onion harvester showed that the green onion rate is more than 98% and the damage rate is less than 4%.The main indexes conform to the General Technical Specification for Self-propelled Green Onion Harvesters,and all indexes meet the requirements of green onion harvesting operations.