| In order to solve the problems of seeding difficulties in hilly areas,such as large workload and difficulty in thinning seedlings,according to the agronomic requirements of millet seeding,the use of three-dimensional modeling,theoretical analysis,simulation analysis and other methods to research and analyze the design of seeder,designed a kind of suitable for the operation of hilly mountain millet precision seeder.The main research contents and conclusions are as follows:(1)According to the hilly mountains on the seeder restrictions and the agronomic requirements of millet sowing,the design of the whole structure of the seeder,the seeder can be completed at a time,seed,seed,guide,ditching,covering soil,suppression and a series of operational processes.(2)Completed the selection and design of the key working parts of the seeder.To determine the supporting power,choose the 204 Dongfanghong small four-wheel tractor with sufficient power and convenient steering to provide forward power for the seeder.In order to meet the requirement of 20 cm from the ground in the transportation process of the planter in hillock and mountain areas,the height and extension length of the upper and lower suspension rods can be determined.Through the Solid Works software,the coordination relationship is checked,and it meets the GB/T 1593-2015 standard of rear three-point suspension device of agricultural wheel tractor.The trencher adopts double disc trencher,and the four-bar copying mechanism is designed at the connection between the front segment of seeder and the frame,which can solve the problem of the inconsistency of seeding depth in the hilly process.It is proposed to adopt the electromagnetic vibrating linear seed platter trial-produced by the research group,which has no complex mechanical transmission and good uniformity and stability of seed platter.The soil on the side of the ditch opened by the trencher can be gently scraped back by the scraper mulcher.The suppression wheel does not need to provide mechanical power to the seed platter and only needs to reach a certain diameter to reduce slippage during sowing.(3)By calculating the position of the seed arrangement device,the number of rows and row spacing of the sowing group,and considering the fixed mode of the trencher,the soil covering device and the suppression wheel,the structure size of the seeder frame was determined.The three-dimensional modeling of the whole machine was completed by Solid Works software,and the motion state of the machine was analyzed.And use ANSYS software to carry on the static simulation to the seeder frame,get the stress,strain and displacement of the frame analysis cloud map.The maximum deformation is 0.23216 mm,which occurs at the joint of the pressing wheel.Although there is no obvious influence on the seeding effect,the structure should be improved.The maximum stress and strain are 5.978 MPa and 0.000273 respectively,which are far less than the allowable stress of frame material Q235,and the strength meets the design requirements.(4)The size of the seed guide tube was designed and the motion velocity equation of millet in the seed guide tube was established by mathematical modeling coordinate system.Solid Works software was used to build a three-dimensional model of the seed guide tube,which was imported into EDEM software to analyze the movement process of seeds in the seed guide tube after passing the electromagnetic vibration seed arrangement device.By analyzing the movement trace of seeds in the seed guide pipe and the velocity curve of seeds passing through the plane under the seed guide pipe,the average sowing speed of seeds was found to be 2.5m/s,which was corresponding to the third gear of the small four-wheel tractor,which was the theoretical basis for determining the zero-speed sowing of the seed planter.(5)The design of hilly mountain seeder has the advantages of ditching depth(3-5cm),row spacing(20-40cm),forward speed(1.0-3m/s),width of suspension frame and other convenient and adjustable parameters,small body,light weight and strong reliability.This study is suitable for precision seeding of mountain millet and can provide a reference for the design of small precision seeder for mountain millet. |
