Design And Experimental Study Of Rice Precision Hill Direct Seed Metering Device

In recent years,the rice direct-seeding planting model has been rapidly promoted and planting areas have been increased year by year,the hybrid rice sown areas are also increasing,therefore,farmers are in urgent need of seeders with reliable performances,simple structures and moderate costs that suitable for hybrid rice precision direct-seeding.In order to meet the agronomic requirements of hybrid rice precision direct-seeding,the properties of hybrid rice seed were studied in this paper.Based on the experimental results of material properties,the vane seed-protecting model-hole roller seed metering device suitable for hybrid rice seeding is designed;though theoretical analysis in seeds filling,seeds protection,seeding process and simulation analysis the sowing performance of the metering device with EDEM software,finally an indoor bench testing on the metering device was performed and verification analyzed.The main contents are as follows:(1)Selecting seeds of three hybrid rice varieties,including Guofeng No.1,Gangyou 898,and Gangyou 3551 as research objects.Then measured the parameters of three-axle size,thousand seed weight,natural caesural angle and sliding friction angles under different material conditions of these seeds,which provide references for the design of the key components of the metering device.(2)According to the agronomic requirements for dry direct-seeding of hybrid rice,combined with the properties of rice materials,a kind of vane seed-protecting model-hole roller seed metering device was developed.The structure parameters of the devices and the main factors affecting seeding performance were determined after analyzing and studying the working principle of the seed metering device,as well as the process of seeds filling,seeds protection and seeding process.(3)A geometric model of the metering device was built by SolidWorks,and imported into EDEM software in the IGS format,established a rice seed mode in EDEM.Then the simulation and analysis of sowing performance were carried out with rotation speed and rice grains sizes selected as experimental factors.(4)Through the approach of Quadratic Orthogonal Rotation Design,a bench testing on metering device was conducted by two factors five levels with rotation speed of the metering device and sphericity representing the grains sizes as experimental factors.Meanwhile,the test data are processed via Design-Expert 8.0.6 software,finally the best parameter combination were obtained then verified in further bench test,the test proved it accords with agronomic demands.