Design And Experiment Of Quasi-spherical Hill-drop Seed-metering Device Based On Discrete Element Method

In view of the problems of low mechanization degree of beans,and poor adaptability of machinery in hilly areas,a bean seed-metering device was designed and a seed metering wheel component was proposed.This can be used for large seeding wheel of soybean,red bean,pea and small seeding wheel of mung bean.Through theoretical,simulation and bench test research,the structural parameters and working parameters of seed metering device were determined.Can meet the sowing requirements in hilly areas.The following are the key research findings:(1)Experimental study on seed physical parameters.Physical parameters of seeds,such as triaxial size,1000-grain weight,and density,as well as mechanical properties of seeds and different materials,such as friction coefficient and collision recovery coefficient,were measured and studied in an experimental investigation.(2)Seed-metering device structural parameter design.The overall structure of the seed-metering device was built and its functioning principle was assessed based on seed size,physical properties,and sowing agronomic needs.And structural parameters of main components are designed.(3)Simulation analysis of seed discrete element parameters and working process of seed metering device.The seed key discrete element simulation parameters are calibrated based on response surface method.Then,the major structural characteristics of the seeding wheels were simulated and optimized using the discrete element method.The seeding performance of the seed-metering device was greatest when the hole inclination angle of the large seeding wheel was 15.95°,the breadth was 12.86 mm,and the depth was 10.11 mm,according to the simulation findings.The qualified rate for soybean was93.78%,the multiple rate was 2.49%,and the missing rate was 3.73% at the time.The seeding performance of the seed-metering device was optimum when the hole inclination angle of the small seeding wheel was 14.71°,the width was 7.98 mm,and the depth was5.98 mm.Mung bean had a qualifying rate of 93.98%,a multiple rate of 2.33%,and a missing rate of 3.69% at the time.(4)Bench test of seed-metering device.Single factor experiment was carried out on the working speed.The results showed that with the increase of working speed,the qualified rate of soybean seeds increased first and then decreased,the rate of multiples reduced,while the rate of missing rate and leak seeding increased.Furthermore,there was no discernible trend in the hole diameter qualifying rate.The seeding performance of the seed-metering device was optimal for soybean when the working speed of t he large seeding wheel was 3.7 km/h,the hole width was 12.8 mm,and the hole depth was 9.7mm,according to response surface test findings.The qualified seeding rate was 91.2%,the multiple rate was 4.2%,and the missing rate was 4.6% at the time.The seeding performance for mung bean was optimum when the woring speed of the small seeding wheel was 4.1 km/h,the hole width was 7.9 mm,and the hole depth was 6.1 mm.The qualified rate was 90.8%,the multiple rate was 4.2%,and the missing rate was also 5.0%at the time.The adaptability test of various bean seeds demonstrated that the seed-metering system was well-suited to red beans and peas,with a qualifying rate of more than 85%,far above national standards.