Design And Experimental Research Of Side-Mounted Guided High Speed Precision Seed Metering Device For Soybean

In order to solve the problems of low seed filling quality,poor seed cleaning effect and unstable seed transfer of mechanical seed metering device under the condition of high speed operation,this study designed a side-mounted guided soybean high-speed precision seed metering device based on the idea of guided seed filling.Theoretical analysis,discrete element method,bench test,field test and other methods were comprehensively applied.The structure design,simulation optimization and experimental verification of seed metering apparatus were carried out,which improved the high-speed performance of seed metering apparatus,and provided theoretical and technical basis for the development of mechanical high-speed precision seed metering apparatus.The main research contents and conclusions are as follows:（1）Structural design and theoretical analysis of side-mounted guided soybean high speed precision seed metering device.In order to guide seed filling,a side-mounted guided shaped hole was designed.Through the dynamic analysis of seed filling,seed cleaning and seed transfer process,the key structural parameters affecting seed filling and seed cleaning were obtained（type hole width L₁,seed taking cavity height L₂,seed filling Angleα,opening Angleβ）,and the filling force model was established.The results showed that:In the process of seed filling,the side-mounted guided structure can gradually increase the filling force and effectively improve the filling quality.（2）Simulation test and structure optimization of soybean high-speed precision seed metering device with side-mounted guidance.The discrete element method was used to conduct single factor test on the key parameters that affect the performance of seed metering device to explore the influence of each parameter on the test index.The regression equation between the parameters and the experimental indexes was established through the combined test of center rotation,and the optimal combination of structural parameters was optimized:seed filling Angleαwas 11.5°,opening Angleβwas 119.05°;The bench test results show that the qualified index is not less than 95.27%and the missed seeding index is less than 4.73%at the operating speed of 4～14km/h,and the error is within 1.8%with the simulation results,indicating that the optimized test results are accurate and reliable.（3）Vibration performance test of side-mounted guided soybean high speed precision seed metering device.By analyzing the vibration of seeder and seeder,the vibration parameters affecting the performance of seeder were determined,and the trajectory equation of seed seeding was established.Vibration bench test was carried out with high-speed photography technology to explore the influence of vibration parameters on seed seeding uniformity.The results showed that the seed seeding trajectory under vibration condition was consistent with the theoretical one.The field test results showed that the qualified index was not less than85.46%,the missed sowing index was less than 10.32%,the reseeding index was less than4.22%,and the coefficient of variation of plant spacing was less than 29%under the condition of high speed operation,which met the requirements of precision sowing.