Research On Filling Force And Structure Optimization Of Shallow-basin Type Seed-plate Soybean Seed-metering Device

Based on the National Natural Science Foundation of China, Project Number is 51275086, the paper takes the vertical disk seed-metering device as the research object, research how to improve the filling force to adapt the high-speed operating requirement from the angle of mechanics, aimed at optimization and finalize the vertical shallow-basin type seed-metering device with high-speed operating ability. The main research work is as follows:(1) Kinds of filling force and functional mechanismFilling force is basic element which seed-metering device can complete the process of filling seed. The paper analyzes briefly the action form and mechanism of filling force of several mechanical precision seed-metering device, build the filling force model of hole, and analyzes the characteristics and laws of filling force by the granular material mechanics theory, through the theory analysis and mechanical analysis, we can know that limited to the structural characteristic of seed-metering device and granular characteristic of seeds, the filling force value as the form of compressive stress has upper limit value, and the value is small. Therefore, improve the filling ability of mechanical precision seed-metering device at high speed working condition from the angle of mechanism should focus on how to form more filling force.(2) Simulation and test device designThe paper took the vertical disk seed-metering device as the research object, made the structure design aimed to improve the high speed working filling performance of vertical disk seed-metering device. The paper improved the vertical disk to the vertical shallow-basin type seed-plate by the way of increasing the filling force kinds, and designed the vertical shallow-basin type seed-metering device according to the design requirements, then designed the simulation and test device.(3) EDEM virtual simulationThe paper built the soybean seed particle model by EDEM virtual simulation technology, simulated the working process of vertical shallow-basin type seed-metering device, made the analysis on the working process by the EDEM post-processing module, then researched the working mechanism; at the same time, analyzed the influence laws of seed-plate、working speed、and angle of seed-plate on the filling rate b y the method of multiple factors combination experiment, got the optimal structure parameters combination of seed-plate, providing quantitative basis for the product.(4) Experimental researchTo observe accurately the working features of seed-metering device and the moving state of seeds in the cavity, the paper utilized the high-speed photography technology to shoot the working process of vertical shallow-basin type seed-metering device at the JPS-12 computer vision precision metering device detection test at the different rotational speed, to observe and analyze the cleaning and throwing process, providing the reference basis for improving the metering device design and improving the work performance.(5) Structure optimizationThe paper can observe clearly the re-seeding phenomenon of hole by the EDEM simulation and high-speed image, and processing the hole is complex, therefore, improve the structure of vertical shallow-basin type to a new type seed-plate, and design a hole which can avoid the re-seeding phenomenon and processing is good, then cooperated with the corresponding protection plate, and improved the shell, combined into a new type of double-cavity vertical shallow-basin type composite plate seed-metering device, defined the model as 2B-JP-FP-01.