Design And Experimental Study Of Cone Hook Spoon Type Precise Metering Device For Mung Beans

In order to improve the level of mechanized planting of mung beans in China,this paper designed a conical hooked scoop precision metering device for mung beans with the goal of improving the efficiency of mung bean seeding and achieving the precision seeding of two mung beans per hole;Based on theoretical analysis,EDEM work simulation,single factor test,orthogonal rotation combination test and other methods,the optimal parameter combination of the conical hook spoon type mungbean precision metering device was determined;According to the optimal structure parameter combination,the conical hook-spoon precision metering device for mungbean was manufactured,and its working performance was verified by bench test and field test.The specific research content and conclusions are as follows:（1）Determination of discrete element simulation parameters.The seed density,triaxial size,Poisson’s ratio,coefficient of restitution of interspecific collision and coefficient of restitution of collision between mung bean and photosensitive resin plate of Bailu No.9 mung bean were measured;Measure the range of dynamic and static friction coefficients between mung bean species and mung bean photosensitive resin plate;Finalize the global variable parameters required for simulation.（2）Structural design and working process analysis of conical hook spoon type precision metering device for mung beans.A cone shaped hook spoon precision metering device for mung beans is designed based on the design concept of seed collection track,hook spoon carrying,and semi circular cross-section disturbance strip to promote seed filling,as well as the agronomic requirements for optimal sowing of two mung beans;It has been determined that the key component of the seed metering device,the hook spoon,adopts a 4mm round corner form on the back,and the radius of the semi circular cross-section seed disturbing strip is 1mm;At the same time,conduct motion analysis and theoretical analysis on the working process of the conical hook spoon type seed metering device,and obtain its influence law.（3）Simulation and experimental research on the working process of conical hook spoon type mung bean precision metering device.This chapter determines the factors and level of combined test through single factor test and theoretical analysis;By analyzing the variance table of orthogonal rotation combination test,it is concluded that the bottom length L₁ of trapezoidal groove,the radius R of the chamber,and the advance speed V₁ have significant effects on the optimal seeding rate and the rate of missed seeding;The structural parameters are optimized by the Design Expert software,and the optimal parameter combination is obtained by combining the boundary conditions:the trapezoidal groove bottom length is 4.7mm,the cavity radius is 5 mm,and the forward speed is 4 km/h;Under the condition of this parameter combination,the optimal sowing rate was 98.48%,and the missed sowing rate was0.19%.（4）Performance inspection of conical hook spoon type mung bean precision metering device.This chapter processes the cone hook spoon type mungbean precision metering device according to the optimal structure parameter combination of cone hook spoon type mungbean precision metering device determined previously,selects the white mungbean seed No.9 for speed gradient test,and selects three mungbean varieties Pearl No.2,Wan Lv No.2,and Zhong Lv No.8 for variety adaptability test of metering device,The working performance of cone hook spoon type mungbean precision metering device was tested by seed metering device performance test bench and field test method;The field test results showed that under the field operation speed of 4～8 km/h,the seeding success rate reached more than 87%,the missed seeding rate was less than 8%,and the variation coefficient of grain spacing was less than 20%,which met the requirements of the industry.