Design And Experiment Of Pneumatic Groove-tooth Plate Precision Seed Metering Device For Rapeseed

Rapeseed is an important oil crop in Anhui Province.Production efficiency is increased through reasonable dense planting by machine direct seeding.Rapeseed precision seed metering device is the core component that regulates the seeding amount of the direct seeding machine,and the quality of planting density is determined by its working performance directly.In this paper,the combination of groove-tooth orientation seed churning device and suction hole adsorption technology was proposed to solve the problems of serious leakage and high wind pressure demand,because of poor seed filling effect during the high-speed seeding process of pneumatic plate type precision seed metering device for rapeseed.A kind of pneumatic groove-tooth plate type of groove-tooth precision seed metering device with assistant suction performance was designed;the particle dynamics theory,numerical analysis and high-speed camera technology and so on were used to study the assistant suction performance of groove-tooth.The main research conclusions include:According to the agronomic seeding requirements of rapeseed,the principle of device seed churning and assistant filling seeding was applied,so that the overall design plan of the new pneumatic plate type precision seed metering device for rapeseed was determined,,and the structure composition and working principle of the seed metering device were described,the structural parameters of the key components of the seed metering device were analyzed and determined in conjunction with the particle dynamics theory.The EDEM software was applied to carry out the numerical simulation research of assistant seed filling of plate type and groove-tooth structure.Taking the average kinetic energy of the seed-group and the sum of the average kinetic energy as the quantitative indicators,the results showed that: adding grooves and seed churning teeth on the traditional smooth plate could significantly increase the disturbance intensity of the seed-group.The order of the sum of the average kinetic energy at the same speed from large to small was groove-tooth plate,groove plate and smooth plate.The linear seed churning device with tooth thickness from 0.5 mm to 1.5 mm had good assistant seed filling effect,which helped to improve the fluidity of the seed and suppress the seed-group drag.The optimizing experiment of the seed plate type of the pneumatic plate precision seed metering device for rapeseed was carried out.The influence of the smooth plate,groove plate and groove-tooth plate on the suction performance was studied.The results showed that the leakage adsorption rate and absorption qualification rate of the groove-tooth plate were obviously better than the groove plate and the smooth plate.Under the operating speed of 10 to 110 r / min and negative pressure of 1.5 to 2.5 k Pa,the adsorption qualification rate not less than 92.0%,the sum of leakage adsorption rate and resorption rate was not more than 8.0%.The experiment on the assistant suction performance of groove-tooth was carried out.The optimal experiment of the type of seed churning device was carried out,and the influence of the thickness of the seed churning device,negative pressure and operating speed on the suction performance was studied with the optimized type of seed churning device as the object.The results showed that the assistant suction performance of the seed churning device with linear groove-tooth structure was better than that of the seed churning device with arc-shaped groove-tooth structure and the smooth plate without the seed churning device.The orthogonal test had optimized the suction performance of 1.0 mm in thickness.Under the condition that the thickness of the seed churning device was 1.0 mm,the negative pressure was 1500 ? 2500 Pa,and the operating speed was 2.6 ? 9.5 km / h,the adsorption qualification rate was not less than 96%,and the leakage absorption rate was not more than 4%.Carry out multi-channel seed arrangement performance test research.With a vortex air pump of 550 w and an operating speed of 2.6-8.6km /h,the seed discharge quantity of the four-row pneumatic trough tooth precision seed-discharging device presented an increasing trend with the increase of the operating speed.The coefficient of variation of the stability of the total displacement was no more than 1.5%,and the coefficient of variation of the consistency of the displacement of each row was no more than 3.5%,which met the requirements of reasonable close planting of rapeseed.