Design And Experiment Of Centralized Belt Type Seed-Metering Device

Seeding machinery in crop production and promote the agricultural science and technology progress has the extremely important status and role,and the merits of the sowing quality determines the yield of crops.Agricultural machinery the operation efficiency is mainly decided by the metering device.At present,in order to improve the efficiency of the seed metering device adsorption,reducing separation resistance of single seed and generally adopt mechanical stirring device,mechanical vibration,pneumatic perturbation method to improve the fill ing performance.In order to remove excess seeds,seed cleaning component are usually installed inside the seed metering device.Seed cleaning component need precise installation position and corresponding installation space,which increased the complexity of the seed metering device internal structure.In order to simplify the whole seed metering device structure and reduce the cost,improve the efficiency of the seeding,suitable planting narrow line of agronomic requirements,we design a structure in open semi cylinder structure,the seeds in the gas pressure and under the action of centrifugal force type adsorption to the hole,the half cylinder structure under the action of friction with the row at the bottom of the seeds with upward movement,to reduce the seed with the relative speed between the type,improve the filling performance;The seed-cleaning vibration device is used to make the mold hole vibrate through the flexible seed row belt to disturb the extra absorbed seeds,reduce the separation resistance of single seed from the seed group,realize the seed cleaning process,improve the seed filling performance and improve the seeding quality.By exploring the influence of air pressure,operating speed and seed cleaning vibration frequency on its seed arrangement performance,the optimal working parameter combination was sought to provide reference for the design of cluster type seed arrangement device.This paper the main works and the research contents are as follows:(1)The design of the whole structure of seed metering deviceSeeds in order to simplify the whole seed metering device structure and reduce the cost,improve the efficiency of the seeding,suitable planting narrow line of agronomic requirements,use the half cylinder structure characteristics make the accumulation area of seed circulating to finish filling process,use with flexible features by kinds of vibration device to complete the cleaning process,complete a general structure design,determine the working principle and working process.(2)Analysis of the working process of the banding seed metering deviceCombined with the related theoretical knowledge of dynamics and kinematics,the kinematics analysis was carried out on the main seed filling and seed cleaning process of the seed distributor,and the seed dynamics related models of the two processes were constructed.The influence factors of seed adsorption were obtained.The motion trajectory of the dropped seeds in the seed cleaning process was analyzed.(3)Design and analysis of the key parts of the seed metering deviceThe key components such as seed cleaning vibration device,seed metering belt,sealing device,shell and frame are designed and analyzed,and the structural parameters and working parameters of related components are obtained,which ensure the overall good working performance of seed laying device.(4)Flow field analysis inside the seed metering deviceAnalysis of the flow field in the seed metering device.The finite element method was used to simplify the modeling of the flow field area inside the seeder,and the numerical simulation calculation of the flow field inside the seeder was carried out.The influence of different inlet positions and quantities on the pressure field inside the seeder was explored,and the distribution of the corresponding pressure and airflow velocity was obtained to determine the optimal inlet position and quantity.(5)Experimental study on seed metering deviceThe single factor test and multi-factor test were carried out on the main factors affecting the performance of centralized belt type seed metering device with JPS-12 seed metering device performance test bench.Through the single-factor test on the structural parameters and working parameters of the seed metering device,the influence rules of each factor on the performance of the seed metering device were determined.In multi-factor experiments,according to the national standard of GB6973-2005,the multi-factor experiment was carried out by the method of quadratic orthogonal rotation center combination of three factors and five levels.soybean seed Heinong 38 was selected as experimental material.Combining with extensive pre-experiment and theoretical analysis,the air pressure,working speed and clear vibration frequency as th e main influencing factors,and taking the seed qualified index,multiple index and missing index as the response index,the experimental research was carried out.The optimal combination of parameters were clear vibration frequency of 44.6 Hz,air pressure value of 4.4 k Pa and working speed of 10.5 km/h,and under the optimal combinations,the qualified index was 90.6 %,the multiple index was 2.0 %,and the missing index was 7.4 %,the verification test was repeated 5 times,the results was indicated that the actual test results were in agreement with the optimization results.This seed-metering device could meet the seeding requirements well.The results of the research provided a reference for the research of centralized precision seed-meter device.