Design And Experiment On V-groove Dialing Round Type Seed-guiding Device Of Maize Precision Planting Machine

Precision planting is the technique which uses machinery to accurately and quantitatively can sow seeds into the predetermined position.It is the most important application and extension technology in China agricultural production.Irregular movement caused by bouncing collision between seed and seed-guiding tube is one of the main reasons for uneven distribution of planting in the field,which affects the precision and stability of seed delivery by seed metering device,and results in the instant when seed falls into seed bed,it can not completely offset the relative speed difference with machine,so that the ideal performance index can not be reached during field operation.In order to improve the uniformity and stability of seed-guiding process,a V-groove dialing round type seed-guiding device was designed.This paper mainly studied six aspects parts,material properties measurement and analysis of maize seeds,design and analysis of V-groove dialing round type seed-guiding device,performance optimization experiment of numerical simulation of seed-guiding device based on EDEM,bench performance experiment of V-groove dialing round type seed-guiding device,configuration and experiment of maize precision device.The main contents were as follows:(1)Material properties measurement and analysis of maize seedsThree maize varieties of different grades suitable for extensive planting in Heilongjiang province were selected as the research objects,and the material characteristics were determined and analyzed.This section could provide a basic data and reliable reference for subsequent optimization design and its virtual simulation.(2)Design and analysis of V-groove dialing round type seed-guiding deviceA V-groove dialing round type seed-guiding device component matched with precision planter was designed.The optimal design of guiding curve,V-groove and dialing round of key components were conducted.The general structure and working principle of were described and analyzed.And then the matching electric control transmission system to drive flexible dialing wheel to rotate at the fixed working speed was developed,which can complete the dialing and sorting operation,ensure seeds enter guide groove smoothly.Effectively improve the operation quality and suitable range of seeding system.(3)Performance optimization experiment of numerical simulation of seed-guiding device based on EDEMThe optimization design of structural parameters of V-groove dialing round type seed-guidingdevice was conducted.The interaction model of machinery and maize was established using Distinct Element Method.This paper took scoop-type metering device as the seeding object and EDEM software was employed to simulate the seed-guiding process.And then the dynamic behaviors of maize were researched in the working conditions.Orthogonal simulation experiments were carried out based on numerical simulation technology with forward velocity,rotational speed,tangent angle as experimental factors and with qualified index and coefficient of variation as assessment consumption.The best combination was achieved.The simulation results showed that,as the forward speed was 7.69km/h,rotational speed was 29.47r/min,tangent angle was 46.10o,and the qualified index was 92.05%,the coefficient of variation was 8.00%,which could meet the requirements of maize precision planting.(4)Bench performance experiment of V-groove dialing round type seed-guiding deviceThe bench performance experiment was carried out to improve the seeding performance and obtain the best operation parameters.The high-speed photography experiment,comparison performance experiment and vibration adaptation experiment were carried out.The experimental results showed that,the majority of grains were slipping in a steady state in the tube and few irregular impacts and tumbling.The V-groove dialing round type seed-guiding device had better adaptability to different maize grains which could be used in conjunction with scoop-type,pickup finger-type and air suction-type precision seed metering device.Its qualified index was similar to that of unguided tube,and coefficient of variation was higher than that retractable plastic guide tube,curved guide tube and unguided tube.Under the normal operating conditions(vibration amplitude was 1~3mm and vibration frequency was 1~4Hz),the vibration amplitude and frequency had little effect on the homogeneity of the guided parts.(5)Configuration design and field experiment of maize precision deviceIn order to verify the actual operation performance of seed-guiding device in the field,a maize precision device was equipped to conduct field experiments.The results of field experiments show that,the qualified index of matching finger-clip metering device is more than80.32%,the multiples index is less than 11.46%,the missing index is less than 8.22%,and the coefficient of variation is less than 11.05%.The qualified index of matching spoon metering device is more than 81.96%,the multiples index is less than 10.83%,the missing index is less than7.21%,and the coefficient of variation is less than 10.68%.It is proved that the V-groove wheel-type seed guide parts designed can be applied to different types of mechanical precision metering devices,which satisfy the maize agronomy requirement.