Study on Vertical Disk Seed-metering Device of Using Gravity and Centrifugal Force to Fill Seeds
|School||Northeast Agricultural University|
|Course||Agricultural Mechanization Engineering|
|Keywords||Seed-metering device Gravity and centrifugal force Vertical disk Containmentprotecting seed-shield EDEM|
The topic selection of thesis is based on the National Natural Fund Project “The Innovationand Mechanism Research of High-speed Mechanical Soybean Precision Seeding-metering Device”,which based on the theory fall inside and increase outside (Item Number:51275086).The objectiveof this paper is to study on vertical-disk precision seed-metering device which makes use ofgravity and centrifugal force and it has a good performance in filling seed. Aim at providing newtechnology and theory support to promote the research of the high-speed operational capability ofmechanical precision seed-metering device.The paper makes a deep research of the vertical-disk precision seed-metering device whichmakes use of gravity and centrifugal force according to the all-around research route and principlethat combines the theoretic analysis and innovating design, test and virtual simulation.(1) Clear the key and direction of researchThrough widely consult relate technological materials, comprehensive consultant ofspecialists’ opinions, there are still many scientific problems to be solved in the design anddevelopment of mechanical precision seed-metering institutions. This paper thoroughly sums upthe experience from the former research of seed-metering device, refers to the technologicalcharacteristics of the present same machines both at home and abroad for reference, at the sametime, combines with the new requirements of modern mechanized operation, and further clears thekeys of the machine should lie on many aspects, such as improving filling performance, increasingmetering frequency and establishing related theory.(2) Innovation on seed-plate and seed-shieldUnder the comprehensive analysis and consideration of the quality about kinds ofrepresentative metering devices and seed-shield plate on the market, shallow basin verticalmetering device which makes use of gravity and centrifugal force and the seed-shield plate whichcan hold and protect the seed has been designed creatively. The problem of traditional vertical-diskprecision seed-metering device has been solved with the combination of the interaction, the gravityand centrifugal force in seeds, avoiding the phenomenon that the inner-ring seed-metering devicecan’t clear the seed when it is in limit speed. It has made a seed-shield plate which canaccommodate and protect seeds by designing a ring groove processing structure. This seed-shieldplate has made dual function that it not only protects the seeds like vertical-disk metering device,but also effectively overcomes the defects that the traditional seed-shield made to hurt seeds.(3) EDEM particle simulation research Because of the complex mechanics and a variety of morphological changes, EDEM particlesystem simulation technology and CATIA V5R20have been used to make virtual simulationresearch on the mechanical seeding-metering device. All-around configuration method is used toestablish the environment on the material with EDEM particle model and institution3D model. Bysetting global variable, establishing particle model, importing the geometry model, adding sportsattribute, defining of pellet plant, the movement process of the soybean seeds filling, clearing,protecting and metering has been simulated within the seed-metering device,and gets some relateddata like hole ratio and weight ratio.This method has fully considered some actual factors such asthe recovery and friction about the collisions between particles and particles, particles and walls,and the calculation about force.(4) Experimental research and establishment of regression model of the seed-metering deviceIn order to have a comprehensive research and discuss the right approach to improve andincrease the performance of vertical-disk precision seed-metering device which makes use ofgravity and centrifugal force, a test device that could thoroughly reflect major characters of theoriginal seed-metering device, adapt to factors of multiple-level adjustment, visualize the workingprogress, and joint well with test bed was designed. The device was studied on JPS-12test-bed,getting some performance indicators data as qualified index, leak seeding index, replay index.Then experiment was designed and data was processed with professional software Design Expert6（Copyright2000by Stat-Ease，Inc）、MATLAB. The grain particle mechanics model whenseed-metering was working, the regression model about the metering device performance metricschanging with relevant factors, the working principle of seed-metering device and the affectingregulation of the fundamental structure on seed-metering device performance are cleared, and agroup of the best parameters has been obtained after optimized.(5) Product design of new seed-metering deviceBased on the experiment and optimization analysis, it made the machine with characteristicsof vertical composite plat and clearing excrescent seeds by its gravitation as the seed-meteringdevice product design, after considering some technological factors such as the performance,structures and the coupling. Vertical-disk precision seed-metering device which composed of shell,sight glass, metering shaft, seed-shield which can hold and protect the seeds and the verticalcomposite seed-metering device which can use gravity and centrifugal force, has characteristicssuch as small lateral size, simple structure, easy to drive, good performance for seed filling,accurate, moderate price.