Design And Experimental Study Of Precision Seeding Device On Split Cotton Membrane

As the main cash crop in Xinjiang,cotton plays an important role in the production process.In order to reduce production costs and improve the efficiency of sowing,this paper designs a kind of planting material for cotton planted in Xinjiang based on the material characteristics of cotton seeds.Placed cotton membrane precision seeding device.This device is mainly composed of three parts: air suction type precision seed metering device that realizes precise seed filling and carrying,an orderly seeding tube,and a hole forming device that completes precision seeding on the film.The main components were designed and selected through structural design and theoretical analysis.The flow field distribution and flow field characteristics of the seed meter were analyzed using Fluent simulation software.The bench test was performed on the air-suction precision seed meter,and the effect on the seed meter The main factors of seeding performance were analyzed.Gas-solid coupling simulation was performed with EDEM discrete element software,and the test was compared with the bench test to verify the effectiveness of the simulation test.Secondly,the seed tube and the cavity forming device were experimentally studied.A separate test bed for precision seeding device on cotton membrane was established to study the parameters of different tree species.The main research contents include:1.Aiming at the characteristics and agronomic requirements of cotton planting in Xinjiang,a split cotton planting hole planting scheme is proposed,which is mainly composed of air suction seed metering device,seed tube and hole forming device.The structure design and theoretical analysis were established.The kinematics and dynamics model of the seeder's seeding process was constructed,the force and motion of the seed were analyzed,and the main factors affecting the seeding performance of the seeder's seeding process were obtained.2.Fluent software was used to analyze the flow field of the negative pressure air chamber of the seed metering roller.By analyzing the hollow shaft structure,the flow field distribution and velocity distribution of the hollow shaft flow channel of different structures and the negative pressure air chamber of the roller were selected,and the appropriate hollow was selected.Shaft structure.The change of the flow field inside the seed metering device was analyzed by changing the negative pressure of the negative pressure cavity of the seed metering device and the diameter of the suction hole of the drum.The negative pressure of the drum only affected the speed of the suction hole,but not the speed.Pressure distribution;the diameter of the suction hole has a certain effect on the air velocity at the suction hole.The larger the diameter of the suction hole,the smaller the air velocity at the suction hole.Conversely,the smaller the diameter of the suction hole,the greater the air velocity at the suction hole.3.The EDEM software was used to create a cotton seed particle model and a simplified model of the seeder.Cotton seed particles used the Bonding model and the API particle replacement method.The EDEM-Fluent coupling was used to simulate the seeding process of the seeder and select the best.Simulation parameters: drum speed 15.40 r/min,suction hole diameter 3.60 mm,negative pressure-5.00 kPa,the corresponding target parameters at this time are: qualified index 90%,missed broadcast index 3%,replay index 7%.4.By constructing the test bench of the air suction drum type seeder,the response surface method was used to establish the seeding pass index,leaking index and replay index of the air suction drum type seeder,and the rotation speed of the roller,suction hole diameter and negative pressure.Regression model.Determine the main influencing factors affecting the seeding performance index of the seed meter and the optimal parameter combination:drum speed 15.38 r/min,suction hole diameter 3.59 mm,negative pressure-5.04 kPa,the corresponding target parameters at this time are: qualified index 93.17 %,missed broadcast index 2.58%,replay index 4.25%.By comparing with the optimal simulation results,the feasibility of the EDEM-Fluent coupling method is verified,and it provides a basis for the optimization of the later seed metering device.5.The test bed for the precision seeding device on the split cotton membrane was set up to conduct a single factor test on each factor affecting the seeding performance of the split device.The optimal range of different seed tube materials,diameters,lengths and placement angles was performed.Selection.When the material of the seed tube is a PVC steel wire hose,the seeding performance is better than other materials.By selecting a suitable range of diameter,length and placement angle of the seed tube,the orthogonal test design is developed to determine the optimal parameter combination as: The diameter of the seed tube is 40 mm,the length of the seed tube is 350 mm,and the angle of the seed tube is 90 °.At this time,the seeding eligibility index is 86%,the missed seeding index is 11%,and the replaying index is3%.