| Plant protection work in the middle and late period of maize has always been a difficult point in the growing period of maize.At present,the main machinery for plant protection work in the middle and late period of maize include large self-propelled high-clearance plant protection machine and plant protection unmanned aerial vehicle.After wheat-jade rotation was carried out in Huang-Huai-Hai Plain,the straw returned to the field,which resulted in a large amount of straw covering on the surface and surface layers of soil,which made it difficult for plant protection machines to walk between rows in large height gaps,and the rate of crushed seedlings was high.In milking-ripe stage,maize plants have high density,serious coverage and shielding,narrow rows,and most of the diseases are concentrated under the leaves in the middle of the canopy.UAV spraying is difficult to penetrate the leaves,and it is difficult to achieve satisfactory effects in fog-drop deposition,uniformity and coverage rate,etc.,and the comprehensive control effect is not good.Based on corn middle sealing line after artificial labor intensity,low efficiency,applying pesticide traditional plant protection machine spray penetrability is poor,and narrow spacing walk under the machine problem such as poor stability,in combination with maize agronomic crop canopy and pest control requirements,on the basis of self propelled crawler chassis,we design a Y type nozzle self-propelled row of corn and spray machine,can satisfy the 600 mm below the narrow spacing maize canopy below middle leaves space requirements for prevention and control of plant diseases and insect pests.The atomization characteristics and the effectiveness of application in field operation were studied.The specific research contents are as follows:(1)The problems of maize plant protection in the middle and late stage and the status quo of maize plant protection machinery at home and abroad were summarized,and the research objectives and contents of Y-nozzle self-propelled maize interrow sprayer were expounded.(2)Determine the structure and performance parameters of the whole machine,elaborate the working principle of the whole machine,design the spray system,analyze the influencing factors affecting the atomization effect,and introduce the relevant parameters and standards for evaluating the atomization quality of droplets.(3)The Y-nozzle pulse smoke machine was modeled and the simulation model was determined.Fluent software was used to study the influence of Y-nozzle Angle,the position of liquid nozzle on the nozzle and other factors on the atomization performance.(4)analyze the atomization characteristics of smoke machine,combined with the influence factors of affect the atomization effect in the orthogonal experiment,the optimal parameters combination,the optimal parameter combination for the optimum design scheme for Y type nozzle Angle 60 °,the position of the liquid in the nozzle mouth,for the combustion chamber at the end of 0.61 m distance place,smoke machine nozzle distance by the liquid surface is2.37 m.(5)The prototype was tri-produced in the mechanical and electrical engineering park of Anhui Agricultural University,and the field experiment was carried out in the maize planting base of Anhui Agricultural University in Suzhou,Anhui.The effective spraying width was determined to be 6-8 m when the operating speed was 0.6-1.1 m/s and the spray drop coverage rate was greater than 10%.When the speed is 1.5m /s,the spray drop coverage rate gradually decreases,and the effective spraying width for the spray drop coverage rate greater than 10% is less than 4 m,which can guarantee the quality of 10 rows of crops in a single time. |
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