Design Of Ditching And Soil Covering Device For Corn Straw Direct Injection Returning Machine

Straw returning to field is the most direct and effective way of straw comprehensive utilization.Straw mulching can effectively fertilize soil and partially replace the application of nitrogen,phosphorus and potassium fertilizer.Aiming at the problems of large corn planting area,large straw output and short processing time in northeast China,a field investigation was carried out in Fumeng County,liaoning province.Based on literature review,field investigation,theoretical analysis and experimental research,this paper designs and selects the ditching and overlaying device of the corn straw direct injection returning machine.The following contents were studied in this paper:(1)The overall scheme of direct injection returning machine for corn straw was determined.According to the agronomic requirements,the direct injection shovel was put forward to operate in the way of "enriching and returning the field",and the structure and working principle of the direct injection returning machine for corn straw were introduced.The transmission system of direct injection corn straw returner is designed and the transmission ratio is calculated.The power required by the suspension and the power consumed by the ditching operation of the tractor are calculated respectively to determine the minimum power required by the operation of the straw returner.(2)In accordance with the requirements of agronomy and design,the direct injection shovel parts for ditching operation were designed theoretically,and two schemes of direct injection shovel structures were designed respectively.The theoretical dimensions of hollow spatulas were obtained through the design of the groove section of soil after the direct spatulas.The optimum velocity and Angle of soil penetration of direct injection shovel are obtained by analyzing the stress of soil and shovel tip.Three different schemes of soil covering device were designed.By comparing the effect of soil covering,the disc soil covering device was selected as the best scheme.(3)Modeling and assembly of direct injection shovels are performed with Solidworks software.The finite element analysis of direct injection shovel was carried out with ANSYS software.By simulating the working condition of direct injection shovel of the two schemes,the change of resistance of direct injection shovel with time,the condition of gully section and backsoil are analyzed,and the best scheme of direct injection shovel is determined according to the actual working condition.By analyzing the static force of direct injection shovel,the stress situation of the vulnerable parts is obtained,which is convenient for maintenance.The sixth order mode of direct injection shovel is obtained by modal analysis.(4)According to the national standard agronomic requirements,the ditching stability of direct injection shovel was determined by field experiments.The results showed that the trench depth reached 32 cm.The width of ditch surface was 31 cm,the width of ditch bottom was 6cm,and the variation coefficient of direct injection ditch depth was 3.8%.The stability of ditching depth was 96.2%.Direct injection shovel depth reaches 39cm;The depth stability of deep pine is 98% and the straw returning rate is 94.6%.The direct injection shovel operation meets the national deep pine standard and meets the design requirements.