Design And Experimental Study Of Corn Straw Ridge-furrow-strip Mixed Burying And Returning Machine

The large yield of corn stalks is a resource of great value.In recent years,most of the straw has been burned,which not only causes waste of straw resources,but also causes environmental pollution.In order to solve this problem,the agricultural sector began to promote the straw returning technology,and there are many ways to return the straw to the field.The straw mixing technology can evenly stir the crushed straw into the soil,accelerate the decomposition rate of the straw,and increase the soil organic matter content.The soil forms a virtual and solid plough layer,which increases soil permeability and porosity,and can improve soil structure,preserve soil and regulate soil temperature,and reduce the use of chemical fertilizers and waste of straw resources.It is an important factor for comprehensive utilization of straw.In the corn ridge area of the northeast brown soil,the plough layer moves upwards year by year,the plough layer becomes shallower,and the soil cultivation environment is getting worse.To this end,the relevant experts proposed a method of returning straw to the field,which will be scattered in the field to collect and smash,and the smashed straw will be buried in the soil.The depth of the burial will be 150?200mm,forming a virtual and real soil ploughing.The layer is used to improve the fertility of the plow bottom soil,so that the straw resources can be effectively utilized.This topic comes from the public welfare industry(agriculture)research special fund project,research on the technical indicators of reasonable cultivation of dry land(201503116—09).Through the analysis and comparison of straw returning machines at home and abroad,combined with the agronomic experts in Northeast China put forward the technology of“reasonal tightness,inter-row looseness,soil and physical structure”,and design a corn straw ridge ditch strip.Returning to the field and conducting field trials.The main results in the research process are as follows:(1)Analyze the significance of the straw tillage mixed conservation tillage mode for the construction of reasonable tillage in dry land,summarize the development status of straw returning machine at home and abroad,understand the difference between domestic and foreign agricultural machinery and the domestic straw returning machine The shortcomings of the existence clarify the research content and technical route of the research topic.(2)By studying the literature and information of straw returning machine,the frame structure and the operation form of key components were determined according to the functional requirements of the machine,the design scheme of corn straw ridge,furrow and strip mixed planting machine was completed according to it's operation sequence.(3)Based on the analysis and research of the straw-brushing machine abroad,the kinematics analysis of the ridge-cleaning device was carried out,and the angle between the two elastic-tooth discs was determined,the working width and the range angle of the two elastic-tooth discs were calculated,and the area of the grass-brushing and the soil disturbance of the elastic-tooth discs on the ridge and furrow were analyzed and calculated.By analyzing the movement track of mixing knife,the rotary tillage ratio and pitch of cutting soil were determined,and the results met the agronomic requirements.The Archimedes spiral equation and the curve equation of the side cutting edge are obtained by parametric design of the mixing cutter's forward cutting edge and side cutting edge,The parameters of the burying cutter are determined.(4)According to the parameters of mixing knife,the three-dimensional model is built by using Solid Works software.By introducing the three-dimensional model into ANSYS for meshing and static analysis,the deformation contour map,equivalent stress contour map and equivalent strain contour map of mixing knife are obtained,which proves the rationality of mixing knife structure.EDEM is used to build simulation particle model and soil tank model.By setting the contact parameters,characteristic parameters of several model particles,the forward speed,speed and position relationship of ridge cleaning device and mixing device in the simulation analysis process,the working process of the key components of the whole machine is simulated and analyzed,and the ridge cleaning effect and mixing effect under different synchronization are obtained,which provides theoretical proof for the field test of the machine tool.(5)Through the analysis and study,the test factors and the test measurement index are determined.Design-Expert was used to design a three-factor,five-level,three-dimensional quadratic regression general rotary combination experiment,and the straw burial rate in the field was analyzed by regression.Combining with response surface analysis,regression equation fitting degree test and significance test were carried out.According to the response surface drawn by the fitting model,the effects of various factors and interaction on the burial rate were analyzed,and the order of influence of each factor on the burial rate of straw was obtained.The optimum conditions of the experiment were obtained by solving the regression equation:the forward speed of the machine was 1.25 m/s,the depth of straw embedding was17.5 cm,and the straw burial rate was 94.6%when the straw coverage was 0.93 kg/m~2.It meets the agricultural technical requirements of mixed burial and returning,and provides reference for the improvement of straw straw returning machine.