Optimal Design Of Trench Opening And Soil Covering Device Of Sand Soil Continuous Trenching And Tree Planting Machine

Afforestation is an effective means to solve the problem of large-scale desertification in Xinjiang.Aiming at this problem,this thesis designs a continuous trenching and covering tree planting machine for sandy soil to adapt to the desertification soil in southern Xinjiang.The intrinsic parameters of sandy soil and the agronomic requirements of tree planting in southern Xinjiang were studied,and the scheme of tree planting machine was determined;The kinematics analysis of the continuous trenching and soil covering operation process of the tree planting machine is carried out,the continuous trenching and soil covering device and other parts of the tree planting machine are designed,the stress of the trenching and soil covering device is analyzed,and the influence of the structural parameters and working parameters of the trenching device on the trenching resistance is studied;The discrete element contact parameters of sandy soil in southern Xinjiang are calibrated,and the operation process of ditching and covering device is simulated based on the discrete element method,so as to optimize the surface of rotary tillage broken soil plow with the goal of reducing resistance;Finally,it is verified by field experiment.The designed sand soil continuous trenching and covering tree planting machine meets the requirements of large-area and efficient tree planting in desertification soil,provides a theoretical basis for the design and parameter selection of continuous trenching and covering device,and is of great significance to improve the natural environment of desertification area in Xinjiang.The main research contents are as follows:(1)Determination of the complete machine scheme: in order to adapt the work of the tree planting machine to the sandy soil in southern Xinjiang,this thesis makes a field investigation on the desertification soil in southern Xinjiang,determines the intrinsic parameters of the soil,analyzes the agronomic and technical requirements and other parameters of the tree planting machine according to the planting mode of desertification control tree species,and designs the complete machine scheme of segmented continuous trenching and soil covering with one-time rotary tillage and two-time ploughing according to the agronomic and technical requirements.(2)Theoretical analysis of ditching and soil covering device: Aiming at the problems of large ditching depth and large resistance in continuous ditching operation,the kinematics of rotary tillage operation process is analyzed,the segmented continuous ditching device,continuous soil covering device and other parts are designed,and the stress of rotary tillage machete and soil breaking plough of rotary tillage ditching device in one ditching process is analyzed,Determine the structural parameters and working parameters that affect the trenching resistance in the process of trenching operation.(3)Optimization Research on trenching and soil covering device: in order to improve the reliability of structural design,according to the stacking angle and sliding angle reflecting the contact performance of sandy soil in southern Xinjiang and 65 Mn plow,the discrete element contact parameters of soil are calibrated by using multiple statistical regression theory through simulation and experimental comparison.After obtaining the discrete element parameters of sandy soil in southern Xinjiang,the soil model is established according to the working size of the trenching and covering device of the tree planter.Taking the three structural parameters of the plow surface(soil cutting angle,plowshare installation angle and vertical deflection angle of the plow surface of the broken soil plow)as the influencing factors and the trenching resistance as the response index,the influence of the structural parameters of the trenching device on the working resistance of the tree planter is studied,and the plow surface of the trenching device is optimized,The optimum combination of structural parameters is obtained: the soil cutting angle is 45 °,the installation angle is 22.5 °,and the vertical deflection angle is 0 °.After the optimization of structural parameters,the effects of two working parameters,forward speed and tillage depth,on the trenching resistance of the tree planter were studied.(4)Field test verification: after completing the design and optimization of the whole machine,the prototype trial production is completed,and the field test is carried out.The field test and simulation results are compared.The test is carried out at different forward speeds and ploughing depths.The test results show that the structure of the continuous trenching device and soil covering device of the tree planter meets the design objectives and can meet the requirements of efficient tree planting in desertification soil.