| Cassava is a widely used economic crop,has been planted in large area,which has great influence on civil,energy industry and national defense technology,industry demand is huge.The harvest of cassava harvest mechanization has not yet been achieved,which restricts the development of the industry,with the urgent needs of national policies to support and new and renewable energy,the sustainable and rapid development of the cassava industry urgently cassava harvest mechanization.In the paper the dig pulling cassava harvester as the research object,in view of the problems existing in the present mining device,through structural design,mechanical model establishment and analysis,finite element analysis and so on,to mining of each component of the device were analyzed and trial and field experiments.The main research contents and conclusions are as follows:(1)Cassava biological characteristics and cultivation methods were investigated.Cassava tuber distribution width,growth depth,maximum diameter and length and other basic morphological characteristics were measured,which provide basic requirements for the structure design of mining equipment parameters.(2)According to the project of mining shovels,reference other root crops device structure mining,combining dig pulling harvest mechanism and soil compression failure theory and adhesion properties,the second order curved surface shovel and vibration combined shovel digging device and the depth limiting mechanism have been developed.The mining device has good working performance,and the depth limiting mechanism makes the digging device have stable tillage depth,and the working stability of the machine is enhanced.(3)The structure and parameters of the two order curved surface digging shovel is designed.Upper and lower grinding blade form the shovel penetrating performance better,second order the shovel body structure for mining shovel with good embedment and soil crushing performance,blade convex design reduced adhesion and resistance of soil.In order to simplify the mechanical characteristics of the two order shovel,the virtual shovel surface is introduced,which is convenient for structural parameter optimization.(4)According to the soil dynamics and physical parameters,the relationship between the shovel operation and soil,the soil stress model was established.Soil strength,adhesion,cohesion and friction force were analyzed,and the mathematical model of the traction resistance of the digging shovel was established.(5)Tractor linkage of excavation of influence of the angle of inclination of the shovel,and stroke of penetration and penetration angle relationship was studied,from the angle of the earth and into value of 10° best be determined.The relationship between the dip angle of the shovel surface and the time of the compressed soil was analyzed,and the performance of the crushed soil with the rake angle of 300° was the best.According to the influence of the combination of the first order and the inclination of the two order curved surface on the performance parameters of the digging shovel,the structure parameters of the two order curved surface shovel are ?1=10°,?2 =30°.Order a shovel surface height of h1=5cm when the optimal performance.The three-dimensional model of the SolidWorks mining device is designed,and the finite element analysis of ANSYS shows that the stress and strain are safe and reliable in the range of the material.(6)The working principle of vibration shovel is studied.The static analysis and modal analysis of the motion law curve and vibration shovel.To obtain the deformation and stress distribution,the natural frequencies of the vibration shovel,and provide the basis for adjusting and optimizing the vibration frequency.(7)Two order curved surface digging shovel was tested by trial production,and the field experiment was carried out.Experiments show that the mining shovel with good penetration and soil crushing performance,can form stable tillage depth,achieve the cassava harvest mining required. |
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