Theoretical And Experimental Research Of Tobacco Stalks And Roots Clearing Machine

This paper focused on the problem of tobacco stalks and roots clearing in the hilly mountain area of Fujian province and especially focused on the issues that need to be resolved in the field of tobacco cultivation such as the mechanized clearing of tobacco stalks,root residues,and root and soil separation difficulties,analyzed the physical characteristics of tobacco field soil and tobacco at harvest.Based on that,researched the mechanism of the key components of tobacco stalks and roots clearing,studied and broken through the common problems in the mechanized production of tobacco stalks and roots clearing,combined with agricultural machinery and agronomy,developed and optimized new equipment by the simulation and experiment,enhanced the overall technology level of mechanization of tobacco stalks and roots clearing.The main research contents were as follows:(1)Researched on physical characteristics of tobacco soil and tobacco at harvest.Measured the parameters of tobacco field soil at harvest,it was found that the moisture content,bulk density and firmness of the soil increased with the depth of soil infiltration.Analyzed the shape characteristics of tobacco stalks and roots at harvest,obtained the regressin model of tobacco stalk bark thickness ratio and the trend of tobacco stalk morphology.At the same time,it was found that the tobacco roots were mainly distributed in the 0-200mm soil layer at thevertical direction,especially in the 0-150mm.Carried out the mechanical tests of the cutting and bending of tobacco stalks,the stretching and cutting of tobacco roots at harvest,which provided the basis for further research and development of tobacco stalks and roots clearing machine.(2)Design overall scheme and analysis of the mechanism of the key components of tobacco stalks and roots clearing machine.Determined the overall scheme of tobacco stalks and roots clearing machine by analyzing the main types and characteristics of the existing key components of tobacco stalks and roots clearing machine.Analyzed the trajectory of the end point of the stalk knife roller by establishing the coordinate system,and performed the force analysis on the different types of the roller spike-tooth to get the best form was forward bending.Performed the tobacco stalks of the initial bending moment analysis,the throwing out condition analysis,the movement analysis of the throwing process and the force analysis of the throwing process,put forward the condition of tobacco stalks normally thrown form the rear of the unit:the horizontal displacement of tobacco stalk thrown toward to the rear of the unit needed to greater than the length of tobacco stalk.At the same time,the horizontal displacement of tobacco stalk which currently thrown toward to the rear of the unit needed to greater than or equal to the height of the current tobacco root-soil complex before the knife roller reached the next tobacco plant.Analyzed the connecting mechanism of connecting the main engine and the machine tool with the chain transmission power,and obtained the condition of the chain transfered stably and reliably.(3)Simulation and soil bin test of key components of tobacco stalks and roots clearing machine.Simulated the trajectory of knife roller end point and the tobacco stalk thrown process by Adams simulation software.Performed the modal analysis of the knife roller in the prestressed and non-prestressed state by ANSYS Workbench simulation software.It was found that the knife roller would not produce resonance at work.Carried out the soil bin test,the root soil removal rate and root loss rate of the stalk were used as test indicators,the quadratic regression orthogonal rotated combination design was carried out on 3 factors,the rotation speed of the clearing roller,the baffle clearance and the walking speed to get the regression equation of the root soil removal rate and root loss rate,and performed the response surface analysis and multi-objective parameter optimization to get the best working parameters that were the travel speed of 4km/h and the knife roller speed of 450r/min,the baffle clearance was 150mm,and it was finally verified.(4)Whole machine design and field experiment of tobacco stalks and roots clearing machine.Disigned the whole machine of tobacco stalks and roots clearing machine,especially designed the knife roller combinated with the forward bending spike-tooth and the spike-tooth seat to get better clearing effect.Through the field experiment of tobacco stalks and roots clearing machine,when the machine operated at the best working parameters,the root soil removal rate was 95.23%,the root loss rate was 5.86%,the clearing leakage rate was 1.63%,and the stalk coverage rate was 0%,the stalk stump breakage rate was 2.44%,and the clearing effect was well.