Design And Test Of Successive Compaction Device Of Tobacco Ridging,Fertilization And Compaction Machine

Tobacco is one of the main economic crops in China which is mostly cultivated in ridges.The quality of ridges directly affects the growth of crops and ultimately the yield of tobacco leaves.At present,most of the tobacco ridge preparation machines are small agricultural machinery with single operation function,and the machines are repeatedly dropped to the ground,which cause soil compaction easily;and most of the ridge preparation devices are extruded after ridge formation,and the formed ridge body is exposed to wind and rain.After natural settlement,the ridge body is prone to collapse,which is not conducive to the growth of tobacco seedlings and brings inconvenience to subsequent operations.In this paper,on the basis of consulting a large number of domestic and foreign literatures about ridge preparation machinery,combined with tobacco ridge agronomy,a step-by-step compaction device for tobacco ridge fertilization machine was designed,and its key components were designed and analyzed,and the simulation analysis and performance test were carried out.The main research contents of this paper included the following five aspects:(1)Soil physical properties were studied,soil compression tests were carried out under soil conditions suitable for tobacco root growth,and soil physical properties were determined to provide data support for subsequent institutional design and experimental research.The measured soil bulk density was 1.015 g/cm3,the water content was 17.58 %,and the soil firmness was 38 k Pa ~ 59 k Pa.The soil compression test shows that when the soil subsidence is less than or equal to 25 mm,the soil firmness meets the agronomic requirements,which provides data support for subsequent mechanism design and experimental research.(2)Based on the discrete element method,the interaction model between the working parts of the machine tool and the soil was established,and the EDEM software was used to simulate and analyze the step-by-step compaction device of the tobacco ridge and fertilizer machine.The simulation results showed that the soil particles showed wave motion under the action of the step-by-step compaction device.Design Expert software was used to design three-factor and threelevel orthogonal test to study the effect of compression plate compression and forward speed of machine on working resistance.The optimal combination was as follows: the compression amount of the pressing plate was 18.8 mm,the compression amount of the pressing roller was 6.2 mm,the forward speed of the machine was 0.7 m/s,and the working resistance was 7303.26 N.(3)Based on the discrete element method,the interaction model between the working parts of the machine tool and the soil was established,and the EDEM software was used to simulate and analyze the step-by-step compaction device of the tobacco ridge and fertilizer machine.Thesimulation results showed that the soil particles appear under the action of the step-by-stepcompaction device Wave motion.Design Expert software was used to design three-factor andthree-level orthogonal test to study the effect of compression plate compression and forward speedof machine on working resistance.(4)After the ridge structure was optimized,the key parameters of the device can meet the requirements of 55 k Pa ~ 85 k Pa.The simulation results showed that the stability of the device can meet the requirements of the test-bed.Based on the above experiments,field experiments were carried out.The results showed that the ridge size met the agronomic requirements,the coefficient of variation of each size was less than 3 %,the ridge formation uniformity was good,and the ridge anti collapse ability was strong.