The Whole Machine Design And Simulation Test Of Key Components Of Panax Notoginseng Combined Harvester

Panax notoginseng is an authentic medicinal material in southwest China,with high medicinal and economic value.It is a key green ecological industry in Yunnan Province,but it also faces the problem of low machine yield,which seriously hindrance the industrialization process of Panax notoginseng.The research of Panax notoginseng harvesting machinery at home and abroad is mainly divided traction harvesting,the harvesting method is relatively single,and the adaptation to hills and mountains and agronomy needs to be improved.Joint mechanization research is necessary,therefore,this article on major r&d projects in Yunnan province plan"overcome notoginseng continuous cropping obstacle to building and application of technology system"the sub-project of notoginseng"overcome continuous cropping obstacles engineering facilities and machinery and equipment research and development"and national natural science fund"notoginseng harvest mechanization mining working mechanism and key technology research",Designed a Panax notoginseng combined harvester,the whole machine includes:killing seedling,excavating,conveying separation,chassis,collection and transmission five devices,as well as transmission,power,hydraulic adjustment three systems,and the key components of the simulation test.The specific research contents are as follows:（1）Summarize the research status of harvesting machinery at home and abroad,summarize the field research on Panax notoginseng planting agronomy,and determine the basic physical parameters of Panax notoginseng.The composition of planting soil was analyzed,and the soil particles of>5mm,2mm～5mm,1mm～2mm and≤1mm accounted for 21.93%,21.22%,20.57%and 36.28%.The soil texture was determined as cohesive soil,and the soil firmness was140.52k Pa～304.54k Pa.The water content and density of rhizome,stem and soil of Panax notoginseng were 76.81%,80.89%～86.13%,23.42%,1.11g/cm3,0.93-1.14 g/cm3,0.95g/cm3.Combined with measured physical parameters,through Solidworks software and reverse engineering means,establish three-dimensional model and discrete element simulation model,for the subsequent simulation test preparation;The mechanical properties of stem were tested,and the results showed that:Axial bearing strength of stem is greater than radial bearing strength,and tensile,shear and compression loads of stem range from 7.46mpa to 11.25mpa,0.72Mpa to2.25mpa and 6.45Mpa to 12.25mpa,which supplement the blank of mechanical properties of stem and provide reference for subsequent design and simulation of key components.（2）Conduct contact parameter calibration tests.The high speed photography test and discrete element simulation test were compared,the contact test results were fitted and analyzed,and the contact parameters were determined by quadratic regression orthogonal test.The collision recovery coefficient A₁=0.73,static friction coefficient A₂=0.335 and rolling friction coefficient A₃=0.0029.Coefficient of recovery of culm collision a₁=0.350,coefficient of static friction a₂=0.450,coefficient of rolling friction a₃=0.055;FTC texture tester and discrete element simulation were used to carry out mechanical properties comparison test.The results showed that the change trend of stem force in the bench test was consistent with that in the simulation test,which verified the accuracy of the contact parameters.（3）Complete the design and simulation study of the key components--seedling killing and digging device.According to the agronomic requirements,the working width of the whole machine was determined to be 1500mm,the linear speed of seedling killing was 1.2m/s～1.5m/s,and the adjustment range of seedling killing height was-100mm～100mm.The statics simulation test was carried out on the tool.The test results showed that the simulation load curve was consistent with the actual change,and the relative error was 17%with the measured data.The finger-like rubber belt was used in pairs to design the stem clamping and transmission part.In order to match the killing operation,the line speed of the clamping part was determined to be1.5m/s～2.25m/s,the line speed of the conveying part was determined to be 1.65m/s～2.7m/s,and the length of the clamping and transmission was 500mm.Based on previous studies,bionic shovel and plane shovel were designed to carry out statics and discrete element simulation comparison test.The statics simulation test showed that the bionic shovel had better load bearing capacity than plane shovel,and the two loads were 92.072MPa and 167.2MPa.Discrete element simulation test showed that:The mobility of roots and soil on the bionic shovel is better than that on the plane shovel.The resistance of the two is 1559.76N and 1929.32N,and the drag reduction rate of the bionic shovel is 19.15%.The experiment verified the structural advantages and drag reduction of the bionic shovel.（4）Complete the design of chassis,conveying separation,collection and transmission device.In order to adapt to the hilly chassis,the metal seismic crawling-type is selected.The forward and lateral bending moment of the whole machine is about M_z=8790.161N·m～19608.292N·m,M_c=6062.18N·m～13522.96N·m,the driving speed of the whole machine is 0.2m/s～0.5m/s,and the differential transmission mode is selected.Finger-like rubber lifting rod and two-stage separation were used to design the conveying separation device,and the lifting line speed was determined to be 0.36m/s～1.06m/s,and the range of transmission Angle was 15°～33°.Complete the design of collection and transmission device,combine the advantages of combined harvest and traditional harvest,control the positive and negative rotation of spline rubber wheel to adapt to different operation requirements.（5）Integrated analysis of transmission system,power system and hydraulic adjustment system of the whole machine,and completed the design of hydraulic system component diagram and basic component selection;The theoretical transmission power of the whole machine is calculated to b e 41.58k W～51.98k W,equivalent to the theoretical power needed by 56.55hp～70.69hp,which pr ovides a basis for the selection of power system.Virtual assembly of the whole machine,the thre e-dimensional size of the whole machine is 2842mm×1832mm×1436mm（length×width×heig ht）,the design of the whole machine meets the operation requirements and agronomic requireme nts of Panax notoginseng combined harvester.