Chassis Design And Trafficability Model Test Of Self-Propelled Panax Notoginseng Combine Harvester

Panax Notoginseng is a famous Chinese herbal medicine with high medicinal value.In recent years,with the continuous improvement of people’s attention to health,the demand for Panax Notoginseng is also rising,Panax Notoginseng industry ushered in a period of rapid development.Panax Notoginseng planting land is usually located on the gentle slope,and Panax Notoginseng harvest has been completed by manual for a long time.High harvest cost,heavy work intensity and low efficiency greatly hinder the development of the industry,so Panax Notoginseng mechanized harvest problems need to be solved.Based on the above issues,this thesis designed a self-propelled Panax Notoginseng combine harvester with functions such as excavation,separation,transportation,and collection,targeting the working environment in the hilly and mountainous areas of Yunnan Province.This thesis focused on the design and research of the combine harvester chassis and power transmission system.This thesis relies on the project of "Innovation and Application of Special Cash Crop Intelligent Harvesting Technology and Equipment" of the "14th Five-Year Plan" national key research and development program,"Innovation and Application of Panax Notoginseng Combined Harvesting Technology and Intelligent Equipment(2022YFD2002004)",the chassis and power transmission system of the combined harvester were designed and calculated in detail.The field driving performance of the machine was analyzed.Specific research contents and conclusions are as follows::(1)Through field investigation of panax notoginseng planting base and reference to relevant literature,in-depth understanding of the agronomic norms and landform of the planting base was made,and the harvest width and total width of the chassis were determined to be 1500 mm.Combined with previous research results of the team,the overall scheme of self-propelled panax notoginseng combined harvester was proposed and parameters related to the chassis driving performance were determined.The performance of straight steering,climbing and obstacle crossing of the combine was analyzed theoretically,and the influencing factors were obtained.(2)Completed the design and calculation of all parts of the chassis.The overall layout of the harvester chassis was analyzed,and the "four-wheel belt" of the track chassis was designed and calculated.The finite element strength analysis of the frame was completed,and the maximum stress was 324.05 MPa and the maximum deformation was 2.8mm,which meeted the design requirements.(3)Completed the design and calculation of the power transmission system.By analyzing and comparing the power values under different limit working conditions,the required engine power was 55 k W;Completed the walking transmission system design,mainly for the HST hydraulic system and mechanical transmission selection calculation;Completed the transmission system design of the working device,the hydraulic system especially the hydraulic motor and hydraulic cylinder selection calculation;Completed the design of other parts of the chassis,such as hydraulic valve,radiator,fuel tank and cab,and determined the control mode of the combine;The virtual assembly of combine harvester was completed and the 3D model of the whole machine was obtained.(4)The multi-body dynamics simulation analysis of the combine was completed based on Adams/ATV software.The simulation analysis conditions included running straight and turning,longitudinal slope and lateral slope simulation through variable slope at the second gear speed of 1m/s,and crossing ditch with variable width and climbing ridge with variable height at the first gear speed of 0.5m/s.The simulation results show that the combined harvester has smooth running and steering performance,and can pass through 30° longitudinal slope,20° transverse slope,350 mm high ridge and 600 mm wide ditch smoothly.(5)The model test verification of the driving performance of the chassis of the combine was completed.A 1:4 miniature platform model of the chassis of the harvester was designed by the method of dimensionality analysis of similarity theory.A 1:4simulated terrain was built by referring to the simulated terrain,and a driving performance model test was carried out by using the attitude sensor to record data.The experimental results show that: The model can successfully pass through 30° climbing,150 mm trench and 87.5mm ridge.The pitch Angle and corresponding angular velocity curve trend under the above three conditions are consistent with the simulation,and the amplitude change of the pitch Angle curve obtained by the two conditions is the same.The experimental error is mainly affected by the actual terrain flatness and soil evenness.The results show that the model test can verify the correctness of the simulation analysis results,and through the model prediction of prototype and simulation results,the design requirements of the driving performance of the combine harvester are satisfied.