| As an important food,medicinal,and economic crop in China,peanut cultivation and production hold significant significance for human society and economic development.Currently,the mechanization level of peanut production in China is not high.According to statistics,from 2015 to 2020,the comprehensive mechanization rate of peanut production increased from 51% to 64%,which is far lower than wheat(97%)and soybean(90%).Additionally,most peanut picking and harvesting machines face issues with conveyor blockages,which severely impact peanut harvesting efficiency and restrict the mechanization development of peanut harvesting.In this study,various research methods,including theoretical analysis,discrete element simulation analysis,orthogonal experimental design,discrete element and multibody dynamics coupling simulation technology,and high-speed photography technology,were employed to optimize the design and conduct experimental research on the feeding and conveying device of the peanut picking and harvesting machine.Through field prototype testing,the performance of the feeding and conveying device was evaluated,and the results met the quality requirements for peanut picking and harvesting machine operation.The specific research contents conducted in this study are as follows:(1)Field research was conducted on peanut cultivation practices,and the current status of peanut harvesting machinery research at home and abroad was summarized.Experimental measurements were performed to determine the basic physical parameters of peanut seedlings and fruits,including moisture content,weight,three-axis dimensions of pods,and peanut seedling dimensions.Based on the measured physical parameters,three-dimensional models of peanut plants and discrete element simulation models were established using Solidworks and EDEM software.Mechanical performance tests were conducted on different parts of peanut plants and calibrated.Test results demonstrated that the axial bearing strength of the stem exceeded the radial bearing strength.(2)Optimization Design of Key Structure and Parameters for the Feeding and Conveying Device.In this study,a three-dimensional model of the peanut picking and harvesting machine was created using Solidworks 2020,with a focus on the design of the feeding and conveying device.The operational parameters were determined based on the working principles and agronomic requirements.Through the process of dynamic analysis,it was deduced that the transportation performance of peanut plants in the auger is determined by the material feeding amount and auger rotation speed when the structural parameters of the feeding auger and the force values of the transmission device are fixed.The transportation performance of peanut plants in the bridge conveyor is determined by the spindle rotation speed of the bridge.An orthogonal experimental design was conducted using Design-Expert,and the factors were ranked as follows: auger feeding amount > feeding auger rotation speed > bridge spindle rotation speed.(3)Simulation Study of Key Components in the Feeding and Conveying Device.The chain rake of the conveying system was modeled using multi-body dynamics,and a three-dimensional model of the bridge chain transmission system was constructed.The RecurDyn software was used to establish a multi-body dynamics model of the bridge chain transmission system and conduct simulation experiments of the feeding and conveying device system.Design-Expert was utilized for orthogonal experimental design and data analysis.The transportation time was set as the evaluation index,and the objective was to minimize the response value.The optimal operating parameters were obtained.A prototype was manufactured and field tests were conducted.The experimental results confirmed that the auger and bridge of the machine were not prone to blockage,and the conveying efficiency was high.The overall design of the machine met the operational and agronomic requirements of peanut picking and harvesting. |
PDF Full Text Request