Design And Experimental Research On The Grading And Packing Device Of Apple Combine Harvester

Harvesting is a key part of apple production.At present,the picking,grading and packing operations in apple harvesting are mainly completed by manual segmentation.The picking,transportation,sorting,and packing operations are complex,labor-intensive,inefficient,and costly,the combined harvesting of picking,grading,and packing operations is "inorganic and available".In response to this issue,this study designed grading and packing device on a spiral comb brush type apple harvester in the early stage,and created a combined apple harvester that can achieve integrated operation of apple picking,grading and packing when moving between rows in structured orchards.The main content and conclusions are as follows.(1)Overall design of the apple combine harvesterAccording to the technical concept of integrated picking,grading and packing operations for joint harvesting,a grading and packing device was added to the spiral comb brush type apple harvester,and the overall structure and working principle design of the apple harvester suitable for the "vertical wall type" apple cultivation mode was completed;The overall structural dimensions,matching power selection,and key device motion parameters of the entire machine have been determined.The entire machine is mainly composed of a spiral comb brush type apple picking device,a double-layer hole belt grading device,a buffer rotor packing device,a crank and rocker fruit box release device,and a chain fruit box conveying device.The machine can continuously complete apple picking and grading packing operations while moving in a structured orchard.(2)Key device designAccording to the apple grading standards,physical parameters such as the equatorial radius,height,and mass of apples were measured and statistically analyzed.The requirements for three-level grading based on the overall size of apples were determined,and a double-layer hole belt grading device was designed.The movement process of apples during hole belt grading was analyzed,indicating that the brush is the key factor affecting the grading effect;By comparing the advantages and disadvantages of packaging methods,a buffer rotor packaging device was designed.By analyzing the movement during the apple packaging process,the horizontal displacement of the apple before entering the box after detachment from the buffer rotor was determined,providing a basis for fruit box positioning and chain fruit box motion control;Based on the structural characteristics of the fruit box,a crank rocker fruit box release device and a chain fruit box conveying device that can achieve continuous replacement of the fruit box were designed.By analyzing the motion of the crank rocker mechanism in the fruit box release device,the structural and motion parameters of the crank rocker mechanism were determined,providing a basis for controlling the release and conveying motion of the fruit box;A control system for a graded packing device was developed using Arduino as the main controller.The system uses apple packing sensors to obtain apple position information,and a stepper motor to execute motion requirements,achieving precise control of grading,packing,and fruit box replacement;The frame structure was designed and finite element analysis was conducted,and the maximum stress of the frame was found to be 1.8432 MPa,which is much lower than the maximum yield strength of Q235 material,verifying the rationality of the frame design.(3)Simulation analysis of the working performance of grading and packing devicePerform Recur Dyn-EDEM joint simulation analysis on the performance of the grading and packing device.Complete the generation of moving components,addition of movements,basic physical parameter settings,and generation of wall files with setting information in Recur Dyn software for the grading packing device;Import the wall file into EDEM,complete the parameter settings for particles and particle factories in EDEM,and establish a joint simulation environment.Single factor experiments were conducted using fruit flow rates of 1,2,and 4 per second,upper layer pore belt speeds of 50 mm/s,100 mm/s,200 mm/s,and lower layer pore belt speeds of 60 mm/s,140 mm/s,and 220 mm/s as experimental factors.Grading rate and packing rate were used as evaluation indicators for simulation experiments.The simulation experiment shows that fruit flow rate,upper layer and lower layer hole belt speed have a significant impact on grading rate,but have no significant impact on packing rate.(4)Trial production and experiment of apple joint harvesterAccording to the overall design scheme of the apple harvester,a prototype of an integrated apple harvesting and grading box control system was developed using the spiral comb brush apple harvesting device designed in the early stage of the project.The double layer hole belt grading device,buffer rotor packing device,crank rocker fruit box release device,chain fruit box conveying device,and grading box control system were added in this study.Based on theoretical analysis and simulation experiments,an orthogonal experiment was designed with apple grading rate,damage rate,and packing rate as experimental indicators,and fruit flow rate,upper and lower hole belt speed as experimental influencing factors.Under the parameters of fruit flow rate of 1-3 piece/s,upper layer pore belt speed of 50-150 mm/s,and lower layer pore belt speed of 60-200 mm/s,corresponding experiments were completed.The experimental results showed that the significant ranking of the effects on grading rate,packing rate,and damage rate was fruit flow rate,upper layer pore belt speed,and lower layer pore belt speed.The optimal working parameter combination for the graded packing device has been preliminarily determined as the upper layer hole belt speed of 100 mm/s,the lower layer hole belt speed of 140 mm/s,and the fruit flow rate of 1 piece/s.The whole machine is running and the grading and packing effect is tested with optimal working parameters.The test results show that the grading rate is 93.3%,the packing rate is 100%,and the damage rate is 6.67%,which basically meets the performance design requirements.