Study On Optimization Of Snapping Roller Based On Bionic Corn Ear Picking Device

In recent years,new requirements for corn harvester were put forward with the transformation of maize planting structure.A kind of bionic corn ear picking device was designed by our group.Compared with the traditional maize ear picking device,it has improved obviously.However,there still be some individual corn seeds damaged and the corn snapping roller is too heavy,the stability of the picking device is reduced.In order to solve the above problems,this research stablished corn model,simulated the spike picking process of bionic corn picking mechanism test bench,carried out the test bench picking test.And redesign a new type of ear picking roller suitable for the bionic maize ear picking mechanism.The main research work is summarized as follows:(1)A maize plant model was established,including appearance model and the mechanical model of the corn plant.For the appearance model of maize plant,this research supplemented the measurement test of corn stalk based on the experiment of experiments in the early stage,and the average length of spike stalk was 7.3cm,the standard deviation was 1.47 cm.The average diameter of the spike stalk is 9.9mm,the standard deviation is 1.67 cm.For the mechanical model of maize plant,Maize ear tension and maize ear bending test for high moisture corn were carried out,and maize ear tension and maize ear reverse tension test were carried out for low moisture corn.The regression equation of corresponding parameters between the spike stalk diameter of maize and the moisture of the spike stalk was obtained.(2)In this study,We completed the theoretical analysis of the contact force between the snapping roller and the corn cob,the corn cob dropping moment and the corn cob speed during the spike picking process based on the simulation of the picking process of the bionic corn picking device.Thought the simulation of cob picking of bionic corn picking device,a three factor and three level orthogonal test of the maximum contact force between the snapping roll and the corn cob was completed with the appearance parameter of the snapping roller as the dependent variable and the maximum contact force between the snapping roller and corn cob.The appearance parameters of three kinds of aluminum,nylon and rubber materials are determined,the groove depth is 40 mm,the groove width is 40 mm and the pitch of the spiral grooves on the surface of the snapping roller is 80 mm.And three sets of picking rollers are designed according to the most suitable parameters.(3)The optimal matching parameters of corn picking test rig with different material snapping roller were obtained,and the two parameters were compared,based on the simulation and experiment on the harvest of maize with different moisture content were carried out through bionic type of corn picking test stand with different material snapping rollers and the reliability of the simulation was verified.The maximum speed of field walking was obtained when different water content corn was harvested by different types of snapping rollers with different materials,based on simulated field experiments in the laboratory.From the above analysis,we get the following conclusion,for the bionic corn picking device,nylon roller is suitable for high moisture corn harvest in several rollers.The snapping roller speed is 12.92r/s?the chain transmission speed is 0.67m/s?The angle between the snapping roller and the clamping chain is 30.28°,The maximum moving speed of the suitable field is 4.19 m/s.rubber roller is suitable for low moisture corn harvest in several rollers.The snapping roller speed is 10.36r/s?the chain transmission speed is 1.2m/s?The angle between the snapping roller and the clamping chain is 50°,The maximum moving speed of the suitable field is 4.33 m/s.