Design And Experiment Of Feeding Device Of Hairy Vetch Harvester

As one of the important crops in traditional agriculture in China,green manure has many functions,such as improving and fertilizing soil,reducing soil erosion,preventing and controlling diseases and insect pests,and increasing crop yield.As a typical leguminous green manurer,the cropping area of hairy vetch has been increasing year by year.At present,manual operation is the main method in China,and the mechanization level is relatively lower,which limits the enthusiasm of farmers to establishing in large scale.In this paper,the structural parameters and optimal working parameters of the feeding device are determined by means of comprehensive mechanical property test,design analysis of key components,numerical simulation,multi-objective optimization and field performance test,and its working performance is verified,so as to meet the design requirements of effective feeding and anti-winding of the device.The main research contents are as follows:(1)Mechanical properties experiment of the stem of hairy vetch.Turkmen hairy vetches are selected as subjects,the mechanical model of stem is established and the material characteristic parameters of stem is tested.The failure stress and elastic modulus of the stem under radial compression,axial tension and radial bending are obtained.(2)Design on the feeding device of the hairy vetch harvester.A feeding device for an antiwinding hairy vetch harvester is designed,which is fitted with the self-propelled hairy vetch harvester.The overall structure design and working principle are described in detail.And the structure design and parameter analysis of the key parts of cutting device and the vertical drum are also carried out.Its main design content is as follow: a rotary cutter with double disc rotary mower is designed,and adopted unsupported cutting method to improve working efficiency and reduce cutting resistance,The minimum rate at which the stems of hairy vetch can be effectively cut is 40m/s;The type of the blade is a double-blade torsion cutter with a thickness of 4mm and a torsion angle of 5°.By analyzing the motion track of the blade,it is determined that rotational speed of the blade is 1122r/min and each disc is equipped with three blades.For the design of vertical drum,the type of which is determined to be conical vertical drum.In order to ensure effective delivery of the stem,the maximum linear speed of the vertical drum is determined to be 27m/s,the diameter of the bottom surface of the drum is 280 mm,the other one is 220 mm,and the height of the drum is 300 mm.The steel plates welded around the drum’s surface are triangular in shape,the surface of which is curved and the arrangement mode is linear.(3)Performance optimization test of numerical simulation of feeding device based on Rocky.In order to explore the optimal working parameter combination of key components in the feeding device and improve the operation quality of the feeding device,the Rocky is used to simulate the feeding link of hairy vetch’s stems,and the discrete element interaction model between the feeding device and the stems is established to analyze the motion state of the stems in the device.The quadratic orthogonal rotational combination design with three factors is combined with virtual simulation technology,and the revolving speed of the vertical drum,the forward speed of the machine and the revolving speed of the spiral conveyor are taken as the experimental factors,and the loss rate of stems is taken as the experimental index.The designexpert V8.0.6.1 software is used for data processing,The simulation results show that when the speed of drum is 1037.5r/min,the forward speed of the machine is 2.76m/s,and the speed of spiral conveyor is 348.88r/min,the loss rate of stems is the lowest,that is,That is,the feeding performance of the feeding device is optimal,the loss rate is 2.38%.(4)Field performance experiment of the feeding device of hairy vetch harvester.Based on the self-propelled hairy vetch harvester,the field performance experiment of the feeding device is carried out with the simulated optimal working parameters,and the performance indexes of the feeding device are tested according to the national standard.The results of the field performance experiment show that all the test indicators meet the national standard requirements.The actual cutting width is 1.66 m,the stubble height is 6.41 mm,the surpassing stubble rate is 0.45%,and the missing cutting rate is 0.20% and stem loss rate was 3.00%,which verified the rationality of the design of feeding device.