Study On Mechanical Characteristics And Pulling Parts Harvest Of Carrots Tassel

The planting area and total output of carrots in China remains stable forefront of the world's most.Carrot planting scale increased substantially in recent years,while the carrot harvest mechanization degree is very low.At present,the main harvest way of carrot harvester is the disc cutting type and pull type.The disc cutting type carrots harvester has high efficiency,but complicated structure,poor reliability.The disc cutter is easily worn out and the damage rate of carrot is high.Pull type carrot harvester which is suitable for field operation has simple structure,high reliability,but the pull rod is easy to scratch the carrot,and the consistency of the harvest needs to be improved.Aiming at the problems above,in order to improve the efficiency of pull type carrot harvest device,this paper focused on the mechanical properties of carrots,established the mathematical model and test bed of the pull type carrot harvest device,improved the kinetic curve of pull rod in combining the theory and experiment,put forward and designed the non-circular gear drive pulling type carrot harvest device.The main content of this paper is as follows:1)Carrying out the carrots tassel mechanical characteristics test,we draw some significant conclusions.In order to avoid clamping force is too small to cause carrot tassel slide and clamping force is too large to pinch off carrot tassel,when we use flexible conveyor belt clamp carrots,the clamping force should be between 300 N and 500 N.Meanwhile,pulling force con not be less than 300 N and pull rod speed needs to be maintained in 400mm/min that can make sure carrot tassel and fruit can be separated completely.2)The kinematics model of the Pull type harvest device was established,and the kinematics analysis software was compiled in MATLAB.By using pulling type carrot harvest kinematics analysis software,the influence of related parameters on the pull rod kinematics to curve of the pull type carrot harvest device was known.3)We established the servo motor drive test bed of the pull type carrot harvest device,and got the best parameters of separation efficiency under the test of carrots tassel and fruit separation on the test-bed.Furthermore,we optimized the kinematics curve of the pull rod,put forward the ideal kinematics curve and designed the synchronous pulling type carrot harvest device according to ideal kinematics curve driven by non-circular gear.4)Based on UG three-dimensional modeling software,the three-dimensional model of the non-circular gear drive pulling type carrot harvest device were established,and the virtual assembly was conducted.Then virtual prototype was imported to UG motion simulation module of the kinematics simulation analysis and the kinetic curve of pull rod was output.The conclusion obtained by simulation in UG was highly with the one obtain by theoretical calculation,which verified the feasibility of the modle of non-circular gear drive pulling type carrot harvest device.