Design And Experimental Study Of Electric Self-propelled Ground Jujube Harvester By Cleaning And Collecting

Xinjiang is the production of high quality jujube,in order to improve the capacity,the pattern of dwarf and close planting has become the main planting patterns of jujube.Before the harvest of jujube,according to the agronomic requirements,the jujube harvest time was delayed artficially for improving the quality of jujube.Most of jujube keep on the jujube tree branches and the natural drying process of jujube was completed on the tree branches.However,this way has led to more than a third of jujube from branches fell in the jujube field ground before harvesr.The ground jujube were formed.It is difficult to harvest jujube by jujube harvest machinery.So the harvest of jujube mainly rely on manual picking up.In order to solve the harvest question of Xinjiang dwarf and close planting jujube,self-propelled jujube harvester was designed and processed.The jujube harvester was utilized with fire fan.The key parts of jujube harvester were emphatically designed and theoretical analyzed.And it was also finite element analyzed.The jujube harvest experiments of trial productionprototype were conducted and the reliability of jujube harverst machinery was verified.The finish research work are as follows:(1)Mechanical properties of jun-jujube and hui-jujube in crisp ripe period were measured,and the two jujubes is primary planting varieties in Xinjiang.And the mechanical properties of jun-jujube and hui-jujube anti-compression are anisotropic.The minimum strain energy of jun-jujube under vertical and horizontal compression are 164.384 m J and 368.126 m J,respectively.The minimum strain energy of hui-jujube under vertical and horizontal compression are 118.843 m J and 230.858 m J,respectively.The young's modulus of jun-jujube under vertical and horizontal compression are 0.30 MPa and 0.33 MPa,respectively.The young's modulus of hui-jujube under vertical and horizontal compression are 0.17 MPa and 0.29 MPa,respectively.The density and average hardness of jun-jujube are 727.59kg/m3 and 12.26kgf/cm2,respectively.The density and average hardness of hui-jujube are 851.24kg/m3 and 13.89kgf/cm2,respectively.(2)The working mechanism,design scheme and design parameter of the jujube harvester were determined by combining the jujube orchards research situation and mechanized harvesting jujube agronomic requirements of farmers.The key parts of cleaning device,copying shovel jujube device,the secondary transmission device,miscellaneous equipment,hydraulic equipment,electrical control system,transm-ission system were designed and analyzed.(3)Equivalent strain and stress diagrams of cleaning roller brush rack that was arranged with V-shaped are obtained in the finite element simulation by finite element analysis software,and the maximum deformation value is larger and the maximum equivalent stress is beyond the material allowed range.Deformation has significant effect on the cleaning operation,the design of rack is not reasonable.The indicators of improved cleaning brush roller meet the design requirements by finite element analysis.And the improved rack was analyzed by finite element structural dynamic analysis.Six order natural frequency of the rack was calculated by modal analysis.The six order natural frequency and vibration frequency of diesel engine and cleaning roller brush is obviously different.So the resonance phenomena would not generate.And the indicators of improved-rack meet the requirements of design,the improved-rack is reasonable.(4)The relationship between V-shape cleaning roller brush speed,harvester speed,V-shape cleaning roller brush opening-angle and harvest efficiency,pick up the net rate,damage rate were determined by signal factor experiments.That V-shape cleaning roller brush speed 140r/min,harvester speed 0.4m/s,cleaning roller brush opening-angle 90°are the optimal parameter combination and it was determined by orthogonal.At last,the harvest efficiency of jujube is 413kg/h,the picking up net rate of jujube is 93.6%,the damage rate of jujube is 2.1% were tested by harvest experiments.The indicators of harvester meets the design requirements.