Development Of Stem Harvesting Device On Corn Harvester For Reaping Both Corn Stalk And Spike

As one of the main grain crops in China,corn’s planting area increases year by year.At the same time,stalk processing problems resulted by large-scale corn production have become increasingly prominent.Therefore,the corn straw processing technology will be the focus of corn harvester development in the future.At present,there are two main approaches of corn stalk processing,one is returning back to field,the other one is recycling and crushing for animal food,industrial raw materials and so on.Between these two styles,research on recovery technology of corn straw is slightly lagging behind the research on returning back to field,especially in technology for reaping both corn stalk and spike.This article have studied straw recycling technology installed in corn harvesters reaping both spikes and stalks,and the corn harvester adopts the multiple header,including upper and lower cut.The lower cut uses reciprocating cutter to shut off,straw-collecting stir dragon to collect,single-row roller structure to feed and transport and rotary chopper to cut up.The main target of this topic is to develop a stable and reliable type of corn harvester,which can achieve ear picking and maize straw recycling at the same time.The specific research work are as follows:1.Study of Straw Cutting MachineTo begin with,through comparative of advantages and disadvantages of existing four stem-cutting devices,the reciprocating cutter has been adopted,which has simple structure,reliable operation,and self-sharpening function.Meanwhile,a three-dimensional model has been established.Furthermore,the theoretical analysis of the reciprocating cutter is carried on,in which cutting principle;parameters of movement,cutting power and so on are analyzed.By this way,the reciprocating cutter’s technical parameters range is determined.Finally,by use of ANSYS software to conducting static simulation analysis,the cloud charts of structural and strain deformation under normal and limit cutting conditions are obtained.The charts suggest that the reciprocating cutter is able to bear force and deformation under any corn cutting conditions.Therefore,the reciprocating cutter is suitable for cutting corn stalks.2.Design of Chain Harrow ElevatorThe process of stalk transportation from reciprocating cutter to straw-collecting stir dragon is analyzed,from which we have discovered blind area between the two structures,and straw stalk easily getting jam in the blind area.To solve this problem,between reciprocating cutter and straw-collecting stir dragon,a selection of chain harrow elevator has been equipped,and its three-dimensional model is established to check interference.After completion of the whole machine manufacturing,the field test has been carried on.The experiment suggests the chain harrow elevator has eliminated the blind area between reciprocating cutter and straw-collecting stir dragon,which has received the design requirement.3.Study of Single-row Roller StructureFirstly,through analysis and comparative of advantages and disadvantages of double-layer roller and single-row roller structure,the single-row roller structure has been adopted to feed corn stalks from straw-collecting stir dragon to rotary chopper,which has simple structure,low power consumption and makes roller chopper be easily arranged.It adopts ratchet-roller structure,from front to back,the first roller is triangle,and the other ones are isosceles trapezoid.Besides,the first three rollers have the same diameters;the last one’s is slightly smaller.After the shape of the four rollers is determined,the two-dimensional diagram has been drawn and UG three-dimensional model has been established.Then,through movement analysis of the four feeding rollers,speed of the four rollers adopts the proposal of gradually increasing from the first to the last.In the later field experiment,it has been demonstrated that when the speed of the four rollers is respectively 170r/min、190r/min、354r/min、850r/min,the feeding effect is best.4.Study of Rotary ChopperAfter analysis and comparative of recent stem choppers,the rotary chopper is used to cut up stalks.Three-dimensional model of rotary chopper is established and the design parameters are analyzed and optimized.Finally,the field experiment is carried on,from which we found that in case of the chopper speed is constant,rotary chopper with 8 shredding knife not only works best,but also be favorite for throwing work.