机械毕业设计英文外文翻译328免耕播种机锯切防堵装置设计及其切割机理的研究.docx

机械毕业设计英文外文翻译328免耕播种机锯切防堵装置设计及其切割机理的研究.docx

《机械毕业设计英文外文翻译328免耕播种机锯切防堵装置设计及其切割机理的研究.docx》由会员分享，可在线阅读，更多相关《机械毕业设计英文外文翻译328免耕播种机锯切防堵装置设计及其切割机理的研究.docx（15页珍藏版）》请在冰点文库上搜索。

机械毕业设计英文外文翻译328免耕播种机锯切防堵装置设计及其切割机理的研究

附录

Designofsawinganti-blockingmechanismfor

no-tillageplanteranditscuttingmechanism

LiaoQingxi1,GaoHuanwen2,ShuCaixia1

Abstract:

Basedonblockingissuesofno-tillageplanterfordry-landfarmingintwo-crop-a-yearregioninNorthofChinaandshortcomingsofanti-blockingmechanismdeveloped,suchashigherrotationspeed（above1500r/min）andbiggerpowerconsumption（widthpowerconsumptionperunitupto16～41.74kW/m,includingtractionpower）,anewsawinganti-blockingmechanismwasdevelopedanditscuttingmechanismwasinvestigatedinthispaper.Meanwhilestressdistributionofthesaw-toothbladecalculatedbytheANSYSfinityelementsoftwareshowedthatthesaw-toothbladewouldbefeasibletocutcornstraws.Experimentalresultsinthesoilbinshowedthat:

1）Thesawinganti-blockingmechanismwithtwocuttingmodesofsustainingandno-sustainingcutcouldrealizeanintegratedfunctionofcuttinganddirectlythrowingbyreverserotation,namely,itcouldthrowstrawsdirectlytotherearoftheopenerbyformerangleofsaw-toothandthrower;2）Thecuttingrateofstrawswouldincreasealongwiththerisingofstrawmoistureandrotationspeed,andhighermoistureofstrawswouldbeofbenefittoimprovingcuttingquality;3）Thecuttingrateofstrawswoulddecreasealongwiththerisingofvelocityofvehiclewhileintervalofthemovedandfixedbladewasdetermined.Andthesawinganti-blockingmechanismhadhighercuttingqualityandlowerpowerconsumptionwithoutleakycuttingandtearingoutwithsmallintervalofthemovedandfixedblade.Comparedwithotherdrivinganti-blockingmechanisms,theoreticalanalysisandexperimentalresultsshowedthatthesawinganti-blockingmechanismhadfinecutcapabilityandlowerrotationspeed（650r/min）andlowerpowerconsumption（powerconsumptionperunitwidthupto2.95kW/m）aswellasstrongersuitabilitytodifferentstubblesmulch.Additionally,anewwaywasfoundouttoimproveanti-blockingperformanceofno-tillageplanter.

Keywords:

no-tillageplanter;sawinganti-blockingmechanism;cuttingmechanism;cuttingrate

1　Introduction

　Anti-blockingissueofno-tillageplanterhadbecomeoneofthekeyfactorsaffectingproductionefficiencyandseedingqualityoftwo-crop-a-yearregioninNorthofChina.Itwasbecausetherewasagreatdealofcropstubblesandcropseedingwasstartedshortlyaftercrophadbeenharvested,leavingnotimeforcropstubblestodecay.Atpresent,therearetwomethodstosolveanti-blockingissueofno-tillage:

1）Strawswerechoppedbythestrawchopperbeforeseeding,itwouldleadtoaddingworkingprocedureandincreasecostsofproductionaswellasdelayingseedingtime;2）Stubbleswereclearedoutbydrivingchoppingmechanismfixedonno-tillageplanter,suchasStripWheatSpinningandFurrowPlantermadeinHebeiNonghahaMachineryLtdCorporationand2BMDF-CornStripChoppermadeinChinaAgriculturalUniversity[1]andsoon.Inpracticethedrivingchoppingmechanismhadsignificanteffectonantiblocking,butalsobiggervibrationandnoiseaswellaslowersecuritybecausestrawswerechoppedathighrotationspeed.

　Itwasreportedthatthebladebaselinearvelocityofseveralmainstrawchoppingmechanismswasbetween37～56m/s[2],mostlychoppingmechanismcombinedwithcuttingandstrikinghadhigherstrikingvelocityandhigherpowerconsumption[3],e.g.thebladebaselinearvelocityupto34m/scouldobtainfinecuttingeffectforcornstraws[4],and24m/sonriceandwheatstrawsbysupportingpole,respectively[5].Evenifcornstrawswerecutbyslidingcutwithverticalblade,itsvelocityofcuttingonestraw,twostrawsandthreestrawsmustbeupto10.3m/s,13.6m/s,15.8m/s[6],respectively,andhadhigherpowerconsumption.Inaword,becausethedrivingchoppingmechanismdevelopedpresentlyhadhighrotationspeed（above1500r/min）andhigherpowerconsumption（widthpowerconsumptionperunitupto16～41.74kW/m,includingtractionpower）,todecreaserotationspeedandpowerconsumptionwouldbeurgentinpractice.

　Basedonpracticalproblems,theobjectiveinthispaperistofindawaytosolvetheshortcomingthatit64isdifficultforcommonsmoothbladetoseizestrawsanditmustrunathigherrotationspeed,decreasepowerconsumptionandimprovecuttingeffectaswellasanti-blockingperformanceofno-tillageplanter.Additionallysomeexperimentsweredonebyselectingsaw-toothascuttingbladeofno-tillageplanterandcuttingmechanismofthesawinganti-blockingmechanismwasinvestigated.

2　Structureandcuttingruleofthesawinganti-blockingmechanism

2.1　Structureandcharacteristics

　Thesawinganti-blockingmechanismwasmadeupofsaw-toothblade,throwingbandevice,principalshaft,movedandfixedbladecombination,coveringshell,openerandworkingframeaswellastransmissionsystem.Sketchofthesawinganti-blockingmechanismisshowninFig.1.Themainpartsincludedsaw-toothblade,throwingbandeviceaswellasfixedbladecombinations.Diameterofsaw-toothwith60teethwas350mm;throwingbandevicewithmax270mmturningdiameterwasfixedonbetweenadjacentsaw-teeth;fixedbladecombinationsconsistedoffixedbladewithtoothandverticaltypeblade,andtoothtypebladesametosaw-tooth,Moreover,theverticaltypebladewouldbeusedtoobstructstrawswithoutcuttingfromthrowingareaandparticipatedincuttingstraws.Thesawinganti-blockingmechanismwasfixedonthesoilbindevice,itswidthwas600mm,theintervalofadjacentopenerswas200mm.Thesawinganti-blockingmechanismhadmanycharacteristicssuchasstrawswouldbechoppedbysaw-toothbladeandfixedbladecombinations,andhadtwocuttingmodeswithsusta-iningandno-sustainingcutting,thebladebaselinevelocityofsaw-toothwaslowertotossingbladetype,namely,thesawinganti-blockingmechanismcouldchangehigherspeedhewingintolowerspeedsawing.

2.2　Cuttingprinciple

　Thesawinganti-blockingmechanismwasdriventoreverserotationbypower.First,strawswerecutinno-sustainingmodebysaw-toothbladeswhilesaw-toothbladestouchedstraws,thenafterstrawswerecompletelycutdown,theywouldbefreeandbethrowntotherearofopenerbythrowingbandeviceandinertialforce.Second,strawsnotbeingcompletelycutdownwouldbethrowntoformerupwardandbecutinsustainingmodebyfixedbladecombinationsuntilanyofstrawswouldbecutdown,strawshavingbeencutdownwerethrowntotherearofopenerbythrowingbandeviceandsaw-tooth.Inturn,timeaftertime,strawswouldbecarriedoutcontinuouslytocutandthrowbythesawinganti-blockingmechanism.Thelowestpointofthesaw-toothbladeskept15～30mmintervalfromthesoil.Intermsofspreadingstatusofstrawsinfieldexistedperpendicularityorcertainanglewithmarchingdirection,sawprincipalinlandscapeorientationhadbeendeterminedforthesawinganti-blockingmechanisminordertodecreaserepeatedcutting,leakycuttingandtearingout.

　Workingproceduresofthesawinganti-blockingmechanismwereasfollows:

1）no-sustainingcutphase:

staticstrawsrelativetogroundwerecutfirstlyatNpointbysaw-toothblades,then,strawswouldbecutdowncompletelyorembeddedinsaw-tooth.Strawsbeingcutdowncompletelywouldbefreeand65　LiaoQingxietal:

Designofanti-blockingmechanismforno-tillageplanterdroppedintoadjacentsaw-tooth;2）dragginganddeliveringphase:

afterstrawsdroppedintoadjacentsaw-tooth,theywouldbethrowntoformerupwardbythethrowingbandevice,moreover,strawsembeddedinthesaw-toothwouldbethrowntoformerupwardbythesaw-toothathigherspeedrotation;3）sustainingcutphase:

strawsnotbeingcutdowncompletelyinno-sustainingcutphasewouldbecutinsustainingmodebyfixedbladecombinationsatKpointuntilanyofstrawswouldbecutdowncompletely;

4）throwingphase:

strawsbeingcutdownwerethrowndirectlytotherearofopenerbytoothformerslantingangleofthesaw-toothandthrowingbandevice,timeandagain,strawswouldbecarriedoutcontinuouslytocutandthrow.Theworkingprincipleofthesawinganti-blockingmechanismisshowninFig.2.

2.3　Analysisofmechanicscharacteristicsofsaw-toothblade

Cuttingpropertiesofsaw-toothtocutstrawsbelongtowrigglycutofno-metalmaterials,itsultimateobjectiveisnotonlytoimprovesurfacecuttingquality,butalsotoraisecuttingefficiency,soitcandecreasesawingforceandpowerconsumption[9].Becausetheratioofitsdiameter350mmtoitsthickness1.8mmisover150,thesaw-toothbladebelongstoexceedthindisc.Itisasplanestressandno-axissymmetryproblemaccordingtoelasticitytheory.Andbecausethesaw-toothbladewastightenbyflangetray,sixfreedomsofitscenterholewererestricted,soitscenterpartscouldberegardedasrestrictedstatuscompletelynottobringanydisplacementandrotation.Saw-toothbladebelongstoexcessivebladetools,itwouldbringtoalternativesawingforcesincuttingstraws,Thereasonsliedin:

1）structureofstrawswithinneremptyandoutsidehardnesshaddeterminedmicro-hardnessun-uniformitydistribution,sothesingletoothforcewouldbeuncertainincuttingstraws;2）thetotalsawingforcesofsaw-toothinhorizontaldirectionwouldbeuncertainbecausethetoothofsaw-toothbladeisnotcontinuous.Thesealternativecharacteristicswouldbringtotransfigurationofthesaw-tooth,moreover,thetransfiguredpropertiesansizewasrelativetothestresspropertiesandsizeofthesaw-toothinsupportingoutsideloading.So,itwasveryessentialtomakeclearstressdistributionofthesaw-toothinordertoensuresmoothcutting.

　Thestressdistributionof