本科毕业论文（设计）外文原文题目：小型播种机的设计学院：机电工程学院专业：机械设计制造及其自动化班级：学号：姓名：指导教师：DevelopmentandexperimentofseedmeteringforgrassplotSeederYangSong,ZhangShumin,YiJintao,WengQiang(CollegeofEngineering,ChinaAgriculturalUniversity,Beijing100083，China)Abstract:Inordertodevelopagrassplotseeder,whichissuitableforcultivationoffinegrassvarieties,aseedmeteringtestplatformwasdevelopedwhichhasaspecialdesignedtransmissionmechanismandaseedcupwithanadjustablering.Severalkindsofseedscanbefedbyfeedingmechanisminfeedingcupwhenseedingshaftaswellasdistributorconerotatesonecompleterevolution.Seedmotionandtherelationshipbetweenseedoutletandseedcupwereanalyzedinthispaper.Resultoforthogonalexperimentshowedthatthenumberofsweeperbladeswasoneofthemaininfluencingfactorsofthevariationcoefficientofseedinguniformity.When12sweeperbladesand9groovesconewereusedintest,thevariationcoefficientofthePacesetter’sseedinguniformitygottotheminimumvalue16.46%.Thisresearchprovidesareferenceforgrassplotseeder’sdevelopment.Keywords:agriculturalmachinery,mechanisms,stressanalysis,plotseeder,grasscultivationdoi：10.3969/j.issn.1002-6819.2012.z2.013Documentcode:AArticleID:1002-6819(2012)-Supp.2-0072-06CLCnumber:S223.2+60.IntroductionItisimportanttoconductcomparabletestsinexperimentalplotswithbreeding,species,nutritionalvalueandproductionresearchforgrassresourceandanimalhusbandry[1].Therefore,plotseederplaysakeyrolefortheresearchandrangelanddevelopment.Thedesignrequirementsofgrassplotseederaresimilarwithconventionalplotseeder,whichneedtofeedauniformamountofseedoverthelengthofaplotandseedmeteringmustbecleanedbetweencontiguousplotsbecauseseveralspeciesandmixturesmaybeinthesameexperiment.Numerousplotseedershadbeendevelopedforagronomictrialsofseedingbeforeitwasappliedtoseedingrangeland.During1958to1960,EgilØyjorddesignedandimproveda4-row,a6-rowanda10-rowplotseeders,respectively.In1970’s,ØyjordplotseederswereexportedfromNorwayto57countries[2].HaroldG.Marshalldesignedaplotdrillwithamultipleoutletconewhichi