模具毕业设计论文外文翻译.doc

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1、InjectionMoldingThebasicconceptofinjectionmoldingrevolvesaroundtheabi1ityofathermoplasticmaterialtobesoftenedbyheatandtohardenwhencooled.Inmostoperations,granularmaterial(theplasticresin)isfedintooneendofthecylinder(usua1lythroughafeedingdeviceknownasahopper),heated,and

2、softened(plasticizedorplasticated),forcedouttheotherendofthecylinder,whi1eitisstillintheformofamelt,throughanozzleintoarelativelycoolmoldheldclosedunderpressure・Here,themeltcoolsandhardensunti1fullyset-up.Themoldisthenopened,thepieceejected,andthesequenccrepeated・Thus,t

3、hesignificantelementsofaninjectionmoldingmachinebecome:1)thewayinwhichthemeltisplasticized(softened)andforcedintothemold(calledtheinjectionunit);2)thesystemforopeningthemoldandclosingitunderpressure(calledtheclampingunit);3)thetypeofmoldused;4)themachinecontrols・Thepart

4、ofaninjection-moldingmachine,whichconvertsaplasticmaterialfromasoldphasetohomogeneousseni-1iguidphasebyraisingitstemperature・Thisunitmaintainsthematerialatapresenttemperatureandforceitthroughtheinjectionunitnozzleintoamold・Theplungerisacombinationoftheinjectionandplasti

5、cizingdeviceinwhichaheatingchamberismountedbetweentheplungerandmold・Thischamberheatstheplasticmaterialbyconduction.Theplunger,oneachstorke;pushesunmeltedplasticmaterialintothechamber,whichinturnforcesplasticmeltatthefrontofthechamberoutthroughthenozzleThepartofaninjecti

6、onmoldingmachineinwhichthemoldismounted,andwhichprovidesthemotionandforcetoopenandclosethemoldandtoholdthemoldclosewithforceduringinjection.Thisunitcanalsoprovideotherfeaturesnecessaryfortheeffectivefunctioningofthemoldingoperation.Movingplateisthememberoftheclampinguni

7、t,whichismovedtowardastationarymember.themovingsectionofthemoldisboltedtothismovingplate・Thismemberusuallyincludestheejectorholesandmoldmountingpatternofblotholesor“T"slots.Stationaryplateisthefixedmemberoftheclampingunitonwhichthestationarysectionofthemoldisbolted・This

8、memberusuallyineludesamold-mountingpatternofbolesorslots.Tierodsarememberoftheclampingforceactuatingmechanismt