铝挤压机培训资料1docx.docx

铝挤压机培训资料1docx.docx

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铝挤压机培训资料1docx

AluminumProfileExtrusion

ShandongUniversity

2010.06

Contents

Chapter1ProcessofExtrusionofAluminum

1.1ProcessOverview

Thealuminumextrusionprocessreallybeginswiththedesignprocess,foritisthedesignoftheproduct--basedonitsintendeduse--thatdeterminesanyoftheultimateproductionparameters.Questionsregardingmachinability,finishing,andenvironmentofusewillleadtothechoiceofalloytobeextruded.Thefunctionoftheprofilewilldeterminethedesignofitsformand,hence,thedesignofthediethatshapesit.

Oncethedesignquestionshavebeenanswered,theactualextrusionprocessbeginswithbillet,thealuminummaterialfromwhichprofilesareextruded.Thebilletmustbesoftenedbyheatpriortoextrusion.Theheatedbilletisplacedintotheextrusionpress,apowerfulhydraulicdevicewhereinarampushesadummyblockthatforcesthesoftenedmetalthroughaprecisionopening,knownasadie,toproducethedesiredshape.

Fig.1.1Thisisasimplediagramofatypicalhorizontalhydraulicextrusionpress;thedirectionofextrusionhereisfromlefttoright.

Thatisasimplifieddescriptionoftheprocessknownasdirectextrusion,whichisthemostcommonmethodinusetoday.Indirectextrusionisasimilarprocess,butwithsomeimportantdifferences.Inthedirectextrusionprocess,thedieisstationaryandtheramforcesthealloythroughtheopeninginthedie.Intheindirectprocess,thedieiscontainedwithinthehollowram,whichmovesintothestationarybilletfromoneend,forcingthemetaltoflowintotheram,acquiringtheshapeofthedieasitdoesso.

Theextrusionprocesshasbeenlikenedtosqueezingtoothpasteoutofatube.Whenpressureisappliedattheclosedend,thepasteisforcedtoflowthroughtheopenend,acceptingtheroundshapeoftheopeningasitemerges.Iftheopeningisflattened,thepastewillemergeasaflatribbon.Complexshapescanbeproducedbycomplexopenings.

Fig.1.2Thesephotosshowanewlengthofextrudate,justemergingfromthepress（left）andtheproductionofaprofileinprogress（right）.

注释：

Maincylinder[′silində]主液压缸

Hydraulicpressure[haɪ′drɔ:

lɪk]液压

Presscolumn[′kɔləm]柱式压机

Container挤压筒

Dummyblock[′dʌmi:

]挤压垫

Ram挤压杆

Billet坯料

Frontplaten挤压机前牌坊，前挤压盘

Runouttable输出辊道

Ribbon[ˈribən]带状物

Squeeze[skwi:

z]榨取,挤出

1.2Billet

Billetisthestartingstockfortheextrusionoperation.Extrusionbilletmaybeasolidorhollowform,commonlycylindrical,andisthelengthchargedintotheextrusionpresscontainer.Itisusuallyacastproductbutmaybeawroughtproductorpowdercompact.Oftenitiscutfromalongerlengthofalloyedaluminum,knownasalog.

Alloysaremetalscomposedofmorethanonemetallicelement.Aluminumextrusionalloyscontainsmallamounts（usuallylessthanfivepercent）ofelementssuchascopper,manganese,silicon,magnesium,orzinc.Thesealloyingelementsenhancethenaturalpropertiesofaluminumandinfluencetheextrusionprocess.

Billetlengthvariesaccordingtoanumberoffactors,includingthedesiredlengthofthefinishedprofile,theextrusionratio,thelengthoftherun-out,andtherequirementsoftheextrusionpress.Standardlengthsmayrunfromabout26inches（660mm）upto72inches（1,830mm）.Theoutsidediametermayrangefrom3inches（76mm）to33inches（838mm）;6-inch（155mm）to9-inch（228mm）diametersarethemostcommon.

注释：

Copper[′kɔpə，′kɒpə（r）]铜

Manganese[′mæŋɡəni:

z]锰

Silicon[′silikən]硅

Magnesium[mæg′ni:

zi:

əm,-ʒəm]镁

Zinc[ziŋk]锌

Wrought[rɔ:

t]制造的;形成的;精炼的,锻成的

Metallic[miˈtælik]金属的

1.3DiesandTooling

Diescanbemadetoformavirtuallylimitlessarrayofshapesandsizes.Severalfactorsinfluencetheactualcostandlead-timeofaspecificdie;thebestcombinationofproductperformance,qualityandcostisachievedwhentheproductdesigner,thediemaker,theextruder,andthepurchaserrecognizeeachother’srequirementsandworktogether.

Atypicalextrusionoperationwillmakeuseofadieassembly,includingthedieitself,which,togetherwithabacker,isenclosedwithinadiering,placedinfrontofabolster,withasub-bolsterbehind,allheldtogetherasaunitbyatoolcarrier.Thebacker,bolster,andsub-bolsterprovidethenecessarysupportforthedieduringtheextrusionprocess.

Fig.1.3Thisdiagramshowsthecomponentsthattypicallymakeupadieslide,thetoolingassembly,forasoliddie.

注释：

Platen挤压机前牌坊，挤压盘

Bolster[′bəʊlstə]前垫

Backer模垫

Die模具

Diering模套

Stem挤压杆

Dummyblock挤压垫

Liner挤压筒内衬

Container挤压筒

Dieslide模架

Pressurering压力垫圈

Horseshoe马蹄形止口

Theextrusiondie,itself,isasteeldisk（normallyH13）withanopening,thesizeandshapeoftheintendedcross-sectionofthefinalextrudedproduct,cutthroughit.

Diesarebroadlygroupedassolid（orflat）dies,whichproducesolidshapes,andhollowdies,whichproduceholloworsemi-hollowshapes.Combinationsofsolid,semi-hollow,and/orhollowshapesmaybeincorporatedintoasingledie.

Asoliddiemayhaveoneormoreorificesoraperturesthroughwhichthesoftenedalloyisforced（extruded）.Multipleaperturesinasingledieproducemultipleextrusionswitheachstrokeofthepress.

Soliddiesmay,onoccasion,beusedtoproducehollowprofilesbymeansofafixedorfloatingmandrel.Theuseofamandrelforextrudingahollowshapethroughaflatdieusuallyinvolvestheuseofhollowbillets,cylindricalsourcestockthatmayhavebeencastorbored.Piercingmandrels,however,donotrequiretheuseofcoredbillet.

Fig.1.4Asoliddie,asshownhere,producesshapeswithoutanyenclosedvoidsand/orsemi-hollowconditions.

注释：

Orifices[′ɔ:

rəfɪs,′ɔr-]模孔

Apertures[′æpətjuə]模孔

Mandrel[′mændril]心轴、模芯

Piercingmandrel穿孔针

Asemi-hollowdieextrudesashapethatisnearlyhollow,partiallyenclosingavoid,theareaofwhich（theareaofthedietongue）islargeincomparisonwiththegapwherethetongueisconnectedtothemainbodyofthedie.

Whileasolidorsemi-hollowdieisasinglepiece,itrequiressupportfromadditionaltoolscalledbackersandbolsters.Dependingonthecomplexityoftheextrudedshape,thetotalcostoftheextrusiontoolingmayincludechargesforthesesupplementaltools.

Fig.1.5Asemi-hollowdiealsoproducesshapeswithoutenclosedvoids;however,unlikeasoliddie,itproducesshapeswithatongueratioof3:

1orgreater.

Hollowdiestakeavarietyofforms.Bridge,porthole,andspiderdies,forexample,includeafixedstubmandrelasanintegralpartofthedie.Eachtypeofhollowextrusiondieservescertainfunctionsandcarriesitsownadvantagesanddisadvantages.Themanufacturingmethodsandcostsvarywidely.Thechoiceofdesign,andevenmanufacturingmethods,willdependontheprofile,pressandcontainersize,andproductionrequirements.

Fig.1.6Ahollowdieproducesshapeswithoneormoreenclosedvoids.Thedieshownhere,whenusedtogetherwithamandrelandothersupporttooling,producesaprofilewithsixvoids.

Themostcommontypesofhollowdiesaretheportholeandpancake.Theytypicallyarethemostcosteffectiveandeasiesttomanufacture,allowingthedesignertobemuchmorecreativeintheplacementandshapingoftheportsandfeed.TheyarealsotheeasiestforCNCMachining（ComputerNumericControl）,whichallowsforthediemakeranddiecorrectortoquantifyanyalterationsforproductionimprovementsonfuturedies.

Acriticallyimportantcharacteristicofextrusiondiesisthattheeffectivebearinglengthcontrolsthemetalflowthroughthedie.Theobjectiveistohaveallpartsoftheprofileemergefromthedieatthesamespeed.Thelongerthebearinglength,thegreatertheresistancetotheflowofaluminumandtheshorterthebearinglength,thelessresistancetoflow.Througheffectivedesign,thethickpartsofaprofilecanbeslowedthroughtheuseoflongerbearingstomatchthespeedofthethinnerpartswithshortbearings.

注释：

Porthole[′pɔ:

tˌhəʊl,′pəʊrt-]分流孔

Pancake饼状

Bearing[ˈbɛəriŋ]工作带

Resistance[riˈzistəns]抵抗,反抗,抵抗能力

Profile[ˈprəufail]型材

1.4DirectExtrusionOperation

Fig.1.7Thisdiagramshowsthebasicstepsinvolvedinextrudinganaluminumprofile.

Oncetheshapeofthefinalproducthasbeenidentified,theproperalloyselected,andthedieprepared,tomakereadyfortheactualextrusionprocess,thebilletandextrusiontoolsarepreheated.Duringextrusion,thebilletisstillsolid,buthasbeensoftenedinaheatingfurnace.Themeltingpointofaluminumvarieswiththepurityofthemetal,butisapproximately1,220°Fahrenheit（660°Centigrade）.Extrusionoperationstypicallytakeplacewithbilletheatedtotemperaturesinexcessof700°F（375°C）,and--dependinguponthealloybeingextruded--ashighas930°F（500°C）.

Theactualextrusionprocessbeginswhentheramstartsapplyingpressuretothebilletwithinthecontainer.Varioushydraulicpressdesignsarecapableofexertinganywherefrom100tonsto15,000tonsofpressure.Thispressurecapacityofapressdetermineshowlargeanextrusionitcanproduce.Theextrusionsizeismeasuredbyitslongestcross-sectionaldimension,sometimesreferredtoasitsfitwithinacircumscribingcirclediameter（CCD）.

Aspressureisfirstapplied,thebilletiscrushedagainstthedie,becomingshorterandwideruntilitsexpansionisrestrictedbyfullcontactwiththecontainerwalls.Then,asthepressureincreases,thesoft（butstillsolid）metalhasnoplaceelsetogoandbeginstosqueezeoutthroughtheshapedorificeofthedietoemergeontheothersideasafullyformedprofile.

About10percentofthebillet,includingitsouterskin,isleftbehindinthecontainer.Thecomplete