会员注册 | 登录 | 微信快捷登录 QQ登录 微博登录 | 帮助中心 人人文库renrendoc.com美如初恋!
站内搜索 百度文库

热门搜索: 直缝焊接机 矿井提升机 循环球式转向器图纸 机器人手爪发展史 管道机器人dwg 动平衡试验台设计

外文翻译切削刀具.doc外文翻译切削刀具.doc -- 5 元

收藏

编号:201311171407276462    大小:153.05KB    格式:DOC    上传时间:2013-11-17
  【编辑】
5
关 键 词:
专业文献 学术论文 精品文档 外文翻译
资源描述:
英文原文CUTTINGTOOLSWhenselectingcuttingtoolsforajob,thefirstthingtoconsideriswhattypeofoperationneedstobeperformed.Hereisaquickdescriptionofthebasiccuttingtoolsmostoftenusedinmillingoperations.DRILLAdrillisusedtocreatearound,cylindricalholeinaworkpiece.Drilledholescanbe"throughholes"or"blindholes".A"blindhole"isnotcutentirelythroughaworkpiece.Quiteoften,anengineeringblueprintwillspecifyadrilledholetobedrilledto"fulldiameterdepth."Thismeansthattheholediametermustbeaspecifieddepthwithoutregardtotheangledtipofthedrill.Whenyoumeasureyourtoollengthoffset,youaremeasuringthelengthofthedrillanditstip.Sohowdeepdoyoudrilltheholesothatthefulldiameterdepthiscorrect?Well,youneedtoknowhowlongthedrillpointis.TIP:Thelengthofthedrillpointisdeterminedbythetoolpointangleandthedrilldiameter.Youcancalculatethelengthofthedrillpointbymultiplyingthedrilldiameterbyaconstant;thevalueoftheconstantdependsonthedrillpointangle(moststandardhigh-speedsteeldrillshaveatoolpointangleof118degrees).Foradrillpointangleof:118degrees135degrees141degreesMultiplythedrilldiameterby:0.30.2070.177Usingtheseconstantsallowsyoutocalculatethedrillpointlengthwithinafewthousandthsofaninch.CENTERDRILLAcenterdrillisasmalldrillwithapilotpoint.Itisusedtocreateasmallholewithtaperedwalls.Whenahole'slocationmustbeheldtoaclosetolerance,useacenterdrillfirstandthenuseatwistdrilltofinishthehole.Thetaperedwallsofthecenter-drilledholewillkeepthetwistdrillstraightwhenitbeginstodrillintotheworkpiece.TIP:Manymachinistsusethisruleofthumb:Ifthetoleranceofthediameterofacenter-drilledholeisnotcritical,drillasdeepasyouwantthisdiametertobe.Withastandard,60-degreecenterdrillbelow0.375-inchdiameter,theholediameterproducedwillbeclosetothedepthyoudrilled.Withlargercenterdrills–0.375inchandabove–thedepth-to-diameterratiobecomeslarger,soyoucouldbeoffbyasmuchas0.080to0.100inch.REAMERAreamerisdesignedtoremoveasmallamountofmaterialfromadrilledhole.Thereamercanholdveryclosetoleranceonthediameterofahole,andgiveasuperiorsurfacefinish.Theholemustbedrilledfirst,leaving0.005to0.015inchofstockonthewallsoftheholeforthereamertoremove.TIP:Theidealsituationforholesizeaccuracyandlocationwhenreamingistoprocesstheholewiththefollowingsteps:theholeisfirstdrilled,thenbored,thenreamed.TIP:Stockallowanceforareamedholewilldependonthesizeofthehole.Ageneralruleis:forholeslessthan1/2"forholesgreaterthan1/2"stockoflessthan0.0150"ondiameterstockof0.030"ondiameterThetypeofworkpiecematerialandthemethodusedtocreatetheholewillaffectthestockallowance.TIP:Areamerproducesthebest,mostuniformsurfacefinishwhenitisfedintoandoutoftheholeusingtheG85(borein,boreout)cannedcycle.ManypeopletrytosavetimebyusingtheG81(drill)cannedcycle,whichwillfeedintoaholeandrapidout.ItisquickerthanG85,butwillusuallyleaveahelicalswirlmarkonthecylindricalsurfaceofthehole.Althoughthisswirlmarkisonlyacosmeticflawanddoesn'taffectthesizeofthehole,theappearanceoftheholemayberejectedbysomecustomers.TAPAtapisusedtocreatescrewthreadsinsideofadrilledhole.NOTE:Greatcaremustbetakenwhenusingamillingmachinetoperformatappingoperation.TIP:Ifyouareusingamachinewithrigidtapping,feedrate(ininchesperminute)=threadpitchxrevolutionsperminute.Also,youshouldnevertapmorethan1.5xthetap'smajordiameter.Threadedconnectionswillnotincreaseinstrengthifthecontactlengthismorethan1.5timesthediameterofthefastener.Ifyouneedthreadsthataredeeper,machinetapthemfirstandhand-tapthemtofinisheddepth.Ifyoutapdeeperthan1.5xtheholediameter,yourchancesofbreakingthetapincreasedramatically.Chipcontrolbecomesaproblem.Whentappingblindholes,alwaysdrillasdeepaspossibletoavoidpackingchipsbelowthetap.Usingaspiralflutetapwillbringthechipsup,outofthehole.Tofurtherreducetappingheadaches,makesureallholestobetappedarefreeofchips,anduseatappingfluidspecificallydesignedforthetypeofmaterialyouarecutting.TIP:Tapdrillsizeisthesizeoftheholerequiredforaspecifictap.For75%effectivethreadstheformulathatwilldeterminethecorrectdrillsizeis:D–1/N,whereD=majordiameterofthetapandN=numberofthreadsperinchAtappedholewith75%ofthreaddepthhasonly5%lessstrengththan100%threadandtakesonly1/3ofthecuttingforceofa100%thread.ENDMILLAnendmillisshapedsimilartoadrill,butwithaflatbottom.Itisusedprimarilytocutwiththesideofthetooltocontourtheshapeofaworkpiece.TIP:Programminganendmilltocutcontourorpockettoolpathsusingcuttercompensation(G41andG42)allowsyoumuchmoreflexibilityinadjustingthesizeofmachinedfeatures.Usingcuttercompensationallowsyoutoadjusttheamountofstockremoval.Asanendmillwears,minoroffsetadjustmentsallowyoutomakeeverypartthesamesize.Youmayalsouseadifferentsizeendandhavethemachinecutthesamepartfeaturesaswiththeendmilloriginallyprogrammedforthattoolpath.BULLENDMILLAbullendmillisthesameasaregularendmillexceptthatthereisaradiusonthecornerwheretheflutesmeetthebottomoftheendmill.Thisradiuscanbeanysizeuptoone-halfofthetool'sdiameter.TIP:Bullendmillsareeffectiveforproducingacornerradiusbetweenawallandaflooronagivenpartfeature.Theyalsoaddtothestrengthofanendmill.Whenmachininghard,toughtocutmaterials,thesharpcornersonastandardendmilltendtochipandwearfasterthananendmillwithacornerradius.Theradiusonabullendmillprovidesamoregradualshearingentryintotheworkpiece.BALLENDMILLAballendmillisabullendmillwherethecornerradiusisexactly1/2thetool'sdiameter.Thisgivesthetoolasphericalshapeatthetip.Itcanbeusedtocutwithsideofthetoollikeanendmill.TIP:Theprimarypurposeofaballendmillistomachineloftedsurfaces.Thesphericalshapeofthetoolisabletomovealonganyundulatingsurfaceandcutanywherealongthecutter's"ballend."Asaballcanrolloverasurface,aballendmillcanbeusedtocutanysuchsurface.INSERTENDMILLAninsertendmillisthesameasastandardendmillbutwithreplaceablecarbideinserts.TIP:Insertendmillsaredesignedtoremovemetalathigherratesthansolidcarbide.Theycomeinalargerangeofdiametersandareabletocutatadeeperdepthofcut.Thisisfantasticbut,whenusingthesecutters,itisagoodideatocalculatethehorsepowerrequiredtomakeacut.PieceofcakeonyourHaascontrol:Thereisabuttononthefrontlabeled"HELP/CALC."PressthisbuttononcetogettheHelpmenu,pressitagaintogettheCalculatorfunctions.UsethePAGEUP/PAGEDOWNkeystoscrollbetweenthreepages:TrigonometryHelp,CircularInterpolationHelp,andMillingHelp.Eachoneofthesepageshasasimplecalculatorintheupperlefthandcorner.OntheMillingHelppage,youcansolvethreeequations:1.SFM=(cutterdiameter[in.])*RPM*3.14159/122.(Chipload[in.])=(feed[in.permin.])/RPM/#offlutes3.(Feed[in.permin.])=RPM/(threadpitch)Withallthreeequations,youmayenterallbutoneofthevaluesandthecontrolwillcomputeanddisplaytheremainingvalue.Tocalculatethehorsepowerrequiredforacut,youmustentervaluesforRPM,feedrate,numberofflutes,depthofcut,widthofcut,andchooseamaterialfromthemenu.Ifyouchangeanyoftheabovevalues,thecalculatorwillautomaticallyupdatetherequiredhorsepowerforthecutyouintend.Thenextthingtoconsiderwhenchoosingcuttingtoolsforajobiswhatmaterialyouaregoingtocut.Themostcommonmaterialscutinthemetalworkingindustrycanbedividedintotwocategories:non-ferrousandferrous.Non-ferrousmaterialsincludealuminumandaluminumalloys,copperandcopperalloys,magnesiumalloys,nickelandnickelalloys,titaniumandtitaniumalloys.Commonferrousmaterialsincludecarbonsteel,alloysteel,stainlesssteel,toolsteel,andferrouscastmetalslikeiron.Non-ferrousmetalsaresofterandeasiertocut,withtheexceptionofnickelandtitanium.Ferrousmetals,ontheotherhand,aregenerallyharderincompositionandtoughertocut.Cuttingtoolmaterialisoneofthebiggestdecisionsyou'llhavetomakewhenchoosingacuttingtool.Mostallofthecuttersdescribedaboveareavailableinthreebasicmaterials:high-speedsteel,solidcarbide,andcarbideinsertstyle.Almostallofthebasiccuttingtoolmaterialscanbeusedtocutalmostallmaterials.Itreallyboilsdowntoperformance.High-speedsteelcuttingtoolshaveveryhightoughnessbutlackwearresistance.Carbide,ontheotherhand,hasaveryhighwearresistancebutchipsandbreakseasily.Carbidewillalwaysbeabletocutmaterialsathigherspeedsandfeeds,butismoreexpensive.Carbideinsertcuttingtoolsareveryusefulinhigh-productionsituationsbecausetheinsertsaredesignedwithmultiplecuttingedgesoneachinsert.Whentheybecomewornout,youindextheinsertstothenextcuttingedge,andwhenallcuttingedgesareused,youonlyreplacetheinsertsandnotthewholetool.TIP:Ifyouareusingahigh-speedsteeldrill,alwaysuseacenterdrilltogettheholestarted.Thendrillthehole.Thiswillensurethatthedrilledholeisinthecorrectlocation.Ifyouareusingacarbidedrill,itisnotnecessarytocenterdrillfirstbecausecarbidedrillsaregroundwithaself-centeringtip.Usingacarbidedrilltodrillaholethatisalreadycenterdrilledwilldamagethedrill.Theoutercuttingedgeswillcontactthetaperedwallsbeforethetipofthedrillbeginstocut.Thiswillshocktheoutercuttingedgesandcausethedrilltochip.Carbidedrillsmustbegintocutatthetipbeforetheoutercuttingedges.Eachoneofthesecuttingtoolmaterialsisavailablewithavarietyofdifferentcoatingstoenhancetheirperformance.Thethreecoatingsmostwidelyusetodayaretitaniumnitride(TiN),titaniumcarbonitride(TiCN),andtitaniumaluminumnitride(TiAlN).TiNcoatingiseasilyrecognizedbyitsgoldcolor.TheadvantagesofTiNcoatingareincreasedsurfacehardness,increasedtoollife,betterwearresistanceandhigherlubricity,whichdecreasesfrictionandreducesedgebuild-up.TiNcoatingismostlyrecommendedformachininglowalloysteelandstainlesssteel.TiCNcoatingisgraycoloredcomparedtoTiN,andevenharder.Itsadvantagesareincreasedcuttingspeedandfeeds(40%to60%highercomparedtoTiN),highermetalremovalrates,andsuperiorwearresistance.TiCNcoatingsarerecommendedformachiningallmaterialtypes.TiAlNcoatingappearsgrayorblackandisprimarilyusedtocoatcarbide.Itcanworkatveryhightemperatures,upto800degreesCelsius,whichmakesitidealforhigh-speedmachiningwithoutcoolant.Pressurizedairisrecommendedtoremovechipsfromthecuttingzone.Itworkswellonhardenedsteels,titaniumandnickelalloys,aswellasabrasivematerialslikecastironandhighsiliconaluminum.Whenselectingendmilltools,thenumberofflutes,orcuttingedges,isanimportantfactor.Themoreflutesanendmillhas,thesmaller,orshallower,theflutesare.Thesolidcentersectionofanendmillisapproximately52%oftheendmill'sdiameteronatwo-fluteendmill.Thecentersectionofathree-fluteendmillis56%ofitsdiameter,andanendmillwithfourormorefluteshasacentersectionthatis61%ofitsdiameter.Thismeansthatthemoreflutesanendmillhas,themorerigiditwillbeinthecut.Two-fluteendmillsarerecommendedforsoft,gummymaterialssuchasaluminumandcopper.Four-fluteendmillsarerecommendedforharder,toughersteelmaterials.中文译文切削刀具
温馨提示:
1: 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
2: 本站的文档不包含任何第三方提供的附件图纸等,如果需要附件,请联系上传者。文件的所有权益归上传用户所有。
3.本站RAR压缩包中若带图纸,网页内容里面会有图纸预览,若没有图纸预览就没有图纸。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 人人文库网仅提供交流平台,并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。
  人人文库网所有资源均是用户自行上传分享,仅供网友学习交流,未经上传用户书面授权,请勿作他用。
0条评论

还可以输入200字符

暂无评论,赶快抢占沙发吧。

当前资源信息

4.0
 
(2人评价)
浏览:30次
淘宝运营上传于2013-11-17

官方联系方式

客服手机:13961746681   
2:不支持迅雷下载,请使用浏览器下载   
3:不支持QQ浏览器下载,请用其他浏览器   
4:下载后的文档和图纸-无水印   
5:文档经过压缩,下载后原文更清晰   

相关资源

相关资源

相关搜索

专业文献   学术论文   精品文档   外文翻译  
关于我们 - 网站声明 - 网站地图 - 友情链接 - 网站客服客服 - 联系我们
copyright@ 2015-2017 人人文库网网站版权所有
苏ICP备12009002号-5