会员注册 | 登录 | 微信快捷登录 支付宝快捷登录 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

   首页 人人文库网 > 资源分类 > DOC文档下载

外文翻译--计算机控制程序员与操作员该做什么.doc

  • 资源星级:
  • 资源大小:88.00KB   全文页数:12页
  • 资源格式: DOC        下载权限:注册会员/VIP会员
您还没有登陆,请先登录。登陆后即可下载此文档。
  合作网站登录: 微信快捷登录 支付宝快捷登录   QQ登录   微博登录
友情提示
2:本站资源不支持迅雷下载,请使用浏览器直接下载(不支持QQ浏览器)
3:本站资源下载后的文档和图纸-无水印,预览文档经过压缩,下载后原文更清晰   

外文翻译--计算机控制程序员与操作员该做什么.doc

英文原文WhatcomputercontrolprogrammersandoperatorsdoComputercontrolprogrammersandoperatorsusecomputerizednumericalcontrolCNCmachinestocutandshapeprecisionproducts,suchasautomobileparts,machineparts,andcompressors.CNCmachinesincludemachiningtoolssuchaslathes,multiaxisspindles,millingmachines,andelectricaldischargemachinesEDM,butthefunctionsformerlyperformedbyhumanoperatorsareperformedbyacomputercontrolmodule.CNCmachinescutawaymaterialfromasolidblockofmetal,plastic,orglassknownasaworkpiecetoformafinishedpart.Computercontrolprogrammersandoperatorsnormallyproducelargequantitiesofonepart,althoughtheymayproducesmallbatchesoroneofakinditems.TheyusetheirknowledgeoftheworkingpropertiesofmetalsandtheirskillwithCNCprogrammingtodesignandcarryouttheoperationsneededtomakemachinedproductsthatmeetprecisespecifications.BeforeCNCprogrammersalsoreferredtoasnumericaltoolandprocesscontrolprogrammersmachineapart,theymustcarefullyplanandpreparetheoperation.First,theseworkersreviewthreedimensionalcomputeraided/automateddesignCADblueprintsofthepart.Next,theycalculatewheretocutorboreintotheworkpiece,howfasttofeedthemetalintothemachine,andhowmuchmetaltoremove.Theythenselecttoolsandmaterialsforthejobandplanthesequenceofcuttingandfinishingoperations.Next,CNCprogrammersturntheplannedmachiningoperationsintoasetofinstructions,Theseinstructionsaretranslatedintoacomputeraided/automatedmanufacturingCAMprogramcontainingasetofcommandsforthemachinetofollow.Thesecommandsnormallyareaseriesofnumbershence,numericalcontrolthatdescribeswherecutsshouldoccur,whattypeofcutshouldbeused,andthespeedofthecut.CNCprogrammersandoperatorschecknewprogramstoensurethatthemachinerywillfunctionproperlyandthattheoutputwillmeetspecifications.Becauseaproblemwiththeprogramcoulddamagecostlymachineryandcuttingtools,computersimulationsmaybeusedtochecktheprograminsteadofatrialrun.Iferrorsfound,theprogrammustbechangedandresteduntiltheproblemisresolved.Inaddition,growingconnectivitybetweenCAD/CAMsoftwareandCNCmachinetoolsisraisingproductivitybyautomaticallytranslatingdesignsintoinstructionsforthecomputercontrolleronthemachinetool.ThesenewCAMtechnologiesenableprogramstobeeasilymodifiedforuseonotherjobswithsimilarspecifications.Aftertheprogrammingworkiscompleted,CNCoperatorsalsoreferredtoascomputercontrolledmachinetooloperatorsperformthenecessarymachiningoperations.TheCNCoperatorstransferthecommandsfromtheservertotheCNCcontrolmoduleusingacomputernetworklinkorfloppydisk.Manyadvancedcontrolmodulesareconversational,meaningthattheyasktheoperatoraseriesofquestionsaboutthenatureofthetask..CNCoperatorspositionthemetalstockontheCNCmachinetoollathe,millingmachine,orothersetthecontrols,andletthecomputermakethecuts.Heavierobjectsmaybeloadedwiththeassistanceofotherworkers,autoloaders,acrane,oraforklift.Duringthemachiningprocess,computercontroloperatorsconstantlymonitorthereadoutsfromtheCNCcontrolmodule,checkingtoseeifanyproblemsexist.Machinetoolshaveuniquecharacteristics,whichcanbeproblematic.Duringamachiningoperation,theoperatormodifiesthecuttingprogramtoaccountforanyproblemsencountered.Unique,modifiedCNCprogramsaresavedforeverydifferentmachinethatperformsatask.CNCoperatorsdetectsomeproblemsbylisteningforspecificsoundsforexample,dullcuttingtoolorexcessivevibration.Dullcuttingtoolsareremovedandreplacedandreplaced.Machinetoolsrotateathighspeeds,whichcancreateproblemswithharmonicvibrationsintheworkpiece.vibrationscausethemachinetoolstomakeminorcuttingerrors,hurtingthequalityoftheproduct.Operatorslistenforvibrationsandthenadjustthecuttingspeedtocompensate.inolder,slowermachinetools,thecuttingspeedwouldbereducedtoeliminatethevibrations,buttheamountoftimeneededtofinishtheproductwouldincreaseataresult.innewer,highspeedCNCmachines,increasingthecuttingspeednormallyeliminatesthevibrationsandreducesproductiontime.CNCoperatorsalsoensurethattheworkpieceisbeingproperlylubricatedandcooled,becausethemachiningofmetalproductsgeneratesasignificantamountofheat.Computercontrolprogrammersandoperatorstraininvariouswaysinapprenticeshipprograms,informallyonthejop,andinsecondary,vocational,orpostsecondaryschools.Duetoashortageofqualifiedapplicants,manyemployersteachintroductorycourses,whichprovideabasiccomputersandelectronicsalsoishelpful.Experiencewithmachinetoolsisextremelyimportant.Infact,manyentrantstotheseoccupationshavepreviouslyworkedasmachinistsormachinesetters,operators,andtenders.Personsinterestedinbecomingcomputercontrolprogrammersoroperatorsshouldbemechanicallyinclinedandabletoworkindependentlyanddohighlyaccuratework.Highschoolorvocationalschoolcoursesinmathematicstrigonometryandalgebra,blueprintreading,computerprogramming,metalworking,anddraftingarerecommended.Apprenticeshipprogramsconsistofshoptrainingandrelatedclassroominstruction.Inshoptraining,apprenticeslearnfiling,handtapping,anddowelfitting,aswellastheoperationofvariousmachinetools.Classroominstructionincludesmath,physics,programming,blueprintreading,CADsoftware,safely,andshoppractices.Skilledcomputercontrolprogrammersandoperatorsneedanunderstandingofthemachiningprocess,includingthecomplexphysicsthatoccuratthecuttingpoint.Thus,mosttrainingprogramsteachCNCoperatorsandprogrammerstoperformoperationsonmanualmachinespriortooperatingCNCmachine.Agrowingnumberofcomputercontrolprogrammersandoperatorsreceivemostoftheirformaltrainingfromcommunityortechnicalcolleges.LessskilledCNCoperatorsmayneedonlyacoupleofweeksofonthejobtraining.Computercontrolprogrammersandoperatorscanadvanceinseveralways.ExperiencedCNCoperatorsmaybecomeCNCprogrammers,andsomearepromotedtosupervisoryoradministrativepositionintheirfirms.Afewopentheirownshops.Computercontrolprogrammersandoperatorsshouldhaveexcellentjobopportunities.Duetothelimitednumberofpeopleenteringtrainingprograms,employersareexpectedtohavecontinuetohavedifficultyfindingworkerswiththenecessaryskillsandknowledge.JobgrowthinbothoccupationswillbedrivenbytheincreasinguseofCNCmachinetools.AdvancesinCNCmachinetoolsandmanufacturingtechnologywillfurtherautomateproduction,boostingCNCoperatorsproductivityandlimitingemploymentgrowth.ThedemandforcomputercontrolprogrammerswillbenegativelyaffectedbytheincreasinguseofsoftwarethatautomaticallytranslatespartandproductdesignsintoCNCmachinetoolinstructions.WhatisCNCCNCstandsforComputerizedNumericalControlandhasbeenaroundsincetheearly1970s.Priortothis,itwascalledNC,fornumericalcontrol.Whilepeopleinmostwalksoflifehaveneverheardofthisterm,CNChastouchedalmosteveryformofmanufacturingprocessinonewayoranother.Ifyoullbeworkingmanufacturing,itslikelythatyoullbedealingwithCNConaregularbasis.BeforeCNCWhilethereareexceptionstothisstatement,CNCmachinesreplaceorworkinconjunctionwithsomeexistingmanufacturingprocess.Takeoneofthesimplestmanufacturingprocesses,drillingholes,forexample.Adrillpresscanofcoursebeusedtomachineholes.Apersoncanplaceadrillchuckthatissecuredinthespindleofthedrillpress.Theycanthenmanuallyselectthedesiredspeedforrotationcommonlybyswitchingbeltpulleys,andactivatethespindle.Thentheymanuallypullonthequilllevertodrivethedrillintotheworkpiecebeingmachined.Asyoucaneasilysee,thereisalotofmanualinterventionrequiredtouseadrillpresstodrillholes.ApersonisrequiredtodosomethingalmosteverystepalongthewayWhilethismanualinterventionmaybeacceptableformanufacturingcompaniesifbutasmallnumberofholesorworkpiecesmustbemachined,asquantitiesgrow,sodoesthelikelihoodforfatigueduetothetediousnessoftheoperation.Anddonotethatweveusedoneofthesimplestmachiningoperationsdrillingforourexample.Therearemorecomplicatedmachiningoperationsthatwouldrequireamuchhigherskilllevelandincreasethepotentialformistakesresultinginscrapworkpiecesofthepersonrunningtheconventionalmachinetool.WecommonlyrefertothestyleofmachinethatCNCisreplacingastheconventionalmachine.Bycomparison,theCNCequivalentforadrillpresspossiblyaCNCmachiningcenterorCNCdrillingtappingcentercanbeprogrammedtoperformthisoperationinamuchmoreautomaticfashion.EverythingthatthedrillpressoperatorwasdoingmanuallywillnowbedonebytheCNCmachine,includingplacingthedrillinthespindle,activatingthespindle,positioningtheworkpieceunderthedrill,machiningthehole,andturningoffthespindle.HowCNCworksAsyoumightalreadyhaveguessed,everythingthatanoperatorwouldberequiredtodowithconventionalmachinetoolsisprogrammablewithCNCmachines.Oncethemachineissetupandrunning,aCNCmachineisquitesimpletokeeprunning.InfactCNCoperatorstendtogetquiteboredduringlengthyproductionrunsbecausethereissolittletodo.WithsomeCNCmachines,eventheworkpieceloadingprocesshasbeenautomated.Letslookatsomeofthespecificprogrammablefunctions.MotioncontrolAllCNCmachinetypessharethiscommonalityTheyallhavetwoormoreprogrammabledirectionsofmotioncalledaxis.Anaxisofmotioncanbelinearalongastraightlineorrotaryalongacircularpath.OneofthefirstspecificationsthatimplyaCNCmachinescomplexityishowmanyaxesithas.Generallyspeaking,themoreaxes,themorecomplexthemachine.TheaxesofanyCNCmachinearerequiredforthepurposeofcausingthemotionaneededforthemanufacturingprocess.Inthedrillingexample,these3axeswouldpositionthetoolovertheholetobemachinedintwoaxesandmachinetheholewiththethirdaxis.Axesarenamedwithletters.CommonlinearaxisnamesareX,Y,andZ.CommonrotaryaxisnamesareA,B,andC.Thesearerelatedtothecoordinatesystem.ProgrammableaccessoriesACNCmachinewouldntbeveryhelpfulifallitcouldonlymovetheworkpieceintwoormoreaxes.AlmostallCNCmachinesareprogrammableinseveralotherways.ThespecificCNCmachinetypehasalottodowithitsappropriateprogrammableaccessories.Again,anyrequiredfunctionwillbeprogrammableonfullblownCNCmachinetools.Herearesomeexamplesforonemachinetypemachiningcenters.AutomatictoolchangerMostmachiningcenterscanholdmanytoolsinatoolmagazine.Whenrequired,therequiredtoolcanbeautomaticallyplacedinthespindleformachining.SpindlespeedandactivationThespindlespeedinrevolutionsperminutecanbeeasilyspecifiedcanbeturnedoninaforwardorreversedirection.Itcanalso,ofcourse,beturnedoff.CoolantManymachiningoperationsrequirecoolantforlubricationandcoolingpurposes.Coolantcanbeturnedinandofffromwithinthemachinecycle.TheCNCprogramThinkofgivinganyseriesofstepbystepinstructions.ACNCprogramisnothingmorethananotherkindofinstructionset.Itswritteninsentencelikeformatandthecontrolwillexecuteitinsequentialorder,stepbystep.AspecialseriesofCNCwordsareusedtocommunicatewhatthemachineisintendedtodo.CNCwordsbeginwithletteraddresseslikeFforfederate,Sforspindlespeed,andX,YZforaxismotion.Whenplacedtogetherinalogicalmethod,agroupofCNCwordsmakeupacommandthatresembleasentence.TheCNCcontrolTheCNCcontrolwillinterpretaCNCprogramandactivatetheseriesofcommandsinsequentialorder.Asitreadstheprogram,theCNCcontrolwillactivatetheappropriatemachinefunctions,causeaxismotion,andingeneral,followtheinstructionsgivenintheprogram.AlongwithinterpretingtheCNCprogram,theCNCcontrolhasseveralotherpurposes.AllcurrentmodelCNCcontrolsallowprogramstobemodifiededitedifmistakesarefound.TheCNCcontrolallowsspecialverificationfunctionslikedryruntoconfirmthecorrectnessoftheCNCprogram,TheCNCcontrolallowscertainimportantoperatorinputstobespecifiedseparatefromtheprogram,liketoollengthvalues.Ingeneral,theCNCcontrolallowsallfunctionsofthemachinetobemanipulated.WhatisaCAMsystemForsimpleapplicationslikedrillingholes,theCNCprogramcanbedevelopedmanually.Thatis,aprogrammerwillsitdowntowritetheprogramarmedonlywithpencil,paper,andcalculator.Again,forsimpleapplications,thismaybetheverybestwaytodevelopCNCprograms.

注意事项

本文(外文翻译--计算机控制程序员与操作员该做什么.doc)为本站会员(英文资料库)主动上传,人人文库网仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对上载内容本身不做任何修改或编辑。 若此文所含内容侵犯了您的版权或隐私,请立即通知人人文库网([email protected]),我们立即给予删除!

温馨提示:如果因为网速或其他原因下载失败请重新下载,重复下载不扣分。

copyright@ 2015-2017 人人文库网网站版权所有
苏ICP备12009002号-5