Numerical-Control数控技术大学毕业论文外文文献翻译及原文

毕设计论文）外文献翻译文献、资中文题目：控技术文献、资英文题目：Control文献、资来源：文献、资发表（出版日期：院（部专班姓学

业：级：名：号：指导教师翻译日期2017.02.14NumericalControlNumerical(N/C)aformofinwhichprocessingequipmentisofnumbers,lettersandothersymbols.Thenumbers,letters,symbolscodedinanappropriateprogramofinstructionsaparticularworkpartjob.Whentheprogramofinstructionsbechanged.capabilitytoprogramiswhatN/Cforlow-volumeandItistomakealterationsofprocessingarebasictypesofnumericallycontrolledmachinepoint—to—continuouscalledPoint—to—machinesuseunsynchronizedmotors,withthatpositionofthemachiningbeassureduponcompletionofwhileonlymotorisrunning.oftypeprincipallyforstraight—cutsforTheN/Cconsiststhefollowingreaderwiththeunit,the—cuttingtooltypeofN/CDatainput,alsocalled“manto—controllink”,maybeprovidedthemachinetoolentirelybymeans.Manualmethodsusedthesourceofarelativelysmallnumberofinputs.Examplesofoperatedarekeyboardpushbuttons,switches,thumbwheelselectors.arelocatedonaconsolenearaledevicesusuallytosynchronization-typepotentiometer.cases,ofaredigitalinputManualinputthatsetcontrolseachoperation.ItaslowprocessisseldomjustifiedexceptinmachiningapplicationsinspecialInpracticallyinformationisautomaticallytocontrolunitthemachinebycards,byEight

—papercommonlyformofdatainputforN/CcodedinstructionsonofsectionsofpunchedholesEachamachinefunction,amachiningoraoftheN/Cprogramonofanofblocks,resultinginallonreelsmotion-picturefilm.onrelativelybecontinuouslybyjoiningendsoftheformainstalled,tapeiswithoutIncase,simplyPunchedalepreparedontypewriterswithtape—attachmentsorinconnectedcomputerrarelymaybeinitiallybythepartprogrammer,incardcompilation,aoftothetapeduringhandling,etc.SeveraltrialrunsarenecessarytoremoveallanacceptableworkingWhiledataontheisautomatically,stepsdoneBeforecodedtapemaybeprepared,oftenwithaorprocessengineer,theappropriateN/Cmachinetool,kindofmaterialtobecalculatethespeedsuponthetypeoftoolingneeded.dimensionsonprintcloselyexaminedasuitablezeroreferencepointfromtostarttheAprogramthenwrittenwhichcodedinstructionsthesequenceofoperationsthemachinerequiredtotocutparttodrawingTheunitreceivesstoresallcodeduntilcompleteblockofinformationbeenItthentheinstructionandthemachinetooltherequiredThefunctionofunitmayittoactionofdialdigititistheentirebeendialed,becomesactivatedandiscompleted.Siliconinthereaderonunit,lightasitthroughtheinthemovingThelightconvertedtowhichisamplifiedtostrengthenThesignalsintheunit,whereactuationrelayedtomachineSomedevicesarecapabletosecond.Highratesnecessarytomaintaincontinuous—toolmotion;otherwisebegeneratedbyonpartduringoperations.Thereadingdeviceofblocksratethansystemprocessdata.AfeedbackisausedonsomeN/CtocompensateforerrorsthetheofofmachineAnN/Cmachinewithkindofadirectfeedbackcheckingdevicewhatissystem.controlisaccomplishedawhich,duringtheoperation,thepositionofrelaysinformationbacktocontrolunit.receivedtoonbetweenthemInancalledanopenloopmachineispositionedsolelybysteppingmotorintoaarethreebasictypesoffollows:orControlInpoint-to-pointthemachinetooltable,etc.)movedThespeedofbetweenisonlythecoordinatesoftheofthecontrolled.Thistypeofcontrolissuitablefordrillpressessomeboringmachines,whereboringbeperformedlocationsontheworkorLinearControlsystemsaretomovecuttingtooltoofofthemachinetoolacontrolledsuitableformachining.Itisnormallymoveinonedirectionsocutsonnotformillingonlybemachinedorlathessurfacesparallelortotheaxiscantypeofmotionisaslinearcontrolacontrol.Machineswiththisformofcontrolarealsocapablepoint-to-pointContinuousPathorContouringControlIncontinuouscontrolthemotionsoformoreofmachineaxesarecontrolledsimultaneously,thatpositionvelocityofthecanbetoolInwaycurvessurfacesbemachinedatcontrolledfeedrate.Itofinterpolatorinthecontrollertodetermineoftheindividualcontrolledaxesofmachinestoproducetypeoftoascontinuousorafullaxisofcontrol.SomeconcerningmotionsforNChasbeenexample,areasfour-orfive-orevensix-axisForverticalmachinethreeoffairlyobvious,thesebeingtheusualX,YZdirections.AfourthfifthaxiswouldimplyformrotarytabletoindexworktoprovideangularmotionoftheworkThus,inNCanaxisofcontrolanycontrolledmotionofmachine(spindles,tables,Acomplicationuseoftermhalf-axisofforexample,manymillingmachinestoasThismeansthatcontinuouscontrolformotions(axes)andonlylinearcontrolfortheAppliedverticalmillingmachines,controlmeanscontouringintheX,YplanelinearmotioninZdirection.WithhavetobewitharoundthedifferentWithansamemachinecouldbecalleda2CLmachine(CforLforlinearcontrol).amachinewithcontinuouscontrolinX,Y,Zdirectionsbebemachineora3cSimilarly,usuallytwoorTheofprecisionalmostentirelyupontheofscrewtheofmachinestructure.thisthereisnoself-correctingactionfeedbackoftheIneventanunexpectedmalfunction,theoutpulsesofelectricalcurrent.If,forexample,onanN/Cmillingwerenoresponsewouldbetosteppingmotorsnotvariations,N/Carepermittostallwhentheresistingexceedsthemotortorque.Otherareinuse,whichinofpossibilityofthemachinestructureortosystem,alewith—steppingmotors.Inthemotorshavesufficientcapacityto“overpower”thesystemtheeventofalmostanycontingency.Theoriginalusedthe—system.Ofopenloop,loopand,aconsequence,isexpensive.Initially,openloopsystemswerealmostentirelyforapplicationsbecauseofpreviouslyassociatedwithelectricsteppingadvancesinofelectrosteppingmotorsledtoincreasinglymachine数控技术数控是可编程自动化技术的一种形式通过数字字母和其他符号来控制加工设备数字字母和符号用适当的格式编码为一个特定工件定义指令程序当工件改变时指令程序就改变这种改变程序的能力使数控适合于中小批量生产，写一段新程序远比对加工设备做大的改动容易得多。数控机床有两种基本形式点位控制和连续控制(也称为轮廓控制)点位控制机床采用异步电动机因此主轴的定位只能通过完成一个运动或一个电动机的转动来实现。这种机床主要用于直线切削或钻孔、镗孔等场合。数控系统由下列组件组成数据输入装置带控制单元的磁带阅读机反馈装置和切削机床或其他形式的数控设备。数据输人装置，也称“人机联系装置用人工或全自动方法向机床提供数据人工方法作为输人数据唯一方法时只限于少量输入人工输入装置有键盘拨号盘按钮开关或拨轮选择开关这些都位于机床附近的一个控制台上。拨号盘通常连到一个同步解析器或电位计的模拟装置上大多数情况下、开关和其他类似的旋钮是数据输入元件人工输入需要操作者控制每个操作这是一个既慢又单调的过程，除了简单加工场合或特殊情况，已很少使用。几乎所有情况下息都是通过卡片纸带或磁带自动提供给控制单元。在传统的数控系统中八信道穿孔纸带是最常用的数据输入形式纸带上的编码指令由一系列称为程序块的穿孔组成每一个程序块代表一种加工功能一种操作或两者的组合纸带上的整个数控程序由这些连续数据单元连接而成带有程序的长带子像电影胶片一样绕在盘子上对较短的带子上的程序可通过将纸带两端连接形成一个循环而连续不断地重复使用带子一旦安装好就可反复使用而无需进一步处理。此时，操作者只是简单地上、下工件。穿孔纸带是在带有特制穿孔附件的打字机或直接连到计算机上的纸带穿孔装置上做成的带制造很少不出错，错误可能由编程、卡片穿孔或编码、纸带穿孔时的物理损害等形成。通常，必须要试走几次来排除错误，才能得到一个可用的工作纸带。虽然纸带上的数据是自动进给的但实际编程却是手工完成的在编码纸带做好前编程者经常要和一个计划人员或工艺工程师一起工作选择合适的数控机床，决定加工材料，计算切削速度和进给速度，决定所需刀具类型，仔细阅读零件图上尺寸定下合适的程序开始的零参考点然后写出程序清单其上记载有描述加工顺序的编码数控指令，机床按顺序加工工件到图样要求。控制单元接受和储存编码数据直至形成一个完整的信息程序块然后解释数控指令，并引导机床得到所需运动。为更好理解控制单元的作用将它与拨号电话进行比较每拨一个数字，就储存一个，当整个数字拨好后，电话就被激活，也就完成了呼叫。装在控制单元里的纸带阅读机通过其内的硅光二极管检测到穿过移动纸带上的孔漏过的光线将光束转变成电能并通过放大来进一步加强信号然后将信号送到控制单元里的寄存器，由它将动作信号传到机床驱动装置。有些光电装置能以高达每秒个字节的速度阅读，这对保