数控技术(双语)

1数控技术（双语）NumericalControlTechnology董长双2013.7机械工程学院2Chapter1Introductiontonumericalcontrol1.1FundamentalsofNCtechnology1.1.1DevelopmenthistoryofNCLate1940s，JohnparsonsandFrankstulenputupNCideas.parsonscorporation（Traversecity,Michigan)theideaofusingcoordinatepositiondatacontainedonpunchedcardstodefineandmachinethesurfacecontoursofairfoilshapesprecision:±0.0015inch(±0.038mm)April1951,ContractwassignedbyMITandAirForce.March1952,ThefirstNCmachinewasdevelopedbyMIT.CincinnatiMillingMachineCo.verticalHydro-Telmillingmachine.Controllerconsisted292vacuumtubes.3Chapter1Introductiontonumericalcontrol4Chapter1Introductiontonumericalcontrol1954IndustryNCmachinewasdevelopedbyBendixCo.1959MachinecenterwasdevelopedbyKeaneyandTrecherCo.Machinecenter:MultifunctionNCmachinewithautomatictoolchangerandtoolstorage.1967FMSwasdevelopedbyMollinCo.Mollin24system,(24hr/day,16hrhumanworkerunattended)7machinetoolswascontrolledbyIBM1360/140computer.5Chapter1Introductiontonumericalcontrol1.1.2ConceptofNCandCNCGB8129-87定义：数字控制（NC）是用数字化信号对机床运动及其加工过程进行控制的一种方法，简称数控。数控机床（NCmachine)是采用了数控技术的机床或者说是装备了数控系统的机床。NChardwiredNCCNCComputernumericalcontrol6Chapter1Introductiontonumericalcontrol7Chapter1Introductiontonumericalcontrol8Chapter1Introductiontonumericalcontrol9Chapter1Introductiontonumericalcontrol10Chapter1Introductiontonumericalcontrol11Chapter1Introductiontonumericalcontrol12Chapter1Introductiontonumericalcontrol13Chapter1Introductiontonumericalcontrol14Chapter1Introductiontonumericalcontrol15Chapter1Introductiontonumericalcontrol16Chapter1Introductiontonumericalcontrol17Chapter1Introductiontonumericalcontrol18Chapter1Introductiontonumericalcontrol1.1.3BasiccomponentofNCmachinetoolsTheworkprocessofNCBasiccomponentsofaCNCmachinetool4412R121412PartprogramControlcomputerServo-driveunitMachinetoolPartdrawingPartInputmediaMachinecontrolunitServo-driveunitMachinetoolFeedbacktransducer19Chapter1Introductiontonumericalcontrol20Chapter1Introductiontonumericalcontrol1.2ClassificationofNCmachines1.2.1TypesofNCmotioncontrolsystem1.Point-to-pointcontrolsystem(Positioningcontrolsystem)2.Contouringcontrolsystem(Continuouspathcontrolsystem)21Chapter1IntroductiontonumericalcontrolInterpolationtwoormoreaxesmovessimultaneously1.linearinterpolation2.circularinterpolation3.helicalinterpolation4.parabolicinterpolation5.cubicsplineinterpolation22Chapter1Introductiontonumericalcontrol1.2.2TypesofNCservo-drivesystem1.Open-loopservodrive电机机械执行部件A相、B相C相、…f、nCNC插补指令脉冲频率f脉冲个数n换算脉冲环形分配变换功率放大Servo-motorisusuallySteppingmotor23位置控制调节器速度控制调节与驱动检测与反馈单元位置控制单元速度控制单元++--电机机械执行部件CNC插补指令实际位置反馈实际速度反馈Chapter1Introductiontonumericalcontrol2.half-Closed-loopservodriveACservomotororDCservomotorConvenienttoadjustHasagoodstability24位置控制调节器速度控制调节与驱动检测与反馈单元位置控制单元速度控制单元++--电机机械执行部件CNC插补指令实际位置反馈实际速度反馈Chapter1Introductiontonumericalcontrol3.Closed-loopservodriveACservomotororDCservomotor从理论上讲，可以消除整个驱动和传动环节的误差、间隙和失动量。具有很高的位置控制精度。由于位置环内的许多机械传动环节的摩擦特性、刚性和间隙都是非线性的，故很容易造成系统的不稳定，使闭环系统的设计、安装和调试都相当困难该系统主要用于精度要求很高的镗铣床、超精车床、超精磨床以及较大型的数控机床等。25Chapter1Introductiontonumericalcontrol1.2.3ApplicationofCNC1.Machinetoolapplicationturning,drilling,milling,grindingNClathe,NCboringmill,NCdrillpress,NCmillingmachine,NCgrindingmachine,machinecenter.MultifunctionNCmachineswithautomatictoolchangerandtoolstorage.2.Non-machinetoolapplicationPunchpress,sheetmetalbending,weldingmachine,thermalcuttingmachine(oxfuelcutting,lasercutting,plasmaarccutting),tubebendingmachine.26Chapter1Introductiontonumericalcontrol1.3FeaturesofNCmachineanditsapplicationareas1.3.1AdvantagesanddisadvantagesofNCMorecomplexpartgeometriesandgreateraccuracyparts1985“Toshibaevent”5axesNCmillingmachine5000000dollarssubmarinenoisereduced90%Norway波路斯塔特30岁1.3.2ApplicationareasforNCmachinetools27ManufacturingprocessanalyzeNCpartprogramOperationcardBACKSPACECTRLINSCRTABALT0SHIFTZENDWHOMETPgDnOPgUpJRSTE65“432？198:7YXVU[]SRPQNMKLIHFGDCABESC14''彩色显示器空运行Z轴锁定MST锁定任选程序段机床锁定快进+JOG-JOG主轴正转主轴停主轴反转急停超程解除循环驱动进给保持冷却液开关刀松/刀紧主轴修调16010进给修调16050403020100电源关开1自动方式选择回零手摇点动步进单段驱动器NC机床电源XYZA主轴超程报警手摇脉冲发生器2010090增量倍率1000101001坐标轴选择ZYXTraditionalmachiningNCmachiningcompareoftraditionalmachiningandNCmachiningChapter2NCpartprogramming2.1IntroductionPartgraphics→NCpartprogram28Chapter2NCpartprogramming2.1.1ThecontentsandstepsofNCprogramming1.Analyzingpartgraphicsanddeterminingthemanufacturingtechnologicalprocess.2.Correctlyselectingprogramoriginandcoordinatesystem.3.Calculatingnumericalvalues.4.Writingpartprogram.5.Fabricatingcontrolmedium.6.Verifyingpartprograms.29Chapter2NCpartprogramming常用的校验和试切方法：对于平面轮廓零件可在机床上用笔代替刀具、坐标纸代替工件进行空运转空运行绘图。对于空间曲面零件，可用蜡块、塑料或木料或价格低的材料作工件，进行试切，以此检查程序的正确性。在具有图形显示功能的机床上，用静态显示（机床不动）或动态显示（模拟工件的加工过程）的方法，则更为方便。上述方法只能检查运动轨迹的正确性，不能判别工件的加工误差首件试切(在允许的条件下)方法不仅可查出程序单和控制介质是否有错，还可知道加工精度是否符合要求。当发现错误时，应分析错误的性质，或修改程序单，或调整刀具补偿尺寸，直到符合图纸规定的精度要求为止。30Chapter2NCpartprogramming2.1.2ThemethodsofNCprogramming1.ManualpartprogrammingAlargenumberofuncomplicatedpartsareconstitutedonlybythesimplegeometricelementsofstraightlinesAndcircles.2.AutomaticprogrammingAPTla