数控技术---外文翻译.doc

NUMERICALCONTROLNUMERICALCONTROLN／CISAFORMOFPROGRAMMABLEAUTOMATIONINWHICHTHEPROCESSINGEQUIPMENTISCONTROLLEDBYMEANSOFNUMBERS，LETTERS，ANDOTHERSYMBOLS．THENUMBERS，LETTERS，ANDSYMBOLSARECODEDINANAPPROPRIATEFORMATTODEFINEAPROGRAMOFINSTRUCTIONSFORAPARTICULARWORKPARTORJOB．WHENTHEJOBCHANGES，THEPROGRAMOFINSTRUCTIONSISCHANGED．THECAPABILITYTOCHANGETHEPROGRAMISWHATMAKESN／CSUITABLEFORLOWANDMEDIUMVOLUMEPRODUCTION．ITISMUCHEASIERTOWRITEPROGRAMSTHANTOMAKEMAJORALTERATIONSOFTHEPROCESSINGEQUIPMENT．THEREARETWOBASICTYPESOFNUMERICALLYCONTROLLEDMACHINETOOLSPOINTTOPOINTANDCONTINUOUSPATHALSOCALLEDCONTOURING．POINTTOPOINTMACHINESUSEUNSYNCHRONIZEDMOTORS，WITHTHERESULTTHATTHEPOSITIONOFTHEMACHININGHEADCANBEASSUREDONLYUPONCOMPLETIONOFAMOVEMENT，ORWHILEONLYONEMOTORISRUNNING．MACHINESOFTHISTYPEAREPRINCIPALLYUSEDFORSTRAIGHTLINECUTSORFORDRILLINGORBORING．THEN／CSYSTEMCONSISTSOFTHEFOLLOWINGCOMPONENTSDATAINPUT，THETAPEREADERWITHTHECONTROLUNIT，FEEDBACKDEVICES，ANDTHEMETALCUTTINGMACHINETOOLOROTHERTYPEOFN／CEQUIPMENT．DATAINPUT，ALSOCALL