数控技术专业英语 教学课件 作者 黄义俊 电子教案统一模板(数控)Unit2.ppt

《数控技术专业英语 教学课件 作者 黄义俊 电子教案统一模板(数控)Unit2.ppt》由会员上传分享，免费在线阅读，更多相关内容在应用文档-天天文库。

1、Unit2NC/CNCMachiningEquipmentLesson3TypesofCNCMachiningCenters2.1Lesson4CNCTurningCenter2.2ReadingMaterials3TheAdvantagesofCNCMachines2.3ReadingMaterials4TheDisadvantagesofCNCMachines2.42.1Lesson3TypesofCNCMachiningCentersMachiningcentersarethelatestdevelopmentinCNCtechnology.Thesesystemscome

2、equippedwithautomatictoolchangerswiththecapabilityofchangingupto90ormoretools.[1]Manyarealsofittedwiththemovablerectangularworktablescalledpallets.Thepalletsareusedtoautomaticallyloadandunloadworkpieces.Atasinglesetupmachiningcenterscanperformsuchoperationsasmilling,drilling,tapping,boring,an

3、dsoon.[2]Additionally,byutilizingindexingheads,somecentersarecapableofexecutingthesetasksonmanydifferentfacesofapartandatspecifiedangles.Turningcenterswithincreasedcapacitytoolchangersarealsomakingstrongappearanceinmodernproductionshops.[3]TheseCNCmachinesarecapableofexecutingmanydifferenttyp

4、esoflathecuttingoperationssimultaneouslyonrotatingpart.Inadditiontomachiningcentersandturningcenters,CNCtechnologyhasalsobeenappliedtomanyothertypesofmanufacturingequipment.Amongthesearewireelectricaldischargemachines(WEDM)andlasercuttingmachines.WEDMmachinesutilizeaverythinwireasanelectrode.

5、Thewireisstretchedbetweentworollersandcutsthepartlikeaband-saw.Materialisremovedbytheerosioncausedbyasparkthatmoveshorizontallywiththewire.CNCisusedtocontrolhorizontaltablemovements.WEDMmachinesareveryusefulforproducingmoldinserts,extrusionsandtrimdiesaswellasformtools.[4]LasercuttingCNCmachi

6、nesutilizeanintensebeamoffocusedlaserlighttocutthepart.Materialunderthelaserbeamundergoesarapidriseintemperatureandisvaporized.Ifthebeampowerishighenough,itwillpenetratethroughthematerial.Becausenomechanicalcuttingforcesareinvolved,laserscutpartswithaminimumofdistortionandhavebeenveryeffectiv

7、einmachiningslotsanddrillingholes.2.2Lesson4CNCTurningCenterCNCturningcenters,whileunlikechuckingcenters,aredesignedmainlyformachiningshaft-typework-pieceswhicharesupportedbyachuckandaheavy-dutytailstockcenter.Onfour-axismachines，twoopposedtu