外文翻译--基本的加工工序—切削，镗削和铣削.doc

1英文原文BASICMACHININGOPERATIONSMACHININGTOOLSHAVEEVOLVEDFROMTHEEARLYFOOT–POWEREDLATHEEGYPTIANSANDJOHNWILKINSON’SBORINGMILLTHEYAREDESIGNEDTOPROVIDERIGIDSUPPORTFORBOTHTHEWORKPIECEANDTHECUTTINGTOOLANDCUTTINGTOOLANDCANPRECISELYCONTROLTHEIRRELATIVEPOSITIONSANDTHEVELOCITYOFTHETOOLWITHRESPECTTOTHEWORKPIECEBASICALLY,INMETALCUTTING,ASHARPENEDWEDGESHAPEDTOOLREMOVESARATHERNARROWSTRIPOFMETALFROMTHESURFACEOFADUCTILEWORKPIECEINTHEFROMOFASEVERELYDEFORMEDCHIPTHECHIPISWASTEPRODUCTTHATISWORKPIECEINTHEFROMOFASEVERELYDEFORMEDCHIPISAWASTEPRODUCTTHATISCONSIDERABLYSHORTERTHANTHEWORKPIECEFROMWHICHITCAMEBUTWITHACORRESPONDINGINCREASEINTHICKNESSOFTHEUNCUTCHIPTHEGEOMETRICALSHAPEOFTHEMACHINESURFACEDEPENDSONTHESHAPEOFTHETOOLANDITSPATHDURINGTHEMACHININGOPRATIONMOSTMACHINEOPERATIONSPRODUCEPARTSOFDIFFERINGGEOMETRYIFAROUGHCYLINDRICALWORKPIECEREVOLVESABOUTACENTRALAXISANDTOOLPENETRATESBENEATHITSSURFACEANDTRAVELSPARALLELTOTHECENTEROFROTATION,ASURFACEOFREVOLUTIONISPRODUCED,ANDTHEOPERATIONISCALLEDTURNINGIFAHOLLOWTUBEISONTHEMA