平面磨床中英文外文翻译文献Word格式.docx

1、usedabrasivemachining process inwhicha spinning wheelcoveredinroughpa rticles（grinding wheel）cuts chips ofmetallicornonmetallicsubsta nce from a workpiece,makinga fa c e o f it fla t o r s m o o th.ProcessSurfa cegrindingis the mostcommonofthe grinding operations.Itis a finishing processtha tuses a

2、rotating abrasivewheeltosmooththe flatsurface ofmetallicornonmetallicmaterials togivethem a more refinedlookortoattaina desiredsurface fora functiona lpurpose.The surface grinderis composedofa nabrasivewheel,a workholding device knownasa chuck,a nda reciprocating ta ble.The chuckholds the ma teria l

3、inpla ce while itis beingw o rke d o n . It c a n d o th is o n e o f tw o w a y s : m e ta llic p ie c e s a re h e ld in p la c e b y a m a g n eticchuck,while nonmetallicpieces are heldinpla ce by vacuum ormecha nicalmea ns.Factorstoconsiderinsurfacegrinding are the ma terialofthe grinding wheela

4、ndthematerialofthe piece being workedon.Typica lworkpiecema teria ls include castirona ndminorsteel.These twomaterials donttendtoclog the grinding wheelwhile being processed.Othermaterials are a luminum,stainlesssteel,brass andsome pla stics.Whengrinding athightemperatures,the materia lte n d s to b

5、 e c o m e w e a ke n e d a n d is m o re in c lin e d to c o rro d e . Th is c a n a ls o re s u lt in a lo ssofmagnetism inma teria ls where this is a pplicable.The tolera nces thatare normallyachievedwithgrindingare 2 104 inches fora grinding a fla tmaterial,and3 104 inches fora parallelsurface.T

6、he grinding wheelis notlimitedtojusta cylindricalshape,butcanhavea myriadofoptions thatare usefulintransferring differentdesigns tothe objectbeing workedon.Whensurfacegrinding anobject,one mustkeepinmindthatthe shape ofthe wheelwillbe transferredtothe materialofthe objectlike a mirrorimage.S p a rk

7、o u t is a te rm u s e d w h e n p re c is io n va lu e s a re s o u g h t a n d lite ra lly m e a n s u n til thesparksare out（nomore）.Itinvolves passing the workpiece underthe wheel,withoutresetting the depthofcut,more thanonce andgenerallymultiple times.This ensures thatany inconsistencies inthe

8、machine orworkpiece are eliminated.EquipmentSurface Grinderwithelectromagneticchuck,insetshows a Manua lmagnetic chuckAsurface grinderis a ma chine toolusedtoprovide precisiongroundsurfaces,eithertoacriticalsize orforthe surfa ce finish.Thetypica lprecisionofa surface grinderdepends onthe type a ndu

9、sa ge,however+/-0.002 mm （+/-0.0001）shouldbe a chievable onmostsurface grinders.The machine consists ofa table thattraverses bothlongitudinallyandacross the face ofthewheel.The longitudinalfeedis usuallypoweredby hydraulics,a s maythe cross feed,howevera ny mixture ofhand,electricalorhydraulicmaybe

10、useddepending ontheultimateusageofthe ma chine （i.e.:production,workshop,cost）.The grinding wheelrotates inthe spindle hea dandis alsoadjustable forheight,by any ofthe methodsdescribedpreviously.Modernsurface grinders are semi-automated,depthofcutandspark-outmay bepresetas tothe numberofpasses andon

11、ce setupthe ma chiningprocess requires verylittle operatorintervention.Depending onthe workpiece material,the workis genera lly heldby the use ofa magneticchuck.This may be eitheranelectromagneticchuck,ora manuallyoperated,permanentmagnettype chuck;bothtypes are showninthe firstimage.Themachine has

12、provisionforthe a pplicationofcoolantas wellas the extra ctionofmetaldust（metalandgrinding particles）.Types ofsurfa ce grindersHorizontal-spindle （peripheral）surface grinders The periphery（flatedge）ofthe wheelis incontactwiththe workpiece,producing the flatsurface.Peripheralgrinding is usedinhigh-pr

13、ecisionworkonsimple fla tsurfaces;tapers orangledsurfa ces;slots;fla tsurfacesnexttoshoulders;recessedsurfaces;andprofiles.Vertical-spindle （wheel-fa ce）grinders The face ofa wheel（cup,cylinder,disc,orsegmentalwheel）is usedonthe fla tsurface.Wheel-face grinding is oftenusedforfastmaterialremoval,but

14、somema chines canaccomplishhigh-precisionwork.The workpieceis heldona reciprocating table,whichcanbe variedaccording tothe task,orarotary-tablema chine,withcontinuous orindexedrotation.Indexing allows loading orunloading one stationwhile grinding operations are being performedonanother.Discgrindersa

15、nddouble-discgrinders Discgrinding is similartosurface grinding,butwitha largercontactarea betweendisc andworkpiece.Disc grinders are availa ble inbothverticalandhorizontalspindle types.Double disc grinders workbothsides ofa workpiecesimulta neously.Disc grinders are capable ofachieving especia llyfine tolerances.Grinding wheels forsurface grindersAluminumoxide,siliconcarbide,diamond,andcubic boronnitride （CBN）are fourcommonly usedabrasivematerials forthe surface ofthe grinding wheels.Ofthesematerials,aluminum oxide is the mostcommon.Because ofcost,diamonda ndCBN