Transcription of TYPES OF GRINDING WHEELS
1 GRINDING Abrasiveprocess MetalisremovedwiththehelpofROTATINGGRIND INGWHEEL Wheelsaremadeoffinegrainsofabrasivemater ialsheldtogetherbyabondingmaterialcalled aBONDT ypes of operations performed in cylindrical GRINDING GRINDING GRINDINGC onventionalgrindingmachinescanbebroadlyc lassifiedas:(a)Surfacegrindingmachine(b) Cylindricalgrindingmachine(c)Internalgri ndingmachine(d)Toolandcuttergrindingmach ineGRINDING MACHINESHORIZONTAL GRINDING Fulldepthandstockisremovedwithoneortwopa ssesatlowworkspeed Veryhighforcesaregenerated HighrigidityandpowerCYLINDRICAL GRINDINGSURFACE GRINDINGCENRELESS GRINDINGS urface GRINDING machine machine may be similar to a milling machine used mainly to grind flat surface Basicallytherearefourdifferenttypesofsur facegrindingmachinescharacterizedbythemo vementoftheirtablesandtheorientationofgr indingwheelspindles Horizontalspindleandreciprocatingtable Verticalspindleandreciprocatingtable Horizontalspindleandrotarytable VerticalspindleandrotarytableHorizontal spindle reciprocating table surface grinder Surface GRINDING (a) traverse GRINDING (b)
2 Plunge GRINDING Vertical spindle reciprocating table surface grinder Surface GRINDING in Vertical spindle reciprocating table surface grinder Cylindrical GRINDING machine ,tapered, centretype cylindrical grinder Classification of GRINDING MachinesTYPES OF GRINDING WHEELSS traightWheelThesearegenerallyusedforcyli ndrical,internal, , , 7 used in GRINDING of tools in 8. It is used for sharpening of circular or , of a ,toughnessandresistancetofractureuniform lyabrasivesareclassifiedintotwoprincipal groups:(a)Naturalabrasives,and(b) (solidquartz) , :Ifpercentageofaluminiumoxideismore,rang ingfrom75to95% ,34partsofpowderedcake,2patsofsalt,12par tsofsawdustinalongrectangularelectricfur naceofresistancetypeTherearetwotypesofsi liconcarbideabrasive,greengritwithapprox imately97%siliconcarbideblackgritwithapp roximately95% ,stoneandceramic,graycastiron,brass,bron ze,aluminiumvulcanizedrubber, ,ahydratedaluminumoxideclaycontainingsil ica,ironoxide.
3 Highcarbonandhighspeedsteelandtoughbronz eCoarse101214162024-Medium3036465460--Fi ne80100120150180--VeryFine22024028032040 0500600 Grits: The grain or grit number indicates in a general way the size of the abrasive grains used in making a wheel , or the size of the cutting teeth, since GRINDING is a true size is denoted by a number indicating the number of meshes per liner inch ( mm) of the screen through which the grains pass when they are graded following list ranging from very coarse to very fine includes all the ordinary grain sizes commonly used in the manufacture of :Theterm"grade" grade shall be indicated in all bonds and processes by a letter of the "soft"or"hard" ; :(a)Vitrifiedbond,(b)Silicatebond,(c)She llacbond,(d)Resinoidbond,(e)Rubberbond,a nd(f) Thisbondconsistsofmixtureofclayandwater.
4 Clayandabrasivesarethoroughlymixedwithwa tertomakeauniformmixture. Themixtureismouldedtoshapeofagrindingwhe elanddrieduptotakeitoutfrommould. Perfectlyshapedwheelisheatedinakilnjustl ikebrickmaking. Itthiswayclayvitrifiesandfusestoformapor celainorglassgrains. ,itissensitiveforheat,water, V , S ,finishingofchillediron,castiron,steelro lls, E , B . Rubberbondedwheelsaremoreresilientandhav elargerabrasivedensity. Associateddisadvantagewithrubberbondis,t hesearelesserheatresistant. Arubberwheelbondedwheelisdenotedbythelet ter R .OxychlorideBond Thesebondsareprocessedbymixingabrasivesw ithoxidesandchloridesofmagnesium. Themixtureismouldedandbakedinafurnacetog iveshapeofagrindingwheel. O .GLAZING AND LOADING, THEIR EFFECTS, CAUSES ANDREMEDIESW henthesurfaceofagrindingwheeldevelopsasm oothandshiningappearance, LoadingWhensoftmaterialslikealuminium,co pper,lead, ,knownasthestar-dresser,Dressing Forprecisionandhighfinishgrinding,smalli ndustrialdiamonds,knowninthetradeasbors, areused.
5 ,sinceonlythepointcanbeusedforcutting. Thisisdonebytheholderdownata15 angleandusinganewsurfaceeachtimethewheel isdressed. Goodsupplyofcoolantshouldbeusedwhendress ingwithadiamond, Truing:Truingistheprocessofchangingthesh apeofthegrindingwheelasitbecomeswornfrom anoriginalshape, , , , ,otherwisegroovesmaybecutintothewheelCUT TINGFLUIDSR ecommended cutting fluidsSolublemineraloilandpurewateraremi xedintheratioof1:40or50(dependinguponthe grindingwheel) iron or hardenedsteeloSoft steeloConnected carbide tools (using silicon wheel ) In India we use IOC Servocut oils as BALANCING OF GRINDING WHEELSURFACE ROUHGNESS OBTAINABLESUPER FINISHING
