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Lip angle: Angle between the top face and the flank of the tool.It is also known as angle of keenness. Strength of cutting edge or point of the tool is directly affected by this angle.Larger thel lip angle stronger will be the cutting edge and vise versa.<br>Lip angle varies inversely as the rake angle.<br>Back rake angle: There is also known as Top rack angle. It is the angle between face of tool and a plane parallel to base of tool. The inclination is given from nose along with length of tool and towards the shank. The angle may be positive or negative .<br>side rake angle: The angle between face of
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Cuttingtool • Itisanytoolthatisusedtoremovematerialfrom theworkpiecebymeansofsheardeformation. • Itfrequentlyreferstoasatoolbit. • Theymustbemadeofamaterialharderthanthe materialwhichistobecut,andthetoolmustbe abletowithstandtheheatgeneratedinthemetal cuttingprocess.
Differenttypesofcuttingtools Accordingtothenumberofcuttingedgethecutting toolsbroadlyclassifiedinto Singlepointcuttingtool Multipointcuttingtool
Singlepointcuttingtool • Thistypeoftoolshasonlyonecuttingedgetoremoveexcess materialfromtheworkpiece.Theymaybeleft/righthanded accordingtothesideofcuttingedgewhenviewingfromtheend point. • Example:toolsusedinlathes,planers,shapersandboringmachines • Multi-pointcuttingtool • .Theyhavemorethanonecuttingedgetoremoveexcess material.Itconsideredasaseriesofsinglepointcuttingedgeonthe peripheryandduringoperationeachcuttingedgeindependently cuttheworkpiece. • Example:Millingcutters,grindingwheels,drills,reamer,broaches
Typesofcuttingtool • Accordingtotheconstructionofcuttingtool: • Solid typetools: Groundtypeandforgedtypetools • Groundtype-Cuttingedgeisformedbygrindingtheendoftool • Forgedtype–Roughforgingisusedbeforehardeningandgrinding toformacuttingedge. • Tippedtypetools:Tippedtypeandinserttype • Tippedtype–High-gradematerialtoolsareusuallyprovidedbythis method.Thecuttingedgeisformedintheformofthesmalltip,whichis brazedtotheshankoflowergradematerial. • Insertorbittype-Atoolbitofhigh-gradematerialisformedinthe formofpolygonalshape,andthenitismechanicallyheldbythecutting toolholder.Insertscannotreshape,soitisdiscardedwhenallcutting edgeswearout.Thennewbitsareinsertedintothetoolholder.
Tippedtypecuttingtool • Insertorbittypecuttingtool
Typesofcuttingtool • Accordingtothequalityofmachiningoperation • Roughingtools:Thistypeoftoolsused forremovingalargeamountof materialintheformofathicklayerofchips. • ii)SurfaceFinishingtools:Thistypeoftoolsusedformetalremovalinthe formofasmallsectionofthechipwithhighcuttingspeedtoachievegood finishing. • Withhelpof singlebroachingtool,roughing&surfacefinishingboth operationcanbedone
Typesofcuttingtool • Accordingtothemotionofcuttingtool • Linearmotiontools: • Lathetools,Boringtools,Broachingtools,Planingtools,Shapingtools,etc. • Rotarymotiontools: • .Millingcutters,Grindingwheels,etc. • LinearandRotarytools: Drills,Honingtools,etc.
Geometryofcuttingtool • Shank:Mainbodyoftool,itispartoftoolwhichisgrippedintoolholder • Face:Topsurfaceoftoolb/wshank andpointoftool.Chipsflowalong thissurface. • Point:Wedgeshapedportionwherefaceandflankof toolmeet. • Heel:Itistheintersectionoftheflankandthebaseof thetool
Flank:Portiontoolwhichfacesthework.Itis surfaceadjacenttobelowthecuttingedgewhen toolliesinahorizontalposition. • Base :Itistheportionoftheflankthatliesoppositetothe topfaceoftheshank • Nose:The intersectionpointofmajorcuttingedgeand minorcuttingedgeiscalledNose. • Cuttingedge: Theedgeonthetoolwhichremoves materialsfromtheworkpieceiscalledcuttingedges.It liesonthefaceofthetool. • endcuttingedge • sidecuttingedge
Lipangle:Anglebetweenthetopfaceandtheflankofthe tool.Itisalsoknownasangleofkeenness.Strength ofcutting edgeorpointofthetoolisdirectlyaffectedbythisangle.Larger thellipanglestrongerwillbethecuttingedgeandviseversa. • Lipanglevariesinverselyastherakeangle. • Backrakeangle:ThereisalsoknownasToprackangle.Itis theanglebetweenfaceoftoolandaplaneparalleltobaseof tool.Theinclinationisgivenfromnosealongwithlengthoftool andtowardstheshank.Theanglemaybe positiveornegative. • siderake angle:Theanglebetweenfaceoftoolandline perpendiculartoflankoftool. The slopeisgiventheface(or) tooltopposition.Theinclinationisgiventowardsthesideofthe tool.
Positiverakeangle: • Thepositiverakeangletoolhassharpcutting edgeandthecuttingforcerequiredisless in positiverakeangletool.So,thepower requirementduringmachiningisalsoless.This typeoftoolusedinmachiningofsoft material.Positiverakeanglealsohelpin achievingbettermachinability. • Zerorakeangle • Zerorankeangleisintermittentofpositiveand negativerakeangle.Itprovideadvantage anddisadvantagesofbothtosomeextent. • Zero rakeangleisveryeasytodesignand calculationforestimatingmachiningforceis veryeasyinzerorakeangle.
NegativerakeAngle • Usedformachininghardmaterial. • Highcuttingforcerequiredinmachining. • Usedforheavyandinterruptedcuts • Largerlipangle,hensestrongertool. • Effectsofsiderakeangle:- • Duringthemachiningoperationthechipcurlingor amountofchipbendsdependsuponthesiderakeangle. Ifthesiderakeangleislarger,cutandbendingofchip andpowerrequirementwillbedecreased.Hencethat providingbettersurfacefinishofmachiningsurface.
Sidereliefangle:Itistheanglethatpreventstheinterference asthetoolentersthematerial.Itistheanglebetweenthe portionofthesideflankimmediatelybelowthesideedge andalineperpendiculartothebaseofthetoolmeasuredat rightanglestotheside.Itisincorporatedonthetoolto providereliefbetweenitsflankandthework piecesurface. • Sometimeextrasideclearanceisalsoprovidedonthetool thatisalsoknownassideclearanceangle.Itisthesecondary angledirectlybelowtheside reliefangle. • Endrelief angle:Itistheanglethatallowsthetooltocut withoutrubbingonthework-piece.Itisdefinedastheangle betweentheportionoftheendflankimmediatelybelowthe cuttingedgeandalineperpendiculartothebaseofthetool, measuredatrightanglestotheflank.Sometimeextraend clearanceisalsoprovidedonthetoolthatisalsoknownas endclearanceangle.Itisthesecondaryangledirectlybelow theendreliefangle.