2023年車(chē)輪和輪胎基本知識(shí)

千里之行，始于足下讓知識(shí)帶有溫度。第第2頁(yè)/共2頁(yè)精品文檔推薦車(chē)輪和輪胎基本知識(shí)

Wheels

Demandsofthewheels

?Lowweight,

?Largeinnerdiameterforlargebrakediscs,

?Highformstabilityandelasticity,

?Goodheatdissipation(frictionalheat),

?Simplechangeofthewheelsandtyreswithtyredamages.

Assemblyofawheel

Thewheelconsistsofthewheelandthewheeldiscwithcentralboringandboltholes.Insteadofthewheeldisc,awheelstarispresentorwheelsorawheelwheresteelspokesareconnectedwiththehub.

Thewheelisconnectedontheflangeofthewheelhubwhichispivotedpivotablewiththesteeringknuckleadaptorend,withwheelnutsorwheelbolts.Otherthanthat,thebrakediscsorthebrakedrumsaremountedfirmusingboltstotheflangeofthewheelhub.

Withopenlyingbearings,thehubcovertakesoverthetaskofprotectingthebearingandisafatstorageforthefatreservesatthesametime.Rims

Therearerimswhicharefittedfirmwiththewheeldiscandthosewhichcanberemoved.Otherthanthat,undividedrimsaredifferedthroughrims(dropcentrerims)andmultiplepartrims(Trilex),whichfindtheirusewithLightandHeavyGoodsVehicles.

Dropbaserims

Forpassengervehicles,generallyundivideddropcentrerimsareused.Theyarerivetedorweldedfestwiththewheeldiscorarecastedorforgedfromalloymetalswiththewheeldiscasonepiece.

Thecrosssectionoftherimcanbesymmetricalorunsymmetrical.

AT_40_0014

1.Rimflange

2.Rimopening

3.Rimdiameter

4.Dropcentrerim

5.Rimbedseat

6.Hump

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3

5

4

1

6

Humprims

Whenusingtubelessbeltedtyres,dropcentreringrimshavetobeusedofwhichtherimshoulder,neartothedropcentrerim,hasacirculatingroundincrement=Hump(H).

Iftheincrementisnotroundandisflattenedthenonetermsthisasa

Flat-Hump(FH).Bothoftheseshouldpreventthatthetyrebulgeswhendrivingwithhigherspeedsincurvesthattherimshoulderisnotpressedintothedropcentrerimthroughthehighlateralforces.Withtubelesstyres,theaircanescapequicklysothatanaccidentcouldbetheresult.

Measurementsandtermsontherims

ThesedetailsareNormed.Therimtermsarestampedineachwheelbythemanufacturer.Theyconsistprincipallyfrom2dimensions,therimopening(a)ininchesandtherimdiameter(D)ininches.Bothdimensionsareseparatedwithan”x”indropcentrerims.

Codedlettersaftertherimdiametergiveinformationaboutthetypeofrim.Press-indepth

Thisisthedimensionfromthemiddleoftherimtotheinnercontactsurfaceofthewheeldisc.

Throughweldingtherimandwheeldisc,thepress-indepthcanbechosen.Therefore,therimisdeterminedforacertainchassisasthepress-indepthrelatedirectwiththekingpinoffset.

Positivepress-indepth

Theinnercontactsurface,basedonthemiddleoftherim,isdisplacedtotheoutersideoftherim.

Negativepress-indepth

Theinnercontactsurfaceisdisplacedtotheinnersideoftherim.Throughusingtherimwithsmallerpositiveornegativepress-indepths,thespurwidth

ofthevehiclecanbewidened.

AT_40_0001

AT_40_0015

Example6?Jx13H

6?=RimopeninginInches

J=CodeletterforthemeasurementsoftherimflangeX=undivideddropcentrerim

13=Rimdiameterininches

H=oneHumpontheoutershoulder

Tyres

DemandsoftheTyres

?Absorptionoftheweightofthevehicle,

?Absorptionofsmallroadsurfaceimpacts,

?Transformationofdriving,brakeandlateralforces,

?Loweffortwhenparking,

?Lowrollingresistancethereforelowerinnerfrictionandheatdevelopment,

?Sufficientlengthoflife,

?Alownoiseandvibrationrolling.

Assembly

Valve,innertubeandtherimbandarecomponentsofatyre.Therimbandisonlyusedinmopedsandvehicleswherethetubehastobeprotectedagainstthenippleheadsofthespokes.Theinnertubehastocomplywiththesizeofthetyre.

Thetyreconsistof:

?Carcass(Fabriccarcass),

?Belt(principallybyradialtyres),

?Intermediateconstructionwithcontactsurface(Protector),

?Bulgeswithinlayingsteelwirecore.

AT_40_0008

1.Contactsurface

2.Intermediate

construction

3.Siderubber

4.Valve

5.Bulge

6.Belt

7.Airtightrubberlayer

8.Fabriccarcass

(Carcass)

9.Rimflange

10.Hump

11.Rimshoulder

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11

6

8

10

9

1

7

2

5

4

3

Carcass

ThisisbasedongummedcordthreadswhicharegenerallymanufacturedfromRayon,Steel,PolyesterorAramid.Thethreadsarelayeredovereachotherandthisiseitherinadiagonalleadingangletothedrivingdirection(Diagonaltyre)orrightangulartothedriving6direction(Radialtyres).

Whenwinding,thethreadsarewoundaroundtwosteelrings(Bulgecores)andarethenanchoredthroughvulcanisation

Intermediateconstruction

Thisconsistsofmultiplefibrelayersandrubberpadding,absorbsimpactsandprotectsthecarcass.

Belt

Thisconsistsofmultiplelayersofrubberembeddedsteelwires,textilethreads,nylonoraramidfibres.Thebeltliesabovethecarcassandisfinishedsothatthewiresorfibrescross.Thebeltcanbefoldedwithhighspeedtyreswhichraisesthestability.Contactsurface

Thisisprovidedwithaprofile.Thelongitudinalprofilegivesthetyrealateralholding,thetransverseprofiletransfersthedrivingforce.Thelateralshouldersofthecontactsurfacecreateatransfertothesidewallwhichprotectsthecarcass.

Aquaplaning

Onawetroadsurface,awaterwedgecanbecreatedbetweenthetyresandthesurfaceoftheroadwhichliftsthevehicleanditisthenunabletobecontrolled.ToreducethedangerofAquaplaning,theprofilegrooveshavetohaveaminimaldepthsothattheycanabsorblotsofwater.

Otherthanthat,theyneedcertainformssothatthewatercanflowoutwardswithahighspeedandoverashorttime.Thedrivingspeedishastobeadjustedtothestateoftheprofile,thewaterdepthandtheroadsurface.

AT_40_00091.FoldedAramidbelt

2.Carcass

3.Bulgecore

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Dimensionsandtermsofthetyres

Tyresize

Thisisdeterminedthroughthedetailsof2dimensions:Tyrewidthinmm;Rimdiameterininches.

Crosssectionratio

Thedifferenttyrecategories,e.g.balloontyres,lowcrosssectiontyres,beingabletorecognisehowtherelationshipofthetyreheightandtyrewidthisdetermined.Thetyretermisgiveninpercent.

Moderntyreshaveagreaterwidththanheight.Iftheheightofthetyrevaluese.g.80%ofthewidththentheheight:width=0,8:1.Asthepercentvalueisusedinthetyreterms,onewouldsay80ertyre.

Speedcategories

Theydifferthetyresofapassengervehiclethanthatofacommercialvehicleagainsttheirregisteredtopspeed.EveryhighspeedisRegisteredwithaletter.Tyreloadcarryingcapacity

Thesedifferthetyresagainsttheirstresscapability.Fortheterminginthepast,thePRnumberwasused.Thespecification4PR(PlyRating)meantthatbecauseofthestabilityofitscarcass,thatitcouldbeloadedlikeatyrewith4layersofcottonthread.ThePRnumberisnotactualanymoreandhasbeenreplacedbyaLoadIndexLI.

ThisisthecodenumberwhichshowsthehighestcarryingcapacityofthetyreThetyrecarryingcapacityisaccordingtothevehiclemanufacturerinconnectionwiththehighestspeed,airpressureanddownfall.

Exampleforthetyreterms

Balancing

Theweightofaturningtyreisneverthesameoverthecompletecircumfer-ence.

Onthepointwherethegreatermassappearsiswheretheunbalancingtakesplace,whichmeansthatacentrifugalforceiscreatedandthegreatertheyarethegreatertheturningmomentis.

Staticunbalance

Ife.g.throughblockingbrakes,apointonthecontactsurfaceofthetyreisrubbedoff,thenontheoppositepositionallargemassofacentrifugalforcewhich,withhigherspeeds,canleadtothejumpingofthetyreontheroadsurface.

Th