车辆与轮胎之均一性Uniformity of vehicle and tireWord下载.docx

车辆与轮胎之均一性Uniformity of vehicle and tireWord下载.docx

《车辆与轮胎之均一性Uniformity of vehicle and tireWord下载.docx》由会员分享，可在线阅读，更多相关《车辆与轮胎之均一性Uniformity of vehicle and tireWord下载.docx（16页珍藏版）》请在冰点文库上搜索。

Thesuspensionactsonthecarbody,causingtheinevitableverticaljump

Between10~20Hz.

Toavoidthisvibration,theaccuracyoftheaxleeccentricitytothecenterofthewheelisgenerated

Asofabout0.1mminthefanring,nomatterhowhardthemanufacturingofTIREandonthecar

Thecenterisconsistent,andsincetheTIREisanelastomer,itisdifficulttoguaranteetheaccuracyofthedimensions

Of.

Eventhoughthedimensionsareaccurate,theverticalspringrateateachpointofthetirecircumferenceisoften

Inhomogeneous,andthisresultisthesameastheeffectofnonuniformityoftheeffectiveradius

The.Inanarrowsense,heterogeneityistheinhomogeneityoftheverticalspringrate.

Three,tireandsteelringweightofUNBALANCE

Ineccentricstate,eveniftheweightofTIREandWHEELisBALANCE,

Atthemomentofrotation,thereisstillcentrifugalforceactingontheaxleandmovingathighspeed

Figuretwo

3/20

Theforceisevenmorestriking.Themagnitudeoftheforceisasfollows:

E（2,f）2

G

W

F=P

F:

centrifugalrate（KGF）

W:

TIREandWHEELgrossweight（KGF）

G:

theaccelerationofgravity（980cm.Sec-2）

E:

eccentricity（CM）

revolutionspersecond（Hz）

ThisisappliedtotheforcesonTIRE,andthereactionisshownintheprevioussection2

TheshapemakespoorcomfortevenifthereisnoeccentricityduetoTIREandWHEEL

TheUNBALANCEatallpointsofthecircumferencewillalsoproducethecentrifugalforceasmentionedabove.to

HighspeedtravelshouldpayspecialattentiontotheTIREandWHEELofBALANCE

UsuallytoleadtoweightTIREandWHEELtokeeptheBALANCE.

Four.Uniformityoftire

TIREismadeofdifferentlayersofrubber,rayonandsteelwire,asregards

Size,rigidity,weight,etccollectivelyUNBALANCE,suchasTIREfullcircle

ThechangeintheradiusofeachpointiscalledtheTIREofRUNOUT.Infact,TIREisalso

Thestateofnoncircularity,thatis,irregularshapes,suchaspolygons,whichcauses

TIREvibrateswhenitrotates.

AsshowninFigure3,theTIREcanbeconsideredasacentralizedverticalspring.RUNOUTsizeisnot

Beincludedin,if

TheverticalspringrateofeachpointoftheTIREroundisnotthesame

TIRE

Sufferfrompoorcomfortcausedbyforcedvibration.

to

Ourknowledgeof80~130

Atthespeedofthe/hr,excludetheabove

Ofthe3item

UNBALANCE

and

TheoccurrenceofNON-UNIFORMITYislowfrequencyvibration,andtheshockwillbesmaller

（Yulun

Tirespeed

10~20Hz）.

chart

4isnothomogeneous

TIREcomplexwaveform,theanalysisofthewaveformisdivided

by

TIRErotatesonceandfluctuatesoverandoveragain

Simpleharmonic

）twoorthreetimes

.......

Thetentime,inthiscase

TIREYu

60rpmrotatesatlowspeedandathighspeed

Thereisaslightlydifferentwaveformbetweenthecentrifugalforceandtheweightduetoseparation.inshort

Once,Jane

Theharmonicisrelatedtothewobble,

Thetwooneisrelatedtonoise,shockorunevenrunninginthecar,

Theseareimportantfactors.

4/20

5/20

1,SHAKE

Occurringinthevibrationofarevolution,asanaudiblenoise,andateveryturn

RotationoccurssimilartotheexcitationofUNBALANCE,whichiscausedbyTIREonce

Thefrequencyofharmonicis11~17Hz.

2,THUMP

Theimpactoccurredonceeveryturn,occasionallyaccompaniedbyshocks.Feel

IfthereisasmallFLAT-SPOT,thisisbecauseTIREfourthtimes~13timestheharmonic,

Itsfrequencyis30~60Hz.

3,ROUGHNESS

Similartolowfrequencyrumble,chassis,steeringwheelvibrationandnoiseofthedrivesystem

ThisoccursbecauseofthefourtothirteenharmonicofTIRE,thefrequencyrange

30~130Hz.

6/20

DeterminationitemsanddefinitionsofU/Fmeasuringmachines

I.projectofhomogeneity

（A）RADIAL,FORCE,VARIATION（RFV）

（B）LATERAL,FORCE,VARIATION（LFV）

（C）TRACTIVE,FORCE,VARIATION（TFV）

（D）LATERAL,FORCE,DEVIATION（LFD）

（E）CONICITY

（F）PLYSTEER

（G）RADIALRUNOUT（RRO）

（H）LATERALRUNOUT（LRO）

（I）FIRSTHARMONIC（1s,t,HAR）

（J）HIGHPOINT

（K）PEAKPOINT

Two.Determinationofthedefinitionofindividualprojects

（A）theforcechangevalue（KGF）ofRFV:

TIREinradiation（vertical）direction.

（B）LFV:

TIREchangesinlateralforces（KGF）.

（C）TFV:

TIREchangesinfrontandbackdirectionsofgravity（KGF）.

（D）theintegralmeanofLFD:

TIREintransverseforce（KGF）.

（E）CONICITY:

theintegralaverageofthetransverseforce,evenifthedirectionofrotationchanges

Donotchangeitsdirection（KGF）.

（F）PLYSTEER:

theintegralofthetransverseforce,themean,thedirectionofrotationchanges,thesquareofit

Andthenchange

（KGF）.

（G）RRO:

DeformationinthedirectionofTIRERADIAL

（mm）.

（H）LRO:

TransversedeformationoftheTIREtread

（I）1stHAR:

constitute

RFVor

LFVonesubharmonicchange

（J）HIGHPOINT:

onepointtoshowthehighestvalueofasimpleharmonic

（General

Pointtopoint

）.

（K）PEAKPOINT:

alittletoshow

RFVand

HighestvalueofLFV

（a

Atanangle

7/20

8/20

Three,individualprojects

1,RFV（RADIAL,FORCE,VARIATION）（Ref.Fig.2）

TheTIREappliestheproperloadanditsrotationcenterisconstantwiththeLOADWHEEL

ThecenterkeepsacertaindistancefromwhichtheRADIALdirectionforcevarieswiththeRFVtable

Show.GenerallyproducewaveformsasshowninFigure2,thewaveformofthehighestpointtothelowestpoint

ThedifferenceiscalledRFV.

2,LFV（LATERAL,FORCE,VARIATION）（Ref.Fig.3）

TheTIREappliestheproperloadanditscenterofrotationisinLOADWHEEL

ThechangeinthelateralforcesproducedbytheheartatadistanceisexpressedinLFV.One

Thewaveform,asshowninFig.3,iscalledthedifferencebetweenthehighestandlowestpointsofthewaveform

It'

sLFV.

9/20

3,TFV（TRACTIVE,FORCE,VARIATION）（Ref.Fig.4）

ThedistancebetweenthefrontandbackoftheheartischangedbyTFV,

Generally,thewaveformofthewaveformshowninFig.4isthedifferencebetweenthehighestandlowestpointsofthewaveform

CallitTFV.

4,LFD（LATERAL,FORCE,DEVIATION）（Ref.Fig.5）

Fromthe0kgfcalculation,theintegralmeanvalueofthetransverseforceisexpressedasLFD.

10/20

5,CONICITY

Transverseforceintegralmean,evenifthedirectionofrotationoftheTIREchangesitsforcedirection

Thesamedoesnotmean"

CONICITY"

.ItsvaluecanbeexpressedbyLFDinthefollowingformula,

LFD1byclockwiserotation,LFD2byanticlockwiserotation:

Two

LFD1LFD2

CONICITY

+

=

CONICITYisillustratedbyexample,suchasTIRE,whoseexternalshapeisobliquelytapered,asinExample

AsshowninFigure7,theforwardorbackwardrotationoftheTIREwillnecessarilymakeitleantotheleft.this

ThatiswhyCONICITYisalsoknownas"

PSEUDO-CAMBER"

Causes.

6,PLYSTEER

TheoccurrenceofPLYSTEERconstitutestheBELTattachmentangleoftheTIREperiphery

ThevariationofthetransverseforceproducedbythisforceissimilartothatoftheSLIPangleofthegeneralTIRE

11/20

Similarly,thevaluesofPLYSTEERcanbesimilartothoseofLFDlandLFD2inthefollowingexpressions.

PLYSTEER

-

7,RRO（RADIAL,RUNOUT）（Ref.Fig.8,and,Fig.9）

ThechangeinRROisthatthefetalfaceismeasuredbythewheelwhenTIREisat60rpm

Measuredbythedifferencebetweenthehighestandlowestpointsofthewaveform,thevalueisRRO.

*thegeneralinstrumentisplacedatthecenterofthetreadofthetwosidesofthetireshoulder,atotalof3points,takethemost

Bigvalue.

*non-contactmeasuringsystemsdonotusemeasuringwheels.Thisappliesto

T/B'

sU/Fmachines.

8,LRO（LATERAL,RUNOUT）

ThechangeinLROisthepotentiometeronthesecondsideoftheTIREmeasuredbythewheelof60rpm

Measuredbythedifferencebetweenthehighestandlowestpointsofthewaveform,thevalueisLRO.

Generally,thehorizontalpositionaboveTIREisthepointofmeasurement,buttheLABtype

ItmaybethepointaboveorbelowTIREasthepointofmeasurement.

12/20

Thenon-contactmeasuringsystemdoesnotusemeasuringwheels,whichisapplicabletoT/B

U/Fmachinery.

9,1st,HAR（FIRST,HARHONIC）（Ref.Fig.10）

RepresentsachangeinthevalueofoneharmonicofaRFVorLFV（sinewave）.

ReferringtoFig.10isthetotalwaveform,consistingofasimpleharmonicandisincludedinthetotalwaveform,

Asshowninthevir