轮胎不规则磨耗机理-测试-改良

Confidential,轮胎不规则磨耗机理/测试/改良,欧阳博二九年五月廿五日,Confidential,内容提纲,简介1983北美All-SeasonPCR轮胎之不规则磨耗问题不规则磨耗机理之分析如何应对和改进不规则磨耗问题试验室高效测试法之思考,Confidential,简介不规则磨耗之种类不规则磨耗之可能原因,Confidential,不规则磨耗之种类,AlternateLugWearBothShoulderWearBrakeSkid/FlatSpotWear,SpottyWearCupping/ScallopWearDiagonalWear,Confidential,不规则磨耗之种类,Erosion/River/ChannelWearFeatherEdgeWear,ShoulderStep/ChamferWearOne-SidedWear,Confidential,不规则磨耗之种类,RibPunchWearShoulderScrubbing/ScuffingWear,Heel&ToeWear,Confidential,不规则磨耗之可能原因,悬挂系统问题设计维护轮胎使用与维护充气压不当不当使用刹车，转弯过猛超载胎压不足,Confidential,不规则磨耗之可能原因,轮胎设计和制造质量问题胎面花纹设计花纹块弱/不稳定胎面胶不耐磨，过软胎体胎冠设计胎体或带束刚性不足轮胎制造质量均匀性不良,Confidential,1983北美All-SeasonPCR轮胎之不规则磨耗问题非驱动轮胎(undriventires)二/四行花纹严重Heel&ToeWearAll-Season胎用块状花纹多为高速公路之磨耗，条件相对温和,Confidential,1983Uniroyal调查结果,Confidential,Ludwig,G.S.andBrenner,F.C.,DistributionofSpeedandAccelerationonaTreadwearCourse,TireScienceandTechnology,v.9,Nos,1-4,1981,典型子午胎耐磨性路試時，橫向及縱向加速度分佈圖,橫向,縱向,Confidential,进一步观察驱动轮胎:OSS胎面有ShoulderWear其余磨耗轻微，且均匀非驱动轮胎:OSS胎面有ShoulderWear二/四行花纹严重Heel&ToeWear,Confidential,前轮驱动后轮驱动前轮后轮前轮后轮磨耗率快较慢快较慢磨耗均匀不均匀不均匀均匀驱动制动转弯自由滚动,高速公路轮胎不规则磨耗分析,Confidential,此类不规则磨耗不能归之于轮胎转弯此类不规则磨耗之轮胎大部分时间处于自由滚动状态，且其他为制动与转弯，而无驱动。,高速公路轮胎不规则磨耗分析,Confidential,不规则磨耗机理之分析,Confidential,SchallamachPattern的形成是從連續打滑來的,Confidential,正常的子午胎的胎面上很難找到Schallamachpatterns,Confidential,斜交胎与子午胎耐磨性之比較,斜交子午哩程（千英哩）12+48-60+束帶無有應力大小打滑大，連續性小，間歇性Schallamachpatterns有，多無，少,Confidential,胎面膠摩耗之机理第一步：疲勞老化(Mechano-thermo-chemicaldegradation)第二步：斷裂分离卷离法(Rollformation)脫皮法(Delaminationorspalling),Confidential,Confidential,1mm,ConcreteCementandSand,Treadrubber,Treadrubber,Confidential,Confidential,RollFormationProcess,Confidential,自由滚动时Heel&ToeWear之考虑,Confidential,轮胎自由滚动之应力变化,ContactPressureSymmetric,LongitudinalShearAnti-symmetric,p-t-pshear,Confidential,制动时轮胎之应力变化,ContactPressureSkewedforward,AdditionalnegativelongitudinalShear,Resultantshear,p-t-pshear,Confidential,驱动时轮胎之应力变化,Contactpressureskewedbackward,Additionalpositivelongitudinalshear,p-t-pshear,Confidential,制动自由滚动驱动,PeaktoPeak前后剪切应力变化幅度之比较,疲劳老化速度之不同,Confidential,從刮痕看胎面打滑度与輪胎側滑角之關係（0度到1度）,Confidential,從刮痕看胎面打滑度与輪胎側滑角之關係（2度到3度）,Confidential,驱动,制动,從刮痕看胎面打滑度与輪胎驱动，制动之比较,Confidential,因此，胎面胶皮层之应变能是自由滚动时高于一般驱动状态。而块状花纹的应力-应变以及其离开地面接触时的形变，可影响其接地滑移现象，其行为概述如下:,高速公路轮胎不规则磨耗分析,Confidential,轮胎印痕比较,Proneto2/4rowirregularwear,Confidential,滚动半径(rollingradius)之定义-普通定义-点定义法,Confidential,WhatisRadius?,WebstersDictionary:Alinesegmentbetweenthecenterofacircleandanypointonitscircumference.,CircumferentialLength=Radius*2p,Confidential,Whatistherollingradiusforadeformedcircle?,ConventionalDefinition:RollingRadius=Distanceperrotation/2p,For1.000mileNRollingRadius,Confidential,滚动半径的点定义,R=DL/Dq=(XOXO)/(qBqA),Confidential,滚动半径与步跨,(XBXA)=(XD-XC)+SA+SB,Confidential,Whatcontrolthefreerollingradius?,DeflectionTreadgaugeLateralgrooveBeltlengthEdgevs.centerNyloncapInflationpressure,Confidential,如何量自由滚动半径差？,Confidential,SplitDrum,L1,L2,L3,L4,L5,L1L2L3L4L5,Confidential,SplitPlanks,Confidential,Rollingradiimismatchandrowwear,Confidential,TheTwin-TireTestMethod,Notidenticaltwin-Rollingradiimismatchabout2.5%.,Confidential,TheTwin-TireTestMethod-continued,Confidential,制動与驱動之比較：刮痕/大小輪法測試後胎面形態,Confidential,总结,All-Season轮胎块状花纹在2/4行之H/T不规则磨耗，主要是由于：非驱动轮胎胎面胶皮层之疲劳老化在自由滚动状态下，高于驱动轮胎。第2/4行花纹之自由滚动半径略小，造成较高的制动状态，不利于H&T偏磨耗。第2/4行之滚动半径之略小，与印痕形状相关，即所谓M-ness或W-ness,Confidential,总结,减少轮胎花纹行与行之间的自由滚动半径差，当有利于降低不规则磨耗。胎冠带束层及capply设计优化块状花纹，沟及sipes之设计优化小心控制双轮法中大小轮胎之自由滚动半径差，此法可能成为实验室对不规则磨耗的快速筛选试验法。,Confidential,MTS860TireIndoorWearTestMachine,Confidential,提高胎面膠耐磨性之方法,減緩胎面膠疲勞老化之速度用低滯後性膠料減少發熱以降低溫度填充料-用量，比表面積，結構，表面化學橡膠-低玻璃溫度,Tg油-品種，用量熱導率降低溫度防老劑耐老化橡膠提高膠料抗斷裂強度提高膠料之滯後性以抗斷裂填充料-用量，比表面積，結構，表面化學橡膠MW,MWD,支化度,Confidential,谢谢,Confidential,Confidential,Confidential,TireTreadwearMechanisms,TreadwearisafatiguefailureprocessDegradation:Mechano-thermo-chemicalRubberremoval:FractureRollformationofdegradedskinrubberDelamination.Wearrate(Frictionalenergy)NN=1NoslippageduringdegradationstageN1Multiplestick-slipTreadskinbrushmodel,*The“Frictionalenergy”asdefinedbyGroschshouldbecalledthetotalbulkstrainenergy.,Confidential,TireTreadwearMechanisms-conti.,Question:Inanindoorwheeltest,howwouldatirewear?Safety-walkTalcpowderTreadsurfaceconditions.nowear,oily,humpsformedwear,oily,gummy(veryslowwear,drylubricated)*wear,dryorlessoily*Justaguess,neverperformed.,Confidential,TireTreadwearMechanisms-conti.,RoadsurfacetextureAnecessity:Smooth67”wheeltestsdonotwearSkinrubberwithstressconcentrationpoints.Localslippagetakesplacewhencontactpointsexceedthestickthresholddegreeofmultiplestick-slipdependsonstresslevelsaswellastheconditionsonbothsurfaces,namely,thatofthetreadskinandtheroad.,Confidential,TireTreadwearMechanisms-conti.,RoadDustAlsoanecessityintreadwearunderdryconditions:fortherollformationprocessTheamountofdustneededisprobablynotmorethantheamountofrubberremovedToomuchdustcouldbecomedrylubricant,affectingthewearrate.,Confidential,Confidential,TreadwearPrediction,Developtreadskinbrushmode