外文翻译悬架系统的基本元件文档格式.docx

外文翻译悬架系统的基本元件文档格式.docx

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ssuspensionsystemisautomotiveengineeringatitsbest.

Thecomponentsofthesuspensionsystemperformsixbasicfunctions:

1.Maintaincorrectvehiclerideheight

2.Reducetheeffectofshockforces

3.Maintaincorrectwheelalignment

4.Supportvehicleweight

5.Keepthetiresincontactwiththeroad

6.Controlthevehicle’sdirectionoftravel

However,inorderforthistohappen,allthesuspensioncomponents,bothfrontandrear,mustbeingoodworkingcondition.

MAINCOMPONENTSOFAMODERNSUSPENSIONSYSTEM

Atthispoint,it'

simportanttounderstandthatthemaincomponentsofamovingvehiclesuspensionsystemaretheStruts,ShockAbsorbers,SpringsandTires.Wewillfirstturnourattentiontothedesignandfunctionofsprings.Inthefollowingsectionwewillthoroughlyexaminethefunctionanddesignofshockabsorbersandstrutassemblies.

Thespringssupporttheweightofthevehicle,maintainrideheight,andabsorbroadshock..Springsaretheflexiblelinksthatallowtheframeandthebodytoriderelativelyundisturbedwhilethetiresandsuspensionfollowthebumpsintheroad.

Springsarethecompressiblelinkbetweentheframeandthebody.Whenanadditionalloadisplacedonthespringsorthevehiclemeetsabumpintheroad,thespringswillabsorbtheloadbycompressing.Thespringsareaveryimportantcomponentofthesuspensionsystemthatprovidesridecomfort.Shocksandstrutshelpcontrolhowfastthespringsandsuspensionareallowedtomove,whichisimportantinkeepingtiresinfirmcontactwiththeroad.

Duringthestudyofsprings,thetermbouncereferstothevertical（upanddown）movementofthesuspensionsystem.Theupwardsuspensiontravelthatcompressesthespringandshockabsorberiscalledthejounce,orcompression.Thedownwardtravelofthetireandwheelthatextendsthespringandshockabsorberiscalledrebound,orextension.

Whenthespringisdeflected,itstoresenergy.Withoutshocksandstrutsthespringwillextendandreleasethisenergyatanuncontrolledrate.Thespring'

sinertiacausesittobounceandoverextenditself.Thenitre-compresses,butwillagaintraveltoofar.Thespringcontinuestobounceatitsnaturalfrequencyuntilalloftheenergyoriginallyputintothespringisused.

Ifthestrutsorshockabsorbersarewornandthevehiclemeetsabumpintheroad,thevehiclewillbounceatthefrequencyofthesuspensionuntiltheenergyofthebumpisusedup.Thismayallowthetirestolosecontactwiththeroad.

Strutsandshockabsorbersthatareingoodconditionwillallowthesuspensiontooscillatethroughoneortwodiminishingcycles,limitingordampingexcessivemovement,andmaintainingverticalloadsplaceduponthetires.Thishelpskeepthetiresincontactwiththeroad.

Bycontrollingspringandsuspensionmovement,componentssuchastierodswilloperatewithintheirdesignrangeand,whilethevehicleisinmotion,dynamicwheelalignmentwillbemaintained.

SPRINGDESIGNS

Beforediscussingspringdesign,itisimportanttounderstandsprungandunsprungweight.Sprungweightistheweightsupportedbythesprings.Forexample,thevehicle'

sbody,transmission,frame,andmotorwouldbesprungweight.Unsprungweightistheweightthatisnotcarriedbysprings,suchasthetires,wheels,andbrakeassemblies.

Thespringsallowtheframeandvehicletorideundisturbedwhilethesuspensionandtiresfollowtheroadsurface.Reducingunsprungweightwillprovidelessroadshock.Ahighsprungweightalongwithalowunsprungweightprovidesimprovedrideandalsoimprovedtiretraction.

Therearefourmajorspringdesignsinusetoday:

coil,leaf,torsionbar,andair.

CoilSprings

Themostcommonlyusedspringisthecoilspring.Thecoilspringisalengthofroundspringsteelrodthatiswoundintoacoil.Unlikeleafsprings,conventionalcoilspringsdonotdevelopinter-leaffriction.Therefore,theyprovideasmootherride.

Thediameterandlengthofthewiredeterminethestrengthofaspring.Increasingthewirediameterwillproduceastrongerspring,whileincreasingitslengthwillmakeitmoreflexible.

Springrate,sometimesreferredtoasdeflectionrate,isusedtomeasurespringstrength.Itistheamountofweightthatisrequiredtocompressthespring1inch.Forexample:

Ifittakes100lbs.tocompressaspring1inch,itwouldtaketo200lbs.tocompressthespring2inches.

Somecoilspringsaremadewithavariablerate.Thisvariablerateisaccomplishedbyeitherconstructingthisspringfrommaterialshavingdifferentthicknessorbywindingthespringsothecoilwillprogressivelycompressatahigherrate.Variableratespringsprovidealowerspringrateunderunloadedconditionsofferingasmootherride,andahigherspringrateunderloadedconditions,resultinginmoresupportandcontrol.

Coilspringsrequirenoadjustmentandforthemostpartaretrouble-free.Themostcommonfailureisspringsag.Springsthathavesaggedbelowvehicledesignheightwillchangethealignmentgeometry.Thiscancreatetirewear,handlingproblems,andwearothersuspensioncomponents.Duringsuspensionserviceitisveryimportantthatvehiclerideheightbemeasured.Rideheightmeasurementsnotwithinmanufacturer’sspecificationsrequirereplacementofsprings.

LeafSprings

Leafspringsaredesignedtwoways:

multi-leafandmono-leaf.Themulti-leafspringismadeofseveralsteelplatesofdifferentlengthsstackedtogether.Duringnormaloperation,thespringcompressestoabsorbroadshock.Theleafspringsbendandslideoneachotherallowingsuspensionmovement.

Anexampleofamono-leafspringisthetaperedleafspring.Theleafisthickinthemiddleandtaperstowardthetwoends.Manyoftheseleafspringsaremadeofacompositematerial,whileothersaremadeofsteel.

Inmostcasesleafspringsareusedinpairsmountedlongitudinally（fronttoback）.However,thereareanincreasingnumberofvehiclemanufacturersusingasingletransverse（sidetoside）mountedleafspring.

TorsionBar

Anothertypeofspringisthetorsionbar.ThetorsionbarisastraightorLshapedbarofspringsteel.Mosttorsionbarsarelongitudinal,mountedsolidlytotheframeatoneendandconnectedtoamovingpartofthesuspensionattheother.Torsionbarsmayalsobetransversemounted.Duringsuspensionmovement,thetorsionbarwilltwist,providingspringaction.

AirSprings

Theairspringisanothertypeofspringthatisbecomingmorepopularonpassengercars,lighttrucks,andheavytrucks.Theairspringisarubbercylinderfilledwithcompressedair.Apistonattachedtothelowercontrolarmmovesupanddownwiththelowercontrolarm.Thiscausesthecompressedairtoprovidespringaction.Ifthevehicleloadchanges,avalveatthetopoftheairbagopenstoaddorreleaseairfromtheairspring.Anonboardcompressorsuppliesair.

TiresasSprings

Anoften-overlookedspringisthetire.Tiresareairspringsthatsupportthetotalweightofthevehicle.Theairspringactionofthetireisveryimportanttotheridequalityandsafehandlingofthevehicle.Asamatteroffact,tiresmaybeviewedasthenumber-oneridecontrolcomponent.Tiresize,construction,compoundandinflationareveryimportanttotheridequalityofthevehicle.

STRUTMOUNTDESIGN

Strutmountsarevehiclespecific,andtherearenumerousdesignsinusetodayonbothfrontandrearsuspensionsystems.Thethreemostcommondesignsareinnerplate,centersleeve,andspacerbushing.

TheInnerPlateDesignusedbyGeneralMotorsandsomeFordapplicationsfeatureaninnerplateencasedinmoldedrubbersurroundedbyupperandlowersurfaceplates.Theinnerplateisdesignedsothestrutpistonrodcannotpushthroughtheupperorlowersurfaceplateiftherubbercorefails.Thisdesigngenerallydoesnotrequirewashers.Duetothefactthattheupperandlowerserviceplatesmostlycovertherubberportionofthemount,itisdifficulttoseeiftheinnerrubberbushinghasfailed.However,thesecomponentswearovertimeandwithathoroughinspectionaproperrecommendationcanbemade.Thebearingislocatedonthebottomofthestrutmountandisnotserviceable.Defectivebearingwillrequirereplacementoftheentirestrutmount.

TheCenterSleeveDesignusedbyChryslerfeaturesacentersleevethatismoldedtotherubberbushing.Thisdesignprovidesincreasedsidetosidestability.Thestrutstemextendsthroughthecentersleeve.Upperandlowerretainerwasherspreventthestrutrodfrompushingthroughthestrutmount.Thebearingisaseparatecomponentfromthestrutmount.Ifinspectionrevealscracksortearsintherubberbushing,replacementisrequired.Ifthebearingisfoundtobedefectiveitcanbereplacedseparately.

TheSpacerBushingDesignusedbyVolkswagen,Toyota,Mazda,Mitsubishi,andearlyChryslervehiclesfeaturecenterpositioningofthebearingandaseparateinnerbushinginsteadofamoldedinnersleeve.Theoperationissimilartothestylewejustdiscussedexceptthebearingispressedinthestrutmount.Thebearings,washer,andtheupperplateretainthestrutrod.Iftherubberbushingiscracked,torn,orthebearingisbindingorseized,thestrutmountrequiresreplacement.

ANTI-SWAYBARS

Anotherimportantcomponentofasuspensionsystemistheanti-swaybar.Thisdeviceisusedalongwithshockabsorberstoprovideadditiona