汽车悬架工作原理全英文32177.docx

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1、How Car Suspensions WorkTable of Contents: Introduction to How Car Suspensions Work VVehiiclee Dyynammicss TThe Chaassiis SSpriingss SSpriingss: SSpruung andd Unnsprrungg Maass DDampperss: SShocck AAbsoorbeers DDampperss: SStruuts andd Annti-swaay BBarss SSusppenssionn Tyypess: FFronnt SSusppenssion

2、n Tyypess: RRearr SSpecciallizeed SSusppenssionns: Thee Baaja Bugg SSpecciallizeed SSusppenssionns: Forrmulla OOne Raccerss SSpecciallizeed SSusppenssionns: Hott Roods TThe Futturee off Caar SSusppenssionns LLotss Moore Infformmatiion CCompparee Prricees ffor Carr SuuspeensiionssWhen peooplee thhink

3、k off auutommobiile perrforrmannce, thhey norrmallly thiink of horrseppoweer, torrquee annd zzeroo-too-600 acccelleraatioon. Butt alll oof tthe powwer genneraatedd byy a pisstonn ennginne iis uusellesss iff thhe ddrivver cannt conntrool tthe carr. TThatts whyy auutommobiile enggineeerss tuurneed tth

4、eiir aatteentiion to thee suuspeensiion sysstemm allmosst aas ssoonn ass thhey hadd maasteeredd thhe ffourr-sttrokke iinteernaal ccombbusttionn ennginne. Photoo coourttesyy Hoondaa Mootorr Coo., Ltdd.Dooublle-wwishhbonne ssusppenssionn onn Hoondaa Acccorrd 220055 CooupeeThe jjob of a ccar susspennsi

5、oon iis tto mmaxiimizze tthe friictiion bettweeen tthe tirres andd thhe rroadd suurfaace, too prroviide steeeriing staabillityy wiith goood hhanddlinng aand to enssuree thhe ccomffortt off thhe ppasssenggerss. IIn tthiss arrticcle, weelll exxploore howw caar ssusppenssionns wworkk, hhow theeyvve eev

6、ollvedd ovver thee yeearss annd wwherre tthe dessignn off suuspeensiionss iss heeadeed iin tthe futturee. Vehiccle Dynnamiics（汽汽车动力力学）IIf aa rooad werre pperffecttly flaat, witth nno iirreegullariitiees, susspennsioons wouuldnnt be neccesssaryy. BBut roaads aree faar ffromm fllat. Evven freeshlly pp

7、aveed hhighhwayys hhavee suubtlle iimpeerfeectiionss thhat cann innterractt wiith thee whheells oof aa caar. Its tthesse iimpeerfeectiionss thhat appply forrcess too thhe wwheeels. Acccorrdinng tto NNewttons llawss off mootioon（牛牛顿运动动理论）, all forces have both magnitude（大小） and direction. A bump（撞击）i

8、n the road causes the wheel to move up and down perpendicular（垂直的） to the road surface. The magnitude, of course, depends on whether the wheel is striking a giant bump or a tiny speck（斑点）. Either way, the car wheel experiences a vertical acceleration as it passes over an imperfection. Withoout an in

9、ttervveniing（介介入） strructturee, aall of wheeels vvertticaal eenerrgy is traansfferrred to thee frramee, wwhicch mmovees iin tthe samme ddireectiion. Inn suuch a ssituuatiion, thhe wwheeels cann loose conntacct wwithh thhe rroadd coomplleteely. Thhen, unnderr thhe ddownnwarrd fforcce oof ggravvityy,

10、tthe wheeelss caan sslamm baack intto tthe roaad ssurffacee. WWhatt yoou nneedd iss a sysstemm thhat willl aabsoorb thee ennerggy oof tthe verrticcallly aacceelerrateed wwheeel, alllowiing thee frramee annd bbodyy too riide unddistturbbed whiile thee whheells ffolllow bummps in thee rooad. The sstud

11、dy oof tthe forrcess att woork on a mmoviing carr iss caalleed vvehiiclee dyynammicss, aand youu neeed to unddersstannd ssomee off thhesee coonceeptss inn orrderr too apppreeciaate whyy a susspennsioon iis nneceessaary in thee fiirstt pllacee. MMostt auutommobiile enggineeerss coonsiiderr thhe ddyna

12、amiccs oof aa moovinng ccar froom ttwo perrspeectiivess: Ride - aa caarss abbiliity to smooothh ouut aa buumpyy rooad Handllingg - a ccars aabillityy too saafelly aacceelerratee, bbrakke aand corrnerr Thesee twwo ccharractteriistiics cann bee fuurthher desscriibedd inn thhreee immporrtannt pprinncip

13、pless - roaad iisollatiion, rooad holldinng aand corrnerringg. TThe tabble bellow desscriibess thhesee prrincciplles andd hoow eengiineeers atttemppt tto ssolvve tthe chaalleengees uuniqque to eacch. PrincciplleDefinnitiionGoalSoluttionnRoad IsoolattionnThe vvehiiclees abiilitty tto aabsoorb or isoo

14、latte rroadd shhockk frrom thee paasseengeer ccompparttmenntAlloww thhe vvehiiclee boody to ridde uundiistuurbeed wwhille ttravveliing oveer rrouggh rroadds.Absorrb eenerrgy froom rroadd buumpss annd ddisssipaate（驱驱散） it witthouut ccaussingg unnduee（不恰恰当的） oscillation（振动） in the vehicle.Road Holldin

15、ngThe ddegrree to whiich a ccar maiintaainss coontaact witth tthe roaad ssurffacee inn vaarioous typpes of dirrecttionnal chaangees aand in a sstraaighht llinee (EExammplee: TThe weiightt off a carr wiill shiift froom tthe reaar ttirees tto tthe froont tirres durringg brrakiing. Beecauuse thee noose

16、 of thee caar ddipss toowarrd tthe roaad, thiis ttypee off mootioon iis kknowwn aas divve. Thhe ooppoositte eeffeect - sqquatt - ooccuurs durringg acccelleraatioon, whiich shiiftss thhe wweigght of thee caar ffromm thhe ffronnt ttirees tto tthe bacck.)Keep thee tiiress inn coontaact witth tthe groou

17、ndd, bbecaausee itt iss thhe ffricctioon bbetwweenn thhe ttirees aand thee rooad thaat aaffeectss a vehhiclless abbiliity to steeer, brrakee annd aacceelerratee.Minimmizee thhe ttrannsfeer oof vvehiiclee weeighht ffromm siide to sidde aand froont to bacck, as thiis ttrannsfeer oof wweigght redducees

18、 tthe tirress grrip on thee rooad.CorneerinngThe aabillityy off a vehhiclle tto ttravvel a ccurvved patthMinimmizee boody rolll, whiich occcurss ass ceentrrifuugall foorcee puushees ooutwwardd onn a carrs cennterr off grraviity whiile corrnerringg, rraissingg onne ssidee off thhe vvehiiclee annd llo

19、weerinng tthe oppposiite sidde.Transsferr thhe wweigght of thee caar dduriing corrnerringg frrom thee hiigh sidde oof tthe vehhiclle tto tthe loww siide.A carrs susspennsioon, witth iits varriouus ccompponeentss, pprovvidees aall of thee sooluttionns ddesccribbed. Letss loook at thee paartss off a t

20、yppicaal ssusppenssionn, wworkkingg frrom thee biiggeer ppictturee off thhe cchasssiss doown to thee inndivviduual commponnentts tthatt maake up thee suuspeensiion prooperr. The CChasssissThee suuspeensiion of a ccar is acttuallly parrt oof tthe chaassiis, whiich commpriisess alll oof tthe impportta

21、ntt syysteems loccateed bbeneeathh thhe ccars bbodyy. ChasssisThesee syysteems inccludde: The fframme - sttruccturral, looad-carrryiing commponnentt thhat suppporrts thee caarss ennginne aand boddy, whiich aree inn tuurn suppporrtedd byy thhe ssusppenssionn The ssusppenssionn syysteem - seetupp thha

22、t suppporrts weiightt, aabsoorbss annd ddamppenss shhockk annd hhelpps mmainntaiin ttiree coontaact The ssteeerinng ssysttem - mmechhaniism thaat eenabbless thhe ddrivver to guiide andd diirecct tthe vehhiclle The ttirees aand wheeelss - commponnentts tthatt maake vehhiclle mmotiion posssibble by wa

23、yy off grrip andd/orr frricttionn wiith thee rooad So thhe ssusppenssionn iss juust onee off thhe mmajoor ssysttemss inn anny vvehiiclee. With thiis bbig-piccturre ooverrvieew iin mmindd, iitss tiime to loook aat tthe thrree funndammenttal commponnentts oof aany susspennsioon: sprringgs, dammperrs a

24、and antti-sswayy baars. SprinngsTTodaayss spprinnginng ssysttemss arre bbaseed oon oone of fouur bbasiic ddesiignss: Coil sprringgs - Thhis is thee moost commmonn tyype of sprringg annd iis, in esssencce, a hheavvy-ddutyy toorsiion barr cooileed aarouund an axiis. Coiil sspriingss coomprresss annd e

25、expaand to abssorbb thhe mmotiion of thee whheells. Photoo coourttesyy Caar DDomaainCCoill spprinngsPhotoo coourttesyy HoowSttufffWorrks ShooppeerLeeaf sprringg Leaf sprringgs - Thhis typpe oof sspriing connsissts of sevveraal llayeers of mettal (caalleed leaavess) bouund toggethher to actt ass a si

26、nnglee unnit. Leeaf sprringgs wweree fiirstt ussed on horrse-draawn carrriaagess annd wweree fooundd onn moost Ameericcan auttomoobilles unttil 19885. Theey aare stiill useed ttodaay oon mmostt trruckks aand heaavy-dutty vvehiiclees. Torsiion barrs - Toorsiion barrs（扭扭力杆） use the twisting properties

27、 of a steel bar to provide coil-spring-like performance. This is how they work: One end of a bar is anchored to the vehicle frame. The other end is attached to a wishbone, which acts like a lever that moves perpendicular to the torsion bar. When the wheel hits a bump, vertical motion is transferred

28、to the wishbone and then, through the levering action, to the torsion bar. The torsion bar then twists along its axis to provide the spring force. European carmakers used this system extensively, as did Packard and Chrysler in the United States, through the 1950s and 1960s. Photoo coourttesyy HoowSt

29、tufffWorrks ShooppeerToorsiion barr Air sspriingss - Airr spprinngs, whhichh coonsiist of a ccyliindrricaal cchammberr off aiir pposiitioonedd beetweeen thee whheell annd tthe carrs boddy, usee thhe ccomppresssivve qquallitiies of airr too abbsorrb wwheeel vvibrratiionss. TThe connceppt iis aactuual

30、lly mmoree thhan a ccentturyy olld aand couuld be fouund on horrse-draawn bugggiees. Airr spprinngs froom tthiss erra wweree maade froom aair-fillledd, lleattherr diiaphhraggms, muuch likke aa beelloows; thhey werre rrepllaceed wwithh mooldeed-rrubbber（橡橡胶浇筑筑） aair sprringgs iin tthe 19330s. Photoo

31、coourttesyy HSSW SShoppperrAirr spprinngsBasedd onn whheree spprinngs aree loocatted on a ccar - i.ee., bettweeen tthe wheeelss annd tthe fraame - enggineeerss offtenn fiind it connvenniennt tto ttalkk abboutt thhe sspruung masss aand thee unnsprrungg maass. Sprinngs: Spprunng aand Unsspruung Masss（

32、簧簧下质量量）Thhe sspruung masss iis tthe masss oof tthe vehhiclle ssuppportted on thee spprinngs, whhilee thhe uunspprunng mmasss iss loooseely deffineed aas tthe masss bbetwweenn thhe rroadd annd tthe susspennsioon sspriingss. TThe stiiffnnesss off thhe sspriingss afffeccts howw thhe sspruung masss rres

33、ppondds wwhille tthe carr iss beeingg drriveen. Loooselly sspruung carrs, succh aas lluxuury carrs (thiink Linncolln TTownn Caar), caan sswallloww buumpss annd pprovvidee a supper-smooothh riide; hoowevver, suuch a ccar is proone to divve aand squuat durringg brrakiing andd acccelleraatioon aand ten

34、nds to expperiiencce bbodyy swway or rolll dduriing corrnerringg. TTighhtlyy spprunng ccarss, ssuchh ass spportts ccarss (tthinnk MMazdda MMiatta), arre llesss foorgiivinng oon bbumppy rroadds, butt thhey minnimiize boddy mmotiion welll, whiich meaans theey ccan be driivenn agggreessiivelly, eveen a

35、arouund corrnerrs. So, wwhille sspriingss byy thhemsselvves seeem llikee siimplle ddeviicess, ddesiigniing andd immpleemenntinng tthemm onn a carr too baalannce passsenngerr coomfoort witth hhanddlinng iis aa coompllex tassk. Andd too maake mattterrs mmoree coompllex, spprinngs aloone cannt proovidd

36、e aa peerfeectlly ssmoooth ridde. Whyy? BBecaausee spprinngs aree grreatt att abbsorrbinng eenerrgy, buut nnot so goood aat ddisssipaatinng iit. Othher strructturees, knoown as dammperrs, aree reequiiredd too doo thhis. Histooriccal SusspennsioonsSixteeentth-ccentturyy waagonns aand carrriaagess trr

37、iedd too soolvee thhe pprobblemm off ffeellingg evveryy buump in thee rooad byy sllinggingg thhe ccarrriagge bbodyy frrom leaatheer sstraaps atttachhed to fouur ppostts oof aa chhasssis thaat llookked likke aan uuptuurneed ttablle. Beccausse tthe carrriaage boddy wwas susspenndedd frrom thee chhasss

38、is, thhe ssysttem camme tto bbe kknowwn aas aa ssusppenssionn - aa teerm stiill useed ttodaay tto ddesccribbe tthe enttiree cllasss off sooluttionns. Thee sllungg-boody susspennsioon wwas nott a truue sspriingiing sysstemm, bbut it didd ennablle tthe boddy aand thee whheells oof tthe carrriaage to m

39、ovve iindeepenndenntlyy. Semi-ellliptticaal sspriing dessignns, alsso kknowwn aas ccartt spprinngs, quuickkly repplacced thee leeathher-strrap susspennsioon. Poppulaar oon wwagoons, buuggiies andd caarriiagees, thee seemi-ellliptticaal sspriingss weere oftten useed oon bbothh thhe ffronnt aand reaar

40、 aaxlees. Theey ddid, hoowevver, teend to alllow forrwarrd aand bacckwaard swaay aand hadd a higgh ccentter of graavitty. By thhe ttimee poowerred vehhiclles hitt thhe rroadd, ootheer, morre eeffiicieent sprringgingg syysteems werre bbeinng ddeveelopped to smooothh ouut rridees ffor passsenngerrs.Da

41、mpeers: Shhockk AbbsorrberrsUnnlesss aa daampeeninng sstruuctuure is preesennt, a ccar sprringg wiill exttendd annd rreleeasee thhe eenerrgy it abssorbbs ffromm a bummp aat aan uuncoontrrollled ratte. Thee spprinng wwilll coontiinuee too boouncce（反反弹） at itss naaturral freequeencyy unntill alll oof

42、tthe eneergyy orrigiinallly putt innto it is useed uup. A ssusppenssionn buuiltt onn spprinngs aloone wouuld makke ffor an exttremmelyy boounccy rridee annd, deppenddingg onn thhe tterrrainn, aan uuncoontrrolllablle ccar. Enterr thhe sshocck aabsoorbeer, or snuubbeer（缓缓冲器）, a device that controls un

43、wanted spring motion through a process known as dampening. Shock absorbers slow down and reduce the magnitude of vibratory motions by turning the kinetic energy （动能）of suspension movement into heat energy that can be dissipated through hydraulic fluid. To understand how this works, its best to look

44、inside a shock absorber to see its structure and function. A shoock abssorbber is bassicaallyy ann oiil ppumpp pllaceed bbetwweenn thhe fframme oof tthe carr annd tthe wheeelss. TThe uppper mouunt of thee shhockk coonneectss too thhe fframme (i.ee., thee spprunng wweigght), wwhille tthe lowwer mouun

45、t connneccts to thee axxle, neear thee whheell (ii.e., tthe unsspruung weiightt). In a ttwinn-tuube dessignn, oone of thee moost commmonn tyypess off shhockk abbsorrberrs, thee uppperr moountt iss coonneecteed tto aa piistoon rrod, whhichh inn tuurn is connnecctedd too a pisstonn, wwhicch iin tturnn

46、 siits in a ttubee fiilleed wwithh hyydraauliic ffluiid. Thee innnerr tuube is knoown as thee prresssuree tuube, annd tthe outter tubbe iis kknowwn aas tthe resservve ttubee. TThe resservve ttubee sttorees eexceess hyddrauulicc flluidd. When thee caar wwheeel eencoountterss a bummp iin tthe roaad aand cauusess thhe sspriing to coiil aand unccoill, tthe eneergyy off thhe sspriing is traansfferrred to thee shhockk abbsorrberr thhrouugh thee uppperr moountt, ddownn thhrouugh thee piistoon rrod andd innto thee piistoon. Oriificces perrforratee