2023年汽车制动系统机械车辆工程毕业论文英文文献及翻译

Au t omob i1e BrakeSy s tem The br a k i ng system is th e most importan t sys t emi n cars.I f t h e b r a k e s f ai1,th e resu1t can be d i sast r ous.Br a k e s are actual1y energy con v ersio n devi c es,w h i c h con v ert the kinetic ener gy m o m e n turn of t heve h icle into t h erma1energy he a t.When st e ppi ng on t h e b r ak e s,th e d r i ver comma n ds a stop p ing f o rce t e n t ime s a s p o we rf u1a s the force t h at puts th e ca r i nmotion.The brakin g system can exert t h o usands of pound s ofpress u r eon eachof th e fo u rbra kes.Tw o c o mplet e i n de p e n d en t b r ak ing sy s terns a re u s e d o n th e car.They ar e the serv i ce brake a nd the pa r k in gbra k e.T he serv i ce b ra k e ac ts t o si ow,s top,or hold th evehic1e du r i n gn ormaldriv i ng.Th ey are f oot-opera ted by th e driv e rde pre ssin gand r e le a s i ng the brak e p e d a

1.The primar y p u rpose of t he brake is to holdth ev ehicle s t at i o nary w hile i t i s u n a tt e nded.The parking br a ke ism e cha n i c a11y o perated by when a separate pa r k ing br ak e foot ped a1or ha ndlev e r is s et.T h e br ak e syst e mi s com pos edofthefollo wingbasic compo n en ts:t h e“ma s t e rc yli n d ef9which islocated un d er the hoo d,a nd i s directly connectedt o the b r ake pedal,conv er ts d r i ve r fbotsmec hani c a1p r ess u re intohyd r aul ic pres sure.Steel“bra k e li n e sand fle x i b1e“bra k e hos e s“c o nnect the mast erey lindert o th e s lave cylin d e r s1o cated at each whe e

1.Brake f1uid,s p eci ally d e s i gne d to wo rk in e x treme con ditions,fills the制动系统是由下列基本的成分组成位于发动机罩下方，并且直接地被连接到制动踏板的“制动主缸”把驾驶员脚的机械力转变为液压力钢制的“制动管路”和有柔性的“制动软管”把制动主缸连接到每个轮子的“制动轮缸”上制动液，特别地设计为的是工作在极端的情况,填充在系统中“制动盘”和“衬块”是被制动轮缸推动接触“圆盘”和“回转体”如此引起缓慢的拖拉运动，（希望）使汽车减慢速度典型的制动系统布置有前后盘式，前盘后鼓式，各个车轮上的制动器通过一套管路系统连接到制动主缸上基本上讲，所有的汽车制动器都是摩擦制动器当司机刹车时，控制装置会迫使制动蹄，或制动衬片与车轮处的旋转的制动鼓或制动盘接触接触后产生的摩擦使车轮转动减慢或停止，这就是汽车的制动在最基本的制动系统中，有一个制动主缸，这个主缸内部填充制动液，并包含两个部分,每个部分里都有一个活塞，两个活塞都连接驾驶室里的制动踏板当制动踏板被踩下时，制动液会从制动主缸流入轮缸在轮缸中,制动液推动制动蹄或制动衬片与旋转的制动鼓或制动盘接触静止的制动蹄或制动衬片与旋转的制动鼓或制动盘之间产生摩擦力使汽车的运动逐渐减缓或停止制动液的装置位于主缸的顶部目前大多数的车都有一个容易看见的装制动液的装置，为的是不用打开盖子就可以看得见制动液的油面随着制动踏板的运动制动液就会缓慢的下降，正常情况下是这样的假如制动液在很短的时间内下降得明显或者下降了三分之二，那么就要尽快的检查你的制动系统了保持制动液装置充满制动液除非你需要维修它，制动液必须保持很高的沸点位于在空气中的制动液就会吸取空气中的潮气引起制动液低丁沸点制动液通过一系列的管路从主缸到达各车轮橡胶软管只用在需要弹力的地方,比如应用在前轮在车的行进中上下来回运动系统的其它部分在所有的连接点上都应用了无腐蚀性的无缝钢管假如钢线需要修理的话，最佳的方法就是代替这条线假如这不符合实际，那么为了制动系统可以用特殊的装置修理它你不可以用铜管来修理制动系它们是危险也是不对的的鼓式制动器涉及制动鼓，一个轮缸，回拉弹簧，一个制动底版，两个带摩擦层的制动蹄制动底版固定在轮轴外部的法兰或转向节制动鼓固定在轮毂上制动鼓的内部表面与制动蹄的内层之间有空隙要使用制动器时,司机就要踩下踏板,这时轮缸扩大制动片，对其施加压力，是制动蹄触碰制动鼓制动鼓与摩擦片之间产生的摩擦制动了车轮，从而使汽车停止要释放制动器时，司机松开踏板，回拉弹簧拉回制动片，这样车轮会自由转动盘式制动器涉及制动盘而不是鼓，在它的两面上各有一个薄的制动片或叫盘式制动器的制动片制动片是靠挤住旋转的制动盘来停住汽车制动主缸里流出的制动液迫使活塞向里部的金属盘移动，这便使摩擦片紧紧地贴住制动盘这时制动片与制动盘产生的摩擦使汽车减速、停止，出现了制动行为活塞分金属或塑料盘式制动器重要有三种，即浮动卡钳型、固定卡钳型和滑动卡钳型浮动卡钳型和滑动卡钳型盘式制动器使用单活塞固定卡钳型盘式制动器既可以使用两个活塞有可以使用四个活塞制动系统是由机械能，液压能或气压能装置驱动的在机械杠杆适合所有的汽车的驻车制动器中使用当踩下制动踏板时，杠杆就会推动制动器主缸的活塞给制动液施加压力，制动液通过油管流入轮缸制动液的压力施加到轮缸活塞以使制动片被压到制动鼓或制动盘上假如松开踏板，活塞回到本来的位置上，回拉弹簧拉回制动片,制动液返回制动主缸，这样制动停止驻动制动器的重要作用是车内无人时，使汽车静止不动假如车内安装的是独立的驻车制动器，那么驻车制动器是由司机手动的控制驻车制动器正常是当车已经停止时使用的向后拉手闸，并把手柄卡在对的的位置上现在，即使离开汽车也不用胆怯它会自己滑走假如司机要再次启车时，他必须在松开手杆之前按下按钮在行车制动器失灵的情况下，手闸必须能停住车正由于这样，手闸与脚闸分开，手闸使用的是绳索或杠杆而不是液力系统防抱死制动系统是使汽车制动更安全、更方便的制动装置，它既有调节制动系统的压力来防止车轮被完全抱死的功能,又有防止轮胎在滑的路面上行驶或紧急停车时的滑动防抱死制动系统最早应用在航空飞行器上，并且在二十世纪90年代一些国内的汽车内也安装了这种系统近来,几个汽车制造商引进了更为复杂的防抱死系统欧洲使用这种系统已有几十年的时间，通过对其的调查,一位汽车制造商坦言，假如所有的汽车都安装上防抱死制动系统，那么交通事故的发生率会减少

7.5%o同时，一些权威人士预测这种系统会提高汽车的安全性防抱死制动系统可以在一秒钟内调节几次制动时车轮上的受力，使车轮的滑移受到控制，并且所有的系统基本上都以相同的方式完毕每个车轮都会有一个传感器,电子控制装置能连续检测来自车轮传感器传来的脉冲电信号，并将它们解决转换成和轮速成正比的数值;假如其中一个传感器的信号不断下降，那么这就表白了相应的轮胎趋于抱死，这时电子控制装置向该车轮的制动器发出减少压力的指令当信号显示车轮转速恢复正常时，电子控制装置会增长制动器的液压这种循环像司机同样调节制动器，但它的速度更快，达成了每秒循环数次防抱死制动系统除了上面基本操作，尚有两个特点一方面，当制动系统的压力上升到使轮胎抱死或即将抱死的时候,防抱死制动系统才会启动;当制动系统在正常情况下，防抱死制动系统停止运作另一方面，假如防抱死制动系统有问题时,制动器会独立地继续运营但控制板上的指示灯亮起提醒司机系统出现问题目前欧洲汽车生产商，如宝马、奔驰、宝时捷等广泛使用的是波许（Bs ch）防抱死制动系统这种系统基本组成涉及车轮转速传感器，电子控制装置和调节装置每个有一个向电子控制装置发出车轮转动情况的信号的传感器，它一般由磁感应传感头和齿圈组成前面的传感器安在轮毂上，齿圈安在轮网上后面的传感器安在后部的监测系统上，齿圈安在轮轴上传感器自身是缠绕电磁核的电线圈，电磁核才线圈的周边产生磁场当齿圈的齿移动到磁场时，就会改变线圈的电流电子控制装置会监测这种变化，然后判断车轮是否即将抱死电子控制装置有三个作用，即:信号的解决，编辑和安全防护信号的解决起到转换器的作用，它是将接受的脉冲电信号解决转换成数值，为编辑做准备编辑就是分析这些数值，计算出需要制动压力假如检测出车轮即将抱死,电控装置就会计算出数值向调节装置发出指令调节装置当接受到电子控制装置的指令后，液压执行装置会调节制动轮缸的液压的大小调节装置能保持或减小来自制动主缸的液压,而装置自身是不能启用制动器的这种装置有三个高速率的电磁阀，两个油液存储器和一个带有内外检测阀的传动泵调节装置中的电子连接器隐藏在塑料盖下每个电磁阀都是其独立控制的，并作用于前轮后部的制动轮缸受到一个电磁阀控制，并依照---的原理进行调节当防抱死制动系统运营时，电子控制装置会使电磁阀循环运作，这样既能收回又能释放制动器的压力当压力释放时，它会释放到液压单元前部的制动器电路有一个单元存储器低压存储器，它在低压下存储油液，直到回流泵打开，油液流经制动轮缸进入制动主缸s y s t e m.S ho e s andpads are p u shed by t he slave c y1i nders t o c ontac t the“drums andr otors“thus causingdr ag,wh ich hop e fu11yslows the car.The typ ica1br ake s ystemc o nsists o f di s k brakes infr o nt a nd ei t her dis ko rdr um b r ak e s in th e rearco n n ectedby a system of tubes andhoses thatlink th e brakea teachw h eelto th e m a stercyl i nd e rFi gure.B asically,all carb rakes are friction bra kes.Whe n the dr ive r a p p liest h e b rake,t he con trol devic eforces b rake shoes,o rpad s,again st the rotat ingb rak e d r um or disk s atwheel.Fr ic tio nb e twee n th e sh o e s or pads a ndt h e d r u ms o rdisks then s1o ws or stopst hewheel soth a t th e car i sb raked.In most mod e r nb rakes ystemssee F i gur e

15.1,t her e is a fl u i d-f i11e d cy1inder,c al1e dmaster cyli nd er,whi ch c o ntai n stwo se p a r a te s e c t ion s,there i s a p i s tonin eachsection andboth pi stonsar econn ec ted toa br akepe dali n the driverscomp a rtm ent.When the br ake is p ushe d d own,br ake flu idi ss entf r om t he ma s te r cylinder to the w h e els.A t the whe els,t hef1uid p ush e ss ho e s,or pad s,ag a inst revolvin g drums ordi sks.The frict i on be t w e en the st a t i on a ry s hoes,o rpads,a ndL h e rev o Ivi n gdru ms ordi sk sslow s and stop s them.Th i s slows o r stops the revolvi n g wheels,which,i n t u rn,slow o r stop t h e car.The bra kef1u idrese rvoir i son t o po f the mast erc yli nde r.M ost c ar s todayhave a t ranspar entr r ese rv oirso thatyou ca n see the levelwi t hout o pe ning th e cover.The brake f luidle vel willdr op slightly as the b r akep a dswear.T his is a no rm a1co ndi tion a ndno causefor concern.If the1e veldr opsn otic ea b lyove r as hort pe r i od of tim eo rg o es do wn to abo u t twot hirdsf ull,have yo urbra k es ch eckeda sso on a s pos sible.K eep the re s ervo i rcov e red exceptfor the am o unt o ftime you nee dto filli t and neve r1e ave a cam of brakef1uid unco vered.Br akef1u i d mustma i nt ain a very highbo i1i ngp oi n t.Exp os u re toai r will ca uset he flu i dtoabsorb moi s turewhich will1owe r tha t boil in gpo int.The brakef1uid tr av elsf rom the mast erc ylinderto thew h eelsthroug ha s er i es o f st eeltubes andrei nfor c ed rubb er hos es.Rubber hos esa re only u sed inplaces thatrequ i re flex ib ility,such a satth e front w h ee1s whichmove up an ddown a swe11as steer.The rest o f th esys t em us esn on-corrosive sea mles ssteel t u bin gwit hspe cial fi tti ng sa t allattachmen tpoint s.I f aste el1i ner eq uir esarepai r,th ebest proc edure isto rep1ace the competeline.I fthi sis notp r a ctical,a linecan berepair e d usingspec ia1sp1ice f itti n gs t ha t are madefo rbr ake sy st emr epa ir.You mustne ver usecopper tubin gto repair a brake s ystem.They are dang er ous andi11eg aL Drumbrake s,it consists of the brake drum,a ne xpa nde r,p u11b ack spri n gs,ast ationary bac kp1ate,two sh o eswit h f ricti onlinings,and an chorpins.The stati onary bac k pl a te is s ecured t o the flange of the ax leho usin g o rto t h estee rin gknu ckle.Th e brake dr umi smo u nte donthe wheelhub.Th ere i saclear anee betwe enthe innersurf ace ofthe drum and thesh oelini n g.To applybr akes,t h e driverp u she spe dal,t heexpa nder expand s the sho es andpr ess esthemt o the drum.F rictionb etw ee nt hebra ke drum andt hef r iction1i nin gsbr akes thewheels andth eve hicle st ops.T o re1e as e brakes,the driver r e1e as e thepeda1,the pu11back spring retr acts theshoesthuspermitt i ng fr eer ot at ion ofthe whe e Is.Disk brakes,i thas a m etai diskinst e ad ofadrum.Aflat shoe,o rdi sk―brake pad,i slocated oneac hsid eofth edisk.T heshoess qu ee zethe rotatin gdisk tost optheca r.F1uid from th emaster cy1i nderforces thepis t o nst omove in,towa rdt hedi sk.T hi sact ionpushe s the friction padst ightlyagain stt he dis k.The f rictionbetween t he shoesand di sks1o wsand stops i t.This p r ov idest hebrak ingaction.Pis tons aremade of e i th er plastico rme t al.There ar eth reegeneral typesof di sk brakes.T heyare the floati ng-cali pertyp e,thefixed-c alipert ype,and thesliding-cali p erty pe.Flo at ing-calip er ands liding-cali perdiskbra kes us eas ingle piston.Fixed-c aliperd iskbrakes havee i th er two or f ou rpi s tons.The brake system assemb1ies are actua tedby mec hanical,hydraulic orpneumatic devices.The mechanic allevera g e i s use d in th epark ingbra kesfitted inal1au tomo bile.When thebrake pedal i sdep r ess ed,ther od pushes thepist on ofbr ake mast ercy1ind er which press esthe fluid.T hefluidflows through the pipelines tothepow er brake unita ndthen tot hewhee1cylin der.The fluidpressureex pands thecy1ind erpis tons thus pr e ssing the shoesto thedrum ord isk.If thepedal is released,t hepiston returnstot he initial positio n,thepu11b acksp rings retr acttheshoes,thef1uid is foreedb ack tothe master cylindera ndbraking ceases.T hep rim arypu rpos eof thepark i ngbrakeisto ho1dthevehic1estationary whileit isu nattend ed.Th epa rkingbrake ismec hani callyoperate dby thedriver wh e na separateparking braking hand1e verisset.The handbrake isnorma11y used whe nthecarhas a1r ea dysto ppe d.A leverispu lied and the rearbrakesarea ppro ach ed an d1o cke dinthe“on posi tion.T heca rma ynow be1e ftw ithoutfear ofits r o11ingaway.When thedri ver wan tsto move thecaragain,he mustp ressa button b ef ore the1evercanber eleased.The handbrake mustalso beable tostop the carintheev e nt ofthefootbr akefailing.For this r eason,itisseparate fromthefoot br akeus esca bleo rro dsinsteadof thehydrauli csystem.An ti-lock BrakeS ystem Anti-lock brakesys tems makebrak ing safer and mo rec onveni ent,Anti-1o ckbrake s ystem smodulate bra kesystemh ydrau1icp r essu re topreve ntthebr akesfrom loc k ingandthe tires froms kiddingon slippery pavemento rd urin ga panic stop.A nti-lock brakesy stems have beenus ed onai rcr aftfo ryear s,a ndsome domest icca r were of fere dwith an earl y form of anti-lock br akingin1a te1990s.R ece nt1y,severalautom ak ersha ve introd u cedmore soph istic atedanti-lock system.Inv estig ation sin Europe，where anti―lock braking systemshavebeena vailablefo ra dec ade,have1edone manufac ture to statethat the numb erof traffic ac cide ntscould bered u cedby sev enand ah alfper cent i fa11cars hadanti-1o ckbra k es.So some sourcesp redictthat al1cars willoffer anti-lock brak estoimpr ovethesafety ofthecar.An ti-1ock sys ternsmodu latebrake applicationf orcesev era1time spe rsec ond tohoi dthetiresata contr o liedamou ntofslip;a11sys tem saccompl isht his in basic allythe same way.One or more sp eedse n sors gen era teal temating current signalwhose frequencyinc reaseswith the wh eel rotatio nals peed.A nele ctroni ccon trol u nit contin u ouslymoni to rsthes esign a Is andifthef re quencyofa signa1dr ops too r api dly indicatingthata whee1is ab outtolock,the contro1unit ins tru cts amodul a ting deviceto reduce hydraulicp res suretothe brake atthe a f fecte dwheel.Wh en senso rsi gn alsin dicate thewheel isagain rotatingnormall y,the contro1unit allowsin crease dh ydra uliep ressu retothebrake.This release-a pp lycy cle occ ursseveral ti meper secondto pumpthebrakes1ike adri ver mi g htbu tatamu chfa sterrate.In addition to their basicop erat i on,a nti-1o cksysterns havetwoother thingsincommon.Fir st,they do notoperat eun til the brakes areappl ied withenou g h forceto1o cko rne arly1o ck awheel.A tal1other times,thesystem stands read ytofunctio nbut doesnot interfere withno rma1braking.S econd,iftheanti-loc ksys tem fail inany way,thebrakescon tinueto operate withoutanti-loc kcapabi1it y.A warningli ght onthein strumentpanel ale rts thedriv erwhenaproblem exis tsin theanti-1o cksystem.The curr ent Boschcomponent Anti―1ock Braking Systern ABS II,isa sec ondg enerat ion desi gn wi Id1y usedby European aut omakerssue has BW M,Me rcedes-Ben zand Porsche.ABSIIsystem consi stsof:fourwheel speedsens or,e1ectr on icc ontr olu nitandmod ulator assembl y.spe edsensoris fi ttedateach whee1sends si g nalsabo utasensor unitand agear wheel.T he frontsen sormounts tothesteering kn uckleand itsg earw hee1ispressedon tothe stubaxle tha tro tates withthewhee

1.The rearsensormounwhee1rotationto control unit.E ach speedsen sorconsist softstherea rsus pensionmem berandit sge arw heel is pressed ontotheaxl e.Th ese nsor itselfisawind ing withama gneticcore.Th ecor ecreatesamagnetic fie1daround thewind ing,a ndasthet eethofthe gea rwhee1move through this field,ana1t ernating currentisind ucedinthe win ding.The contro1unit monitorsthe rateo changein thisfrequency todetermin eim pend ingbrake locku p.The control unisfunc tion canbe divided intot hreepart s:signal pr ocess ing,1ogic andsafet yci rcu itry.Th esign a1processing sectionisthe convertertha trecei vestheal t erna tingcurr ents ignaIsform the speedsen sorsandco nvertsthem intodigital formfor the1o gic s ection.The1o gicsection thenanalyz esthed igi tizedsign alsto ca1culate anybrakepressurechan ges needed.I fimpe ndi ng lock upissensed,the1o gicsec tion sends comman dstothe modu1at or assembly.Modula torassem bly Thehy drauli cmodulat or assembl y regulatespressur etothewheel brakeswhen it rec eivescommands from the con trolutu it.The modu1atoras sembly can maintainor reducepre ss ureover the1e velitreceiv esfromthemaster cylin der,it alsocan neverapp lythebrakes byit sel f.T he mod ulatorass embly consistsofthre ehigh-speed electrie sole n oidvalves,t wofluidrese rvoirs andaturn delivery pu mpequi pp edwit hi nletand outlet check valves.The modula torelectrica1c onnectorand contr oilingr elaysare conc ealedund eraplastic coveroftheassembly.Ea chfr ontwhee1isserve dby e1ect ricso1enoid va Ivemodu1ated in dependently bythecontro1unit.The rearbrakesare ser vedby asingle solenoid va1veand modulatedtog ether usingthese1e ct―low principle.D uring anti-braking systemo peration,thecontro1unit cyc1esthesoleno idvalves toeit herho1d orrelea se press urethebrake lines.When pres sureisre1eas edfromthebrakelines duringant i-braking op eration,itisrouted toa fluidreservoir.There isone reservoi rforthefrontbrakecir cuit.T hereserv oirsare low-pressureaccum u1at ors thatstore f1u idunder s1ight springpressure unti1thereturn deliverypump can return the fluidth roughthebrakeline stothemastercylinder.汽车制动系统制动系统是汽车中最重要的系统假如制动失灵，结果也许是损失惨重的制动器实际就是能量转换装置，它将汽车的动能（动量）转化成热能（热量）当驾驶员踩下制动踏板，所产生的制动力是汽车运动时动力的10倍制动系统能对四个刹车系统中的每个施加数千磅的力每辆汽车上使用两个完全独立的制动系统，即行车制动器和驻车制动器行车制动器起到减速、停车、或保持车辆正常行驶制动器是由司机用脚踩、松制动器踏板来控制的驻车制动器的重要作用就是当车内无人的时候，汽车可以保持静止当独立的驻车制动器一踏板或手杆，被安装时，驻车制动器就会被机械地操作。