2023年毕业设计论文外文文献翻译要求及封面.docx
杭州电子科技大学毕业设计(论文)外文文献翻译液压制动器基础翻译(1)题目有用的产品翻译(2)题目机械学院 车辆工程指导教师0 t her pa r king systems incl u de s p r i ng ch a mb e rs, like t hose used on a ir-bra k e systems. Th es e are spri ngeng a ged, but a re di sen g age d by hyd r au 1 ic pre s sure inst e a d o f air.ANTIL OCKOn m a ny hyd r a ulically braked ligh t -duty t ruck s z antilock b r a kes are u s ed on the rear wheels t o p res e r v e bra kin g s t a b i lit y when these vehic 1 es are ligh 11 y loa d e d . Front and rear-w h ee 1 an t ilock is u s u ally an option, ex c e p t for vehicl e s ove r 1 0, 0 00 pounds GVWR, which are re q uire d to ha v e steer and dr i ve-axle an t ilock.In cur r e nt hydr a u 1 i c antil o ck sy s t em s , a dump v a Ive releases pre ssuri z ed hydra u 1 i c fluid into an ac c u mu 1 ator i n th e event of a n impending wheel lock u p .An electronic co n tr o I box receives spee d s ig nal (s) fro m sen sors i n the t r a n smission and/or a t the whe e Is. w h en the brak e s a r e a p pl i e d z the co n tr o I box senses the deer e ase in r e ar wheelspeed,andacti vates the dum p v a 1 ve (s) if t h e ra te o f d ec e I e ra t ion exceeds a pr e dete rm i ne d limit.Th e con t r o 1 b ox e ne r gi z es t h e dum pv a Ive with a seriesof rapid pulse st oble e d-off wh e el hydraulic p ressure. Contin u ingi n ant i 1 ock m o de,th e dump v a 1ve is pulse d to k eep th e wheels r ot a t ing, while maintai n in g contro 1 led d ecelera ti on.At th e end o f such a s to p , th e val v e d e -ener g i zes a n d any f 1 uid in th e accumulator is retu r ne d to the m a st e r cylinder. No r m a I br a k e o p era t ion res umes. FOUNDATION BRAKESF o undat i o n brak e s i n hydr a u 1 ic systems ca n be e ither d rum or disc. In many ap p 1 ic a t i ons, di s cs are u sed o n the fron t ax 1 e an d drums on the rear.Drum b r a k es are s a id t o be se 1 f-energizin g . T h at's b e cau s e w h en t h e br a ke s hoes expand and c o n t a c t a rotati n g drum, the leading, or f o rwa r d z brake sh o e i s p u s hed ag a i ns t the t r a il i ng shoe b y the force o f t he mo v i ng d r um. Thi s r e s u 1 ts i n higher lining-to-d rum press u r e tha n wo u I d be p r odu c ed b y the wh e el c y li n d er al o n e.As bra k e lin i n g s wear, t he sh o es peri o d ically must be movedc I o ser to t he drums t o ensure pro p er co n tac t duri ng br aking. Wh i Ie some old e rdrum b ra ke assembli e s a re ma n uall y adj u s t e d,mos t ar e a u toma t ic. The s e u se a starwheel o r r a tchet assemb 1 y, w hich s e nse swhe n t he w h ee 1 cy 1 inde r has trave 1 edbeyond i t s norm a I s t r o ke, and exp a n ds t h e p ivot p o i nt a t t h e other e nd of th e brak e s ho e s.I n add ition to b ei ng one of the f r i c t ion e 1 ements, t he b r ake d r um or r o tor al s o a c ts as a hea t sink. It m u st rap i dl y a b s or b h e at dur i ng brakin g, and h old it unt i I it can bedi ssipa t ed into the air. The hea vier a drum or r otor i s, t h e more heat it can hoi d .Th i s i sim p ortant, s inee the ho t t er the brake linings get,th e m o re sus cepti b 1 et h ey areto heat f ade. He at fa d e is in d u ced by repeated hard sto ps and r e suits i nre d ucedlin i n g-todr u m/rot o r f r iction and i n c reas e d vehic 1 e sto pping d i st a n ce. As a r ule, h i ghquality lin i n gs wi 1 1 d ispl a y 1 e s s he a t fade than infe r io r ones. Al s o , di s cb r a k e s ar e f a r mo r e resis t ant to h e a t fad e thand rum brakes.An o thert yp e o f f ade that br a kes are suscept i ble to i s wat er fa d e. D r um b r a ke s, with th e ir I a rge sur f a c e a reas, app 1 y fewer pound s per square inch of for c e betwe e n 1 ining a nd drum d urin g a s t o p th a n di sebrakes. This, ad d ed to th e d r um's wa t e r - r e taini n g sh a p e , prom ote s hy d ro pl a ning b e twe e n shoe an d drum unde r wet con diti o ns. T h e res u It is great 1 y i n creased stopp i ng d ist a nee.D isc bra k es, with their smaller frictio n s u r fac e s and high clamping for c e s z do a good job o f w i ping water fr o m ro t o r s, and di s pl a y li t t Ie re d uct i on in s t opping c a pabil i t y when wet.有用的产品气动钢瓶液压制动基础空气制动系统得到更多的关注,但更多的车辆上安装液压制动器。了解它们 是如何工作的,是安全,具成本效益的诊断和修复的第一步。有没有想过为什么不能只是其中的一种制动?这是由于空气和液压制动器,使一 个或某些应用程序的其他抱负的经营特色。重型组合的车辆,空气是明确的选择, 由于将需要大量的液体阿卡迪亚所有分泵。止匕外,充满液压油与制动分泵和软管 的将是混乱的。但对于轻型和中型卡车直应用,液压制动器提供的优势涉及: 制动感觉-那就是,踏板越往下压,努力增长;高线压力,允许使用更轻,更 紧凑的制动组件;A更少的初始费用,由于用更小和更少的元件;卫生,液压制动器是封闭的系统;A 易于定位泄漏,由于液体是可见的。液压 制动系统有更多的排列,比在空气系统中发现,但都基本相似。液压系统所有的液压制动系统包含流体水库,主缸,液压,液压管路,对制动器进行加压流 体的软管和一个或多个轮缸(S)对每个车轮产生。分泵扩大流体压力下,迫使制 动蹄对鼓的内侧。假如使用盘式制动器,卡钳与不可分割的气瓶打击转子时施加 压力。4由于车辆必须可以更迅速,它可以加速到停止,需要大量的刹车力。因此, 必须减速刹车产生的马力的发动机作用多次。为了发展须持有对鼓或盘制动器衬 片的力量,实现受控减速,这是要乘原始的力量施加在刹车踏板。当使用液压系统,机械杠杆是在脚踏板联动。然而,不同分泵或卡尺直径的直径, 关系到主缸内径,提供了一个额外增长的比率。液压系统中,各分泵交付的压力, 直接影响由活塞地区。例如,假如一个轮缸活塞面积2平方英寸,另一个活塞面 积1平方英寸,系统压力为400磅,2平方英寸的活塞将针对制动器推一个迫使 80 0磅。1平方英寸的活塞施加一个4 0 0磅的力量。总泵和分泵的地区之间的 比例拟定在轮缸活塞的力量倍增。为保持在头脑,直径较大的轮缸的,更流畅, 必须提供由主缸行程较长的硕士转化。请记住,直径较大的轮缸的,更流畅,必须 由主缸提供,以填补它。这意味着进入一个较长的主缸行程。假如主缸孔直径增 长和相同的申请仍然有效,更少的压力将在系统的开发,但一个更大的轮缸活塞 可以用来实现在轮缸所需的压力。显然,必须更换主缸,轮缸或卡尺相同的设计, 并作为原单位承担。液压系统中,各分泵交付的压力,直接影响由活塞地区。例如,假如一个轮缸活 塞面积2平方英寸,另一个活塞面积1平方英寸,系统压力为400磅,2平方英寸 的活塞将针对制动鞋推一个迫使800磅。1平方英寸的活塞施加一个400磅的 力量。总泵和分泵的地区之间的比例拟定在轮缸活塞的力量倍增。液压制动系统 分割的系统,涉及两个谨慎的制动电路。一主缸活塞和水库是一个单独的活塞及 伺服制动器上的其他桥(S)的水库,用来驱动一轴刹车。虽然罕见,一些轻型 制动系统分裂对角线而非桥桥。分割系统的因素是,假如一个液压回路泄漏的发 展,将停止车辆。当然,不应当被驱动的车辆远超过必要的制动系统修复。当液 压回路发生故障,压力差开关感官两个电路之间的不平等的压力。互换机包含由 弹簧片,并在每年年终电触头位于活塞。从一个液压回路中流体的压力提供压力 差开关的一端,并从其他电路的压力提供应另一端。随着压力的一个电路,其他电 路的正常压力,迫使活塞的失效一边,关闭的接触,并照亮仪表板警示灯。动力辅 助a协助电力单位,或助推器,减少运营商的努力,在刹车踏板。真空助力器,轻型 汽车的流行,使发动机真空隔阂一侧,对对方的大气压力。一个阀门,使真空作 用于刹车踏板的行程中的比例隔阂。这有助于踏板的努力,并增长对制动液的压 力,无需过度增长在踏板努力。其他类型的助推器使用液压压力-无论是从车 辆的动力转向泵,或从一个单独的电动泵,或两者兼而有之 一 协助刹车踏板 被踩下踏板作用,阀门液压升压室申请增长的压力在增长主缸活塞。有些系统使 用真空和液压助力。在其他系统中,从船上压缩机的空气压力产生液压系统的压 力。阀杆液压制动系统中常见的阀门涉及:a配比,或压力平衡阀门。这些限制液压 比例后轮刹车系统压力达成预设的高阻值。提高前轮/后轮在高速制动的制动平 衡时,一些车辆的前后重量转移,并有助于防止后轮配料阀高度传感器。也就是 说,他们调整后轮制动压力,在车辆荷载的响应。随着车辆的负载增长(减少高 度)液压后轮刹车是不允许的;测光阀门。这些保持了前盘式制动器的压力,让 后轮鼓式制动蹄克服返回弹簧的压力,使接触后鼓。这可以防止锁定在湿滑路面 上的前刹车灯制动应用。这些阀门不来硬制动过程中发挥作用。泊车盟亭车功能的液压制动系统之间的差别很大。许多轻型车辆使用与后轮鼓式 制动器杆和电缆相配合,逐步加大杆或脚踏拉电缆,这反过来,拉杠杆总成,每 个后轮结束的客运车类型。杠杆迫使制动蹄外,他们对鼓机械棘轮被释放,直到其他泊车系统涉及弹簧腔,像那些用于空气制动系统。这是弹簧控制,但由液压脱 开而不是空气。防抱死A许多轻型卡车液压制动,防抱死制动系统上使用的后轮保持轻载时,这些 车辆制动稳定性。前面和后轮防抱死通常是一个选项,GVWR超过1 0,000磅 的车辆,这是需要引导和驱动桥防抱死关闭。在当前的液压防抱死系统,转储阀 释放压力到一个累加器在即将车轮锁死的情况下液压油。a电子控制箱接受来自 传感器的传输和/或在车轮速度信号(S)。当施加制动,控制箱检测在后轮的速 度,减少和激活转储阀(S),假如减速率超过预定的限制。碓制箱通电一系列流 血轮液压快速脉冲的单向阀。继续转储阀是脉冲在防抱死模式,以保持车轮转动, 同时保持控制的减速。在最后的停止,阀门的激励和累加器中的任何液体返回到 主缸,恢复正常的刹车操作。基础刹车在液压系统的基础制动器可以是鼓或光盘。在许多应用中,光盘上使用前轴后方 的鼓。鼓式制动器说是自激。这是由于制动蹄扩大和联系一个旋转的滚筒,引导 或向前制动蹄被推向对刹车制动箍由移动鼓的力量。这个结果在更高的衬里鼓比 将仅由轮缸产生的压力。A随着制动器衬片的磨损,必须定期移近鼓,以保证在制 动过程中适当的接触。虽然一些旧的鼓式制动器总成,手动调整,大部分都是自 动。这些使用一个星轮或棘轮大会,这感官分泵时已超过其正常行程前往,并扩 大在另一端的制动蹄的支点。除了摩擦的元素之一,制动鼓或转子也充当散热器。它必须迅速制动过程中吸取 的热量,并保持它,直到它可以将空气中消散。鼓或转子较重的是,它可以容纳 更多的热量。这是很重要的,由于制动器衬片热,他们更容易受到热衰退。热衰 退是诱发反复的硬盘停止和结果的减少鼓形轮子连接的摩擦和增长车辆的制动 距离。作为一项规则,高品质的衬里,将显示低于劣质的热褪色。此外碟式刹车 比鼓式制动器耐热褪色性能更好。另一个褪色的类型,刹车容易褪色水。鼓式制动器,其表面积大,在安全范围内 比盘式制动器每平方英寸之间需要更少的衬力和鼓力。加上鼓的保水的形状,鞋 和鼓之间的潮湿条件下促进水面滑行。结果是制动距离大大增长。盘式制动器,具有较小的摩擦表面和高夹紧力,做一个良好的工作从转子擦水,并 显示在潮湿时停止能力几乎没有减少。HYD RAUL IC BRAKE BAS ICSAir b rak e s get more a t t e nt i on, b ut hyd r a u lie bra k es a re inst a He d o n m o re v eh i cles. Underst a ndin g how they work i s the first st e p t o s a fe, co s t-e f fective di a gno s i s and r e p a ir.E v er w o nd e r why t here can't be ju s t one k i nd of brake? It's b e c au s e ai r and h y draulic b r akes e ach have op e rating chara c te r is t ics t h a t ma k e o ne or t h e o t h er ideal for c e r tain applic a t ions.In h e a vy-du t y co mbinat i on vehi c les, ai r i s th e c 1 ea r c hoice b e c a use of th eI a rge volum e of liq u id that wou 1 d be n e ede d to a c adia a 1 I the w h eel cylind e rs. Plus, de a ling with glad hands and h os e s f i 1 1 ed with hy draulic fluid w o uld be me s s y.But for ligh t and med i u m-d uty str a i g ht-truck a p pli c ati o n s, hyd r au 1 ic br a kes offer ad v antag e s i n eluding:B rake feel that is, as the pedal i s p res s ed farther d o wn, effort i n c r e ases;High line pr e ssures, which p e rmi t the u s e o f I i g ht e r, more comp a ct br a k i ng components;Lessi ni tial ex p ense, d ue tosmalle r and f e wer components ;Clea n1 iness hydraulic brake sa re c 1 os e d sys t ems;Ea s eof Io ca t in g Ie a ks, sine ef 1 u i d is vi s ib 1 e.The r e ar eman y more p e r mutationsof h y dra u lie brake syst e msth an foun d in ai r systems, but a II h a v e ba s i c sim i I a ritie s .THE HYDRAULIC SY STEMA 1 1 hyd r a u lie b r ak e systems co nta i n a fluid rese r voi r , a mast e r c y linde r , which produces hydrau 1 ic pressure, hydr a uli c linesand hos e s t o carry pre s su r i z e d f I u id to th e br a ke s , and o n e o r mor e wheel c y lin d er (s) on each wheel.T he whee 1 cyli nde r s expand u nder fluid p r e ssu r e z an d f o rce the br a ke sho e s a gain s t th e insi d es of the d r um s . I f disc brakes are used, c alipers, with integral c y I i n ders, cl a mp down 0nthe rotors when pr e ssure is ap p lied.Because a ve h i cle must be able to s top much mor e quic k ly than i tcan acc e lera te, a trem e n do u s amount of br a king fo r c e i s needed. The r ef o re, t he retarding h o r s ep o w e r gen e ra t ed by th e bra kes must b e several times th a t of t h e e ngi ne.I n orderto d ev e lop the f o r c es required t o h old th e bra k elinin g s aga i nstth edrums ord is csz a nd toa chi e ve cont r oiled de c e lera t i on, it isne c essaryto multi p 1 yth e origi na 1 force appl i e d at the b rake p eda 1 .Wh e nahydra ulicsys t em is use d , th e only mech a nical1 ev e ra g eis i nt hefo o tped a 1 li nkage . H o weve r, varying the d i a meter of t he wheelcylind er s o rca1 iper diam e t e rs, in r elat i o n t o t he m a ster cy linde r bore diamet e r, provides an a d d i t i on a I i ncrease in r ati o .I n a hydraul i c syst e m, the press u re d e 1 ive r e dbyt hev a ri o us wheel cylinder s is di r ectly affected by t he a r eas of th e ir pist ons. Fore xample, i f o newheelcylind e r piston has a n area of 2 s q ua r e inches,andanot he r p iston has a narea o f 1 squar e inch, and the s y stem pres s u r e is 4 00psi,the 2-s qu a r e- i nch p iston will push aga i nst th e b rake shoes withaforce of 80 0 pounds. The 1squa re-inch pisto n wi 1 I exer t a for c e of 4 00 pounds. The r a tio be t we e n th e a r eas of the m a s t er cy I i n d er and the whe e 1 cy 1 ind e rs dete r m i ne th e mu 1 tip 1 ic a t ion of for c e at the wheel c ylind e r pist ons.Ke e p i n mind tha t the la r ger a whe e I c y I i nd er's diameter, the more f I u id m us t be s upp 1 i e d by th e ma s t er cyl i n der to fill it. Thi s translat e s into a 1 o n g er m aster- c ylinder stroke.If the m a ster cyli nd er bore d iameter is inc r ea s e d and t h e ap p 1 y ing force rem a i ns t he sa m e , 1 ess p res s u r e w i 1 I b e devel oped in t h e syst e m, but a 1 ar ger whe e 1 c y 1 in d e r pi s ton ca n be used to a chie v e the d e s i red pr e ssu reatthe w hee 1 cyli nder. Obv i o n sly, a r e pl a ceme n t m a st e r c yli n de r z wheel cylinder or c a li p er mus t b e of the sam e de s i g n a nd b ore as the o r iginal un i t.Hyd r a u lie bra ke sy s tem s a r e s p lit sy stems, comp r isi n g two dis c ree t bra kin g c i rcuits. One master- c y li nder p i ston and reservo i r is used to ac t u a te the brake s on one axle, with a separate piston and reservoir actua t ing the bra k e s o n the other a x le(s). Al t h o ugh rare, s o me light-duty brake sy s terns are split d iag o na 1 ly rat her t h an axl e b y axle.Th e rea s on for the spli t system is that if a lea k develops in one hy d ra u 1 ic c ir c u it, the othe r w i II s t op the v e hicl e . Of c o urse, t h e vehi c Ie shoul d n't be drive n any f a r ther than nec e ssary to hav e th eb r ake s y stem repaired.When o ne of the hydraul i c c i rcuitsf ails, a pressur e -differ e ntia 1s witchsense s une qu a I pre ssure b etween t he t woci r cu i ts. Th e sw i t ch cont ai nsapistonlocat e d by a ce nteri ng s p ring an d e1 ectr i cal c ont a cts at eachend.Fl uidpressuref rom one h ydra u lie circuit is su p pl i e d to one end o f th e pre s suredifferenti a I s w i tch, and p ressu r e from the o t he r circuit is su p plied t o the other e nd. As pre s su r e f a 1 Is i n one c ircuit, the o t h er circuitz s normal pressu r e for c es t he pist onto th e ino p era t ive s i d e , clos i ng the co ntac t s a nd il 1 u minatin g a da s h bo a rd war n ing 1 ig h t.POWER ASSISTPowe r as s ist units, or boosters, r e duce op e r a tor e ffort at th e brak e pedal. Va c u u m bo o s ter s, po p ular on 1 ightduty veh icl e s , make u s e of an e ngine v a cuum o n o n e side of a d i a p hra g m, a n d atmo s ph e r ic pr e ssure on the o t her si d e. A valve allows the vacu u m to act on th e diaphr a gm in pro p ortion to b rake ped a 1 t r a vel. Th i s a s si s t s the p e dal ef f ort, and all o ws in c r eased p r es s ur e on the br a ke f 1 uid, wi t h o ut an und u e i n crease i n p e dal e f fort.Other ty pes of b oos t ers use hydra u lie pressure either f rom th e v e hide' s power steerin g pump or f rom a s eparat e elec t ri c p u mp, or b o t h to as s i st p e d a I e f f o rt. As th e br a k e p eda 1 is de p r es s e d, a v a Ive i n ere a s es hydraulic pr e ssur e i n a boost c hamber to a p ply incre a sed pres s ur e to the m a s ter cyl i nder pist o ns.Some s y st e ms u s e b o th vacuum and h y draul i c as s ist. In other s yst e ms, air pressure fr om anonboard c o mpressor i s u s ed to gene rate hydraulic sy s t em pre s sure.VALV I NGValves co mmon 1 y f ou nd in hydraul i c brak e systems incl u d e : Proportion! ng, o r pressure-ba 1 ance val v es. These r e s tr i c t a pe r cen t a ge o f h yd r aulic pressure to t he rear b r a ke s when s y s tern p ressu r e reach e s a pr e s et high v alue. This i mpro v esfr o n t /rear brak e b a lane e d uring hi g h- s p e ed braking, when s o me of a v e hide's r ear wei g h t i s tran s ferr e d forw a rdz and helps pr e v e nt rea r -wheel I o c kup. Some pro p orti o ning valves a r e hei g ht- s ensing. That is, the y a d just rea r - b r a ke p ress u r e in respo n s e t o ve h icl e Io a d. As a vehicle7 s 1 oad incr e a ses (deer e asi n g h e ight) more hydra u lie pre s s u r e to th e rear b r a k e s is a 1 low e d; Metering v a Ive s. These h ol d of f pressur e to f r ont disc brakes to all o w rea r drum b r a ke shoes to ov e r c o m e ret u rn s pring pre s su r e an d make c o ntact wi t h t h e rea r drums. Th i s pr e vents 1 ock i ng t hef ront brak e s on s 1 ipper y su r f aces under ligh t brak ing a ppi i c a tions. Thes e v a 1 ve s do not