汽車商務(wù)英語(yǔ)

1、Chapter 1Automobile EngineUnit OneInternal Combustion Engine BasicsThe basicsThe engine is, of oo 山 se, the heart of every car. At the most b 邸 ic Ee vel, the engine devlops 山 e power to move it. This se tion discusses the differ 妞 I 叩 -:s of engines in use, 邸 wen as the fundamental oon.cepts behind

2、 in掄mal comb舊缸o(hù)n e噸 ine.Th.ere a-re many 切 心 血 d v 印 atio ns of automobile engines. The most common叨 汜 is theinternal comb屯 tion engine. It is so named 比ca1.1se co mbustion takes pla忱 in.sid e the engine.The engine is mount,ed to the car frame. An in比mal oombustion eon積比 is liike a container into wh

3、ich we put air 血 d fiuel 妞 d then start them buming. The air 叩 d 加 I is burned irn the e 罵 ine container, or cylinder. A cylinder is a metal tube closed at one end. A rr,ovable plug. called piston, is installed 郵 ide the cylinder. There is a small space be 兇 een 如 p 岱 ton t1p and tlhe top o f the cy

4、linder. This sp氐 C; called由e comb-u.&1ion cha mber, is where 中e 111:m il!l g 也 k $ pl.ace. If severa l如 ps of 芘沁 line are placed into this spa心, imd the pisto:n is pushed up in the cylinder, the g.asolinc 卻 d a江m the combu勸Qut engines 吶 lh f0田 歸 Ivespe:r cylinder have運(yùn) omeincreasingly popurar in rCn

5、. Die沁!engines歸 e he CJ principle, and these engfnt$ have much. hi沙er oompressi()n than SI enginesCylinder ar r11nge me-n.tThe most common arrangementsof en.giae cylinde巧 are in-line, V叩 e, and oppo:sed， An in-line engine has the cylinders mounted vertically aind positioned: in ai 1i:ne d四tly behind

6、 each other. V書(shū)type engines. usually ba:.ve 6 or 8 守 linders located in a V formation w心 an angle of 60 degrees or 90 degrees bel.lveen 小e sides of 山e block. Other V叩 e engines hae been used; for example, one manufacturer is now marketinga VIO eogi:ne. 1n an opposed engine, the cylinders缸position.ed

7、 horizontally across的 m each other.Number or cyUo dersEngines are desi即 ed 灼 th 3, 4, S, 6, 8, 10, or 12 cyljoders.3Cycle$Most automotive e:ng:iae s operate on the four-cycle principle. Since the two-stroke engine is lighter and may be desi 驢 ed to produce more power than an equivalent size four-str

8、oke engine, the two-stroke engine may experience wide.spread use in the near 扣 匹 e. All of the big 牡 ree automotive manu位cture-rs h a ve two-s訂oke engirnes under development.Wordscombutison. n 燃燒fundamen也Iadj. 基 礎(chǔ)的 ， 基本 的automob i len. 汽車cylindern. 氣缸，柱面pistonn. 活塞combu勸on chamber燃燒室car frame 汽車車架me

9、tal tu朊金屆圓管movableadj. 可移動(dòng)的CO 皿 動(dòng) ng tod連桿cr缸 kshaftn. 曲軸pis ton pin活塞銷stroken. 沖程flywheeln. 飛輪momentumn動(dòng)噩valven 閥， 氣門(mén)cylinder he.ad氣缸蓋OV 呻 ead valve頂置式氣門(mén)camsha幾 Iii, 凸輪軸叫 ve train氣門(mén) 組single overhead e,amshaft單頂置式凸輪軸如al overh牡 d camshaR雙頂置式凸輪軸cylinder block氣缸體ignitionn 點(diǎn)火，點(diǎn)燃spark pllllgn. 火花塞electro

10、den 電 極叩 .ivalent adj. 相等的，相 當(dāng)?shù)?，同意義的Notesl. T 拓 s section discusses the differeJlt types of engines in use, as well 叢 the fundamen 叫concepts b咄ind internal com usti()n engine. 本節(jié)討論所用的不同類型的發(fā)動(dòng)機(jī)，以及有關(guān)內(nèi)燃機(jī)的基本概念。. lt is so n血 ed 比eause eom加的妞 包k區(qū) place rnside the engin.e. 之所以這樣命名，是因?yàn)槿紵l(fā)生在發(fā)動(dòng)機(jī)內(nèi)部。The middle

11、of the crankshaft is offset曲軸的中部是偏心的Engines with a single camshaft positioned 的 ove the valve train on the cylinder !head may be refelired to as single overhead 也 nshaft (SOHC) engines.采用一根凸 輪軸， 且 凸 輪軸位 千 氣缸 蓋和氣 門(mén) 組 之 上 的 發(fā) 動(dòng)機(jī)稱 為 單頂置式凸 輪 軸 發(fā) 動(dòng)機(jī)ExercisesI. How docs the internal combu.stion engine: wo

12、rk?How are ihe.automotive engines classified?What is the main di的 rence be的 een the SOHC and DOHC?4Reading MaterialHow Does the Engine Work?The engine is the s.(ly.!e:f power that maike s the c 盯 moves . The !burnin g: of gaso line in li,he e ng如c cy血der produces如e power. The power is th.en carri ed

13、 from the engine through the power train to tthe car wheels so that the wheels tum:and the car moves.The fuel system plays a vital part in tb.e power-producin g:process since it supp,lies the gasoline to the en砰 汜 守tinders. In each engine. cy linder, a mixture of gasoline vapor 皿d air enters the cyl

14、inder, the)iston pushes up into the cylinder to c-0mpress the mixture, and then an electric sp吐咖 tes 如 e compres.sed mixture so that the piston is forced downward. Of course, in. 如 engine tlte piston is not blown completely out of the cylinder, 中e p,isto n s皿ply moves up 叩 d down in 伽cylind嚇 勹 1p to

15、 compress; llhe 血 xt 江 e, do 叮 1as the Jlilltu.re bums. The piston s加 ght-Hne motionmust be chang吐 to rotary motion before 八 c:an be used to ;make the 也 r wa eel ro紐tes. A conn氐 tin.g rod and ,a e ra咄 on the engine c,初 kshafl make this ch血 geThe en邸11e valves get 由e bum函 gasoline vapor out oftlhe en

16、gine cylinder 皿d bringing fr邸 hcha屯e of gasoline vapor and air int() 山e cylind er. The詫 are two openin驢，or po芯，in th, e enclose d end of1he cylinder, each containing valve. The valvesare accurately machined plugs on long stems When they 如 clo函 ，or s迎 ted（中at is, moved up into the ports), the ports a

17、re sealed o斤and gas C皿 not pass through 伽s ports. When the valve is open, gas. can pass through the portThe valves are 01;e:n兇 b y cams on the engirne ca畔 aft. The c皿 has a hjgh point, or lobe; every i皿e 由e 氓 m mtates，加 lobe comes around under the valve lifter .and moves it 叩 Wa過(guò) Tihe lifter then ca

18、rries this upw叮d movement through the pUIS比od to the :roc ker 印 TI. The rocker annpivots on its sup 沁 rt and p 匹 hes down on 如 valve stem, causing 山 e valve to move down. that is,to open. After th七 cam has 血 砒 d enough t move thelobe out 伽 m U.Q,der the lifter, the hea-vy valve spri屯Ex.,.u vaN 倉(cāng)心 an

19、d 心1 噸 e portpulls the valve back in1o its s 綽The spring is/ 4 S 凹 僅盧叩 ched to 出 e upper end of the valve stem by a spring retainer arnd lock . The re is a cam for each valve (two cams per cylinder)on 血e engine camsh.aft. The camshaft is driv,e n off the ci皿 Jcs haft by gearsor byspr心 kets 印 d a cha

20、in.When the erntire cycle of events requires four piston strokes (two crankshaft revolutions). the engine is called a four-stroke 氣 cycle engine, or a four-cycle- engine. The four s 訂 okes re intake,compres1;io n, power, a:nd e心a ust._,.On the intake stroke（心shown in Fig. l-3), thefig. 1-3The in切kes

21、troke5in 咄 e valve open, 如 piston moves down, pulled by the rotation of 山 e cranksha 仕 Th is piston mtvemei:it er 包 te$ a p 血 al 鄧 cuum in th cylinder, and air rushes into the cylinder past 伽 in 伍 ke val.ve to 咽 U up t his vacuum. As the air moves tow.ard the cy 加 det, it must pas$ t 址 ough the carb

22、uretor. There it is charged w 心 gasoline vapo:rthat rushes into the cylinder as the piston mov 心down on the intake stroke.A缸r the piston moves down to the bottom dead oimter on 山e intake stroke, the int吐e valve closes. The lobe o :a 如 c a m controlling the in.take valve has moved out 介 om under 加 e

23、valve lifter: Since th.e o 如 r valve is al 沁 clos 吐 ，the upper end of 如 cy1indcr is 沁 iled Now 邸 the piston is pushed up by the rYta血 g cm心 haft, the 皿 灶田 e of air 皿d gasoline va扣頃 at has been drawo into the cylinder is compressed(As shown in Fig. l -4) By th, e time 由e p閣Qn has moved up to th.e top

24、 dead 心 n氏r, tihe mixtuJre is compress 叫 to a s.eventh or 皿 e i加h of its or:igin.al volume. That 岱！如taking a gallon of air and compressing it t()a p-int. The result is higih p蘆 s ure in th,e cylinder.About the time 小 e piston reac 朊 s the top dead cen 應(yīng) on tlle compression stroke, an electric spark

25、o 叩at thescy l:inderspark plug. The s 阰 rk plug is essentially two lleavy wire electrodes: the 叩ark jump between th,e;se elccirodes. Thespark is produced by 由e i鄆 ition system. It ign血d, or set fire to, 如C0叩 res沁air-gasoline-va）可Ollxtu:re心 Rapid combusti.on talcesp lace;high temperatures .a:nd p 芯 s

26、 ure result. At 由 is ins 血 I, the do 叩 ward pr 心 sure oa the top of the piston may 皿 ount to as much as 2 tons. T 加 s powerful p1,1i,b forcs 由 e pis1oo down (As shown in Fig. l5), and a power impulse is transmit to the era吐s加R 加 ough th-e co1111ec ting rQ!l 鈕 d the era咄 / 刁 沺 rkpl叩lntakev汕 e扣tist va

27、lve / / $ 嚴(yán) rk,plugFig. 1-4 Thecompr-e 函 郖 如 okeFig, 1-5 Thc mwer 沁 okThe pis 的 n is: for 濕 do wn by th.e p,essure of the burning gasoline vapor during the power 泣 oke, Wh:en the piston reaches the bottomdead cent,er the exhaust valve opens. Now, as t!he piston starts ba.ck up again, it forces the b

28、urned g 邸 es from the cylfoder (As showrn in Fig. 1-6). By the6time the piston 缸 re.aches 血e top dead center tile cylinder is cleared of 中e bum必 g邸 es The c汕 a應(yīng) t valve closes and the intak.e valve opens. Then, tile piston s但tis back down. again on 小e next intake 玵 ke. The four cycles, or pi叩 n stro

29、kes, are con血 uously repea伈d w叫 e the engine is mm血g,In臼Ko va11/0珈 rkplugCo,nbustioncham歸P悶tmFig. I0 6Toe e.xJ衛(wèi) US,叩 IceExercisesHow does出e 驢soline engine make the ca.r move?Whats the function of the crankshaft?Describe the working process of the engine.Uni t TwoThe Fuel Delivery SystemThe fuel deli

30、very sys tem ,co還 is岱 of all the components which supply the engine with fuel. 加 s inclu.de:i the tank i 困 If, all the lines., one or more fu.el filiers, a. fuel pump (mechanical or electric)，扭 d the, fuel metering components (ca.rb ure應(yīng) or fucl 砌ection system).Fuel 臼nkFuel tanks are oonnally locate

31、d at 中 e 邸 r of the vehicle, although on rear or mid engine vehicles they are usually I心ted at the fro nt. Th e tank contains a fuel gauge sending unit, a filler tube and,on most fuel injected vehicles, a 膽 l pump. In most ta 心 ，there is also a fine mesh screen soc k attached to 中e pickup tube. flli

32、s is us.的 to fil ter out large particles whicih could eas仆y clog the fuel lin偽 ，fuel pump and fuel filterSince 出e advcnt of cm.ission 心 ntrols, tanks 缸 C 岡 uippedw油 a control system to,prevent fuel vapor from being disch 叩 ed into 如atmosphere. A vent line in the 血 k is connected to 扭activat吐 car加n o

33、r charcoal filled 吐 nis比r in thc cn即 e compartment. Vaprs from the tank arestomd in thI勻nis比r, u:ntil they can be p屯-gd later for combustion in the eng血On manycarbureted engines, 比e float bowl is al沁 ventOO to 伽如 i.ste r、.Fuel pumpsMechani cal pu:mpsMechanical pumps:are us 皿 Uy found on c 袖 皿 ted. e

34、ngines or on engines that utilize .a mechanic;al :fuel injection system.Mechanical fuel pumps o:n c 呻 uretedengines are usually mo.Ill 比 d on the side of the engine b 虹 k or cy 血 der head and operated by an eccentric on 血 e 頃 ngine 爭(zhēng)s camshaft. 嚇 e rocker 如of the pump rests against the camshaft e-cc

35、e n 如 ， 印 d as the camshaft ro 芘 tes, ii actuates the rocker 叩 Some engines u.se a pushrod between the rocker arm 扭 d camshaft eccentric 已 Inside the 扣 el pump, the ro-kc:r annis co 皿 ec ted to a flexible di.aphragm. A spring, mounted underneath, rnain1ai 邱pre$s 印 e on 如 e di.ip 缸 砰As 血e rker arm is

36、 act 妞 led, it putils the diap 歸 即down and then releases it. Once the diaphr篤is released, 如 spring pushes it back llp. This continua.I 如 apbragm motion causes a partial vacuum and pre.ssure in the space above the diap 血 鏟 !. The vacu 血 如 ws 伽 e fuel 如 m the tank andl the pr 蕊 sure pushes it toward t

37、he carburetor or injection pump. A check valve is used in the pump to prevent fuel 行 om being pumped back into the tank. Ce 血 m mechanical fuel injection systems also utilize a mechanicwl fuel pump, 叩 ically some die 函e 鳴 印 es 皿 d 呾 ly gasoline fuel injection syste 血 Many of them use a fuel pump ess

38、entiallyidentical to the carbureted fuel systems. Some, however, use a va.ne type fuel pump m-0 皿 led 中 rectly to 讓 e injection pump/fuel distributor assembly. l he injection pump/fuel distribu 血邸 sembly is driven by the timing belt. chain or gears, which:inrum drives the fuel pump. The vanes8如 w th

39、e fuel in through the inlf!l port then squee2e the fuel into a tight passage. Th 七 fuel then ex 瓜pressurized through the outlet port EI.e-cttric pumpsThere are two general types of ellec tric fuel pumpsthe impeller type and 山 e bellows 叩 e. Electric pum!s can be found on all ty 嚴(yán) of fue1 sys t 妞 1s

40、(As sh.own in Fig. 1-7).The impeller type p 血 p uses a va:ne or impell 釘出at is 士iven by 叩 eEec :tric;: motor. These p皿 ps areft.en munted in the fuel tank, thugh th守血sometjm 邸 f0 皿 d below or beside the tank:. The vane.s or impeller draw tbe fuel in through the inlet port thenEl玩 tfical，如 l1 父 torsF

41、ilte,幾 g. 1-7 Fuel pu 叩 氐 embJysquee 兀 the fuel into a tight pa 恕 ge. This pressurizes the fuet The pressurized fuel then exits through t11e outlet port.The bellows type pump is rare. This pump is ordinarily mounted iin the en滬ne compartmentand contains a flexible metal bellows operated by an ,eloct

42、roma驢 et. As th.eelectromagnet is energized, it pulls the m嘩 幾ellows up. This draws the fuel 行om th 邸 k into the pump. When the electromagnei is de-en叩g江”,the bcllows rcturns to i岱 ori.gimal position. A cbtock valve closes to prevent 山 e fuel 阮 m retuming to 小 e tank. The only place for the fuel to

43、go now is through the outlet port.Fuel filtersIn addition to 由 e m 邸 h screen attached to the pickup tube, all fuel systems have at I 也 st one。中 er filter located so mewhere between th.e fu el tank and the fuel metering components. On some models, 止 e filter is pan of the fuel pump itself, on others

44、, it is located i:nthe fuel line, and still others locate 小e filter at the carb-uretor or tltrottle body in!et.CarburetorTile carburetor is, the most complex part of the entire fuel ffYStem (As shown in F 屯 i -8). Carburetors vary 伊 eatly in construction, but they alI operate 伽 sa me w:ay. The ir jo

45、 b is to supply the co汀ect mixture of 肛 I and.air to the 中 gine in response to varyjog conditions.P血 cipal sub-assembliesO:n m偽 t ca巾叩 tor mQdels include a 切wl c Qvi，吐 rbure tody , A thick gasket betw心 o the throttle body and main body retards ihea t 廿 an sferto the fuel tn order to help 比 sist fuel

46、 percolation in warm weather. To correctly identify the carb 叩 tor model, always ch.eek the part num 比 r stamped on the main 切 dy or attached tag. The carburetor includ 邸 four basic fuel metering systems. The idle system provid 邸 a mixture for smocth 心 e and a 血 nsfer system for low speed operation.

47、 Tbe main metering system provides 扭economical mixtu 兀 for normal Cruisiog conditions (and a fuel regulator i-.0leno id/vacu um modulator on feedback systems) 九e accelerator system provides.additional fue如 ring accelera tion 九e power9(:pri;hm en t system provides a richer mixture when high power out

48、put is desired.AlrlilterKeyA”FuelWordsFig. 1,8 C田away vi妞 ofa carbur你orfiltern. 濾消器，過(guò)濾器metering n 測(cè)量，計(jì)縣，記錄 carburetorn. 化油器，汽化器in陀 tionn. 注入，注M, 噴射gaugen 規(guī) 表，計(jì)semdingn. 發(fā)送mesh11. 網(wǎng)孔，網(wǎng)絲，網(wǎng)眼，圈套，喳合screenn. 濾網(wǎng)adventn.（尤指不尋常的人或事）出現(xiàn)到來(lái)ventn. 通風(fēng)孔，出口 ，通路activatedadj. 有活性的笠 rb-0.nn. 碳，碳素ch11rcoaln. 木炭，活性炭，炭啦 i

49、stern. 睹，金屬罐，金屬容器，濾Notes哥磕float bowl浮子室ecceptricadj. 偏心的，不同心的n.偏心輪，偏心器flexibleadj. 撓曲的，可曲的，柔性的， 韌性的，可彎曲的diaph ra即ln. 薄膜，膜片che-ck valven. 單向閥，止回閥vanen. 覽，葉片，風(fēng)標(biāo)distributora. 分電器，配電器impellern. 葉輪，轉(zhuǎn)輪，槳 葉bellow$n，波紋管，波形膜，風(fēng)箱electromagn.etn. 電磁鐵de-.ene屯口en 斷電，斷開(kāi)，關(guān)斷impeller驅(qū)動(dòng)葉輪：用做離心泵的旋轉(zhuǎn)元件，將機(jī)掖能貴轉(zhuǎn)化為流體能量。Exerc

50、isesWhat are the main pa心 of the fuel delive可 system?10How does the moch血 cal pwnp operate?What血 dsof :fiIt燈 S毗 出ere in出e engines?How many typ,es of feedback carburetors are there in automotive engines?Reading MaterialFuel Injection SystemsIn訂oductionFuel injection sy 啦 ms (As shown in Pig. 1-9) hav

51、e been u,sed on ve hicles for many years., The earliest ones were p叩 ly m心 hanicaL As 氐 hnology advan咄 electronic fuel injection s ys比m 比came m()re popular. E江 ly tt1心 h缸 ical 血 d electrc,n.ic: fueE i nje c tion systems did not use feedback con 汀 ols. As emissions bee 血 e mo,re of a co n 位 m, f 氏 db

52、ack 心 ntrols were adapted to 皿 叩 es of fuel injeict i,o n systems. Both mec 厄 nical and el 虹 tronic fuel injection sys 邸 邱 can be fo 皿 d ongasoline engines.白 es 迎 e re 配 letor向吐tor-令Mand0日口終生”匡三Fig, 19 F 歸 I injection 5ystemMulti-port fuel inj沈 tionsThis :is 山 e mo s t common type of fuel injectioo

53、system found today (As shown in Fig. 1-10). Regardle.ss of the manufactu-rer, they all fumction in the same b的 c way.Om小ese systems 扭 equalamount of fuel is delivered to each cylmi der.The5e systems all use sensors which transmit operating conditions tohe computer. Information from these se.n-sors i

54、s pro cesse d by the compwter which then determines the pm 產(chǎn)忒 r/fuel mix. 血 e. This signal is sent ihe to fuel injectors whtch open and iaj 吐 fuel into their ports. The longer 小 e injector is held open, the richer the 和 el mixt舊M心 t fuel injection sys比ms ne” 由e followmg inf0皿 的 Oll to ope戊 te proper

55、ly:LL為 g.I-!0 Bosch.fuel s;uppUy sys如l一 和cl tan,k 一 缸 Ip血 p 3氣 如 filter 4勹 亞 e re產(chǎn) I O.r 5 -, 芯 S ure如 畛6-oootrol uni ,仁 初 還 on如 ，In，叩一的如m valr 切 Id!血 1 vol,e JO,- 讓 rottle劉 ve ll - IUO廳levalvt 心1-2, a i 氐 m m 歸13 -c) 噴 婦 沁叩14一 如 m .ti me僅 1心15-t 叩 丙 a 應(yīng) ” cn.sorI仁, uxilimmr妞 Ive J?- 際,acem址 江 ruor

56、IS-m ain飛 lay I已 Mm p心 yT emp e ra血 e senso:rs-this includes iboth a:ir 血 d coolant temperature. The computer uses this info血 ation to determine how rich or lean 中e mixtu尺 sh.ould 加，The 沁 Ider the iemperature, 如:richer themixtureThrottle沁 itfon sensors or switche亡 the compu比r uses this imntormation

57、to detem血 e tlie嚴(yán) lion of the 如 ottle valve(s). Some vehicles use sensors which rell:ry th.e exact position of the 加 :ottle valwe(s)1! 1111 times. Others use swi比hes which. only relay closed and wid 叩切 如 ottle嚴(yán) l令 0ns (so me 血 y also u沈 a 而d-tbrottle switch), Thes.e switches and sensors help dete血 i

58、 ne engine load.心幣ow sen ors-thesesensors also help th.e computer le te 叩 ine engin,e load by indi cat i rng如 叩 0 皿 t of airente血 g the engine. There are several different types ofairflow sel!lsors, butin the end; they all do 如 same job/2M 血 fold pr 岱 sure sensors-if a vehicle is not equipped with a

59、o airflow sensor, it uses amanifold pre達(dá) ure sensor to determine engine load (Note that llome vehicles with an airflow sensor may also have a manifold pressure sensor. This is used!as a fail-sa fe if the air伍ow sensor fails). As engine load increases, so d沁 s intake manifold air pressure.Eng1t1e s p

60、e心d 的 d 尸ition 玩 Ii沁 飛一 eng加 spee心positiOiI S lSQ氏 也 n be referenced丘om the era 咄 shaft, c 皿 shaft or both. lil. addition to helping determine en.gine !Qad,， 由 ESE 托 叩 rs also tell the-computer when lhe mjectors.should 比 fired.These systems operate at a relatively hi的 pressure (usually at least 30 p