1、汽車專業(yè)英語(yǔ)汽車專業(yè)英語(yǔ) Specialty English for Automobile劉永剛劉永剛E-mail: Tel:hapter 2 Internal combustion engine 2.1 Principle of Operation Energy Power Chemical energy Burn / combustion Combustion chamber Internal (external) combustion engine Cylinder Heat engine Mechanical pistonInlet valvepistonco

2、nnecting rodTDCBDCExhaust valvecrankEngine TermsTDC（Top Dead Center）: the position of the crank and piston when the piston is farthest away from the crankshaft.BDC（Bottom Dead Center）: the position of the crank and piston when the piston is nearest away from the crankshaft.2.1.2 Engine terms 缸徑缸徑bor

3、estrokeTDCBDCClearancevolumeSweptvolumeClearance volume（余隙余隙/燃燒室容積）燃燒室容積）: : the volume of space above the piston when it is at TDC.Engine capacity（排量）（排量）: : this is the swept volume of all cylinders.Compression ratio（壓縮比）（壓縮比）: :(swept vol + clearance vol) /(clearance vol)活塞活塞行程行程Swept volume（有效（有

4、效/ /工工作容積）作容積）: :the volume between TDC and BDC.TDCBDCStrokeBoreSwept volumeEngine capacityClearance volumeCompression ratio Two-stroke: a power stroke every revolution of the crank Four-stroke: a power stroke every other revolution of the crank 每隔一個(gè)每隔一個(gè) Top Dead Center Bottom Dead Center Stroke Bor

5、e Swept volume Engine capacity Clearance volume Compression ratio Two-stroke/Four-stroke revolution2.1.3 The four-stroke spark-ignition engine cycle1. Intake/Induction stroke 進(jìn)氣行程進(jìn)氣行程2. Compression stroke 壓縮行程壓縮行程3. Power stroke 作功行程作功行程4. Exhaust stroke 排氣行程排氣行程ward(s) 后綴后綴 表示方向表示方向2.1.4 Engine ove

6、rall mechanics Crankshaft and Connecting rods system 曲柄連桿機(jī)構(gòu)曲柄連桿機(jī)構(gòu) Valve system 配氣機(jī)構(gòu)配氣機(jī)構(gòu) Fuel system 供給系供給系 Intake system 進(jìn)氣系統(tǒng)進(jìn)氣系統(tǒng) Cooling system 冷卻系冷卻系 Ignition system 點(diǎn)火系點(diǎn)火系 Starting system 起動(dòng)系起動(dòng)系 Lubrication system 潤(rùn)滑系潤(rùn)滑系 Exhaust system 排氣系統(tǒng)排氣系統(tǒng)2.2 Engine block and cylinder head發(fā)動(dòng)機(jī)缸體是發(fā)動(dòng)機(jī)的基本骨架，發(fā)動(dòng)機(jī)其

7、余的零件或安裝發(fā)動(dòng)機(jī)缸體是發(fā)動(dòng)機(jī)的基本骨架，發(fā)動(dòng)機(jī)其余的零件或安裝在缸體內(nèi)部，或固定在缸體上。缸體里有氣缸、水套和油道，在缸體內(nèi)部，或固定在缸體上。缸體里有氣缸、水套和油道，曲軸也固定在缸體底部。除了頂置凸輪軸發(fā)動(dòng)機(jī)以外，凸輪曲軸也固定在缸體底部。除了頂置凸輪軸發(fā)動(dòng)機(jī)以外，凸輪軸都固定在缸體內(nèi)部。大多數(shù)汽車上，缸體采用灰鑄鐵或者軸都固定在缸體內(nèi)部。大多數(shù)汽車上，缸體采用灰鑄鐵或者灰鑄鐵和其他金屬（例如鎳或鉻）的合金鑄造而成。灰鑄鐵和其他金屬（例如鎳或鉻）的合金鑄造而成。The engine block is the basic frame of the engine. All other en

8、gine parts either fit inside it or fasten to it. It holds the cylinders, water jackets, and oil galleries. The engine block also holds the crankshaft, which fastens to the bottom of the block. The camshaft also fits inside the block, except on overhead-cam engines (OHC). In most cars, this block is

9、made of gray iron, or an alloy (mixture) of gray iron and other metals, such as nickel or chromium. Engine blocks are castings.Be made of / manufactured withWear：穿戴，磨損：穿戴，磨損Line with: 布滿；布滿；給給加加The path to the house is lined with bushes.通向那所房子的小徑長(zhǎng)滿了灌木叢。通向那所房子的小徑長(zhǎng)滿了灌木叢。The coat is lined with silk.這件外

10、套用綢子作襯里。這件外套用綢子作襯里。Cylinder sleeves 氣缸套氣缸套Cylinder sleeves are used in engine blocks to provide a hard wearing material for pistons and piston rings. The block can be made of one kind of iron that is light and easy to cast while the sleeves uses another that is better able to stand up wear and tear.

11、 There are two main types of sleeves: dry and wet. 發(fā)動(dòng)機(jī)缸體中的氣缸套為活塞和活塞環(huán)提供一種堅(jiān)發(fā)動(dòng)機(jī)缸體中的氣缸套為活塞和活塞環(huán)提供一種堅(jiān)硬耐磨的材料。缸體可以采用較輕且易鑄造的鐵，硬耐磨的材料。缸體可以采用較輕且易鑄造的鐵，而氣缸套采用更耐磨和耐沖擊的材料。氣缸套分為而氣缸套采用更耐磨和耐沖擊的材料。氣缸套分為兩種：干式和濕式。兩種：干式和濕式。2.2.2 Cylinder sleeves2.2.3 Cylinder headThe cylinder head fastens to the top of the block, just as

12、 a roof fits over a house. The underside forms the combustion chamber with the top of the piston. In-line engines of light vehicles have just one cylinder head for all cylinders; larger in-line engines can have two or more. 氣缸蓋固定在氣缸體的頂部，就像房子的房頂一樣。氣缸蓋固定在氣缸體的頂部，就像房子的房頂一樣。氣缸蓋底部與活塞頭部之間的空間形成了燃燒室。氣缸蓋底部與活塞

13、頭部之間的空間形成了燃燒室。輕型汽車的直列式發(fā)動(dòng)機(jī)采用一個(gè)氣缸蓋，較大的輕型汽車的直列式發(fā)動(dòng)機(jī)采用一個(gè)氣缸蓋，較大的直列式發(fā)動(dòng)機(jī)采用兩個(gè)或多個(gè)氣缸蓋。直列式發(fā)動(dòng)機(jī)采用兩個(gè)或多個(gè)氣缸蓋。in-line 直列式直列式V型型Hemi 半球形半球形Wedge 楔形楔形Basin 盆形盆形Flat enginePancake engine 對(duì)置式對(duì)置式arrangementCylinder headIn-line enginePetrol 英英gasoline 美美Combustion chamberGasketSandwichAsbestos 石棉石棉Copper 銅銅Oil pan or sump

14、油底殼油底殼 / 集油槽集油槽 油底殼油底殼Oil panCrankcaseOil pumpLubricating systemCirculationThe oil pump in the lubricating system draws oil from the oil pan and sends it to all working parts in the engine. The oil drains off and runs down into the pan. Thus, there is constant circulation of oil between the pan and

15、the working pats of the engine. 潤(rùn)滑系的機(jī)油泵從油底殼抽出機(jī)油潤(rùn)滑系的機(jī)油泵從油底殼抽出機(jī)油，并把機(jī)油輸送給發(fā)動(dòng)機(jī)的所有工，并把機(jī)油輸送給發(fā)動(dòng)機(jī)的所有工作部件。機(jī)油從油底殼流進(jìn)流出。作部件。機(jī)油從油底殼流進(jìn)流出。因而在油底殼和發(fā)動(dòng)機(jī)的工作部件因而在油底殼和發(fā)動(dòng)機(jī)的工作部件之間就有機(jī)油定向循環(huán)流動(dòng)。之間就有機(jī)油定向循環(huán)流動(dòng)。Oil Pan / Sump 油底殼油底殼Oil PanComponents of a typical, four stroke cycle, D(dual)OHC piston engine. (E) Exhaust camshaft,(I)

16、 Intake camshaft, (S) Spark plug, (V) Valves, (P) Piston, (R) Connecting rod, (C) Crankshaft,(W) Water jacket for coolant flow.cylinder headhead coverwater jacketoil galleryoil pangasketcylindercylinder sleeveengine blockcrankcaseEngine block and Cylinder head 曲軸箱曲軸箱氣缸蓋罩氣缸蓋罩氣缸氣缸氣缸套氣缸套氣缸體氣缸體油底殼油底殼氣缸蓋

17、氣缸蓋襯墊襯墊水套水套油道油道Crankshaft 曲軸曲軸Piston ring 活塞環(huán)活塞環(huán)Piston (crownskirt)活塞（頭部裙部）活塞（頭部裙部）Piston pin活塞銷活塞銷Connecting rod連連 桿桿Big-end 連桿大頭連桿大頭Small-end 連桿小頭連桿小頭Cap 連桿蓋連桿蓋Shell bearing軸軸 瓦瓦M(jìn)ain bearing journal主軸頸主軸頸Connecting rod journal 連桿軸徑連桿軸徑Flywheel 飛輪飛輪2.3 Piston, Connecting rod and CrankshaftThe pisto

18、n is an important part of a four-stroke cycle engine. Most pistons are made from cast aluminum. The piston, through the connecting rod, transfers to the crankshaft the force created by the burning fuel mixture. This force turns the crankshaft. Thin, circular, steel bands fit into grooves around pist

19、on to seal the bottom of the combustion chamber. These bands are called piston rings. The grooves into which they fit are called ring grooves. A piston pin fits into a round hole in the piston. The piston pin joins the piston to the connecting rod. The thick part of the piston that holds the piston

20、pin is the pin boss.大多數(shù)活塞由鋁鑄造而成。通過(guò)連桿大多數(shù)活塞由鋁鑄造而成。通過(guò)連桿的作用，活塞把可燃混合氣燃燒產(chǎn)生的作用，活塞把可燃混合氣燃燒產(chǎn)生的力傳遞給曲軸，帶動(dòng)曲軸旋轉(zhuǎn)。的力傳遞給曲軸，帶動(dòng)曲軸旋轉(zhuǎn)。Piston AssemblyFlatConcaveDomeRecessedIn diesel engines, the combustion chamber may be formed totally or in part in the piston crown, depending on method of injection. 柴油機(jī)發(fā)動(dòng)機(jī)根據(jù)噴柴油機(jī)發(fā)動(dòng)機(jī)根據(jù)噴

21、油方法不同，活塞頭油方法不同，活塞頭部可以形成全部燃燒部可以形成全部燃燒室，也可以是燃燒室室，也可以是燃燒室的一部分的一部分PistonCompression ring: 氣環(huán)氣環(huán) 壓縮環(huán)壓縮環(huán) 壓環(huán)壓環(huán)Oil ring： 油環(huán)油環(huán)Piston ringsGas RingsOil RingsThe connecting rod is made of forged high-strength steel. It transmits force and motion from the piston to the crankpin on the crankshaft. The connecting

22、rod little end is connected to the piston pin. A bush made from a soft metal, such as bronze, is used for this joint. The lower end of the connecting rod fit the crankshaft journal. This is called the big end. 連桿采用高強(qiáng)度鍛造鋼。連桿將活塞的力連桿采用高強(qiáng)度鍛造鋼。連桿將活塞的力和運(yùn)動(dòng)傳遞給曲軸上的曲柄銷。連桿小頭和運(yùn)動(dòng)傳遞給曲軸上的曲柄銷。連桿小頭與活塞銷連接，連接處有像與活塞銷連接

23、，連接處有像青銅青銅這樣軟金這樣軟金屬制成的屬制成的襯套襯套，連桿下端連接在，連桿下端連接在曲柄軸徑曲柄軸徑上，稱為連桿大頭。上，稱為連桿大頭。2.3.3 connecting rodThe piston is an important part of a four-stroke cycle engine. Most pistons are made from cast aluminum. The piston, through the connecting rod, transfers to the crankshaft the force created by the burning fu

24、el mixture. This force turns the crankshaft. Thin, circular, steel bands fit into grooves around piston to seal the bottom of the combustion chamber. These bands are called piston rings. The grooves into which they fit are called ring grooves. A piston pin fits into a round hole in the piston. The p

25、iston pin joins the piston to the connecting rod. The thick part of the piston that holds the piston pin is the pin boss.2.3.4 crankshaftConjunction: 連接，同時(shí)發(fā)生連接，同時(shí)發(fā)生a conjunction of favourable political and economic circumstancesIn conjunction with：和：和一起一起Reciprocating: 往復(fù)往復(fù)bearing journal: 軸頸軸頸Alloy

26、: n/vt 合金，合金，mix (metals) to make an alloythrow：半徑，行程：半徑，行程TDC、BDC、Vice versa2.3.5 cylinder numbering and firing orderImpluse/pulse 脈沖脈沖Flow 流程流程Space ：把：把.分隔開(kāi)分隔開(kāi), 排開(kāi)排開(kāi), 按一定距離安排開(kāi)按一定距離安排開(kāi) space out the lampposts 30 meters apartInterval 間隔間隔Diagram: 簡(jiǎn)圖，示意圖簡(jiǎn)圖，示意圖Firing order: 點(diǎn)火順序點(diǎn)火順序2.5 Valve systemTh

27、e valve system is made up of those parts needed to open and close the valves at just the right time.To coordinate the four-stroke cycle, a group of parts called the valve trains opens and closed the valves (moves them down and up, respectively). These valve movements must take place at exactly the r

28、ight moments. The opening of each valve is controlled by a camshaft.The cam is an egg-shaped piece of metal on a shaft that rotates in coordination with the crankshaft. The metal shaft, called the camshaft, typically has individual cams for each valve in the engine. As the camshaft rotates, the lobe

29、, or high spot of the cam, pushes against parts connected to the stem of the valve. This action forces the valve to move downward. This action could open an inlet valve for an intake stroke, or open an exhaust valve for an exhaust stroke.凸輪是一個(gè)蛋形的金屬塊，它安裝在同曲凸輪是一個(gè)蛋形的金屬塊，它安裝在同曲軸協(xié)調(diào)運(yùn)轉(zhuǎn)的一根金屬軸上，該軸稱為凸軸協(xié)調(diào)運(yùn)轉(zhuǎn)的一根

30、金屬軸上，該軸稱為凸輪軸，其上有同發(fā)動(dòng)機(jī)每一個(gè)氣門(mén)對(duì)應(yīng)的輪軸，其上有同發(fā)動(dòng)機(jī)每一個(gè)氣門(mén)對(duì)應(yīng)的凸輪。當(dāng)凸輪軸旋轉(zhuǎn)時(shí)，凸輪的最高點(diǎn)，凸輪。當(dāng)凸輪軸旋轉(zhuǎn)時(shí)，凸輪的最高點(diǎn)，也就是凸圓，推動(dòng)連接氣門(mén)桿的部件，使也就是凸圓，推動(dòng)連接氣門(mén)桿的部件，使得氣門(mén)向下運(yùn)動(dòng)，在進(jìn)氣沖程打開(kāi)進(jìn)氣門(mén)得氣門(mén)向下運(yùn)動(dòng)，在進(jìn)氣沖程打開(kāi)進(jìn)氣門(mén)，在排氣沖程打開(kāi)排氣門(mén)。，在排氣沖程打開(kāi)排氣門(mén)。Valves in modern car engines are located in the cylinder head at the top of the engine. This is known as an overhead valve

31、 (OHV) configuration. In addition, when the camshaft is located over the cylinder head, the arrangement is known as an overhead camshaft (OHC) design. Some high performance engines have two separate camshafts, one for each set of inlet and exhaust valves. These engines are known as dual overhead-cam

32、shaft (DOHC) engine.In this arrangement, the cam lobes push against round metal cylinders called cam follower. As the lobe of the cam comes up under the cam follower, it pushes the cam follower upward (away from the camshaft). The cam follower rides against a push rod, which pushes against a rocker

33、arm. The rocker arm pivots on a shaft through its center. As one side of the rocker arm moves up, the other side moves down, just like a seesaw. The downward-moving side of the rocker arm pushes on the valve stem to open the valve.Push-rod valve trainRocker-arm（搖臂）（搖臂）CamshaftTappet(Cam follower)Pus

34、h-rodValve clearancesValve SpringValve stemValve seat（氣門(mén)座）（氣門(mén)座）Valve headPistonRocker-shaft2.5.2 Valve clearanceWhen the engine runs in compression stroke and power stroke, the valves must close tightly on their seats to produce a gas-tight seal and thus prevent the gases escaping from the combustio

35、n chamber. If the valves do not close fully the engine will not develop full power. Also the valve heads will be liable to be burnt by the passing hot gases, and there is the likelihood of the piston crown touching an open valve, which can seriously damage the engine.當(dāng)發(fā)動(dòng)機(jī)處于壓縮行程或做功行程時(shí)，氣門(mén)必須緊閉在氣門(mén)座當(dāng)發(fā)動(dòng)機(jī)處

36、于壓縮行程或做功行程時(shí)，氣門(mén)必須緊閉在氣門(mén)座上，提供很好的密封性，從而防止氣體從燃燒室中溢出。如果上，提供很好的密封性，從而防止氣體從燃燒室中溢出。如果氣門(mén)不能完全關(guān)閉，則發(fā)動(dòng)機(jī)不能產(chǎn)生最大的功率。另外氣門(mén)氣門(mén)不能完全關(guān)閉，則發(fā)動(dòng)機(jī)不能產(chǎn)生最大的功率。另外氣門(mén)頭容易被流經(jīng)的高溫氣體燒蝕，有可能導(dǎo)致活塞頭部沖擊打開(kāi)頭容易被流經(jīng)的高溫氣體燒蝕，有可能導(dǎo)致活塞頭部沖擊打開(kāi)的氣門(mén)，會(huì)嚴(yán)重破壞發(fā)動(dòng)機(jī)。的氣門(mén)，會(huì)嚴(yán)重破壞發(fā)動(dòng)機(jī)。為保證氣門(mén)能完全關(guān)閉，必須在氣門(mén)工作機(jī)為保證氣門(mén)能完全關(guān)閉，必須在氣門(mén)工作機(jī)構(gòu)中留有間隙。這就意味著氣門(mén)傳動(dòng)機(jī)構(gòu)和構(gòu)中留有間隙。這就意味著氣門(mén)傳動(dòng)機(jī)構(gòu)和氣門(mén)之間有足夠遠(yuǎn)的距離，從而

37、保證氣門(mén)能氣門(mén)之間有足夠遠(yuǎn)的距離，從而保證氣門(mén)能夠在彈簧的作用下緊閉氣門(mén)座。但是如果氣夠在彈簧的作用下緊閉氣門(mén)座。但是如果氣門(mén)間隙過(guò)大，會(huì)產(chǎn)生輕微的金屬敲打聲。門(mén)間隙過(guò)大，會(huì)產(chǎn)生輕微的金屬敲打聲。So that the valves can close fully some clearance is needed in the operating mechanism. This means that the operating mechanism must be able to move sufficiently far enough away from the valve to allow

38、the valves to be fully closed against its seat by the valve spring. However, if the clearance is set too great this will cause a light metallic tapping noise. 2.5.3 valve timingThe time at which valves open and close (valve timing) and duration of valve opening is stated in degrees of crankshaft rot

39、ation. For example, the intake valve normally begins to open just before the piston has reached top dead center. The valve remains open as the piston travels down to BDC and even past BDC. This is intake valve duration. An example of this could be stated as follows: IO at 17oBTDC, IC at 51oABDC (or,

40、 intake opens 17obefore top dead center, intake closes 51o after bottom dead center). Intake valve duration in this case is 248o of crankshaft rotation.It is apparent from this description that the exhaust valve stays open for a short period of time during which the intake valve is also open. In oth

41、er words, the end of the exhaust stroke and the beginning of the intake stoke overlap for a short period of time. This is called valve overlap. Valve timing and valve overlap vary on different engines. 從上述描述顯而易見(jiàn)，排氣門(mén)開(kāi)啟時(shí)，有一小段時(shí)間，進(jìn)氣門(mén)也從上述描述顯而易見(jiàn)，排氣門(mén)開(kāi)啟時(shí)，有一小段時(shí)間，進(jìn)氣門(mén)也是開(kāi)啟的。換句話說(shuō)，排氣行程終了和進(jìn)氣行程初期有一短時(shí)間是開(kāi)啟的。換句話說(shuō)，排氣行程

42、終了和進(jìn)氣行程初期有一短時(shí)間的重疊，這就稱之為氣門(mén)重疊。不同的發(fā)動(dòng)機(jī)具有不同的氣門(mén)正的重疊，這就稱之為氣門(mén)重疊。不同的發(fā)動(dòng)機(jī)具有不同的氣門(mén)正時(shí)和氣門(mén)重疊。時(shí)和氣門(mén)重疊。The entire valve-train assembly can be viewed as a spring/mass system in which the conversion from stored to free energy causes forced vibration. Valve-train assemblies with overhead camshafts can be represented with

43、 sufficient accuracy by a 1-mass system ( (consisting of the moving mass, the valve-train assembly stiffness and corresponding damping) ). 整個(gè)氣門(mén)傳動(dòng)機(jī)構(gòu)可以被看做成一個(gè)彈簧整個(gè)氣門(mén)傳動(dòng)機(jī)構(gòu)可以被看做成一個(gè)彈簧/ /質(zhì)量系統(tǒng)，其儲(chǔ)質(zhì)量系統(tǒng)，其儲(chǔ)存的能量轉(zhuǎn)換為自由能量時(shí)產(chǎn)生了受迫振動(dòng)。頂置凸輪軸存的能量轉(zhuǎn)換為自由能量時(shí)產(chǎn)生了受迫振動(dòng)。頂置凸輪軸的氣門(mén)傳動(dòng)總成可非常精確地用單質(zhì)量系統(tǒng)（包含移動(dòng)的的氣門(mén)傳動(dòng)總成可非常精確地用單質(zhì)量系統(tǒng)（包含移動(dòng)的質(zhì)量、氣門(mén)機(jī)構(gòu)總

44、成的剛度和相應(yīng)的阻尼）表示。質(zhì)量、氣門(mén)機(jī)構(gòu)總成的剛度和相應(yīng)的阻尼）表示。2.5.4 cam design and control dynamics2.5.5 camshaft drive mechanismEach cam must revolve once during the four-stroke cycle to open a valve. A cycle, remember, corresponds with two revolutions of the crankshaft. Therefore, the camshaft must revolve at exactly haft

45、the speed of the crankshaft. This is accomplished with a 2:1 gear ratio. A gear connected to the camshaft has twice the number of teeth as a gear connected to the crankshaft.Belt driveCog-type belt 齒形帶齒形帶Reinforce：加強(qiáng)：加強(qiáng)Fiberglass：玻璃纖維：玻璃纖維Slotted：開(kāi)槽：開(kāi)槽Chain driveGear driveVariable valve timing In in

46、ternal combustion engines, variable valve timing, often abbreviated to VVT, is a generic term for an automobile piston engine technology. VVT allows the lift, duration or timing (in various combinations) of the intake and/or exhaust valves to be changed while the engine is in operation.The profile,

47、or position and shape of the cam lobes on the shaft, is optimized for a certain engine revolutions per minute (RPM), and this tradeoff normally limits low-end torque, or high-end power. VVT allows the cam timing to change, which results in greater efficiency and power, over a wider rev-range.通用、專業(yè)術(shù)語(yǔ)

48、；輪廓、型線；轉(zhuǎn)速通用、專業(yè)術(shù)語(yǔ)；輪廓、型線；轉(zhuǎn)速/分；分；低端扭矩；高端功率低端扭矩；高端功率At high engine speeds, an engine requires large amounts of air. However, the intake valves may close before all the air has been given a chance to flow in, reducing performance. On the other hand, if the cam keeps the valves open for longer periods of

49、time, as with a racing cam, problems start to occur at the lower engine speeds. This will cause unburnt fuel to exit the engine since the valves are still open. This leads to lower engine performance and increased emissions. For this reason, pure racing engines cannot idle at the low speeds (around

50、800rpm) expected of a road car, and idle speeds of 2000 rpm are not unusual.Pressure to meet environmental goals and fuel efficiency standards is forcing car manufacturers to turn to VVT as a solution. Most simple VVT systems advance or retard the timing of the intake or exhaust valves. Others (like

51、 Hondas VTEC) switch between two sets of cam lobes at a certain engine RPM. Furthermore Hondas I-VTEC can alter intake valve timing continuously.VTEC (Variable Valve Timing and Lift electronic Control) 可變氣門(mén)配氣相位和氣門(mén)升程電子可變氣門(mén)配氣相位和氣門(mén)升程電子控制系統(tǒng)控制系統(tǒng) is a valvetrain system developed by Honda to improve the vo

52、lumetric efficiency of a four-stroke internal combustion engine. This system uses two camshaft profiles and electronically selects between the profiles. It was invented by Honda R&D engineer Ikuo Kajitani. VTEC was the first system of its kind, though other variable valve timing and lift control sys

53、tems have been produced by other manufacturers (MIVEC from Mitsubishi, VVTL-i from Toyota, VarioCam Plus from Porsche, VVL from Nissan, etc)VVT-i, or Variable Valve Timing with intelligence, is an automobile variable valve timing technology developed by Toyota, similar in performance to the BMWs VAN

54、OS.生詞表生詞表EngineStoke：inductionCompressionpoweremissionTop/bottom dead centerSwept volumeCompression ratioClearance volumeEngine capacityMechanicsMechanism meknizmBlockWater jacketCylinder sleeve (dry or wet)Cylinder headCombustion chamberGasketOil pan sumpPiston /- ring /- pinConnecting rodCrankshaf

55、tBearing journalReciprocateFiring orderFlywheelPiston crown / skirtDiagram 生詞表生詞表mountingAmplitudeRollPitchyawValve systemCamshaftOverheadHead Camshaft valve trainPush-rod valve trainCam followerPush rodRocker armValve seatValve clearanceValve timingIntake/ exhaust valveBelt / chain / gearTeeth (gea

56、r)Today, internal combustion engines in cars, trucks, motorcycles, aircraft, construction machinery and many others, most commonly use a four-stroke cycle. The four strokes refer to intake, compression, combustion (power), and exhaust strokes that occur during two crankshaft rotations per working cy

57、cle of the gasoline engine and diesel engine.The cycle begins at top dead center (TDC), when the piston is farthest away from the axis of the crankshaft. On the intake or induction stroke of the piston, the piston descends from the top of the cylinder, reducing the pressure inside the cylinder. A mi

58、xture of fuel and air is forced (by atmospheric or greater pressure) into the cylinder through the intake (inlet) port. The intake (inlet) valve (or valves) then close(s), and the compression stroke compresses the fuelair mixture.The airfuel mixture is then ignited near the end of the compression st

59、roke, usually by a spark plug (for a gasoline or Otto cycle engine) or by the heat and pressure of compression (for a Diesel cycle or compression ignition engine). The resulting pressure of burning gases pushes the piston through the power stroke. In the exhaust stroke, the piston pushes the product

60、s of combustion from the cylinder through an exhaust valve or valves. 汽車的動(dòng)力源是發(fā)動(dòng)機(jī)。發(fā)動(dòng)機(jī)乃是將某一種形式的汽車的動(dòng)力源是發(fā)動(dòng)機(jī)。發(fā)動(dòng)機(jī)乃是將某一種形式的能量轉(zhuǎn)變?yōu)闄C(jī)械能的機(jī)器。將熱能轉(zhuǎn)變?yōu)闄C(jī)械能的發(fā)動(dòng)能量轉(zhuǎn)變?yōu)闄C(jī)械能的機(jī)器。將熱能轉(zhuǎn)變?yōu)闄C(jī)械能的發(fā)動(dòng)機(jī)，稱之為熱力發(fā)動(dòng)機(jī)，其中的熱能是由燃料燃燒所產(chǎn)機(jī)，稱之為熱力發(fā)動(dòng)機(jī)，其中的熱能是由燃料燃燒所產(chǎn)生的。內(nèi)燃機(jī)是熱力發(fā)動(dòng)機(jī)的一種，其特點(diǎn)是液體或氣生的。內(nèi)燃機(jī)是熱力發(fā)動(dòng)機(jī)的一種，其特點(diǎn)是液體或氣體燃料和空氣混合后直接輸入機(jī)器內(nèi)部燃燒而產(chǎn)生熱能，體燃料和空氣混合后直接輸入機(jī)器