發(fā)動機冷卻系統(tǒng)外文翻譯

1、<p><b>　　英文翻譯：</b></p><p><b>　　原文：</b></p><p>　　The Cooling System</p><p>　　The engine cooling system actually is a temperature regulation system to

2、protect engine from self-destruction. About one-third of the heat produced in the engine is converted into power, another third goes out through the exhaust pipe un-used, and the remaining third must be carried away by

3、the cooling system (Some is utilized for heating the passenger compartment). To keep the engine temperature in balance is quite essential for an engine to produce power. If the engine runs too hot, it may su</p>&

4、lt;p>　　There are two types of cooling systems found on motor vehicles: liquid cooled and air cooled .Air cooled engines are found on a few older cars, like the original Volkswagen Beetle, the Chevrolet Corsair and a f

5、ew others. Many modern motorcycles still use air cooling, but for the most part, automobiles and trucks use liquid cooled systems and that is what this article will concentrate on.</p><p>　　Components of a l

6、iquid cooling system include the radiator, radiator cooling fans and fan drive belt, pressure cap & reserve tank, water pump, thermostat, bypass system, freeze plugs, head gaskets & intake manifold gaskets, heate

7、r core and hoses. In detail, the cooling system is made up of the passages ( water jacket) inside the engine block and heads, a water pump to circulate the coolant, a thermostat to control the temperature of the coolant,

8、 a radiator to cool the coolant, a radiator cap to </p><p>　　A liquid cooling system works by sending a liquid coolant through passages in the engine block and heads. As the coolant (low freezing liquid call

9、ed antifreeze) flows through these passages, it picks up heat from the engine. The heated fluid then makes its way through a rubber hose to the radiator in the front of the car. As it flows through the thin tubes in the

10、radiator, the hot liquid is cooled by the air stream entering the engine compartment from the grill in front of the car. Once the flu</p><p>　　A thermostat is placed between the engine and the radiator to m

11、ake sure that the coolant stays above a certain preset temperature. If the coolant temperature falls below this temperature, the thermostat blocks the coolant flow to the radiator, forcing the fluid instead through a byp

12、ass directly back to the engine. The coolant will continue to circulate like this until it reaches the design temperature, at which point, the thermostat will open a valve and allow the coolant back through the radiat<

13、;/p><p>　　V-type engines have a pump on each cylinder block.</p><p>　　Radiator is a device designed to dissipate the heat, which the coolant has absorbed from the engine; it is constructed to hold

14、a large amount of water in tubes or other passages, which provide a large area in contact with the atmosphere. Radiator cores are of two basic types, the fin and tube type (fins are placed around the tube to increase the

15、 area for radiating the heat) and of the ribbon cellular or honey comb type.</p><p>　　For a late-model engine, the cooling system must maintain a temperature that is high enough for efficient combustion but

16、not so high that the engine will be damaged. These requirements are very critical for an engine with electronic controls that must maintain precise air-fuel ratios for fuel econo-my and emission control.</p><p

17、>　　Transmission oil cooler</p><p>　　Automatic transmission oil is cooled by a small, separate radiator, usually located in the lower tank or alongside the main radiator. While the only purpose of the engi

18、ne coolant is to keep the block and upper engine components cool, the transmission oil has three functions. It hydraulically</p><p>　　operates the transmission, lubricates the transmission internal and also

19、keeps the transmission within proper operating temperature range.</p><p>　　Most vehicles can benefit from the installation of transmission oil cooler, especially if the vehicle is used to pull a trailer or f

20、or some other kind of heavy service.</p><p>　　Engine oil cooler</p><p>　　Some vehicles, particularly high performance or diesel engines, are equipped with engine oil cooler. The oil cooler can b

21、e located in one of the radiator tanks (similar to the transmission oil cooler), or mounted separately, near the front of the engine, on aftermarket applications. Also there is usually an adapter mounted between the engi

22、ne block and the oil filter. If the cooler is mounted in a radiator tank, heat is dispersed from the oil to the coolant. A separate oil cooler usually looks li</p><p><b>　　譯文：</b></p><

23、p><b>　　冷卻系統(tǒng)</b></p><p>　　發(fā)動機冷卻系統(tǒng)實際上是一個溫度調(diào)節(jié)系統(tǒng)，以保護發(fā)動機不會因為過熱損壞。發(fā)動機產(chǎn)生的熱量大約有三分之一轉(zhuǎn)化成動力，另外三分之一沒有使用，通過排氣管散發(fā)出去，其余的三分之一由冷卻系統(tǒng)帶走(有些用來加熱車廂內(nèi)部)。保持發(fā)動機的溫度平衡對發(fā)動機產(chǎn)生動力是很有必要的。如果發(fā)動機運行過熱，過高的燃燒室溫度會過早點燃混合氣而導(dǎo)致提前點火；機油會粘

24、度下降，熱機油也會形成機油氧化膜和燃燒室積炭，這可能增加HC排放；溫度過高時金屬的性能也與常溫時有所不同，這會導(dǎo)致性能下降和過早磨損，甚至可能導(dǎo)致發(fā)動機損壞。如果發(fā)動機運行溫度過低，燃料汽化效果不好。如果液態(tài)燃料進入氣缸，它將沖刷氣缸壁上的機油，稀釋機油而降低潤滑效果。這也將導(dǎo)致發(fā)動機性能下降、HC排放的增加、發(fā)動機過早磨損。基于此，內(nèi)燃機必須有某種形式的冷卻系統(tǒng)。</p><p>　　在機動車上有兩種類型的冷卻

25、系統(tǒng)，液冷和風(fēng)冷。一些較大的汽車上裝用風(fēng)冷，如原來的大眾甲殼蟲、雪佛蘭考威爾和一些其他車。許多現(xiàn)代摩托車仍然使用風(fēng)冷，但在大多數(shù)情況下，汽車和貨車使用液冷系統(tǒng)，這是本文將集中討論的。</p><p>　　液冷系統(tǒng)的組成部分包括散熱器、散熱器冷卻風(fēng)扇和風(fēng)扇傳動帶、壓力蓋(散熱器蓋)、水泵、恒溫器、旁路系統(tǒng)、防凍塞、缸蓋墊片和進氣歧管墊片、加熱器芯和軟管。具體而言，冷卻系統(tǒng)組成包括在發(fā)動機缸體和缸蓋里的管道(水套)、

26、使冷卻液循環(huán)的水泵、控制冷卻液溫度的恒溫器、使冷卻液冷卻的散熱器、控制冷卻系統(tǒng)壓力的散熱器蓋、一些相互連接的軟管組成的管道裝置，用來將發(fā)動機里冷卻液的熱傳送到散熱器，也傳送給汽車的加熱系統(tǒng)，其中的冷卻液用于在冷天加熱汽車內(nèi)部。</p><p>　　液冷系統(tǒng)是通過在發(fā)動機缸體和缸蓋管道里傳送液態(tài)冷卻液而工作的。當(dāng)冷卻液(低凝點的又稱為防凍液)流過這些通道時，它從發(fā)動機吸收熱量。加熱了的冷卻液通過橡膠管到達車前散熱器

27、。當(dāng)它流過散熱器里的薄壁管時，通過從車前格柵流人的冷空氣將熱液體冷</p><p>　　卻。一旦液體冷卻，它就會返回發(fā)動機，以吸收更多的熱量。水泵的任務(wù)是保持這些液體流過管道和隱藏的通道系統(tǒng)。</p><p>　　恒溫器布置在發(fā)動機和散熱器之間，以確保冷卻液的循環(huán)變化設(shè)定在某一溫度上。如果冷卻液溫度低于此溫度，自動恒溫器就會阻斷冷卻液流向散熱器，迫使其繞流，經(jīng)旁通道而直接回到發(fā)動機。冷卻液

28、將繼續(xù)這樣流動，直至達到設(shè)定溫度，此時，自動恒溫器將打開閥</p><p>　　門，讓冷卻液返回散熱器。當(dāng)系統(tǒng)中冷卻液的溫度達到90度時，恒溫閥全部打開，其傾斜的邊緣切斷較短的路徑(小循環(huán))，使冷卻液通過較長的路徑(大循環(huán))：水泵一冷卻水套一恒溫器一散熱器上部水箱一散熱器芯一下部水箱一水泵。</p><p>　　為了防止冷卻液沸騰，冷卻系統(tǒng)設(shè)計成加壓的。在壓力下，冷卻液沸點大大提高。然而，

29、太大的壓力會導(dǎo)致軟管和其他管路的爆裂，因此如果壓力超過某點，則需要一個系統(tǒng)來減輕壓力。維持冷卻系統(tǒng)壓力的工作歸屬于散熱器蓋。如果達到系統(tǒng)設(shè)計能承載的指定上</p><p>　　限，散熱器蓋就釋放壓力。</p><p>　　水泵設(shè)計有很多種，但多數(shù)是離心式的。它們由一個旋轉(zhuǎn)風(fēng)扇或葉輪組成，很少是齒輪式或活塞容積式的。許多水泵是有一個彈簧加載式密封，以避免在泵軸周圍漏水。一些V形發(fā)動機在每列氣

30、缸有一個水泵。</p><p>　　散熱器是為了散發(fā)熱量的裝置，散發(fā)冷卻液從發(fā)動機吸收熱。它被制造成在管道或其他通道中裝大量水，提供了與大氣接觸的巨大面積。散熱器芯有兩個基本類型，管片式(散熱片位于水管周圍以增加散熱面積)和管帶式(或稱蜂窩式)。</p><p>　　對于新型的發(fā)動機，冷卻系統(tǒng)必須維持足夠有效燃燒的溫度，但又不至于高到使發(fā)動機受到損害。這些要求對于保證精確空燃比、追求良好燃

31、油經(jīng)濟性和排放控制的電控發(fā)動機是非常關(guān)鍵的。</p><p><b>　　變速器油冷卻器</b></p><p>　　自動變速器油由一個小型、獨立的散熱器來冷卻。它通常位于較低的水箱里或主散熱器邊上。發(fā)動機冷卻液的唯一作用是保持缸體和其上的發(fā)動機部件冷卻，但變速器油具有三種</p><p>　　功能：液壓操縱變速器，潤滑變速器內(nèi)部，并保持變速器

32、在適當(dāng)?shù)墓ぷ鳒囟确秶鷥?nèi)。</p><p>　　大多數(shù)車輛可受益于變速器油冷卻器的安裝，特別是如果車輛是用來拉拖車或用于某些重載運輸?shù)摹?lt;/p><p><b>　　機油冷卻器</b></p><p>　　一些車輛，特別是采用高性能發(fā)動機或柴油發(fā)動機的車上，均配備機油冷卻器。機油冷卻器可位于散熱器水箱里(類似于變速器油冷卻器)，或單獨安裝在靠近發(fā)