汽車專業(yè)英語第二部分6章

1、背景知識背景知識 生詞生詞Unit 6 Cooling System譯文及評析譯文及評析 背景知識背景知識 冷卻系統(tǒng)按照冷卻介質(zhì)不同可以分為風冷和水冷。如果把發(fā)動機中高溫零件的熱量直接散入大氣而進行冷卻的裝置稱為風冷系統(tǒng)。而把這些熱量先傳給冷卻水，然后再散入大氣而進行冷卻的裝置稱為水冷系統(tǒng)。由于水冷系統(tǒng)冷卻均勻，效果好，而且發(fā)動機運轉(zhuǎn)噪音小，目前汽車發(fā)動機上廣泛采用的是水冷系統(tǒng)。生詞生詞liquid n.液體，流體 grill n. 散熱格absorb vt.吸收；吸引 thermostat n. 節(jié)溫器，恒溫器reservoir n.儲液器 core n.核心aluminum n.鋁 fin

2、 n.散熱片via prep.取道，通過；經(jīng)由 fluid n.流體；液體ethylene n.乙烯 glycol n. 乙二醇；甘醇；二羥基醇maintain vt.維持；維修 release vt. 釋放；發(fā)射Pressurize vt.密封；增壓 vacuum n. 真空serpentine adj. 陰險的；蜿蜒的；彎彎曲曲的block vt阻塞；阻止 bypass n. 旁路；支路heater n.加熱器 interior adj.內(nèi)部的；國內(nèi)的；本質(zhì)的version n.譯文；版本譯文及評析譯文及評析 A cooling system works by sending a liqu

3、id coolant through passages in the engine block and heads. As the coolant flows through these passages, it picks up heat from the engine. The heated coolant then passes through a rubber hose to the top inlet of the radiator in front of the car. The coolant flows down through the thin tubes in the ra

4、diator; the hot coolant is cooled by the air stream entering the engine compartment from the grill in front of the car. Cooling system ：冷卻系統(tǒng)過了一會，小男孩不哭了，睜開眼睛，過了一會，小男孩不哭了，睜開眼睛，用詢問的目光看著越南護士。用詢問的目光看著越南護士。 通過向發(fā)動機缸體和缸蓋的管道傳送冷卻液，汽車的冷卻系統(tǒng)進行工作。當冷卻液流過這些通道時，它從發(fā)動機中吸收熱量，從而降低發(fā)動機的溫度。冷卻液流過發(fā)動機后，經(jīng)橡膠軟管到達汽車前端散熱器。熱的冷卻液進入散

5、熱器薄壁管，通過向汽車前端散熱格柵吹入冷空氣進行熱量交換，熱的冷卻液被冷卻。譯文及評析譯文及評析 Once the coolant has made its way to the bottom of the radiator and is cooled it returns to the engine through a rubber hose to absorb more heat. The water pump has the job of keeping the fluid moving through the entire system. Coolant: 冷卻劑過了一會，小男孩不哭了

6、，睜開眼睛，過了一會，小男孩不哭了，睜開眼睛，用詢問的目光看著越南護士。用詢問的目光看著越南護士。 冷卻液冷卻后，到達散熱器下端出口，經(jīng)橡膠軟管返回發(fā)動機吸收更多的熱量。水泵的主要任務是保持液體在系統(tǒng)內(nèi)的循環(huán)流動。譯文及評析譯文及評析 A cooling system include the following typical components:Radiator, pressure cap, transmission cooler, fan, water pump, rubber hoses, thermostat, reservoir tank, and heater core.掌握基本

7、的名詞詞匯及上文內(nèi)容掌握基本的名詞詞匯及上文內(nèi)容過了一會，小男孩不哭了，睜開眼睛，過了一會，小男孩不哭了，睜開眼睛，用詢問的目光看著越南護士。用詢問的目光看著越南護士。 冷卻系統(tǒng)包括以下典型組成部分：散熱器，散熱器蓋，變速箱冷卻器，冷卻風扇，水泵，橡膠軟管，節(jié)溫器，補償水桶，以及暖風機芯譯文及評析譯文及評析 On most cars today the radiator is made of thin aluminum tubes with aluminum fins that zigzag between the tubes. Air is pulled through the fins v

8、ia cooling fans causing the heat in the radiator to be transferred into the air stream and carried away from the vehicle. The radiator has two tanks, one for inlet of heated coolant and the other for outlet of the cooled fluid.掌握上文基本內(nèi)容。掌握上文基本內(nèi)容。過了一會，小男孩不哭了，睜開眼睛，過了一會，小男孩不哭了，睜開眼睛，用詢問的目光看著越南護士。用詢問的目光看著

9、越南護士。 如今，大多數(shù)汽車散熱器是用鋁合金散熱管和波紋狀鋁合金散熱片制成。冷卻風扇向散熱器吹入外部冷空氣，熱量散發(fā)到空氣中，通過空氣介質(zhì)將熱量帶離出去。散熱器有兩個水室，一個是熱的液體進水室，另一個是冷卻后液體出水室。譯文及評析譯文及評析 The cooling system is sealed. When the coolant gets hot it expands and causes an increase in pressure in the cooling system. When coolant is under pressure the boiling point of th

10、e liquid becomes higher. Coolant is made with ethylene glycol, which has a higher boiling point than water, along with keeping it under pressure allows the coolant to safely reach temperatures in excess of 250 degrees.過了一會，小男孩不哭了，睜開眼睛，過了一會，小男孩不哭了，睜開眼睛，用詢問的目光看著越南護士。用詢問的目光看著越南護士。 冷卻系統(tǒng)是密封的。當冷卻液吸收熱量后，其溫

11、度逐漸升高，容積膨脹，使冷卻系統(tǒng)內(nèi)的壓力增高。當系統(tǒng)壓力處在大氣壓力之下時，冷卻液的沸點會變得更高。冷卻劑主要由乙二醇制成，沸點比水高，保持在允許的氣壓下，冷卻液可以在250度甚至以上的溫度下處于安全狀態(tài)。譯文及評析譯文及評析 The pressure cap is a simple device that will maintain the pressure in the system to a certain point. If the pressure builds up higher than the set pressure point there is a spring loade

12、d valve that allows the pressure to release. During this process a small amount of coolant is bled off into the reservoir tank which is not pressurized. Since there is less coolant in the system, as the engine cools down a partial vacuum is formed. The radiator cap on these closed systems has a seco

13、ndary valve to allow the vacuum in the cooling system to draw the coolant back into the radiator from the reservoir tank.過了一會，小男孩不哭了，睜開眼睛，過了一會，小男孩不哭了，睜開眼睛，用詢問的目光看著越南護士。用詢問的目光看著越南護士。 散熱器蓋是一個簡易的裝置，維持系統(tǒng)壓力穩(wěn)定于某一值。如果壓力增高超過預定值，壓力閥開啟，以釋放壓力。在這一過程中，一部分冷卻液流出，經(jīng)溢流管流入未加壓的補償水桶。當發(fā)動機停機后，由于系統(tǒng)中冷卻液不足，發(fā)動機溫度下降，系統(tǒng)內(nèi)壓力低于大氣壓

14、出現(xiàn)局部真空，散熱器蓋下端真空閥開啟，補償水桶內(nèi)的冷卻液部分地流回散熱器。譯文及評析譯文及評析 A water pump is a simple device that will keep the coolant moving through the system as long as the engine is running. The pump is driven by either a fan belt which usually drives another component, a serpentine belt which drives all components, a timi

15、ng belt, or in some cases gear driven.Serpentine belt: 蛇形皮帶 過了一會，小男孩不哭了，睜開眼睛，過了一會，小男孩不哭了，睜開眼睛，用詢問的目光看著越南護士。用詢問的目光看著越南護士。 水泵是一個簡易的裝置，在發(fā)動機正常運轉(zhuǎn)過程中保持冷卻液在系統(tǒng)中的正常循環(huán)流動。水泵一般由發(fā)動機的曲軸通過帶輪驅(qū)動，可以由為單個部件提供動力的風扇帶輪或是為整個部件提供動力的蛇形皮帶驅(qū)動，還可以由一個正時帶輪驅(qū)動，在某些情況下可以齒輪驅(qū)動。譯文及評析譯文及評析 The thermostat is simply a valve that measures th

16、e temperature of the coolant and, if it is hot enough, opens to allow the coolant to flow to the radiator. If the coolant is not hot enough, the flow to the radiator is blocked and fluid is directed back to the engine via a bypass system. Because flow to the radiator is blocked, the engine will reac

17、h operating temperature sooner and, on a cold day, will allow the heater to begin supplying hot air to the interior more quickly.Thermostat: 恒溫器 過了一會，小男孩不哭了，睜開眼睛，過了一會，小男孩不哭了，睜開眼睛，用詢問的目光看著越南護士。用詢問的目光看著越南護士。 節(jié)溫器是控制冷卻液流動路徑的閥門，它根據(jù)冷卻液溫度高低，打開或關(guān)閉冷卻液通向散熱器的通道。如果冷卻液溫度過高，閥門打開，冷卻液流向散熱器。如果冷卻液溫度較低，節(jié)溫器閥門關(guān)閉，冷卻液經(jīng)旁路系

18、統(tǒng)直接返回發(fā)動機。由于散熱器流入通道被堵，發(fā)動機很快達到正常運行溫度，在一個較冷的日子，熱的冷卻液流入暖風機，向車廂內(nèi)部供應暖氣。The hot coolant is also used to provide heat to the interior of the vehicle when needed. The heater core looks like a small version of a radiator, connected to the cooling system with a pair or rubber hoses. One hose brings hot coolant to the heater core and the