汽車制動系統(tǒng)外文翻譯

1、<p>　　Automobile Brake System</p><p>　　The braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which con

2、vert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes, the driver commands a stopping force ten times as powerful as the force that puts the car in motion. The braking s

3、ystem can exert thousands of pounds of pressure on each of the four brakes.</p><p>　　Two complete independent braking systems are used on the car. They are the service brake and the parking brake.</p>

4、<p>　　The service brake acts to slow, stop, or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. The primary purpose of the brake is to hold the

5、vehicle stationary while it is unattended. The parking brake is mechanically operated by when a separate parking brake foot pedal or hand lever is set.</p><p>　　The brake system is composed of the following

6、basic components: the “master cylinder” which is located under the hood, and is directly connected to the brake pedal, converts driver foot’s mechanical pressure into hydraulic pressure. Steel “brake lines” and flexible

7、“brake hoses” connect the master cylinder to the “slave cylinders” located at each wheel. Brake fluid, specially designed to work in extreme conditions, fills the system. “Shoes” and “pads” are pushed by the slave cylind

8、ers to contact</p><p>　　The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the

9、master cylinder (Figure).</p><p>　　Basically, all car brakes are friction brakes. When the driver applies the brake, the control device forces brake shoes, or pads, against the rotating brake drum or disks a

10、t wheel. Friction between the shoes or pads and the drums or disks then slows or stops the wheel so that the car is braked.</p><p>　　In most modern brake systems (see Figure 15.1), there is a fluid-filled cy

11、linder, called master cylinder, which contains two separate sections, there is a piston in each section and both pistons are connected to a brake pedal in the driver’s compartment. When the brake is pushed down, brake fl

12、uid is sent from the master cylinder to the wheels.</p><p>　　At the wheels, the fluid pushes shoes, or pads, against revolving drums or disks. The friction between the stationary shoes, or pads, and the revo

13、lving drums or disks slows and stops them. This slows or stops the revolving wheels, which, in turn, slow or stop the car.</p><p>　　The brake fluid reservoir is on top of the master cylinder. Most cars today

14、 have a transparent r reservoir so that you can see the level without opening the cover. The brake fluid level will drop slightly as the brake pads wear. This is a normal condition and no cause for concern. If the level

15、drops noticeably over ashort period of time or goes down to about two thirds full, have your brakes checked as soon as possible. Keep the reservoir covered except for the amount of time you need to fill it</p><

16、;p>　　The brake fluid travels from the master cylinder to the wheels through a series of steel tubes and reinforced rubber hoses. Rubber hoses are only used in places that require flexibility, such as at the front whee

17、ls, which move up and down as well as steer. The rest of the system uses non-corrosive seamless steel tubing with special fittings at all attachment points. If a steel line requires a repair, the best procedure is to rep

18、lace the compete line. If this is not practical, a line can be repai</p><p>　　Drum brakes, it consists of the brake drum, an expander, pull back springs, a stationary back plate, two shoes with friction lini

19、ngs, and anchor pins. The stationary back plate is secured to the flange of the axle housing or to the steering knuckle. The brake drum is mounted on the wheel hub. There is a clearance between the inner surface of the d

20、rum and the shoe lining. To apply brakes, the driver pushes pedal, the expander expands the shoes and presses them to the drum. Friction between the br</p><p>　　Disk brakes, it has a metal disk instead of a

21、drum. A flat shoe, or disk-brake pad, is located on each side of the disk. The shoes squeeze the rotatin g disk to stop the car. Fluid from the master cylinder forces the pistons to move in, toward the disk. This action

22、pushes the friction pads tightly against the disk. The friction between the shoes and disk slows and stops it. This provides the braking action. Pistons are made of either plastic or metal. There are three general types

23、of disk brakes</p><p>　　The brake system assemblies are actuated by mechanical, hydraulic or pneumatic devices. The mechanical leverage is used in the parking brakes fitted in all automobile. When the brake

24、pedal is depressed, the rod pushes the piston of brake master cylinder which presses the fluid. The fluid flows through the pipelines to the power brake unit and then to the wheel cylinder. The fluid pressure expands the

25、 cylinder pistons thus pressing the shoes to the drum or disk. If the pedal is released, the pist</p><p>　　The primary purpose of the parking brake is to hold the vehicle stationary while it is unattended. T

26、he parking brake is mechanically operated by the driver when a separate parking braking hand lever is set. The hand brake is normally used when the car has already stopped. A lever is pulled and the rear brakes are appro

27、ached and locked in the “on” position. The car may now be left without fear of its rolling away. When the driver wants to move the car again, he must press a button before the leve</p><p>　　Anti-lock Brake S

28、ystem</p><p>　　Anti-lock brake systems make braking safer and more convenient, Anti-lock brake systems modulate brake system hydraulic pressure to prevent the brakes from locking and the tires from skidding

29、on slippery pavement or during a panic stop.</p><p>　　Anti-lock brake systems have been used on aircraft for years, and some domestic car were offered with an early form of anti-lock braking in late 1990’s.

30、Recently, several automakers have introduced more sophisticated anti-lock system. Investigations in Europe, where anti-lock brakin g systems have been available for a decade, have led one manufacture to state that the nu

31、mber of traffic accidents could be reduced by seven and a half percent if all cars had anti-lock brakes. So some sources predic</p><p>　　Anti-lock systems modulate brake application force several times per s

32、econd to hold the tires at a controlled amount of slip; all systems accomplish this in basically the same way. One or more speed sensors generate alternating current signal whose frequency increases with the wheel rotati

33、onal speed. An electronic control unit continuously monitors these signals and if the frequency of a signal drops too rapidly indicating that a wheel is about to lock, the control unit instructs a modulating de</p>

34、<p>　　In addition to their basic operation, anti-lock systems have two other things in common. First, they do not operate until the brakes are applied with enough force to lock or nearly lock a wheel. At all other

35、 times, the system stands ready to function but does not interfere with normal braking. Second, if the anti-lock system fail in any way, the brakes continue to operate without anti-lock capability. A warning light on the

36、 instrument panel alerts the driver when a problem exists in the anti-loc</p><p>　　The current Bosch component Anti-lock Braking System (ABSⅡ), is a second generation design wildly used by European automaker

37、s such as BWM, Mercedes-Benz and Porsche. ABSⅡ system consists of : four wheel speed sensor, electronic control unit and modulator assembly.</p><p>　　A speed sensor is fitted at each wheel sends signals abou

38、t wheel rotation to control unit. Each speed sensor consists of a sensor unit and a gear wheel. The front sensor mounts to the steering knuckle and its gear wheel is pressed onto the stub axle that rotates with the wheel

39、. The rear sensor mounts the rear suspension member and its gear wheel is pressed onto the axle. The sensor itself is a winding with a magnetic core. The core creates a magnetic field around the winding, and as the teeth

40、 of</p><p>　　The control unit’s function can be divided into three parts: signal processing, logic and safety circuitry. The signal processing section is the converter that receives the alternating current s

41、ignals form the speed sensors and converts them into digital form for the logic section. The logic section then analyzes the digitized signals to calculate any brake pressure changes needed. If impending lockup is sensed

42、, the logic section sends commands to the modulator assembly.</p><p>　　Modulator assembly</p><p>　　The hydraulic modulator assembly regulates pressure to the wheel brakes when it receives comman

43、ds from the control utuit. The modulator assembly can maintain or reduce pressure over the level it receives from the master cylinder, it also can never apply the brakes by itself. The modulator assembly consists of thre

44、e high-speed electric solenoid valves, two fluid reservoirs and a turn delivery pump equipped with inlet and outlet check valves. The modulator electrical connector and controlling rela</p><p>　　Each front w

45、heel is served by electric solenoid valve modulated independently by the control unit. The rear brakes are served by a single solenoid valve and modulated together using the select-low principle. During anti-braking syst

46、em operation, the control unit cycles the solenoid valves to either hold or release pressure the brake lines. When pressure is released from the brake lines during anti-braking operation, it is routed to a fluid reservoi

47、r. There is one reservoir for the front brake ci</p><p><b>　　汽車制動系統(tǒng)</b></p><p>　　制動系統(tǒng)是汽車中最重要的系統(tǒng)。 如果制動失靈，結(jié)果可能是損失慘重的。制動器實際就是能量轉(zhuǎn)換裝置，它將汽車的動能（動量）轉(zhuǎn)化成熱能（熱量）。當(dāng)駕駛員踩下制動踏板，所產(chǎn)生的制動力是汽車運動時動力的10倍。制

48、動系統(tǒng)能對四個剎車系統(tǒng)中的每個施加數(shù)千磅的力。</p><p>　　每輛汽車上使用兩個完全獨立的制動系統(tǒng)，即行車制動器和駐車制動器。</p><p>　　行車制動器起到減速、停車、或保持車輛正常行駛。制動器是由司機(jī)用腳踩、松制動器踏板來控制的。駐車制動器的主要作用就是當(dāng)車內(nèi)無人的時候，汽車能夠保持靜止。當(dāng)獨立的駐車制動器—踏板或手桿，被安裝時，駐車制動器就會被機(jī)械地操作。</p>

49、;<p>　　制動系統(tǒng)是由下列基本的成分組成:位于發(fā)動機(jī)罩下方，而且直接地被連接到制動踏板的“制動主缸”把駕駛員腳的機(jī)械力轉(zhuǎn)變?yōu)橐簤毫Αｄ撝频摹爸苿庸苈贰焙陀腥嵝缘摹爸苿榆浌堋卑阎苿又鞲走B接到每個輪子的“制動輪缸”上。 制動液, 特別地設(shè)計為的是工作在極端的情況，填充在系統(tǒng)中。“制動盤”和“襯塊”是被制動輪缸推動接觸“圓盤”和“回轉(zhuǎn)體”如此引起緩慢的拖拉運動, (希望)使汽車減慢速度。</p><p&g

50、t;　　典型的制動系統(tǒng)布置有前后盤式，前盤后鼓式，各個車輪上的制動器通過一套管路系統(tǒng)連接到制動主缸上。</p><p>　　基本上講，所有的汽車制動器都是摩擦制動器。當(dāng)司機(jī)剎車時，控制裝置會迫使制動蹄，或制動襯片與車輪處的旋轉(zhuǎn)的制動鼓或制動盤接觸。接觸后產(chǎn)生的摩擦使車輪轉(zhuǎn)動減慢或停止，這就是汽車的制動。</p><p>　　在最基本的制動系統(tǒng)中，有一個制動主缸，這個主缸內(nèi)部填充制動液，并包

51、含兩個部分，每個部分里都有一個活塞，兩個活塞都連接駕駛室里的制動踏板。當(dāng)制動踏板被踩下時，制動液會從制動主缸流入輪缸。在輪缸中，制動液推動制動蹄或制動襯片與旋轉(zhuǎn)的制動鼓或制動盤接觸。靜止的制動蹄或制動襯片與旋轉(zhuǎn)的制動鼓或制動盤之間產(chǎn)生摩擦力使汽車的運動逐漸減緩或停止。</p><p>　　制動液的裝置位于主缸的頂部。目前大多數(shù)的車都有一個容易看見的裝制動液的裝置，為的是不用打開蓋子就可以看得見制動液的油面。隨著制

52、動踏板的運動制動液就會緩慢的下降，正常情況下是這樣的。如果制動液在很短的時間內(nèi)下降得明顯或者下降了三分之二，那么就要盡快的檢查你的制動系統(tǒng)了。保持制動液裝置充滿制動液除非你需要維修它，制動液必須保持很高的沸點。位于在空氣中的制動液就會吸收空氣中的潮氣引起制動液低于沸點。</p><p>　　制動液通過一系列的管路從主缸到達(dá)各車輪。橡膠軟管只用在需要彈力的地方，比如應(yīng)用在前輪。在車的行進(jìn)中上下來回運動。系統(tǒng)的其它部

53、分在所有的連接點上都應(yīng)用了無腐蝕性的無縫鋼管。如果鋼線需要修理的話，最好的方法就是代替這條線。如果這不符合實際，那么為了制動系統(tǒng)可以用特殊的裝置修理它。你不可以用銅管來修理制動系。它們是危險也是不正確的。</p><p>　　鼓式制動器包括制動鼓，一個輪缸，回拉彈簧，一個制動底版，兩個帶摩擦層的制動蹄。制動底版固定在輪軸外部的法蘭或轉(zhuǎn)向節(jié)。制動鼓固定在輪轂上。制動鼓的內(nèi)部表面與制動蹄的內(nèi)層之間有空隙。要使用制動器

54、時，司機(jī)就要踩下踏板，這時輪缸擴(kuò)大制動片，對其施加壓力，是制動蹄觸碰制動鼓。制動鼓與摩擦片之間產(chǎn)生的摩擦制動了車輪，從而使汽車停止。要釋放制動器時，司機(jī)松開踏板，回拉彈簧拉回制動片，這樣車輪會自由轉(zhuǎn)動。</p><p>　　盤式制動器包括制動盤而不是鼓，在它的兩面上各有一個薄的制動片或叫盤式制動器的制動片。制動片是靠擠住旋轉(zhuǎn)的制動盤來停住汽車。制動主缸里流出的制動液迫使活塞向里部的金屬盤移動，這便使摩擦片緊緊地貼

55、住制動盤。這時制動片與制動盤產(chǎn)生的摩擦使汽車減速、停止，出現(xiàn)了制動行為。活塞分金屬或塑料。盤式制動器主要有三種，即：浮動卡鉗型、固定卡鉗型和滑動卡鉗型。浮動卡鉗型和滑動卡鉗型盤式制動器使用單活塞。固定卡鉗型盤式制動器既可以使用兩個活塞有可以使用四個活塞。</p><p>　　制動系統(tǒng)是由機(jī)械能，液壓能或氣壓能裝置驅(qū)動的。在機(jī)械杠桿適合所有的汽車的駐車制動器中使用。當(dāng)踩下制動踏板時，杠桿就會推動制動器主缸的活塞給制

56、動液施加壓力，制動液通過油管流入輪缸。制動液的壓力施加到輪缸活塞以使制動片被壓到制動鼓或制動盤上。如果松開踏板，活塞回到原來的位置上，回拉彈簧拉回制動片，制動液返回制動主缸，這樣制動停止。</p><p>　　駐動制動器的主要作用是車內(nèi)無人時，使汽車靜止不動。如果車內(nèi)安裝的是獨立的駐車制動器，那么駐車制動器是由司機(jī)手動的控制。駐車制動器正常是當(dāng)車已經(jīng)停止時使用的。向后拉手閘，并把手柄卡在正確的位置上?，F(xiàn)在，即使離

57、開汽車也不用害怕它會自己滑走。如果司機(jī)要再次啟車時，他必須在松開手桿之前按下按鈕。在行車制動器失靈的情況下，手閘必須能停住車。正因為這樣，手閘與腳閘分開，手閘使用的是繩索或杠桿而不是液力系統(tǒng)。</p><p>　　防抱死制動系統(tǒng)是使汽車制動更安全、更方便的制動裝置，它既有調(diào)節(jié)制動系統(tǒng)的壓力來防止車輪被完全抱死的功能，又有防止輪胎在滑的路面上行駛或緊急停車時的滑動。</p><p>　　防抱

58、死制動系統(tǒng)最早應(yīng)用在航空飛行器上，而且在二十世紀(jì) 90年代一些國內(nèi)的汽車內(nèi)也安裝了這種系統(tǒng)。近來，幾個汽車制造商引進(jìn)了更為復(fù)雜的防抱死系統(tǒng)。歐洲使用這種系統(tǒng)已有幾十年的時間，通過對其的調(diào)查，一位汽車制造商坦言，如果所有的汽車都安裝上防抱死制動系統(tǒng)，那么交通事故的發(fā)生率會降低7.5%。同時，一些權(quán)威人士預(yù)測這種系統(tǒng)會提高汽車的安全性。</p><p>　　防抱死制動系統(tǒng)可以在一秒鐘內(nèi)調(diào)節(jié)幾次制動時車輪上的受力，使車

59、輪的滑移受到控制，而且所有的系統(tǒng)基本上都以相同的方式完成。每個車輪都會有一個傳感器，電子控制裝置能連續(xù)檢測來自車輪傳感器傳來的脈沖電信號，并將它們處理轉(zhuǎn)換成和輪速成正比的數(shù)值；如果其中一個傳感器的信號不斷下降，那么這就表明了相應(yīng)的輪胎趨于抱死，這時電子控制裝置向該車輪的制動器發(fā)出降低壓力的指令。當(dāng)信號顯示車輪轉(zhuǎn)速恢復(fù)正常時，電子控制裝置會增加制動器的液壓。這種循環(huán)像司機(jī)一樣調(diào)節(jié)制動器，但它的速度更快，達(dá)到了每秒循環(huán)數(shù)次。</p&g

60、t;<p>　　防抱死制動系統(tǒng)除了上面基本操作，還有兩個特點。首先，當(dāng)制動系統(tǒng)的壓力上升到使輪胎抱死或即將抱死的時候，防抱死制動系統(tǒng)才會啟動；當(dāng)制動系統(tǒng)在正常情況下，防抱死制動系統(tǒng)停止運作。其次，如果防抱死制動系統(tǒng)有問題時，制動器會獨立地繼續(xù)運行。但控制板上的指示燈亮起提醒司機(jī)系統(tǒng)出現(xiàn)問題。</p><p>　　目前歐洲汽車生產(chǎn)商，如：寶馬、奔馳、寶時捷等廣泛使用的是波許（Bosch）防抱死制動系統(tǒng)

61、。這種系統(tǒng)基本組成包括車輪轉(zhuǎn)速傳感器，電子控制裝置和調(diào)節(jié)裝置。</p><p>　　每個有一個向電子控制裝置發(fā)出車輪轉(zhuǎn)動情況的信號的傳感器，它一般由磁感應(yīng)傳感頭和齒圈組成。前面的傳感器安在輪轂上，齒圈安在輪網(wǎng)上。后面的傳感器安在后部的監(jiān)測系統(tǒng)上，齒圈安在輪軸上。傳感器本身是纏繞電磁核的電線圈，電磁核才線圈的周圍產(chǎn)生磁場。當(dāng)齒圈的齒移動到磁場時，就會改變線圈的電流。電子控制裝置會監(jiān)測這種變化，然后判斷車輪是否即將抱

62、死。</p><p>　　電子控制裝置有三個作用，即：信號的處理，編輯和安全防護(hù)。信號的處理起到轉(zhuǎn)換器的作用，它是將接受的脈沖電信號處理轉(zhuǎn)換成數(shù)值，為編輯做準(zhǔn)備。編輯就是分析這些數(shù)值，計算出需要制動壓力。如果檢測出車輪即將抱死，電控裝置就會計算出數(shù)值向調(diào)節(jié)裝置發(fā)出指令。</p><p><b>　　調(diào)節(jié)裝置</b></p><p>　　當(dāng)接受到

63、電子控制裝置的指令后，液壓執(zhí)行裝置會調(diào)節(jié)制動輪缸的液壓的大小。調(diào)節(jié)裝置能保持或減小來自制動主缸的液壓，而裝置本身是不能啟用制動器的。這種裝置有三個高速率的電磁閥，兩個油液存儲器和一個帶有內(nèi)外檢測閥的傳動泵。調(diào)節(jié)裝置中的電子連接器隱藏在塑料蓋下。</p><p>　　每個電磁閥都是其獨立控制的，并作用于前輪。后部的制動輪缸受到一個電磁閥控制，并依照------的原理進(jìn)行調(diào)節(jié)。當(dāng)防抱死制動系統(tǒng)運行時，電子控制裝置會使