附錄 1 英文參考資料 Automobile Brake System 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 convert 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 system can exert thousands of pounds of pressure on each of the four brakes. Two complete independent braking systems are used on the car.They are the service brake and the parking brake. 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 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. The brake system is composed of the following basic components:the “master cylinder”which is located under the hood,and is directly connected to the brake pedal,converts driver foots mechanical pressure into hydraulic pressure.Steel“brake lines”and flexible“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 cylinders to contact the“drums”and“rotors”thus causing drag,which (hopefully) slows the car. In most modern brake systems (see Figure 15.1),there is a fluid-filled cylinder,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 drivers compartment.When the brake is pushed down,brake fluid is sent from the master cylinder to the wheels.At the wheels,the fluid pushes shoes,or pads, against revolving drums or disks.The friction between the stationary shoes,or pads,and the revolving drums or disks slows and stops them.This slows or stops the revolving wheels,which,in turn,slow or stop the car. Drum brakes,it consists of the brake drum,an expander,pull back springs, a stationary back plate,two shoes with friction linings,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 drum 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 brake drum and the friction linings brakes the wheels and the vehicle stops.To release brakes， the driver release the pedal,the pull back spring retracts the shoes thus permitting free rotation of the wheels. 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 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 cylinder pistons thus pressing the shoes to the drum or disk. If the pedal is released,the piston returns to the initial position,the pull back springs retract the shoes,the fluid is forced back to the master cylinder and braking ceases. 附錄 2 譯文 汽車制動(dòng)系統(tǒng) 制動(dòng)系統(tǒng)是汽車中最重要的系統(tǒng)。 如果制動(dòng)失靈，結(jié)果可能是損失慘重的。制動(dòng)器實(shí)際就是能量轉(zhuǎn)換裝置，它將汽車的動(dòng)能（動(dòng)量）轉(zhuǎn)化成熱能（熱量）。當(dāng)駕駛員踩下制動(dòng)踏板，所產(chǎn)生的制動(dòng)力是汽車運(yùn)動(dòng)時(shí)動(dòng)力的 10倍。制動(dòng)系統(tǒng)能 對四個(gè)剎車系統(tǒng)中的每個(gè)施加數(shù)千磅的力。 每輛汽車上使用兩個(gè)完全獨(dú)立的制動(dòng)系統(tǒng)，即行車制動(dòng)器和駐車制動(dòng)器。 行車制動(dòng)器起到減速、停車、或保持車輛正常行駛。制動(dòng)器是由司機(jī)用腳踩、松制動(dòng)器踏板來控制的。駐車制動(dòng)器的主要作用就是當(dāng)車內(nèi)無人的時(shí)候，汽車能夠保持靜止。當(dāng)獨(dú)立的駐車制動(dòng)器 踏板或手桿，被安裝時(shí)，駐車制動(dòng)器就會(huì)被機(jī)械地操作。 制動(dòng)系統(tǒng)是由下列基本的成分組成 :位于發(fā)動(dòng)機(jī)罩下方，而且直接地被連接到制動(dòng)踏板的“制動(dòng)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?dòng)管路”和有柔性的“制動(dòng)軟管”把制動(dòng)主缸連接到每個(gè)輪 子的“制動(dòng)輪缸”上。 制動(dòng)液， 特別地設(shè)計(jì)為的是工作在極端的情況，填充在系統(tǒng)中。“制動(dòng)盤”和“襯塊”是被制動(dòng)輪缸推動(dòng)接觸“圓盤”和“回轉(zhuǎn)體”如此引起緩慢的拖拉運(yùn)動(dòng)， (希望 )使汽車減慢速度。 在最基本的制動(dòng)系統(tǒng)中，有一個(gè)制動(dòng)主缸，這個(gè)主缸內(nèi)部填充制動(dòng)液，并包含兩個(gè)部分，每個(gè)部分里都有一個(gè)活塞，兩個(gè)活塞都連接駕駛室里的制動(dòng)踏板。當(dāng)制動(dòng)踏板被踩下時(shí)，制動(dòng)液會(huì)從制動(dòng)主缸流入輪缸。在輪缸中，制動(dòng)液推動(dòng)制動(dòng)蹄或制動(dòng)襯片與旋轉(zhuǎn)的制動(dòng)鼓或制動(dòng)盤接觸。靜止的制動(dòng)蹄或制動(dòng)襯片與旋轉(zhuǎn)的制動(dòng)鼓或制動(dòng)盤之間產(chǎn)生摩擦力使汽車的運(yùn)動(dòng)逐 漸減緩或停止。 鼓式制動(dòng)器包括制動(dòng)鼓，一個(gè)輪缸，回拉彈簧，一個(gè)制動(dòng)底版，兩個(gè)帶摩擦層的制動(dòng)蹄。制動(dòng)底版固定在輪軸外部的法蘭或轉(zhuǎn)向節(jié)。制動(dòng)鼓固定在輪轂上。制動(dòng)鼓的內(nèi)部表面與制動(dòng)蹄的內(nèi)層之間有空隙。使用制動(dòng)器時(shí)，司機(jī)就要踩下踏板，這時(shí)輪缸擴(kuò)大制動(dòng)片，對其施加壓力，是制動(dòng)蹄觸碰制動(dòng)鼓。制動(dòng)鼓與摩擦片