Unit 7 Suspension SystemPartI Technical and Practical PartI Technical and Practical ReadingReading Passage ASuspension ComponentsThe components of the suspension system perform six basic functions: 1. Maintain correct vehicle ride height 2. Reduce the effect of shock forces 3. Maintain correct wheel alignment 4. Support vehicle weight 5. Keep the tires in contact with the road 6. Control the vehicles direction of travel So all the suspension components must be in good working condition. There are three fundamental components of any suspension: springs, shock absorber and anti-sway bar. See figure 7-1. Figure 7-1 Springs Springs The springs are a very important component of the suspension system that provides ride comfort. The springs support the weight of the car, maintain ride height, and absorb road shock. Springs are the compressible link between the frame and the body. When the car meets a bump in the road, the springs will absorb the load by compressing. There are four major spring designs in use today: coil spring, leaf spring, torsion bar, and air spring.Coil Spring Coil Spring This is the most common type of spring. The coil spring is a length of round spring steel rod that is wound into a coil. Coil springs compress and expand to absorb the motion of the wheels. It requires no adjustment and for the most part is trouble-free. See figure 7-2.Figure 7-2Leaf Spring Leaf Spring This type of spring consists of several layers of steel plates (called “leaves”)of different lengths stacked together to act as a single unit. The leaf springs bend and slide on each other allowing suspension movement. They are still used today on most trucks and heavy-duty vehicles. See figure 7-3.Figure 7-3Torsion Bar Torsion Bar The torsion bar is a straight or L shaped bar of spring steel. One end of a bar is anchored to the vehicle frame. The other end is attached to a wishbone. When the wheel hits a bump, vertical motion is transferred to the wishbone and then, through the levering action, to the torsion bar providing spring action. See figure 7-4. Figure 7-4 Air SpringAir Spring The air spring is another type of spring that is becoming more popular on passenger cars. The air spring is a rubber cylinder filled with compressed air. A piston attached to the lower control arm moves up and down with the lower control arm. This causes the compressed air to provide spring action. See figure 7-5. Figure 7-5Shock AbsorberShock Absorber Shock absorber is a device that controls unwanted spring motion, which is important in keeping the tires in firm contact with the road. Shock absorbers control spring movements in both directions: when the spring is compressed and when it is extended. Without shock absorber, the spring will extend and release the energy which may allow the tires to lose contact with the road. A shock absorber is basically an oil pump placed between the frame of the car and the wheels. The upper mount of the shock absorber connects to the frame, while the lower mount connects to the axle, near the wheel. See figure 7-6.Figure 7-6 When the car wheel meets a bump in the road and causes the spring to coil and uncoil, the energy of the spring is transferred to the shock absorber through the upper mount, down through the piston rod and into the piston. Orifices perforate the piston and allow fluid to leak through as the piston moves up and down in the pressure tube. Because the orifices are relatively tiny, only a small amount of fluid, under great pressure, passes through. This slows down the piston, which in turn slows down the spring.Anti-sway BarAnti-sway Bar Another important component of a suspension system is the anti-sway bar. This device is used along with shock absorbers to give a moving car additional stability. The anti-sway bar is simply a metal rod connected to both of the lower control arms. See figure 7-7.Figure 7-7 When the suspension at one wheel moves up and down the anti-sway bar transfers the movement to the other wheel. This creates a more level ride and reduces vehicle sway. In particular, it combats the roll of a car on its suspension as it corners. For this reason, almost all cars today are fitted with anti-sway bars as standard equipment, although if theyre not, kits make it easy to install the bars at any time. New Wordsalignment lainmnt n. 调整（成直线）调整（成直线）tire tai n. 轮胎轮胎fundamental 7fndmentl a. 基本的基本的，根本的，根本的shock k n. 震动，冲击震动，冲击compressible kmpresbl a. 可压缩的可压缩的link lik n. 联结，构件，链接联结，构件，链接frame freim n. 框，结构，车架框，结构，车架bump bmp n. 撞击，隆起物，颠簸而行碰撞撞击，隆起物，颠簸而行碰撞load lud n. 负荷负荷, 载荷，装载量载荷，装载量expand ikspnd v. 使使膨胀，扩张膨胀，扩张adjustment stmnt n. 调整调整trouble-free 5trblfri: 无故障的（不发生事故的）无故障的（不发生事故的）layer lei n. 层层plate pleit n. 金属板，板材金属板，板材stack stk v. 堆积，堆叠堆积，堆叠bend bend v. 弯曲弯曲anchor k v. 停泊，抛锚，固定停泊，抛锚，固定wishbone wibun n. 叉骨，叉形杆，叉形臂，叉骨，叉形杆，叉形臂，叉形悬臂叉形悬臂extend ikstend v. 扩充，延伸，伸展扩充，延伸，伸展bounce bauns n. 跳，反跃，弹力跳，反跃，弹力v. 弹跳，使弹跳，使跳跳orifice rifis n. 孔口，节流孔孔口，节流孔perforate p:freit v. 穿孔，凿孔，打孔穿孔，凿孔，打孔stability stbiliti n. 稳定性，安定性，稳稳定性，安定性，稳定度定度combat kmbt v. 奋斗奋斗sway swei n. 摇，摇摆摇，摇摆kit kit n. 装备，工具箱装备，工具箱Phrases and Expressionssuspension system 悬架系统悬架系统ride height 装载高度，悬架装载高度装载高度，悬架装载高度shock absorber 减震器，减振器，缓冲装置减震器，减振器，缓冲装置anti-sway bar 横向推力杆，横向稳定杆，平衡横向推力杆，横向稳定杆，平衡杠杠ride comfort 行驶舒适行驶舒适vertical motion 垂直运动，竖向振动垂直运动，竖向振动coil spring 螺旋弹簧螺旋弹簧leaf spring 板簧，片簧，钢板弹簧板簧，片簧，钢板弹簧torsion bar 扭力杆，扭杆弹簧扭力杆，扭杆弹簧air spring 气垫，空气弹簧，充气弹簧气垫，空气弹簧，充气弹簧lever action 杠杆作用杠杆作用passenger car 乘用车乘用车upper mount 上悬臂架上悬臂架lower mount 下悬臂架下悬臂架lower control arm 下控制臂下控制臂pressure tube 高压管，压力管高压管，压力管level ride 平稳行驶平稳行驶standard equipment 标准设备，标准装备标准设备，标准装备EXERCISE 1 Mark the following statements with T (True) or F (False) according to the passage.EXERCISE 2Translate the following phrases into Chinese or English.1. ride height 2. 横向推力杆横向推力杆3. coil spring 4. 杠杆作用杠杆作用5. suspension system 6. 下控制臂下控制臂7. level ride 8. 扭力杆扭力杆9. upper mount 10. 减震减震器器EXERCISE 3Fill in the blanks with the suitable words or phrases given below, changing the form where necessary.Orificesspringcoil spring leaf springslower mount torsion bar anti-sway barshock absorberair springsuspension system1. are the compressible link between the frame and the body.2. The components of the can maintain correct vehicle ride height. 3. The is a length of round spring steel rod that is wound into a coil.4. The bend and slide on each other allowing suspension movement.5. The is a straight or L shaped bar of spring steel.6. The is a rubber cylinder filled with compressed air.7. is a device that controls unwanted spring motion.8. The upper mount of the shock absorber connects to the frame, while the connects to the axle, near the wheel.9. Because the are relatively tiny, only a small amount of fluid, under great pressure, passes through.10. The is simply a metal rod connected to both of the lower control arms.EXERCISE 4Translate the Chinese parts given in the brackets into English.1. All the suspension components (必必须处于良好的工作状态须处于良好的工作状态).2. The springs are a very important component of the suspension system that _ (提供行使舒适提供行使舒适).3. When the car meets a bump in the road, (弹簧靠压缩来吸收载量弹簧靠压缩来吸收载量).4. Coil springs compress and expand to (吸收车轮的动力吸收车轮的动力).5. Shock absorber is important (保保持轮胎与地面良好的接触持轮胎与地面良好的接触). Passage B Passage B Suspension Types A car usually has a different types of suspension on the front and back. One is a non-independent system, the left and right wheels being interlinked; another is an independent system, each wheel on the same axle moving vertically independently of each other. See figure 7-8. Figure 7-8 1. Live & Dead Axle 1. Live & Dead Axle SuspensionSuspension Basically, it is a rigid axle fixed between left and right wheels. The car body is suspended by leaf springs or coil springs on the axle unit. If the axle is the driving axle, it is called live axle. Live axle is very heavy . It consists of the differential, drive shafts and a strong tube enclosing all these things. Since the whole axle is rigidly fixed to the wheels instead of suspended by springs, the so-called un-sprung weight is very high. See figure 7-9. If the axle is not the driving axle, it is called dead axle. Without the driving mechanism incorporated, dead axle has much less un-sprung weight, so its ride quality is better than live axle. See figure 7-10. 2. MacPherson Strut 2. MacPherson Strut SuspensionSuspension The MacPherson strut is the most widely used front suspension system, which combines a shock absorber and a coil spring into a single unit. This provides a more compact and lighter suspension system that can be used for front-wheel drive vehicles. See figure 7-11. The shock absorber, strut, and spindle are a combined unit that is supported by the coil spring at the upper end and by the lower control arm at the bottom. A ball joint is attached to the lower part of the spindle. The lower arm is held in position by a sway bar and frame-mounted rod called a strut rod, or by a stabilizer bar that functions as a combined strut rod and sway bar. 3. Double Wishbones 3. Double Wishbones SuspensionSuspension To many suspension designers, double wishbones (or “A-arms”) suspension is the most ideal suspension. It can be used in front and rear wheels; it is independent and most important; and it has near perfect camber control. For 40 years and even today, this is the first choice for racing cars, sports cars and demanding sedans. See figure 7-12. Basically, double wishbones suspension always maintains the wheel perpendicular to the road surface, irrespective of the wheels movement. This ensures good handling. 4. Multi-link Suspension4. Multi-link Suspension Since the late 1980s, multi-link rear suspension is increasingly used in modern sedans and coupes. It is difficult to describe its construction because it is not strictly defined. In theory, any independent suspensions having 3 control arms or more are multi-link. Different designs may have very different geometry and characteristic, for example, BMWs multi-link looks like a letter “Z”, thus gave its name “Z-axle”. It is relatively space-engaging but offers very good handling; Honda Accords multi-link is essentially a double wishbones suspension added with the fifth control arm. Audi A4s Quadralink front suspension has four links. It looks alike double wishbones but eliminates torque steer. See figure 7-13.5. Torsion Beam Suspension5. Torsion Beam Suspension Most modern mini cars (for instance, VW Golf) employ torsion beam as the rear suspension. Compare with double wishbones, multi-link suspension engages little width of the car, thus enables greater rear seat room. It is cheaper too. Compare with MacPherson strut, its shock absorber is shorter and can be inclined steeply away from the vertical, thus engages less boot space. See figure 7-14. In fact, torsion beam suspension is only half-independent there is a torsion beam connecting both wheels together, which allows limited degree of freedom when forced. For some less demanding compact cars, this saves the anti-roll bars. On the contrary, it doesnt provide the same level of ride and handling as double wishbones or multi-link suspensions; although in reality it is superior to its only direct competitor, MacPherson strut. New Wordsinterlink int(:)lik v. 相互链接相互链接vertically v:tikli ad. 垂直地垂直地rigid ridVid a. 刚性的，不易弯的刚性的，不易弯的enclose inkluz v. 放入封套，括入放入封套，括入unsprung nspr a. 没有安装弹簧的没有安装弹簧的incorporated ink:preitid a. 合成一体的合成一体的camber kmb n. 弧形，眉形弧形，眉形v. 成弧形，使弯作弧形成弧形，使弯作弧形perpendicular p:pndikjul a. 垂直的，直垂直的，直立的立的irrespective 7irispektiv a. 不顾的不顾的，没关系的没关系的increasingly inkri:sili ad. 逐渐地逐渐地，渐增地渐增地coupe ku:pei n. 小轿车小轿车geometry imitri n. 几何，几何体几何，几何体eliminate ilimineit v. 除去，排除，剔除除去，排除，剔除demanding dim :ndi a. 要求高的，苛刻的要求高的，苛刻的superior sju:piri a. 上好的，出众的上好的，出众的competitor kmpetit n. 竞争者，竞争对手竞争者，竞争对手Phrases and Expressionsnon-independent system 非独立悬架系统非独立悬架系统independent system 独立悬架系统独立悬架系统live axle suspension 活轴悬架活轴悬架dead axle suspension 定轴悬架定轴悬架driving axle 驱动桥驱动桥unsprung weight 簧下重量，弹簧下重量簧下重量，弹簧下重量MacPherson strut suspension 麦弗逊滑柱式悬架麦弗逊滑柱式悬架ball joint 球窝接头，球头节，球形接头，球接球窝接头，球头节，球形接头，球接头头double wishbones suspension 双横臂悬架双横臂悬架multi-link suspension 多连杆式悬架多连杆式悬架torque steer 扭力转向扭力转向torsion beam suspension 扭矩梁式悬架扭矩梁式悬架perpendicular to 垂直于垂直于irrespective of 不论不论，不管不管superior to 比比优越优越（好好），），比比高级高级（好好）EXERCISE 5Abbreviations are very useful in practical work. Do you know the following English abbreviations you often come across in handling automotive materials? Read them and then translate them into corresponding Chinese terms.PartII Glance at the Structure PartII Glance at the Structure of the Automobileof the Automobile The following is the automobile battery and front frame of an automobile.Sample 1English TermsExplanationsChinese1. Automobile batteryGroup of similar elements that generates an electric chargeA. 汽车蓄电池2. Negative terminalPlace where a current-conducting wire, the cathode, is attachedB. 负极接线柱3. SeparatorPartition that separates the compartments of a batteryC. 隔板4. Plate and separatorThin, flat, rigid separator sheetD. 隔离板5. Battery caseCasing that protects the parts of a batteryE. 电池壳6. Positive terminalPlace where a current-conducting wire, the anode, is attachedF. 正极接线柱7. Vent capsRow of screwed-on cylindrical pieces that close the openings of a batteryG. 通气孔盖Sample 2English TermsExplanationsChinese1. Front frame of an automobileSet of metal parts forming the framework supporting the front wheelsH. 汽车前部框架结构2. Front frameThe front part of the frame of a carI. 前部框架结构3. BrakeMechanism used to slow or stop a carJ. 擦车闸4. Lower control armPart of the framework that gives flexibility to a carK. 下控制臂5. Rubber padElastic plate that absorbs shocksL. 橡胶垫EXERCISE 6EXERCISE 6The following are some Functions on Automobile. After reading them, you are required first to choose the interpretations given in Column C match the Functions given in Column A, and then put the best answer in Column B.ABC1. Automobile batteryA. 隔离板2. Negative terminalB. 正极接线柱3. SeparatorC. 前部框架结构4. Plates and separatorD. 汽车电池5. Battery caseE. 擦车闸6. Positive terminalF. 负极接线柱7. Vent capsG. 橡胶垫8. Front frame of an automobileH. 隔离物9. Front frameI. 通气孔盖10. BrakeJ. 电池壳11. Lower control armK. 下控制臂12. Rubber padL. 汽车前部框架结构EXERCISE 7The following are some expressions for the famous brands (England Motors Companies). Match the following brands in Column A with their Chinese equivalents in Column B. A BA.福登（福登（FODEN）B.迷你（迷你（MINI） C.阿斯奎斯（阿斯奎斯（ASQUITH）D.罗佛佛陆虎（虎（ALND ROVERE. 马柯斯（柯斯（MARCOS）F. 拉拉贡达（达（LAGONDA）G.罗佛（佛（ROVER）H. 戴姆勒（戴姆勒（DAIMLER） I. 奥斯奥斯顿马丁（丁（ASTON MARTIN）J. 麦克拉（麦克拉（MCLAREN） . PartIII Have a TryPartIII Have a Try Troubleshooting GuideEXERCISE 8 The part is to test your ability to organize the material in logical order.Symptom: Steering seems to be slipping. Description of problem: As you turn the wheel or hold it in a turned position, it feels like its slipping slightly back and forth. Probable Causes:Probable Causes:1.Low power steering fluid add fluid as needed. 2. Loose or worn power steering belt tighten or _ (maintain belt, replace belt). 3. Bad power steering pump have it checked for pressure and _ (adjust, replace) if needed. 4. Leaking power steering rack inspect _ (steering rack, steering belt) for leaks and replace rack if needed. 5. Broken steering rack mounts inspect _ (mounts, screws) for excessive play and repair as needed.PartIV Listening and PartIV Listening and SpeakingSpeaking In the Car LaboratorySample Dialogue 1A: Wow! What a big laboratory of your company! B: Yes, it is. A: What are these?B: They are automobile suspension components.A: Would you like to introduce something about it to me ?B: Yes, of course.A: What are they for?B: They are very important for a car. They can support the vehicle and provide ride comfort.A: I cant imagine they can do that! Sample Dialogue 2A: Hi, Wu Ming. What are you doing? B: Im doing an experiment. A: Whats that?B: It is suspension. My experiment is to find out its function to an automobile engine.A: I heard that suspension is the term given to the system of springs, shock absorbers and linkages.B: Yes. You see the suspension system connects a vehicle to its wheels.A: Anything else?B: Suspension systems serve dual purposes contributing to the cars handling and braking for good active safety and driving pleasure, and keeping vehicle occupants comfortable.A: It sounds interesting.B: The suspension also protects the vehicle itself and any cargo or luggage from damage and wear.A: Wow, thats great.