1、UUNITNIT 3 3 A AUTOMOBILEUTOMOBILE CHASSISCHASSIS汽车底盘汽车底盘授课教师：授课教师：LESSON1 THE CHASSIS STRUCTURE底盘构造底盘构造Learning Objectives（学习目标）（学习目标）Learn about the main systems of the chassis.Learn about the name and the function of the four main system.Learn about the key components of the chassis and can trans
2、late them into English.Grasp the special term and useful expressions about the chassis.PART ONE-STIMULATE STUDENTS INTEREST（激发兴趣）The following picture is the automobile chassis,which is made up of car frame,springs,shock absorbers,driving shaft,brakes,tires and wheels.Look at the picture and try to
3、introduce their position.PART TWO-STUDY PREPARATION（学习准备）1.New Words to learnchassis sis n.（车辆的）底盘;（飞机的）起落架;foundation faundein n.地基;基础;基金（会）;粉底;transmission trnsmn,trnz-n.播送;传送;传动装置;suspension sspenn n.悬浮;暂停;悬架;悬浮液;composition k:mpzn n.作文，作曲;创作;构图，布置;妥协，和解;propel prpel vt.推进;推动;驱动;驱使;forward f:wd a
4、dj.向前方的;迅速的;reverse riv:s vt.&vi.（使）反转;（使）颠倒;掉换，交换;clutch klt n.紧抓;控制;离合器;紧要关头;differential dfrenl n.机差速器;shock k n.震惊;振动;打击;vt.使休克;使震惊;使振动;使受电击;2.Phrase learning（短语学习）（短语学习）transmission system 传动系统driving system 行驶系统steering system 转向系统braking system 制动系统PART TWO-STUDY PREPARATION（学习准备）PART THREE-T
5、EXT(阅读资料)The Structure of the ChassisThe chassis is a very important part of the automobileAll other components and systems are attached to the chassisThe chassis of the automobile is the basic foundation of the vehicleIt includes the transmission system，driving system，steering system，and braking sy
6、stem(Fig.3-1)The transmission system is to transmit the power from the engine to the wheels to move the vehicleThis action will propel the vehicle in a forward or reverse directionThe main components of the transmission system are the clutch，transmission,differential,universal joint,half axle and dr
7、iving shaftPART THREE-TEXT(阅读资料)The driving system has three basic functions to receive power from driving shaft,to support gross vehicle weight and to ease the impact on car body on uneven roads so as to provide a comfortable driving environment for the passengers.The main components of the driving
8、 system are frame,axle,wheel,tires,shock absorbers,springs and suspension.The suspension system can absorb the road shockThis results in a smoother ride(because the car moves less)，safer handling(because the wheels stay on the road)and less mechanical wear(because the car is shaken about less)PART T
9、HREE-TEXT(阅读资料)The steering system is used to enable the driver to control the direction of the vehicle quickly and easily at all speedsThe steering system is designed to control the front wheels over all types of road conditions，through turns，and at different speedsMechanical and power steering uni
10、ts are usedThe automobile braking system is used to control the speed of the vehicleThe system must be designed to enable the vehicle to stop or slow down at the drivers commandPART THREE-TEXT(阅读资料)PART FOUR-DIALOGUE EXERCISE（对话练习）Situation:Some university students are having a tour in the plant of
11、SOUEAST.Richard：Hello，and welcome to SOUEASTIm Richard Li，the factory manager in charge of the plant youll be seeing todayWell，this way,pleaseLets start the tourJust feel free to ask me if you have any questionsLarry：Excuse me，MrLiShall we start with the chassis?Richard：Well，let me take this car as
12、an exampleAs you can see，chassis is made up of the transmission system，driving system,the steering system and the brake systemLarry：Thank youFrankly speaking，chassis seems to be a hard nut to crackCan we go along and get more about it?Richard：SureI know you have come a long way today,so I aim to mak
13、e your tour both interesting and worthwhileLarry：Shall we take a look at each part of the chassis?Richard：Id like to explain the functions of them one by oneFirst，we may start from the transmission systemAmy：Wow,I think I have acquired a lot todayWhat a special tour!How about you，Larry?Larry：Me tooI
14、 do have learned a lot in the tour todayI think it will be quite helpful to my paperThank you very much for your patience and kindness，MrLiRichard：You are welcomeWhy dont we talk over a cup of coffee in my office?Id love to give you our workshop manualIt may be helpful to youLarry：WonderfulHow nice
15、you are!PART FOUR-DIALOGUE EXERCISE（对话练习）PART FIVE-NOTES TO THE TEXT(难点解析)1.The chassis of the automobile is the basic foundation of the vehicleIt includes the transmission system，driving system，steering system，and braking systems汽车底盘是车辆的基体。它包括传动系统，行驶系统，转向系统和制动系统。2.The main components of the transmi
16、ssion system are the clutch，transmission，differential,universal joint,half axle and driving shaft传动系统的主要部件有离合器、变速器、差速器、万向节、半轴和传动轴。3.The steering system is designed to control the front wheels over all types of road conditions，through turns，and at different speedsMechanical and power steering units a
17、re used转向系统被设计为可以控制前轮在各种路面条件和不同转速下通过弯路。机械和动力转向装置都有应用。LESSON2 THE TRANSMISSION SYSTEM 传动系统传动系统Learning Objectives（学习目标）（学习目标）Learn about the key components of the transmission system.Learn about the function of the transmission system.Learn about structure of the transmission system.Grasp the new wor
18、ds and useful expressions about the transmission system.PART ONE-STIMULATE STUDENTS INTEREST（激发兴趣）The following picture is the transmission system.Work with your classmates and try to write out their English names.PART TWO-STUDY PREPARATION（学习准备）1.New Words to learnhydraulic haidrlik adj.水力的，水压的;用水发
19、动的;mechanical miknikl adj.机械的，机械学的;手工操作的;automatic tmtk adj.自动的;n.自动化机器或设备;自动手枪;manual mnjul adj.用手的;手制的，手工的;法占有的;体力的;progressive prresv adj.不断前进的;进步的;进行的;torque t:k n.（尤指机器的）扭转力;转（力）矩;reverse rv:s vt.&vi.（使）反转;（使）颠倒;掉换，交换;neutral nu:trl n.（汽车或其他机器的）空挡位置;inner n adj.内部的，内心的;精神的;秘密的;n.内部，里面;primary p
20、ramri adj.首要的，主要的;motion mun n.运动;手势;动机，意向;请求;uphill p hil adj.上坡的，向上的;费力的，辛苦的，艰难的;位于高处的;adv.上山地，上坡地;n.登高，上坡;stretch stret v.伸展;延伸;持续;包括;n.伸展;弹性;一片;一段时间;adj.可伸缩的;弹性的;frequently frikwntli adv.频繁地，屡次地;往往;动;动辄;enclose inkluz vt.（用墙、篱笆等）把围起来;把装入信封;附入;pinion pinjn n.活塞;thrust rst vt.&vi.插入;逼迫;强行推入;延伸;PAR
21、T TWO-STUDY PREPARATION（学习准备）2.Phrase learning（短语学习）（短语学习）universal joint gear 万向传动装置driving axle 驱动桥propeller shaft 传动轴universal joint 万向节axle housing 桥壳axle shaft 半轴final drive 主减速器thrust washers 止推垫圈PART TWO-STUDY PREPARATION（学习准备）PART THREE-TEXT(阅读资料)Most transmission system use manual or hydrau
22、lic transmission.In different cars,the composition of the transmission system is slightly different.It is mainly composed of clutch,manual transmission,universal-joint transmission device,drive axles,final drive and differential.More and more modern cars are equipped with automatic transmission to r
23、eplace the manual transmission and the clutch.The clutch is designed to disconnect drive from the engine to transmission and to allow a smooth，progressive take-up of drive The clutch(Fig.3-2)includes a flywheel,a pressure plate,a clutch disk and so on.When the driver pushes down on the clutch pedal,
24、the engine and the transmission are disconnected so the engine can run even if the car is standing still.Then,the engine runs without transmitting power to the transmission system.When you release the clutch pedal,the engine and the input shaft are directly connected to one another.PART THREE-TEXT(阅
25、读资料)The purpose of the transmission is to change the torque applied to the driving wheels for different road conditionsIn addition，the transmission is used to reverse the vehicle direction and provide neutral(no power)to the wheelsA transmissions primary job is to allow the engine to operate in its
26、narrow range of speeds while providing a wide range of output speeds(Fig.3-3).A higher torque should be applied to the wheels to set an automobile in motion or move uphill with a full load than to keep it rolling after it gets under way on level stretches of the road.To meet these variable torque re
27、quirements,special gear boxes are used.PART THREE-TEXT(阅读资料)Transmission is designed for changing the torque transmitted from the engine crankshaft to the propeller shaft,reversing the vehicle movement and disengaging the engine from the drive line for a long time at parking or coasting.PART THREE-T
28、EXT(阅读资料)Universal joint gears are used to transfer power from one turning shaft to another whose angle and position change frequently.The basic universal joint gear consists of universal joints,driveshafts and a center bearing(Fig.3-4).PART THREE-TEXT(阅读资料)Driving axle assembly enclose the final dr
29、ive gears,differential gears and axle shaft in one housing.The function of the driving axle assemblies is to decrease the speed and increase torque that comes from the universal joint,then distribute the power to the drive wheels.The typical final drive assembly consists of a crown wheel and a pinio
30、n.While final drive components must be held firmly in position by bearings and thrust washers,there must be operational clearance between meshing components.PART THREE-TEXT(阅读资料)The final drive is to turn the drive through 90。and reduce the speed of the driveThe differential is designed to allow the
31、 inner driving road wheel to rotate slower than the outer wheel when the automobile is corneringWhile it ensures that a drive is applied equally to both wheels.Differentials are typically composed of a gear mechanism in which a ring gear receives input power,which is transferred to two side gears by
32、 means of usually two opposing central pinion gears on a common shaft(Fig.3-5).PART THREE-TEXT(阅读资料)PART FOUR-DIALOGUE EXERCISE（对话练习）Situation:The following dialogue is between a customer and a salesman.Read it aloud and try to discuss with your partner on the new safety devices youve ever heard ofC
33、ustomer：I like the Golf you showed me beforeI think its more practical for my needsSalesman：Alright，sirYou are making a good choiceVolkswagon has made a lot of design improvements in the new Golf.Customer：What kind of standard does it come with?Salesman：On all our new cars，the standards include：7-sp
34、eed DSG，TSI engine，ESP,anti-skid system，parking sensor,on-board navigation DVD，6-airbag SRS，12-way adjustable seat，anti-dazzle rear view mirror and so onCustomer：DSG?TSI?ESP?Can you explain them?Salesman：They are the abbreviationDSG is for Direct Shift Transmission，or Double Clutch Transmission；TSI
35、for Turbo-Super charging Injection；and ESP for Electronic Stability ProgramAll are made for safer drivingCustomer：Thank you for your introductionAnother important question is the time I can get this carI need a new car rather soonSalesman：Well，I Can say that the new models will be here next monthPAR
36、T FOUR-DIALOGUE EXERCISE（对话练习）PART FIVE-NOTES TO THE TEXT(难点解析)1.A higher torque should be applied to the wheels to set an automobile in motion or move uphill with a full load than to keep it rolling after it gets under way on level stretches of the road.与在水平良好路面上行驶相比，汽车满载运行或者爬坡的时候需要给车轮加载更高的扭矩。The f
37、unction of the driving axle assemblies is to decrease the speed and increase torque that comes from the universal joint,then distribute the power to the drive wheels.驱动桥总成的作用是减低速度，增大从万向节传来的转矩，并向驱动轮传输动力。LESSON3 SUSPENSION悬架悬架Learning Objectives（学习目标）（学习目标）Learn about the function of the suspension.Le
38、arn about the main components of the suspension.Learn about the terms about the suspension.Grasp the new words and useful expressions about the suspension.PART ONE-STIMULATE STUDENTS INTEREST（激发兴趣）The following picture is the world-famous Mc.Pherson suspension.Work with your classmates and try to wr
39、ite out their English names.PART TWO-STUDY PREPARATION（学习准备）1.New Words to learnframe freim n.框架;眼镜框;组织;边框;comfort kmft n.安慰;舒适;使人舒服的事物;ease i:z n.轻松，舒适;容易;安逸;不拘束，自在;vt.解除痛苦;减轻;延缓;松弛;absolutely bslutli,bslutli adv.绝对地;完全地;毫无疑问地;essential senl adj.基本的;必要的;本质的;n.必需品;基本要素;occupant :kjupnt n.占有人;居住者;pri
40、nciple prnspl n.原则，原理;准则，道义;道德标准;本能;solid s:lid adj.实心的;结实的，可靠的;可信赖的;independent indipendent adj.独立的；自主的;deliver dliv vt.发表;递送;交付;使分娩;vi.投递;传送;characteristic krktristik adj.特有的;独特的;n.特性，特征，特色 tire ta n.轮胎;头饰;wheel wi:l n.轮子;旋转;store st:v.贮存;（在计算机里）存储;shock k n.休克;震惊;振动;打击;vt.使休克;使震惊;bump bmp vt.&vi.
41、碰撞，冲撞;颠簸;dip dip vt.&vi.（使）微降，（使）下沉;（使）向下再向上;crack krk vt.破裂，打开;vi.断裂，折断;碎裂声，爆裂声;PART TWO-STUDY PREPARATION（学习准备）dampen dmpn vt.抑制;使潮湿;使沮丧;隔音，防音;thermal :ml adj.热的，保热的;温热的;oscillation :silein n.振动;动摇;波动;2.Phrase learning（短语学习）（短语学习）shock absorber 减振器torsion bar 扭杆弹簧leaf spring 钢板弹簧independent suspen
42、sion 独立悬架PART TWO-STUDY PREPARATION（学习准备）PART THREE-TEXT(阅读资料)The suspension systemThe suspension system on the automobile includes such components as the springs，shock absorbers，torsion bars，axles，and connecting linkagesThese components are designed to support the body and frame，the engine，and the
43、transmission system on the roadWithout the suspension system，the comfort and ease of driving of the vehicle would be reducedThe suspension system，while not absolutely essential to the operation of a motor vehicle，makes a big difference in the amount of pleasure experienced while drivingEspecially,it
44、 acts as a bridge between the occupants of the vehicle and the road they ride onThe suspension contains two major parts:front suspension and rear suspension.The front suspension(Fig.3-6)allows the front wheels to move up and down and absorb road shocks.And it also allows the front wheels to swing fr
45、om side to side so that the car can be steered.PART THREE-TEXT(阅读资料)The rear suspension(Fig.3-7)uses leaf springs,arranged at one wheel.The leaf spring is anchored at three places:the front hanger,the rear shackle and the axle housing.PART THREE-TEXT(阅读资料)As the suspension system，it has two basic pr
46、inciples of design：solid axle(see fig.3-8)and independent suspension(see fig.3-9)In solid axle suspension，because both wheels share the same axle，the up or down movement of one wheel causes a same movement in the other wheelThey respond as one unitAs you can imagine，this doesnt make for the most com
47、fortable ride PART THREE-TEXT(阅读资料)The other main design is called independent suspensionAs the name suggests，independent suspension assemblies offer a separate“bridge”for each wheelThey deliver the best ride characteristics by far,and are found most frequently in passenger cars，minivans，and other s
48、treet vehiclesThis is the most popular kind of suspension system in use todayIf you like the“smoothness”of your cars ride，we can almost guarantee it has independent suspension PART THREE-TEXT(阅读资料)In addition to axles，wheels and tires，todays suspension systems utilize two other components that are c
49、ritical to safe and comfortable driving：springs and shock absorbers(see fig.3-9)A Cars springs are the central part of the suspensionSprings absorb and store road shock caused by bumps，dips，cracks，and so onThey absorb this shock by either compressing or extendingPART THREE-TEXT(阅读资料)The other main p
50、art of a cars suspension is the shock absorber.Contrary to its name,a shock absorber plays a minimal role in absorbing impacts taken by the suspensionThats the springs jobA shock absorber dampens road impacts by converting the up and down oscillations of the spring into thermal energy PART THREE-TEX
