汽车专业英语3781451152讲课讲稿

1、汽车专业英语3781451152 Unit 1 Unit 1 Engine Mechanical Engine Mechanical n1. Cylinder Block1. Cylinder Block nThe The engine blockengine block is the main supporting is the main supporting structure to which all other engine parts are structure to which all other engine parts are attached. Fig. 1-1-1 show

2、s a attached. Fig. 1-1-1 shows a cylindercylinder block. block. It has two main sections: the cylinder It has two main sections: the cylinder section and the section and the crankcasecrankcase section. The section. The crankcase section is used to crankcase section is used to househouse the the cran

3、kshaftcrankshaft, , oiloil pan.pan. Cooling passageways are Cooling passageways are built within the block. These passageways, built within the block. These passageways, also known as also known as water socketswater sockets, surround the , surround the cylinders. They allow cylinders. They allow co

4、olantcoolant to circulate to circulate throughout the cylinder area to keep the throughout the cylinder area to keep the engine cool. There is also a drilled engine cool. There is also a drilled passageway within some blocks for the passageway within some blocks for the camshaftcamshaft. Many oil ho

5、les are drilled . Many oil holes are drilled internallyinternally so that engine parts can be so that engine parts can be adequatelyadequately lubricatedlubricated. .engine engine 发动机发动机 block block 气缸体气缸体cylinder cylinder 气缸气缸crankcase crankcase 曲轴箱曲轴箱house house 安装安装crankshaft crankshaft 曲轴曲轴camsh

6、aft camshaft 凸轮轴凸轮轴coolant coolant 冷却液冷却液oil pan oil pan 机油盘机油盘water socket water socket 水套水套internally internally 内部地内部地adequatelyadequately 充分地充分地lubricate lubricate 润滑润滑 Four-Cylinder Engine Cylinder Block Four-Cylinder Engine Cylinder Block ( (四缸发动机气缸体四缸发动机气缸体) ) Fig. 1-1-1Fig. 1-1-1 1- cylinder

7、 block 1- cylinder block ( (气缸体气缸体) ) 2- cylinder 2- cylinder ( (气缸气缸) ) 3- crankcase area 3- crankcase area （曲轴箱部分）（曲轴箱部分）n2. Cylinder Liners2. Cylinder LinersnThe purpose of using a The purpose of using a linerliner is that, if is that, if the cylinder is damaged, the liner can be the cylinder is

8、damaged, the liner can be removeremoved and d and replacereplaced rather easily. There d rather easily. There nare two types of sleevesare two types of sleeveswet and dry.wet and dry.n SealSeals must be used on the top and bottom s must be used on the top and bottom of the wet sleeve in order to kee

9、p the of the wet sleeve in order to keep the coolant from coolant from leakleaking out of the cooling ing out of the cooling system. system. n3. Cylinder Head3. Cylinder HeadnThe Cylinder head is used to hold the The Cylinder head is used to hold the valvevalves, and it has s, and it has portports t

10、o allow air, s to allow air, fuel and fuel and exhaustexhaust to move through the to move through the engine. engine. In additionIn addition, it has coolant , it has coolant passages. Fig.1-1-2 shows a cylinder head. passages. Fig.1-1-2 shows a cylinder head. After the cylinder head has been cast, A

11、fter the cylinder head has been cast, some areas must be machined so that some areas must be machined so that intakeintake and exhaust and exhaust manifoldmanifolds can be s can be attached, valves can be seated, attached, valves can be seated, sparkspark plugplugs and s and injectorinjectors can be

12、 s can be installinstalled, and ed, and a good seal can be provided to the block.a good seal can be provided to the block.linerliner（发动机)气缸套remove remove 拆下replace replace 取代seal seal 密封，封条leak leak 使渗漏valve valve 气门；阀port port 孔管道exhaust exhaust 排气in addition in addition 另外intake intake 进气，吸入manifo

13、ld manifold 歧管spark spark 火花plug plug 塞子injector injector 喷油器install install 安装 Cylinder HeadCylinder Head（气缸盖）（气缸盖） Fig. 1-1-2Fig. 1-1-21-cap(1-cap(盖盖) 2- cylinder head ) 2- cylinder head boltbolt（气缸盖螺栓）（气缸盖螺栓） 3-exhaust manifold gasket3-exhaust manifold gasket（排气歧管垫）（排气歧管垫）4-cylinder head gasket4-

14、cylinder head gasket（气缸（气缸盖垫片）盖垫片）5- intake manifold 5- intake manifold gasket(gasket(进气歧管垫进气歧管垫) ) 6-cylinder head (6-cylinder head (气缸盖气缸盖) )7-cylinder head cover gasket 7-cylinder head cover gasket ( (气缸盖罩垫片气缸盖罩垫片)8- cylinder )8- cylinder head cover (head cover (气缸盖罩）气缸盖罩）n4. Piston and Connectin

15、g Rod Assembly4. Piston and Connecting Rod AssemblynThe The pistonpiston and and connecting rodconnecting rod assembly assembly transmits the power from transmits the power from combustioncombustion to to the crankshaft. Shown in Fig.1-1-3 ,it the crankshaft. Shown in Fig.1-1-3 ,it mainlymainlyn con

16、sists ofconsists of piston, piston, compressioncompression rings, rings, oil control rings, piston oil control rings, piston pin pin and and connecting rod.(1)piston: Piston connecting rod.(1)piston: Piston fitfits s closelyclosely within the engine cylinder or within the engine cylinder or liner an

17、d is able to move liner and is able to move alternatelyalternately up up and downand down in the cylinder.(2)piston rings: in the cylinder.(2)piston rings: There are two types of piston ringsThere are two types of piston rings：compression and oil control rings. The compression and oil control rings.

18、 The compression ringscompression rings are used to seal the are used to seal the pressures of compression and power. The pressures of compression and power. The oil control rings are employed to oil control rings are employed to scrapescrape oil from the cylinder walls.(3)oil from the cylinder wall

19、s.(3)piston piston pinpin: It is used to connect piston to : It is used to connect piston to connecting rod.(4)connecting rod: it is connecting rod.(4)connecting rod: it is used to connect piston to crankshaft and used to connect piston to crankshaft and changes the changes the reciprocatingreciproc

20、ating motionmotion to the to the rotaryrotary motion. motion. piston piston 活塞connecting rod connecting rod 连杆combustion combustion 燃烧consists ofconsists of 由.组成compression compression 压缩pin pin 销fit fit 使配合closely closely 紧密地alternately alternately 交替地up and down up and down 上上下下compression ring co

21、mpression ring 气环scrape scrape 把.刮除piston pinpiston pin 活塞销reciprocating motionreciprocating motion 往复运动rotary rotary 旋转的 Piston and Rod Assembly Piston and Rod Assembly （活塞和连杆总成）（活塞和连杆总成） Fig. 1-1-3Fig. 1-1-3 1- piston (1- piston (活塞活塞) ) 2- piston rings (2- piston rings (活塞环活塞环) )3- piston pin(3-

22、piston pin(活塞销活塞销) ) 4- connecting rod (4- connecting rod (连杆连杆) ) 5- connecting rod bolts 5- connecting rod bolts ( (连杆螺栓连杆螺栓) ) 6- connecting rod cap 6- connecting rod cap ( (连杆盖连杆盖) ) 7- connecting rod 7- connecting rod bearing (bearing (连杆轴瓦连杆轴瓦) )5. Crankshaft Assembly5. Crankshaft AssemblyIt i

23、s bolted to the bottom of theIt is bolted to the bottom of thecylinder block. The crankshaftcylinder block. The crankshaftassembly includes the crankshaft,assembly includes the crankshaft,bearings, flywheel, bearings, flywheel, harmonicharmonicbalancerbalancer, , timingtiming geargear, and front , a

24、nd front and rear seals.Fig.1-1-4 shows and rear seals.Fig.1-1-4 shows crankshaft assembly.crankshaft assembly.6. Camshaft Assembly6. Camshaft AssemblyThe camshaft is driven by the The camshaft is driven by the crankshaft and used to open and crankshaft and used to open and close the valves. The cam

25、shaft close the valves. The camshaft assembly includes the camshaft, assembly includes the camshaft, camshaft timing gear, camshaft camshaft timing gear, camshaft bearing, and timing bearing, and timing chain, beltchain, belt（if usedif used）. .harmonicharmonicbalancerbalancer 扭转减震器timingtiming gear

26、gear 正时齿轮chain beltchain belt 链(条)传动带7. Valve Drive Mechanism7. Valve Drive MechanismIt is used to transfer the camshaft lift It is used to transfer the camshaft lift The valve drive mechanism consists of theThe valve drive mechanism consists of thelifterlifters, the s, the pushrodpushrods and the s

27、 and the rocker armsrocker armsLifters change the rotary motion of the Lifters change the rotary motion of the camshaft to reciprocating motion to open camshaft to reciprocating motion to open and close the valve. and close the valve. HydraulicHydraulic lifters lifters are used to reduce noise and c

28、ontrol are used to reduce noise and control the valve clearance on many engines. Theythe valve clearance on many engines. Theyabsorb the valve train absorb the valve train clearanceclearance by using by usingoil pressure inside the lifter body. oil pressure inside the lifter body. Pushrods are used

29、only on engines thatPushrods are used only on engines thathave the camshaft placed within the block.have the camshaft placed within the block.Overhead camshafts do not need pushrods.Overhead camshafts do not need pushrods.Rocker arms are designed to change the Rocker arms are designed to change the

30、direction of the cam direction of the cam lifting forcelifting force. . lifter n. lifter n. 挺柱pushrod n.pushrod n. 推杆rocker armrocker arm 摇臂hydraulic hydraulic adj. adj. 液压的clearance clearance n. n.间隙lifting lifting forceforce 举升力 Crankshaft AssemblyCrankshaft Assembly（曲轴总成）（曲轴总成）n Fig. 1-1-4Fig. 1-

31、1-4n1- front (1- front (前端前端) 2- main bearing) 2- main bearing（主轴颈）（主轴颈）n3- connecting rod bearing 3- connecting rod bearing （连杆轴颈）（连杆轴颈）n4-crank4-crank（曲柄）（曲柄） 5- counterweight5- counterweight（平衡重）（平衡重）n6- rear flange6- rear flange（后端法兰）（后端法兰）n7- camshaft assembly 7- camshaft assembly （凸轮轴总成）（凸轮轴总成

32、）n8. Valve Assembly8. Valve AssemblynThe valve assembly, shown in Fig.1-1-5, The valve assembly, shown in Fig.1-1-5, includes the valves, includes the valves, valve guidesvalve guides, , valvevalvenseatsseats, valve springs, , valve springs, spring retainersspring retainers and and seals.seals. (1)v

33、alves:The intake valves and the (1)valves:The intake valves and the exhaust valves are located within the cylinder exhaust valves are located within the cylinder head on most engines today. The exhaust valves head on most engines today. The exhaust valves are usually smaller in are usually smaller i

34、n diameterdiameter than the than the intake ones, because on the exhaust stroke the intake ones, because on the exhaust stroke the gases move more easily for the pressure of the gases move more easily for the pressure of the piston forcing them out.(2) valve guides: The piston forcing them out.(2) v

35、alve guides: The valve guides support the valve in the cylinder valve guides support the valve in the cylinder head.(3) valve seats :The seats provide a head.(3) valve seats :The seats provide a surface for the intake and exhaust valves to surface for the intake and exhaust valves to seal the seal t

36、he combustion chambercombustion chamber. They are pressed . They are pressed into the cylinder head and into the cylinder head and ground ground to the to the correct angle.(4) valve springs, correct angle.(4) valve springs, keeperkeepers and s and retainers: The valve springs keep the valves retain

37、ers: The valve springs keep the valves closed when the camshaft is not lifting the closed when the camshaft is not lifting the valves. Keepers and retainers are designed to valves. Keepers and retainers are designed to keep the valve spring keep the valve spring securesecured to the valve d to the v

38、alve stemstem. . valve guide valve guide 气门导管valve seatvalve seat 气门座spring spring retainer retainer 弹簧座圈diameter diameter 直径combustion combustion chamberchamber 燃烧室ground.ground. 与水平面成keeper keeper 锁片secure secure 紧固stem stem 杆，柄Translation Skill (1)Translation Skill (1) 科技英语翻译的标准与方法科技英语翻译的标准与方法一、翻

39、译的标准一、翻译的标准科技英语的翻译标准可概括为科技英语的翻译标准可概括为“忠实、通顺忠实、通顺”四个字。四个字。忠实，指忠实于原文内容。忠实，指忠实于原文内容。通顺，指译文语言必须通俗易懂，符合规范。通顺，指译文语言必须通俗易懂，符合规范。例如：例如：1. The electric resistance is measured in ohms. 误译：电的反抗是用欧姆测量的。误译：电的反抗是用欧姆测量的。 正译：电阻的测量单位是欧姆。正译：电阻的测量单位是欧姆。 2. The moment the circuit is completed, a current will start flow

40、ing the coil. 误译：电路被完成的片刻，一个电流将开始流向这个线误译：电路被完成的片刻，一个电流将开始流向这个线 圈。圈。 正译：电路一旦接通，电流开始流向线圈。正译：电路一旦接通，电流开始流向线圈。二、翻译的方法二、翻译的方法翻译的方法一般来说有直译（翻译的方法一般来说有直译（literal translation）和异译（）和异译（free translation）两种。）两种。直译，指直译，指“既忠实于原文内容，又忠实于原文的形式既忠实于原文内容，又忠实于原文的形式”的翻译。的翻译。异译，指忠实于原文的内容，但不拘泥原文的形式。异译，指忠实于原文的内容，但不拘泥原文的形式。例

41、如：例如： Many oil holes are drilled internally so that engine parts can be adequately lubricated. 直译：有许多油孔在内部被钻出，以使发动机能够被充分的直译：有许多油孔在内部被钻出，以使发动机能够被充分的 润滑。润滑。 异译：发动机内部钻有许多油道，可使其得到充分的润滑。异译：发动机内部钻有许多油道，可使其得到充分的润滑。 ExercisesExercises（练习）（练习）1.Translate the following into Chinese1.Translate the following in

42、to Chinese（1 1）valve spring retainervalve spring retainer（2 2）valve drive mechanismvalve drive mechanism（3 3）exhaust manifold gasketexhaust manifold gasket（4 4）valve stemvalve stem（5 5）reciprocating enginereciprocating engine（6 6）compression ratiocompression ratio（7 7）exhaust strokeexhaust stroke（8

43、8）connecting rodconnecting rod bearingbearingn（1）气门弹簧座圈）气门弹簧座圈（2）气门驱动装置）气门驱动装置（3）排气歧管垫）排气歧管垫（4）气门杆）气门杆（5）往复式发动机）往复式发动机（6）压缩比）压缩比（7）排气行程）排气行程（8）连杆轴承）连杆轴承2.Translate the following into English2.Translate the following into English（1 1）曲轴主轴径）曲轴主轴径（2 2）缸盖螺栓）缸盖螺栓（3 3）活塞环）活塞环（4 4）连杆轴径）连杆轴径（5 5）气缸盖垫）气缸盖垫（6

44、 6）连杆螺栓）连杆螺栓（7 7）摇臂轴）摇臂轴 (8)(8)液力挺柱液力挺柱（1 1）Crankshaft main bearingCrankshaft main bearing（2 2）Cylinder head boltCylinder head bolt（3 3）Piston ring Piston ring （4 4）Connecting rod bearing Connecting rod bearing （5 5）Cylinder head gasketCylinder head gasket（6 6）Connecting rod boltConnecting rod bolt（

45、7 7）Rocker arm shaftRocker arm shaft（8 8）Hydraulic lifterHydraulic lifter3.Translate the following sentences into English3.Translate the following sentences into English(1).The problem can often be(1).The problem can often be associated with a crack in associated with a crack in cylinder head or pos

46、sible warp of cylinder head or possible warp of the cylinder head .A crack in the the cylinder head .A crack in the block may also cause coolant to block may also cause coolant to the combustion chamber and cause the combustion chamber and cause white exhaust smoke. white exhaust smoke.(2).When inst

47、alling an exchange (2).When installing an exchange cylinder head (with camshaft cylinder head (with camshaft installed )the contact surfaces installed )the contact surfaces between the hydraulic lifters and between the hydraulic lifters and the cam must be oiled before the cam must be oiled before installing the cylinder head over. installing the cylinder head over