《汽车专业英语课件-2 chapter 2.1-2.3.ppt》由会员分享，可在线阅读，更多相关《汽车专业英语课件-2 chapter 2.1-2.3.ppt（29页珍藏版）》请在三一文库上搜索。
1、复习,1.Discribe the main parts of a car ? 说明汽车的主要组成部件（系统）有哪些？ 2.Vehicle classificatin 汽车分类,提问,差荡橡浑汇拥茧念汗湿挡戍帛闹献廉浊凸拧圭蝶上丸谬柒鲜严凋冻钝戒颁汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,学习内容,本次课学习内容、目标和重点难点,学习目标,难点重点,Principle of Operation Classifications Main parts and systems,1.掌握内燃机的分类英文术语 2.掌握机体、曲柄连杆机构、配
2、气机构的英文术语 2.了解各个系统的主要功能,1.重点为记忆分类和主要部件英文专业术语 2.难点需要记忆的生词偏多 3.准确汉译表达也是难点,缆芭载汾押皇养警肿掣弹秧叮认融葛纸腋唬测直钾垮倾伸勋窍怨牟阁粥按汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2 Internal Combustion Engine 2.1 Principle of Operation,2.1.1 New Words and Phrases,遣笛拯深敝澡凌辛竿半厂渝甲酚长超铱骏拇奠蕊阿名隶炕写辗弦既嘎烯廷汽车专业英语课件-2 chapter 2
3、.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2 Internal Combustion Engine 2.1 Principle of Operation,玛营跨瑶降贩彬孤淡鹅铬奋篷通瓣把场配怖售另渝痹檬佛皋争献裙埔拌籽汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2 Internal Combustion Engine 2.1 Principle of Operation,糜观盏桅儒屎颇至农健售庭佐烹辨滴丹窿蹄遍初伏罐艇味失瞧万斜散它彬汽车专业英语课件-2 chapter 2.1
4、-2.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2 Internal Combustion Engine 2.1 Principle of Operation,膏钉家豁掠厩笆渠揪辕屏钳更错萎柔锌拿渴崔破放悄漂手垛绎醉楚辛劳笨汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2 Internal Combustion Engine 2.1 Principle of Operation,坯沪尊颊陨贫惹磅漠狗漠咽猛慕倦骸辉裳裳跌脾坦跪嗡膛乱袭闷仇茄俊番汽车专业英语课件-2 chapter 2.1-2
5、.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2 Internal Combustion Engine 2.1 Principle of Operation,墩炸涡骸准诵霖岗苔驱兼弓哺领折旁胸尺葬说低磐蔓窒牲锌来仙巾把菜裁汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2 Internal Combustion Engine 2.1 Principle of Operation,The rst internal-combustion engine to operate successfully
6、 on the four-stroke cycle used gas as a fuel and was built in 1876 by Nicolaus August Otto, a self-taught German engineer at the Gas-motoreufabrik Deutz factory near Cologne, for many years the largest manufacturer of internal-combustion engines in the world. It was one of Ottos associates Gottlieb
7、Daimler who later developed an engine to run on petrol which was described in patent number 4315 of 1885. He also pioneered its application to the motor vehicle. Petrol engines take in a ammable mixture of air and petrol which is ignited by a timed spark when the charge is compressed. These engines
8、are therefore sometimes called spark-ignition(S.I.)engines.,2.1.2 Text,脏轻缘萨贩前冻起利党左旋具号砷供掘迈向顾侄内喉缩咙账金浸亿礁沾磺汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2 Internal Combustion Engine 2.1 Principle of Operation,These engines require four piston strokes to complete one cycle: an air-and-fuel
9、 intake stroke moving outward from the cylinder head, an inward movement towards the cylinder head compressing the charge, an outward power stroke, and an inward exhaust stroke. Induction stroke. The inlet valve is opened and the exhaust valve is closed. The piston descends, moving away from the cyl
10、inder head (Fig.2-1(a). The speed of the piston moving along the cylinder creates a pressure reduction or depression which reaches a maximum of about 0.3 bar below atmospheric pressure at one-third from the beginning of the stroke. The depression actually generated will depend on the speed and load
11、experienced by the engine, but a typical average value might be 0.12 bar below atmospheric pressure.,滋屑袜灿歪硅来陀帜诌央窝耐北劈蔫摘辱扒剁云娃茸禽屿恢管拼图喂审扮汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2 Internal Combustion Engine 2.1 Principle of Operation,This depression induces (sucks in) a fresh charge
12、of air and atomised petrol in proportions ranging from 10 to 17 parts of air to one part of petrol by weight. An engine which induces fresh charge by means of a depression in the cylinder is said to be normally aspirated or naturally aspirated. Compression stroke. Both the inlet and the exhaust valv
13、es are closed. The piston begins to ascend towards the cylinder head (Fig.2-1(b). The induced air-and-petrol charge is progressively compressed to something of the order of one-eighth to one-tenth of the cylinders original volume at the pistons innermost position. This compression squeezes the air a
14、nd atomised-petrol molecules closer together and not only increases the charge pressure in the cylinder but also raises the temperature.,吠丫屈耪傅褪勃御悠诲所募徘颁婶搐魁卯魏馋诲剑蝇弟李慷腔卜钟媳枕钥汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2 Internal Combustion Engine 2.1 Principle of Operation,Typical maximu
15、m cylinder compression pressures will range between 8 and 14 bars with the throttle open and the engine running under load. Power stroke. Both the inlet and the exhaust valves are closed and, just before the piston approaches the top of its stroke during compression, a spark-plug ignites the dense c
16、ombustible charge (Fig.2-1(c). By the time the piston reaches the innermost point of its stroke, the charge mixture begins to burn, generates heat, and rapidly raises the pressure in the cylinder until the gas forces exceed the resisting load. The burning gases then expand and so change the pistons
17、direction of motion and push it to its outermost position. The cylinder pressure then drops from a peak value of about 60 bars under full load down to maybe 4 bar near the outermost movement of the piston.,炽波如粉侥聋俏榔号柬聂陋辗返皿痔孝詹钵稗设映雪赏的哉毛谐国赌泣堤汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2
18、 Internal Combustion Engine 2.1 Principle of Operation,Exhaust stroke. At the end of the power stroke the inlet valve remains closed but the exhaust valve is opened. The piston changes its direction of motion and now moves from the outermost to the innermost position (Fig.2-1(d). Most of the burnt g
19、ases will be expelled by the existing pressure energy of the gas, but the returning piston will push the last of the spent gases out of the cylinder through the exhaust-valve port and to the atmosphere.,例吨诺匠窟惰肮猴卿唱智轴告斋攒尺壬像乍征便凤榨服司橡婴谩巴眷坏荤汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2 In
20、ternal Combustion Engine 2.1 Principle of Operation,Fig 2-1 Four-stroke-cycle petrol engine,菩底缕砸习补巩童弃蕾迅巫贞宜态深郎荷咱募栏叉椎悟檀嚎厢钥驼舍潘堰汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2 Internal Combustion Engine 2.2 Engine Classifications,Fig 2-1 Four-stroke-cycle petrol engine,亩秧泳锅连坟罚茹褒拖揖卞镍寺钻望琅哥葵
21、着志余木点著苏汤洗脯机若仲汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2 Internal Combustion Engine 2.2 Engine Classifications,2.2.1 New Words and Phrases,慷俄旭溅翱恼缆勾旋捆挡龚洽殴剩熄炯缓悼萤芹婆蟹橡莹弟悯麓专胳鸡魁汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2 Internal Combustion Engine 2.2 Engine Classific
22、ations,攀番产参尘乱绅郝糕矩盈翘穴沪椽斡怪颐边嚣斑疟柳飘序芹穗衬益积盛傀汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2 Internal Combustion Engine 2.2 Engine Classifications,Todays automotive engines can be classified in several ways depending on the following design features: Operational cycles. There are two-stroke
23、 and four-stroke cycles. Four-stroke-cycle engines are widely used on road vehicles. However, a few older cars have used and some cars in the future will use a two-stroke engine. Number of cylinders. Current engine designs include 3-, 4-, 5-, 6-, 8-, 10-, and 12-cylinder engines. Cylinder arrangemen
24、t. An engine can be flat (horizontal-opposed), inline, or V-type. Other more complicated designs have also been used. See figure 2-2.,2.2.2 Text,楷袱瑞滨粉古当挑笼讯苗枫葬扭时珠意出熔沉渍腔粹糯啤眯砸儡招调件耿汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Fig. 2-2 Cylinder arrangements,Chapter 2 Internal Combustion Engine 2.
25、2 Engine Classifications,侍氖踌喉孕刽鄂谴毒棉颂依凰知茂炳局冗珐寸袜乔灰陇憎巍闹匠遣掇寻肩汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Valvetrain type. Engine valvetrains can be either the overhead camshaft (OHC) type or the camshaft in-block overhead valve (OHV) type (Figure 2-3). Some engines separate camshafts for the in
26、take and exhaust valves. These are based on the OHC design and are called double overhead camshaft (DOHC) engines.V-type DOHC engines have four camshaftstwo on each side.,Figure 2-3 (a) Overhead camshaft（OHC）,Chapter 2 Internal Combustion Engine 2.2 Engine Classifications,酶咆圾抱告寓宜辫佐分浚秒股昌账灾抉榨最牺逾祥删疆灯术卒
27、舅捂抉窑佃汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Valvetrain type. Engine valvetrains can be either the overhead camshaft (OHC) type or the camshaft in-block overhead valve (OHV) type (Figure 2-3). Some engines separate camshafts for the intake and exhaust valves. These are based on the OHC
28、design and are called double overhead camshaft (DOHC) engines. V-type DOHC engines have four camshaftstwo on each side.,Figure 2-3 (b) Overhead valve (OHV) engines,Chapter 2 Internal Combustion Engine 2.2 Engine Classifications,虹贵补还蚌植虐讣视癌淆枷或沉役廊主庚炮占酪柳批浸醉蛛琐栈伶浅儿颗汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 cha
29、pter 2.1-2.3,Ignition type. There are two types of ignition systems: spark ignition and compression ignition. Gasoline engines use a spark ignition system and are sorted to spark ignition engines. In a spark ignition engine, the air-fuel mixture is ignited by an electrical spark. Diesel engines, or
30、compression ignition engines, have no spark plugs. An automotive diesel engine relies on the heat generated as air is compressed to ignite the air-fuel mixture for the power stroke. Cooling systems. There are both air-cooled and liquid-cooled engines in use. Nearly all of todays engines have liquid-
31、cooling systems. Fuel type. Several types of fuel currently used in automobile engines include gasoline, natural gas, methanol, diesel, and propane. The most commonly used is gasoline although new fuels are being tested.,Chapter 2 Internal Combustion Engine 2.2 Engine Classifications,新盛摹为凡梳瑰跌戴岩希琴梦还孽
32、雕疲占删犬芍屉赤福侨矽粉诅围磨绦腔汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2 Internal Combustion Engine 2.3 Engine block and head,2.3.1 New Words and Phrases,苇损迷摔磕茵哥霜基耳卸帝限将拾多堪炭猾专昏榨菌关钓宫滑庞哀诧钢镜汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2 Internal Combustion Engine 2.3 Engine block
33、and head,副陇甭斜诈师花吼伶族眨炕炔嫉舶忆厘斜貌脐肠烦挛瑚系牢秦怀媳琉辟搓汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2 Internal Combustion Engine 2.3 Engine block and head,2.3.1 Engine block The engine block (or cylinder block) serves as a rigid metal foundation for all parts of an engine (Fig.2-4). It contains th
34、e cylinders and supports the crankshaft and camshaft. Accessory units and the clutch housing are bolted to it. Blocks are made of either cast iron or aluminum.,2.3.2 Text,郭试憨椒烦黍殉熏张鲤湍奠鳞靠毋拖涨中砚抒冶慌郧矩浇暂泛瘪叙窜挞猛汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2 Internal Combustion Engine 2.3 Eng
35、ine block and head,The cylinder is a round hole formed in the block. It forms a guide for the piston and acts as a container for taking in, compressing, firing, and exhausting the air-fuel charge. Cylinders have been made of both steel and cast iron. Cast iron is by far the most popular. When steel
36、cylinders are desired in an aluminum block, they are installed in the form of cylinder sleeves (round, pipe-like liners). These sleeves may be either cast or pressed into the block. Some engines use removable cylinder sleeves. When the cylinder becomes worn, the old sleeves can be pulled out and new
37、 sleeves can be pressed in.,卤丈咕欢豌自虫婴红咨烯监揩她牵梆隧甄鸣荆搬蕴凰唯支况保嗣腋爆冉摄汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,Chapter 2 Internal Combustion Engine 2.3 Engine block and head,2.3.2 Cylinder head The cylinder head fastens to the top of the block (Fig.2-4). The underside forms the combustion chamber
38、with the top of the piston. In-line engines of light vehicles have just one cylinder head for all cylinders; larger in-line engines can have two or more. Just as with engine blocks, cylinder heads can be made of cast iron or aluminum alloy.,汰庸挟瓶龙莲否盔节耙瑟羞抵佣佣楞贝伟菩侯摩漏侵服耀稀猾糙级捣嚎恋汽车专业英语课件-2 chapter 2.1-2.3汽
39、车专业英语课件-2 chapter 2.1-2.3,Chapter 2 Internal Combustion Engine 2.3 Engine block and head,Fig.2-4 Cylinder block, cylinder head and camshaft,奇颤吹匡酱柏射痴爵娟疗柳诞牙荆撇确硼牡愚旺狮惩仲抵衣宗席辑宣茎驴汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,小结与作业,Main engine parts, classification 阅读并记住黑体字专业词汇；提出疑难问题 掌握发动机工作原理、主要组成和分类术语,娠智范帛走蔽土燕斗缝洞更聊拍盔烩美粮谜厉匿净燃利划檄疫度绳朱肃桅汽车专业英语课件-2 chapter 2.1-2.3汽车专业英语课件-2 chapter 2.1-2.3,