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Until 11 The automobiles further development will be determined by already existing and steadily increasing requirements, by additional further requirements and by the technical possibilities for meeting these requirements. The following focal points for development and research efforts can be discerned: 汽车的进一步发展取决于已经存在的、目前稳定增长和未来的需求以及为了满足这些需求的技术。下来给出发展研究的几个要点：2 Further improvements of the automobile through products innovation in all classis functions, i. e. performance, fuel economy, environmental impact, safety, comfort and reliability.传统功能的产品革新，比如：性能、燃油经济性、环境友好、安全、舒适性和可靠性。3 Further development of new technologies such as electrics, alternative materials, new test and production methods.新技术的发展，比如：电气、替代材料、新型测试和生产技术。4 Long-range solutions for traffic problems such as highway congestion, smog in cities and carbon dioxide enrichment of our atmosphere. 解决交通问题的技术，比如：交通拥堵，城市烟雾和温室效应。 Until2Exercises1 What is the purpose of an automotive engine? To supply the power needed to move the vehicle.2 What is the difference between a gasoline engine and a diesel engine? A gasoline engine uses an electric ignition system with spark plugs to ignite the fuel. And a diesel engine uses the heat of compression to ignite the fuel.3 What are the basic systems to run a spark-ignition engine required? Fuel system, ignition system, lubricating system and cooling system.4 List the strokes of a four-stroke-cycle gasoline engine operation. The intake stroke, the compression stroke, the power stroke and the exhaust stroke.5 What is the function of the flywheel? It is used to store sufficient energy to move the piston and related parts through the other strokes (exhaust, intake and compression)Translate.1 A car usually has a piston engine. It consists of several moving part: pistons, connecting rods, crankshaft, camshaft, valve lifters, intake valves and exhaust valves. The cast iron or aluminum engine block holds the moving parts. The engine block has a series of holes which are called cylinders. The cylinders can be arranged in line or in a V-shape and in the upper part of the block. Each cylinder holds a piston and the connecting rod. A circular ring is used to seal the small gap between the piston and the cylinder wall. The lower part of the block is called crankcase which holds the crankshaft with bearing mounts. Pistons are connected to the crankshaft by connecting rods. 汽车一般使用活塞式发动机。活塞式发动机由活塞、连杆、曲轴、凸轮轴、气门挺杆、进气门和排气门等运动部件组成。这些运动部件安置在铸铁或铝合金机体内。发动机体上有些凹洞，这些凹洞被称作气缸。气缸在机体上部呈直列式或V型排列。每个气缸都有活塞和连杆。活塞和气缸壁之间的微小缝隙通过一个圆环密封。机体的下部是曲轴箱，里面是带有轴承的曲轴。活塞和曲轴之间通过连杆连接。2 The cylinder heads are the top covers of the cylinders which are tightly bolted to the top of the block. The cylinder heads contain combustion chambers. Each combustion chamber contains at least one intake and exhaust valve and one spark plug per cylinder. The valves are opened and closed in a specific sequence with valve lifters controlled by the camshaft. The camshaft is connected to the crankshaft through a time belt. 气缸盖是气缸的上盖，其通过螺栓与上机体连接。气缸盖下是燃烧腔。每个气缸的每个燃烧腔都至少要有一个进气门，一个排气门和一个火花塞。气门被由凸轮轴控制的气门挺杆按一定的顺序打开和关闭。凸轮轴和曲轴之间通过正时带连接。Unit 3 Automotive Lubrication System Exercises1 What is the purpose of automobile lubrication system? Reducing friction to minimize wear and loss of power2 Explain what the function of oil is. Form a seal between the pistons, rings, and cylinders. Cool engine parts. Clean carbon and varnish. Absorb the shock and dampen the noise.4 Name at least three common additives used in compounding oils. Antiscuff additives. Corrosion inhibitor. Detergent-dispersant. Foam inhibitor. Viscosity index improver.6 Explain how oil reduces friction. All moving parts ride on a thin film of oil instead of metal-to-metal contact.7 Define the word viscosity. The body and fluidity of the oil.8 What is detergent oil? Clean engine parts during operation and keep contaminants in suspension in the oil.9 What is the difference between the full flow filter system and the bypass filter system? The bypass filter system allow oil to circulate through the engine when the filter becomes too clogged for oil to pass through it.Translate1 The purpose of the lubrication system is to circulate oil through the engine. Many parts inside the engine, such as the camshaft, crankshaft, connecting rods, and pistons are connected to other metal parts. When parts rub together, friction is created. Friction produce heat. Although two metal surfaces may appear smooth to the naked eye, they may look rough when seen through a microscope.润滑系统的作用是让润滑油在发动机循环。发动机内部许多部件，如：凸轮轴，曲轴，挺杆和活塞都与其他金属部件相连。当这些部件相互接触，就产生了摩擦。摩擦就会产生热量。肉眼看上去，两个金属的表面非常光滑，但通过显微镜观察，它们实际上非常粗糙。2 An engine must have a good lubrication system. Without it, the friction heat from the contact of the moving parts would wear the parts and causes loss. Oil, when placed between two moving parts, separates them with a film. This oil film prevents the parts from rubbing against each other. This oil film also cushions the parts, giving quieter and smoother engine operation.发动机必须要有好的润滑系统。没有润滑系统，运动部件之间摩擦产生的热量会磨损部件和耗费功率。当润滑油位于两个运动部件之间时，就会产生一层油膜来分离这两个部件。油膜可以防止两个部件相互摩擦，还起到类似缓冲垫的作用，可以让发动机安静平稳的工作。Unit 4 The Cooling SystemExercises1 What is the function of the cooling system? To remove excess heat from the engine, to keep the engine operating at its most efficient temperature, and to get the engine up to the correct temperature as soon as possible after starting.2 What are the most common causes of engine overheating? Fuel burning engines produce enormous amounts of heat. The exhaust system takes away much of the heat, but parts of the engines, such as the cylinder walls, pistons, and cylinder head, absorb large amounts of the heat.3 Will installing a lower temperature thermostat help the engine run cooler and prevent it from overheating? No. The thermostats main job is to allow the engine to heat up quickly, and then to keep the engine at a constant temperature.4 Why are liquid-cooling system pressurized? It can increase the boiling point of the coolant.Translate1 The fans activity is not always necessary, and it take power from the engine to spin. For this reason a thermostatic control, or fan clutch, is often used to reduce drive torque when it isnt needed (variable-speed fan).因为风扇需要从发动机吸取能量来旋转叶片，风扇并不需要持续运转。因此，当不需要风扇运转时，温度控制器或者风扇离合器经常被用来减小转矩（变速风扇）2 A different type of fan uses centrifugal force to move its flexible plastic blades, by flattening them when the engine rpm is high (flexible-blade fan). The less angle the blade have, the less power they use. The idea of these units is to save horsepower and to reduce the noise the fan makes.当发动机转速较高时，有一种风扇使用离心力来移动可动的塑料叶片（变叶片风扇）。叶片的迎风角越小，风扇所消耗的功率越小。这些部件的设计是用来减小功率和风扇产生的噪音。3 A fan can have from four to six blades to suck the air through the radiator. Often the radiator has a shroud for the fan to keep it from re-circulating the same hot air that has collected behind the radiator. Many fans have irregularly spaced blades to reduce resonant noise.风扇拥有4到6个叶片来吸取来自散热器的空气。通常散热器被裹盖，防止风扇将散热器后部聚集的热空气重复循环。许多风扇有着不规则的叶片来减小共振噪音。4 Another function of the expansion tank is to remove air bubbles from the cooling system. Coolant without air-bubbles is much more efficient than coolant with air bubbles, because it absorbs heat much faster. The advantage of the expansion tank is that while the level of coolant contained in it rises and falls, the radiator is always full.溢流箱的另一个作用是去除来自冷却系统的气泡。没有气泡的冷却液要比含有气泡的冷却液更有效，因为它可以更快地吸收热量。无论溢流箱内的液位上升或下降，散热器总是满的。
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