Unit3 Engine Cooling and Lubrication System市公开课金奖市赛课一等奖课件

1、 Unit 3 Engine Cooling and Lubrication System 1. Engine Cooling SystemThe cooling system is used to keep the engine at the most efficient operating temperature. The cooling system is composed of the water jacket (inside the cylinder block and cylinder head), radiator, water pump, thermostat, fan, ho

2、ses and other components. Fig 1-3-1 shows the parts of a cooling system.efficient 效率高water jacket 水套radiator 散热器，水箱water pump 水泵thermostat 节温器hose 软管第1页Cooling System（冷却系统） Fig. 1-3-11-radiator(散热器) 2-securing clip（固定夹）3-securing rubber（固定橡胶） 4 - upper coolant hose （上部冷却液软管） 5-rubber washer（橡胶垫） 6-r

3、adiator fan（冷却风扇）7- fan ring（风扇罩壳）8-locking bolt（紧固螺栓）9-nut（螺母）10-2 pin connector（双头插式插头）11-lower coolant hose（下部冷却液软管）12-O ring（O型圈）13-connector（连接插头）14-radiator fan thermo switch（散热风扇热敏开关）15- seal(密封圈) 16 drain screw（排水螺栓） 第2页(1) Radiator and FanThe radiator performs the function of cooling the co

4、olant which has passed through the water jacket and become hot, and it is mounted in the front of the vehicle. A fan is mounted behind the radiator to assist the flow of air through the radiator. The fan operates when the engine coolant temperature becomes high in order to prevent it from becoming t

5、oo high.(2) Radiator CapA relief valve ( pressurization valve ) and a vacuum valve ( negative pressure valve ) are built into the radiator cap. It is used to maintain the correct and constant pressure on the cooling system.(3) Water jacketThe water jacket is the open spaces within the cylinder block

6、 and cylinder head through which coolant passes.perform 执行assist 帮助relief valve 泄压阀pressurization 维持大气压水平vacuum valve 真空阀negative pressure 负压第3页(4) Water PumpThe water pump is used to circulate the coolant through the cooling system. It is mounted on the front of the cylinder block and driven by a t

7、iming belt.(5)ThermostatThe thermostat is one of the most important parts of the cooling system, and used to keep the engine coolant at the most efficient temperature. If the coolant remains cold, it will be closed. In this case, a large amount of coolant goes to the by-pass tube without being coole

8、d. The remaining coolant passes through the radiator to be cooled. If the coolant temperature rises to the opening point, the thermostat opens slightly. As the temperature increases further, the thermostat opens more. When the engine is under full load, the thermostat will be fully open. The maximum

9、 amount of coolant will be sent to the radiator for cooling, and a small amount will continue to flow through the by-pass tube. timing belt 正时皮带by-pass tube 旁通管opening point 开启点slightly 轻微地load 负荷第4页2. Engine Lubrication SystemLubrication system has been adopted to supply oil to the moving parts of

10、this engine. The lubrication system consists of an oil pan, oil pump, oil filter, oil cooler and pressure relief valve. Fig 1-3-2 shows the parts of a lubricating system.(1) Oil panThe oil pan is located on the bottom of the engine and holds the excess oil during operation and no running conditions.

11、 A plug in the bottom of the oil pan is used to drain the oil.(2) Oil pumpThe oil pump is located in the crankcase area so that oil can be drawn from the oil pan and sent into the engine.(3) Oil drain plugOil pressure relief valve is used to keep the pressure within the oil system at a constant maxi

12、mum value. lubrication 润滑adopt 采取supply 供给oil pan 油底盘drain 排放draw 抽吸第5页 Lubricating System （润滑系统） Fig. 1-3-21-gasket（密封垫片）2-cap（加油口盖）3-dipstick（机油标尺）4guide（机油标尺导管口）5-oil filter bracket（机油滤清器支架）6-oil pressure switch（机油压力开关）7-O-ring（O形圈）8-oil cooler（机油冷却器）9-oil filter（机油滤清器）10-cap（密封盖）11-drive gear（驱动

13、齿轮）12-gears（齿轮）13-oil pump cover with pressure relief valve（带泄压阀机油泵盖）14-baffle plate（挡油板）15-oildrain plug（放油螺栓）16-seal（密封圈）17-oil pan（机油盘）18-gasket（机油盘垫片）19- suction line（吸油管）20- O ring（O形圈）第6页(4) Oil filterOil Filter is adopted to clean the dirt particles out of the lubricating system. As the oil a

14、nd dirt flow the filter unit, contaminants are trapped inside the filter unit.(5) Oil coolersOil temperature for an engine should be in certain range of degrees. Under normal conditions, oil is cooled by the right amount of oil in the oil pan. When excess temperatures occurs, such as some heavy-duty

15、 gasoline engines and many diesel engines, oil coolers are used to keep the oil cool.(6) Oil pressure sensors and gaugesOil pressure sensors are used to sense the oil pressure in the lubricating system. Oil pressure is usually sensed directly from the main oil gallery. The value is sent to the dashb

16、oard on the vehicle and the operator can read it. The systems commonly used are a pressure gauge and an oil indicator light. The pressure gauge reads the oil pressure within the system. The oil indicator light goes on when oil pressure is lower than a certain value.(7) Marking on oil dipstick（Fig.1-

17、3-3）particle 粒子contaminant 污染物trap 搜集heavy-duty 大功率gasoline 汽油diesel 柴油sense 感觉 gallery 通道dashboard (汽车等) 仪表板gauge 仪表dipstick 油尺第7页 Dipstick（机油尺） Fig. 1-3-31 - Max. mark2 - Min. marka - Area above hatched field up to max. mark: Do not top-up with engine oil!b - Oil level within hatched field: can be

18、 topped-up with engine oilc - Area from min. mark up to hatched field: fill with max. 0.5 liter. of engine oil! 第8页 Translation Skill (3) 词义引申英汉两种语言在表示上有很大差异。翻译时，有些词或词组不能直接搬用词典中释义，若生搬硬套，会使译文生硬艰涩，难以看懂，甚至造成误解。所以，要在搞清原文内涵基础上，依据上下文逻辑关系和汉语搭配习惯，对词义加以引申。若碰到相关专业方面内容，必须选取专业方面术语。引申后词义即使同词典中释义稍有不一样，但能更确切地表示原文意

19、义。第9页1. However, colors can give more force to the form of the product. 欠佳译法：然而，色彩能给与产品更多力量。 引申译法：然而，色彩能使产品外形增添美感。2. Never heat refrigerant container or expose it to naked flame. 欠佳译法：永远不要加热制冷剂贮液罐或将它暴露在裸露火焰中。 引申译法：绝对不要直接加热制冷剂贮液罐或者与明火接触。3. When excess temperatures occurs, such as some heavy-duty gaso

20、line engines and many diesel engines, oil coolers are used to keep the oil cool. 欠佳译法：当过剩温度发生时，如一些重责任汽油机和许多 柴油机，使用机油冷却器使机油冷却。 引申译法：当温度过高时，如一些大功率汽油机和许多柴油机上，使用机油冷却器冷却机油。4. During the first part of his life, Watt studied weather and storm. 欠佳译法：在他生命第一部分，瓦特研究过天气和风暴。 引申译法：瓦特年轻时研究过天气和风暴。第10页 Exercises（练习）

21、1.Translate the following into Chinese（1）oil cooler（2）gasoline engine（3）fan ring（4）locking bolt（5）drive gear（6）suction line（7）oil filter bracket（8）2-pin connector（9）radiator fan thermo switch (10)diesel engine（1）机油冷却器（2）汽油机（3）风扇罩壳（4）紧固螺栓（5）主动齿轮（6）进油管（7）机油滤清器支架（8）双头插式插头（9）散热器风扇热敏开关（10）柴油机第11页 2.Trans

22、late the following into English（1）水套（2）水泵（3）散热器盖（4）真空阀（5）机油泵（6）机油滤清器 （1）Water jacket（2）Water pump（3）Radiator cap（4）Vacuum valve（5）Oil pump（6）Oil filter第12页3.Translate the following sentences into English (1) When the engine is warm, the cooling system is over pressure. It is necessary to release pressure before starting repair work. (2) When installing coolant hoses, route stress-free so that they do not come into c