汽车专业英语U1-L2(发动机部分)课件

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,陈长梅,陈长梅,One. Crank-Connecting Rod Mechanism,Crank-connecting rod mechanism consists of piston-connecting rod group, crankshaft flywheel group, engine block group.,One. Crank-Connecting Rod Mech,1,The Engine Block Group,（,1,）,The Cylinder Block,The cylinder block is the basic part of the engine. It forms the main framework or foundation of the engine. Many parts of the engine are fixed to it. These items include,water pump, oil pan, flywheel or clutch housing, ignition distributor, oil pump, fuel pump, and cylinder head.,1The Engine Block Group,（,2,）,The Cylinder Head,The cylinder head is bolted to the cylinder block. The top of the cylinder block is covered with the cylinder head which contains the combustion chamber,（,Fig.2-1,）,.,（2） The Cylinder Head,Single-cylinder engine,cylinder,piston,Piston pin,Connecting rod,crankshaft,Oil pipe,Inlet valve,Exhaust valve,Timing gear,Oil pump,Single-cylinder enginecylinder,connecting rod,flywheel,crankshaft,piston,inlet valve,进水阀,exhaust valve,push rod,Tappet,挺杆,timing gears,Valve gear,阀装置,Connecting rod,connecting rodflywheelcranksha,Engine Body,Crankcase,曲轴箱,cylinder block,cylinder head,cylinder,oil passage,and,water passage,油路和水路,oil pan,The cylinder gasket,气缸垫,Engine BodyCrankcase曲轴箱cylinde,3.cylinder gasket,2.cylinder head,1.Cylinder head cover,4.Pad,衬垫,5.to fit spark plug,安装火花塞,Pre-questions,3.cylinder gasket 2.cylinder h,练 一 练,1- cylinder head cover; 2-cylinder head;,3- cylinder gasket; 4-cylinder block; 5- oil pan,油底壳,气缸垫,气缸体,气缸盖罩,气缸盖,练 一 练1- cylinder head cover;,Components of piston,piston top,piston head,piston skirt,活塞销孔,Piston pin hole,Components of piston piston,Small end,小端,Connecting rod bushing,连杆衬套,Connecting rod,Big end,Connecting rod half shells,半壳,Connecting rod cap,Small end小端Connecting rod bush,compression rings,oil rings,piston pin,piston,connecting rod,crank bearing half shell,曲柄轴承半壳,connecting rod cap,III. Exercises,compression ringsoil ringspist,2,Crankshaft Flywheel Group,（,1,）,Crankshaft,The crankshaft is the main rotating shaft of the engine. Designed into the one-piece crankshaft are areas for main bearing journals, crankpins, counterweights, flywheel flange, and driving hub. The crankshaft and connecting rod convert the reciprocating motion of the piston to the rotary motion of crankshaft.,Crankshafts have drilled oil passages, through which oil can flow from the main bearings to the connecting-rod bearings.,2Crankshaft Flywheel Group,（,2,）,Flywheel,The flywheel is a comparatively heavy wheel, bolted to the flywheel flange on the rear end of the crankshaft.,The inertia of the flywheel tends to keep it rotating at a constant speed. The flywheel also has several other functions, for example, the flywheel has ring gear in its outer circumference,which mesh with teeth located on the starting motor drive pinion in order to crank the engine over. In addition, the rear surface of the flywheel serves as the driving member of the clutch assembly,（,Fig.2-2,）,.,（2） Flywheel,汽车专业英语U1-L2(发动机部分)课件,Pre-questions,Whats the crankshaft assembly composed of?,crankshaft,Bearing,轴承,timing gear,flywheel,belt pulley,皮带轮,piston,Pre-questionsWhats the cranks,3,Piston-Connecting Rod Group,（,1,）,The Connecting Rod,The connecting rod links the piston to the crankshaft. The small end of connecting rod connects with the piston pin and the big end connects with the crank pin of the crankshaft.,3Piston-Connecting Rod Group,（,2,）,The Piston,The engine manufacturer fits a piston into each cylinder of the engine. The piston receives the pressure from the burning air-fuel mixture and converts this pressure into up-and-down reciprocating motion. Because aluminum is half weight less than iron, most of pistons are made from aluminum alloy.,（,3,）,Piston Rings,The piston ring is a springy split metal ring. It is used to provide the necessary seal to eliminate blowby and to control oil consumption. Engine pistons have two kinds of rings,：,gas rings and oil rings.,（2） The Piston,汽车专业英语U1-L2(发动机部分)课件,The piston,Piston top,piston ring,piston pin,connecting rod,The pistonPiston toppiston ri,Two. The Valve Train,The valve train is a series of parts used to open and close the intake and exhaust valves. Meshing the timing gears or installing the timing chains onto the sprockets at a specific place will ensure the valves to open and close at the proper moment in the engines cycle. It consists of,camshaft, tappet, pushrod, rocker arm, valve spring, valve,and so on,（,Fig.2-4,）,.,Two. The Valve TrainThe valve,1,Camshaft,The camshaft is another rotating shaft within the engine, its driven by the engines crankshaft through the timing gears. The camshaft has a series of cams that can change rotary motion to straight-line motion which cause the intake valves and exhaust valves to open. It rotates at the half speed of the crankshaft.,1Camshaft,2,Tappet, Pushrods and Rocker Arms,Tappet rests on a cam of the camshaft. The pushrod is a metal rod that fits between the tappet and the rocker arm. Its function is to transmit cam lobe lift to the rocker arm assembly. The rocker arm is nothing more than a lever. Its function is to convert the up wardmotion of a pushrod into downward motion that compresses the spring and opens the valve.,2Tappet, Pushrods and Rocker,3,Valves and Valve Springs,Modern engines have cylinder heads that contain valves. Each cylinder requires at least two valves,：,an intake valve and an exhaust valve. The valves are compressed and closed by valve springs. As the valve is opened by the camshaft, it compresses the valve spring.,3Valves and Valve Springs,汽车专业英语U1-L2(发动机部分)课件,valves,rocks,push rods,tappets,camshaft,valves rocks push rods tappets,Words,Phrases,（单词和短语）,Words Phrases（单词和短语）,汽车专业英语U1-L2(发动机部分)课件,Pre-questions,What is regarded as the “backbone” of the engine and why?,Crankshaft, because it can change the,reciprocating motion,(,往复运动,)of the piston into,rotary(,旋转,) motion,and handle(,处理,) the entire(,全部,) power output.,Regard as-,译为：被叫做,-,Pre-questionsWhat is regarded,Pre-questions,Whats the function of the flywheel?,helping the engine to run smoothly(,平稳,) during the power stroke and releasing(,释放,) it during the other strokes,；,carrying the clutch, which transmits(,传输,) the drive to the gearbox,；,has the starter ring gear,，,around its.,功 能,Pre-questionsWhats the functi,Pre-questions,Where is the flywheel in the engine?,the rear of the crankshaft.,the starter ring gear,起动环形齿轮,Pre-questionsWhere is the flyw,Pre-questions,What is the function of the valve gear in an internal combustion engine?,Open the inlet valve in time and let the air-fuel mixture into the cylinders in inlet stroke.,Open the exhaust valve in time and let the exhaust gases out of the cylinder in exhaust stroke.,Pre-questionsWhat is the funct,Pre-questions,What does the valve gear of an internal combustion engine consist of?,rocks,push rods,tappets,camshaft,spring,valves,Pre-questionsWhat does the val,Pre-questions,Which component drives the camshaft?,crankshaft,tension gear,crankshaft timing gear,camshaft timing gear,Timing gear-belt,Pre-questionsWhich component d,Pre-questions,What is the function of the valve spring?,The valve spring provides (,提供,) the force (,力量,) necessary (,必要的,) to close the valve and hold (,控制,) it tightly (,紧紧地,) against (,依附着,) its seat (,底座,).,Pre-questionsWhat is the funct,camshaft,camshaft,piston,spring,Piston pin,valve,Connecting rod,camshaftcamshaftpistonspringPi,II. Text Explanation,In an,internal combustion engine,the valve gear,provides,timely,admission of,the air-fuel mixture,into the cylinders and exhaust of the gases from them.,internal combustion engine:,内燃机,admission- into,：将,-,吸入,-,里,译文：,在内燃机中，配气机构能定时地将新鲜的混合气充入气缸，并且将废气从气缸中排出。,II. Text ExplanationIn an int,II. Text Explanation,internal combustion engine,内燃机,valve gear,配气机构,timely,及时的，适时的,fresh charge,新鲜混合气,air- fuel mixture,燃油混合气,II. Text Explanation internal,II. Text Explanation,The valve gear,is composed of,timing gears, camshaft,tappets, push rods, rocks, valves, valve seats, spring with,fasteners,and,valve guides,.,be composed of,由,组成,tappet,挺杆,fastener,紧固件,valve guide,气门导管,II. Text ExplanationThe valve,Valve,Function (,作用,),Open a passage, when moving in one direction(,方向,),and,to close it when moving in the opposite,pzit,（相反的；）,direction.,valve head,stem,Valve Function (作用)valv,III. Exercises,1-rocks,2-valve spring,3-valve guide,4-valve,5-valve seat,6-camshaft,7-tappet,8-push rod,III. Exercises1-rock,翻 译：,1,、,Most engines had two,valves,for,each cylinder, one is for the,inlet,and,the other for the,exhaust,.,译：许多发动机的每个气缸都有两个,气,门,，一个是,进气门,、一个是,排气门,。,翻 译： 1、 Most engines had two,4,、,The valves are,located,within the,cylinder head on most engines designed,today.,are,located,within ,被安装在,-,里面；,designed adj.,有规则的，规矩的；,译：气门被有规则的安装在汽缸头部里面。,4、The valves are locate,Practice,:,P15. E x :1-2,Practice:,汽车专业英语U1-L2(发动机部分)课件,