概念发展和汽车设计毕业课程设计外文文献翻译、外文文献翻译、中英文翻译

毕业设计（论文）外文文献翻译文献、资料中文题目：汽车发动机文献、资料英文题目：AUTOMOTIVE ENGINE文献、资料来源：文献、资料发表（出版）日期：院（部）：专业：机械设计制造及其自动化（车辆工程）班级：姓名：学号：指导教师：翻译日期： 2017.02.14译文题目： Automobile engineAUTOMOTIVE ENGINE1 Engine Classification and Overall MechanicsThe automobile engines can be classified according to: (1) cycles, (2) cooling system, (3) fuel system, (4) ignition method, (5) valve arrangement, (6) cylinder arrangement, (7) engine speed.Engines used in automobiles are the internal combustion heat engines. Theburning of gasoline inside the engine produces high pressure in the engine combustion chamber. This high pressure force piston to move, the movement is carried by connecting rods to the engine crankshaft. The crankshaft is thus made to rotate: therotary motion is carried through the power train to the car wheels so that they rotateand the car moves.The engine requires four basic systems to run (Fig. 2-1). Diesel engines requirethree of these systems. They are fuel system, ignition system (except diesel), lubricating system and cooling system. However, three other related systems are also necessary. These are the exhaust system, the emission-control system, and the starting system. Each performs a basic job in making the engine run.Fig. 2-1 The engine construction2 Engine Operating PrinciplesFig. 2-2 Engine termsThe term “stroke” is used to describe the movement of the piston within the cylinder. The movement of the piston from its uppermost position (TDC, top dead center) to its lowest position (BDC, bottom dead center) is called a stroke. The operating cycle may require either two or four strokes to complete. Most automobile engines operate on the four stroke cycle (Fig. 2-2).In four-stroke engine, four strokes of the piston in the cylinder are required to complete one full operating cycle. Each stroke is named after the action. It performs intake, compression, power, and exhaust in that order (Fig. 2-3).Intake stroke Compression stroke Power stroke Exhaust strokeFig. 2-3 Four-stroke-cycle gasoline engine1. The intake strokeThe intake stroke begins with the piston near the top of its travel. As the piston begins its descent, the exhaust valve closes fully, the intake valve opens and the volume of the combustion chamber begins to increase, creating a vacuum. As the piston descends, an air/fuel mixture is drawn from the carburetor into the cylinder through the intake manifold. The intake stroke ends with the intake valve close just after the piston has begun its upstroke.2. Compression strokeAs the piston is moved up by the crankshaft from BDC, the intake valve closes. The air/fuel mixture is trapped in the cylinder above the piston. Future piston travelcompresses the air/fuel mixture to approximately one-eighth of its original volume (approximately 8:1 compression ratio) when the piston has reached TDC. This completes the compression stroke.3. Power strokeAs the piston reaches TDC on the compression stroke, an electric spark is produced at the spark plug. The ignition system delivers a high-voltage surge of electricity to the spark plug to produce the spark. The spark ignites, or sets fire to, the air/fuel mixture. It now begins to burn very rapidly, and the cylinder pressure increases to as much as 3-5MPa or even more. This terrific push against the piston forces it downward, and a powerful impulse is transmitted through the connecting rod to the crankpin on the crankshaft. The crankshaft is rotated as the piston is pushed down by the pressure above it.4. Exhaust strokeAt the end of the power stroke the camshaft opens the exhaust valve, and the exhaust stroke begins. Remaining pressure in the cylinder, and upward movement of the piston, force the exhaust gases out of the cylinder. At the end of the exhaust stroke, the exhaust valve closes and the intake valve opens, repeating the entire cycle of events over and over again.3 Engine Block and Cylinder Head3.1 Engine BlockThe engine block is the basic frame of the engine. All other engine parts either fit inside it or fasten to it. It holds the cylinders, water jackets and oil galleries (Fig. 2-4). The engine block also holds the crankshaft, which fastens to the bottom of the block. The camshaft also fits in the block, except on overhead-cam engines. In most cars, this block is made of gray iron, or an alloy (mixture) of gray iron and other metals, such as nickel or chromium. Engine blocks are castings.Fig. 2-4 V6 engine blockSome engine blocks, especially those in smaller cars, are made of cast aluminum. This metal is much lighter than iron. However, iron wears better than aluminum. Therefore, the cylinders in most aluminum engines are lined with iron or steel sleeves. These sleeves are called cylinder sleeves. Some engine blocks are made entirely of aluminum.3.2 Cylinder SleevesCylinder sleeves are used in engine blocks to provide a hard wearing material for pistons and piston rings. The block can be made of one kind of iron that is light and easy to cast while the sleeves uses another that is better able to stand up wear and tear. There are two main types of sleeves: dry and wet (Fig. 2-5).Dry sleeve Wet sleeveFig. 2-5 Cylinder sleeve3.3 Cylinder HeadThe cylinder head fastens to the top of the block, just as a roof fits over a house. The underside forms the combustion chamber with the top of the piston. In-line engine 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. The cylinder head carries the valves, valve springs and the rockers on the rocker shaft, this part of valve gear being worked by the pushrods. Sometimes the camshaft is fitted directly into the cylinder head and operates on the valves without rockers. This is called an overhead camshaft arrangement.3.4 GasketThe cylinder head is attached to the block with high-tensile steel studs. The joint between the block and the head must be gas-tight so that none of the burning mixture can escape. This is achieved by using cylinder head gasket. Gaskets are also used to seal joins between the other parts, such as between the oil pan, manifolds, or water pump and the blocks.3.5 Oil PanThe oil pan is usually formed of pressed steel. The oil pan and the lower part of cylinder block together are called the crankcase; they enclose, or encase, the crankshaft. The oil pump in the lubricating system draws oil from the oil pan and sends it to all working parts in the engine. The oil drains off and run down into the pan. Thus, there is a constant circulation of oil between the pan and the working parts of the engine.4 Piston Assembly, piston rings , The piston pin ,Connecting Rods, Crankshafts And Flywheel4.1 PistonPiston rings and the piston pin are together called the piston assembly (Fig. 2-6).。

( 4 )计算机模拟冲压成形及虚拟试模技术:(5)模具制造技术,模块式冲压的突出优点在于能把冲压加工系统的柔性与高效生产有机的结合在一起。

柔性的含义较广, 如冲压件的几何形状的多种要求, 只要通过自由编程就可获得, 体现了加工形状的柔性。

又如既适用大批量单品种冲压件的生产, 更对小批量多品种加工发挥也表性。

概括而言,模块式冲压的持点是:(1)在冲压成形过程中可快速更換组合模具以提高生产效率,(2)由于具有带材的供带和矫带装置, 可省却另设上料下料工序,(3 )实现了大工件的不停机加工;(4)既能独立又能成系列的控制组合冲模动作, 能连续进行冲压加工;( 5)冲模具有可编和的柔性特点。

一种模块式冲压加工系统由一台带有控制功能模块式冷冲压的压力机、卷材带材送进装轩、带材矫正机及可编程进给装置等构成。

这种冲压系统在运行时可进行冲模横向位移、带材进给定位、冲模重复运行及自动调整下工步的冲模调整等多项功能。

由于在冲压过程中进行可编程冲压, 使这种模块式冲压系统能柔性地适应生产需求,能在相同带材上进行曲不同工件及批次的混合生产,实现不停机的串接式加工,还同时在工件西面冲压加工,极大地提高了工作效率,有资料表明, 模块式冲压成形使加工费用能下降至40%-50%。

当前模块式冲压装置的集成度是很高的, 在宽度为300MM 尺寸范围内可安排达35个模具, 通过冲模上端的顶板可对冲模进行独立式系列控制, 即形成冲模的集成控制。

整个系统的编程可在windows用户界面和菜単下实现,编程涉及模具沿者横向定位納的何服驱动定位,带材的检验矫正及纵向进给定位, 冲模的质量跟踪检验, 冲模的调整及状况监控等多功能。

当冲模重新配置成更換时,这些变化则会被参数并被控制系统所贮存, 以务下次査询和调用。

冲模数据包括有冲头及其组合标记, 冲头组合在模具中的 X、Y坐标位置及模具轴编号等信息。

l毫米冲压是指汽车车身冲压件的精度控制在0-1. OMM 的范围内,与过去制造业通行的误差2MM 相比, 是个非常大的提高。

毕业设计(论文）外文文献翻译院系：财务与会计学院年级专业：201＊级财务管理姓名:学号：132148*＊*附件: 财务风险管理【Abstract】Although financial risk has increased significantly in recent years risk and risk management are not contemporary issues。

The result of increasingly global markets is that risk may originate with events thousands of miles away that have nothing to do with the domestic market。

Information is available instantaneously which means that change and subsequent market reactions occur very quickly。

The economic climate and markets can be affected very quickly by changes in exchange rates interest rates and commodity prices。

Counterparties can rapidly become problematic。

As a result it is important to ensure financial risks are identified and managed appropriately. Preparation is a key component of risk management。

【Key Words】Financial risk，Risk management，YieldsI. Financial risks arising1.1What Is Risk1.1.1The concept of riskRisk provides the basis for opportunity. The terms risk and exposure have subtle differences in their meaning. Risk refers to the probability of loss while exposure is the possibility of loss although they are often used interchangeably。

中国汽车工业及其全球化（节译）摘要：由于改革开放政策的实行，中国汽车行业的实现了飞速的发展，特别是在20世纪90年代初期。

中国政府一直鼓励国内和合资公司通过引进日本和欧美的汽车及其零部件制造商的直接投资，来向中国内部扩张。

中国的目标是在2020年成为全球车业举足轻重的角色。

本文旨在分析中国的汽车工业目前存在的优势和弱点，并且讨论如果中国汽车行业如果要实现全球化，什么将是它所需要的。

本文将侧重点放在“与合资企业相关的政府政策”，“市场拓展”，“如何解决规模和范围问题”以及“需要解决的质量问题”这些点上----如果中国车企想与西方国家更先进的汽车企业一争高下的话。

最后，中国汽车企业在发达经济体市场参与中是难还是易？本文将对此进行探讨评估。

出口潜力分析结论：很显然，中国的国内汽车生产商不足以对世界上先进的汽车厂商形成的严峻挑战。

最近关于安全性和废气排放测试的实验中，给中国的汽车制造商之间带来了更严峻的气氛，但这不应该是西方汽车厂家得意的理由。

中国将借鉴他们的经验，很可能在未来几年内，将缩小在设计和技术方面与西方的差距。

当中国汽车开始进入西方市场，甚至像奇瑞这种在中国享有良好的声誉的汽车公司将大力跟进，它将采取低价策略进入欧美市场，估计比美国或欧洲等值商品低30％。

此外，中国企业将要面对经销商建立的巨额成本，而在美国，将需要至少250个经销网点，其初始建设成本可能削弱其企业竞争力。

全文结论：从上述很明显，中国汽车品牌在全球汽车领域走向强大的道路上有它极其强大的力量，并且这已经不是它走得是否好的问题了，而是中国本土汽车制造商什么时候能够有足够的准备，试图渗透进先进的并且已经饱和的西方和日本汽车市场。

然而，有充分的证据表明，在大约五到十年间这将不难看到。

而且它发生的时候，中国的汽车制造商将按照以前日本和韩国走过的道路，以比日韩更快的速度扩张。

在中国进入欧美日韩汽车市场之前，中国需要处理其自主汽车行业所面临的严重问题。

ChassisChassis include the clutch , the transmission, the drive shaft, the final drive assembly, the front suspension, the rear suspension, the steering system ,the brake system, the wheels and tires.1.clutchThe engine produces the power to drive the vehicle . The drive line or drive train transfer the power of the engine to the wheels . The drive train consists of the parts from the back of the flywheel to the wheels . These parts include the clutch , the transmission ,the drive shaft ,and the final drive assembly .The clutch which includes the flywheel ,clutch disc , pressure plate , springs , pressure plate cover and the linkage necessary to operate the clutch is a rotating mechanism between the engine and the transmission . It operates through friction which comes from contact between the parts . That is the reason why the clutch is called a friction mechanism . After engagement, the clutch must continue to transmit all engine torque to transmission depending on the friction without slippage . The clutch is also used to disengage the engine from the drive train whenever the gears in the transmission are being shifted from gear ratio to another .To start the engine or shift the gears , the driver has to depress the clutch pedal with the purpose of disengagement the transmission from the engine . At that time , the driven members connected to the transmission input shaft are either stationary or rotating at a speed that is slower of faster than the driving members connected to engine crankshaft . There is no spring pressure on the clutch assembly parts . So there is no friction between the driving members and driven members . As the driver lets loose the clutch pedal , spring pressure increase on the clutch parts . Friction between the parts also increases . The pressure exerted by the springs on the driven members is controlled by the driver through the clutch pedal and linkage . The positive engagement of the driving and driven members is made possible the friction between the surfaces of the members . When full spring pressure is applied , the speed of the driving and driven members should be the same . At the moment , the clutch must actas a coupling device and transmit all engine power to the transmission , without slipping .However , the transmission should be engaged to the engine gradually in order to operate the car smoothly and minimize torsional shock on the drive train because an engine at idle just develop little power . Otherwise , the driving members are connected with the driven members too quickly and the engine would be stalled .The flywheel is a major part of the clutch . The flywheel mounts to the engine‟s crankshaft and transmits engine torque to the clutch assembly . The flywheel , when coupled with the clutch disc and pressure plate makes and breaks the flow of power the engine to the transmission .The flywheel provides a mounting location for the clutch assembly as well . When the clutch is applied , the flywheel transfers engine torque to the clutch disc . Because of its weight , the flywheel helps to smooth engine operation . The flywheel also has a large ring gear at its outer edge , which engages with a pinion gear on the starter motor during engine cranking .The clutch disc fits between the flywheel and the pressure plate . The clutch disc has a splined hub that fits over splines on the transmission input shaft . A splined hub has grooves that match splines on the shaft . These splines fit in the grooves . Thus , the two parts held together . However , back –and –forth movement of the disc on the shaft is possible . Attached to the input shaft , the disc turns at the speed of the shaft .The clutch pressure plate is generally made of cast iron . It is round and about the same diameter as the clutch disc . One side of the pressure plate is machined smooth . This side will press the clutch disc facing are against the flywheel . The outer side has shapes to facilitate attachment of spring and release mechanism . The two primary types of pressure plate assemblies are coil spring assembly and diaphragm spring .In a coil spring clutch the pressure plate is backed by a number of coil springs and housed with them in a pressed –steed cover bolted to the flywheel . The spring push against the cover . Neither the driven plate nor the pressure plate is connected rigidly to the flywheel and both can move either towards it o away . When the clutch pedal is depressed a thrust pad riding on a carbon or ball thrust bearing is forced towards the flywheel . Levers pivoted sothat they engage with the thrust pad at one end and the pressure plate tat the other end pull the pressure plate back against its springs . This releases pressure on the driven plate disconnecting the gearbox from the engine .Diaphragm spring pressure plate assemblies are widely used in most modern cars . The diaphragm spring is a single thin sheet of metal which yields when pressure is applied to it . When pressure is removed the metal spring back to its original shape . The center portion of the diaphragm spring is slit into numerous fingers that act as release levers . When the clutch assembly rotates with the engine these weights are flung outwards by centrifugal plate and cause the levers to press against the pressure plate . During disengagement of the clutch the fingers are moved forward by the release bearing . The spring pivots over the fulcrum ring and its outer rim moves away from the flywheel . The retracting spring pulls the pressure plate away from the clutch plate thus disengaging the clutch .When engaged the release bearing and the fingers of the diaphragm spring move towards the transmission . As the diaphragm pivots over the pivot ring its outer rim forces the pressure plate against the clutch disc so that the clutch plate is engaged to flywheel .The advantages of a diaphragm type pressure plate assembly are its compactness , lower weight , fewer moving parts , less effort to engage , reduces rotational imbalance by providing a balanced force around the pressure plate and less chances of clutch slippage .The clutch pedal is connected to the disengagement mechanism either by a cable or , more commonly , by a hydraulic system . Either way , pushing the pedal down operates the disengagement mechanism which puts pressure on the fingers of the clutch diaphragm via a release bearing and causes the diaphragm to release the clutch plate . With a hydraulic mechanism , the clutch pedal arm operates a piston in the clutch master cylinder . This forces hydraulic fluid through a pipe to the cutch release cylinder where another operates the clutch disengagement mechanism by a cable .The other parts including the clutch fork , release bearing , bell – housing , bell housing cover , and pilot bushing are needed to couple and uncouple the transmission . The clutch fork , which connects to the linkage , actually operates the clutch . The release bearing fits between the clutch fork and the pressure plate assembly . The bell housing covers the clutchassembly . The bell housing cover fastens to the bottom of the bell housing . This removable cover allows a mechanic to inspect the clutch without removing the transmission and bell housing . A pilot bushing fits into the back of the crankshaft and holds the transmission input shaft .2.AUTOMATIC TRANSMISSIONThe modern automatic transmission is by far , the most complicated mechanical component in today‟s automobile . It is a type of transmission that sifts itself . A fluid coupling or torque converter is used instead of a manually operated clutch to connect the transmission to the engine .There are two basic types of automatic transmission based on whether the vehicle is rear wheel drive or front wheel drive . On a rear wheel drive car , the transmission is usually mounted to the back of the engine and is located under the hump in the center of the floorboard alongside the gas pedal position . A drive shaft connects the transmission to the final drive which is located in the rear axle and is used to send power to the rear wheels . Power flow on this system is simple and straight forward going from the engine , through the torque converter , then trough the transmission and drive shaft until it reaches the final drive where it is split and sent to the two rear transmission .On a front wheel drive car , the transmission is usually combined with the final drive to form what is called a transaxle . The engine on a front wheel drive car is usually mounted sideways in the car with the transaxle tucked under it on the side of the engine facing the rear of the car . Front axles are connected directly to the transaxle and provide power to front wheels . In this example , power floes from the engine , through the torque converter to a larger chain that sends the power through a 180 degree turn to the transmission that is along side the engine . From there , the power is routed through the transmission to the final drive where it is split and sent to the two front wheels through the drive axles .There are a number of other arrangements including front drive vehicles where the engine is mounted front to back instead of sideways and there are other systems that drive all four wheels but the two systems described here are by far the most popular . A much lesspopular rear and is connected by a drive shaft to the torque converter which is still mounted on the engine . This system is found on the new Corvette and is used in order to balance the weight evenly between the front and rear wheels for improved performance and handling . Another rear drive system mounts everything , the engine , transmission and final drive in the rear . This rear engine arrangement is popular on the Porsche.The modern automatic transmission consists of many components and systems that designed to work together in a symphony of planetary gear sets , the hydraulic system, seals and gaskets , the torque converter , the governor and the modulator or throttle cable and computer controls that has evolved over the years into what many mechanical inclined individuals consider to be an art from . Here try to used simple , generic explanation where possible to describe these systems .1）Planetary gear setsAutomatic transmission contain many gears in various combinations . In a manual transmission , gears slide along shafts as you move the shift lever from one position to another , engaging various sizes gears as required in order to provide the correct gear ratio . In an automatic transmission , how ever , the gears are never physically moved and are always engaged to the same gears . This is accomplished through the use of planetary gear sets .The basic planetary gear set consists of a sun gear , a ring and two or more planet gears , all remaining in constant mesh . The planet gears are connected to each other through a common carrier which allows the gears to spin on shafts called “pinions” which are attached to the carrier .One example of a way that this system can be used is by connecting the ring gear to the input shaft coming from the engine , connecting the planet carrier to the output shaft , and locking the sun gear so that it can‟t move . In this scenario , when we turn the ring gear , the planets will “walk” along the sun gear ( which is held stationary ) causing the planet carrier to turn the output shaft in the same direction as the input shaft but at a slower speed causing gear reduction ( similar to a car in first gear ) .If we unlock the sun gear and lock any two elements together , this will cause all three elements to turn at the same speed so that to output shaft will turn at the same rate of speed asthe input shaft . This is like a car that is third or high gear . Another way we can use a planetary gear set is by locking the planet carrier from moving , then applying power to the ring gear which will cause the sun gear to turn in opposite direction giving us reverse gear .The illustration in Figure shows how the simple system described above would look in an actual transmission . The input shaft is connected to the ring gear , the output shaft is connected to the planet carrier which is also connected to a “Multi-disk” clutch pack . The sun gear is connected to drum which is also connected to the other half of the clutch pack . Surrounding the outside of the drum is a band that can be tightened around the drum when required to prevent the drum with the attached sun gear from turning .The clutch pack is used , in this instance , to lock the planet carrier with the sun gear forcing both to turn at the same speed . If both the clutch pack and the band were released , the system would be in neutral . Turning the input shaft would turn the planet gears against the sun gear , but since noting is holding the sun gear , it will just spin free and have no effect on the output shaft . To place the unit in first gear , the band is applied to hold the sun gear from moving . To shift from first to high gear , the band is released and the clutch is applied causing the output shaft to turn at the same speed as the input shaft .Many more combinations are possible using two or more planetary sets connected in various way to provide the different forward speeds and reverse that are found in modern automatic transmission .2）Clutch packA clutch pack consists of alternating disks that fit inside a clutch drum . Half of the disks are steel and have splines that fit into groves on the inside of the drum . The other half have a friction material bonded to their surface and have splines on the inside edge that fit groves on the outer surface of the adjoining hub . There is a piston inside the drum that is activated by oil pressure at the appropriate time to squeeze the clutch pack together so that the two components become locked and turn as one .3）One-way ClutchA one-way clutch ( also known as a “sprag” clutch ) is a device that will allow a component such as ring gear to turn freely in one direction but not in the other . This effect is just like thatbicycle , where the pedals will turn the wheel when pedaling forward , but will spin free when pedaling backward .A common place where a one-way clutch is used is in first gear when the shifter is in the drive position . When you begin to accelerate from a stop , the transmission starts out in first gear . But have you ever noticed what happens if you release the gas while it is still in first gear ? The vehicle continues to coast as if you were in neutral . Now , shift into Low gear instead of Drive . When you let go of the gas in this case , you will feel the engine slow you down just like a standard shift car . The reason for this is that in Drive , one-way clutch is used whereas in Low , a clutch pack or a band is used .4）Torque ConverterOn automatic transmission , the torque converter takes the place of the clutch found on standard shift vehicles . It is there to allow the engine to continue running when the vehicle comes to a stop . The principle behind a torque converter is like taking a fan that is plugged into the wall and blowing air into another fan which is unplugged . If you grab the blade on the unplugged fan , you are able to hold it from turning but as soon as you let go , it will begin to speed up until it comes close to speed of the powered fan . The difference with a torque converter is that instead of using air it used oil or transmission fluid , to be more precise .A torque converter is a lager doughnut shaped device that is mounted between the engine and the transmission . It consists of three internal elements that work together to transmit power to the transmission . The three elements of the torque converter are the pump , the Turbine , and the Stator . The pump is mounted directly to the torque housing which in turn is bolted directly to the engine‟s crankshaft and turns at engine speed . The turbine is inside the housing and is connected directly to the input shaft of the transmission providing power to move the vehicle . The stator is mounted to a one-way clutch so that it can spin freely in one direction but not in the other . Each of the three elements has fins mounted in them to precisely direct the flow of oil through the converter .With the engine running , transmission fluid is pulled into the pump section and is pushed outward by centrifugal force until it reaches the turbine section which stars it running . The fluid continues in a circular motion back towards the center of the turbine where it entersthe stator . If the turbine is moving considerably slower than the pump , the fluid will make contact with the front of the stator fins which push the stator into the one way clutch and prevent it from turning . With the stator stopped , the fluid is directed by the stator fins to re-enter the pump at a “help” angle providing a torque increase . As the speed of the turbine catches up with the pump , the fluid starts hitting the stator blades on the back-side causing the stator to turn in the same direction as the pump and turbine . As the speed increase , all three elements begin to turn at approximately the same speed . Sine the …80s , in order to improve fuel economy , torque converters have been equipped with a lockup clutch which locks the turbine to the pump as the vehicle reaches approximately 40-50 mph . This lockup is controlled by computer and usually won‟t engage unless the transmission is in 3rd or 4th gear .5）Hydraulic SystemThe hydraulic system is a complex maze of passage and tubes that sends that sends transmission fluid and under pressure to all parts of the transmission and torque converter and . Transmission fluid serves a number of purpose including : shift control ,general lubrication and transmission cooling . Unlike the engine ,which uses oil primary for lubrication ,every aspect of a transmission …s function is dependant on a constant supply of fluid is send pressure . In order to keep the transmission at normal operating temperature , a portion of the fluid is send to through one of two steel tubes to a special chamber that is submerged in anti-freeze in the radiator . Fluid passing through this chamber is cooled and then returned to the transmission through the other steel tube . A typical transmission has an avenge of ten quarts of fluid between the transmission , torque converter , and cooler tank , In fact , most of the components of a transmission are constantly submerged in fluid including the clutch packs and bands . The friction surfaces on these parts are designed to operate properly only when they are submerged in oil .6）Oil PumpThe transmission oil pump ( not to confused with the pump element inside the torque converter ) is responsible for producing all the oil pressure that is required in the transmission . The oil pump is mounted to front of the transmission case and is directly connected to aflange on the engine crankshaft , the pump will produce pressure whenever the engine is running as there is a sufficient amount of transmission fluid available . The oil enters the pump through a filter that is located at bottom of the transmission oil pan and travels up a pickup tube directly to the oil pump . The oil is then sent , under pressure to the pressure regulator , the valve body and the rest of the components , as required .7）Valve BodyThe valve body is the control center of the automatic transmission . It contains a maze of channels and passages that direct hydraulic fluid to the numerous valves which when activate the appropriate clutch pack of band servo to smoothly shift to the appropriate gear for each driving situation . Each of the many valves in the valve body has a specific purpose and is named for that function . For example the 2-3 shift valve activates the 2nd gear up-shift or the 3-2 shift timing valve which determines when a downshift should occur .The most important valve and the one that you have direct control over is the manual valve. The manual valve is directly connected to the gear shift handle and covers and uncovers various passages depending on what position the gear shift is paced in . When you place the gear shift in Drive , for instance , the manual valve directs fluid to the clutch pack ( s ) that activates 1st gear . It also sets up to monitor vehicle speed and throttle position so that it can determine the optimal time and the force for the 1-2 shift . On computer controlled transmission , you will also have electrical solenoids that are mounted in the valve body to direct fluid to the appropriate clutch packs or bands under computer control to more precisely control shift points .8）Seals and GasketsAn automatic transmission has many seals and gaskets to control the flow of hydraulic fluid and to keep it from leaking out . There are two main external seals : the front seal and the rear seal . The front seal seals the point where the torque converter mounts to the transmission case . This seal allows fluid to freely move from the converter to the transmission but keeps the fluid from leaking out . The rear seal keeps fluid from leaking past the output shaft .A seal is usually made of rubber ( similar to the rubber in a windshield wiper blade )and is used to keep oil from leaking past a moving part such as a spinning shaft . In some cases , the rubber is assisted by a spring that holds he rubber in close contact with the spinning shaft .A gasket is a type of seal used to seal two stationary parts that are fasted together . Some common gasket materials are : paper , cork , rubber , silicone and soft metal .Aside from the main seals , there are also a number of other seals and gasket that vary from transmission to transmission . A common example is the rubber O-ring that seals the shaft for the shift control lever . This is the shaft that you move when you manipulate the gear shifter . Another example that is common to most transmission is the oil pan gasket . In fact , seals are required anywhere that a device needs to pass through the transmission case with each one being a potential source for leaks .9）Computer ControlsThe computer uses sensors on the engine and transmission to detect such things as throttle position , vehicle speed , engine speed , engine load , stop light switch position , etc . to control exact shift points as well as how soft or firm the shift should be . Some computerized transmission even learn your driving style and constantly adapt to it so that every shift is timed precisely when you would need it .Because of computer controls , sports models are coming out with the ability to take manual control of the transmission as through it were a stick shift lever through a special gate , then tapping it in one direction or the other in order to up-shift at will . The computer monitors this activity to make sure that the driver dose not select a gear that could over speed the engine and damage it .Another advantage to these “ smart” transmission is that they have a self diagnostic mode which can detect a problem early on and warn you with an indicator light on the dash .A technician can then plug test equipment in and retrieve a list of trouble codes that will help pinpoint where the problem is .3．The Differential SystemWhen a vehicle is cornered the inner wheel moves through a shorter distance than theouter wheel . This means that the inner wheel must slow down and the outer wheel must speed up . During this period it is desirable that each driving maintains its driving action . The differential performs these two tasks . The principle of the bevel type differential can be seen if the unit is considered as two discs and a lever .When the vehicle is traveling straight , the lever will divide the diving force equally and both discs will move the same amount .When the vehicle corners , the driving will still be divided equally but the inner disc will now move through a smaller distance ;this will cause the lever to pivot about its center which will prize forward the outer disc to give it a greater movement . This action shows that the torque applied to each driving wheel is always equal – hence the differential is sometimes called a torque equalizer .4．Brake SystemThe breaking system is the most important system in cars . If the brakes fail , the result can be disastrous . Brakes are actually energy conversion devices , which convert the kinetic energy ( momentum ) of the vehicle into thermal ( heat ) . When stepping on the brakes , the driver commands a stopping force ten times as powerful as the force that puts the car in motion . The braking system can exert thousands of pounds of pressure on each of the four brakes .The brake system is composed of the following basic components : the “master cylinder” which is located under the hood , and is directly connected to the brake pedal , converts driver foot‟s mechanical pressure into hydraulic pressure . Steel “brake lines” and flexible “brake hoses” connect the master cylinder to the “slave cylinders” located at each wheel . Brake fluid , specially designed to work in extre me condition , fills the system . “Shoes” and “Pads” are pushed by the salve cylinders to contact the “drum” and “rotors” thus causing drag , which ( hopefully ) slows the car .The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder .Stepping on the brake pedal , a plunger is actually been pushing against in the master cylinder which forces hydraulic oil ( brake fluid ) through a series of tubes and hoses to the braking unit at each wheel . Since hydraulic fluid ( or any fluid for that matter ) cannot be compressed , pushing fluid through a pipe is just like pushing a steel bar through pipe . Unlike a steel bar , however , fluid can be directed through many twists and turns on its way to its destination , arriving with the exact same motion and pressure that it started with . It is very important that the fluid is pure liquid and that there are no air bubbles in it . Air can compress , which causes a sponginess to the pedal and severely reduced braking efficiency . If air is suspected , then the system must be bled to remove the air . There are “bleeder screws” at each wheel and caliper for this purpose .On a disk brakes , the fluid from the master cylinder is forced into a caliper where it pressure against a piston . The piton , in-turn , squeezes two brake pads against the disk ( rotor ) which is attached to the wheel , forcing it to slow down or stop . This process is similar to the wheel ,causing the wheel to stop . In either case , the friction surface of the pads on a disk brake system , on the shoes on a drum brake convert the forward motion of the vehicle into heat . Heat is what causes the friction surfaces ( lining ) of the pads and shoes to eventually wear out and require replacement .Brake fluid is a special oil that has specifics properties . It is designed to withstand cold temperatures without thickening as well as very high temperatures without boiling . ( If the brake fluid should boil , it will cause you to have a spongy pedal and the car will be hard to stop ) .The brake fluid reservoir is on top of the master cylinder . Most cars today have a transparent reservoir so that you can see the level without opening the cover . The brake fluid lever will drop slightly as the brake pads wear . This is a normal condition and no cause for concern . If the lever drops noticeably over a short period of time or goes down to about two thirds full , have your brakes checked as soon as possible . Keep the reservoir covered expect for the amount of time you need to fill it and never leave a can of brake fluid uncovered . Brake fluid must maintain a very high boiling point . Exposure to air will cause the fluid to absorb moisture which will lower that boiling point .。

China Hybrid Electric Vehicle DevelopmentWith the depletion of oil resources, increase awareness of environmental protection, hybrid vehicles and electric vehicles will become the first decades of the new century, the development of mainstream cars and automobile industry become the consensusof all of the industry. The Chinese government also has the National High Technology Research and Development Program (863 Program) specifically listed, including hybrid vehicles, including electric cars of major projects. At present, China's independent innovation of new energy vehicles in the process, adhere to the government support to core technology, key components and system integration focusing on the principles established in hybrid electric vehicles, pure electric vehicles, fuel cell vehicles as a "three vertical "To vehicle control systems, motor drive systems, power battery / fuel cellfor the "three horizontal" distribution of R & D, through close links between production cooperation, China's independent innovation of hybrid cars has made significant progress.With completely independent intellectual property rights form the power system technology platform, established a hybrid electric vehicle technology development. Is the core of hybrid vehicles batteries (including battery management system) technology. In addition, also include engine technology, motor control, vehicle control technology, engine and electrical interface between the power conversion and is also the key. From the current situation, China has established a hybrid electric vehicle power system through Cooperative R & D technology platforms and systems, made a series of breakthroughs for vehicle development has laid a solid foundation. As of January 31, 2009,Technology in hybrid vehicles, China Intellectual Property Office to receive and open for the 1116 patent applications in China. In 1116 patent applications, invention 782 (authority for the 107), utility model for the 334.Mastered the entire vehicle key development, the formation of a capability to develop various types of electric vehicles. Hybrid cars in China in systems integration, reliability, fuel economy and other aspects of the marked progress in achieving fuel economy of different technical solutions can be 10% -40%.Meanwhile, the hybrid vehicle automotive enterprises and industrial R & D investment significantly enhanced, accelerating the pace of industrialization. Currently, domestic automakers have hybrid vehicles as the next major competitive products in the strategic high priority, FAW, Dongfeng, SAIC Motor, Changan, Chery, BYD, etc. have put a lot of manpower, material resources,Hybrid prototyping has been completed, and some models have achieved low-volume market.FAW GroupDevelopment Goal: By 2012, the Group plans to build an annual capacity of 11,000 hybrid cars, hybrid bus production base of 1000.FAW Group since 1999 and a new energy vehicles for theoretical research and development work, and the development of a red car performance hybrid sample. "15" period, the FAW Group is committed to the national "863" major project in the "red card in series hybrid electric vehicle research and development" mission,officially began the research and development of new energy vehicles. Beginning in 2006, FAW B70 in the Besturn, based on the technology for hybrid-based research, the original longitudinal into transverse engine assembly engine assembly, using a transverse engine and dual-motor hybrid technology. At the same time, FAW also pay close attention to the engine, mechanical and electrical integration, transmission, vehicle control networks, vehicle control systems development, the current FAW hybrid electric car has achieved 42% fuel saving effect, reached the international advanced level.Jiefang CA6100HEV Hybrid Electric BusFAW "Liberation brand CA6100HEV Hybrid Electric Bus" project is a national "863" electric vehicle major projects funded project, with pure electric drive, the engine alone drives (and charge), the joint drive motor starts the engine, and sliding regenerative braking 5 kinds of basic operation. The power hybrid electric bus and economy to the leading level, 38% fuel economy than traditional buses, emissions reduced by 30%.Red Flag CA7180AE hybrid carsRed Flag hybrid cars CA7180AE according to the national "863 Plan" is thefirst in complete with industrial prospects of the car, it is built on the basisof red car with good performance and operational smoothness.Series which is a hybrid sedan, the luxury car ,0-100km acceleration time of 14s, fuel-efficientthan traditional cars by about 50%, Euro 川emission standard.Besturn B70 hybrid carsBesturn B70 Hybrid cars using petrol - electric hybrid approach. Dual motor power system programs, mixed degree of 40/103, is all mixed (Full-Hybrid, also known as re-mixed) configurations. Besturn B70 Hybrid cars are petrol versioncosts two to three times Besturn models, mass production will be gradually reduced after the costs, even if this hybrid version Besturn market, the price certainly higher than the existing Besturn models, but high the price of petrol will not exceed 30% version of Besturn models.SAICDevelopment Goals: 2010 launch in the mixed hybrid cars, plug-in 2012, SAIC strong mix of cars and pure electric cars will be on the market.In the R & D on new energy vehicles, SAIC made clear to focus on hybrid, fuel cell for the direction, and speed up the development of alternative products. Hybrid vehicles, fuel cell vehicles, alternative fuel vehicles as a new energy strategy SAIC three key.2010 SAIC Roewe 750 hybrid cars in the mix will be put on the market, during the World Expo in Shanghai, SAIC will put 150 hybrid cars in the Expo Line on the River Run. 2012 Roewe 550 plug-in hybrid cars will be strong market, the current car's power system has been launched early development and progress.Apply the new hybrid bus moving on the 1stApply the new hybrid bus moving on the 1st Academy of Engineering by the SAIC and Shanghai Jiaotong University and other units jointly developed with independent intellectual property rights. Existing cities in the Sunwin Bus Power platform, "the new dynamic application No. 1" uses a parallel hybrid electric vehicle drive program, so that hybrid electric vehicle operating conditions in the electric air-conditioning, steering, braking and other accessoriesstill able to work without additional electric system, while use of super capacitors, to improve starting power,braking energy recovery efficiency, thereby enhancing vehicle dynamic performance, reduce fuel consumption. Car length 10m, width 2.5m, high-3.2m, can accommodate 76 people.Roewe 750 hybrid carsRoewe 750 hybrid cars in the mixed system with BSG (Belt drive start generating one machine), with "smart stop zero-emission" and "environmental protection and the power of both the" two prominent features of a top speed of 205 km / h, the maximum added driving range of up to 500 km. As for the industrialization of SAIC's first own-brand hybrid car, the Roewe 750 hybrid integrated hybrid fuel-efficient cars can achieve rates of around 20%.Dongfeng Motor GroupDevelopment Goals: Plans move into 33 billion in 10 years to develop a range of environmentally friendly hybrid vehicles, including cars.EQ7200HEV hybrid carsEQ7200HEV hybrid cars are "863" project of major projects and major strategic projects of Dongfeng Motor Corporation. The car is EQ7200-U model (Fengshen Bluebird cars) is based on an electronically controlled automatic transmission with innovative electromechanical coupling in parallel programs, configure DC brushless motor and nickel-hydrogen batteries, plans to "10 5 "during the industrialization. In dustrializatio n, the vehicle cost more tha n EQ7200 cars in crease in cost W 30%.EQ61100HEV Hybrid Electric BusEQ61100HEV electric hybrid bus by Dongfeng Vehicle Company Limited Joint Beijing Jiaotong University, Beijing, China Textile Co., Ltd. and Hunan sharp Electromechanical Technology Co., Ltd. jointly developed Shenzhou. EQ61100HEV hybrid electric bus with switched reluctance motor, Cummins ISBe1504 cylinder common rail electronic injection diesel engine, new chassis design of the system, electronically controlled automatic transmission and innovative electromechanical coupling parallel program. In the annual output reached 200, the vehicle cost more tha n the in crease in automobile engine equipped with 6CT W 30%.China ChanganDevelopment Goals: the next three years, the formation of different grades, different purposes, carry a different system of mixed platforms, weak mix of scale, strong mixed industrial R & D capabilities, covering commercial, A grade, B grade, C grade products. 2014 will achieve sales of new energy vehicles 150 000 2020 sales of new energy vehicles for more than 500,000."Eleventh Five-Year Plan" period, Chang-an increased investment in clean energy vehicles, a diversified energy technologies to carry out exploratory research. Environmental protection through energy-saving models continues to introduce new technology to lead the industry to upgrade and fully utilize and mobilize global resources,Chang'an in the middle hybrid cars, hybrid cars and other technological strength of the field are explored. Chang's first hybrid car long Anjie Xun HEV was successfully listed in June 2009; the first batch of 20 hybrid taxis Long An Zhixiang in January of this year officially put into operation in Chongqing.CheryDevelopment Goals: after 2010, more than half of Chery's products carry different levels of hybrid systems.From 2003 to 2008, mainly mixed with moderate Chery hybrid cars and energy saving system development, and industrialization; Chery in Wuhu, a taxi has been carried out on probation, fuel consumption will be reduced by 10% to 30% to reach Europe IV Standard. Since 2004, Chery hybrid cars mainly for the development of strong and industrialization. Chery hybrid car fuel consumption target to reach 100 km 3 liters, to reach Europe and the United States emissions regulations.Chery A5BSGChery A5BSG is a weak parallel hybrid electric car, using fuel engines, electric engines complementary mode, the two different power sources in the car while driving to work together or separately, through this combination to achieve the least fuel consumption and exhaust emissions, in order to achieve fuel efficiency and environmental protection purposes. Compared with the conventional car, the car in urban conditions can save 10% -15% of fuel and reduce carbon dioxide emissions by about 12%, while costs increased by only about 25% -30%.Chery A5ISGChery A5 ISG hybrid power system consists of "1.3L gasoline engine + 5-speed manual transmission +10 kW motor +144 V Ni-MH battery," the composition of the battery system used by the Johnson Controls developed "plug-in" nickel metal hydride (Ni-MH), motor with permanent magnet synchronous motor and with the motor control system, inverter and DC / DC converters. The system enables the vehicle power to 1.6L displacement level and rate of 30% fuel savings and significantly reduce the emissions of Euro V standards.Cherry A3ISGChery A3 ISG has 1.3L473F gasoline engine and equipped with 10KW motor. By gasoline engines and electric motors with torque overlay approach to dynamic mixed to provide the best vehicle power operating efficiency and energy saving environmental protection goals. Chery A3 ISG also has Stop_Restart the idling stop function such as flame start to start (BSG function), to reduce red light in the vehicle stopped or suspended when the fuel consumption and emissions expenses.FY 2BSGFY 2 BSG carry 1.5LSQR477F inline four-cylinder engine configuration BSGstart / stop and so one electric motor, red light in the vehicle stopped thedriver into the gap, it will automatically enter standby mode to turn off the engine, starting moments after the entry block automatically start the engine. FY 2 BSG vehicle average fuel consumption than the 1.5L petrol cars reduce about 5-10%, average fuel consumption can be reduced up to 15%.BYD AutoDevelopment Goal: to electric cars as a transitional mode, the electric car as the ultimate goal, the development of new energy cars BYD.BYD follow the "independent research and development, independent production, independent brand" development path, and the "core technology, vertical integration" development strategy, as the transition to dual-mode electric vehicles, electric vehicles as the ultimate goal, the development of BYD new energy vehicles.国内混合动力汽车发展随着石油资源的枯竭、人们环保意识的提高，混合动力汽车及电动汽车将成为新世纪前几十年汽车发展的主流，并成为我国汽车界所有业内人士的共识。

The Car Modeling DesignFor car modelling, mention the word people often can produce immediately for lenovo in the form of various body, although it is not comprehensive, because car styling is the sum of outside and inside modelling, but had to admit that the appearance of the car is the most intuitive impression of automobile modeling for people. For the automobile modeling design, it covers knowledge engineering technology, art and so on various aspects of the application and market demand, to meet the consumers' taste and functional requirements.Literally what is undeniable is that the car modeling design is derived from the designers of creative expression, by the designer, to many human idea about the car for a reasonable attempt, constantly breakthrough self, challenge themselves. Car modelling design, whether it's like ordinary people use of household car, or royal family use limousine, or a professional driver favorite car, sports car, they all have very obvious differentiation on modelling, the people in the street to see what level of body, the brand, to the natural identity formed certain association of owners, and for different brands of automobile modeling design, which comes from different designers for car design. Car modelling design is also on the technical support of many other disciplines, here I am to have very important influence on development of automobile modeling design of some of the subject part lists are analyze.Since the emergence of the car, bionics started inadvertently used in the design of the model. For automobile modeling, the bionic design in automobile modeling with a unique code to liberate the inherent pattern design of modelling form, interpretation of power, speed, and the symbol of status, wealth, fashion, convey the entire design concept. Nowadays, bionics become guidance and aided automobile modeling design is an important subject, bionic design also gradually become an important means of design, it not only build the people and things, harmonious coexistence between man and nature, man and society, also prompted design found a new form.Bionic design is applied to the various design very early, so see it is not surprising that, in the car on modelling is my understanding of the bionics, it is the nature of some biological characteristics of the advantages of refining of science improving applied to other industries, it is the purpose of pursuing people to draw inspiration from the biological resources, such as car early in the development of a designer to design the "fish" car, maybe at that time did not rise up the subject of bionics, but stylist inadvertently used for fish in the water received by its own size decrease in water resistance and to speed up their swimming this, and apply onto the body modelling design, more typical case is 1952 gm buick brand "fish" type design, surface modeling is very dynamic, because the car interior ministry wide, wide field of vision, both passengers and drivers, inside the body will feel carefree, the affinity of car body itself has an irresistible, should allowstereotyped monotonous straight line in car design, is also a very important breakthrough at the time.There are a lot of examples, such as "viper" is a sports car, as America's most ferocious snake - "viper", has the characteristics of all nature disaster. "Viper" series of models, as a breakthrough point, the appearance of modelling design in particular the sharp front face and the spirit of the headlamps, give a person with terrible ferocity, good at dueling sensory stimulation, like soldiers courageous warrior, always ready to fight to the death, embodies the human eternal pursuit of the meaning of life. Viper, the second generation of 9 models, convey the intrinsic well. Automobile modeling bionic design with "from nature to the nature", as has been the pursuit of goals, the application of natural biological form surface is limited modelling space into endless spiritual awareness, create a bionic form of aesthetic value, to achieve the "personalized" demand and the state of "imitating the nature". Can reference on modelling human nature, The Times on the automobile modeling application development gradually, it seems to me is not only on the auto industry development and progress, is more of a human can live in the actual production of respecting nature, respect nature, from the development of bionics in the automobile modeling design process I can read the industry further development, it is also because modelling are close to the essence of life itself.Automobile modeling design purpose lies in the combination offunction and form aesthetic feeling, to give users in a certain emotional factors influence or impact on the market, on modelling design, different automobile modeling can bring a person different emotional experience, and to convey the designer wants to make people get on a car design.Automobile modeling design is applied art gimmick science express car function, structure and texture, and make people for its beauty. Automobile modeling design must reflect the style of the vehicle, such as streamlined can indicate the car has a higher speed, so as to shape a sporty image in the consumers' mind. Carbon fiber material can reflect the high-tech feeling and lightness of car, has a muscular body form can express powerful and protection of security. Excellent automobile modeling design can make consumers by aesthetic appreciation to deep understanding of its meaning, to produce the desire of the product. This is based on the perceptual technology this is not by many cognitive developed from cognitive psychology on the subject's important role on the automobile modeling design. It is stylist will be collected from the market information, through the analysis of consumer psychology that design more accord with human aesthetic and functional requirements of product evolutionary design, stylist is in perceptual information, consumer psychology and rational constraints (engineering) between coordination.In automobile product development model of "user as the center" in the early stage of the design need to study consumer's perceptual demand, andconsumers to seek in the perceptual demand often from the image of the car. Such as businessman to give reliable partners to form the image of good faith, the car for business occasions, modelling is generally very grave, composed, atmosphere; Racing car, for example, has very obvious streamline on modelling design, in order to display the car performance is strong, can run very fast, with enough instances of racer; Cultural entertainment venue such as car again, the modelling is compared commonly lively, fashion, have individual character, to show the meeting activities and the characteristics of representative. These are the perceptual technology on automobile modeling design is applied to car use and the appreciation of the most common level.Automobile modeling are actually very close to our daily life, on the streets everywhere the family car, taxi, bus, sometimes even see a cable car, luxury cars, sports car, saloon car. We have a lot of focus on automobile brand rather than modelling. But nature sense, any brand of car has its unique style of the modelling, we are to determine the brand car with its shape characteristics, such as seen in the street a lamborghini, its streamline appearance alone, we will be able to determine that it is lamborghini car, this is the car model represented by the car culture connotation. At the end of this course, the reason I chose to automobile modeling design analysis for class papers, but also for any automobile modeling design, as far as I'm concerned, is the designer of some design ideas of cultural interpretation,any design is necessarily comes from life, no experience and observation, can't make the products can be accepted by the public. Automobile modeling is not only the appearance, also is not only a decoration, interior space how to start from the Angle of human nature, and so on these elements are necessarily involve automobile modeling. So this is a worthy art, technology and market coordination aspects of creative achievement, no matter from what Angle to design the vehicle model, the ultimate goal is to continuously improve to meet the needs of users of the product.汽车造型设计对于汽车造型，提到这个词时人们往往能立即产生对于各种车身形态的联想，虽然它并不全面，因为汽车造型是汽车外部和车厢内部造型的总和，但不得不承认的是，汽车的外观的确是人们对于汽车造型的最直观印象。

Ultrasonic ranging system designPublication title: Sensor Review. Bradford: 1993.Vol.ABSTRACT: Ultrasonic ranging technology has wide using worth in many fields, such as the industrial locale, vehicle navigation and sonar engineering. Now it has been used in level measurement, self-guided autonomous vehicles, fieldwork robots automotive navigation, air and underwater target detection, identification, location and so on. So there is an important practicing meaning to learn the ranging theory and ways deeply. To improve the precision of the ultrasonic ranging system in hand, satisfy the request of the engineering personnel for the ranging precision, the bound and the usage, a portable ultrasonic ranging system based on the single chip processor was developed.Keywords: Ultrasound, Ranging System, Single Chip Processor1. IntroductiveWith the development of science and technology, the improvement of people’s standard of living, speeding up the development and construction of the city. Urban drainage system have greatly developed their situation is construction improving. However, due to historical reasons many unpredictable factors in the synthesis of her time, the city drainage system. In particular drainage system often lags behind urban construction. Therefore, there are often good building excavation has been building facilities to upgrade the drainage system phenomenon. It brought to the city sewage, and it is clear to the city sewage and drainage culvert in the sewage treatment system.Co mfort is very important to people’s lives. Mobile robots designed to clear the drainage culvert and the automatic control system Free sewage culvert clear guarantee robots, the robot is designed to clear the culvert sewage to the core. Control system is the core component of the development of ultrasonic range finder. Therefore, it is very important to design a good ultrasonic range finder.2. A principle of ultrasonic distance measurementThe application of AT89C51:SCM is a major piece of computer components are integrated into the chip micro-computer. It is a multi-interface and counting on the micro-controller integration, and intelligence products are widely used in industrial automation. and MCS-51 microcontroller is a typical and representative.Microcontrollers are used in a multitude of commercial applications such as modems, motor-control systems, air conditioner control systems, automotive engine and among others. The high processing speed and enhanced peripheral set of these microcontrollers make them suitable for such high-speed event-based applications. However, these critical application domains also require that these microcontrollers are highly reliable. The high reliability and low market risks can be ensured by a robust testing process and a proper tools environment for the validation of these microcontrollers both at the component and at the system level. Intel Plaform Engineering department developed an object-oriented multi-threaded test environment for the validation of its AT89C51 automotive microcontrollers. The goals of this environment was not only to provide a robust testing environment for the AT89C51 automotive microcontrollers, but to develop an environment which can be easily extended and reused for the validation of several other future microcontrollers. The environment was developed in conjunction with Microsoft Foundation Classes(AT89C51).1.1 Features* Compatible with MCS-51 Products* 2Kbytes of Reprogrammable Flash MemoryEndurance: 1,000Write/Erase Cycles* 2.7V to 6V Operating Range* Fully Static operation: 0Hz to 24MHz* Two-level program memory lock* 128x8-bit internal RAM* 15programmable I/O lines* Two 16-bit timer/counters* Six interrupt sources*Programmable serial UART channel* Direct LED drive output* On-chip analog comparator* Low power idle and power down modes1.2 DescriptionThe AT89C2051 is a low-voltage, high-performance CMOS 8-bit microcomputer with 2Kbytes of flash programmable and erasable read only memory (PEROM). The device is manufactured using Atmel’s high density nonvolatile memory technology and is compatible with the industry standard MCS-51 instruction set and pinout. By combining a versatile 8-bit CPU with flash on a monolithic chip, the Atmel AT89C2051 is a powerful microcomputer which provides a highly flexible and cost effective solution to many embedded control applications.The AT89C2051 provides the following standard features: 2Kbytes of flash,128bytes of RAM, 15 I/O lines, two 16-bit timer/counters, a five vector two-level interrupt architecture, a full duplex serial port, a precision analog comparator, on-chip oscillator and clock circuitry. In addition, the AT89C2051 is designed with static logicfor operation down to zero frequency and supports two software selectable power saving modes. The idle mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt system to continue functioning. The power down mode saves the RAM contents but freezer the oscillator disabling all other chip functions until the next hardware reset.1.3 Pin Configuration1.4 Pin DescriptionVCC Supply voltage.GND Ground.Prot 1Prot 1 is an 8-bit bidirectional I/O port. Port pins P1.2 to P1.7 provide internal pullups. P1.0 and P1.1 require external pullups. P1.0 and P1.1 also serve as the positive input (AIN0) and the negative input (AIN1), respectively, of the on-chip precision analog comparator. The port 1 output buffers can sink 20mA and can drive LED displays directly. When 1s are written to port 1 pins, they can be used as inputs. When pins P1.2 to P1.7 are used as input and are externally pulled low, they will source current (IIL) because of the internal pullups.Port 3Port 3 pins P3.0 to P3.5, P3.7 are seven bidirectional I/O pins with internal pullups. P3.6 is hard-wired as an input to the output of the on-chip comparator and is not accessible as a general purpose I/O pin. The port 3 output buffers can sink 20mA. When 1s are written to port 3 pins they are pulled high by the internal pullups and can be used as inputs. As inputs, port 3 pins that are externally being pulled low will source current (IIL) because of the pullups.Port 3 also serves the functions of various special features of the AT89C2051 as listed below.1.5 Programming the FlashThe AT89C2051 is shipped with the 2 Kbytes of on-chip PEROM code memory array in the erased state (i.e., contents=FFH) and ready to be programmed. The code memory array is programmed one byte at a time. Once the array is programmed, to re-program any non-blank byte, the entire memory array needs to be erased electrically.Internal address counter: the AT89C2051 contains an internal PEROM address counter which is always reset to 000H on the rising edge of RST and is advanced applying a positive going pulse to pin XTAL1.Programming algorithm: to program the AT89C2051, the following sequence is recommended.1. power-up sequence:Apply power between VCC and GND pins Set RST and XTAL1 to GNDWith all other pins floating , wait for greater than 10 milliseconds2. Set pin RST to ‘H’ set pin P3.2 to ‘H’3. Apply the appropriate combination of ‘H’ or ‘L’ logic to pins P3.3, P3.4, P3.5,P3.7 to select one of the programming operations shown in the PEROM programming modes table.To program and Verify the Array:4. Apply data for code byte at location 000H to P1.0 to P1.7.5.Raise RST to 12V to enable programming.5. Pulse P3.2 once to program a byte in the PEROM array or the lock bits. The byte-write cycle is self-timed and typically takes 1.2ms.6. To verify the programmed data, lower RST from 12V to logic ‘H’ level and set pins P3.3 to P3.7 to the appropriate levels. Output data can be read at the port P1 pins.7. To program a byte at the next address location, pulse XTAL1 pin once to advance the internal address counter. Apply new data to the port P1 pins.8. Repeat steps 5 through 8, changing data and advancing the address counter for the entire 2 Kbytes array or until the end of the object file is reached.9. Power-off sequence: set XTAL1 to ‘L’ set RST to ‘L’Float all other I/O pins Turn VCC power off2.1 The principle of piezoelectric ultrasonic generatorPiezoelectric ultrasonic generator is the use of piezoelectric crystal resonators to work. Ultrasonic generator, the internal structure as shown, it has two piezoelectric chip and a resonance plate. When it’s two plus pulse signal, the frequency equal to the intrinsic piezoelectric oscillation frequency chip, the chip will happen piezoelectric resonance, and promote the development of plate vibration resonance, ultrasound is generated. Conversely, it will be for vibration suppression of piezoelectric chip, the mechanical energy is converted to electrical signals, then it becomes the ultrasonic receiver.The traditional way to determine the moment of the echo’s arrival is based on thresholding the received signal with a fixed reference. The threshold is chosen well above the noise level, whereas the moment of arrival of an echo is defined as the first moment the echo signal surpasses that threshold. The intensity of an echo reflecting from an object strongly depends on the object’s nature, size and distance from the sensor. Further, the time interval from the echo’s starting point to the moment when it surpasses the threshold changes with the intensity of the echo. As a consequence, a considerable error may occur even two echoes with different intensities arriving exactly at the same time will surpass the threshold at different moments. The stronger one will surpass the threshold earlier than the weaker, so it will be considered as belonging to a nearer object.2.2 The principle of ultrasonic distance measurementUltrasonic transmitter in a direction to launch ultrasound, in the moment to launch the beginning of time at the same time, the spread of ultrasound in the air, obstacles on his way to return immediately, the ultrasonic reflected wave received by the receiverimmediately stop the clock. Ultrasound in the air as the propagation velocity of 340m/s, according to the timer records the time t, we can calculate the distance between the launch distance barrier(s), that is: s=340t / 23. Ultrasonic Ranging System for the Second Circuit DesignSystem is characterized by single-chip microcomputer to control the use of ultrasonic transmitter and ultrasonic receiver since the launch from time to time, single-chip selection of 875, economic-to-use, and the chip has 4K of ROM, to facilitate programming.3.1 40 kHz ultrasonic pulse generated with the launchRanging system using the ultrasonic sensor of piezoelectric ceramic sensorsUCM40, its operating voltage of the pulse signal is 40kHz, which by the single-chip implementation of the following procedures to generate.puzel: mov 14h, # 12h; ultrasonic firing continued 200msHere: cpl p1.0; output 40kHz square wavenop;nop;nop;djnz 14h, here;retRanging in front of single-chip termination circuit P1.0 input port, single chip implementation of the above procedure, the P1.0 port in a 40kHz pulse output signal, after amplification transistor T, the drive to launch the first ultrasonic UCM40T, issued 40kHz ultrasonic pulse, and the continued launch of 200ms. Ranging the right and the left side of the circuit, respectively, then input port P1.1 and P1.2, the working principle and circuit in front of the same location.3.2 Reception and processing of ultrasonicUsed to receive the first launch of the first pair UCM40R, the ultrasonic pulse modulation signal into an alternating voltage, the op-amp amplification IC1A and after polarization IC1B to IC2. IC2 is locked loop with audio decoder chip LM567, internal voltage-controlled oscillator center frequency of f0=1/1.1R8C3, capacitor C4 determinetheir target bandwidth. R8-conditioning in the launch of the high jump 8 feet into a low-level, as interrupt request signals to the single-chip processing.Ranging in front of single-chip termination circuit output port INT0 interrupt the highest priority, right or left location of the output circuit with output gate IC3A access INT1 port single-chip, while single-chip P1.3 and P1.4 received input IC3A, interrupted by the process to identify the source of inquiry to deal with, interrupt priority level for the first left right after. Part of the source code is as follows:Receivel: push pswpush accclr ex1; related external interrupt 1jnb p1.1, right; P1.1 pin to 0, ranging from right to interrupt service routine circuitjnb p1.2, left; P1.2 pin to 0, to the left ranging circuit interrupt service routinereturn: SETB EX1; open external interrupt 1pop accpop pswretiright: …; right location entrance circuit interrupt service routineAjmp Returnleft: …; left ranging entrance circuit interrupt service routineAjmp Return3.3 The calculation of ultrasonic propagation timeWhen you start firing at the same time start the single-chip circuitry within the timer T0, the use of timer counting function records the time and the launch of ultrasonic reflected wave received time. When you receive the ultrasonic reflected wave, the receiver circuit output a negative jump in the end of INT0 or INT1 interrupt request generates a signal, single-chip microcomputer in response to external interrupt request, the implementation of the external interrupt service subroutine, read the time difference, calculating the distance. Some of its source code is as follows:RECEIVE0: PUSH PSWPUSH ACCCLR EX0; related external interrupt 0MOV R7, TH0; read the time valueMOV R6, TL0CLR CMOV A, R6SUBB A, #0BBH; calculate the time differenceMOV 31H, A; storage resultsMOV A, R7SUBB A, # 3CHMOV 30H, ASETB EX0; open external interrupt 0\POP ACCPOP PSWRETIFor a flat target, a distance measurement consists of two phases: a coarse measurement and a fine measurement:Step 1: Transmission of one pulse train to produce a simple ultrasonic wave.Step 2: Changing the gain of both echo amplifiers according to equation, until the echo is detected.Step 3: Detection of the amplitudes and zero-crossing times of both echoes.Step 4: Setting the gains of both echo amplifiers to normalize the output at, say 3 volts. Setting the period of the next pulses according to the: period of echoes. Setting the time window according to the data of step 2.Step 5: Sending two pulse trains to produce an interfered wave. Testing the zero-crossing times and amplitudes of the echoes. If phase inversion occurs in the echo, determine to otherwise calculate to by interpolation using the amplitudes near the trough. Derive t sub m1 and t sub m2.Step 6: Calculation of the distance y using equation.4、The ultrasonic ranging system software designSoftware is divided into two parts, the main program and interrupt service routine. Completion of the work of the main program is initialized, each sequence of ultrasonic transmitting and receiving control.Interrupt service routines from time to time to complete three of the rotation direction of ultrasonic launch, the main external interrupt service subroutine to read the value of completion time, distance calculation, the results of the output and so on.5、ConclusionsRequired measuring range of 30cm-200cm objects inside the plane to do a number of measurements found that the maximum error is 0.5cm, and good reproducibility. Single-chip design can be seen on the ultrasonic ranging system has a hardware structure is simple, reliable, small features such as measurement error. Therefore, it can be used not only for mobile robot can be used in other detection system.Thoughts: As for why the receiver do not have the transistor amplifier circuit, because the magnification well, integrated amplifier, but also with automatic gain control level, magnification to 76dB, the center frequency is 38k to 40k, is exactly resonant ultrasonic sensors frequency.6、Parking sensor6.1 Parking sensor introductionReversing radar, full name is "reversing the anti-collision radar, also known as" parking assist device, car parking or reversing the safety of assistive devices, ultrasonic sensors(commonly known as probes), controls and displays (or buzzer)and other components. To inform the driver around the obstacle to the sound or a moreintuitive display to lift the driver parking, reversing and start the vehicle around tovisit the distress caused by, and to help the driver to remove the vision deadends and blurred vision defects and improve driving safety.6.2 Reversing radar detection principleReversing radar, according to high-speed flight of the bats in thenight, not collided with any obstacle principles of design anddevelopment. Probe mounted on the rear bumper, according to different price and brand, the probe only ranging from two, three, four, six, eight,respectively, pipe around. The probe radiation, 45-degree angle up and downabout the search target. The greatest advantage is to explore lower than the bumper of the driver from the rear window is difficult to see obstacles, and the police, suchas flower beds, children playing in the squatting on the car.Display parking sensor installed in the rear view mirror, it constantlyremind drivers to car distance behindthe object distance to the dangerous distance, the buzzer starts singing, allow the driver to stop. When the gear lever linked into reverse gear, reversing radar, auto-start the work, the working range of 0.3 to 2.0 meters, so stop when the driver was very practical. Reversing radar is equivalent to an ultrasound probe for ultrasonic probe can be divided into two categories: First, Electrical, ultrasonic, the second is to use mechanical means to produce ultrasound, in view of the more commonly used piezoelectric ultrasonic generator, it has two power chips and a soundingboard, plus apulse signal when the poles, its frequency equal to the intrinsic oscillation frequency of the piezoelectric pressure chip will be resonant and drivenby the vibration of the sounding board, the mechanical energy into electrical signal, which became the ultrasonic probe works. In order to better study Ultrasonic and use up, people have to design and manufacture of ultrasonic sound, the ultrasonic probe tobe used in the use of car parking sensor. With this principle in a non-contactdetection technology for distance measurement is simple, convenient and rapid, easyto do real-time control, distance accuracy of practical industrial requirements. Parking sensor for ranging send out ultrasonic signal at a givenmoment, and shot in the face of the measured object back to the signal wave, reversing radar receiver to use statistics in the ultrasonic signal from the transmitter to receive echo signals calculate the propagation velocity in the medium, which can calculate the distance of the probe and to detect objects.6.3 Reversing radar functionality and performanceParking sensor can be divided into the LCD distance display, audible alarm, and azimuth directions, voice prompts, automatic probe detection function is complete, reversing radar distance, audible alarm, position-indicating function. A good performance reversing radar, its main properties include: (1) sensitivity, whether theresponse fast enough when there is an obstacle. (2) the existence of blind spots. (3) detection distance range.6.4 Each part of the roleReversing radar has the following effects: (1) ultrasonic sensor: used tolaunch and receive ultrasonic signals, ultrasonic sensors canmeasure distance. (2) host: after the launch of the sine wave pulse to the ultrasonic sensors, and process the received signal, to calculate the distance value, the data and monitor communication. (3) display or abuzzer: the receivinghost from the data, and display the distance value and provide differentlevels according to the distance from the alarm sound.6.5 Cautions1, the installation height: general ground: car before the installation of 45 ~55: 50 ~ 65cmcar after installation. 2, regular cleaningof the probe to prevent the fill. 3, do not use the hardstuff the probe surface cover will produce false positives or ranging allowed toprobe surface coverage, such as mud. 4, winter to avoid freezing. 5, 6 / 8 probe reversing radar before and after the probe is not free to swap may cause the ChangMing false positive problem. 6, note that the probe mounting orientation, in accordance with UP installation upward. 7, the probe is not recommended to install sheetmetal, sheet metal vibration will cause the probe resonance, resulting in false positives.超声测距系统设计原文出处：传感器文摘布拉福德：1993年超声测距技术在工业现场、车辆导航、水声工程等领域具有广泛的应用价值，目前已应用于物位测量、机器人自动导航以及空气中与水下的目标探测、识别、定位等场合。

外文文献原稿和译文原稿A New Type Car -- Hybrid Electric VehicleWith skyrocketing fuel prices and changes in weather patterns, many car manufacturers claimed to develop the kind of vehicles that will increase the mileage and reduce the emissions. Hybrid car is a kind of vehicle which can meet above requirements. A hybrid car features a small fuel-efficient gas engine combined with an electric motor that assists the engine.The reasons of building such a complicated machine are twofold: to reduce tailpipe emissions and to improve mileage. Firstly, hybrid cars are good for the environment. They can reduce smog by 90 percent and they use far less gasoline than conventional cars. Meanwhile, hybrid cars burn less gasoline per mile, so they release fewer greenhouse gases. Secondly, hybrid cars are economical. Hybrid cars, which run on gas and electricity, can get up to 55 to 60 miles per gallon in city driving, while a typical SUV might use three times as much gas for the same distance! There are three reasons can mainly account for that: 1) Hybrid engines are much smaller than those on conventional cars. A hybrid car engine is to accommodate the 99% of driving time when a car is not going up hills or accelerating quickly. When extra acceleration power is needed, it relies on the battery to provide additional force. 2) Hybrid gasoline engine can shut off when the car is stopped and run off their electric motor and battery.3) Hybrid cars often recover braking energy. Electric motors could take the lost kinetic energy in braking and use it to charge the battery. Furthermore, hybrids are better than all-electric cars because hybrid car batteries recharge as you drive so there is no need to plug in. Most electric cars need to be recharged every 50-100miles. Also, most electric cars cannot go faster than 50-60 mph, while hybrids can.Hybrid cars bridge the gap between electric and gasoline-powered cars by traveling further and driving faster and hybrid gas-electric cars are proving to be a feasible alternative at a time of high gas prices. So, in my opinion, hybrid cars will have a bright future.How Does Hybrid Electric Vehicle Work？You probably own a gasoline or diesel-engine car. You may have heard of electric vehicles too. A hybrid vehicle or hybrid electric vehicle (HEV) is a combination of both. Hybrid vehicles utilize two or more sources of energy for propulsion. In the case of HEVs, a combustion engine and an electric motor are used.How it works depends on the type of drive train it has. A hybrid vehicle can either have a parallel or series or parallel-series drive train.Parallel HybridThe parallel hybrid car has a gas tank, a combustion engine, transmission,electric motor, and batteries.A parallel hybrid is designed to run directly from either the combustion engine or the electric motor. It can run using both the engine and the motor. As a conventional vehicle, the parallel hybrid draws its power from the combustion engine which will then drive the transmission that turns the wheels. If it is using the electric motor, the car draws its power from the batteries. The energy from the batteries will then power the electric motor that drives the transmission and turns the wheel.Both the combustion engine and the electric motor are used at the same time during quick acceleration, on steep ascend, or when either the engine or the motor needs additional boost.Since the engine is directly connected to the wheels in a parallel drive train, it eliminates the inefficiency of converting mechanical energy into electrical energy and back. This makes a very effective vehicle to drive on the highway.Series HybridThe series hybrid car also has a gas tank, a combustion engine, transmission, electric motor, and batteries with the addition of the generator. The generator can be the electric motor or it can be another separate component.The series configuration is the simplest among the 3. The engine is not connected to the transmission rather it is connected to the electric motor. This means that the transmission can be driven only by the electric motor which draws its energy from the battery pack, the engine or the generator.A hybrid car with a series drive train is more suited for city driving conditions since the engine will not be subjected to the varying speed demands (stop, go, and idle) that contributes to fuel consumption.Series-Parallel HybridThe series-parallel configuration solves the individual problems of the parallel and series hybrid. By combining the 2 designs, the transmission can be directly connected to the engine or can be separated for optimum fuel consumption. The Toyota Prius and the Ford Escape Hybrid use this technology.Honda’s hybridFor those of you who have toyed with the idea of buying a hybrid but were discouraged by the price, you are not alone. In fact, despite the growing concern for the environment, not to mention the skyrocketing price of gas, hybrid cars still only represent a small percentage of global car sales, and a major reason for this is the cost.Hybrids are considered the wave of the future because they not only reduce emissions, addressing the issue of climate change, but they get great gas mileage, an important consideration with the current price of oil. It should be noted that hybrids can also improve the power of the engine, which compromises any advantages in fuel efficiency and emissions. Whatever the application, however, the technology makes the cars more expensive.Because of this, they are the vehicle of choice for only a small niche of people who can afford them, and they currently enjoy a special status amongst the image conscious celebrity-set. For most average consumers, however, they are not an option.That may soon change.Honda Motor Corporation, one of the largest car manufacturers in the world and a leader in fuel efficient technology, has unveiled it’s plan to introduce a low-cost hybrid by 2009. If they can pull it off, they hope to make the hybrid a more mainstream car that will be more appealing to the general public, with the ultimate goal of achieving greater sales and broader appeal than their current incarnation.This, of course, is making Detroit nervous, and may signal a need for American car makers to start making greener and more fuel efficient vehicles, something they could afford to ignore in the past because hybrid cars weren’t worth their attention (due to such a small market share) while gas-guzzling SUVs have such high profit margins.Honda, meanwhile, has had to confront a growing need to compete with Toyota, which has not only grown to be the world’s largest automaker, but makes the car that has become synonymous with the hybrid movement, the Prius. Honda is therefore faced with the seemingly insurmountable task of challenging Toyota’s dominance in the market.Concurrently, Toyota is racing to lower production costs on the Prius, as well, which would hopefully result in a lower cost to the consumer. All eyes are on a potentially favorable car buyers market in 2009.In the meantime, with even adamant global warming naysayers warming up (no pun intended) to the possibilities of an ecological disaster on the horizon, maybe it’s time that we got over our need to drive huge SUVs and start moderating our fuel consumption.Then again, as gas prices hovering around $4.00 and with no ceiling in sight, we may have little choice in the matter.Engine Operating PrinciplesMost automobile dngines are internal combustion, reciprocating 4-stroke gasoline engines, but other types have been used, including the diesel, the rotary ( Wankel ) , the 2-srtoke, and stratified charge.Reciprocating means up and down or banck and forth, It is the up and down action of a piston in the cylinder blick, or engine block. The blick is an iron or aluminum casting that contains engine cylinders and passges called water jackets for coolant circulation. The top of the block is covered with the cylinder head. Which forms the combustion chanber. The bottom of the block is covered with an oil pan or oil sump.Power is produced by the linear motion of a piston in a cylinder. However, this linear motion must be changed into rotary motion to turn the wheels of cars of trucks. The piston is attached to the top of a connecting rod by a pin, called a piston pin or wrist pin. The bottom of the connecting rod is attached to the crankshaft. The connecting rod transmits the up-and-down motion of the piston to the crankshaft, which changes it into rotary motion.The connecting rod is mounted on the crankshaft with large beaings called rodbearings. Similar bearings, called main bearings, are used to mount the crankshaft in the block. Shown in Fig. 1-1The diameter of the cylinder is called the engine bore. Displacement and compression ratio are two frequently used engine specifications. Displacement indicates engine size, and compression ratio compares the total cylinder volume to compression chamber volume.The term stroke is used to describe the movement of the iston within the cylinder, as well as the distance of piston travel. Depending on the type of engine the operating cycle may require either two or four strokes to complete. The 4-stroke engine is also called Otto cycle engine, in honor of the German engineer, Dr. Nikolaus Otto, who first applied the principle in 1876. In the 4-stroke engine, four strokes of the piston in the cylinder are required to complete one full operating cycle. Each stroke is named after the action it performs intake, compression, power, and exhaust in that order, shown in Fig1-2.1、Intake strokeAs the piston moves down, the vaporized mixture of fuel and air enters the cylinder through open intake valve. To obtain the maximum filling of the cylinder the intake valve opens about 10°before t.b.c., giving 20°overlap. The inlet valve remains open until some 50°after b.d.c. to take advantage of incoming mixture.2、 Compression strokeThe piston turns up, the intake valve closes, the mixture is compressed within the combustion chamber, while the pressure rise to about 1Mpa, depending on various factors including the compression ratio, throttle opening and engine speed. Near the top of the stroke the mixture is ignited by a spark which bridges the gap of the spark plug.3、 Power strokeThe expanding gases of combustion produces a rise in pressure of the gas to some 3.5Mpa, and the piston is forced down in the cylinder. The exhaust valve opens near the bottom of the stroke.4、Exhust strokeThe piston moves back up with the exhaust valve open some 50°before b.d.d., allowing the pressure within the cylinder to fall and to reduce ‘back’pressure on the piston during the exhaust stroke, and the burned gases are pushed out to prepare for the next intake stroke.The intake valve usually opens just before the exhaust stroke. This 4-stroke cycle is continuously repeared in every as long as the engineremains running.A 2-stroke engine also goes through four actions to complete one operating cycle.However, the intake and the compression actions are combined in one seroke, and the power and exhaust actions are combined in the other stroke. The term2-stroke cycle or 2-stroke is preferred to the term 2-cycle, which is really not accurate.In automobile engines, all pistons are attached to a single crankshaft. The more cylinders an engine has, the more power strokes produced for cach revolution. This means that an 8-cylinder engine runs more smoothly bdcause the power atrokes arecloser together in time and in degrees of engine rotation.The cylinders of multi-cylinder automotive engines arranged in one of three ways. 1、Inline engines use a single block of cylinder.Most 4-cylinder and any 6-cylinder engines are of this design. The cylinders do not have to be vertical. They can be inclined either side.2、V-type engines use two equal bands of cylinders, usually inclined 60degrees or 90degrees from the cach other. Most V-type engines have 6 or 8 cylinders, although V-4 and V-12 engines have been built.3、Horizontally opposed or pancake engines have two equal banks of cylinders 180degreeas apart. These space saving engine designs are often air-cooled, and are found in the Chevrolet Carvair, Porsches, Subaus, and V olkswagens. Subaus design is liquid cooled.Late-model V olkswagen vans use a liquid-cooled version of the air cooled VWhorizontally opposed engine.译文新型汽车----混合动力汽车在油价飞涨的今天，汽车制造商被要求发展一种排放低，行驶里程长的汽车。

Automotive MarketingFirst, the auto parts network management conceptAmerican auto parts of automobile fittings dealer Raymond is located in a suburban Atlanta, American and other accessories, this shop to shop and its characteristics, but is online transactions, and car accessories sales related services are available on the Internet. This distributior store of salespeople have extensive network of knowledge, they patiently helped no online trading experience of customer finish on the Internet. If the customer need, they also can be free of imparting knowledge of online transactions. In order to reflect the rapid and convenient online sales, they provide 24-hour services, if the customer questions, they always strive to reply in 15 minutes. The customer need, sitting at home before entering the store sells computer, then the website can complete all want to do, watch shop fittings, download the pictures, auto prices, orders, etc. Then, you can sit at home or in his own maintenance shop of door-to-door salesman received by car accessories.Online transaction does have many advantages. To save time, this is obvious. In this way, said dealers trade become a way to attract customers, people gradually accept it and approved. At the same time, the online trading reduced many expenses, including the staff, management, marketing, etc, and save the cost of expenses on auto parts price on the customer benefit.This is the foreign auto accessories sales of a networked management. This through the Internet and e-commerce fulfillment of our country, and online business, the auto parts marketing MVP has important significance. From the current situation of auto parts, auto sales network throughout the circulation of construction is not perfect, or in an internal network condition. The network Settings are mostly for enterprise internal coordination and daily management, instead of e-commerce.China's online accessories sales prospects from abroad, also can be the development of auto parts online sales of enlightenment. In the foreign auto accessories sales, how to do? "" zero kilometers sales How to provide the most satisfactory service to customers? With the Internet, these two problems can greatly alleviate. Now, especially developed countries around the world through the Internet to buy auto accessories are expanding quickly.Second, the auto parts network management advantagesOnline purchase of auto parts for car dealers and customers, whether for auto parts manufacturing enterprise, it is a good thing. First, for auto parts manufacturing enterprise, the Internet can more easily collect customers to buy auto parts in the process of the various issues, and timely information feedback to the auto parts manufacturing enterprises. According to the above analysis, the enterprise can produce customer purchase intention, thus producing according with market demand as the auto parts. This saves time and cost, and snatch market opportunities. Secondly, the use of Internet information and convenient services, manufacturing enterprises can promptly informed accessories vendors inventory and sales, thereby adjusting their production and auto parts allocation plan. Auto accessories vendors reduce inventory, accelerate the cash flow, obtained satisfactory returns. For users, they can through the Internet, like "menu" optional choose oneself need auto parts.The market information for auto parts manufacturing enterprise and the seller is important, and can be easily obtained through the Internet. Internet auto parts vendors canprovide customers to production enterprise of real-time field information. The demand of information can help to reduce automobile accessories sales production enterprise charges, which usually cost will account for auto parts price of around 15% final sales. If the promotion costs, the cost is higher proportion. In fact, the Internet can also play a role of advertising.Before that, the sellers of auto parts distribution has always sold in part, and another part of the poor. Money is part of the occupied fee is caused to sell the car accessories. Through the Internet, the production enterprises and vendors can be avoided in production and sales market sales bad auto parts. With the advent of the Internet and convenient service, not only saves time and cost, and more importantly, the Internet can cause a concept of change, auto parts manufacturing enterprise, distributors and customers to be stuck nearlier more.Third, China's automobile fittings network management development trendChina's auto accessories network management and e-commerce, has started to present development trend. Many of the current domestic large and medium-sized car repair enterprises established computer management system, realized the internal network. This covers the entire network maintenance services. To receive from business, dispatching material inspection. Computerized control can be made to understand the undertakings in real-time monitoring, which can form, and greatly improve the efficiency of the staff, more important is to replace manual accounting and management, strengthen accessories.Meanwhile, some large scale, the current operating performance good car accessories dealers also introduced a computerized management. Because of automotive products, so use variety of such management software, the personnel must be higher requirements after a period of training to mount guard. Such auto parts management network covers the whole process of operation. From the incoming, retail and wholesale price is determined according to the models, and such Numbers classified management, finally to do account settlement and delivery, and XiaoZhang. Chain-like management make better dealer has put the network management of the whole FenXiaoDian to it, formed a certain scale of network connection. Many automobile fittings all dealers from network management gained good returns. The most prominent feature is reflected in the commodity, through the network management allocations, can reach twice the result with half the effort.In addition, in recent years the old car accessories circulation system gradually broken, auto parts market, constantly mature vigorous development. Some far-sighted insight, the operator has felt the network era, and start a near the market network. Like changchun automobile fittings, west of Beijing automobile fittings, Shanghai auto parts market such as the city of virtual network construction and the development of the market for 2000. But the reality is that the network is quite childish, but certainly not realize online trading and service.With the quickening pace of "two", the personage inside course of study to commend "trinity" sales mode in the earth gradually. For example, in the choice of Shanghai general dealers, whether to have "trinity" sales ability to determine the object, such as a "trinity" whole car accessories sales mode is a microcosm of network flow field. Because it includes from truckload sale, spare parts supply and maintenance.Mention auto parts network management and e-commerce, somebody thinks, car accessories telephone shopping is actually e-commerce, because only communicationplatform between different, the operation is basically the same. Actually this kind of understanding is not accurate, phone business and e-commerce is more like Cousins, in many ways, phone business congenital deficiency. First, consumers from the phone in understanding the information is limited, can fully satisfy customer's requirements. Secondly, if advertisers, or printing accessories for customers, due to the directory of accessories sales, cost of printing more and more high, but slow renewal speed. In addition, on the telephone exchanges, due to the environment, voice, speaking, the influence of factors, make telephone service personnel difficulty and error rates increased. Just as phone business, management content in depth and breadth aspect further development will be limited.Fourth,Auto parts distribution system and network management of constructionAuto parts distribution system and network management of construction iis now a successful online trading tangible products such as books, audio and video products, clothing, etc., and auto parts as a certain scientific and technological content, some products are statemandatory standard industrial products, to achieve on-line transactions, compared with other industrial products, have their advantages, sellers and buyers as long as posted on the Internet and input information about auto parts, such as vehicles, cars, parts name, part number, manufacture, price, quantity, etc., you can sell online or purchase.To truly realize the concept of e-commerce online sales, buyers and sellers in addition to solving the "integrity" issues, but also must establish a complete set of efficient logistics distribution system.Speaking before the factors that limit development of electronic commerce, nothing more than a means of payment, security authentication, the real make up, will find car parts logistics and distribution system is the most difficult, the most facile, the most expensive one.Many auto parts e-commerce companies are trying to find the existing physical network, such as postal services, courier and even newspaper delivery company as a delivery system.However, a suitable auto parts distribution and e-commerce system should look like?The conditions of physical network can be transformed into an auto parts distribution system of e-commerce will be the lowest cost?Five, Auto parts network management is the only way for the development and reform of the road networkThe Chinese auto parts sales development should be appropriate for the situation in China, with Chinese characteristics, the way the Internet business. Indeed, the United States, network operators have achieved great success, but we can not ignore this brilliant behind the social basis of the United States strong material foundation. As early as 100 years ago, the U.S. has established a comprehensive road, rail, postal services, courier delivery system combining; today's society, Americans have been accustomed to "free currency trading." It can be said that today's Internet economy development in the United States should be a very natural result and is more than 200 years the United States as a free market economy based on natural product. Like a child to climb from the start with their bare hands, and then learn to walk, over time learned to run naturally. As the development of China, only two aspects of payment and delivery has become a fatal problem "bottleneck." How to combine the development of China's national conditions and characteristics of the Internet, be able to realistically do something practical auto parts network operators today is the development of priority. China'sauto parts e-commerce and enterprise network operators must follow the joint and it should be a very natural result is more than 200 years the United States as a free market economy based on natural product. Like a child to climb from the start with their bare hands, and then learn to walk, over time learned to run naturally. As the development of China, only two aspects of payment and distribution has become a fatal problem "bottleneck."How to combine the development of China's national conditions and characteristics of the Internet, Being able to realistically do something practical auto parts network operators today is the development of priority.汽车营销一、汽车配件网络化经营的概念美国汽车配件经销商雷蒙德的汽车配件店位于美国亚特兰大市的一个郊外，这个小店与别的配件店并无二致，但其特色是网上交易，任何与汽车配件销售相关的服务均可在互联网上实现。