0016-四座微型客货两用车-变速器、传动轴和操纵机构设计（CAD图+翻译）
收藏
资源目录
压缩包内文档预览：(预览前20页/共42页)
编号：49274013
类型：共享资源
大小：1.65MB
格式：RAR
上传时间：2020-02-13
上传人：qq77****057
认证信息
个人认证
李**（实名认证）
江苏
IP属地：江苏
29
积分
- 关 键 词：
-
0016
四座
微型
客货两用车
变速器
传动轴
操纵
机构
设计
CAD
翻译
- 资源描述：
-
0016-四座微型客货两用车-变速器、传动轴和操纵机构设计（CAD图+翻译）,0016,四座,微型,客货两用车,变速器,传动轴,操纵,机构,设计,CAD,翻译
- 内容简介：
-
外文翻译原文INTERNAL COMBUSTION ENGINE1.Engine Block and Cylinder HeadThe 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.The engine block also holds the crankshaft, which fastens to the bottom of the block. The camshaft also fits inside the block, except on overhead-cam engines (OHC). 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. Some 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.The 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. The most common cylinder head types are the hemi, wedge, and semi-hemi.All three of these terms refer to the shape of the engines combustion chamber. The cylinder head carries the valves, valve springs and the rockers on the rocker shaft, this part of the valve gear being worked by the push-rods. Sometimes the camshaft is fitted directly into the cylinder head and operates on the valves without rockers. This is called an overhead camshaft arrangement. Like the cylinder block, the head is made from either cast iron or aluminum alloy.2.Gasket The 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. This is a sandwich gasket, i.e. a sheet of asbestos between two sheets of copper, both these materials being able to withstand the high temperature and pressures within the engine.3.Oil Pan or SumpThe oil pan is usually formed of pressed steel. The oil pan and the lower part of the 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 runs down into the pan. Thus, there is constant circulation of oil between the pan and the working parts of the engine.4.Cooling SystemThe purpose of the cooling system is to keep the engine at its most efficient operating temperature at all speeds under all driving conditions.As fule is burned in the engine, about one-third of the heat energy in the fuel is converted into power.Another third goes out through the exhaust pipe unused, and the remaining third must be handled by the cooling system.This means that the engine can work effectively only when the heat energy is equally handled so as to keep the engine temperature in balance.So,the temperature is quite essential for an engine to produce power.No engines can work well without suitable operating temperatures.If the engine runs too hot, it may suffer from pre-ignition,while the air-fule charge is ignited prematurely from escessive combustion chamber temperature.Viscosity of the oil circulating in an over heating engine is reduced.Hot oil alvarnish and carbon depostis may be drawn into the combustion chamber where it increases HC emission.This also causes poor performance and premature wear, and may even result in engine damage.Whats more, the begavior of the metals at excessively high temperature also differs from that at normal temperatures and can produce a condition in which the metal deforms slowly and continuously at a constant stress.If the engine runs too cold, the fuel will not vaporize properly. If liquid fuel reaches the cylinders, it will reduce lubrication by washing the oil from the cylinder walls and diluting the engine oil.This causes a loss of performance, an increase in HC emissions, and premature engine wear. For these reasons, a ooling system of some kind is necessary in any internal combustion ebgine.5.Valve SystemIf the inlet valve opened at TDC of the intake stroke and closed at BDC of that stroke, it would have a duration of 180.It would have remained open for half of a complete 360 revolution, or 180. However, it takes some time for the valve to open to its full position. It also takes time for it to close tightly. Therefore the valve is opened before TDC (BTDC) and closed after BDC (ABDC). If the exhaust valve opened at BDC at the beginning of the exhaust stroke and closed at TDC at the end of the exhaust stroke, it would have a duration of 180. But like the inlet valve, the exhaust valve needs time to reach the full-open position, It also needs time to reach the full-closed position. So the exhaust valve opens before BDC and closes after TDC. The intake opens at 17 BTDC and the exhaust closes at 17 ATDC. Thus, for a period of 34, both of the valves are open: (17 + 17 =34). This period of time is known as valve overlap. The closing of the exhaust valve laps over the opening of the intake valve. During this time, the first of the new mixture pushes the last of the burned gases out the exhaust valve. Valve overlap is held to a minimum on turbo-charged engines. This prevents the intake charge from being blown out the exhaust. To coordinate the four-stroke cycle, a group of parts called the valve train opens and closes the valves (moves them down and up, respectively). These valve movements must take place at exactly the right moments. The opening of each valve is controlled by a camshaft.The cam is an egg-shaped piece of metal on a shaft that rotates in coordination with the crankshaft. The metal shaft, called the camshaft, typically has individual cams for each valve in the engine. As the camshaft rotates, the lobe, or high spot of the cam, pushes against parts connected to the stem of the valve. This action forces the valve to move downward. This action could open an inlet valve for an intake stroke, or open an exhaust valve for an exhaust stroke.As the camshaft continues to rotate, the high spot moves way from the valve mechanism. As this occurs, valve springs pull the valve tightly closed against its opening, called the valve seat. Valves in modern car engines are located in the cylinder head at the top of the engine. This is known as an overhead valve (OHV) configuration. In addition, when the camshaft is located over the cylinder head, the arrangement is known as an overhead camshaft (OHC) design. Some high-performance engines have two separate camshafts, one for each set of inlet and exhaust valves. These engines are known as dual overhead camshaft (DOHC) engines.The camshaft also can be located in the lower part of the engine, within the engine block. To transfer the motion of the cam upward to the valve, additional parts are needed. In this arrangement, the cam lobes push against round metal cylinders called cam follower. As the lobe of the cam comes up under the cam follower, it pushes the cam follower upward (away from the camshaft). The cam follower rides against a push rod, which pushes against a rocker arm. The rocker arm pivots on a shaft through its center. As one side of the rocker arm moves up, the other side moves down, just like a seesaw. The downward-moving side of the rocker arm pushes on the valve stem to open the valve. Because a push-rod valve train has additional parts, it is more difficult to run at high speeds. Push-rod engines typically run at slower speeds and, consequently, produce less horsepower than overhead-camshaft designs of equal size. (Remember, power is the rate at which work is done.) When the engine runs in compression stroke and power stroke, the valves must close tightly on their seats to produce a gas-tight seal and thus prevent the gases escaping from the combustion chamber. If the valves do not close fully the engine will not develop full power. Also the valve heads will be liable to be burnt by the passing hot gases, and there is the likelihood of the piston crown touching an open valve, which can seriously damage the engine. So that the valves can close fully some clearance is needed in the operating mechanism. This means that the operating mechanism must be able to move sufficiently far enough away from the valve to allow the valves to be fully closed against its seat by the valve spring. However, if the clearance is set too great this will cause a light metallic tapping noise. Each cam must revolve once during the four-stroke cycle to open a valve. A cycle, remember, corresponds with two revolutions of the crankshaft. Therefore, the camshaft must revolve at exactly half the speed of the crankshaft. This is accomplished with a 2:1 great ratio. A gear connected to the camshaft has twice the number of teeth as a gear connected to the crankshaft. The gears are linked in one of three ways:（1）Belt drive A cog-type belt can be used. Such belts are made of synthetic rubber and reinforced with internal steel or fiberglass strands. The belts have teeth, or slotted spaces to engage and drive teeth on gear wheels. A belt typically is used on engines with overhead-cam valve trains.（2）Chain drive On some engines, a metal chain is used to connect the crankshaft and camshaft gears. Most push-rod engines and some OHC engines have chains. l （3）Gear drive The camshaft and crankshaft gears can be connected directly, or meshed. This type of operating linkage commonly is used on older six-cylinder, inline engines. A camshaft driven by a chain or belt turns in the same direction as the crankshaft. But a camshaft driven directly by the crankshaft gear turns in the opposite direction. Timing belts are used because they cost less than chains and operate more quietly. A typical timing belt is made of neoprene (synthetic rubber) reinforced with fiberglass. 6.Piston The piston is an important part of a four-stroke cycle engine. Most pistons are made from cast aluminum. The piston , through the connecting rod, transfers to the crankshaft the force create by the burning fuel mixture. This force turns the crankshaft .Thin, circular , steel bands fit into grooves around the piston to seal the bottom of the combustion chamber. These bands are called piston rings. The grooves into which they fit are called ring grooves. A piston pin fits into a round hole in the piston . The piston pin joins the piston to the connecting rod . The thick part of the piston that holds the piston is the pin boss.The piston itself , its rings and the piston pin are together called the piston assembly. To withstand the heat of the combustion chamber, the piston must be strong. It also must be light, since it travels at high speeds as it moves up and down inside the cylinder. The piston is hollow. It is thick at the top where it take the brunt of the heat and the expansion force. It is thin at the bottom, where there is less heat. The top part of the piston is the head , or crown . The thin part is the skirt The sections between the ring grooves are called ring lands.The piston crown may be flat , concave ,dome or recessed . In diesel engine , the combustion chamber may be formed totally or in part in the piston crown , depending on the method of injection . So they use pistons with different shapes.7.Piston RingsAs Fig shows , piston rings fit into ring grooves near the of the piston. In simplest terms, piston rings are thin, circular pieces of metal that fit into grooves in the tops of the pistons. In modern engines ,each piston has three rings. (Piston in older engines sometimes had four rings, or even five.) The rings outside surface presses against the cylinder walls. Rings provide the needed seal between the piston and the cylinder walls. That is, only the rings contact the cylinder walls. The top two rings are to keep the gases in the cylinder and are called compression rings. The lower one prevents the oil splashed onto the cylinder bore from entering the combustion chamber , and is called an oil ring. Chrome-face cast-iron compression rings are commonly used in automobile engines. The chrome face provide a very smooth , wear-resistant surface.During the power stoke , combustion pressure on the combustion rings is very high. It causes them to untwist . Some of the high-pressure gas gets in back of the rings. This force the ring face into full contact with the cylinder wall. The combustion pressure also holds the bottom of the ring tightly against the bottom of the ring groove. Therefore , high combustion pressure causes a tighter seal between the ring face and the cylinder wall.8. Piston Pin The piston pin holds together the piston and the connecting rod . This pin fits into the piston pin holes and into a hole in the top end of the connecting rod. The top end of is much smaller than the end that fits on the crankshaft . This small end fits inside the bottom of the piston . The piston pin fits through one side of the piston , through the small end of the rod , and then through the other side of the piston . It holds the rod firmly in place in the center of the piston. Pins are made of high-strengh steel and have a hollow center . Many pins are chrome-plated to help them wear better.8外文翻译译文内燃机1.气缸体和气缸盖气缸体是发动机的基本框架。发动机的其他零件都安装在它里面或者固定在它上。缸体里有气缸，水套和油道。曲轴也固定在气缸体底部。除了顶置凸轮(OHC)发动机以外，凸轮轴都安装在气缸体里面。在大多数汽车里，气缸体由灰铸铁或者一种灰铸铁和其他金属的合金(混合物)做成，例如镍或铬。气缸体是铸件。 有些气缸体，特别是在小汽车里的那些，都是由铝做成的。这种金属比铸铁轻得多。但是，铸铁的耐磨性比铝好。因此，在大多数铝制发动机的气缸内镶有铸铁或者钢的轴套。这些轴套叫做气缸套。而有些气缸体完全由铝做成。气缸盖固定在气缸体的顶上，正像屋顶套在一所房子上面一样。气缸盖下面与活塞顶上的空间形成燃烧室。最常见的气缸盖类型是半球形，楔形和准半球形。这三种说法都是指燃烧室的形状。气缸盖携带阀门，气门弹簧和在摇臂杆上的摇臂，这部分的气门传动机构通过推杆工作。有时，凸轮轴直接安装在气缸盖上并且不用摇臂控制阀门工作。这被叫为顶置凸轮轴装置。像气缸体一样，气缸盖是由铸铁或者铝合金制成。2.衬垫气缸盖与气缸体用高强度的钢螺栓缚连结。气缸体和气缸盖之间的连接必须密封以便没有燃烧的混合气体泄漏。这通过使用气缸盖衬垫实现。这是一个夹层衬垫，即在两片铜之间放一片石棉，这两种材料都能禁得住在发动机内的高温和高压。3.油底壳油底壳通常由钢冲压形成。油底壳和气缸体的下半部分一同被叫做曲轴箱；他们把曲轴封闭起来。润滑系统中的机油泵从油底壳抽取油并把油输送到发动机内全部正在工作的部分。机油流出后又流回油底壳。因而在油底壳和发动机工作零件之间有机油不断流动循环。4.冷却系统冷却系统的作用是保证引擎在任何路况的任何车速下都在最高效的的运行温度中。随着燃油在引擎中燃烧，的热量转化成动力。还有随排气管排出而得不到有效利用，剩下的热量在冷却系统的作用下散失掉了。这意味着只有当热量得到适当的处理引擎温度处于平衡状态时引擎才能高效工作。所以，温度对引擎产生动力的意义是重大的。任何引擎在不好的运行温度下都工作不好。如果引擎过热，当压缩混合气由于燃烧室温度过高被过早点着，就会造成混合气早燃。润滑油润滑循环在过热的引擎中降低。灸热的润滑油气和碳积物可能沉积在燃烧室中导致炭氢化物排放上升。这同样会引起引擎性能欠佳和过早磨损，甚至导致引擎损坏。另外，在过高的温度下金属的反应也不同于正常温度，过高的温度会引起金属的缓慢变形和金属承受持续的恒定压力。如果引擎工作过冷，汽油蒸发就不好。如果气缸有液态汽油，液态汽油会冲走气壁的润滑油稀释引擎中的润滑油导致润滑油过少。这造成了引擎性能下降，排增加，和引擎过早磨损。由于这些原因，冷却系统是内燃机必不可少的。5.配气机构如果进口门在进气行程的上止点打开并且在这次行程的下止点关闭，它将有180的开度。气门在180转角内完全打开。然而气门达到全开位置需要一定时间，完全关闭也需要一定时间。因此阀门在上止点(BTDC)之前被打开，在下止点(ABDC)之后关闭。如果排气门在排气行程的下止点打开并且在这次行程的上止点关闭，它将有180的持续。但是像进气门一样，排气门需要时间到达充分打开和关闭的位置。因此排气门在下止点之前打开，在上止点之后关闭。进气门在上止点前17打开，排气门在上止点后17关闭。 因此，有34的一段时期，两个阀门都是开的：(17+ 17= 34)。这时期被称为气门重叠。排气门的关闭和进气门的开启重叠。在这个时候，新的混合气推动燃烧后的废气从排气门排出。在涡轮增压发动机上气门重叠角被保持在一个最小值。这就防止废气倒流入进气管。那些打开和关闭气门的气门传动是为了协调四冲程的工作循环(使他们各自上下移动)。这些阀门运动必须正好在合适的时刻进行。每个阀门的开启由凸轮轴控制。凸轮是一在轴上的蛋形的金属，通过曲轴协调旋转。那金属轴叫凸轮轴，在发动机里的每个气门一般有各自的凸轮。当凸轮轴旋转时，凸轮凸起的或者高点的位置，推动气门座。这行动强迫阀门向下移动。这过程能使进气门在进气行程打开，或者排气门在排气行程打开。因为凸轮轴继续旋转，凸轮轴上的凸起部分离开气门装置。当这发生时，气门弹簧紧紧地关闭气门口，叫做气门座。 现代汽车发动机里的阀门位于发动机顶上的汽缸盖。这被称为顶置气门(OHV)结构。另外，当凸轮轴位于汽缸盖上面时，这种方式被称为是顶置凸轮轴(OHC)结构。一些高性能发动机有两个单独的凸轮轴，分别负责开关进气门和排气门。这些发动机被称为双顶置凸轮轴(DOHC)发动机。凸轮轴也装在发动机底部的气缸体内。为了将凸轮的运动传给气门需要一些附属装置。 在这种布置中，凸轮凸角
- 温馨提示:
1: 本站所有资源如无特殊说明，都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
2: 本站的文档不包含任何第三方提供的附件图纸等，如果需要附件，请联系上传者。文件的所有权益归上传用户所有。
3.本站RAR压缩包中若带图纸，网页内容里面会有图纸预览，若没有图纸预览就没有图纸。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 人人文库网仅提供信息存储空间，仅对用户上传内容的表现方式做保护处理，对用户上传分享的文档内容本身不做任何修改或编辑，并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容，请与我们联系，我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。
人人文库网所有资源均是用户自行上传分享，仅供网友学习交流，未经上传用户书面授权，请勿作他用。
川公网安备: 51019002004831号