摘要
Abstract
近年来，随着人们生活水平的提高，对汽车乘坐舒适性的要求也越来越高。汽车行驶的平顺性和操纵的稳定性已经逐渐成为其在现代市场竞争中夺取优势的一项非常重要的性能指标。本文首先通过建立汽车悬架系统的七自由度整体模型图，运用结构动力学和振动知识推导出系统在正弦激励下的拉格朗日方程，并简化为振动微分方程形式，通过MATLAB编制优化程序，求出系统的复特征值和在特定参数下的响应变化图形。然后，简述现代汽车悬架系统的各种控制方法，模拟仿真出系统在不同的刚度和阻尼下输出响应的图形，通过比较分析，为半主动悬架系统的减振器的阻尼和弹性元件的刚度控制提供根据。最后，得出本文的结论。即，汽车悬架的动力响应和控制分析与刚度和阻尼的变化之间的紧密联系。
In recent years, with the improvement of people's living standard, it is higher and higher to take the requirement for comfortableness to the car. Whom car go getting smooth-going and stability that handle become their capture one important performance index very of advantage among modern market competition gradually already. This text, through setting up whole model picture of degree of freedom seven that the car hung a system at first, use structural dynamics and vibration knowledge to derive the system out to encourage Lagrangian equation under in the sine, simplify it for the vibration differential equation form, work out the procedure of optimizing through MATLAB, ask out systematic replying characteristic value and response under the particular parameter and changing the figure. Then sketch Hyundai Motor hang sets of various of system control method, simulation emulation produce system output the figure responded under different rigidity and damping, through comparative analysis,hang sets of damping and rigidity of components elastic of shock absorbers of system control offer to half voluntarily according to. Finally, draw the conclusion herein. I.e., the car power of hanging the shelf responds and controls the close connection between analysis and change of rigidity and damping.
关键词：汽车悬架；响应；控制分析
Keyword: The car hangs the shelf; Response; Control and analyze
In the 20th century, bridge construction technology evolved and was fueled by the
Industrial Revolution. At the turn of the century, steel bridges were riveted together, not
bolted; concrete bridges were cast in place, not precast; and large bridge members were
built from lacing bars and smaller sections, not rolled in one piece. Plastic had not yet been
invented. Construction techniques such as post-tensioning, slurry walls, soil freezing, and
reinforced earth walls had not yet been conceived. Surveying was performed mechanically
since infrared, optical technology was still 75 years away.
Bridge construction is changing as the new millennium begins. New construction
techniques and new materials are emerging. There are also new issues facing the bridge
building industry relative to the research needs associated with these new techniques and
materials.
LONG-SPAN BRIDGES
Suspension Bridges
While suspension bridge building was conducted at a modest pace throughout the 20th
century, an unprecedented number of spans of remarkable record lengths were built in the
Far East and Denmark. Both the Akashi Kaikyo Bridge in Japan and the Great Belt Bridge
in Denmark were completed in 1998. The Akashi Kaikyo Bridge is the largest suspension
bridge in the world, with a span of 1991 m, and the Great Belt Bridge is the second largest,
with a span of 1624 m.
While spans lengths have increased nearly fivefold during the course of this century,
they may have reached their physical limits with today’s materials. Research will be
necessary to develop the new, ultra-high-strength steel wire or carbon fiber wire required to
build the longer main suspension cables that will make it possible to increase span lengths to
beyond 2000 m.
As we enter the new millennium, rehabilitation and ongoing maintenance of the existing
suspension bridges must continue as well. Recent rehabilitation measures for the main
cables and suspension systems of these bridges have uncovered degradation through
corrosion and hydrogen embrittlement. Research is needed to determine the remaining
useful service life of suspension bridge cables and what measures can be taken to slow or
halt the degradation process.
Transportation in the New Millennium 2
Other components of long-span bridges, existing and new, are being revolutionized as
technology moves forward. Advances in deck technology are producing stronger, lighter
decks. Orthotropic and exodermic decks are becoming increasingly popular on long-span
structures as a means of reducing dead load. Bearings, joint systems, and seismic retrofitting
components are becoming increasingly efficient as more large-scale testing facilities are
built.
在20世纪,桥梁施工技术,是由进化而来的
工业革命。随着新世纪的到来,钢桥受到铆接在一起,而不是
螺栓、混凝土桥梁被扔在的地方,不是预制、大型桥梁成员
从系酒吧和小的部分,不卷在一块。塑料尚未
发明了。制作等施工工艺、浆墙、土壤冻结,
加筋土墙尚未怀了孕。测量进行机械
自从红外、光学技术仍然是75年。
大桥建设是新千年开始转变。新建筑
技术和新材料正在浮出水面。也有新的解决面临的桥
建筑行业的相关研究的需要,这些新技术
材料。
大跨度桥梁
悬挂的桥梁
虽然悬索桥建设进行了整个20速度不快
世纪,前所未有的跨越了卓越的长度是建在记录
远东和丹麦。双方在日本明石海峡大桥正式通车,伟大的带桥
在丹麦是在一九九八年完成。这个明石海峡大桥正式通车是世界上最大的悬架
在这个世界上,与桥梁的m,1991年是中国的第二大带桥,
用一段1624)。
虽然已经增加了近5倍长度的跨世纪的过程中,
他们已经达到了他们的物理极限与今天的材料。研究将
必须发展新的、ultra-high-strength钢丝、碳纤维丝要求
建立了悬索,将不再主要可能增加到跨度的长度
超出2000米。
当我们进入新千年、康复和持续的维护现有的
悬索桥必须继续。最近的戒毒措施为主要
电缆悬架系统与这些桥梁发现退化
氢脆腐蚀,。研究还剩下的
寿命悬索桥电缆和什么措施可以减缓或
停止退化的过程。
在新千年的运输
其他组件的大跨度桥梁,现有的和新的,正在发生了革命性的变化
技术的进步。提出了在甲板上技术生产强的,更轻的
甲板。正交各向异性和exodermic牌是大跨度越来越受欢迎
作为一种手段,降低结构自重荷载。轴承、联合系统和抗震能力
越来越多的有效成分是更大规模的测试设备
建造。
50分！！~~谢谢
参考资料：我的大脑
Motor
vehicle suspension on the vehicle suspension system is a very important system.
Not only does it affect the comfort of the car (ride), but also to other
properties such as the adoption, as well as the stability of the attachment
have a significant impact on performance, each of the suspension by the elastic
components (buffers), body-oriented (from Chuan And stabilizing role), as well
as shock absorbers (from the role of shock absorption). However, not all of the
suspension must have three components. As long as we can play to the role of
the three.
Vehiclemaintenance for the conservation network 1, flying the classification
1.
Non-independent suspension: on both sides of the wheel mounted on a
total-vehicle-bridge, the train-bridge to fly through the frame and connected.
This suspension structure is simple and reliable power-but by two rounds of
shock and vibration affecting each other. But also because of the quality of
flying non-serious suspension of the poor performance of the buffer, the vibration
of a moving car, the greater the impact. The suspension generally used for
trucks, buses and a number of other ordinary vehicles. (2) independent
suspension: each individual through a set of wheels mounted on the body or
suspension of vehicular bridge, the use of off-Axle, in the middle of a fixed
frame or body; such wheel on both sides of the suspension by the shock
Hubuyingxiang, but due to non-flying than by the quality; buffer with a strong
shock absorption capacity, ride comfort. The indicators are better than
non-independent suspension, but the complex structure of the suspension, but it
also drive axle, steering system has become complicated. The use of such
suspension of the following two categories of vehicles. Cars, buses and
passenger vehicles. Can be improved ride comfort, and high speed when driving
the car to improve stability.
Off-road vehicles, military vehicles and
mining vehicles. In a bad way and have no say under the circumstances, we can
make sure all the wheels on the ground and contacts to enhance stability and
driving the car attached, to play a speed of the car.
2.Flexible
yuan for the type of (1) of the leaf spring: the long-range multi-chip and
curvature ranging from the composite plate. After installed at both ends of the
natural upward curve. In addition to the leaf spring with a buffer, there is a
certain degree of shock absorption, vertical layout also has a force-oriented,
non-independent suspension using most of the leaf spring so flexible
components, save-oriented devices and shock absorbers, simple structure . (2)
of the coil spring: only a cushion for the multi-car independent suspension. In
the absence of damping force and mass functions must also be equipped with
special shock absorbers and device-oriented. (3) oil and gas spring: a flexible
medium as a gas, liquid as a medium-power, which not only has a good buffer
capacity, also has a role in shock absorption and at the same time frame of a
high degree of regulation may also be applicable to the use of heavy vehicles and
buses. (4), torsion bar springs; will be made under the torsion bar springs
fixed at one end of the frame, on the other side through the arm and connected
to the wheels, and beat at wheel torsion bar the use of reverse deformation
played the role of buffer, is suitable for independent The use of suspension.
3.
the use of shock absorber tube shock absorbers, the use of oil in the small
role to cut energy consumption vibration. Shock absorber and the upper body
frame or connected with the lower end of the train-bridge connected. Most of
the trip can be done and the compression of the dual role of the role of shock
absorber.
4.device-oriented:
the flexibility in the independent suspension components, most of them can only
transfer the vertical loads and can not transmit vertical and horizontal, must
be a separate device-oriented. As noted, under the arm and vertical, horizontal
stabilizer, and so on.
5.
non-independent suspension: before and after the truckswere non-independent
suspension bridge, some vehicles such as buses and cars and so on, after the
bridge is also a non-independent suspension. Each car of the sedan chair by
hoisting two independent non-vertical arrangement of the composition of the
leaf spring. Leaf spring fixed in the middle of the train-bridge, with the
front end hinged frame or body, the back-end with the frame or body through the
ear hanging hinged or connected to use of skateboards. Top of the frame with a
shock absorber then, with the lower end of the next school Axle. The truck rear
axle and more without shock absorbers.
6.
many types of independent suspension, coil spring as the use of flexible
components. Torsion bar springs for the independent suspension is also divided
into vertical and horizontal torsion torque Cup two-under. Although many of the
advantages of an independent suspension, but the car would turn the system, the
Department of driving and driving more complicated structure of the bridge.
Keywords:
structure of the engine engine performance merits of a direct impact on the
performance of motor vehicles.
First, the use of fuel by the different
categories according to engine fuel, gasoline engine and the engine is divided
into two major categories of diesel engines.
1
.network Motor conservation maintenance, gasoline engine small size, light
weight, low prices; good start, when the maximum power of high-speed;work in a
small vibration and noise; suitable for small and medium-sized car in
particular, the use of high-speed car.Gasoline deflagration due to the restrictions
can not be too high compression ratio, thermal efficiency and economy are not,
such as diesel. Gasoline is a mixture of the main gas pipeline in the form over
into the cylinder, compressed by the end of close to the spark plugs fire. The
driver to speed up the adoption of the control pedal into the cylinder of the
gas mixture to control the load on the engine, known as the volume of
regulation. Gasoline engine’s fuel supply system and ignition system is a gasoline engine
failure on the part of a higher proportion. Gasoline engine emissions of
harmful material composition of carbon monoxide, carbon compounds and nitrogen
oxides than diesel, and so on, but with the current electronically controlled
fuel injection system and other exhaust gas purification devices, which have
greatly improved. In addition, the gasoline engine’s
torque characteristics are very suitable for automotive use, can significantly
reduce the labor intensity of the driver.
2.
diesel and gasoline engine, diesel engine size, weight, high prices, poor start
(especially when the low temperature); work more vibration and noise; easy to
overload when the black smoke. Diesel is characterized by:
1)
the absence of the deflagration, as well as restrictions on the needs of the
spontaneous combustion of diesel, diesel engine compression ratio high. Thermal
efficiency and economy must be better than the gasoline engine.
2)
the same power, the diesel engine’s torque, maximum power at the time of low speed, suitable for the
use of the truck.
3)
is a mixture of diesel engine cylinder internal form, no inlet throttle, the
intake of small resistance. The driver to speed up the adoption of fuel
injection control board, to change the engine load, known as the regulation of
quality, as there is no problem of hypoxia, emissions of hydrocarbons and
carbon monoxide content of less than gasoline.
4)
In the absence of the ignition system, as well as fuel supply device failure
rate low. Therefore, failure to less than diesel gasoline engine.
5)
diesel engine torque characteristics are not suitable for car driving cycle
needs, moving the stalls to use frequently, an increase of pilot labor
intensity. The main diesel engine for use in medium and heavy vehicles.
Second, the number of engine cylinder and
arrangement of the engine cylinder displacement equal to the volume of work
and.
Increase
in the number of cylinder engine will not only increase capacity, improve the
engine output power, but also to enable the smooth operation of the engine to
reduce noise and vibration. Hyundai Motor have adopted multi-cylinder engine.
Mini-car for more than 3-cylinder engine, small trucks, passenger cars and
medium-sized following for more than 4-cylinder engine; medium-sized trucks,
large cars and buses for more than 6-cylinder engine; Heavy-Duty Truck General
of 6-8 cylinder. 6-cylinder engine under a single row multi-cylinder in-line
mode; 8-cylinder V-type engines for alignment; some of the cars in order to
reduce engine height, length shortened, using V6, V8-type arrangement. Mini-car
use of 3-cylinder engine, most oblique way. In-line engine structure is simple
and cheap. The disadvantage is that a high degree of the engine higher longer
length.Is more a way. V-type engines with low height, short length, but the
structure of the complex, more expensive price, suitable for large-scale
engine. Water-cooled engine block using the whole cast. Small engines used
aluminum alloy materials, large-scale multi-engine for the cast iron. Cylinder
head bolts used in a fixed block on the plane, in addition to constitute a
closed cylinder combustion room, into the exhaust, valves are installed, and
spark plug valve, and so on.
Third,
the gasoline engine’s
fuel supply 1, the fuel-supply system carburetor gasoline engine fuel supply
line into carburetor and fuel-injection two major categories of carburetor main
oil installations operating principle is:
the work of the engine when the outside air In
the cylinder under the suction air filter to filter through into the cylinder.
When the air flow through the pipe section due to the smaller increase in the
velocity and pressure led to the decline in a certain vacuum. Float on the
interior of gasoline in the vacuum from the role of the main inlet into the
spray nozzle, the gas emitted by high-speed air currents disperse into mist,
known as fogging. And then to oil and oil-film evaporation space in the form of
evaporation, and the airway had mixed into the air mixture into the cylinder.
In order to achieve the economy, the main oil loading also uses the air brake.
The main nozzle at the indoor air, and along with a few scheduled to open
around the through-hole and air the same room. When the throttle opening
gradually increases, the air hole gradually connected with the air. Not only
reduces the vacuum so that the mixture-thinning, the main air nozzle is also
beneficial to the atomization of gasoline. 2. electronically controlled fuel
injection fuel-supply system carburetor fuel-supply device structure is simple,
reliable, cheap, easy maintenance. But the biggest drawback is that it can not
be precisely controlled mixture of concentration, resulting in incomplete
combustion, emissions of harmful ingredients, do not meet the stringent
requirements of environmental protection today. In addition, due to the
existence of the pipe so that the air resistance increases. There is also the
cylinder uneven distribution of gasoline and easy to produce and Qizu ice and
so on. In order to solve these problems, 80 electronically controlled fuel
injection system in the car engine on a wide range of applications more and
more.
electronically
controlled fuel injection system advantages: electronically controlled fuel
injection system (referred to as English EFI) has the following advantages:
1.
no matter under what conditions and in what conditions the engine can
accurately control the mixture of concentration, To make gasoline burn
completely full. This greatly reduces the emission of harmful components of
content, also has an excellent combustion engine of the economy.
2.
can supply, ignition temperature, such as centralized control, so that the work
of the engine performance, increased engine power output, lower fuel
consumption.
3.
the engine can always operate in a stable condition in a variety of conditions
so that all car drivers in accordance with the requirements of normal traffic.
4. In the absence of pipes, a small air
resistance. At the same time, difficult to produce Qizu, to the distribution of
gas cylinder uniform, and so on. The shortcomings of the fuel injection system
is the high cost structure of the complex and difficult to repair, and so on.
electronicallycontrolled fuel injection system of classification:
1) by way of testing the air quality into theway traffic density and speed of the way the two categories.
2) by way of fuel injection, the following two
categories. According to the location of the jet, into intake manifold junction
(SPI) and the jet intake manifold Department (MPI) are two jet, respectively,
also known as single-point and multi-point injection jet.
MPI is
currently widely used in the way.MPI is currently widely used in the
way. Department of gasoline ignition gasoline engine ignition system are
generally three categories: contact-type ignition system, electronic ignition
system, computer-controlled ignition system.
车辆悬架系统中的机动车辆悬架系统是一种非常重要的系统。它不仅对乘坐汽车的舒适度有影响，而且对附件的稳定性等其他性能有着显著的影响。每个悬挂的弹性元件(弹簧),是车架(起稳定作用)， 以及减振器的角色(减震)组成然而,并非所有的悬架必须有三个组成部分。只要我们能发挥三个作用。汽车的维护，悬架分类：
一 非独立悬架：两侧车轮安装在一根整体式车桥上，车轮连同车桥一起通过框架与车身相连。但这种悬架结构简单，可靠，制造方便，而是由两个轮冲击和振动轮互相影响。在载重汽车上被广泛应用。 但减震器的表现不佳，汽车行进中的震动越大，影响越严重，所以这种悬挂通常被用在卡车、客车和其他的普通车辆。
独立悬架:每个元件通过两侧车轮安装或悬挂在车架上，并且采用断开式车桥。安装了这种减震系统的车轮不易失重飞起，具有强大减震能力的缓冲器更是提供了舒适的乘驾感受。若一侧车轮相对于车架(或车身)的位置发生变化时，另一侧车轮不受影响。这种悬架结构复杂，且车身的平稳性和高速行驶的稳定性较好，因此在轿车和小客车上得到普遍采用。以上指标均优于非独立悬架，但是悬架的结构越复杂，驱动桥和转向系统也就越复杂。使用这种悬架的交通工有以下两种：
1汽车和客车等客运车辆：可以提高乘驾舒适度，并且当高速驾驶时能提高稳定性。
mining vehicles.越野车，军用车和采矿车。在路况不佳时，可以确保所有的车轮接触地面并提高稳定性，避免汽车起伏，发挥出汽车的速度。
二.弹性元件类型：1 钢板弹簧：它是由若干片长方形的钢板组合成的复合板，呈弯曲形。安装在自然向上的曲线两端。此外,钢板弹簧通过减震器起到某种程度的减震、传递垂直载荷的作用。在非独立悬架和导向机构中，也使用钢板弹簧这种弹性元件和减震器这样简单的结构。
2螺旋弹簧；只为多汽车独立悬架缓冲，在缺少阻尼力和质量职能的情况下，还必须具备特殊的减震器和导向装置。
3油气弹簧: 使用油液和高压气体作为弹性材料，不仅有很好的减震能力，可以吸收冲击。在同样情况下能够提供更好的调节作用，适用于重型车辆和客车。
4扭杆弹簧：汽车车架与车轮用扭杆弹簧，其一端固定在车架上而另一端与车轮连接，车轮上下跳动时扭杆产生扭转变形，靠扭转弹力来吸收振动能量适合独立悬架系统。
三.减震器减震筒的使用，油的使用可以切断震动造成的能里损耗。减震器上端与车底架相连，下端与车桥相连。减震器在大部分的行程可以起到压缩的双重作用
四.导向机构：独立悬架的弹性元件，大多数只能传递垂直载荷，并不能传递水平载荷，必须是分离的导向机构。如上所述，在力臂和垂直和水平稳定器等。
五.非独立悬架：非独立悬架位于卡车的前部和后部，像客车，汽车等一些车辆的后桥也是非独立悬架。每个轿车均由两个独立的非垂直的钢板弹簧构成。钢板弹簧固定在车桥中间,其前后端车架或车身通过耳朵悬铰链或使用滑板连接的。上面的框架用减振器的下端连接轴。车后桥一般无减震器。
六 .螺旋弹簧作为弹性元件被用在多种类型的独立悬架。 扭杆弹簧
torque Cup two-under.为独立悬架分成纵向和横向扭力矩杯两杆。 虽然独立悬架具有许多优点，但汽车将会通过更复杂的桥结构改进系统，驱动和驾驶。
关键词：发动机的结构发动机的性能对机动车辆的性能有着直接的影响。
首先，燃料使用不同类别根据发动机的燃料，分为汽油发动机和柴油发动机。
1网络汽车养护维修，汽油发动机体积小，重量轻，价格低；当最大速度运行是，启动好；运行时震动小，噪音小，适合小型和中型汽车，尤其是高速车。由于爆燃的限制，汽油机不可以有过高的压缩比，热效率，而且不如柴油经济。汽油是一种进入气缸中的主要气体管道的混合物，在压缩到接近底部的火花塞时点火。驾驶者加速踩油门时混合气体进入气缸来控制发动机的负载，这是常规。汽油发动机的燃料供给系统和点火系统是发生汽油发动机故障的比例较高的一部分。虽然汽油发动机比柴油排放更多的一氧化碳，碳化合物和氮氧化物等有害物质成分，但是,现在的电控燃油喷射系统和其他废气净化装置却有了很大的改善。但与目前的电控燃油喷射系统和其他尾气净化装置，极大地改善。此外，汽油发动机的扭矩特性非常适用于汽车，可以大大降低司机的劳动强度。
2柴油发动机和汽油发动机，柴油发动机的大小，重量，价格高，启动差（尤其是低温时），运行时震动和噪音大; 有黑烟，容易超负荷。柴油发动机机的特点是：
1）没有爆燃的限制，但柴油需要自燃，所以柴油发动机压缩比很高。 .热效率和经济性比汽油发动机更好。
2）柴油发动机适用于卡车，因为同样的功率，扭矩大，最大功率也大。
3）柴油发动机汽缸内的内部是的混合物，没有进油门，小阻力的进气管。 司机.司机加快采用燃油喷射控制板，通过改变发动机负荷，作为规管的质量，因为不存在缺氧问题，碳氢化合物和一氧化碳的排放量低于汽油。
4）由于没有点火系统，燃料供应设备故障率低。 因此，不低于汽油发动机。
5）柴油发动机扭矩特性并不适用于汽车驾驶循环的需求，移动的摊位，经常使用，是适合飞行员劳动强度的增加。主要适用于中型和重型车辆。
第二，发动机缸体及发动机缸体位移量相等的工作。
因此，增加汽缸发动机的数量，不仅能增加容量，提高发动机输出功率，而且能够使发动机顺利运作，以减少噪音和振动。现代汽车公司已采用多缸发动机。微型车超过3缸发动机，小卡车，客车和中型以下超过4缸发动机;中型卡车，大型轿车和客车超过6缸发动机;重型卡车一般6-8缸。6缸下单列多缸模式下，8缸V型直列发动机，有些的汽车，为减少发动机的高度，将长度缩短，安装使用V6发动机，V8发动机类型。微型汽车使用3缸发动机，大多是倾斜的。 .在直列发动机结构简单，便宜。 .缺点是，发动机的高度更高，长度更长。更是一个方式。
.V型发动机高度低，长度短，但其结构复杂，价格更昂贵，适用于大型发动机。
.水冷式发动机缸体采用整体铸造。小型发动机采用铝合金材料，而大型发动机多采用铸铁材料。
and so on.气缸盖螺栓是用在飞机上的固定块，除了构成一个封闭的汽缸燃烧室，进入排气管，阀门和火花塞等。
第三，汽油发动机的燃料供应1，燃料供应系统汽化器
汽油发动机燃料进入汽化器和燃油喷射器两种主要设备工作原理：
发动机工作时，外界空气被吸入空气过滤器，通过过滤器进入气缸。当空气流过管道部分由于较小的增长速度及压力的减少导致了真空。
Car parts
Engine
The engine is a power plant, which provides power to drive the automobile．
In most automobile engines，the explosive power of the mixture of air and gasoline drives the pistons．The pistons turn a crankshaft to which they are attached The rotating force of the crankshaft makes the automobile’s wheels turn．
Some automobiles are powered by another kind of engine，known as the rotary valve，rotating combustion engine or Wankel engine The rotary valve engine also draws in a mixture of air and fuel, which is then compressed and burnt．A motor revolving in an elliptical chamber is connected to a shaft，Which finally drives the rear wheels．In most automobiles．the engine is mounted at the front end of the car，with the clutch and gearbox immediately behind it；the engine, clutch and gearbox are assembled into a single unit
Suspension System
The function of the suspension system is to absorb vibrations due to the up and down motion of wheels．caused by the irregularities in the road surface . The springs, connecting linkages．and shock absorber comprise the suspension system of a vehicle．The suspension system is of two types:
(1)Rigid system
(2)Independent system
In the rigid system, the road springs are attached to a rigid beam axle. It is mostly used in the front axle of commercial vehicles and in the car axle of all types of vehicles.
The independent system does not have a rigid axle. Each wheel is free to move vertically without any reaction on its mating wheel. The independent system is mostly used in small cars
Power Train
The power train carries the power that the engine produces to the car wheels. It consists of the clutch (on cars with a manual transmission), transmission (a system of gears that increases the turning effort of the engine to move the automobile ),drive shaft, differential and rear axle.
Clutch
A clutch is required with the manual transmission system to temporarily disconnect the engine from wheels. Such disengagement of the power train from the engine is essential while changing the gear ratio or while stopping the vehicle.
Transmission
The main function of the transmission is to provide the necessary variation to the torque applied by the engine to the wheels. This is achieved by changing the gearing ratio between the engine output shaft and the drive shaft.
Drive Shaft
The drive shaft or propeller connects the gearbox and the differential unit. The drive shaft has universal joints at its ends．
Differential
The function of the differential is to split the power received from the propeller shaft to the rear axle shaft. It allows the rear wheels to be driven at different speeds when the vehicle takes a bend or falls into a ditch.
Axles
Axles are the shafts on which road wheels are mounted. The road wheels are provided with the required drive through these axles．
Wheel
The automobile wheels take the load of the vehicle and also produce tractive force to move the vehicle. The wheels are also used for retardation and for stopping the vehicle.
Steering System
The steering system is used for changing the direction of the vehicle .The major requirements in any steering mechanism are that it should be precise and easy to handle, and that the front wheels should have a tendency to return to the straight-ahead position after a turn. A gear mechanism, which is known as steering gear, is used in this system to increase the steering effort provided by the driver. This system makes the vehicle steering very easy as the driver does not have to put in much effort．Vehicle steering is not only required on a curved road but also while maneuvering on the busy traffic roads．The steering system allows the vehicle to be guided i．e．to be turned left or right.
Braking System
Brakes are required for slowing down or stopping a moving vehicle．The braking system may be operated mechanically or hydraulically. 95 percent of the braking systems in use today are of the hydraulic type.
All brake consist of two members．one rotating and the other stationary．There are various means by which the two member call be brought in contact，thus reducing the speed of the vehicle.
The major components of the braking system are：brake pedal, master cylinder, wheel Cylinder, brake pipe，brake shoes．brake packing plant and linkages．As the load on the vehicle and the vehicle speed has increased according to recent trends．in modem days, the importance of the braking system has also increased and power brakes are now being preferred．Power brakes utilize vacuum and air pressure to provide most of the brake————applying effort.
汽车部件
发动机
发动机是一种动力机械设备．它为汽车提供动力。
在大部分汽车发动机中．空气和汽油的混合气体产生的爆炸性能量驱动活动活塞运动。活塞使它们所连接的曲轴转动。曲轴的转动力量使汽车的车轮转动。
一些汽车是由另外一种发动机提供动力的，这种发动机被认为是旋转气门、旋转燃烧或汪克尔发动机。转子发动机也是吸入空气和燃料的混合气，混合气被压缩和燃烧•在一个椭圆形的室内旋转的发动机连接着一个轴，这个轴将最终驱动后面的车轮。大部分汽车中，发动机是架在汽车的前面末端的，离台器和变速箱在它后面，发动帆、离台器和变速箱被装配成一个整体。
发动机工作时有很多系统都是必要的。润滑系统可以减少摩擦并减轻发动机磨损。冷却系统被用来保持发动机的温度在安全范围内。发动机必须有燃油系统保证适当数量的空气和燃料供给。
空气和燃油混合物必须由点火系统在适当的时间在气缸内被点燃。最后，电子系统被用来控制启动发动机用的电动机和为发动机附件提供电能。
润滑系统
发动机有许多最终会被磨损的运动部件，因为它们是相对运动的。发动机使润滑油在这些运动的部件间循环，以避免因金属与金属之间的接触而导致磨损。被润滑过的部件能够因为摩擦减少而容易运动，因摩擦导致的能量损失是最小的。润滑油的第二个功能是作为冷却液和防止泄露。最后，气缸壁上的润滑油薄膜有助于活塞环密封并因此提高发动机的压缩性。
冷却系统
由于燃料与空气在气缸内燃烧，从而使发动机部件温度升高。温度升高直接影响发动机的性能和发动机部件的寿命。冷却系统使发动机工作保持在有效的温度。不管驾驶条件如何，发动机系统被设计成既能防止过热又能防止过冷。
燃料供给系统
燃料供给系统的主要功能是以一定的比例和压力给化油器或喷射系统提供燃料，并在汽车遇到的所有情况下，满足发动机对负载、速度和坡度的需要。燃料系统也必须为汽车行驶几英里保留足够的燃料。
身提供了一个安装框架。车架用方刚或盒形钢铁制造，有足够的强度支撑车身和其他构件的重量。汽车车架通常由一些焊接或铆接在一起的零件构成，从而形成最后的形状。发动机和橡胶垫被圈定在车架上。橡胶垫可以吸收振动，也可以提供这些振动的阻尼减轻乘客由于振动产生的不适。
悬架系统
悬架系统的功能是吸收由于路面不平使车轮上下运动所产生的振动。弹性元件、连接装置和减振器组成了汽车的悬架系统。悬架系统有两种类型：
(1)刚性悬架系统
(2)独立悬架系统
在刚性悬架系统中，弹簧被系在刚性横梁上，这种系统主要被用在商用车辆的前轴和所有类型车辆的车轴上。
独立悬架系统没有一根坚硬的轴。每个车架可以自由做垂直运动而相对应的另一侧车轮没有任何反应。独立悬架系统主要用在小汽车上。
传动系统
传动系把发动机产生的能量传递给车轮。它包括离台器(汽车上用手动变速器)、传动系(一系列的齿轮，把由发动机产生的转矩增强．推动汽车)、驱动轴、差速器和后挢。
离合器
离合器用于手动变速的传动系统。用它暂时把发动机和车轮之间的动力传递分开。当换档或停车时，把传动系和发动机的连接断开是很必要的。
变速籍
变速箱的主要功能是通过发动机把各种必需的扭矩提供给车轮，这是通过改变发动机输出轴和驱动轴两者之阃的传动比来实现的。
驱动轴
驱动轴或叫推动轴与齿轮箱和差动器相连。驱动轴通常在末端具有万向节。
差速器
差速器的功能是把来自传动轴的能量分给后轿。当汽车转弯或掉沟时，它允许后轮以不同的逮度驱动。
车轿
车桥是指用来安装车轮的轴，通过这些车桥向车轮提供必需的驱动力。
车轮
车轮支承着整辆车．并产生牵引力来驱动汽车。车轮也用于减速和停车。
转向系统
转向系统是用来改变汽车方向的，在任何转向机构中最主要的就是转向精确且容易控制，同时前轮在转向后又能自动回正。一个齿轮机构，通常认为是转向齿轮，在这个系统内用来增强由驾驶员提供的转向力，这个系统使得汽车转向非常容易，驾驶员不用费报大的力。不仅仅是在弯曲的公路上需要汽车转向，在交通拥挤的路上也需要巧妙地控制。转向系统使得汽车可以被控制向左或者向右转向。
制动系统
制动用来使车辆放慢速度或者停车。制动系统可以是机械制动或者液压制动。现在用的制动系统95％都是液压型的。
所有的制动系统都包含两种元件，一种是旋转零件，另一种是固定零件，有各种各样方法使得这两个元件相接触而使车辆减速。制动系统的主要组成部分：制动踏扳、主制动缸、车轮制动、制动鼓、制动管路、制动蹄、制动装备和联动装置。随着汽车负载和车速的增大，目前制动系统的重要性也在增大，并且现在人们更喜欢助力制动。助力制动利用真空和空气压力来提供更好的制动力。
