车辆工程外文翻译---制动系统

附录1

Brake Systems

1.Drum vs. Disc

Brake technology, just like suspension technology and fuel-system technology, has come a long way in recent years.

1）Drum Brakes

Early automotive brake systems, after the era of hand levers of course, used a drum design at all four wheels. They were called drum brakes because the components were housed in a round drum that rotated along with the wheel. Inside was a set of drum that, when the brake pedal was pressed, would force the shoes against the drum and slow the wheel. Fluid was used to transfer the movement of the brake pedal into the movement of the brake shoes, while the drum themselves were made of heat-resistant friction material similar to that used on clutch plates.

This basic design proved capable under most circumstances, but it had one major flaw. Under high braking conditions, like descending a steep hill with a heavy load or repeated high-speed slow downs, drum brakes would often fade and lose effectiveness. Usually this fading was the result of too much heat build-up within the shoes. Remember that the principle of braking involves turning kinetic energy (wheelmovement) into thermal energy (heat). For this reason, drum brakes can only operate as long as they can absorb the heat generated by slowing a vehicle's wheels. Once the brake components themselves become saturated with heat, they lose the ability to halt a vehicle, which can be somewhat disconcerting to the vehicle's operator.

2） Disc Brakes

Disc brakes are used on the front wheels of most cars and on all four wheels on

many cars. A disc rotor is attached to the wheel hub and rotates with the tire and wheel. When the driver applies the brakes, hydraulic pressure from the master cylinder is used to push friction linings against the rotor to stop it.

In the disc brake rotor assembly, the rotor is usually made of cast iron. The hub may be manufactured as one piece with the rotor or in two parts. The rotor has a machined braking surface on each face. A splash shield, mounted to the steering knuckle, protects the rotor from road splash.

A rotor may be solid or ventilated. Ventilated designs have cooling fins cast between the braking surfaces. This construction considerably increases the cooling area of the rotor casting. Also, when the wheel is in motion, the rotation of these fan-type fins in the rotor provides increased air circulation and more efficient cooling of the brake. Disc brakes do not fade even after rapid, hard brake applications because of the rapid cooling of the rotor.

The hydraulic and friction components are housed in a caliper assembly. The caliper assembly straddles the outside diameter of the hub and rotor assembly. When the brakes are applied, the pressure of the pistons is exerted through the shoes in a 'clamping＇action on the rotor. Because equal opposed hydraulic pressures are applied to both faces of the rotor throughout application, no distortion of the rotor occurs, regardless of the severity or duration of application. There are many variations of caliper designs, but they can all be grouped into two main categories: moving and stationary caliper. The caliper is fixed in one position on the stationary design. In the moving design, the caliper moves in relation to the rotor.

Most late-model cars use the moving caliper design. This design uses a single hydraulic piston and a caliper that can float or slide during application. Floating designs｀float＇or move on pins or bolts. In sliding designs, the caliper slides sideways on machined surfaces. Both designs work in basically the same way.

In the single piston floating caliper, the single-piston caliper assembly is constructed from a single casting that contains one large piston bore in the inboard section of the casting. Inboard refers to the side of the casting nearest the center line of the car when the caliper is mounted. A fluid inlet hole and bleeder valve hole are machined into the inboard section of the caliper and connect directly to the piston bore.

The caliper cylinder bore contains a piston and seal. The seal has a rectangular cross section. It is located in a groove that is machined in the cylinder bore. The seal

fits around the outside diameter of the piston and provides a hydraulic seal between the piston and the cylinder wall. The rectangular seal provides automatic adjustment of clearance between the rotor and shoe and linings following each application. When the brakes are applied, the caliper seal is deflected by the hydraulic pressure and it inside diameter rides with the piston within the limits of its retention in the cylinder groove. When hydraulic pressure is released, the seal relaxes and returns to its original rectangular shape, retracting the piston into the cylinder enough to provide proper running clearance.

As brake linings wear, piston travel tends to exceed the limit of deflection of the seal; the piston therefore slides in the seal to the precise extent necessary to compensate for lining wear.

The top of the piston bore is machined to accept a sealing dust boot. The piston in many calipers is steel, precision ground, and nickel chrome plated, giving it a very hard and durable surface. Some manufacturers are using a plastic piston. This is much lighter than steel and provides for a much lighter brake system. The plastic piston insulates well and prevents heat from transferring to the brake fluid. Each caliper contains two shoe and lining assemblies. They are constructed of a stamped metal shoe with the lining riveted or bonded to the shoe and are mounted in the caliper on either side of the rotor. One shoe and lining assembly is called the inboard lining because it fits nearest to the center line of the car. The other is called the outboard shoe and lining assembly.

The application and release of the brake pressure actually causes a very slight movement of the piston and caliper. Upon release of the braking effort, the piston and caliper merely relax into a released position. In the released position, the shoes do not retract very far from the rotor surfaces.

As the brake lining wears, the piston moves out of the caliper bore and the caliper repositions itself on the mounting bolts an equal distance toward the car. This way, the caliper assembly maintains the inboard and outboard shoe and lining in the same relationship with the rotor surface throughout the full length of the lining.

Sliding calipers are made to slide back and forth on the steering knuckle support to which it is mounted. There is a V shaped surface, sometimes called a rail, on the caliper that matches a similar surface on the steering knuckle support. These two mating surfaces allow the caliper to slide in and out. The internal components of the caliper are the same as those previously described.

The stationary or fixed caliper has a hydraulic piston on each side of the rotor. Larger calipers may have two pistons on each side of the rotor. The inboard and outboard brake shoes are pushed against the rotor by their own pistons. The caliper is anchored solidly and does not move. The seals around the pistons work just like those already described. The main disadvantage of the stationary caliper is that it has more hydraulic components. This means they are more expensive and have more parts to wear out .

2.Other Components in the Hydraulic System:

1）Proportioning Valve or Equalizer Valve

These valves are mounted between the master cylinder and the rear wheels. They are designed to adjust the pressure between the front and rear brakes depending on how hard you are st opping. The shorter you stop, the more of the vehicle’s weight is transferred to the front wheels, in some cases, causing the rear to lift and the front to dive. These valves are designed to direct more pressure to the front and less pressure to the rear the harder you stop. This minimizes the chance of premature lockup at the rear wheels.

2）Pressure Differential Valve

This valve is usually mounted just below the master cylinder and is responsible for turning the brake warning light on when it detects a malfunction. It measures the pressure from the two sections of the master cylinder and compares them. Since it is mounted ahead of the proportioning or equalizer valve, the two pressures it detects should be equal. If it detects a difference, it means that there is probably a brake fluid leak somewhere in the system.

3）Combination Valve

The Combination valve (Figure) is simply a proportioning valve and a pressure differential valve that is combined into one unit.

The parking brake (a．k．a．emergency brake ) system controls the rear brakes through a series of steel cables that are connected to either a hand lever or a foot pedal. The idea is that the system is fully mechanical and completely bypasses the hydraulic system so that the vehicle can be brought to a stop even if there is a total brake failure.

On drum brakes, the cable pulls on a lever mounted in the rear brake and is directly connected to the brake shoes. This has the effect of bypassing the wheel cylinder and controlling the brakes directly.

Disk brakes on the rear wheels add additional complication for parking brake

systems. There are two main designs for adding a mechanical parking brake to rear disk brakes. The first type uses the existing rear wheel caliper and adds a lever attached to a mechanical corkscrew device inside the caliper piston. When the parking brake cable pulls on the lever, this corkscrew device pushes the piston against the pads, thereby bypassing the hydraulic system, to stop the vehicle. This type of system is primarily used with single piston floating calipers, if the caliper is of the four piston fixed type, then that type of system can’t be used. The other system uses a complete mechanical drum brake unit mounted inside the rear rotor. The brake shoes on this system are connected to a lever that is pulled by the parking brake cable to activate the brakes. The brake “drum” is actually the inside part of the rear brake rotor.

On cars with automatic transmissions, the parking brake is rarely used. This can cause a couple of problems. The biggest problem is that the brake cables tend to get corroded and eventually seize up causing the parking brake to become inoperative. By using the parking brake from time to time, the cables stay clean and functional. Another problem comes from the fact that the self adjusting mechanism on certain brake systems uses the parking brake actuation to adjust the brakes. If the parking brake is never used, then the brakes never get adjusted.

The power brake booster (Figure) is mounted of the firewall directly behind the master cylinder and, along with the master cylinder, is directly connected with the brake pedal. Its purpose is to amplify the available foot pressure applied to the brake pedal so that the amount of foot pressure required to stop even the largest vehicle is minimal. Power for the booster comes from engine vacuum. The automobile engine produces vacuum as a by-product of normal operation and is freely available for use in powering accessories such as the power brake booster. Vacuum enters the booster through a check valve on the booster. The check valve is connected to the engine with a rubber hose and acts as a one-way valve that allows vacuum to enter the booster but dose not let it escape. The booster is an empty shell that is divided into two chambers by a rubber diaphragm. There is a valve in the diaphragm that remains open while foot is off the brake pedal so that vacuum is allowed to fill both chambers. When stepping on the brake pedal, the valve in the diaphragm closes, separating the two chambers and another valve opens to allow air in the chamber on the brake pedal side. This is what provides the power assist. Power boosters are very reliable and cause few problems of their own. However, other things cam contribute to a loss of power assist. In order to have power assist, the engine must be running. If the engine stalls or shuts

off while you are driving, you will have a small reserve of power assist for two or three pedal applications but, after that, the brakes will be extremely hard to apply and you must put as much pressure as you can to bring the vehicle to a stop.

The last topic is the Anti-Lock Brakes (ABS). The most efficient braking pressure takes place just before each wheel lock up. When you slam on the brakes in a panic stop and the wheels lock up, causing a screeching sound and leaving strips of rubber on the pavement, you do not stop the vehicle nearly as short as it is capable of stopping. Also, while the wheels are locked up, you loose all steering control so that , if you have an opportunity to steer around the obstacle, you will not be able to do so. Another problem occurs during an extended skid is that you will burn a patch of rubber off the tire which causes a “flat spot” on the tread that will produce an annoying thumping sound as you drive.

Anti-lock brake systems solve this lockup problem by rapidly pumping the brakes whenever the system detects a wheel that is locked up. In most cases, only the wheel that is locked will be pumped, while full braking pressure stays available to the other wheels. This effect allows you to stop in the shortest amount of time while maintaining full steering control even if one or more wheels are on ice. The system uses a computer to monitor the speed of each wheel. When it detects that one or more wheels have stopped or are turning much slower than the remaining wheels, the computer sends a signal to momentarily remove and reapply or pulse the pressure to the affected wheels to allow them to continue turning. This “pumping” of the brakes occurs at tem or more times a second, far faster then a human can pump the brakes manually. If you step on the brakes hard enough to engage the anti-lock system, you may feel a strong vibration in the brake pedal. This is a normal condition and indicates that the system is working; however, it can be disconcerting to some people who don’t expect it. If your vehicle has anti-lock brakes, read your owner’s manual to find out more about it.

The system consists of am electronic control unit, a hydraulic actuator, and wheel speed sensors at each wheel. If the control unit detects a malfunction in the system, it will illuminate an ABS warming light on the dash to let you know that there is a problem. If there is a problem, the antilock system will not function but the brakes will otherwise function normally.

3.Friction materials

Brake shoes and pads are constructed in a similar manner. The pad or shoe is

composed of a metal backing plate and a friction lining. The lining is either bonded (glued) to the metal, or riveted. Generally, riveted linings provide superior performance, but good quality bonded linings are perfectly adequate.

Friction materials will vary between manufacturers and type of pad and the material compound may be referred to as: asbestos, organic, semi-metallic, metallic. The difference between these compounds lies in the types and percentages of friction materials used, material binders and performance modifiers.

Generally speaking, organic and non-metallic asbestos compound brakes are quiet, easy on rotors and provide good feel. But this comes at the expense of high temperature operation, so they may not be your best choice for heavy duty use or mountain driving. In most cases, these linings will wear somewhat faster than metallic compound pads, so you will usually replace them more often. But, when using these pads, rotors tend to last longer.

Semi-metallic or metallic compound brake linings will vary in performance based on the metallic contents of the compound. Again, generally speaking, the higher the metallic content, the better the friction material will resist heat. This makes them more appropriate for heavy duty applications, but at the expense of braking performance before the pad reaches operating temperature. The first few applications on a cold morning may not give strong braking. Also, metallic and semi-metallic are more likely to squeal. In most cases, metallic compounds last longer than non-metallic pads, but they tend to cause more wear on the rotors. If you use metallic pads, expect to replace the rotors more often.

When deciding what type of brake lining is right for you, keep in mind that today's modern cars have brake materials which are matched to the expected vehicle＇s performance capabilities. Changing the material from OEM specification could adversely affect brake feel or responsiveness. Before changing the brake materials, talk to your dealer or parts supplier to help decide what is most appropriate for your application. Remember that heavy use applications such as towing, stop and go driving, driving down mountain roads, and racing may require a change to a higher performance material.

Some more exotic materials are also used in brake linings, among which are Kevlar and carbon compounds. These materials have the capability of extremely good performance for towing, mountain driving or racing. Wear characteristics can be similar to either the metallic or the non-metallic linings, depending on the product you

buy. Most race applications tend to wear like metallic linings, while many of the street applications are more like the non-metallic

制动系统

1. 刹车：鼓与盘

制动技术，就像悬浮技术和燃料系统技术，已走过了漫长的道路

1）鼓式制动器

早在后时代，手杠杆的汽车制动系统用鼓装在所有的四个车轮。它们被称为鼓式制动器的组成部分，因为装在圆鼓上，随着车轮旋转。里面是一套系统，当刹车踏板被按下时，会迫使系统对鼓和车轮速度减缓。流体被用来促使刹车踏板到运动的制动系统的运动，而所用的离合器片本身与一个耐热摩擦材料相似，。

这一基本设计能力的表明，在大多数情况下，它有一大缺陷。高压下的制动条件，想在陡峭的山上降低沉重的负荷或反复高的速度缓慢，鼓式制动器往往会褪色，失去效力。通常这褪色是由于太多的热量累积与鼓。记得的原则，涉及制动转向动能（车轮运动）到热能（热）。基于这个原因，鼓式制动器的操作，他们能吸收产生的热量可以减缓车辆的车轮。可有令人不安之处，一旦制动元件本身饱和，他们失去停止车辆的能力。

2）盘式制动器

盘式制动器用于大多数车的前轮和一些车的四个轮子。制动盘依附于轮毂上，随轮胎一起转动。当司机刹车时，主缸的液压用于推动摩擦衬料，制动钳夹紧制动盘，从而使车停下来。

在盘式制动器中，制动盘通常由铸铁构成。毂可以被制造成一片，和车轮在一起；或者分成两部分。盘式制动器的每一个面都有机械闸。一块保护板连接在转向装置上，以防转子受到公路磨损。盘式制动器可以是全封闭的，也可能是中空的。中空的制动器在闸与闸表面之间有冷却的铸件。这种结构增加了制动器铸

件的冷却面积。当制动鼓移动时，盘式制动器中风扇的转动增加了空气循环和制动的冷却效率。由于盘式制动器的冷却效能，即便要求苛刻，盘式制动器也不会被淘汰。

液压和摩擦部分集中在一个制动钳。制动钳集中跨越毂和制动盘的直径外部。当制动闸启用，活塞的压力通过夹钳的蹄片作用制动盘。由于同样的液压通过施用作用在制动盘的两面，制动盘不会由于施用的激烈或耐久而出现变形。制动钳的设计多种多样，但通常由两种主要类型：浮钳盘式和定钳盘式。定钳盘是固定安装在车桥上，浮钳盘式是可以旋转也可以沿制动盘轴线方向移动。

许多新型汽车采用浮钳盘式制动器设计。这种设计采用一个液压活塞和一个制动钳，使其能够在施用时飘移和滑动。飘移设计在图钉或螺柱上“飘移”。在滑动设计中，卡钳在机器表面滑动。这两种设计基本上以同样的方式起作用。

在单活塞飘移卡钳中，单活塞卡钳集中来源于一个单独的铸件。此铸件包含铸件内侧一个大活塞孔，内侧指的是当卡钳发动时汽车中心线附近的铸件一侧。流体入口的洞和分压闸门洞都在卡钳的内侧，直接与活塞口相连。

制动钳气缸包括一个活塞和封口。封口有一个矩形十字部分。这一部分在气缸的一个槽里。这个封口在活塞直径外围，在活塞和气缸之间提供一个液压封口。这个矩形封口通过分次施用自动调节，清理制动盘，蹄片和连接之间的部分。当制动器施用，制动钳封口就会由于液压和气缸槽里的活塞内直径偏离方向。当液压释放，封口释放，并回到它原始的矩形，当活塞作用于气缸内从而清理其内部。

制动钳衬料磨损，活塞开始运动使封口偏离；活塞因此在封口中滑动以补偿衬料磨损。

活塞的顶端有一个封口灰尘装置。许多制动钳里的活塞都是钢材料，精确的底面，铬板制成，表面坚硬耐久。有些大规模制造中用塑料活塞。这种材质比钢轻，提供一个较轻的制动闸系统。这种塑料活塞，绝缘性好，防止热气传输到制动液中。每个制动钳包括两个蹄片和一些衬料。他们由一个金属踏板蹄片，衬料由蹄片铆接在转子一边的制动钳上。一个蹄片和一些衬料叫做内侧衬料，因为它在车中心线的附近。另一个边由外侧蹄片和衬料组成。

制动器的施用和释放引起了活塞和制动钳的轻微运动。在制动器的释放作用下，活塞和制动钳处于释放位置。在释放位置，蹄片作用时离制动盘表面不远。当制动衬料磨损时，活塞脱离制动钳，制动钳回到和插销与车距离相同的位置。这样，制动钳集中在蹄片的内外侧，衬料通过线路的长度和转子表面有相同的关系。

2.液力制动系的其它部分:

1）比例阀或平衡阀

这种阀安装在主缸和后轮之间。这些阀用于调节分配到前后轮制动管路的油压，而这些压力的大小取决于驾驶员制动的强度。制动越急促，则汽车的重心越靠近前轮，有些情况下，甚至能导致后轮抬起，出现点头现象。这些阀的设计用来更正前轮压力，减少后轮压力使车很难停下来。这样可以减少后轮被锁死的机率。

2）差压阀

这种阀通常安装于主缸的下面，当它检测到故障时，这种阀就能打开制动警示灯。它会测量来自主缸两部分的压力并且比较它们。因为它安装在平衡阀和比例阀的前面，它检测到的两个压力应该是相等的。如果检测到的压力不同，那就是说系统中某部分的制动液泄漏。

3）组合阀

如图所示的组合阀。就是比例阀和差压阀组合成的一个整体。

驻车制动（有称应急制动）系统通过一套与操纵手柄或踏板相连的钢缆来操纵后轮制动器。这套系统是机械式的，且与液压系统并联，从而保证在整个液压制动系统失灵的情况下汽车也能实现制动。

在鼓式制动器中，安装在后轮制动器上的钢缆直接与制动蹄相连。它具有使车轮轮缸旁路和间接控制制动器的作用。

安装在后轮的盘式制动器增加了制动系统的复杂性。这其中的两个主要设计为的是增加后部盘式制动器的机械制动性。第一种是应用现有的后轮卡钳，对卡钳活塞里面的机械螺丝锥加一个控制杆。当制动缆线拉动控制杆时，这个螺旋装置就推动活塞作用于踏板，从而旁路掉液压系统，使车停下来。这种制动系主要用单活塞浮动卡钳，如果卡钳是四活塞固定式，那么这个系统不能用。其它系统应用一个安装在轮子后方的完整的制动鼓或制动蹄单元。这个系统中的制动蹄与控制杆连接着被驻车制动拉动着产生制动。制动鼓事实上是后部制动转子的一部分。

制动自动变速器制动停车很少使用。这样势必造成两个问题。最大的问题是刹车缆线往往受到锈蚀，并最终导致制动失效。经常使用制动停车保持缆线清洁功能正常。另一个问题是自我调节机构，对一些制动系统利用停车制动驱动调整制动器。如果停车制动器是从未使用过，那么刹车永远得不到调整。

电力制动助力器直接安装在位于主缸后面的壳体上，与主缸一起直接连接着制动踏板。目的是对制动蹄施加可能的压力为的是哪怕是最大的车可以用最小的力使它停下来。助力器的力来源于发动机的真空。汽车发动机产生的真空作为正常运作下可以免费应用作为动力配件。比如电力助力系统。真空通过助力器中的止回阀进入到助力器中。止回阀是通过一系列的橡胶软管连接着发动机，并作为

一个单向阀使空气进入助力器。助力器是一个空壳被一个橡胶膜分为两个腔。当脚离开制动踏板时这个阀仍然开着为的是两个腔都可以被充满。当踩下制动踏板时，阀门膜片关闭，分开两个腔，而另一个阀打开使空气进入到制动踏板一侧的腔里。这样就提供了助力。动力助力器非常可靠，本身很少出现问题。然而，其它东西可以导致动力助力的损耗。为了得到动力助力，发动机必须运转。如果在你驾驶时发动机关闭或不运转，你必须有两个或三个踏板的小型后备助力装置，尽管如此，制动也会很难实施，你必须施加尽可能大的力量才能使车停下来。

最后的主题就是ABS。发生在每个车轮锁死之前最有效的制动压力。当你在慌乱中急刹车而车轮锁死时，就会发出一声惨叫并在路面上留有橡胶拖印，基本上不能在很短的时间内将车停下来。而且当车轮锁死时，你失去了所有的转向控制，即使你有机会绕过障碍物你也做不到了。另一个情况就是发生在打滑时，就是燃烧轮胎上的一小片橡胶形成胎面平点，所以在驾驶时产生一个极大的声音。

汽车防抱死系统就是系统检测到车轮被锁时通过快速的提供电磁泵来解决

这种被锁问题。在大多数情况下，只有被锁的车轮才能提供，而充足的制动压力作用于其它车轮。这种效果使你可以在很短的时间内停车时还能保持充分的转向控制，即使一个或更多的车轮在冰面上时，这个系统用计算机控制车速，当它检测到一个或更多的车轮已经停止或比余下的车轮转向慢时，计算机就会发出信号立刻再次驱动或减少车轮上的压力来是它们继续转向。这种电磁的制动在一秒中可以发生十次或更多次，比人手动操作制动快很多。如果你踩制动很难实施防抱死系统，你就会感到强烈的振动，这是正常情况并且表明系统正在运转。然尔，对于对这个没有期望的人，可能不关心这个。如果你的车有ABS，阅读你的操作手册，可以查找更多的相关信息。

这个系统包括电子控制单元，液压传动机构，和每个车轮上的车速传感器。如果控制单元检测到故障，它就会点亮ABS警示灯告之系统有问题。如果出现问题，防抱死就不会运转而制动系统将正常运转。

3.摩擦材料

制动蹄片和衬垫以相似的方式构成。衬垫或蹄片用金属板材和摩擦衬料组成。衬料联结（粘贴）或铆接在金属上。一般来说，铆接衬料更具优越性，但是高质量的联结（粘贴）材料同样合适。

摩擦材料因规格，衬垫的类型，材料的复合情况而不同，通常分为：石棉，有机材料，非金属，金属。这些复合物的差异在于它们的类型，摩擦材料所用的百分比，材料黏合剂和调节剂的使用。

一般来说，有机材料和非金属石棉复合制动器声音较低，但这种制动器必须在高温下操纵，因此它们可能不是在运输重物或在山上驾驶的最好选择。在大多

数情况下，这些衬料比金属复合衬垫运转快，因此通常情况下，还是用其它材料代替它们。但是，用这些材料时，车轮更耐用一些。

半金属或金属复合制动衬料因复合的金属不同而不同。一般来说，金属的质量越高，摩擦材料越耐热。这一优点使这种材料使用于运输重物，但前提是要在衬垫到达操纵所需温度前刹车。在寒冷的早晨，这样材料的装置不容易刹车。而且金属和本金属材料更容易发出尖声。在大多数情况下，金属复合衬垫比非金属衬垫耐久性强，但是车轮的损耗较大。如果选用金属衬垫，就要经常更换车轮子。

在决定哪种类型的制动衬料适合时，不妨考虑一下现代汽车的制动材料是与车辆的性能相匹配的。改变国家统一规格的材料反而会影响制动器的感觉或响应。在改变制动器材料之前，和零售商或部分供货商谈谈，请他们帮忙决定哪种衬料更合适。谨记有一些情况，比如拖拉，紧急刹车和快速起步，在坡道上行驶，以及赛事需要高质量的材料。在制动系统中还需要一些额外的材料，比如合成纤维和复合碳。这些材料性能好，使用于拖拉，山路行驶或比赛。磨损性能和金属或非金属衬料相似，取决于所购买的产品。很多赛事要求金属材料，街上行驶需要非金属材料。

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E---MARKETING (From:E--Marketing by Judy Strauss,Adel El--Ansary,Raymond Frost---3rd ed.1999 by Pearson Education pp .G4-G25.) As the growth of https://www.sodocs.net/doc/c14933648.html, shows, some marketing principles never change.Markets always welcome an innovative new product, even in a crowded field of competitors ,as long as it provides customer value.Also,Google`s success shows that customers trust good brands and that well-crafted marketing mix strategies can be effective in helping newcomers enter crowded markets. Nevertheless, organizations are scrambling to determine how they can use information technology profitably and to understand what technology means for their business strategies. Marketers want to know which of their time-ested concepts will be enhanced by the Internet, databases,wireless mobile devices, and other technologies. The rapid growth of the Internet and subsequent bursting of the dot-com bubble has marketers wondering,"What next?" This article attempts to answer these questions through careful and systematic examination of successful e-mar-keting strategies in light of proven traditional marketing practices. （Sales Promotion;E--Marketing；Internet；Strategic Planning ） 1.What is E--Marketing E--Marketing is the application of a broad range of information technologies for: Transforming marketing strategies to create more customer value through more effective segmentation ,and positioning strategies；More efficiently planning and executing the conception, distribution promotion,and pricing of goods,services,and ideas;andCreating exchanges that satisfy individual consumer and organizational customers` objectives. This definition sounds a lot like the definition of traditional marketing. Another way to view it is that e-marketing is the result of information technology applied to traditional marketing. E-marketing affects traditional marketing in two ways. First,it increases efficiency in traditional marketing strategies.The transformation results in new business models that add customer value and/or increase company profitability.

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专业资料 学院： 专业：土木工程 姓名： 学号： 外文出处：Structural Systems to resist (用外文写) Lateral loads 附件：1.外文资料翻译译文；2.外文原文。

附件1：外文资料翻译译文 抗侧向荷载的结构体系 常用的结构体系 若已测出荷载量达数千万磅重，那么在高层建筑设计中就没有多少可以进行极其复杂的构思余地了。确实，较好的高层建筑普遍具有构思简单、表现明晰的特点。 这并不是说没有进行宏观构思的余地。实际上，正是因为有了这种宏观的构思，新奇的高层建筑体系才得以发展，可能更重要的是：几年以前才出现的一些新概念在今天的技术中已经变得平常了。 如果忽略一些与建筑材料密切相关的概念不谈，高层建筑里最为常用的结构体系便可分为如下几类： 1.抗弯矩框架。 2.支撑框架，包括偏心支撑框架。 3.剪力墙，包括钢板剪力墙。 4.筒中框架。 5.筒中筒结构。 6.核心交互结构。 7. 框格体系或束筒体系。 特别是由于最近趋向于更复杂的建筑形式，同时也需要增加刚度以抵抗几力和地震力，大多数高层建筑都具有由框架、支撑构架、剪力墙和相关体系相结合而构成的体系。而且，就较高的建筑物而言，大多数都是由交互式构件组成三维陈列。 将这些构件结合起来的方法正是高层建筑设计方法的本质。其结合方式需要在考虑环境、功能和费用后再发展，以便提供促使建筑发展达到新高度的有效结构。这并

不是说富于想象力的结构设计就能够创造出伟大建筑。正相反，有许多例优美的建筑仅得到结构工程师适当的支持就被创造出来了，然而，如果没有天赋甚厚的建筑师的创造力的指导，那么，得以发展的就只能是好的结构，并非是伟大的建筑。无论如何，要想创造出高层建筑真正非凡的设计，两者都需要最好的。 虽然在文献中通常可以见到有关这七种体系的全面性讨论，但是在这里还值得进一步讨论。设计方法的本质贯穿于整个讨论。设计方法的本质贯穿于整个讨论中。 抗弯矩框架 抗弯矩框架也许是低，中高度的建筑中常用的体系，它具有线性水平构件和垂直构件在接头处基本刚接之特点。这种框架用作独立的体系，或者和其他体系结合起来使用，以便提供所需要水平荷载抵抗力。对于较高的高层建筑，可能会发现该本系不宜作为独立体系，这是因为在侧向力的作用下难以调动足够的刚度。 我们可以利用STRESS，STRUDL 或者其他大量合适的计算机程序进行结构分析。所谓的门架法分析或悬臂法分析在当今的技术中无一席之地，由于柱梁节点固有柔性，并且由于初步设计应该力求突出体系的弱点，所以在初析中使用框架的中心距尺寸设计是司空惯的。当然，在设计的后期阶段，实际地评价结点的变形很有必要。 支撑框架 支撑框架实际上刚度比抗弯矩框架强，在高层建筑中也得到更广泛的应用。这种体系以其结点处铰接或则接的线性水平构件、垂直构件和斜撑构件而具特色，它通常与其他体系共同用于较高的建筑，并且作为一种独立的体系用在低、中高度的建筑中。

2019年车辆工程专业毕业论文_外文翻译1.doc

Drive force control of a parallel-series hybrid system Abstract Since each component of a hybrid system has its own limit of performance, the vehicle power depends on the weakest component. So it is necessary to design the balance of the components. The vehicle must be controlled to operate within the performance range of all the components. We designed the specifications of each component backward from the required drive force. In this paper we describe a control method for the motor torque to avoid damage to the battery, when the battery is at a low state of charge. Society of Automotive Engineers of Japan, Inc. and Elsevier Science B.V. All rights reserved. 1. Introduction In recent years, vehicles with internal combustion engines have increasingly played an important role as a means of transportation, and are contributing much to the development of society. However, vehicle emissions contribute to air pollution and possibly even global warming, which require effective countermeasures. Various developments are being made to reduce these emissions, but no further large improvements can be expected from merely improving the current engines and transmissions. Thus, great expectations are being placed on the development of electric, hybrid and natural gas-driven vehicles. Judging from currently applicable technologies, and the currently installed infrastructure of gasoline stations, inspection and service facilities, the hybrid vehicle, driven by the combination of gasoline engine and electric motor, is considered to be one of the most realistic solutions. Generally speaking, hybrid systems are classified as series or parallel systems. At Toyota, we have developed the Toyota Hybrid System (hereinafter referred to as the THS) by combining the advantages of both systems. In this sense the THS could be classified as a parallel-series type of system. Since the THS constantly optimizes engine operation, emissions are cleaner and better fuel economy can be achieved. During braking, Kinetic energy is recovered by the motor, thereby reducing fuel consumption and subsequent CO 2 emissions. Emissions and fuel economy are greatly improved by using the THS for the power train system. However, the THS incorporates engine, motor, battery and other components, each of which has its own particular capability. In other words, the driving force must be generated within the limits of each respective component. In particular, since the battery output varies greatly depending on its level of charge, the driving force has to be controlled with this in mind. This report clarifies the performance required of the respective THS components based on the driving force necessary for a vehicle. The method of controlling the driving force, both when the battery has high and low charge, is also described. 2. Toyota hybrid system (THS) [1,2] As Fig. 1 shows, the THS is made up of a hybrid transmission, engine and battery. 2.1. Hybrid transmission The transmission consists of motor, generator, power split device and reduction gear. The power split device is a planetary gear. Sun gear, ring gear and planetary carrier are directly connected to generator, motor and engine, respectively. The ring gear is also connected to the reduction gear. Thus, engine power is split into the generator and the driving wheels. With this type of mechanism, the