制动系统英文翻译

1、 本科毕业论文（设计）翻译资料论文题目CA1145P1货车制动系统设计及强度分析 班 级 姓 名范庆尧 院（系）汽车工程学院 导 师刘涛 制动系统鼓式制动器鼓式制动器的制动是由一组制动蹄或者制动衬片压紧旋转制动鼓的内表面而引起的摩擦。制动鼓和旋转的车轮相连接。伺服系统设计鼓式制动器,由于制动蹄铰接的方式,可以有一个“自动伺服”的特点。这使得在不增加驾驶者额外体力的情况下增加制动力，因为旋转的制动鼓会拖拽周围的制动蹄，从而加大了使他们靠在一起的力。在后制动器上只有一个蹄有这样的特性。（前鼓式制动器也可能使用两个驱动轮缸，这样两个蹄都可以利用伺服特性了，当然这也增加了前轴制动力，需要弥补向前转移的

2、载荷，与此同时也要避免后轮提前抱死。伺服现象可以用来制造一个非常大的制动作用(如大型商用车辆的后轴),但它确实降低了司机对制动的敏感度。(盘式制动器由于衬块垂直地作用于制动盘而没有自动伺服效果)。优势鼓式制动器仍使用在现代汽车中，因为它在技术和成本方面更占优势。驻车制动时用鼓式制动器结构简单。他们通常应用于后轮，因为大部分制动作用是由前轮产生的,因此后轮制动产生的热量明显减少。鼓式制动器有时也安装在后轮以盘式制动器作为主要刹车的汽车上，起到驻车和紧急制动的作用。在这种情况下,小型制动鼓通常是安装在刹车盘上或直接作为刹车盘的一部分。丰田普锐斯，一款技术先进的混合动力汽车，其后轮就采用鼓式制动器。

3、(4轮皆盘式使用在一些特定市场混合动力汽车依靠能量回收，电动发电机，可见再生制动技术等大大减少日常制动系统的磨损)。缺点鼓式制动器内部的制动蹄有一个特定的缺点：长时间急剧制动时会使得制动鼓温度升高，其直径会由于材料的膨胀而变大，制动蹄必须被更用力的压紧来获得有效的制动作用。这被称为制动失效,可能导致司机恐慌，极端情况下甚至导致制动失效。在正常驾驶条件下，很少被注意到,特别是安装的制动鼓尺寸适宜的时候。庞蒂亚克GTO的汽车因其使用较小尺寸的制动鼓而常被人们提起。刹车片在嵌入刹车片过程中，将高摩擦的刹车片材料嵌入到制动盘中，同事保证磨损均匀。虽然人们普遍认为是刹车片材料与制动盘表面金属接触才使汽车

4、停下的，但其实是刹车片内部一层很薄的材料产生了半液体摩擦边界，从而产生了实际的制动力。当然，制动盘磨损的快慢取决于所用材料的特性。材料磨损特性的好坏是由性能和寿命之间的权衡来判定的。刹车片必须定期更换，大多数汽车都安装了报警装置，提醒驾驶者该更换刹车片了。有的是利用一片薄金属片，当刹车片变得太薄时，引起制动尖叫。另一些将薄金属片嵌入刹车片材料中，当刹车片变太薄时，会关闭电路，并点亮警示灯。更高级的汽车可能会使用电子传感器。虽然几乎所有的公路车辆每个制动钳仅有两个制动衬块，但赛车卡钳可利用多达6个制动衬块，将不同的摩擦特性交错布置，以获得最佳的性能。早期的制动衬块和制动蹄含有石棉。当修理老式汽车

5、的制动器时，一定要小心，不要吸入制动钳或制动鼓中的灰尘。制动尖叫有时当施加制动时，会出现很大的噪声或者是高音调的尖叫。大部分制动尖叫是由于制动器部件尤其是制动衬块和制动盘的振动（共振不稳定）产生的。这种类型的制动尖叫不会对制动效能产生负面影响。一些简单的技术，比如将衬片倒角，在制动钳和制动衬块之间加润滑脂或者涂胶，在衬块背板上粘贴绝缘体（阻尼材料）等，可以减轻制动尖叫现象。很多时候，寒冷的天气加上清晨较大的湿度（露水）可能会夹具制动尖叫问题，尤其是当衬片达到常规操作温度时，甚至会制动失效。然而也有些衬片磨损指示器被设计成当衬片需要更换时发出尖叫。整体看来，制动尖叫会给车辆内的乘客、路人、行人等

6、带来烦扰，尤其是对那些以更舒适安静为设计目标的车辆。因此整车NVH（噪声，振动，不平顺性）性能是当今汽车制造商最重要的考虑因素之一。制动器中的灰尘也可能引起制动尖叫。有许多商业制动器清洁产品，可用来清除制动器中的灰尘和污染物。一些高性能制动衬块，比如鹰牌性能衬块，在使用过程中会一直尖叫，但这并不表示有问题 。除了制动尖叫带来的噪音之外，制动器也可能出现制动抖动或颤抖的现象。制动尘埃当施加制动力时，会逐渐地从制动衬块上磨掉少许的材料。这些碎屑被称为“制动粉尘”，通常会沉积在制动系统和周围的车轮中。制动尘埃若不清除，将会严重损害大多数轮胎的使用。不同的制动摩擦片配方会产生不同数量的尘埃，有些配方相

7、对于其他的更具破坏性。我们都知道踩下制动踏板会降低车速至停车，但这是怎么发生的呢？车辆是如何将你退步的力量传递到车轮上的呢？它是如何将力放大到足以让像汽车那么大的物体停下来的呢？典型制动系统的布置当你踩下制动踏板，汽车通过液体将你脚下的力传到制动器上。由于实际上制动器需要的力比人的腿部可以提供的大得多，因而汽车必须放大你脚上的力。有以下两种方式：1 机械优势（杠杆作用）2 液力放大作用制动器靠摩擦力将力传递给车轮，同样，车轮也是靠摩擦将力传递到路面。在我们开始讨论制动系统的组成部分之前，我们将涵盖以下三条原理：1杠杆作用2液压3摩擦鼓式制动器和盘式制动器工作原理是一样的：制动蹄压紧在旋转表面上

8、。在此系统中，这个表面被称为制动鼓。许多汽车后轮采用鼓式制动器，前轮采用盘式制动器。鼓式制动器较盘式的有更多零部件，而且制动效率更低，但它的制造成本较低，更容易安装应急制动装置。在部件如何运作这一版块中，我们将清晰的了解到鼓式制动系统如何运作的，检查紧急制动的设置，并找出需要什么样的行车制动器。鼓式制动器可能看起来很复杂，当你打开一个的时候，可能会被吓一跳。让我们把它拆解开来，并一一解释每个部分。和盘式制动器一样，这个鼓式制动器有2个制动蹄，一个活塞轮缸。但鼓式制动器还有个调整装置，应急制动装置和一些弹簧。当踩下制动踏板，活塞将制动蹄压向制动鼓。当制动蹄接触到制动鼓上时，将会有一种楔入作用，它

9、将起到使制动蹄以更大的力压向制动鼓的作用。楔入作用提供的额外制动力使得鼓式制动器可比盘式制动器使用更小的活塞，然而，由于楔入作用，当释放制动时，必须将制动蹄从制动鼓上拉离。其中一些弹簧就是为了这个原因。其他的弹簧负责使制动蹄还有起作用后的调整臂复位。制动器调整为使鼓式制动器正常工作，制动蹄必须和制动鼓保持接近，但又不接触上它。如果它们离制动鼓太远（例如制动蹄磨损太多），活塞就需要更多的液体来达到这个行程，当踩下刹车时，制动踏板将会更靠近地板。这就是 为何鼓式制动器需要自动调整装置的原因。当制动衬片磨损时，制动蹄和鼓之间将会形成很大间隙。每次停车的背后，都是制动蹄压紧制动鼓。当间隙大到一定程度，

10、调整杠杆摇到足够调整齿轮前进一个齿。调整器上有螺纹，就像个螺栓，当它转动时，使其旋开一点点，旋到填补产生的间隙。当制动蹄再次磨损时，调整器继续前进，因而它总是让制动蹄靠近制动鼓。一些汽车的调整装置在施加应急制动时被驱动。当应急制动器长时间不用时，这种类型的调整器也可单独进行调整。要是你用的就是这种类型的调整器的话，你最好至少每周用一次你的应急制动器。维修对鼓式制动器最常需要的维修是更换制动蹄。一些鼓式制动器背面有个观察孔。从那儿你可以看到制动蹄上还有多少材料。当摩擦材料磨损到铆钉的1/32英寸（0.8毫米）时，制动蹄就应该更换了。要是摩擦材料粘接到支承底板上（无铆钉）时，当耐磨材料只剩下1/1

11、6英寸（1.6毫米）时，制动蹄就该更换了。和盘式制动器一样，深些的划痕有时也会损坏制动鼓。如果产生磨损的制动蹄仍被长时间使用的话，连接耐磨材料和衬背的铆钉会透过槽进入制动鼓中。有划伤的制动鼓有的可以通过返工修光处理被修复。鼓式制动器有个最大允许直径，而盘式制动器有个最小允许厚度。由于接触表面是制动鼓的内表面，当鼓式制动器材料磨损时，直径就会变大。盘式制动器的主要组成部分是：1刹车片2卡钳，其中包含一个活塞3转子，安装在轮毂上盘式制动器的部件盘式制动器和自行车上的制动器很像。自行车制动器有一个卡钳，它压紧固联车轮上的刹车片。在盘式制动器中，刹车片压紧转子而不是车轮，并且力是通过液压传递地而不是通

12、过线缆。刹车片和制动盘之间的摩擦使得制动盘减速。行驶中的汽车具有一定的动能，制动器要想使车辆停下就必须从车上移除这些能量。制动器是如何做到这点的呢？每次停车时，制动器都会将动能转化成衬片和制动盘之间摩擦产生的热能。大多数汽车盘式制动器是通风盘式。盘式制动器通风孔通风盘制动器在制动盘的两侧有一组叶片，将空气泵过制动盘以提供冷却。自动调整制动器单活塞浮动钳盘式制动器有自动定心和自动调整功能。卡钳能够从一侧滑到另一侧，以致每次施加制动时，他都将移动到中心处。另外，由于没有弹簧将衬片拉离制动盘，衬片始终和转子保持轻微接触（事实上，橡胶活塞密封圈和转子的任何摇晃都可能将衬片从转子上拉离一小段距离）。这点

13、很重要，因为制动器中的活塞直径比主缸活塞直径大得多。如果活塞缩回制动器主缸，它将可能需要多次踩下制动踏板，向制动轮缸泵入足够的液体，以使制动衬片压紧。老式汽车有双重或四个活塞固定卡钳设计。转子每一侧有一个活塞（或两个）压紧制动衬片。这种设计已经基本淘汰，因为单缸活塞设计更便宜也更可靠。应急制动四轮全采用全盘式制动器的汽车中，应急制动器必须由独立的机械装置驱动，以防止主制动器失效时，整个制动器都失效。大多数汽车用缆绳来驱动应急制动器。盘式制动器驻车制动有些四轮全盘式制动器的汽车，在后轮轮毂上有一个独立的集成鼓式制动器。这个鼓式制动器只用于应急制动系统，仅由缆绳驱动；没有液压系统参与。其他汽车有个

14、杠杆转动螺杆，或驱动一个凸轮，来压紧盘式制动器中的活塞。动力制动器是如何工作的如果你曾打开过汽车的引擎盖，你可能已经看到了制动助力器。它是个圆的，黑色储罐，安置在汽车发动机舱的后部，驾驶员的一侧。早先，当大部分汽车还是鼓式制动器时，动力制动器还不是真的有必要。鼓式制动器本身就能够起到一些助力作用。现在因为大部分汽车都采用了盘式制动器，至少前轮都是盘式的，他们就需要动力制动器。要不是有这种装置，许多驾驶员驾驶起来，腿部会很累。制动助力器利用发动机提供的真空来放大你的脚施加在制动主缸上的力。真空助力器真空助力器是一个有着自动阀和隔膜的金属罐。一根穿过小罐中心的杆一侧连着制动缸活塞，一侧连着制动踏板

15、。动力制动器中另一个重要的部件是单向阀。Braking SystemsDrum brakeA drum brake is a brake in which the friction is caused by a set of shoes or pads that press against the inner surface of a rotating drum. The drum is connected to a rotating wheel. Servo design Drum brakes, depending on the way the shoes are hinged, can

16、have a self-servo characteristic. This increases stopping power without any additional effort by the driver because the rotation of the drum drags the shoes around with it, increasing the force holding them together. In rear brakes only one shoe will have this characteristic. Front drum brakes may u

17、se two actuating cylinders which allow both shoes to utilize the servo characteristic and which also increase the front axle braking force, required to compensate for forward weight shift and also to avoid premature rear wheel locking. Servo action can be used to make a very powerful brake (as on th

18、e rear axles of large commercial vehicles), but it does reduce the ability of the driver to modulate the brakes sensitively. (The disc brake has no self-servo effect because the pads act perpendicularly to the rotating disc.) Advantages Drum brakes are still used in modern cars. There can be enginee

19、ring and cost advantages. Drum brakes allow simple incorporation of a parking brake. They are often applied to the rear wheels since most of the stopping happens in the front of the vehicle and therefore the heat generated in the rear is significantly less. Drum brakes are also occasionally fitted a

20、s the parking (and emergency) brake even when the rear wheels used disk brakes as the main brakes. In this situation, a small drum is usually fitted within or as part of the brake disk. An advanced technology hybrid car using drum rear brakes is the Toyota Prius. (4-wheel discs are used in certain m

21、arkets - Hybrid vehicles greatly reduce everyday wear on braking systems owing to their energy recovery motor-generators, see regenerative braking). Disadvantages Drum brakes with internal shoes have a particular disadvantage; when the drums are heated by hard braking the diameter of the drum increa

22、ses due to the expansion of the material and the brakes must be further depressed to obtain effective braking action. This is known as brake fade and can lead to driver panic and brake failure in extreme circumstances. Under normal driving conditions it is seldom noticed, especially when drums of ap

23、propriate size are fitted. The Pontiac GTO is one vehicle often cited as having undersized drums.Brake pads The brake pads are designed for high friction with brake pad material embedded in the disc in the process of bedding while wearing evenly. Although it is commonly thought that the pad material

24、 contacts the metal of the disc to stop the car, the pads work with a very thin layer of their own material and generate a semi-liquid friction boundary that creates the actual braking force. Of course, depending on the properties of the material, disc wear could be faster or slower than with other

25、pads. The properties that determine material wear involve trade-offs between performance and longevity.The brake pads must be replaced regularly, and most are equipped with a method of alerting the driver when this needs to take place. Some have a thin piece of soft metal that causes the brakes to s

26、queal when the pads are too thin, while others have a soft metal tab embedded in the pad material that closes an electric circuit and lights a warning light when the brake pad gets thin. More expensive cars may use an electronic sensor. Although almost all road-going vehicles have only two brake pad

27、s per caliper, racing calipers utilise up to six pads, with varying frictional properties in a staggered pattern for optimum performance. Early brake pads (and shoes) contained asbestos. When working on an older cars brakes, care must be taken not to inhale any dust present on the caliper (or drum).

28、Brake squeal Sometimes a loud noise or high pitch squeal occurs when the brakes are applied. Most brake squeal is produced due to vibration (resonance instability)of the brake components especially the pads and discs. This type of squeal does not negatively affect brake stopping performance. Some si

29、mple techniques like adding chamfers to linings, greasing or gluing the contact between caliper and the pads (finger to backplate, piston to backplate), bonding insulators (damping material) to pad backplate, etc might help reduce squeal. Many times cold weather combined with high early morning humi

30、dity (dew) could make the brake squeal worse and vanishes when the lining reaches regular operating temperatures. However, some lining wear indicators are also designed to squeal when the lining is due for replacement. Overall brake squeal can be annoying to the vehicle passengers, passerby, pedestr

31、ians, etc especially as vehicles are designed to be more comfortable and quieter. Hence vehicle NVH (Noise, Vibration and Harshness) is one of the important priorities for todays vehicle manufacturers. An age-old trick is to put a small amount of copper slip (copper grease) onto the back of the pads

32、 where they contact the brake caliper piston and on the pad shims, if present. While this will normally stop the squeal, getting grease on the pads or disks will affect braking performance. Dust on the brakes may also cause squeal; there are many commercial brake cleaning products that can be used t

33、o remove dust and contaminants from the brakes. Some high-performance brake pads, such as Hawk Performance pads, will always squeal during operation, and this does not indicate a problem. Apart from noise generated from squeal, brakes may also develop a phenomenon called brake judder or shudder.Brak

34、e Dust When braking force is applied, small amounts of material are gradually ground off the brake pads. This material is known as brake dust and usually deposits itself on the braking system and the surrounding wheel. Brake dust can badly damage the finish of most wheels if not washed off. Differen

35、t brake pad formulations create different amounts of dust, and some formulations are much more damaging than others.We all know that pushing down on the brake pedals lows a car to a stop. But how does this happen? How does your car transmit the force from your leg to its wheels? How does it multiply

36、 the force so that it is enough to stop something as big as a car? Layout of typical brake systemWhen you depress your brake pedal, your car transmits the force from your foot to its brakes through a fluid. Since the actual brakes require a much greater force than you could apply with your leg, your

37、 car must also multiply the force of your foot. It does this in two ways: 1 Mechanical advantage(leverage) 2 Hydraulic force multiplicationThe brakes transmit the force to the tires using friction, and the tires transmit that force to the road using friction also. Before we begin our discussion on t

38、he components of the brake system, well cover these three principles: 1 Leverage 2 Hydraulics 3 FrictionDrum brakes work on the same principle as disc brakes: Shoes press against a spinning surface. In this system, that surface is called a drum.Many cars have drum brakes on the rear wheels and disc

39、brakes on the front. Drum brakes have more parts than disc brakes and are harder to service, but they are less expensive to manufacture, and they easily incorporate an emergency brake mechanism. In this edition of How Stuff Works, we will learn exactly how a drum brake system works, examine the emer

40、gency brake setup and find out what kind of servicing drum brakes need.The drum brake may look complicated, and it can be pretty intimidating when you open one up. Lets break it down and explain what each piece does. Like the disc brake, the drum brake has two brake shoes and a piston. But the drum

41、brake also has an adjuster mechanism, an emergency brake mechanism and lots of springs. When you hit the brake pedal, the piston pushes the brake shoes against the drum. As the brake shoes contact the drum, there is a kind of wedging action, which has the effect of pressing the shoes into the drum w

42、ith more force. The extra braking force provided by the wedging action allows drum brakes to use a smaller piston than disc brakes. But, because of the wedging action the shoes must be pulled away from the drum when the brakes are released. This is the reason for some of the springs. Other springs h

43、elp hold the brake shoes in place and return the adjuster arm after it actuates.Brake Adjuster For the drum brakes to function correctly, the brake shoes must remain close to the drum without touching it. If they get too far away from the drum (as the shoes wear down, for instance), the piston will

44、require more fluid to travel that distance, and your brake pedal will sink closer to the floor when you apply the brakes. This is why most drum brakes have an automatic adjuster. As the pad wears down, more space will form between the shoe and the drum. Each time the car stops while in reverse, the

45、shoe is pulled tight against the drum. When the gap gets big enough, the adjusting lever rocks enough to advance the adjuster gear by one tooth. The adjuster has threads on it, like a bolt, so that it unscrews a little bit when it turns, lengthening to fill in the gap. When the brake shoes wear a li

46、ttle more, the adjuster can advance again, so it always keeps the shoes close to the drum. Some cars have an adjuster that is actuated when the emergency brake is applied. This type of adjuster can come out of adjustment if the emergency brake is not used for long periods of time. So if you have thi

47、s type of adjuster, you should apply your emergency brake at least once a week.Servicing The most common service required for drum brakes is changing the brake shoes. Some drum brakes provide an inspection hole on the back side, where you can see how much material is left on the shoe. Brake shoes sh

48、ould be replaced when the friction material has worn down to within 1/32 inch (0.8 mm) of the rivets. If the friction material is bonded to the backing plate (no rivets), then the shoes should be replaced when they have only 1/16 inch (1.6 mm) of material left. Just as in disc brakes, deep scores so

49、metimes get worn into brake drums. If a worn-out brake shoe is used for too long, the rivets that hold the friction material to the backing can wear grooves into the drum. A badly scored drum can sometimes be repaired by refinishing. Where disc brakes have a minimum allowable thickness, drum brakes

50、have a maximum allowable diameter. Since the contact surface is the inside of the drum, as you remove material from the drum brake the diameter gets bigger. The main components of a disc brake are: 1 The brake pads2 The caliper, which contains a piston 3 The rotor, which is mounted to the hub Parts

51、of a disc brakeThe disc brake is a lot like the brakes on a bicycle. Bicycle brakes have a caliper, which squeezes the brake pads against the wheel. In a disc brake, the brake pads squeeze the rotor instead of the wheel, and the force is transmitted hydraulically instead of through a cable. Friction

52、 between the pads and the disc slows the disc down.A moving car has a certain amount of kinetic energy and the brakes have to remove this energy from the car in order to stop it. How do the brakes do this? Each time you stop your car, your brakes convert the kinetic energy to heat generated by the f

53、riction between the pads and the disc. Most car disc brakes are vented.Disc brake ventsVented disc brakes have a set of vanes, between the two sides of the disc that pumps air through the disc to provide cooling. Self-Adjusting Brakes The single-piston floating-caliper disc brake is self-centering a

54、nd self-adjusting. The caliper is able to slide from side to side so it will move to the center each time the brakes are applied. Also, since there is no spring to pull the pads away from the disc, the pads always stay in light contact with the rotor (the rubber piston seal and any wobble in the rot

55、or may actually pull the pads a small distance away from the rotor). This is important because the pistons in the brakes are much larger in diameter than the ones in the master cylinder. If the brake pistons retracted into their cylinders, it might take several applications of the brake pedal to pump en