制动器的英文版及翻译(2)

process at this time is completely the same with conventional braking system braking process. In braking process, when the electronic control detects that the wheels primarily tend to embrace dies according to the wheel speed sensors of the wheel speed signal input, ABS came into the braking anti-lock process. For example, when the electronic control unit judges the front-right wheel tends to embrace, the electronic control unit will make control scrape the dynamic pressure front-right wheel failure into liquid solenoid valves electricity, make the fluid electromagnetic valve closed, brake main cylinder output brake fluid no longer enter into brake wheel cylinder, right now, right at the end of a fluid electromagnetic valve still energized and closed, the right brake wheel cylinder brake fluid also won't outflow, the right brake wheel cylinder scraping dynamic pressure stays certain, and other arms tend to be dead wheel with still brake pressure braking main cylinder and the increase of output pressure increases; If the right brake wheel cylinder brake pressure keep certain, the electronic control unit front-right wheel failure still tend to judge lock, the electronic control unit and move out liquid solenoid valves also electrify into a state of opening, the part right brake wheel cylinder brake wave will pass is open from fluid electromagnetic valve flow back to liquid container, make right brake wheel cylinder brake pressure holding diminishes quickly front-right wheel failure will start to eliminate death trend, with the right brake wheel cylinder brake pressure decreases, the front-right wheel under the action of inertia force will speed up gradually; accelerate gradually When the electronic control device determines the lock front-right wheel failure to completely eliminate according to the wheel speed sensors input signal, the electronic control unit makes right into the fluid electromagnetic valve and a liquid solenoid valves are without electricity, make into fluid electromagnetic valve to open, use liquid into closed electromagnetic valve, also make electric pump operation, energized to brake wheel cylinder pump brake fluid, output by brake main cylinder brake fluid electromagnetic valve into the right brake wheel cylinders, make right brake wheel cylinder brake pressure increased rapidly, opening up a front-right wheel failure and slow rotation. ABS control the sliding rate of wheels which tend to be locked through holding the brake force of wheels that tends to be locked repeatedly ,adhesion coefficient is in peak within the scope of the sliding rate, until the bus speed reduced to very low or brake main cylinder pressure no longer tend to be locked. Brake pressure to adjust cycle of frequency can reach 3 ~ 20HZ. In the ABS each has on the fluid and the fluid electromagnetic valve in corresponding at each brake wheel cylinder, but by the electronic control device to control, therefore, respectively, the brake wheel cylinder brake pressure can be independently adjustment so that four wheels are not occur braking lock phenomenon. Although various ABS structure form and working process is not exactly the same, are based on the brake holding pressure adaptive cycle adjustment of wheel which tends to be locked, to prevent the controlled wheels holding in death occurred when brake.

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3.3、 ABS function

The braking performance is one of main auto performance, it is also related to the security of driving. Evaluate the braking performance of a car , the basic index is brake acceleration ,braking distance and direction of braking time and braking stability.

Braking stability points to that the vehicle can still be specified in the direction of auto brake when driving in the direction of track. If cars proceed high-speed brake (especially when emergency brake) and make the wheel fully embrace die, it is very dangerous. If front wheel is locked, it will make cars lose steering ability. If the rear wheel is locked, it will appear to swing tail or switching (running deviation, sideslip) especially in the road is all wet slippery case, it will cause the traffic safety great harm. Automobile braking force depends on the brake friction, but the braking force which can make the car brake to slow, and also restricted by ground adhesion coefficient. When brake produces braking force increases to certain value, the tires will appear slipping on the ground. Its sliding rate

δ = (Vt - Va) / Vt x 100% δ: delta - sliding rate; Vt - theoretical speed of the car; Va - the actual speed of the car.

According to the experiments confirm, when wheel sliding rate delta range from 15% to 20% , the ground adhesion coefficient reach maximum, therefore, in order to get the best braking effect, we must control the slip rate in 15% ~ 20% range.

ABS function will namely decrease the brake force when the wheels will embrace dies, , and when the wheel will not hold died and increase braking force, so repeated action, braking effect is the best.

3.4、The problems needing attention when ABS is used

(1) After replace brake or replace hydraulic brake system components, it should exhaust the air in the brake pipe, lest affect braking system work normally.

(2)The car equipped with ABS should be replaced every year. Otherwise, brake fluid hygroscopic is very strong, water will not only reduce the boiling point to make it easy to produce corrosion, and still can cause braking performance recession. (3) To examine ABS braking system should pull power firstly.

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制动系简介

制动器通过摩擦的形式吸收运动车辆所具有的能量而起作用。并且将这些能量转化为热能。有两种类型的制动器，即鼓式制动器和盘式制动器。在一辆车上，可安装其中一种类型的制动器，也可同时安装两种类型的制动器。但在使用两种类型制动器的车上，盘式制动器通常安装在前轮。

在鼓式和盘式两种制动系统中，都利用液压系统实现制动，液压系统将制动器踏板与每个车轮上的制动器构件连接起来。 1 鼓式制动

鼓式制动器含有一对（副）半圆形的制动蹄，制动蹄位于制动鼓内并安装固定于底板上。 制动鼓与车轮固定连接，随车轮一起转动。每个制动蹄的一端安装于枢轴上，而另一端在弹簧的作用下与液压缸内的活塞保持接触。（在前制动器内，通常用两个液压缸，以便均衡由两制动蹄产生的压力。（如图7.1所示）

每个制动蹄的表面都覆盖有制动衬垫，制动衬垫（制动蹄摩擦片）产生高的摩擦阻力.（每个制动蹄的表面都覆盖有产生高摩擦阻力的制动蹄摩擦片）。

图7.1 鼓式制动器

1—制动器后盖 2—制动蹄 3—制动衬片 4—弹簧 5—液压缸

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图7.2 液压制动系统的主要组成部分

图7.3 盘式制动器

液压系统包含一个制动主缸和多个位于车轮上的制动轮缸。制动轮缸通过管道与制动主缸相连，并且整个系统都充满液压油。制动主缸中的一个活塞与制动踏板相联，所以当驾驶员踩下制动踏板时，迫使油液向外流到每一个制动轮缸，并使它们的活塞移动。油液将活塞推出液压缸，接着，活塞又推动制动蹄的内端，并将制动蹄挤向位于车轮内的制动鼓。我们说这时制动产生（起作用）。制动蹄对固联于车轮的制动鼓产生的摩擦力，使汽车减速或停止。当允许制动踏板抬起时，液压油返回原处，活塞缩回，安装在每个制动蹄上的弹簧使制动蹄也返回原位。释放制动鼓，此时我们说制动解除。（图7—2）制动器也可以用制动踏板和制动手柄的机械制动装置操纵。 通常惯例是前、后制动器均为液压操纵，同时仅仅利用手柄的辅助机械系统来操纵后制动器。液压操纵的最大优点之一是系统的自动平衡（自动调节），这就意味着所有的四个制动器自动产生相等的压力，而机械传动装置必须经过非常仔细的调整才能达到平衡。当然，

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如果一个制动器上的压力比其他制动器大，那就有汽车制动测滑的危险后制动器的机械传动装置是一套将制动手柄与制动蹄装置连接起来的杠系或缆绳，它们完全独立于液压系统而工作。

鼓式制动器的制动效能将会有减弱的趋势，或称为“制动热衰退”，它是由制动蹄摩擦片和制动鼓过热而引起的。制动衰退一次可影响全部或其中一部分制动器，但不是永久性的（长期的），一旦制动器冷却下来，又恢复到全部效能。然而，除了为使高速行驶的汽车减速而反复使用制动器，或者下陡坡连续制动外，制动（热）衰退是不太可能发生的。下这样的陡坡，更好的办法是（变速器）挂上低档用发动机制动。可通过改进冷却布置，如增加透气通风来减少鼓式制动器受制动热衰退的影响。

2 盘式制动

盘式制动器由钢制圆盘和制动液压轮缸操纵的制动衬块构成。钢制圆盘固定于车轮上并随车轮一起转动。钢盘的一部分装在制动钳内。制动钳有两个制动衬块（钢盘的每侧各一个）和两个液压轮缸（每个制动衬块的外侧各一个）。制动衬块正常情况下由弹簧保持分离，但是当驾驶员踩下制动踏板时，液压缸内的活塞就将制动衬块压向钢盘的侧面。因为制动盘没有被完全包围，制动过程中所产生热的耗散，比从完全包围在制动鼓中的制动蹄上热的耗散更快得多。这就意味着盘式制动器受制动衰退的影响比鼓式制动器更小。（图7.3）

图7.4 ABS制动系统组成示意图

3 ABS

防抱死或防侧滑制动系统的功用是防止车轮在急剧制动中抱死。最大的制动力是正好在车轮抱死滑动之前得到的。这种防滑系统在光滑的表面很有用，如在冰和雪上，在这种表面车轮容易抱死。车轮抱死是危险的，因为这时需要更长的距离才能使汽车停止行驶。 车轮抱死也能导致驾驶员失去对汽车的控制。 系统使用了一个传感器，它能分辨（识别）一个车轮（或一副车轮）即将开始滑动的信息。传感器将信号发送到计算机，计算机向调节器阀发出信号。调节器联入到液压系统，并能瞬间（立刻）释放制动压力，防止车轮抱死.（压力释放非常迅速，驾驶员很难觉察得到。）随后，又再度施加制动压力，直到传感器再次感测到车轮即将抱死为止。因此，系统将车轮保持在尽可能接近抱死的状态，而实际上又

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