制動(dòng)器的英文版及翻譯

1、The BrakesThe brakes function by absorbing in friction the energy possessed by the moving car. In so doing they convert the energy into hear. There are tow types of brakes, the drum brake and the disc brake. Either or both types may be fitted. But where both types are used it is usual for the disc b

2、rakes to be fitted to the front wheels. In both drum and disc brakes, a hydraulic system applies the brakes. The hydraulic system connects the brake pedal to the brake parts at each wheel.1、 Drum BrakesThe drum brake consists of a pair of semicircular brake shoes mounted on a fixed back plate and si

3、tuated inside a drum. This drum is fixed to the road wheel and rotates with it .One end of each shoe is on a pivot and a spring holds the other end in contact with the piston of a hydraulic cylinder,(In front brakes it is usual to use two hydraulic cylinders in order to equalize the pressures exerte

4、d by the shoes, as shown in Fig.7.1)Each shoe is faced with material ,known as brake lining ,which produces high frictional resistance.Fig.7.1 Drum brake1-back plate 2-brake shoe 3-brake lining 4-spring 5-hydraulic cylinderwheel cylindermaster cylinderbrake pedalbrake linedrum brakebrake line meteri

5、ng valveproportioning valvedisc brake caliperFig.7.2 The principal parts of the brake hydraulic sysiemThe hydraulic system comprises a master cylinder and the slave cylinders which are the cylinders on the road wheels. The slave cylinders are connected to the master cylinder by tubing and the whole

6、system is filled with hydraulic fluid .A piston in the master cylinder is connected to the brake pedal, so that when the driver depresses the pedal the fluid is forced out to each slave cylinder and operates their pistons. The fluid pushes the pistons out of their cylinders. They , in turn, push aga

7、inst the inner ends of the brake shoes and force them against the drums in each wheel. We say that the brakes are on. This friction of the shoes against the drums, which are fixed to the road wheels, slows down or stops the car.As the brake pedal is allowed to come up, the hydraulic fluid returns to

8、 its original position, the pistons retract, and a spring attached to each brake shoe returns it also to its original position. Free of the brake drum. Now we say that the brakes are off,(Fig.7.2)The brakes may also be operated by mechanical linkages from the foot pedal and hand brake lever. Common

9、practice is to operate both front and rear brakes hydraulically with a secondary mechanical system operating the rear brakes only from the hand lever. One of the great advantages of hydraulic operation is that the system is self-balancing, which means that the same pressure is automatically produced

10、 at all four brakes, whereas mechanical linkages have to be very carefully adjusted for balance. Of course, if more pressure is put on one of the brakes than on the others there is a danger that the car will skid.The mechanical linkage on the rear brakes is a system of rods or cables connecting the

11、handbrake lever to the brake-shoe mechanism, which work entirely independently of the hydraulic system. Drum brakes are prone to a reduction in the braking effort, known as fade”，caused by the overheating of the brake linings and the drum. Fade can affect all or only some of the brakes at a time, bu

12、t it is not permanent, and full efficiency returns as soon as the brakes have cooled down.However, fading is unlikely to occur except after the brakes have been used repeatedly in slowing the car from a high speed or after braking continuously down a steep hill. Descending such a hill, it would have

13、 been preferable to use engine braking by changing down into a lower gear. Drum brakes can be made less prone to fade by improving the cooling arrangements, by arranging for more air to be deflected over them, for example.2 Disc BrakesThe disc brake consists of a steel disc with friction pads operat

14、ed by slave hydraulic cylinders. The steel disc is attached to the road wheel and rotates with it. Part of this steel disc is enclosed in a caliper. This caliper contains two friction pads, one on each side of the disc, and two hydraulic cylinders, one outside each pad. The pads are normally held ap

15、art by a spring, but when the driver depresses the brake pedal, pistons from the hydraulic cylinders force the pads against the sides of the disc. Because the disc is not enclosed all the way round, the heat generated when the brakes are applied is dissipated very much more quickly than it is from b

16、rake shoes which are entirely enclosed inside a drum. This means that disc brakes are less prone to fade than drum brakes,(Fig.7.3)caliper bolted to suspensionfriction pad網(wǎng)g3、Anti-lock Brake System (ABS)The function of an anti-lock, or anti-skid, braking system is to prevent the wheels from locking

17、under hard braking. Maximum braking force、is obtained/just before the wheels lock and skid. Such anti-skid system ate useful on slippery surfas ice and snow, where the wheels maylock easily. Locked wheels are dangerous because the car needs a much longer distance to stop.Locked wheels also can cause

18、 the driver to lose control.Ufftkchydraulic unitelectronic control unitproportioning valve master cylinder 曲 delay valve speed .sensorbrake boosterA.B.S. warning lamp brake pedal linkageFig.7.4 Parts of an anti-lock brake system (ABS)The system uses a sensor that knows when one wheel (or a pair of w

19、heel) is skidding. (Fig.7.4) The sensor sends a signal to a computer, which signals a modulator valve. The modulator connects into the hydraulic system and can momentarily release the brake pressure and prevent the wheels from locking,(The pressure release is so fast that a driver is seldom aware of

20、 it.) pressure is then reapplied until the sensor again senses that the wheel is about to lock up. Thus, this system keeps the wheels as close to lock up as possible, without actually allowing the wheels to lock up and skid. This is called incipient lock up. Maximum braking occurs at that point. If

21、any part of the system should fail to work, the system goes into a “fail -safe” mode. The brakes operate normally, as they would on a car that is not equipped with ABS. Today , ABS is an optional or standard feature that typically is found on expensive luxury cars and sports cars. In the future, ABS

22、 may be available for all cars.3.1、ABS overviewAnti-lock braking system is using the body of a rubber balloon, while hitting the brakes, will give brake oil pressure, feeding through to the ABS body, using of the air in the middle of the air layer to return the pressure, make wheels evade the locked

23、 points. When the wheel will arrive next locked point, brake oil pressure makes balloon in a repeat function, so can function eight to thirty times in one second equivalent constantly brake, relax, namely, similar to the mechanical braking .Therefore, ABS anti-lock braking system, can avoid the orie

24、ntation losing control , the wheel s lateral sliding coming up and the wheels rubbing on one point with the ground without being locked in the emergency brake, so it can make the brake friction efficiency achieves ninety percent. It also can reduce the braking consumption and prolong the brake wheel

25、 drum, disc and tire twice with the service life of the vehicle in the ABS. On the dry tarmac road or on snowy or on rainy days, the slippery performance reached 80% - 90%, 30% -10%, 15% - 20%. Ordinary braking system on a wet road surface brake, or in the emergency brake, it s easy for wheels to be

26、 locked owing to the braking force exceeds the friction force of the tires and ground. In recent years, the consumers of the vehicle emphasis on the safety , so most of the cars have ABS listed as standard. Without ABS, emergency brake usually cause tire locked, then, the rolling friction becomes sl

27、iding friction, as a result, braking force dramatically decreased. And if front wheels are locked first, the vehicle will lose the steering ability; if the rear tires are first locked, the vehicle is easy to slide laterally , so the direction becomes impossible to control. Through electronic or mech

28、anical control, the ABS system controls the braking fluid pressure at a fast speed to avoid the wheels locked. Insure the tire have the biggest braking force and the turning ability when braking, and make the vehicle have the ability to evade the obstacles in emergency braking. With the rapid develo

29、pment of the automotive industry, safety increasingly become the important basis of that people choose and buy cars. At present the widespread adoption of holding brake system (ABS) that people can fully meet the safety of requirements. Automobile brake prevent embrace system, referred to as the ABS

30、, is to improve the car an important device passive safety. Someone said brake prevent embrace system is auto safety measures relay belts after another major progress. Automobile braking system is the bus passengers safety is the most important relationship to one of the second systems. With the rap

31、id development of the automotive industry, automobile safety for people appeals more and more attention. Automobile brake prevent embrace system, is another major progress to improve the safety.ABS braking system is controlled by automobile microcomputer, when braking, it can keep the wheel rotating

32、 to help driver control vehicle parking safely. The anti-locked braking system detects wheel speed by speed sensor, and then send the wheel speed signals to the microcomputer. The microcomputer controls wheel slipping rate by increasing or decreasing the brake pressure repeatedly according to the in

33、put wheel speed to keep wheel rotate. In braking process, keeping wheel rotate not only ensures the ability of controlling driving direction, but also provides higher brake force than the locked wheel in most circumstances,.3.2、The working principle of ABSIt includes control devices and ABS warning

34、lights, in different ABS system, the structure of brake pressure adjusting device and working principle of electronic control devices are often different, the internal structure and control logic of ABS system usually includes the wheel speed sensors, brake pressure adjusting device, electronic iden

35、tical and so on. In common ABS system, each wheel is installed a rotational speed sensor on the wheel speed, input the signal to electronic control device. The electronic control unit states monitoring and determination according to each wheel speed sensors signal about each wheel movement, and has

36、formed the corresponding control instruction. Brake pressure adjusting device is mainly composed by pressure regulating solenoid valves, electric pump composition and liquid container components compose an independent whole, braking main cylinder and the cylinder brake wheel connected by the brake p

37、ipe. Brake pressure adjusting device is controlled by the electronic unit to control all brake wheel cylinders7 brake pressure. The working process of ABS can be divided into general braking, brake pressure kept brake pressure decrease and brake pressure increase stage. In general braking phase, ABS

38、 doesnt intervene brake pressure control, pressure regulating electromagnetic valve assembly in various into liquid solenoid valves are no electricity and is open, each produced liquid are no electricity and electromagnetic valve is in the closed position, electric pump also operates without electri

39、city, and brake main cylinder to each brake wheel cylinder brake lines are in communication condition, and the brake wheel cylinder to liquid brake lines are in close condition, the brake wheel cylinder brake pressure change with the output pressure brake master cylinder, the braking process at this

40、 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

41、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 outpu

42、t 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 wont outflow, the right brake wheel cylinder scraping dynamic pressure stays certain, and other arms tend

43、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 liqu

44、id 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 t

45、o 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 accord

46、ing 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 operati

47、on, 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 sl

48、iding 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

49、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 indepen

50、dently 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

51、in death occurred when brake.3.3、ABS functionThe 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

52、.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

53、 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

54、 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 rate5 = (Vt - Va) / Vt x 100%& delta - sliding rate;Vt - theoretical speed of the c

55、ar;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 d

56、ecrease 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 usedAfter replace brake or replace hydraulic brake system components, it should

57、 exhaust the air in the brake pipe, lest affect braking system work normally.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 perf

58、ormance recession.To examine ABS braking system should pull power firstly.制動(dòng)系簡(jiǎn)介制動(dòng)器通過(guò)摩擦的形式吸收運(yùn)動(dòng)車(chē)輛所具有的能量而起作用。并且將這些能量轉(zhuǎn)化為熱 能。有兩種類(lèi)型的制動(dòng)器，即鼓式制動(dòng)器和盤(pán)式制動(dòng)器。在一輛車(chē)上，可安裝其中一種類(lèi)型 的制動(dòng)器，也可同時(shí)安裝兩種類(lèi)型的制動(dòng)器。但在使用兩種類(lèi)型制動(dòng)器的車(chē)上，盤(pán)式制動(dòng)器 通常安裝在前輪。在鼓式和盤(pán)式兩種制動(dòng)系統(tǒng)中，都利用液壓系統(tǒng)實(shí)現(xiàn)制動(dòng)，液壓系統(tǒng)將制動(dòng)器踏板與每 個(gè)車(chē)輪上的制動(dòng)器構(gòu)件連接起來(lái)。1鼓式制動(dòng)鼓式制動(dòng)器含有一對(duì)（副）半圓形的制動(dòng)蹄，制動(dòng)蹄位于制動(dòng)鼓內(nèi)并安裝固

59、定于底板上。 制動(dòng)鼓與車(chē)輪固定連接，隨車(chē)輪一起轉(zhuǎn)動(dòng)。每個(gè)制動(dòng)蹄的一端安裝于樞軸上，而另一端在彈 簧的作用下與液壓缸內(nèi)的活塞保持接觸。（在前制動(dòng)器內(nèi)，通常用兩個(gè)液壓缸，以便均衡由 兩制動(dòng)蹄產(chǎn)生的壓力。（如圖7.1所示）每個(gè)制動(dòng)蹄的表面都覆蓋有制動(dòng)襯墊，制動(dòng)襯墊（制動(dòng)蹄摩擦片）產(chǎn)生高的摩擦阻力. （每個(gè)制動(dòng)蹄的表面都覆蓋有產(chǎn)生高摩擦阻力的制動(dòng)蹄摩擦片）。圖7.1鼓式制動(dòng)器1一制動(dòng)器后蓋2制動(dòng)蹄3一制動(dòng)襯片4一彈簧5一液壓缸wheel cylinderbrake pedalmaster cylinder jmetering valve(g .proportioning valvedisc brake

60、 caliper圖7.2液壓制動(dòng)系統(tǒng)的主要組成部分piston ucaliper bolted to suspension圖7.31盤(pán)式制動(dòng)器,中的一個(gè)活塞與制動(dòng)踏板相聯(lián)，所以當(dāng)駕駛 動(dòng)輪缸，并使它們的活塞移動(dòng)。油液將活塞 并將制動(dòng)蹄擠向位于車(chē)輪內(nèi)的制動(dòng)鼓。我們液壓系統(tǒng)包含一個(gè)制動(dòng)主缸和多個(gè)位于車(chē)輪上的制動(dòng)輪缸。制動(dòng)輪缸通過(guò)管道與制動(dòng)主 缸相連，并且整個(gè)系統(tǒng)都充滿(mǎn)液壓油。制動(dòng) 員踩下制動(dòng)踏板時(shí)，迫使油液向外流到每一個(gè) 推出液壓缸，接著，活塞又推動(dòng)制動(dòng)蹄的內(nèi)端說(shuō)這時(shí)制動(dòng)產(chǎn)生（起作用）。制動(dòng)蹄對(duì)固聯(lián)于車(chē)輪的制動(dòng)鼓產(chǎn)生的摩擦力，使汽車(chē)減速或停 止。當(dāng)允許制動(dòng)踏板抬起時(shí)，液壓油返回原處，活塞縮回，安裝