毕业设计--汽车防抱死系统相关文献翻译

防抱死制动系统 防抱死制动系统 ABS 全称是 Anti-lock Braking System，即 ABS，可安装在任何带液压刹车的汽车上。它是利用阀体内的一个橡胶气囊，在踩下刹车时，给予刹车油压力，充斥到 ABS 的阀体中，此时气囊利用中间的空气隔层将压力返回，使车轮避过锁死点。 简介 ABS（ Anti-lock Braking System）防抱死制动系统，通过安装在车轮上的传感器发出车轮将被抱死的信号，控制器指令调节器降低该车轮制动缸的油压，减小制动力矩，经一定时间后，再恢复原有的油压，不断的这样循环（每秒可达 5-10 次 ），始终使车轮处于转动状态而又有最大的制动力矩。 没有安装 ABS 的汽车，在行驶中如果用力踩下制动踏板，车轮转速会急速降低，当制动力超过车轮与地面的摩擦力时，车轮就会被抱死，完全抱死的车轮会使轮胎与地面的摩擦力下降，如果前轮被抱死，驾驶员就无法控制车辆的行驶 方向，如果后轮被抱死，就极容易出现侧滑现象。 提示：在遇到紧急情况时，制动踏板一定要踩到底，才能激活 ABS 系统，这时制动踏板会有一些抖动，有时还会有一些声音，但也不能松开，这表明 ABS系统开始起作用了。 分类 一是按生产厂家分类，二是按控制通道分类。以下主要介绍按通道分类的方法。在 ABS 中，对能够独立进行制动压力调节的制动管路称为控制通道。 ABS 装置的控制通道分为四通道式、三通道式、二通道式和一通道式。 (1)四通道式 四通道 ABS 有四个轮速传感器，在通往四个车轮制动分泵的管路中，各设一个制动压力调节器装 置，进行独立控制，构成四通道控制形式。但是如果汽车左右两个车轮的附着系数相差较大 (如路面部分积水或结冰 )， 制动时两个车轮的地面制动力就相差较大，因此会产生横摆力矩，使车身向制动力较大的一侧跑偏，不能保持汽车按预定方向行驶，会影响汽车的制动方向稳定性。因此，驾驶员在部分结冰或积水等湿滑的路面行车时，应降低车速，不可盲目迷信 ABS 装置。 (2)三通道式 三通道 ABS 是对两前轮进行独立控制，两后轮按低选原则进行一同控制 (即两个车轮由一个通道控制，以保证附着力较小的车轮不抱死为原则 )，也称混合控制。桑塔纳 2000GSi 既是用的这种 ABS 装置。 性能特点：两后轮按低选原则进行一同控制时，可以保证汽车在各种条件下左右两后轮的制动力相等，即使两侧车轮的 附着系数相差较大，两个车轮的制动力都限制在附着力较小的水平，使两个后轮的制动力始终保持平衡，保证汽车在各种条件下制动时都具有良好的方向稳定性。在对桑塔纳 2000 进行的 60 km/h 紧急制动对比试验中，有 ABS 的车型比无 ABS 车型的制动距离只短 1 米，但是有ABS 的车型始终都有方向，不会失去对方向的控制。 对两前轮进行独立控制，主要考虑小轿车，特别是前轮驱动的汽车，前轮的制动 力在汽车总制动中所占的比例较大 (可 达 70%左右 )，可以充分利用两前轮的附着力。但由于两前轮制动力不平衡对汽车行驶方向稳定性影响相对较小，而且可以通过 驾驶员的转向操纵对由此产生的影响进行修正。因此，三通道 ABS在小轿车上被普遍采用。 (3)二通道式 二通道式 ABS 难以在方向稳定性、转向控制性和制动效能各方面得到兼顾，目前采用很少。 (4)一通道式 一通道式 ABS 常叫单通道 ABS，它是在后轮制动器总管中设置一个制动压力调节器，在后桥主减速器上安装一个轮速传感器 (也有在后轮上各安装一个 )。 性能特点 单通道 ABS 一般都是对两后轮按低选原则进行一同控制。单通道 ABS 不能使两后轮的附着力得到充分利 用，因此制动距离不一定会明显缩短。另外前轮制动未进行控制，制动时前轮仍会出现制动抱死，因而转向操纵能力也未得到改善，但由于制动时两后轮不会抱死，能够显著的提高制动时的方向稳定性，在安全上是一大优点，同时结构简单，成本低等优点，所以在轻型载货车上广泛应用。 综上所述， ABS 装置虽然具有缩短制动距离、另外，不同类型的 ABS 装置由于组成结构等原因，价格也相差较大，所 以选购汽车时不能只看到价格高低，还应看到装用的是那种类型的 ABS 装置。 优点 当车轮即将到达下一个锁死点时，刹车油的压力使得气囊重复作用，如此在一秒钟内可作用 60120 次，相当于不停地刹车、放松，即相似于机械的 “ 点刹 。因此， ABS 防抱死系统，能避免在紧急刹车时方向失控及车轮侧滑，使车轮在刹车时不被锁死，不让轮胎在一个点上与地面摩擦，从而加大摩擦力，使刹车效率达到 90%以上，同时还能减少刹车消耗，延长刹车轮鼓、碟片和轮胎两倍的使用寿命。装有 ABS 的车辆在干柏油路、雨天、雪天等路面防滑性能分别达到80% 90%、 10% 30%、 15% 20%。 局限性 ABS 系统本 身也有局限性，它仍然摆脱不了一定的物理规律。在两种情况下，ABS 系统不能提供最短的制动距离。一种是在平滑的干路上，由有经验的驾驶员直接进行制动。另一种情况是在松散的砾石路面、松土路面或积雪很深的路面上制动 另外，通常在干路面上，最新的 ABS 系统能将滑移率控制在 5% 20%的范围内，但并不是所有的 ABS 都以相同的速率或相同的程度来进行制动。尽管四轮防抱制动系统能使汽车在尽可能短的距离内进行制动，但如果制动进行得太迟，使之在与障碍物碰撞前不能完全停下来，仍不能阻止事故的发生。 工作原理 制动总泵 制动踏板 电动机 储液罐 ABS 控制单元 制动分泵 轮速传感器 车轮 在制动时， ABS 根据每个车轮速度传感器传来的速度信号，可迅速判断出车轮的抱死状态，关闭开始抱死车轮上面的常开输入电磁阀，让制动力不变，如果车轮继续抱死，则打开常闭输出电磁阀，这个车轮上的制动压力由于出现直通制动液贮油箱的管路而迅速下移，防止了因制动力过大而将车轮完全抱死。在让制动状态始终处于最佳 点（滑移率 S 为 20%），制动效果达到最好，行车最安全。 防抱死制动系统 在制动总泵前面腔内的制动液是动态压力制动液，它推动反应套筒向右移动，反应套筒又推动助力活塞从而使制动踏板推杆向右移。因此，在 ABS 工作地时候，驾驶员可以感觉到脚上踏板地颤动，听到一些 噪音。 汽车减速后，一旦 ABS 电脑检测到车轮抱死状态消失，它就会让主控制阀关闭，从而使系统转入普通的制动状态下进行工作。如果蓄压器的压力下降到安全极限以下，红色制动故障指示灯和琥珀色 ABS 故障指示灯亮。在这种情况下，驾驶员要用较大的力进行深踩踏板式的制动方式才能对前后轮进行有效的制动。 工作过程 在 ABS 中，每个车轮上各安置一个转速传感器，将关于各车轮转速的信号输入电子控制装置。电子控制装置根据各车轮转传感器输入的信号对各个车轮的运动状态进行监测和判定并形成相应的控制指令。各处液压电磁阀均不通电而处于关闭状 态，电动泵也不通电运转，制动主缸至各制动轮缸的制动管路均处于沟通状态，而各制动轮缸至储液器的制动管路均处于封闭状态，各制动轮缸的制动压力将随制动主缸的输出压力而变化，此时的制动过程与常规制动系统的制动过程完全相同。 在制动过程中，电子控制装置根据车轮转速传感器输入的车轮转速信号判定有车轮趋于抱死时， ABS 就进入防抱死制动压力调节过程。例如，电子控制装置判定右前轮趋于抱死时，电子控制装置就使控制右前轮制动压力的进液电磁阀通电，使右前进液电磁阀转入关闭状态，制动主缸输出的制动液不再进入右前制动轮缸，电子控制装置 就使右前进液电磁阀和出液电磁阀都断电，使进液电磁阀转入开启状态，使出液电磁阀转入关闭状态，同时也使电动泵通电运转，向制动轮缸送制动液，由制动主缸输出的制动液和电动泵泵送的制动液都经过处于开启状态的右前进液电磁阀进入右前制动轮缸，使右前制动轮缸的制动压力迅速增大，右前轮又开始减速转动。 ABS 通过使趋于抱死车轮的制动压力循环往复地经历保持 减小 增大过程，而将趋于抱死车轮的滑动率控制在峰值附着系数滑动率的附近范围内，在该ABS 中对应于每一个制动轮缸各有一对进液和出液电磁阀，可由电子控制装置分别进行控制，因此， 各制动轮缸的制动压力能够被独立地调节，从而使四个车轮都不发生制动抱死现象。 尽管各种 ABS 的结构形式和工作过程并不完全相同，但都是通过对趋于抱死车轮的制动压力进行自适应循环调节，来防止被控制车轮发生制动抱死的，而且，各种 ABS 在以下几个方面都是相同的。 （ 1） ABS 只是汽车的速度超过一定以后（如 5km/h 或 8km/h），才会对制动过程中趋于抱死的车轮进行防抱死制动压力调节。当汽车速度被制动降低到一定时， ABS 就会自动中止防抱死制动压力调节，此后，装备 ABS 汽车的制动过程将与常规制动系统的制动过程相同，车轮 被制动抱死对汽车制动抱死。这是因为在汽车的速度很低时，车轮被制动抱死对汽车制动性能的影响已经很小，而且要使汽车尽快制动停车，应必须使车轮制动抱死。 （ 2） 在制动过程中，只有当被控制车轮趋于抱死时， ABS 才会对趋于抱死车轮的制动压力进行防抱死调节；在被控制车轮还没有趋于抱死时，制动过程与常规制动系统的制动过程完全相同。 （ 3） ABS 都具有自诊断功能，能够对系统的工作情况进行监测，一旦发现存在影响系统正常工作的故障时将自动地关闭 ABS，并将 ABS 警示灯点亮，向驾驶员发出警示信号，汽车的制动系统仍然可以像常规 制动系统一样进行制动。 故障检修 ABS 检修注意事项 ABS 与普通制动系统是不可分的，普通制动系统一旦出现问题， ABS 就不能正常工作，因此，要将二者视为整体进行维修。 ABS 电控单元对过电压、静电非常敏感，如有不慎就会损坏电控单元中的芯片，造成 ABS 失效。因此，点火精工关接通过时不要插或拔电控单元上的连接器；在车上进行电焊之前，要戴好防静电器（也可用导线一头缠在车体上），拔下电单元上的连接器后再进行电焊；给蓄电池进行专门充电时，要将蓄电池从车上拆下蓄电池电缆后再进行充电。 维修转带传感器时要十分 小心，拆卸时注意不要碰伤传感器头，不要将传感器齿圈当撬面，以免损坏。安装时应先涂覆防锈油，安装过程中不可调敲击或作蛮力。一般情况下，传感器气隙是可调的（也有不可调的），调整时应用无磁性塞尺（如塑料或铜塞尺），当然也可以用纸片。 维修 ABS 液压控制装置时，切记要先泄压，再按规定进行修理，以免高压油喷出伤人。 制动液至少每隔两年更换一次，最好是每年更换一次。这是因为 DOT3 乙二醇制动液的吸湿性很强，含水分的制动液不仅使制动系统内部产生腐蚀，而且会使制动效果明显下降，影响 ABS 的正常工作。注意不要使用 DOT5 硅酮制动液，更换和存储的制动液及器皿要清洁，不要让污物、灰尘进入液压系统。制动液不要沾到 ABS 电控单元和导线上。最后，要按规定的方式进行放气（与普通制动系统的放气有所不同）。 在进行 ABS 诊断与检查时，只要掌握检测仪器等专用工作的使用方法，按照维修手册中给的故障诊断图表诊断即可，可不拘泥于检查形式和步骤，目的是准确判断故障点。更换 ABS 零部件时，一定要选用该车型高质量正品配件，以确保ABS 维修后能正常工作。 ABS 故障类别及处理方法 ABS 故障基本上可分为电路故障、机械故障及外来干扰等三大类。 电路 故障。接通电源， ABS 指示灯应亮，而一旦车速达到 10km/h 时，指示灯应自动熄灭，否则说明 ABS 有故障。 ABS 压力调节器均使用电磁阀，电压过高可能使其烧坏，电压过低使其不能正常工作。一般电源电压不可超过电磁阀额定电压的 15% ，对电控单元也存在上述同样的问题，否则 ABS 会误动作。 脉冲环。脉冲环为一个铁质齿圈，起改变传感器磁场的作用。它固定在轮毂上，不与任何零部件接触。对此，有人不了解，误以为脉冲起齿轮的传动作用，而给其加润滑油或润滑剂，这样铁屑等杂物在其上积存，杂质积存过多，必然破坏传感器的灵敏度。 脉冲 环与轮毂不同轴，传感器与脉冲环的间隙是变化的，会影响其车轮运动的测试精度。造成这种情况的原因大致有安装脉冲环方法不当，脉冲环变形（保修车辆时对脉冲环造成不必要的冲击）、车轮轴承磨损松动等。脉冲环破损，也会影响测试四轮运动状态参数的准确性。 遇上述情况，需要换脉冲环时，应重新确定传感器与脉冲环问题（ 0.20.5mm）。 压力调节器， ABS 电路良好，传感器能准确测量车轮运动状态。而 ABS 性能不良，如制动距离增长、防抱死抽动作用失控等，则为压力调节器故障所致。压力调节器的轻微故障是响应迟缓、增益不当，严重故障是 工作不受 ABS 控制，脱开 ABS 不能恢复到常用的制动功能。 Anti-lock braking system ABS anti-lock Braking System full name is Anti - lock style System, namely the ABS, can be installed in any car with hydraulic brake.It is to use the body of a rubber balloon, when put on the brakes, brake oil pressure, fill in the body of ABS, airbag use at this time in the middle of the air interlayer pressure back, evaded the wheel lock. Introduction to the ABS (Anti - lock style System), anti-lock Braking System, by mounted on the wheel sensor signal that the wheels will be lock, the controller command the oil pressure regulator to reduce the wheel brake cylinder, decrease the Braking moment, after a certain period of time, to restore the original hydraulic, constantly such cycles per second (up to 5-10 times), always in a state of rotation and the wheel has the largest Braking torque. Not installed ABS car, on the road if hard on the brake pedal, the wheel speed will decline dramatically, when braking more than wheel friction with the ground, the wheels will be lock, lock the wheels will be completely bring down the tire friction with the ground, if the front wheel lock, the driver could not control the vehicles driving direction, if the rear wheel lock, is extremely easy to appear sideslip phenomenon. Note: in case of emergency, the brake pedal must step on to the end, to activate the ABS system, the brake pedal will have some jitter, sometimes there will be some sound, but also cant loosen, this shows that the ABS system began to work. Classification It is classified by the manufacturer, 2 are classified according to the control channel.The following mainly introduces the method of classification according to the passage.In the ABS brake pressure regulation of independently brake line known as the control channel. ABS device of control channel is divided into four leading, three single, two leading and one single. (1) the four leading Four-channel ABS has four wheel speed sensor, on the line to four wheel brake cylinder, each set a braking pressure regulator device, an independent control, constitute a four-channel control form.But if the car around the two wheels of the adhesion coefficient is large (e.g., road surface water or ice), brake when the two wheels of the ground braking force is comparatively large difference, so will produce yawing moment, make the body to the braking force is bigger on one side of the wandering, cant keep the car was going at predetermined direction, will affect the automobile braking direction stability.Therefore, the driver in the partial freezing, or water wet road driving, should reduce the speed of the car, not blindly superstition ABS device. (2) the three leading three-channel ABS is an independent control of two front wheels, two rear wheels according to the principle of low choose together control (namely the two wheels is controlled by a channel, to ensure adhesion of the smaller wheels do not lock for the principle), also called hybrid control.Santana 2000 gsi is with the ABS device. Principle of performance characteristics: choose two rear wheels according to the low control together, can ensure the vehicle under various conditions around two rear wheel braking force is equal, even if the wheels on both sides of adhesion coefficient is large, and the two wheels of braking adhesion limit in smaller level, make the two rear wheel braking force balance all the time, ensure the vehicle under various conditions with good directional stability when braking.60 km/h on santana 2000 emergency braking contrast experiment, without ABS models have ABS models than short braking distance is only 1 meter, but there are ABS models always have a direction, not lose control of the direction. an independent control of two front wheels, main consideration car, especially the front wheel drive car, the front wheel braking force in car brake and the proportion of the total large (up to 70%), can make full use of the two front wheel adhesion.But because the two front wheel braking force balance effect on the stability of the car moving direction is relatively small, and can pass the drivers steering affects the resulting correction.Therefore, three-channel ABS is extensively used in cars. (3) the two leading Two leading ABS in directional stability, steering control and braking performance in all aspects to get to two or morethings, currently USES very little. (4) a single a single ABS is often called the single channel ABS, it is in the rear wheel brake main set a braking pressure regulator, the rear axle main reducer is installed on a wheel speed sensor (or on the rear wheels to install a). The performance characteristics of Single channel ABS are generally of low two rear wheels according to the principle of choose control together.Single channel ABS can not make full use of the two rear wheels adhesion, so braking distance is not necessarily will be significantly reduced.Additionally the front wheel braking control, brake, brake, holding in death of the front wheel will appear when the ability of steering did not improve, but since the two rear wheels wont lock when braking, can significantly improve the direction stability when braking, on safety is a big advantage, at the same time, simple structure, low cost advantages, so widely used in light truck. To sum up, although ABS device has shorten braking distance, in addition, different types of ABS plant due to reasons such as the structure, the price also differs, to choose and buy cars can not only see the price, but should also see with that type of ABS device. advantages Locking when the wheel is about to reach the next point, brake oil pressure makes the airbag repeated role, so in a second role 60 120 times, equivalent to constantly braking, relaxation, that is, similar to mechanical DianCha . Therefore, ABS anti-lock braking system, to avoid direction out of control and wheel sideslip when emergency braking, the wheel when the brakes are not locked, dont let the tire friction with the ground at one point, so as to increase the friction, the brake efficiency of 90% or more, at the same time also can reduce the brake consumption, prolong brake wheel drum and disc and the service life of tires twice. Vehicles equipped with ABS on dry asphalt, rain, snow and other pavement skid resistance were 80%, 90%, 10%, 90%, 15%, 20%. limitations ABS system itself also has limitations, it still cant get away from a certain physical laws.In both cases, ABS system cant provide the shortest braking distance.One is in the way of smooth, dry, directly by the experienced drivers to brake.Another case is in the loose gravel road surface, road surface dirt or snow deep road braking In addition, usually in one plane, the latest ABS system can slip rate control in the range of 5% 20%, but not all at the same rate of ABS braking or the same level.Although four-wheel braking system can make the car to prevention brake carried out within the shortest possible distance, but if the brake is going too late, so cant completely stop before collisions with obstacles, are still unable to prevent the accident. The working principle of Brake master cylinder The brake pedal motor Storage tank The ABS control unit Brake wheel cylinder Wheel speed sensor The wheels When braking, ABS, according to the speed of each wheel speed sensor transmits signals can rapidly determine the wheel lock state, close to lock the wheels of the above input solenoid valve normally open, let the braking force is constant, if the wheel to lock and open a normally closed output electromagnetic valve, the wheel brake pressure due to the brake fluid storage tank of the pipeline and quickly down, to prevent the wheel braking force is too large and will simply be lock.To remain the best braking state point (slip rate S of 20%), braking effect is best, the most safe driving. Anti-lock braking system The brake fluid in front of the brake master cylinder cavity is dynamic pressure brake fluid, it promote the reaction sleeve to the right, the reaction sleeve and push the power piston so that the brake pedal putter move to the right.In ABS working time, therefore, the driver can feel foot pedal to vibrate, heard some noise. Car slow down after, once the ABS wheel lock computer detected state disappear, it will make the main control valve closed, so that the system into the ordinary work under braking condition.If the pressure of the accumulator dropped to below the safety limits, red brake failure indicator and amber ABS fault indicator light is lit.In this case, the driver should use greater force for deep step on the pedal braking ability to the front and back brake effectively. The working process of the In ABS, each wheel set a speed sensor, will be on each wheel speed signal input of the electronic control unit.Electronic control device according to each wheel turning sensor input signals for each wheel for monitoring and determine the motion state of and formation of the corresponding control command.Various hydraulic solenoid valves are closed without electricity, electric pump is not electricity, brake master cylinder to the brake line of each wheel cylinder are still in the state of communication, and the brake pipe of the brake wheel cylinder and accumulator are in a closed state, each wheel cylinder brake pressure will change along with the output pressure of brake master cylinder, brake process at this time with conventional braking system of the braking process is exactly the same. In the process of braking, the electronic control unit based on wheel speed sensor input wheel speed signal are ascertained wheel tends to lock, ABS anti-lock brake pressure regulation is entered into the process.Electronic control devices, for example, to determine when the right front wheel tends to lock, electronic control unit makes the control right front wheel brake pressure liquid into the solenoid valve electricity, electromagnetic valve to close the right front into liquid state, brake master cylinder output brake fluid is no longer into the right front wheel braking cylinder, the electronic control unit makes the right front into hydraulic solenoid valve and solenoid valve of produced liquid and electricity into hydraulic solenoid valve to open, use hydraulic solenoid valve to close state, also make electric power pump running at the same time, to send the brake fluid, brake wheel cylinder brake fluid output by a brake master cylinder and electric pump pumping the brake fluid are in an open position right front into hydraulic solenoid valve into the right front wheel cylinder, make the right front wheel cylinder brake pressure increased rapidly, right front wheel and began to slow. ABS by making tend to lock the wheel brake pressure cycling to keep increase with the decrease of - - process experience, and will tend to lock the wheel slip rate control near the adhesion coefficient of sliding rate range, corresponding to each in the ABS wheel cylinder has a pair of each into the fluid and the fluid electromagnetic valve, can be controlled by an electronic control device, respectively, as a result, each wheel cylinder brake pressure can be independently adjust, so that the four wheel brake lock phenomenon doesnt occur. Despite various ABS structure and work process is not exactly the same, but is based on tend to lock the wheel brake pressure for adaptive cycle adjustment, to prevent the control wheel brake lock, and a variety of ABS in the following aspects are the same. (1) after the car speed exceeds a certain ABS just (e.g., 5 km/h or 8 km/h), will tend to lock in the braking process of wheel anti-lock brake pressure regulation.Speed when the car is braking to reduce to a certain, ABS will automatically suspend the anti-lock brake pressure regulation, since then, equipped with ABS automotive braking process will be the same as the conventional braking of the braking system, wheel brake lock on the car brake lock.This is because the cars speed is very low, wheel brake lock is the impact on the automobile braking performance is very small, and see to it that car parking brake as soon as possible, should have to make the wheel brake lock. (2) in the braking process, only when the control wheel tends to lock, ABS to tend to lock the wheels to anti-lock brake pressure regulation；Not tend to lock in the controlled wheels, braking and braking process of conventional braking system is exactly the same. (3) the ABS has self-diagnosis function, able to work on the system of condition monitoring, once found the normal operation system failure will automatically shut down the ABS, and ABS warning light will light up, alert the driver signal, the automobile braking system can still like a conventional braking system for brake. troubleshootin