汽车专业英语(幻灯片)chapter 4 braking system.ppt

seaspecial english for automobile chapter 4 braking system and body construction energy is required when a vehicle is accelerated from rest to a certain speed. a proportion of that energy is now stored in the vehicle and is called kinetic energy. in order to reduce the speed of the vehicle, the brakes have to convert the kinetic energy to heat energy; the speed of conversion governs the rate at which the vehicle slows down. 汽车从原地起步加速到某一速度需要能量。储存在汽 车中的那部分能量称为动能。要降低车速,制动器必须 把汽车的动能转换为热能；转换的速度决定了汽车减 速的快慢。 review 1: whats the main function of braking system? seaspecial english for automobile chapter 4 braking system and body construction 1.disc brake 2.brake caliper 3.brake hose 4. brake pedal 1.disc brake 2.brake caliper 3.brake hose 4. brake pedal 5.master cylinder 6.wheel cylinder 7. drum brake5.master cylinder 6.wheel cylinder 7. drum brake review 2: list the main parts of braking system. seaspecial english for automobile chapter 4 braking system and body construction review 2: list the main parts of braking system. 1、energy-supplying device 供能装置 2、control device 控制装置 3、transmission device 传能装置 4、brake 制动器 seaspecial english for automobile chapter 4 braking system and body construction metering valve 节压阀 proportioning valve 比例阀 check valve 单向阀 solenoid valve 电磁阀 combination valve 组合阀 delay valve 延迟阀 modulator valve 调节阀 seaspecial english for automobile chapter 4 braking system and body construction according to function according to the types of energy used review 3: which types do the braking system have? service braking system parking braking system additional retarding braking system secondary (emergency )braking system muscular energy braking system (non-power braking system) energy assisted braking system (power assisted braking system) non-muscular energy braking system (power braking system) inertial braking system gravity braking system seaspecial english for automobile chapter 4 braking system and body construction the three types of braking systems are in use today: service braking system, parking braking system and additional retarding-braking system. the service braking system and the parking braking system have separate control and transmission devices. the service braking system is normally foot-operated, while the parking braking system is hand-operated. 目前使用的制动系统有三种类型：行车制动系，住车制动系 和辅助制动系行车制动系和住车制动系有独立的控制和传 动装置行车制动系通常使用脚刹，而驻车制动系通常使用 手刹 seaspecial english for automobile chapter 4 braking system and body construction according to energy transmission according to circuit review 3: which types do the braking system have? single-circuit braking system multi-circuit braking system mechanical braking system hydraulic braking system pneumatic braking system electromagnetic braking system combination braking system seaspecial english for automobile chapter 4 braking system and body construction two types of brakes are used in modern cars: drum brakes and disc brakes. since 1976, all cars have used disc brakes on the front wheels. most cars use drum brakes on the rear 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. 目前使用的制动器有两种类型：鼓式制动器和盘式制动器 从1976年开始，所有的汽车前轮都使用盘式制动器, 大部分 汽车后轮使用的是鼓式制动器. 在盘式制动器和鼓式制动器中 都使用液压系统. 液压系统把制动踏板与每个车轮的制动部件 相连接. review : types of the brake seaspecial english for automobile chapter 4 braking system and body construction drum brake 鼓式制动器 disc brake盘式制动器 wheel cylinder brake cam actuated brake wedge actuated brake disc brake with fixed caliper disc brake with floating caliper review : types of the brake seaspecial english for automobile chapter 4 braking system and body construction 制动主缸 制动轮缸 制动鼓 支承销 master cylinder wheel cylinder brake shoe and lining 制动蹄和制动衬片 brake drum anchor pin return spring brake shoe and lining brake drum seaspecial english for automobile chapter 4 braking system and body construction these have two shoes, anchored to a stationary back-plate, which are internally expanded to contact the drum by hydraulic cylinders or a mechanical linkage. 这种制动器有两个固定在制动底板上的制动蹄，通 过液压轮缸或机械杆系作用从内侧向外推开与制动 鼓接触。 review : operation process of drum brake seaspecial english for automobile chapter 4 braking system and body construction review : operation process of drum brake seaspecial english for automobile chapter 4 braking system and body construction review : whats main types of drum brakes . simplex drum brake (leading trailing shoe brake ) 领从蹄式制动器 duo-trailing shoe brake (two trailing shoe brake) 双从蹄式制动器 double leading shoe brake 单向双领蹄 duo-duplex drum brake（ dou two leading shoe brake ） 双向双领蹄式制动器 uni-servo drum brake 单向自增力式制动器 duo-servo drum brake 双向自增力式制动器 simplex drum brake 领从蹄式制动器 trailing shoe leading shoe seaspecial english for automobile chapter 4 braking system and body construction in the case of the simplex brake, c*(brake factor) is the sum of the values for the individual shoes, and is 2.0（ referred to a specific coefficient of friction)a disadvantage of this design is the great difference in the braking effect between the two brake shoes, and the resulting greatly increased wear on the leading shoe. for this reason, the trailing shoe is often equipped with a much thinner lining than the leading shoe. 就领从蹄而言， c*表示各蹄的值的总数，且.(特 指某一摩擦系数）这种设计的缺点是两个制动蹄制 动效果有很大不同，结果大大增加了领蹄上的摩擦 因此，从蹄的摩擦衬片比领蹄薄 seaspecial english for automobile chapter 4 braking system and body construction + plus 加号；正号 - minus 减号；负负号 plus or minus 正负负号 is multiplied by 乘号 is divided by 除号 is equal to 等于号 is not equal to 不等于号 is equivalent to 全等于号 is equal to or approximately equal to 等于或约约等于号 is approximately equal to 约约等于号 is less than 小于号 is more than 大于号 is not less than 不小于号 is not more than 不大于号 is less than or equal to 小于或等于号 is more than or equal to 大于或等于号 % per cent 百分之 英文标点符号翻译 seaspecial english for automobile chapter 4 braking system and body construction . full stop 句号 , comma 逗号 : colon 冒号 ; semicolon 分号 ? question mark 问号 ! exclamation mark (英式英语) exclamation point (美式英语) apostrophe 撇号 - hyphen 连字号 - dash 破折号 . dots/ ellipsis 省略号 “ single quotation marks 单引号 “ double quotation marks 双引号 parallel 双线号 division 分节号 arrow 箭号；参见号 seaspecial english for automobile chapter 4 braking system and body construction celsius system 摄氏度 open brace, open curly 左花括号 close brace, close curly 右花括号 ( open parenthesis, open paren 左圆括号 ) close parenthesis, close paren 右圆括号 () brakets/ parentheses 括号 open bracket 左方括号 close bracket 右方括号 square brackets 方括号 . period, dot 句号，点 | vertical bar, vertical virgule 竖线 because 因为 hence 所以 equals, as (proportion) 等于，成比例 angle 角 semicircle 半圆 circle 圆 circumference 圆周 pi 圆周率 triangle 三角形 perpendicular to 垂直于 union of 并，合集 intersection of 交，通集 the integral of 的积分 (sigma) summation of 总和 degree 度 minute 分 second 秒 dou-duplex drum brake seaspecial english for automobile chapter 4 braking system and body construction an advantage of this type of brake is the nearly equal brake lining wear on both shoes and the higher internal transmission ratio in comparison to simplex brakes. with two leading shoes, brake factors of c3.0 are achieved, however, these figures cannot be held constant throughout a long period of braking due to the susceptibility to fading of this type of brake. 这种制动器的优点是两个蹄上制动衬片磨损几乎相同 ，与领从蹄制动器相比它的内传动比较高使用两个 领蹄，制动因素可以达到3.0，但是由于这类制动器制 动性能易于衰退而使这个值不能在长距离制动时保持 恒定 duo-servo drum brake seaspecial english for automobile chapter 4 braking system and body construction this type of drum brake has an application mechanism which is simpler, more reliable and insensitive to temperature. it comprises diaphragm cylinder, automatic slack adjuster, brake shaft and s- cam. 这类凸轮制动器有一套简单，稳定，恒温机构它包 括膜片弹簧制动器室，自动调整臂，制动轴和s凸轮. 制动钳体 caliper 活 塞 piston 制动块 friction pad 制动盘 disc disc brake with fixed caliper disc brake with floating caliper seaspecial english for automobile chapter 4 braking system and body construction exposed to the air, disc brakes radiate the heat to the air better than drum brakes: this means that the brake can be operated continuously for a longer period, i.e. they have a greater resistance to fade (fall-off in brake efficiency due to heat). 由于暴露于空气中，盘式制动器的散热效果比鼓式的要好 ：这意味着盘式制动器能持续使用更长的时间，也就是说 其抗热衰退性（因受热导致制动效能下降）要好得多。 seaspecial english for automobile chapter 4 braking system and body construction disc brakes as used in most passenger cars are slowly beginning to be used in commercial vehicles as well. aside from their use in fast coaches, current use of disc brakes in commercial vehicles is primarily limited to front-axle brakes for commercial vehicles up to a weight of approx. 7.5 t which are driven in a manner similar to passenger cars. 常用在许多乘用车上的盘式制动器正逐渐被用于商用车. 它们 除用于快速客车外, 目前盘式制动器在商用车上的用途基本限 制在前轴制动, 因为商用车重量约等于7.5吨时驱动方式与乘 用车相似. seaspecial english for automobile chapter 4 braking system and body construction an advantage of disc brakes in comparison to drum brakes: better gradual braking efficiency equal wear of the inboard and outboard brake pads brake noise is better suppressed relatively constant brake factor performance with lower susceptibility to fading disadvantage ： short brake pad life when used on heavy-duty commercial vehicles higher acquisition and operating costs seaspecial english for automobile chapter 4 braking system and body construction the master cylinder contains two separate sections, there is a piston in each section and both pistons are connected to a brake pedal in the drivers compartment. 制动主缸由两个分开的部分组成，每个部分都有 一个活塞，两个活塞都与驾驶室里的制动踏板相 连接。 review : operation process of non-power brakes when the brake pedal is pushed by the driver, the two pistons move in the two sections of the master cylinder. this forces brake fluid out and through the brake lines, or tubes, to the brake mechanisms at the wheels. in a typical system, the brake fluid from one section of the master cylinder goes to the two front- wheel brakes. the brake fluid from the other section goes to the two rear-wheel brakes. the purpose of this that, if one section fails, the other section will still provide braking. 当驾驶员踩下制动踏板时，主缸两套管路中的两活塞移动迫 使制动液流出经过制动管路进入各车轮的制动装置中在标准 制动系统中，主缸的一条管路中的制动液流向两个前轮制动装 置中，另一条管路的制动液流向两个后轮制动装置其目的是 ，如果其中一套管路失灵，另一条管路仍然能够提供制动 制动踏板 brake pedal 真空助力器 vacuum booster 储液室 brake-fluid reservoir 盘式制动器 disk brake 制动主缸 master cylinder 比例阀 proportioning valve 真空管 vacuum connection 鼓式制动器 drum brake power-assisted brakes seaspecial english for automobile chapter 4 braking system and body construction the operating principle of the power-assisted system is the same as for a non-power system. however, braking force is increased through the use of a vacuum booster unit. atmospheric pressure helps to push the brake pedal. thus, less muscle effort is required. 伺服制动系的工作原理与人力制动系相同。然而，伺 服制动系通过采用真空助力装置来增加制动力。大气 压力有助于踩下制动踏板。这样，制动时几乎不需要 人力。 seaspecial english for automobile chapter 4 braking system and body construction in si engines, vacuum is generated via a connection to the engine intake manifold, and diesel engines use a vacuum pump. 火花点火式发动机通过连接发动机的进气支管产生真空，而 柴油发动机使用真空泵 the vacuum booster is a pedal-force booster which is combined with a tandem master cylinder. the boost factor i can be varied in design by an appropriate choice of lever control. via the lever control, a proportional assisting force is superimposed on the pedal force, and both act together on the tandem master cylinder. at the same time, a reactive force is conveyed to the driver, which enables him to meter the braking action correctly. 真空助力器是一个与制动主缸串联在一起的踏板助力器设计 时助力因数i可通过选择适当的杠杆控制而不同通过杠杆控制 ，一定比例的助力叠加在踏板力上并同时对串联式制动主缸作 用同时，反作用力传给驾驶员，使他能正确的估计制动行为 tandem master cylinder 储液室 fluid reservoir 补偿孔 snifter hole rear brake front brake 中间活塞 intermediate piston 机架 housing 推杆 push-rod seaspecial english for automobile chapter 4 braking system and body construction operation principle (tandem master cylinder): after passing over snifter hole, the push-rod piston forces the brake fluid into brake circuit . the compression of the spring and the pressure buildup in brake circuit i actuates the intermediate piston, which passes over snifter hole and builds up pressure in brake circuit . 工作原理(串联式制动主缸）：推杆活塞经过补偿孔迫使制动 液流入制动回路弹簧压缩力及制动回路上的压力促动中 间活塞，使它经过补偿孔并在制动回路上产生压力 seaspecial english for automobile chapter 4 braking system and body construction the port for brake circuit i, which supplies the rear drum brakes, has a pre-pressure valve which assures a residual pressure of approx 150kpa when the brakes are released. this prevents the entry of air through the wheel-cylinder seals. 制动回路i上的孔为后轮鼓式制动器提供制动液其内有 一个预压阀，它保证制动踏板释放时有150kpa残余压力, 阻止空气通过轮缸密封处进入 the more heavily the driver brakes, the greater is the dynamic shifting of weight from the rear axle to the front axle. with the vehicle empty, the braking force at the rear axle may be so great that the rear axle locks before the front axle. this can lead to instability when braking, i.e. to skidding .braking stability is obtained when, irrespective of vehicle loading, the front axle always locks before the rear axle. the correct braking-force distribution can be achieved by brakepressure-regulating valves which are installed in the brake lines to the wheels of the rear axle. 驾驶员制动力越大，从后轴到前轴的转移的重量越大汽车空载时，后轴上 制动力很大以至后轴在前轴之前抱死这导致制动不稳定，即发生滑动当 前轴总在后轴之前抱死时可获得制动稳定性，它与汽车载重无关通过安装 在连接后轮的制动管路上的制动压力调节装置可以得到正确的制动力分配 seaspecial english for automobile chapter 4 braking system and body construction during initial braking, the control spring keeps the valve seat at the stepped piston open until the brake pressure has reached a level which, according to the active area of the stepped piston, corresponds to the force of the control spring. 开始制动时，控制弹簧使阶梯型活塞上的阀门座打开，直到 制动压力按照阶梯形活塞有效面积达到与控制弹簧力相同的 程度 seaspecial english for automobile chapter 4 braking system and body construction review 7: which components do compressed air brakes have? 1、energy-supplying device 供能装置 2、control device 控制装置 3、executive device 执行装置 1 compressor 空气压缩机 2 brake cylinder 制动气室 3 brake valve 制动阀 4 water-drain valve 放水阀 5 air reservoir 湿储气罐 6 master reservoir 主储气罐 7 pressure regulator 调压阀 8 barometer 气压表 9 bugle 喇叭 seaspecial english for automobile chapter 4 braking system and body construction a compressor is used as the energy source, and is usually of the plunger type; the intake air is compressed via automatic suction and delivery valves. 空压机用做能源一般是活塞型的通过自动进气阀进入 的空气在其内被压缩 service brake valve seaspecial english for automobile chapter 4 braking system and body construction the combination brake cylinder consists of a single- chamber diaphragm cylinder for the service brakes and a spring-brake actuator for the parking brakes. the cylinder and spring brake actuator are in tandem and act on a common pressure rod. 复合式制动室由行车制动器的单室膜片弹簧制动气室和驻车 制动器弹簧助力装置组成制动气室和弹簧助力装置串联在 一起并对压力杆作用 electrohydraulic braking systems are designed to allow electonic control of vehicle braking while retaining a reduced hydraulic system. the ehb control unit receives inputs from sensors connected to the brake pedal. in normal operation, a backup valve is closed and the controller activates the brakes of the wheel through an electric motor driven hydraulic pump. when the controller goes into a fail-safe mode, the backup valve is opened, which allows the brakes to be controlled through a conventional hydraulic circuit. 电液制动系统允许电子控制汽车制动,同时保留了简化的液压系 统.电液制动系统控制单元接受与制动踏板连接的传感器的输入. 正常工作时, 后备阀关闭, 控制器通过由液压泵驱动的电动机起 动制动器. 当控制器进入失效安全模式时,后备阀打开, 并允许传 统的液压回路控制制动器. seaspecial english for automobile chapter 4 braking system and body construction additional retarder brake system 辅助制动系 a. exhaust retarder 排气缓速器 b. hydrodynamic retarder 液力缓速器 c. electromagnetic retarder 电磁缓速器 d. traction motor retarder 牵引电机缓速器 e. aerodynamic retarder 空气动力缓速器 seaspecial english for automobile chapter 4 braking system and body construction in order to brake the vehicle, the field coils are supplied with current (from the battery or alternator) and generate a magnetic field. eddy currents are induced in the rotors as they pass through this field. this generates a braking torque whose magnitude is a function of the excitation of the stator coils. 为了刹车，用电池或发电机给励磁线圈供电从而产生磁场 当转子经过磁场时感应生成电涡流这样产生的制动力 矩的大小是定子线圈中励磁电流的函数 seaspecial english for automobile chapter 4 braking system and body construction brake slip = (f r)/ f 100% 滑动率 ； 100 bbraking-force coefficient 制动力系数 slateral-force coefficient 侧向力系数 b s seaspecial english for automobile chapter 4 braking system and body construction main parts of abs （antilock braking system) 轮缸 电控 单元 电 动 机 液压泵 主缸 线圈 电磁阀 轮速传感器 wheel cylinder wheel-speed sensor electronic controller solenoid-valve coil motor hydraulic pump plunger seaspecial english for automobile chapter 4 braking system and body construction the wheel-speed sensor monitors