离合器汽车制动系统外文文献翻译@中英文翻译@外文翻译

外文资料译文 1 3.1 Clutc h The engine produces the power to drive the vehic le. The drive line or drive train transfers the power of the engine to the wheels. The drive train cons ists o f the parts fro m t he back of the flywhee l to the w heels. These parts include the clutch, the trans miss ion, the drive shaft, and the final drive assembly. The clutc h which inc ludes the flyw heel, clutc h disc, pressure plate, springs, pressure plate cover and the linkage necessary to operate the clutc h is a rotating mecha nism between the engine and the trans miss ion. It operates through fr ictio n whic h comes fro m contact between the parts. That is the reason why the c lutch is called a fr ict ion mecha nism. A fter engage ment, t he clutch must cont inue to transmit all e ngine torque to transmiss ion depe nd ing on the fr ict ion w itho ut slippage. The clutch is also used to disenga ge the engine from the drive train whene ver the gears in the transmission are being shifted from gear ratio to another. To start the engine or shift the gears, the driver has to depr ess the clutc h pedal w it h the purpose of d isenga geme nt the trans missio n fro m the engine. At that t ime, the driven me mbers connected to the transmiss ion inp ut shaft are eit her stationary or rotating at a speed that is slower of faster than the driving membe rs connected to engine cranksha ft. There is no spring pressure on the clutch asse mbly parts. S o there is no frict ion between the driving members and driven me mbers. As the driver lets loose the c lutc h pedal, spring pressure increase on the clutch parts. F rict ion between the parts also increases. The pressure exerted by the springs on t he drive n members is contro lled by the dr iver through the clutch pedal and linkage. The posit ive engage me nt of the driving a nd drive n members is made possib le the fr ict ion be tween the surfaces of the members. When full spring pressure is applied, the speed of the driving and driven me mbers should be the same. At the 外文资料译文 2 mo ment, the clutch must act as a coupling device and transmit a ll engine power to the transmission, without slip ping. However, the transmiss ion should be engaged to the engine gradually in order to operate the car smoothly and minimize tens iona l shock on the drive train because an engine at id le just develop litt le power. O therw ise, the driving me mbers are connecte d wit h the driven members too quickly and the engine would be stalled. The flyw heel is a major part of the clutch. The flyw heel mo unts to the engines crankshaft and trans mits engine torque to the clutch assemb ly. T he flyw heel, w hen coup led wit h the c lutc h disc and pressure plate makes and breaks the flow of power the engine to the transmission. The flywhee l provides a mount ing locat ion for the clutch assemb ly as well. When the clutch is applied, the flywhee l transfers engine torque to the clutch d isc. Because of its we ight, the flyw heel he lps to smooth engine operation. T he flyw heel a lso has a large r ing gear at its outer edge, which engages w ith a pinion gear on the starter motor during engine cranking. The clutc h disc fits between the flywhee l and the pressure plate. The clutch d isc has a splinted hub that fits over splints on the transmiss ion input sha ft. A splinted hub has grooves that match splints on the shaft. These splints fit in the grooves. Thus, the two parts held together. However, back and forth move ment of t he disc on the sha ft is possible. Attached to the input sha ft, the d isc turns at the speed of the shaft. The clutch pressure plate is generally made of cast iron. It is round and about the sa me dia meter as the clutch d isc. O ne side of t he pressure plate is machined smooth. This s ide will press the clutch d isc facing are against the flyw heel. T he outer s ide has shapes to facilitate attachment of spring a nd release mechanis m. T he two primary t ypes of pressure plate assemblies are coil spring assembly and diaphragm spring. 外文资料译文 3 In a coil spring c lutc h the pressure plate is backed by a number of coil springs and housed wit h them in a pressed steed cover bolted to the flyw hee l. The spring pushes against the cover. N eit her the driven plate nor the pressure plate is connected rigid ly to the flywhee l and both can move either towards it o away. When the clutch pedal is depressed a thrust pad riding on a carbon or ba ll thrust bearing is forced towards the flyw heel. Levers pivoted so that they engage wit h the thrust pad at one end and the pressure plate tat the other end pull the pressure plate back against its spr ings. This re leases pressure on the driven plate disconnecting the gearbox from the engine. Diaphragm spring pressure p late assemb lies are w idely used in most mod ern cars. The diaphragm spr ing is a single thin sheet of meta l which yie lds when pressure is applied to it. When pressure is remo ved the metal spring back to its origina l shape. The center portion of the diaphragm spring is s lit int o numerous fingers that act as release le vers. When the clutch assembly rotates wit h the engine these weights are flung outwards by centrifuga l p late and cause the levers to press against the pressure plate. Dur ing d isenga geme nt of t he c lutch the fingers a re moved forward by the release bearing. The spring pivots over the fulcrum r ing a nd its outer rim mo ves away fro m t he flyw heel. The retracting spring pulls the pressure plate away from the clutch plate thus disengaging the clutch. When enga ged the release bearing and t he fingers of t he diaphrag m spring move towards the transmiss ion. As the diaphragm p ivots over the pivot ring its outer rim forces the pressure plate against the clutch disc so that the clutch plate is engaged to flywheel. The advantages of a diaphragm t ype pressure plate assemb ly are its compactness, lower weight, fewer moving parts, less effort to enga ge, reduces rotationa l imbala nce by providing a bala nced force around the pressure plate and less chances of clutch slippage. The clutch peda l is connected to the disengage ment mecha nis m 外文资料译文 4 either by a cable or, more commonly, by a hydraulic syste m. E ither way, pushing the pedal down operates the dise nga geme nt mechanis m w hich puts pressure on the fingers of t he clutch diaphra gm via a release bearing and causes the diaphragm to release the clutch p late. With a hydraulic mechanis m, the clutch pedal arm operates a piston in the clutc h master cylinder. This forces hydraulic fluid through a pipe to the cutch release cylinder where another operates the c lutc h disenga ge ment mechanism by a cable. The other parts inc luding the clutch fork, release bearing, be ll hous ing, bell hous ing cover, and pilot bushing are needed to couple and uncoup le the trans missio n. The clutch fork, which connects to the linkage, actually operates the clutch. The release bearing fits between the clutch fork and the pressure plate assemb ly. T he bell ho using covers the clutch assemb ly. The bell hous ing cover fastens to the bottom of the bell hous ing. T his removab le cover allows a me chanic to inspect the clutc h wit hout remo ving the transmiss ion and bell ho us ing. A pilot bushing fits into the back of the crankshaft and ho lds the trans miss ion input shaft. 3.2 Brake System The breaking system is the most important system in cars. If the brakes fa il, the result can be disastrous. Brakes are actua lly energy conversion devices, whic h convert the kinet ic energy ( mo ment um) of the vehicle into therma l (heat). When stepping on the brakes, the driver comma nds a stopping force ten t imes as powerfu l as the force that puts the car in motion. The braking system can exert thousands of pounds of pressure on each of the four brakes. The brake system is composed of the follow ing basic compone nts : the “master cylinder” which is located under the hood, and is directly 外文资料译文 5 connected to the brake pedal, converts driver foots mechanical pressure into hydraulic pressure. Steel “brake lines” and flexible “brake hoses” connect the master cylinder to the “slave cylinders” located at each wheel. Brake fluid, specially designed to work in extreme condition, fills the system. “Shoes” and “Pads” are pushed by the salve cylinders to contact the “drum” and “rotors” thus causing drag, which (hopefully) slows the car. The typ ical brake system cons ists of disk brakes in fro nt and eit her disk or drum brakes in the rear connected by a syste m of tubes and hoses that link the brake at each wheel to the master cylinder. Stepping o n the brake pedal, a plunger is actually been pushing against in the master cylinder which forces hydr aulic oil (brake fluid) through a series of tubes and hoses to the braking unit at each wheel. S ince hydraulic fluid (or any fluid for that matter) cannot be compressed, pushing fluid through a p ipe is just like pushing a steel bar through pipe. Unlike a s teel bar, however, fluid can be directed through many tw ists and turns on its way to its destinat ion, arriving with the exact same motion and pressure that it started wit h. It is very important that the fluid is pure liq uid and that there is no air bubbles in it. A ir can compress which causes sponginess to the pedal and severely reduced braking efficie ncy. If air is suspected, then the system must be bled to remove the air. There are “bleeder screws” at each wheel and caliper for this purpose. O n disk brak es, the fluid from t he master cylinder is forced into a caliper where it pressure against a piston. The piton, in - turn, squeezes two brake pads aga inst the disk (rotor) which is attached to the wheel, forcing it to slow down or stop. This process is simila r to the wheel, caus ing the wheel to stop. In eit her case, the fr ict ion sur face of the pads on a disk brake system, on the shoes on a drum brake convert the forward mot ion of t he vehic le into heat. Heat is w hat causes the fr ict ion surfaces (lining) of the pads and shoes to eventua lly wear out and 外文资料译文 6 require replacement. Brake fluid is spec ial oil t hat has specifics propert ies. It is designed to withsta nd cold temperatures wit hout thickening as well as very high te mperatures wit hout boiling. (I f the brake fluid sho uld boil, it w ill cause you to have a spongy pedal and the car will be hard to stop). The brake fluid reservoir is on top of t he master cylinder. Most cars today have a transparent reservoir so that yo u can see the leve l wit hout opening the cover. The brake fluid lever w ill drop slight ly as the brake pads wear. This is a nor ma l condit io n and no cause for concern. If t he le ver drops not iceably over a short period of t ime or goes down to about two thirds full, have your brakes checked as soon as possib le. Keep the reservoir covered expect for the amount of t ime you need to fill it and never leave a can of brake fluid uncovered. Brake fluid must ma inta in a very high bo iling point. E xposure to air w ill cause the fluid to absorb moisture which will lower that boiling point. The brake fluid trave ls from t he master cylinder to the whee ls through a series of steel t ubes and reinforced rubber hoses. Rubber hoses are only used in places that require flexib ility, such as at the front w heels, which move up and dow n as well as steer. The rest of the system uses non-corrosive seamless steel tubing wit h specia l fitt ings at attachment points. If a steel line requires a repair, the best procedure is to rep lace the co mplete line. If this is nit practica l, a line can be repaired us ing specia l splice fit t ings that are made for brake system repair. You must never use brass “compression” fittings or copper tubing repair a brake system. They are dangerous and illegal. 3.2.1 Other Components in the Hydraulic System Proportioni ng Valve or Equalizer Valve 外文资料译文 7 These va lves are mo unted between the master cylinder and the rear wheels. T hey are designed to adjust t he pressure between the front and the rear brakes depending on how hard you are stopping. The shorter you stop, the more of the vehicles weight is transferred to the front wheels, in some cases, causing t he rear to lift and the front to dive. These va lves are designed to direct more pressure to the front and less pressure to the harder you stop. This minimizes the chance of premature lockup at the rear wheels. Pressure Differential Valve This va lve is usua lly mounted just below the master and is responsib le for tur ning the brake warning light on when it detects a ma lfunct ion. It measures the pressure fro m the two sections of the master cylinder and compares the m. S ince it is mo unted ahead of the proportio ning or equalizer valve, the two pressures it detects should be equa l. If it detects a difference, it means that there is probably a brake fluid leak somewhere in the system. 外文资料译文 8 3 1 离合器 发动机产生动力 来驱动汽 车，它通过传 动系把动力 传递到车轮 上，传动系包含从飞轮 到车轮的 所有零件。 这些零件含 离合器、变 速箱，驱动桥和最后的驾 驶总成。 离合器含飞轮、离 合器压盘、离 合器从动盘、弹 簧 、压盘盖和操作离合器所需的 连杆组，连 杆组是引擎 和变速箱之 间的一个旋 转机构 ，它装在离合器和变 速器之间 ，离合器通 过来自在两 零件之间的 接触的磨擦力来工作 ，这就是 离合器为 什么叫做一 个磨擦机构 。在啮 合之后 ，离合器一定要依靠 磨擦连续 传递所有的 引擎扭力到 变速箱而中 间不会有滑移。每当变速 箱的齿轮 由于换挡被 移 动时，离 合器就用来 断开来自引擎的动力。 为了要启动引擎或 者移动齿 轮，驾驶员 必须踩下离 合器踏板达 到把变速器和引擎 分离的目 的。同时 ,对变速箱 输入轴的连 接的被动的 构件是或不动或者对 引擎曲轴 被连接的构 件以一个比 较慢的速度 旋转。没有弹簧压力在关 键的总成 零件上时， 就没有主动 的构件和被 动的构件之间的磨擦。驾 驶员松开 离合器踏板 ,离合 器部件上的 弹簧压力增大，零件之间的磨 擦也增加 。驾驶员通 过控制离合 器踏板和连 杆组来控制弹簧的压力。 主从动部 件的结合使 他们之间的 摩擦成为可 能。当整个弹簧压力被应 用的时候 ，主从动部 件之间速度 应该是相同 的。此时，离合器成为一 个联结装 置，传递所 有的引擎动 力到变速箱 ，而不会有滑动。 然而，变速箱应该 被逐渐地 连接到引擎 从而能平顺 地操作车而 且在驾驶时能获得较 小的扭转 陡震因为此 时引擎仅仅 被使用了很 少的动力。另外，主动构 件太快地 与被动的构 件一起连接 ，引擎可能 会被熄灭。 飞轮是离合器的一 个主要部 分。它连接 在引擎曲轴 上并把引擎 动力传递到离合器总 成上。飞 轮通过连接 从动盘和压 盘来传递从 引擎到外文资料译文 9 副箱的动力。 飞轮能很好的为离 合器总成 提供一个合 适的位置。 当离合器被 应用的时候，飞轮把 引擎扭力 转移到离合 器。因为它 的重量，飞 轮能够使引擎平顺地运 作。飞轮在 它的外部边 缘有一个齿 圈 ,在起动电动机 上用一个驱动小齿轮 来和它啮 合。 离合器从动盘装在 飞轮和压 盘之间。离 合器从动盘 上有一花键 毂和变速箱输入轴过 盈配合。 花键毂和轴 上的花键联 接。这些花 键装在槽中。因此，这 二个零件就 连在了一起 。然而 ,从动盘在 轴上可能往 前或后圆运动。从动 盘和轴一 起旋转。 离合器压盘通常是 用铸铁做 成的。它是 圆的，与离 合器从动盘 有相同的直径。压盘 的一个边 是光滑的。 这一个边将 会压着的离 合器从动盘压向飞轮 。外部的 边有促进 弹簧和分离 机构结合的 轮磨配件 。 这个压盘总成的主要 的两个形 式 是螺旋弹 簧总成和膜 片弹簧。 弹簧推动对抗盖。从动片和压板都没有被刚性地被连接到飞轮上，两者可以向它移动 也可以离 开。当离合 器踏板压向 止推轴承的 推力轴瓦的时候飞轮被压 。压向支 点使他们在 一端以推力 轴瓦连接， 而且压板另一端把压板拉 回来压向 它的弹簧。 这在将齿轮 箱从引擎分 离出来的从动片上释放压 力。 膜片弹簧压板总成 广泛地被 用于现代的 大多数汽车 上。当压力 对它被应用的时候， 膜片弹簧 是一个单薄 的形状。当 压力被移动 时它变成最初的形状。膜 片弹簧的 中央部分进 入担任释放 杆的多数的 手指之内被纵切。当离合 器总成和 引擎输出轴 一起旋转那 些重力被离 心板所投而且导致分离杆 杆压向压 板。在离合 器的不工作 期间，指端 被分离轴承向前移动，弹 簧支点在 支撑环上和 输出轴移动 远离飞轮， 伸缩弹簧拉着压板远离离 合器片使 离合器脱离 工作。 分离轴承工作时膜 片弹簧移 向变速器。 在枢上的隔 膜枢嵌环它 的外部辋强迫对抗离 合器的压 板以便离合 器片被连接 到飞轮上。 隔膜型压板总成 的优点是 它的紧凑结 构，比较低的 重量 ,比较少的移动零件 ,比 较少的连接 ,在 压盘周围提 供一个平衡 力来降低旋 转平衡和更少的离合器滑 移几率。 离合器踏板被连接 到自由机 构或一个高 压线或 ,更普遍 ,或一个 水外文资料译文 10 力系统。任一方法 ,踩下 踏板可推 动分离轴承 向前运动进 而压向压盘 使离合器与飞轮分离 。由一个 水力的机构 ，离合器踏 板臂在离合 器主泵中操作一个活塞。 其他零件包括离 合器叉 ,分离轴 承 ,离合器壳，离合 器壳盖 ,分离轴衬连接和分离变速 箱。离合 器叉 ,和连杆组连 接 ,实 际上是操作 离合器的。分离轴承装在 离合器叉 和压板总成 之间。离合 器盖装在离 合器总成上。离合器盖紧 固到离合 器壳的底部 。这个可移 动的盖可以 让一个机匠不用去除变 速箱和壳 就可以检验 离合器。导轴 衬装在曲轴 的后部 ，并支撑变速箱输入