汽车专业英语2版参考译文 - 第5章 制动系统
汽车制动系统(机械、车辆工程毕业论文英文文献及翻译)
Automobile Brake SystemThe braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes, the driver commands a stopping force ten times as powerful 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.Two complete independent braking systems are used on the car. They are the service brake and the parking brake.The service brake acts to slow, stop, or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. The primary purpose of the brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by when a separate parking brake foot pedalor hand lever is set.The brake system is composed of the following basic components: the “master cylinder” which is located under the hood, and is directly connected to the brake pedal, converts driver foot’s 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 conditions, fills the system. “Shoes” and “pads” are pushed by the slave cylinders to contact the “drums” and “rotors” thus causing drag, which (hopefully) slows the car.The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder (Figure).Basically, all car brakes are friction brakes. When the driver applies the brake, the control device forces brake shoes, or pads, against the rotating brake drum or disks at wheel. Friction between the shoes or pads and the drums or disks then slows or stops the wheel so that the car is braked.In most modern brake systems (see Figure 15.1), there is a fluid-filled cylinder, called master cylinder, which contains two separate sections, there is a piston in each section and both pistons are connected to a brake pedal in the driver’s compartment. When the brake is pushed down, brake fluid is sent from the master cylinder to the wheels.At the wheels, the fluid pushes shoes, or pads, against revolving drums or disks. The friction between the stationary shoes, or pads, and the revolving drums or disks slows and stops them. This slows or stops the revolving wheels, which, in turn, slow or stop the car.The brake fluid reservoir is on top of the master cylinder. Most cars today have a transparent r reservoir so that you can see the level without opening the cover. The brake fluid level will drop slightly as the brake pads wear. This is a normal condition and no cause for concern. If the level drops noticeably over ashort period of time or goes down to about two thirds full, have your brakes checked as soon as possible. Keep the reservoir covered except for the amount of time you need to fill it and never leave a cam of brake fluid uncovered. Brake fluid must maintain a very high boiling point. Exposure to air will cause the fluid to absorb moisture which will lower that boiling point.The brake fluid travels from the master cylinder to the wheels through a series of steel tubes and reinforced rubber hoses. Rubber hoses are only used in places that require flexibility, such as at the front wheels, which move up and down as well as steer. The rest of the system uses non-corrosive seamless steel tubing with special fittings at all attachment points. If a steel line requires a repair, the best procedure is to replace the compete line. If this is not practical, a line can be repaired using special splice fittings that are made for brake system repair. You must never use copper tubing to repair a brake system. They are dangerous and illegal.Drum brakes, it consists of the brake drum, an expander, pull back springs, a stationary back plate, two shoes with friction linings, and anchor pins. The stationary back plate is secured to the flange of the axle housing or to the steering knuckle. The brake drum is mounted on the wheel hub. There is a clearance between the inner surface of the drum and the shoe lining. To apply brakes, the driver pushes pedal, the expander expands the shoes and presses them to the drum. Friction between the brake drum and the friction linings brakes the wheels and the vehicle stops. To releaseAnti-lock brake systems make braking safer and more convenient, Anti-lock brake systems modulate brake system hydraulic pressure to prevent the brakes from locking and the tires from skidding on slippery pavement or during a panic stop.Anti-lock brake systems have been used on aircraft for years, and some domestic car were offered with an early form of anti-lock braking in late 1990’s. Recently, several automakers have introduced more sophisticated anti-lock system. Investigations in Europe, where anti-lock brakin g systems have been available for a decade, have led one manufacture to state that the number of traffic accidents could be reduced by seven and a half percent if all cars had anti-lock brakes. So some sources predict that all cars will offer anti-lock brakes to improve the safety of the car.Anti-lock systems modulate brake application force several times per second to hold the tires at a controlled amount of slip; all systems accomplish this in basically the same way. One or more speed sensors generate alternating current signal whose frequency increases with the wheel rotational speed. An electronic control unit continuously monitors these signals and if the frequency of a signal drops too rapidly indicating that a wheel is about to lock, the control unit instructs a modulating device to reduce hydraulic pressure to the brake at the affected wheel. When sensor signals indicate the wheel is again rotating normally, the control unit allows increased hydraulic pressure to the brake. This release-apply cycle occurs several time per second to “pump” the brakes like a driver might but a t a much faster rate.In addition to their basic operation, anti-lock systems have two other things in common. First, they do not operate until the brakes are applied with enough force to lock or nearly lock a wheel. At all other times, the system stands ready to function but does not interfere with normal braking. Second, if the anti-lock system fail in any way, the brakes continue to operate without anti-lock capability. A warning light on the instrument panel alerts the driver when a problem exists in the anti-lock system.The current Bosch component Anti-lock Braking System (ABSⅡ), is a second generation design wildly used by European automakers such as BWM,Mercedes-Benz and Porsche. ABSⅡsystem consists of : four wheel speed sensor, electronic control unit and modulator assembly.A speed sensor is fitted at each wheel sends signals about wheel rotation to control unit. Each speed sensor consists of a sensor unit and a gear wheel. The front sensor mounts to the steering knuckle and its gear wheel is pressed onto the stub axle that rotates with the wheel. The rear sensor mounts the rear suspension member and its gear wheel is pressed onto the axle. The sensor itself is a winding with a magnetic core. The core creates a magnetic field around the winding, and as the teeth of the gear wheel move through this field, an alternating current is induced in the winding. The control unit monitors the rate o change in this frequency to determine impending brake lockup.The control unit’s function can be divided into three parts: signal processing, logic and safety circuitry. The signal processing section is the converter that receives the alternating current signals form the speed sensors and converts them into digital form for the logic section. The logic section then analyzes the digitized signals to calculate any brake pressure changes needed. If impending lockup is sensed, the logic section sends commands to the modulator assembly.Modulator assemblyThe hydraulic modulator assembly regulates pressure to the wheel brakes when it receives commands from the control utuit. The modulator assembly can maintain or reduce pressure over the level it receives from the master cylinder, it also can never apply the brakes by itself. The modulator assembly consists of three high-speed electric solenoid valves, two fluid reservoirs and a turn delivery pump equipped with inlet and outlet check valves. The modulator electrical connector and controlling relays are concealed under a plastic cover of the assembly.Each front wheel is served by electric solenoid valve modulated independently by the control unit. The rear brakes are served by a single solenoid valve and modulated together using the select-low principle. During anti-braking system operation, the control unit cycles the solenoid valves to either hold or release pressure the brake lines. When pressure is released from the brake lines during anti-braking operation, it is routed to a fluid reservoir. There is one reservoir for the front brake circuit. The reservoirs are low-pressure accumulators that store fluid under slight spring pressure until the return delivery pump can return the fluid through the brake lines to the master cylinder.汽车制动系统制动系统是汽车中最重要的系统。
制动系统外文翻译
附录1BRAKE SYSTEMThe braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).The brake system is composed of the following basic components: the “master cylinder” 、“brake lines” 、“brake hoses” 、“slave cylinders” . “brake disk” “filler block” and so on.The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder .Stepping on the brake pedal, a plunger is actually been pushing against in the master cylinder which forces hydraulic oil (brake fluid) through a series of tubes and hoses to the braking unit at each wheel. Since hydraulic fluid (or any fluid for that matter) cannot be compressed, pushing fluid through a pipe is just like pushing a steel bar through a pipe. Unlike a steel bar, however, fluid can be directed through many twists and turns on its way to its destination, arriving with the exact same motion and pressure that it started with. It is very important that thefluid is pure liquid and that there are no air bubbles in it. Air can compress, which causes a sponginess to the pedal and severely reduced braking efficiency. If air is suspected, then the system must be bled to remove the air. There are “bleeder screws” at each wheel cylinder and caliper for this purpose.With drum brakes, fluid is forced into the wheel cylinder which pushes the brake shoes out so that the friction linings are pressed against the drum which is attached to the wheel, causing the wheel to stop.On a disk brake, the fluid from the master cylinder is forced into a caliper where it presses against a piston. The piston, in-turn, squeezes two brake pads against the disk(rotor)which is attached to the wheel, forcing it to slow down or stop. This process is similar to a bicycle brake where two rubber pads rub against the wheel rim creating friction.In either case, the friction surfaces of the pads on a disk brake system, or the shoes on a drum brake convert the forward motion of the vehicle into heat. Heat is what causes the friction surfaces (linings) of the pads and shoes to eventually wear out and require replacement.Drum BrakesSo if disk brakes are so great, how come we still have cars with The reason is cost. While all vehicles produced for many years have disk brakes on the front, drum brakes are cheaper to produce for the rearwheels. The main reason is the parking brake system. On drum brakes, adding a parking brake is the simple addition of a lever, while on disk brakes, we need a complete mechanism, in some cases, a complete mechanical drum brake assembly inside the disk brake rotor! Parking brakes must be a separate system that does not use hydraulics. It must be totally mechanical, but more on parking brakes laterWheel CylinderThe wheel cylinder consists of a cylinder that has two pistons, one on each side. Each piston has a rubber seal and a shaft that connects the piston with a brake shoe. When brake pressure is applied, the pistons are forced out pushing the shoes into contact with the drum. Wheel cylinders must be rebuilt or replaced if they show signs of leaking.Brake ShoesLike the disk pads, brake shoes consist of a steel shoe with the friction material or lining riveted or bonded to it. Also like disk pads, the linings eventuallywear out and must be replaced. If the linings are allowed to wear through to the bare metal shoe, they will cause severe damage to the brake drum.Backing PlateThe backing plate is what holds everything together. It attaches to the axle and forms a solid surface for the wheel cylinder, brake shoes andassorted hardware. It rarely causes any problemsReading material：Disk BrakeDisk brakes, like many automotive innovations, were originally developed for auto racing, but are now standard equipment on virtually every car made. On most cars, the front brake are of the disc type, and the rear brakes are of the “drum” type. Drum brakes use two semi-circular shoes to press outward against the inner surfaces of a steel drum. Older cars often had drum brakes on all four wheels, and many new have 4-wheel disc brakes.Though disc brakes rely on the same basic principles to slow a vehicle (friction and heat), their design is far superior to that of drum brakes. Because disc brakes can fling off water more easily than drum brakes, they work much better in wet conditions. This is not to say that water does not affect them, it definitely does. If you splash through a puddle and then try to apply the brakes, your brakes may not work at all for a few seconds！Disc brakes also allow better airflow cooling, which also increases their effectiveness. Some high performance disc brakes have drilled or slotted holes through the face of the rotor, which helps to prevent the pads from “glazing” (becoming hardened due to heat). Disc brakes were introduced as standard equipment on most cars in the early seventies.译文制动系统制动系统是汽车中要紧的系统之一。
制动系统--文献翻译
Brake systemAutomobile brake is the most important system in cars.Brake are actually energy conversion ,which convert the kinetic energy of the vehicle into thermal energy .When stepping on the brakes,the drive commands a stopping force ten times as p owerful as the force that puts the cars in motin .The brakeing system can exert thousands of pounds of pressure on each of the four brakes.Each vehicle must have two indenpent brake s ystems for safety.The main brake s ystem which is locate under the hoo d and is directly connect to the brake pedal is hydraulically operated and is called the service brake system.The secondary or parking brake system is mechanically operated.To increase safety ,most modern car brake system are broken into two circuits,with two wheels on each circuit.There is a fluid-filled cylinder,called the master cylinder .It supplies pressure to hoth circuits of the car ,and if a fluid leak occurs in one circuit ,only two of the wheels will lose their brakes and the car will be stopped.Why that pushig down on the brake pedal can slow a car to stop? How dose the car transmits the force from the driver’leg to its wheel? It is the work that brakes did.Layout of Typical Brake system When depressing the breke pedal ,the car transmits the force the drive’s foot to its brakes through a fluid.Since the actual brakes require a much greater force than the drive could apply with his leg ,the car must also multipy the force of the driver’s foot.It dose this in two ways: mechanical advantage a nd hydraulic force multiplication .Leverge The pedal is designed in such a way that it can multiply the force from the driver’s leg several times before any force is even transmitted to the brake fluid.In the figure above ,a force F is being applied t o the left end of the lever.The left end of the lever is twice as long 2X) as the right end (x).Therefore ,on the right end of the lever a force of 2F is available,but it acts through half of the distans (Y) that the left end moves (2Y) .Changing the relat ive lengths of the left and right ends of the lever changes the mulitipliers.Hydraulic Brake Systems The hydraulic system is that force applied at one point is thansmitted to another point using an incompressible fluid , almost alwaays an oil of some so rt .Most brake systems also muitiply the force in the process .The great thing about hydraulic systems is that the pipe connecting the two cylinders can be any length and shape , allowing it to snake through all sorts of things separating the two pistons .The pipe can also fork ,so that one master cylinder can drive more than one salve cylinder if desired .The other neat thing about a hydraulic s ystem is that it makes force multiplicationfairly eas y . In a hydralic system , all you have to do change the si ze of one piston and cylinder to the other .The automobile brake systems are divided into three t ypes of service brake combinations:drum brake , disc brakes and disc-drum combinations.Drum Brake It uses an internal expanding brake shoe with the lining attactet , working within the confines of a rotating brake surface called a brake drum .The brake shoe diameter is expanded to contact the brake surface by a hydraulic cylinder that is referred to as a wheel cylinder . With drum brake , the fluid is forced into the wheel cylinde which pushed the brake shoes out so that the friction lining are pressed againtst the drum , and cause the wheel to stop .Power brakes back in the day , when most cars had drum brakes ,power brakes were not really necessary ---- drum brakes naturally provide some of their own power assist .Since most cars today have disc brakes ,at least on the front wheels , they need power brakes,Without this device ,a lot of drivers would have very tired legs .The brake booster use Vacuum from the engine to multipiy the force that your foot applies to the master cylinder .Disc Brakes Most modern cars have disc brake on the front wheels , and some have disc brakes on all four wheels ,Disc brakes employ a brake disc that rotates with the wheel ,so it is usually referred to as a brake rotor . On a disc brake , the fluid from the master cylinder is forced into a caliper where it presses against a piston ,in—turn , squeezes two brake pads against the disk which is attached to the wheel ,forcing it to slow down or stop .This process is similar to a bicycle brake where two rubber pads rub against the wheel rim creating friction.The most common type of disc brake on modern cars is the single-piston floating caliper.Self-Adjusting brakes The single-piston floating-caliper disc brake is self-centering and self-adjusting .The caliper is able to slide from side to side so it will move to the center each time the brakes are applied .Also,since there is no spring to pull the pads away from the disc ,the pads always stay in light contact with the rotor .This is important because the pistons in the brakes are much larger in diameter than the ones in the master cylinder .If the brake pistons retracted into their cylinders ,it might take several applications of the brake pedal to pump enough fluid into the brake cylinder to engage the brake pads.Self-Adjusting disc brake Older cars had dual or four-pistin fixed-caliper desiger .A piston on each side of the rotor pushed the padon that side .This design has b een largel y eliminated becausesingle-piston designs are cheaper and more reliable .Emergence Brakes In cars with disc brakes on all four wheels ,an emergency brake has to be actuated by a separate mechanism than the primary brakes in case of a total pr imary brake failure .Most cars use a cable to actuate the emergency brake .Some cars with four-wheel disc brakes have a separate drum brake integrated into the hub of the rear wheels .This drum brake is only for the emergency brake sysem ,and it is actuate d only by the cable;it has no hydraulics .Parking Brakes Cars also have the parking brake system .It is used to hold one or more of the vehicle brakes in an applied position for an extended period of time .This brake system must be capable of holding the vehicle on a grade and bringing the vehicie to a stop if the service brakes fail .The parking brake system used on most current model passenger vehicles operates by applying two rear-wheel brakes through a mechanical system of cable and levers.There are air brakes,anti-lock brakes,too .The forme used in heavy trucks and utilizes compressed air as a source of force to stop the truck .The latter used for solving the lockup problem: it can rapidly pump the brakes whenever the system detects a wheel that is locked up .This pumping of the brakes occurs at ten or more times a second ,far fasrer than a human can pump the brake manually.Post-Sale Service and CallbackThe automobile post-sale service means the sale branch provides all the technical service to the customer before or after they buy the car .It may carry on in pre-sale ,or when selling carries on .What but are more is sells after the vehicles ,cerris on the quality guarantee ,the routine maintenance ,the repair ,the technical consultation and the spare parts supply according to the deadline and so on a series of work .In recent years ,the products performances ,product qualities and product prices are almost convergence the same among those famous international automobile compani es .As a result ,the focus of competition in the market focus and transfer to post-sale .Post-sale functions should be enable to use good car products and to create the best returns ,and thus can prove the successful post-sale work .A perfect post-sale service should have two function : to serve both customers and companies themselves .For customers ,the post-sale service could satisfy them and help them solve problems ;for the companies themselves ,it could accurately reflect product utility information ,quality information ,and important social information ,so that the company can make right decisions based on them .Automobile is the most typical product which highl y unifies thesale and the post-sale service .In the intermation market ,one important criterion for automobile sale agent is whethe they have and fulfill post-sale service .When a customer wants to purchase a car ,the first thing he asks is where to repaire the car and whether there are spare-parts .Only getting postive replies ,will he think of other things .Big automobile companies from Eupope ,the US and Japan all recognize that the first car is sold by sales personnel ,but the second car mainly relies on good post-sale service .The automobile is a big product ,so it is very difficult to f ulfill all kinds of post-sale service only depending upon manufaturers .Usually ,a service network undertakes all technical service for manufacturers.In foreign countries ,the post-sale service network is usually linked with sales network .So it can provid e technical service while selling automobile .And the post-sale service network is composed by distributors ,agents and repairing shops .Post-sale service itself belongs to the technical service category.Automobile is hightly technology-intensive ,so the post-sale service includes technical guidance ,technical consultation ,and technical demonstration and so on .Main points which need to be introduced to the society ,dealers ,post-sale service network and customers are completely done by post-sale department .On the other hand ,as a post-sale service man ,one should make sure that you have satisfied your customers when doing your work ,and should make it clear that you want to know if there are any problems with you work ,no matter when they develop .Since you made the project ,you are naturally the best person to service it ,if and when the need arises .Make this clear to your client .Nobody likes callbacks ,and if you’ve done your job well ,you should have few ,if any ,for months or years after the in stallation or delivery.But let the client know that for repairs that result fromordinary use ,you’ll be glad to keep your work looking and working like new---for a modest fee ,of course .If ,however ,problems arise that are clearl y due to shoddy workmanship ,it is incumbent on you to correct them free of charge .This is ,of course ,perhaps the best reason to get it right the first time .There’s no trick to determine whether you are being called back because of a problem due to you workmanship or the clie nt’t use of the unit .Like everything else we’ve covered in this series ,doing right by your customers is just a matter of honesty .Put honesty into practice as part of your selling system and you’ll find that it is the best way to do what is right for you r business ,too .A checklist for maintaining good customer relations:Do anything you can to help the client visualize in advance how the finished project will look .Don’t give ballpark prices unless you already have a well established relationship with the client .Use customers as references ,but only when you are sure they are totally satisfied.Tell customers you want to know if there are problems with your work and that you can provide any routine service .In everything you do ,be honest with your c lient .Automobile callback system originated from the U.S in 1960s .Now it is not new in the U.S.,European countries ,Japan and South Korea .The U.S.has the longest history of automobile callback and the most strict regulations .Until now ,the American gr and has totally recalled more than 200 million vehicles since 1966 ,and more than 24 million tires ,including passenger vehicle ,trucks ,buses ,motorcycles and so on ,And nearly all auto manufactures in the world have recalled cases in the U.S.China’s Fla w Automobile Prosuct Management Stipulation wasimplemented since October1 ,2004 .Automobile is the machine which is assembled by tens of thousands of components and it is not strang to have this kind of flaw or that kind in materials or designs .But most flaws are recessive ,so they will be gradually exposed after using a period of time and people can then realize the flaw’s existence .Sometimes some batch of vehicle components processing ,assembly or material formula change ,and they possibly bring the flaws .The scope of callback s ystem is extremely explicit ,that is the flaw has to be associated with safet y and should appear in the batch .Recall system mainly aims at the systematic and unified flaws which are related with safety and existing in one batch of vehicles .The goal of the automobile recall is to eliminate the flaw and hidden danger ,ensure the public security ,the public benefit and the social economic order .制动系统制动系统是汽车中最重要的系统，它实际上是个能量转换装置，它把动能转化为内能。
汽车制动系统外文翻译
Automobile Brake SystemThe braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes, the driver commands a stopping force ten times as powerful 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.Two complete independent braking systems are used on the car. They are the service brake and the parking brake.The service brake acts to slow, stop, or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. The primary purpose of the parking brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by when a separate parking brake foot pedal or hand lever is set.The brake system is composed of the following basic components: the “master cylinder” which is located under the hood, and is directly connected to the brake pedal, converts driver foot’s 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 conditions, fills the system. “Shoes” and “pads” are pushed by the slave cylinders to contact the “drums” and “rotors” thus causing drag, which (hopefully) slows th e car.The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder (Figure).Basically, all car brakes are friction brakes. When the driver applies the brake, the control device forces brake shoes, or pads, against the rotating brake drum or disks at wheel. Friction between the shoes or pads and the drums or disks then slows or stops the wheel so that the car is braked.In most modern brake systems (see Figure 15.1), there is afluid-filled cylinder, called master cylinder, which contains two separate sections, there is a piston in each section and both pistons are connected to a brake pedal in the driver’s compartment. W hen the brake is pushed down, brake fluid is sent from the master cylinder to the wheels.At the wheels, the fluid pushes shoes, or pads, against revolving drums or disks. The friction between the stationary shoes, or pads, and the revolving drums or disks slows and stops them. This slows or stops the revolving wheels, which, in turn, slow or stop the car.The brake fluid reservoir is on top of the master cylinder. Most cars today have a transparent reservoir so that you can see the level without opening the cover. The brake fluid level will drop slightly as the brake pads wear. This is a normal condition and no cause for concern. If the level drops noticeably over ashort period of time or goes down to about two thirds full, have your brakes checked as soon as possible. Keep the reservoir covered except for the amount of time you need to fill it and never leave a cam of brake fluid uncovered.Brake fluid must maintain a very high boiling point. Exposure to air will cause the fluid to absorb moisture which will lower that boiling point.The brake fluid travels from the master cylinder to the wheels through a series of steel tubes and reinforced rubber hoses. Rubber hoses are only used in places that require flexibility, such as at the front wheels, which move up and down as well as steer. The rest of the system uses non-corrosive seamless steel tubing with special fittings at all attachment points. If a steel line requires a repair, the best procedure is to replace the compete line. If this is not practical, a line can be repaired using special splice fittings that are made for brake system repair. You must never use copper tubing to repair a brake system. They are dangerous and illegal.Drum brakes, it consists of the brake drum, an expander, pull back springs, a stationary back plate, two shoes with friction linings, and anchor pins. The stationary back plate is secured to the flange of the axle housing or to the steering knuckle. The brake drum is mounted on the wheel hub. There is a clearance between the inner surface of the drum and the shoe lining. To apply brakes, the driver pushes pedal, the expander expands the shoes and presses them to the drum. Friction between the brake drum and the friction linings brakes the wheels and the vehicle stops. To release brakes, the driver release the pedal, the pull back spring retracts the shoes thus permitting free rotation of the wheels.Disk brakes, it has a metal disk instead of a drum. A flat shoe, or disk-brake pad, is located on each side of the disk. The shoes squeeze the rotatin g disk to stop the car. Fluid from the master cylinderforces the pistons to move in, toward the disk. This action pushes the friction pads tightly against the disk. The friction between the shoes and disk slows and stops it. This provides the braking action. Pistons are made of either plastic or metal. There are three general types of disk brakes. They are the floating-caliper type, the fixed-caliper type, and the sliding-caliper type. Floating-caliper and sliding-caliper disk brakes use a single piston. Fixed-caliper disk brakes have either two or four pistons.The brake system assemblies are actuated by mechanical, hydraulic or pneumatic devices. The mechanical leverage is used in the parking brakes fitted in all automobile. When the brake pedal is depressed, the rod pushes the piston of brake master cylinder which presses the fluid. The fluid flows through the pipelines to the power brake unit and then to the wheel cylinder. The fluid pressure expands the cylinder pistons thus pressing the shoes to the drum or disk. If the pedal is released, the piston returns to the initialposition, the pull back springs retract the shoes, the fluid is forced back to the master cylinder and braking ceases.The primary purpose of the parking brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by the driver when a separate parking braking hand lever is set. The hand brake is normally used when the car has already stopped.A lever is pulled and the rear brakes are approached and locked in the “on” position. The car may now be left without fear of its rolling away. When the driver wants to move the car again, he must press a button before the lever can be released. The hand brake must also be able to stop the car in the event of the foot brake failing.For this reason, it is separate from the foot brake uses cable or rods instead of the hydraulic system.Anti-lock Brake SystemAnti-lock brake systems make braking safer and more convenient, Anti-lock brake systems modulate brake system hydraulic pressure to prevent the brakes from locking and the tires from skidding on slippery pavement or during a panic stop.Anti-lock brake systems have been used on aircraft for years, and some domestic car were offered with an early form of anti-lock braking in late 1990’s. Recently, several automakers have introduced more sophisticated anti-lock system. Investigations in Europe, where anti-lock brakin g systems have been available for a decade, have led one manufacture to state that the number of traffic accidents could be reduced by seven and a half percent if all cars had anti-lock brakes. So some sources predict that all cars will offer anti-lock brakes to improve the safety of the car.Anti-lock systems modulate brake application force several times per second to hold the tires at a controlled amount of slip; all systems accomplish this in basically the same way. One or more speed sensors generate alternating current signal whose frequency increases with the wheel rotational speed. An electronic control unit continuously monitors these signals and if the frequency of a signal drops too rapidly indicating that a wheel is about to lock, the control unit instructs a modulating device to reduce hydraulic pressure to the brake at the affected wheel. When sensor signals indicate the wheel is again rotating normally, the control unit allows increased hydraulic pressure to the brake. This release-apply cycle occursseveral time per second to “pump” the brakes like a driver mig ht but at a much faster rate.In addition to their basic operation, anti-lock systems have two other things in common. First, they do not operate until the brakes are applied with enough force to lock or nearly lock a wheel. At all other times, the system stands ready to function but does not interfere with normal braking. Second, if the anti-lock system fail in any way, the brakes continue to operate without anti-lock capability. A warning light on the instrument panel alerts the driver when a problem exists in the anti-lock system.The current Bosch component Anti-lock Braking System (ABSⅡ), is a second generation design wildly used by European automakers such as BWM, Mercedes-Benz and Porsche. ABSⅡ system consists of : four wheel speed sensor, electronic control unit and modulator assembly.A speed sensor is fitted at each wheel sends signals about wheel rotation to control unit. Each speed sensor consists of a sensor unit and a gear wheel. The front sensor mounts to the steering knuckle and its gear wheel is pressed onto the stub axle that rotates with the wheel. The rear sensor mounts the rear suspension member and its gear wheel is pressed onto the axle. The sensor itself is a winding with a magnetic core. The core creates a magnetic field around the winding, and as the teeth of the gear wheel move through this field, an alternating current is induced in the winding. The control unit monitors the rate o change in this frequency to determine impending brake lockup.The control unit’s function can be divided into three parts: signal processing, logic and safety circuitry. The signal processing sectionis the converter that receives the alternating current signals form the speed sensors and converts them into digital form for the logic section. The logic section then analyzes the digitized signals to calculate any brake pressure changes needed. If impending lockup is sensed, the logic section sends commands to the modulator assembly.Modulator assemblyThe hydraulic modulator assembly regulates pressure to the wheel brakes when it receives commands from the control utuit. The modulator assembly can maintain or reduce pressure over the level it receives from the master cylinder, it also can never apply the brakes by itself. The modulator assembly consists of three high-speed electric solenoid valves, two fluid reservoirs and a turn delivery pump equipped with inlet and outlet check valves. The modulator electrical connector and controlling relays are concealed under a plastic cover of the assembly.Each front wheel is served by electric solenoid valve modulated independently by the control unit. The rear brakes are served by a single solenoid valve and modulated together using the select-low principle. During anti-braking system operation, the control unit cycles the solenoid valves to either hold or release pressure the brake lines. When pressure is released from the brake lines during anti-braking operation, it is routed to a fluid reservoir. There is one reservoir for the front brake circuit. The reservoirs arelow-pressure accumulators that store fluid under slight spring pressure until the return delivery pump can return the fluid through the brake lines to the master cylinder.汽车制动系统制动系统是汽车上最重要的系统。
车辆工程外文翻译---制动系统
附录1Brake Systems1.Drum vs. DiscBrake technology, just like suspension technology and fuel-system technology, has come a long way in recent years.1）Drum BrakesEarly automotive brake systems, after the era of hand levers of course, used a drum design at all four wheels. They were called drum brakes because the components were housed in a round drum that rotated along with the wheel. Inside was a set of drum that, when the brake pedal was pressed, would force the shoes against the drum and slow the wheel. Fluid was used to transfer the movement of the brake pedal into the movement of the brake shoes, while the drum themselves were made of heat-resistant friction material similar to that used on clutch plates.This basic design proved capable under most circumstances, but it had one major flaw. Under high braking conditions, like descending a steep hill with a heavy load or repeated high-speed slow downs, drum brakes would often fade and lose effectiveness. Usually this fading was the result of too much heat build-up within the shoes. Remember that the principle of braking involves turning kinetic energy (wheelmovement) into thermal energy (heat). For this reason, drum brakes can only operate as long as they can absorb the heat generated by slowing a vehicle's wheels. Once the brake components themselves become saturated with heat, they lose the ability to halt a vehicle, which can be somewhat disconcerting to the vehicle's operator.2） Disc BrakesDisc brakes are used on the front wheels of most cars and on all four wheels onmany cars. A disc rotor is attached to the wheel hub and rotates with the tire and wheel. When the driver applies the brakes, hydraulic pressure from the master cylinder is used to push friction linings against the rotor to stop it.In the disc brake rotor assembly, the rotor is usually made of cast iron. The hub may be manufactured as one piece with the rotor or in two parts. The rotor has a machined braking surface on each face. A splash shield, mounted to the steering knuckle, protects the rotor from road splash.A rotor may be solid or ventilated. Ventilated designs have cooling fins cast between the braking surfaces. This construction considerably increases the cooling area of the rotor casting. Also, when the wheel is in motion, the rotation of these fan-type fins in the rotor provides increased air circulation and more efficient cooling of the brake. Disc brakes do not fade even after rapid, hard brake applications because of the rapid cooling of the rotor.The hydraulic and friction components are housed in a caliper assembly. The caliper assembly straddles the outside diameter of the hub and rotor assembly. When the brakes are applied, the pressure of the pistons is exerted through the shoes in a 'clamping＇action on the rotor. Because equal opposed hydraulic pressures are applied to both faces of the rotor throughout application, no distortion of the rotor occurs, regardless of the severity or duration of application. There are many variations of caliper designs, but they can all be grouped into two main categories: moving and stationary caliper. The caliper is fixed in one position on the stationary design. In the moving design, the caliper moves in relation to the rotor.Most late-model cars use the moving caliper design. This design uses a single hydraulic piston and a caliper that can float or slide during application. Floating designs｀float＇or move on pins or bolts. In sliding designs, the caliper slides sideways on machined surfaces. Both designs work in basically the same way.In the single piston floating caliper, the single-piston caliper assembly is constructed from a single casting that contains one large piston bore in the inboard section of the casting. Inboard refers to the side of the casting nearest the center line of the car when the caliper is mounted. A fluid inlet hole and bleeder valve hole are machined into the inboard section of the caliper and connect directly to the piston bore.The caliper cylinder bore contains a piston and seal. The seal has a rectangular cross section. It is located in a groove that is machined in the cylinder bore. The sealfits around the outside diameter of the piston and provides a hydraulic seal between the piston and the cylinder wall. The rectangular seal provides automatic adjustment of clearance between the rotor and shoe and linings following each application. When the brakes are applied, the caliper seal is deflected by the hydraulic pressure and it inside diameter rides with the piston within the limits of its retention in the cylinder groove. When hydraulic pressure is released, the seal relaxes and returns to its original rectangular shape, retracting the piston into the cylinder enough to provide proper running clearance.As brake linings wear, piston travel tends to exceed the limit of deflection of the seal; the piston therefore slides in the seal to the precise extent necessary to compensate for lining wear.The top of the piston bore is machined to accept a sealing dust boot. The piston in many calipers is steel, precision ground, and nickel chrome plated, giving it a very hard and durable surface. Some manufacturers are using a plastic piston. This is much lighter than steel and provides for a much lighter brake system. The plastic piston insulates well and prevents heat from transferring to the brake fluid. Each caliper contains two shoe and lining assemblies. They are constructed of a stamped metal shoe with the lining riveted or bonded to the shoe and are mounted in the caliper on either side of the rotor. One shoe and lining assembly is called the inboard lining because it fits nearest to the center line of the car. The other is called the outboard shoe and lining assembly.The application and release of the brake pressure actually causes a very slight movement of the piston and caliper. Upon release of the braking effort, the piston and caliper merely relax into a released position. In the released position, the shoes do not retract very far from the rotor surfaces.As the brake lining wears, the piston moves out of the caliper bore and the caliper repositions itself on the mounting bolts an equal distance toward the car. This way, the caliper assembly maintains the inboard and outboard shoe and lining in the same relationship with the rotor surface throughout the full length of the lining.Sliding calipers are made to slide back and forth on the steering knuckle support to which it is mounted. There is a V shaped surface, sometimes called a rail, on the caliper that matches a similar surface on the steering knuckle support. These two mating surfaces allow the caliper to slide in and out. The internal components of the caliper are the same as those previously described.The stationary or fixed caliper has a hydraulic piston on each side of the rotor. Larger calipers may have two pistons on each side of the rotor. The inboard and outboard brake shoes are pushed against the rotor by their own pistons. The caliper is anchored solidly and does not move. The seals around the pistons work just like those already described. The main disadvantage of the stationary caliper is that it has more hydraulic components. This means they are more expensive and have more parts to wear out .2.Other Components in the Hydraulic System:1）Proportioning Valve or Equalizer ValveThese valves are mounted between the master cylinder and the rear wheels. They are designed to adjust the pressure between the front and rear brakes depending on how hard you are st opping. The shorter you stop, the more of the vehicle’s weight is transferred to the front wheels, in some cases, causing the rear to lift and the front to dive. These valves are designed to direct more pressure to the front and less pressure to the rear the harder you stop. This minimizes the chance of premature lockup at the rear wheels.2）Pressure Differential ValveThis valve is usually mounted just below the master cylinder and is responsible for turning the brake warning light on when it detects a malfunction. It measures the pressure from the two sections of the master cylinder and compares them. Since it is mounted ahead of the proportioning or equalizer valve, the two pressures it detects should be equal. If it detects a difference, it means that there is probably a brake fluid leak somewhere in the system.3）Combination ValveThe Combination valve (Figure) is simply a proportioning valve and a pressure differential valve that is combined into one unit.The parking brake (a．k．a．emergency brake ) system controls the rear brakes through a series of steel cables that are connected to either a hand lever or a foot pedal. The idea is that the system is fully mechanical and completely bypasses the hydraulic system so that the vehicle can be brought to a stop even if there is a total brake failure.On drum brakes, the cable pulls on a lever mounted in the rear brake and is directly connected to the brake shoes. This has the effect of bypassing the wheel cylinder and controlling the brakes directly.Disk brakes on the rear wheels add additional complication for parking brakesystems. There are two main designs for adding a mechanical parking brake to rear disk brakes. The first type uses the existing rear wheel caliper and adds a lever attached to a mechanical corkscrew device inside the caliper piston. When the parking brake cable pulls on the lever, this corkscrew device pushes the piston against the pads, thereby bypassing the hydraulic system, to stop the vehicle. This type of system is primarily used with single piston floating calipers, if the caliper is of the four piston fixed type, then that type of system can’t be used. The other system uses a complete mechanical drum brake unit mounted inside the rear rotor. The brake shoes on this system are connected to a lever that is pulled by the parking brake cable to activate the brakes. The brake “drum” is actually the inside part of the rear brake rotor.On cars with automatic transmissions, the parking brake is rarely used. This can cause a couple of problems. The biggest problem is that the brake cables tend to get corroded and eventually seize up causing the parking brake to become inoperative. By using the parking brake from time to time, the cables stay clean and functional. Another problem comes from the fact that the self adjusting mechanism on certain brake systems uses the parking brake actuation to adjust the brakes. If the parking brake is never used, then the brakes never get adjusted.The power brake booster (Figure) is mounted of the firewall directly behind the master cylinder and, along with the master cylinder, is directly connected with the brake pedal. Its purpose is to amplify the available foot pressure applied to the brake pedal so that the amount of foot pressure required to stop even the largest vehicle is minimal. Power for the booster comes from engine vacuum. The automobile engine produces vacuum as a by-product of normal operation and is freely available for use in powering accessories such as the power brake booster. Vacuum enters the booster through a check valve on the booster. The check valve is connected to the engine with a rubber hose and acts as a one-way valve that allows vacuum to enter the booster but dose not let it escape. The booster is an empty shell that is divided into two chambers by a rubber diaphragm. There is a valve in the diaphragm that remains open while foot is off the brake pedal so that vacuum is allowed to fill both chambers. When stepping on the brake pedal, the valve in the diaphragm closes, separating the two chambers and another valve opens to allow air in the chamber on the brake pedal side. This is what provides the power assist. Power boosters are very reliable and cause few problems of their own. However, other things cam contribute to a loss of power assist. In order to have power assist, the engine must be running. If the engine stalls or shutsoff while you are driving, you will have a small reserve of power assist for two or three pedal applications but, after that, the brakes will be extremely hard to apply and you must put as much pressure as you can to bring the vehicle to a stop.The last topic is the Anti-Lock Brakes (ABS). The most efficient braking pressure takes place just before each wheel lock up. When you slam on the brakes in a panic stop and the wheels lock up, causing a screeching sound and leaving strips of rubber on the pavement, you do not stop the vehicle nearly as short as it is capable of stopping. Also, while the wheels are locked up, you loose all steering control so that , if you have an opportunity to steer around the obstacle, you will not be able to do so. Another problem occurs during an extended skid is that you will burn a patch of rubber off the tire which causes a “flat spot” on the tread that will produce an annoying thumping sound as you drive.Anti-lock brake systems solve this lockup problem by rapidly pumping the brakes whenever the system detects a wheel that is locked up. In most cases, only the wheel that is locked will be pumped, while full braking pressure stays available to the other wheels. This effect allows you to stop in the shortest amount of time while maintaining full steering control even if one or more wheels are on ice. The system uses a computer to monitor the speed of each wheel. When it detects that one or more wheels have stopped or are turning much slower than the remaining wheels, the computer sends a signal to momentarily remove and reapply or pulse the pressure to the affected wheels to allow them to continue turning. This “pumping” of the brakes occurs at tem or more times a second, far faster then a human can pump the brakes manually. If you step on the brakes hard enough to engage the anti-lock system, you may feel a strong vibration in the brake pedal. This is a normal condition and indicates that the system is working; however, it can be disconcerting to some people who don’t expect it. If your vehicle has anti-lock brakes, read your owner’s manual to find out more about it.The system consists of am electronic control unit, a hydraulic actuator, and wheel speed sensors at each wheel. If the control unit detects a malfunction in the system, it will illuminate an ABS warming light on the dash to let you know that there is a problem. If there is a problem, the antilock system will not function but the brakes will otherwise function normally.3.Friction materialsBrake shoes and pads are constructed in a similar manner. The pad or shoe iscomposed of a metal backing plate and a friction lining. The lining is either bonded (glued) to the metal, or riveted. Generally, riveted linings provide superior performance, but good quality bonded linings are perfectly adequate.Friction materials will vary between manufacturers and type of pad and the material compound may be referred to as: asbestos, organic, semi-metallic, metallic. The difference between these compounds lies in the types and percentages of friction materials used, material binders and performance modifiers.Generally speaking, organic and non-metallic asbestos compound brakes are quiet, easy on rotors and provide good feel. But this comes at the expense of high temperature operation, so they may not be your best choice for heavy duty use or mountain driving. In most cases, these linings will wear somewhat faster than metallic compound pads, so you will usually replace them more often. But, when using these pads, rotors tend to last longer.Semi-metallic or metallic compound brake linings will vary in performance based on the metallic contents of the compound. Again, generally speaking, the higher the metallic content, the better the friction material will resist heat. This makes them more appropriate for heavy duty applications, but at the expense of braking performance before the pad reaches operating temperature. The first few applications on a cold morning may not give strong braking. Also, metallic and semi-metallic are more likely to squeal. In most cases, metallic compounds last longer than non-metallic pads, but they tend to cause more wear on the rotors. If you use metallic pads, expect to replace the rotors more often.When deciding what type of brake lining is right for you, keep in mind that today's modern cars have brake materials which are matched to the expected vehicle＇s performance capabilities. Changing the material from OEM specification could adversely affect brake feel or responsiveness. Before changing the brake materials, talk to your dealer or parts supplier to help decide what is most appropriate for your application. Remember that heavy use applications such as towing, stop and go driving, driving down mountain roads, and racing may require a change to a higher performance material.Some more exotic materials are also used in brake linings, among which are Kevlar and carbon compounds. These materials have the capability of extremely good performance for towing, mountain driving or racing. Wear characteristics can be similar to either the metallic or the non-metallic linings, depending on the product youbuy. Most race applications tend to wear like metallic linings, while many of the street applications are more like the non-metallic制动系统1. 刹车：鼓与盘制动技术，就像悬浮技术和燃料系统技术，已走过了漫长的道路1）鼓式制动器早在后时代，手杠杆的汽车制动系统用鼓装在所有的四个车轮。
汽车专业英语全文翻译
汽车工程专业英语全文翻译一当今的汽车一般都由15000多个分散、独立且相互配合的零部件组成..这些零部件主要分为四类：车身、发动机、底盘和电气设备..Body：车身Engine：发动机Brakes：制动器Power train：传动系Steering：转向系Electrical：电器及电子设备Suspension：悬架Layout of a passenger car：乘用车总布置Layout of a commercial vehicle：商用车总布置1.1 车身汽车车身是由车窗、车门、发动机罩和行李箱盖焊接在金属板外壳发动机发动机作为动力装置..最常见的发动机气缸的排列方式称为发动机配置..直列式发动机的汽缸呈一列布置..这个设计创造了一个简单的发动机缸体铸造..在车辆应用中;汽缸数一般是2-6缸;汽缸中心线与水平面垂直..当汽缸数增多时;发动机尺寸和曲轴就成为一个问题..解决这个问题的办法就是采用V形汽缸呈两列布置;且两列气缸之间夹角为V形发动机..这个设计使发动机尺寸和曲轴都变得更短且更坚硬.. 前置发动机纵向安装;既可前轮驱动也可后轮驱动..后置发动机是将发动机安装在后轮后面..发动机可横置或纵置;一般情况下为后轮驱动..1.4 电气系统电气系统为起动机、点火系统、照明灯具、取暖器提供电能..该电平由一个充电电路维护..1.4.1 充电充电系统为所有汽车电子元件提供电能..充电系统主要包括：蓄电池;交流发电机;电压调节器;即通常是交流发电机上不可或缺的;充电警告或指示灯和金属丝连成一个完整电路..蓄电池为起动提供电能;然后发动机工作;交流发电机就为所有的电子元件提供电能..同时也给蓄电池充电即用来使发动机起动..电压调节器有过充保护作用..1.4.2 起动起动系统包括：蓄电池、电缆、起动机、飞轮和换向器..起动时;有两个动作同时运行;该起动机齿轮与飞轮齿圈啮合;并起动电机;然后运行传输到发动机曲轴..起动机电机将起动机安装在发动机缸体上并由电池供电..1.4.3 点火一个基本的点火系统包括：蓄电池、低压电缆、点火线圈、线圈高压电缆、火花塞电缆和火花塞..点火系统提供高强度火花使火花塞点燃燃料室里的液体燃料..火花必须在适当的时候提供;并达到能够使燃料点燃的能量要求..这些能量从蓄电池和交流发电机获得;点火线圈使电压增高..该系统有两个电路;主电路或低压电路点燃火花;次电路或高压电路产生高压并将其分配到火花塞上.. 复习题1. 列出汽车有那几部分组成..2. 根据车身外形车辆常见类型是什么3. 向下移动的冰锥增加汽缸容积和新鲜的通过进气阀开启的空气燃料混合..2．压缩行程向上移动的活塞减少了汽缸内体积和压缩的空气燃料混合物..不久之前;香港贸易发展局是达成共识;火花塞点燃压缩空气燃料的混合物;从而启动了燃烧过程..更高的压缩比意味着更好的燃油利用率..压缩的程度受制于敲限制..3.做功行程火花点火后在火花塞点燃了压缩空气燃料的混合物;作为混合的结果温度升高..在汽缸增加;迫使活塞向下的压力..活塞转让的权力;通过连杆曲轴..4.排气行程向上移动的活塞燃烧排出的气体废气通过公开排气阀..在四冲程过完成后又周期重复..这台发动机有数以百计的其它部分..发动机的主要部件是发动机缸体;发动机头;活塞;连杆;曲轴和阀门..其他部分一起营造系统..这些系统是燃油系统;进气系统;点火系统;冷却系统;润滑系统和排气图2 - 2..这些系统都有一定的作用..这些系统将在后面详细讨论..发动机缸体是发动机的基本框架..所有其他发动机零件要么在其中的位置或固定它..其所持有的气瓶;水套和油画廊图2 - 4..发动机缸体还持有曲轴;那拴到块的底部..还装在凸轮轴块;除却架空凸轮OHC发动机..在大多数汽车;这个部件是由灰铸铁或者一种合金混合物灰铁和其它金属如镍或铬..发动机缸体是铸件..有些气缸体;特别是在小汽车里的那些;都是由铝做成的..这种金属比铁轻得多;然而;铁的耐磨性比铝好..因此;在大多数铝制发动机的气缸活塞;连杆和曲轴2.3.1 曲柄机构和能量活塞由曲柄机构和气缸;连杆组成..这些部件通过气体能量推动;从而引起这些部件产生惯性力..气能产生的力可以再细分为垂直于竖直平面的力Fn;且作用于汽缸壁;和一个推动连杆的力Fs;这个连杆的力;从而引起切向力Ft并作用于曲柄机构;这些能量要求在一起产生扭转和法向力Fr..这气体作用力分为作用角α;支点于连杆的作用角β;和压缩比入:连杆作用力: Fs=Fg/cosβ侧向力 : Fn=Fgtanβ法向力 : Fr=Fgcosα+β/ cosβ切向力 : Ft=Fg sinα+β/ cosβ所以的这些关系代表了一种方法计算各部件的振动.活塞是四个运动周期中一个重要部分;很多活塞都是从铝中提炼出来研制而成的.活塞;通过连杆传递能量来压缩点燃混合气体.这些能力转化为曲柄的动能.这样;圆形的钢圈装入汽缸;用活塞环来密封整个燃烧室.这个称为活塞环..这些用来放活塞环的称为凹槽..一个活塞销放在中间通过一个小孔固定..活塞销的作用是固定活塞于连杆之间的连接;对活塞销起作用的是活塞销凸台..活塞本身;它的环和活塞销一起称为活塞总成..1活塞为了抵抗高温的燃烧室;活塞必须非常坚固;但是也必须轻便;因为它是在气缸内高速运转而上下运动的;活塞内是空的;在顶部是厚的用来传递高温高压的气体动力;底部温度较低所以做成薄的..顶部是活塞头或活塞顶;薄部分是裙部;两节之间的凹槽称为环带..活塞顶可以是平的;凹的;圆顶的或是隐蔽的;在柴油机的燃烧可能形成完全或部分活塞冠;依靠这种方法喷射..所以活塞采用不同的形状..2..活塞环如图2-9所示;活塞环装进接近活塞顶部的环槽..简单来说;活塞环是薄的;是圆形的金属片;适合槽活塞顶部的..现在的发动机;每个活塞有三个活塞环;老式的发动机有四个甚至五个..活塞环装在活塞内表面的凹槽内..活塞环的外表面紧靠着汽缸壁活塞环提供了活塞环于汽缸壁之间的密封;也就是说;只有活塞环接触汽缸壁..顶头两个活塞环是防止气体从汽缸壁漏出的;称为压缩环..最底下的一个是防止汽油飞溅到缸桶而从间隙进入到燃烧室;所以称为油环..表面镀铬的铸铁压缩环一般用于汽车的发动机..镀铬的活塞环提供了光滑;耐磨的表面..在做功行程;燃烧室对压缩环的压力是非常大的..原因是他们朝汽缸壁方向挤开;一些高压的气体进入到活塞环;这样使得活塞环表面充分接触到汽缸壁;燃烧的气体压力使得活塞环底部紧紧地压住活塞凹槽;然而;越高的燃烧的气体压力更加紧紧地把活塞环表面和汽缸壁密封住.. 3..活塞销活塞销是用来连接活塞于连杆的..活塞销装入销孔;装入连杆最顶头的小孔..连杆的顶部应远小于连杆的尾部才能装进曲柄轴颈..小的底部装进活塞的内底部..活塞销通过一边装入活塞销;通过小的连杆一端;然后通过活塞的另一边..这使得连杆稳固地在活塞中间适当的位置..活塞销是是空心的且是高强度的钢制成的..很多销的镀铬的使得更加耐磨..连杆是高强度的钢铸造的;它通过曲柄轴颈传递力和运动从活塞到曲柄销..连杆小的一头是连接活塞销的..轴瓦是用软金属制成的;比如青铜;用来这样合成的..下级的连杆装进曲柄轴颈..这称为大头..这个轴承;是钢背的铅或者是锡壳制成的..这些是一样被用作主要轴承..大端的分离切口往往是单个的;所以它足够小可以从燃烧室中取出.. 连杆由合金钢铸成..曲轴如图2-10所示;连同连杆通过旋转而带动活塞往复运动从而带动汽车行驶..它是由碳钢和低比例的镍合成的主要的曲轴轴颈装进汽缸;大端匹配连杆..在曲轴的后端附加有飞轮;在曲轴的前端有驱动轮对应的正时齿轮;风扇;冷却水和发电机..曲轴的摆幅;i;e;是主要的轴颈和大端中心之间的距离..控制冲程的幅度;冲程是双次进行的;摆动的幅度是活塞从TDC到BDC的距离;反之亦然..单缸的发动机每两次曲轴循环只能提供单一的能量脉冲..能量只能提供四分之一的时间..当超过一个汽缸时它能从曲轴获得流动性的能量..额外的能量被均匀地隔开遍及两个转数或四冲程的一个周期..四缸的一般用于汽车..为了保持曲轴的平衡设置第一和第四的活塞是在TDC..第二和第三的活塞是在BDC每个冲程的间隔是180°;图标的序列显示了各个缸的点火顺序;点火顺序是1-3-4-2;但是这个顺序可以改变为1-2-4-3;如果安装了另外的凸轮轴.. 注意到第四个活塞总是伴随着第一活塞进行的..当第四活塞进气阀完全打开时;第一缸的活塞完全关闭;这是用来调节气门间隙的..表格飞轮有碳钢制成;装在曲轴的后端..同时带动曲轴旋转和离合器..同时传送给变速器;和启动齿圈包围着在四个冲程当中只有一个冲程是做功的所以飞轮只有在这个时间带动曲轴;发动机在这几个不做功的冲程转动..平衡器和减震器是用来保持发动机曲轴正常缓冲的..比如每个燃烧室燃烧;它能加快曲轴旋转..轴的惯性它稍稍随后;这样在曲轴上起扭转作用..连续扭转震动引起的频率不同于发动机的转速和发动机缸数..减震器减少他们的振动..减震器主要由轮毂和惯性环组成..惯性环是结合轮毂通过弹性插入的..惯性环转动是和曲轴密切相关的在燃烧室内;然而抑制其扭转;并通过曲轴控制犯低级转速..一些减震器是由两个惯性环和而且是不同的尺寸从而更好地控制其振动..使用了一段时间后;弹性体会恶化或连接件可以不要..致使减震器失效或是引起自身振动.. 损坏的必须得替换下来..减震器的设计要结合轮毂的密封轴颈..在轮毂里密封凹槽;造成石油泄漏..袖套修理可以恢复减震器如果是在良好的条件下..轮毂在一定条件下可以维修来调节衬套..2.6.1 汽油汽油是从原油中提炼石油..汽油是高度易燃的;这意味着它容易在空气容易燃烧..汽油容易蒸发..这种特性被称为波动;是重要的..但是;它不能太容易挥发;否则将转向油箱内的蒸汽..管内的燃料;燃料蒸气可能阻止液体汽油流..这就是所谓的蒸气锁..在燃料蒸气锁普遍在暴露于高温线泵的进口侧..汽油的燃烧;随其质量和添加剂比例混合的..汽油的燃烧方式在室燃烧是很重要的.增加燃烧室中的燃料混合物点火前的压力;有助于提高发动机功率..这是通过压缩到一个较小的燃料混合物体积..高压缩比;不仅有利于推力;而且也给更多的有效的动力..但更进一步的压缩比起来;敲倾向增加..辛烷值是对汽油的抗爆性的质量或在燃烧过程中能够抵抗爆炸的认定..有时被称为爆震敲质量或能力抵御爆炸..爆轰;有时也被称为敲门;作为燃料的燃烧空气的混合物;由于温度过高;在燃烧室内的压力条件的最后一个部分失控爆炸的定义..由于爆炸产生的压力波冲击;因此产生敲缸声;燃料燃烧和空气的混合物的扩张;导致丧失权力;局部温度过高;如果足够严重;引擎损害..有两种常用的汽油辛烷值测定的的方法马达法和研究方法..两者都使用的实验室相同的类型单缸发动机来做实验;这是一个头部和一个变量来表示敲缸爆震强度装置..作为燃料使用;发动机压缩比和空气燃料混合料试验样品进行了调整;试验出爆震强度..两个主要标准参考燃料;正庚烷和异辛烷;任意分配0和10辛烷值;然后分别是混合产生测试样品相同的爆震强度..因此百分比异辛烷的混合被认为是测试样品辛烷值;因此;如果相应的参考配方是由15％正庚烷和85％异辛烷;测试样品的额定电机向上或85研究法辛烷值;依据测试的一种方法..2.6.2完全燃烧汽油;是在理想条件下汽油在混合气中完全燃烧汽油所需要空气和汽油是15比1..这意味着1公斤汽油混合15公斤空气..汽油完全燃烧所需的空气被称为化学正确的混合物.. 15:1的比例适用于汽油;其他燃料有不同的比率.为了表示更实际;空气燃料混合物提供给空气燃料比14.7:1气缸偏离理论上完全燃烧所需;多余的空气因子R已被选定引擎：=空气质量提供/理论要求R为1 空气质量提供相应数额的理论的必要..<“1 空气或缺乏丰富的混合物..增加电力的射程R = 0.85 0.95输出结果..> 1.3 该混合物是如此精简的点火更长发生..精益失火超限.. = 0.95 0.85 火花点火发动机开发在5％ 15％空气不足的最大功率.. = 1.1 1.2 发生在最大的燃油经济性高达20％左右的过剩空气..为R≈1.0 这种过剩空气系数允许与化学计量比空转..= 0.85 0.75 良好的转换发生15％ 25％的空气不足..转型是指从一个给定的负载范围在实践中;过剩空气因素的R = 0.9 1.1已被证明是最实用的..在一定的操作条件下;燃料需求不同的混合模式于基本注入燃料的数量大于干预必需的. 冷启动在冷启动时;空气燃料混合物的发动机制定的加浓了..这是由于在起动速度低如果混合物燃油与空气粒子流动速度;并以最小的燃油蒸发和汽缸壁和进气口;在低温下润湿燃料..为了弥补这些现象;从而促进ID的冷发动机;注入更多的燃料才更容易起动..1．后启动阶段在低温起动后;必须加浓的一段短时期的混合物;以补偿较浠混合气的形成和摄入量与燃料缸..此外;在高扭矩;为更好的油门响应更加丰富的混合物时;加速从闲置的结果..2．热机预热阶段遵循冷启动阶段..该发动机的燃料需要;因为凝结一些仍然在寒冷的汽缸壁的热身阶段额外的燃料..在低温时;混合物的形成是由于较浓的大型燃料液滴的加入;由于与拟定的发动机在空气中混合燃料效率下降..其结果是;在进气阀门和进气歧管;只有在较高温度下燃油蒸发浓缩.. 上述因素均随温度降低必要的加浓的混合物.3．加速度如果油门突然被打开;空气燃料混合物瞬间倾斜过;以及混合浓缩短期在部分负荷运行;实现最大的燃油经济性和排放值是观察的关键因素.. 5．全负荷该引擎提供了在满负荷最大功率;当空气燃料混合比;必须加以丰富;在部分负荷..这种丰富依赖于发动机转速和提供最大的在整个发动机转速范围内尽可能的扭矩..这也确保在满负荷运行最佳燃油经济性的数字..6．怠速除了发动机的效率;发动机怠速主要决定于闲置的燃料消耗;在发动机冷高摩阻力;必须通过提高空气燃油混合输入克服..为了实现平稳运行在空闲;空闲速度控制怠速提高..这也导致了更快速热身的发动机..闭环闲置速度控制功能可以防止怠速过高..该混合物的数量相对应维持在有关的负载如冷发动机;并增加摩擦怠速所需要的数量..它还允许一个没有长期闲置的调整不断废气排放值..闭环闲置速度控制还部分地弥补在发动机老化带来的变化;并确保稳定的发动机整个使用寿命空转..7．空载减速时切断燃油降低燃油消耗不仅是长下坡运行和制动过程中;而且在城市交通..由于没有燃料完全燃烧;减少废气排放..8．发动机限速当发动机转速达到预设;教统会抑制燃油喷射脉冲..9..的空气燃料混合物在高海拔适应在高海拔地区的空气密度低就必须更精简的空气燃料混合物..在高海拔地区;由于较低的空气密度;容积流量的空气流量传感器对应一个较低的空气质量流量测量..这个错误可以弥补纠正的燃料数量..过度富集是可以避免的;因此;过多的燃料消耗..正如图2 - 20所示;燃料系统有一个油箱;油管;燃油泵;燃油滤清器和化油器..这零部件商店汽油;并提供给需要的化油器..简而言之;油箱储存汽油..行携带的燃料从油箱的燃料化油器..移动汽油燃油泵从油箱的燃料;并通过线化油器..燃料过滤器除去杂质的汽油..然后;化油器发送燃料的空气和汽油的混合物 - 进入燃烧室..1..燃油泵大多数车今天使用一个机械式燃油泵..这种燃料泵出了汽油;并通过油管向化油器或喷射系统..在大多数汽车;泵安装在发动机缸体..有些汽车电动燃油泵有一个..该泵安装在皮卡与燃料和燃料轨;发送单元油箱..对机械燃油泵操作取决于对凸轮轴叶..作者：爱在旋转移动泵摇臂..泵内;可以灵活的隔膜通过膜片弹簧摇臂;拉杆和链接..如图所示;燃油泵也有一个入口和燃料出口..由于凸轮轴上的旋转叶;横膈膜上下移动内部的引擎..隔膜的吸向下运动从进入泵油箱..隔膜向上运动推到了化油器;从泵的燃料..2..化油器化油器提供燃料比例的空气量流经喉管..当你在加速器踏板时;扩大开放节流阀吸引更多的空气通过化油器..化油器提供这取决于许多因素更丰富或更精简的混合物：发动机转速;负荷;温度;节气门位置..为了满足复杂的要求;一化油器是一个非常复杂的设备与许多内部通道及零部件.1喉管汽车化油器的设计是由喉管..喉管简直是气道狭窄的部分..空气通过化油器的喉咙;因为它移动的速度通过这个狭窄通道的旅行..通过建立合资企业增加的空气速度在喷嘴打开一个低压区..推动在一个大气压下水库内燃料的化油器浮子室称为..燃料是强行通过一根管子到空气流..2浮子室浮子室是一个储存和供应燃料的化油器水库..由于发动机使用的燃料;它会自动浮子室补充..浮动室内乐作品在同一作为一个抽水马桶水箱控股的基本原则..阿浮有赖于在水库燃料的顶部..作为燃料使用时;浮球液位下降..当浮动滴;一针阀打开..开放式针形阀允许从燃料的燃料泵入化油器的浮子室流..当商会是满了;针形阀是向上推;并关闭燃油进口..3测量燃油浮子室之间的压差和造成的燃料流..然而;为了维持适当的空气燃料比;化油器必须仅提供适量的燃料..为此;主放电管有一个小孔称为喷射或主射流..这允许燃料进入气流..在大多数情况下;这个小口子浮子室是在主放油管的末端..在那里;它的体积小燃油流量限制..4需要冷启动安排切断阀通过一个手段扼杀供气提供了丰富的混合物约8:1;并提供了一个轻松的粒子蒸发足够的引擎..5慢速贯穿化油器的空气量过小的时候;发动机只运行缓慢产生非常小的扼流圈抑郁症..这意味着太少将提供燃料和发动机将停止..缓慢运行的系统已经在这个区域里存在着抑郁症的高当发动机空转的电源插座..调节螺钉控制系统运行缓慢;一个螺丝设置空转速度运行缓慢等使混合物是让发动机转速平稳.. 6油门机制机制的油门控制空气燃料混合物流动..油门有几个;包括油门轴和节流板的一部分..通过打开和关闭;节气门控制的空气进入发动机燃料混合物流动..在诸如开放更多的空气流动;少的板关闭的气流..这些变化也气流控制汽油流..增加气流意味着更大的压力下降;从而更多的燃料流..气流减少意味着减少压降和流量较少的燃料..该议案的节流轴转动油门板..油门轴电缆连接到油门;反过来;连接到车内的油门踏板..司机控制空气燃料混合物踏板流动..2.6.5 莫特郎尼克点火和燃油喷射系统化油器将准确的空气燃料混合气发送到发动机..然而;并非所有的汽车都有化油器..许多现代汽车是用燃油喷射系统图2 - 22..燃油喷射系统与化油器式有许多优势..例如;它们能提供更多的精确控制..它们能够更好地匹配空燃比在不断变化的发动机状态..它们还提供更好的经济性和排放控制..此外;燃油喷射系统不需要化油器多余的那部分..该系统是一个莫特郎尼克发动机管理系统;包括控制单元ECU;它执行至少两个基本功能点火和喷油;但可能包含其他子系统需要改进的发动机控制1..测量值的检测气缸内的燃烧过程不仅受混合气和空气燃料比的影响;而且还受点火提前点火和点火火花的能源影响..一个优化的引擎控制;因此必须控制在整个喷射时刻的空气燃料比R A即喷入的燃油量;以及点火提前角α和持续角B..影响燃烧过程中的主要参数检测为测量值和一起处理瞬间发动机运行工况点火和喷射的最佳时机的计算..2..工作变量/传感器发动机转速和负荷是主要的工作变量..由于特定的点火提前角和精确的喷射时间对应于每个发动机的转速/负载地图点;重要的是所有的变量;其中涉及到同一个点都在相同的速度/负载面积计算..这不仅是可能的;如果点火提前和喷射时间以同样的速度和负载值发动机转速检测只有一次使用相同的传感器计算..这就避免了统计误差;可导致不同的负载传感器设备公差;例如;..而一个略有杆负荷范围不同的分配限制敲到发动机爆震的易感性增加..清除点火时间角和注射时间分配是由莫特郎尼克系统提供动力;即使在发动机运行条件下;3..莫特郎尼克系统该莫特郎尼克系统包括一系列子系统;两个基本子系统点火和喷油..综合后的系统更加灵活;可实现比相应的各个系统的功能更多..莫特郎尼克系统的重要特点是其作为一个最子功能所需的大量可自由编程实现地图..废气再循环EGR的功能至今尚未在欧洲使用;因此提供一种替代系统的唯一..控制系统的lambda只能算是今天;如果配合使用为减少尾统开环控制功能以及一个扩展的系统与闭环功能结合敲和lambda控制在管理系统气。
汽车制动系统中英文对照外文翻译文献
汽车制动系统中英文对照外文翻译文献(文档含英文原文和中文翻译)Brake systemsWe all know that pushing down on the brake pedal slows a car to a stop. But how does this happen? How does your car transmit the force from your leg to its wheels? How does it multiply the force so that it is enough to stop something as big as a car?Brake Image GalleryLayout of typical brake system. See more brake images.When you depress your brake pedal, your car transmits the force from your foot to its brakes through a fluid. Since the actual brakes require a much greater force than you could apply with your leg, your car must also multiply the force of your foot. It does this in two ways:∙Mechanical advantage (leverage)∙Hydraulic force multiplicationThe brakes transmit the force to the tires using friction, and the tires transmit that force to the road using friction also. Before we begin our discussion on the components of the brake system, we'll cover these three principles:∙Leverage∙Hydraulics∙FrictionLeverage and HydraulicsIn the figure below, a force F is being applied to the left end of the lever. The left end of the lever is twice as long (2X) as the right end (X). Therefore, on the right end of the lever a force of 2F is available, but it acts through half of the distance (Y) that the left end moves (2Y). Changing the relative lengths of the left and right ends of the lever changes the multipliers.The pedal is designed in such a way that it can multiply the force from yourleg several times before any force is even transmitted to the brake fluid.The basic idea behind any hydraulic system is very simple: Force applied at one point is transmitted to another point using an incompressible fluid, almost always an oil of some sort. Most brake systems also multiply the force in the process. Here you can see the simplest possible hydraulic system:Your browser does not support JavaScript or it is disabled.Simple hydraulic systemIn the figure above, two pistons (shown in red) are fit into two glass cylinders filled with oil (shown in light blue) and connected to one another with an oil-filled pipe. If youapply a downward force to one piston (the left one, in this drawing), then the force is transmitted to the second piston through the oil in the pipe. Since oil is incompressible, the efficiency is very good -- almost all of the applied force appears at the second piston. The great thing about hydraulic systems is that the pipe connecting the two cylinders can be any length and shape, allowing it to snake through all sorts of things separating the twopistons. The pipe can also fork, so that one master cylinder can drive more than one slave cylinder if desired, as shown in here:Your browser does not support JavaScript or it is disabled.Master cylinder with two slavesThe other neat thing about a hydraulic system is that it makes force multiplication (or division) fairly easy. If you have read How a Block and Tackle Works or How Gear Ratios Work, then you know that trading force for distance is very common in mechanical systems. In a hydraulic system, all you have to do is change the size of one piston and cylinder relative to the other, as shown here:Your browser does not support JavaScript or it is disabled.Hydraulic multiplicationTo determine the multiplication factor in the figure above, start by looking at the size of the pistons. Assume that the piston on the left is 2 inches (5.08 cm) in diameter (1-inch / 2.54 cm radius), while the piston on the right is 6 inches (15.24 cm) in diameter (3-inch / 7.62 cm radius). The area of the two pistons is Pi * r2. The area of the left piston is therefore 3.14, while the area of the piston on the right is 28.26. The piston on the right is nine times larger than the piston on the left. This means that any force applied to theleft-hand piston will come out nine times greater on the right-hand piston. So, if you apply a 100-pound downward force to the left piston, a 900-pound upward force will appear on the right. The only catch is that you will have to depress the left piston 9 inches (22.86 cm) to raise the right piston 1 inch (2.54 cm).A Simple Brake SystemBefore we get into all the parts of an actual car brake system, let's look at a simplified system:Your browser does not support JavaScript or it is disabled.A simple brake systemYou can see that the distance from the pedal to the pivot is four times the distance from the cylinder to the pivot, so the force at the pedal will be increased by a factor of four before it is transmitted to the cylinder.You can also see that the diameter of the brake cylinder is three times the diameter of the pedal cylinder. This further multiplies the force by nine. All together, this system increases the force of your foot by a factor of 36. If you put 10 pounds of force on the pedal, 360 pounds (162 kg) will be generated at the wheel squeezing the brake pads.There are a couple of problems with this simple system. What if we have a leak? If it is a slow leak, eventually there will not be enough fluid left to fill the brake cylinder, and the brakes will not function. If it is a major leak, then the first time you apply the brakes all of the fluid will squirt out the leak and you will have complete brake failure.Drum brakes work on the same principle as disc brakes: Shoes press against a spinning surface. In this system, that surface is called a drum.Figure 1. Location of drum brakes. See more drum brakepictures.Many cars have drum brakes on the rear wheels and disc brakes on the front. Drum brakes have more parts than disc brakes and are harder to service, but they are less expensive to manufacture, and they easily incorporate an emergency brake mechanism.In this edition of HowStuffWorks, we will learn exactly how a drum brake system works, examine the emergency brake setup and find out what kind of servicing drum brakes need.Figure 2. Drum brake with drum in placeFigure 3. Drum brake without drum in placeLet's start with the basics.The Drum BrakeThe drum brake may look complicated, and it can be pretty intimidating when you open one up. Let's break it down and explain what each piece does.Figure 4. Parts of a drum brakeLike the disc brake, the drum brake has two brake shoes and a piston. But the drum brake also has an adjuster mechanism, an emergency brake mechanism and lots of springs.First, the basics: Figure 5 shows only the parts that provide stopping power.Your browser does not support JavaScript or it is disabled.Figure 5. Drum brake in operationWhen you hit the brake pedal, the piston pushes the brake shoes against the drum. That's pretty straightforward, but why do we need all of those springs?This is where it gets a little more complicated. Many drum brakes are self-actuating. Figure 5 shows that as the brake shoes contact the drum, there is a kind of wedging action, which has the effect of pressing the shoes into the drum with more force.The extra braking force provided by the wedging action allows drum brakes to use a smaller piston than disc brakes. But, because of the wedging action, the shoes must be pulled away from the drum when the brakes are released. This is the reason for some of the springs. Other springs help hold the brake shoes in place and return the adjuster arm after it actuates.Brake AdjusterFor the drum brakes to function correctly, the brake shoes must remain close to the drum without touching it. If they get too far away from the drum (as the shoes wear down, for instance), the piston will require more fluid to travel that distance, and your brake pedal will sink closer to the floor when you apply the brakes. This is why most drum brakes have an automatic adjuster.Figure 6. Adjuster mechanismNow let's add in the parts of the adjuster mechanism. The adjuster uses theself-actuation principle we discussed above.Your browser does not support JavaScript or it is disabled.Figure 7. Drum brake adjuster in operationIn Figure 7, you can see that as the pad wears down, more space will form between the shoe and the drum. Each time the car stops while in reverse, the shoe is pulled tight against the drum. When the gap gets big enough, the adjusting lever rocks enough to advance the adjuster gear by one tooth. The adjuster has threads on it, like a bolt, so that it unscrews a little bit when it turns, lengthening to fill in the gap. When the brake shoes wear a little more, the adjuster can advance again, so it always keeps the shoes close to the drum.Some cars have an adjuster that is actuated when the emergency brake is applied. This type of adjuster can come out of adjustment if the emergency brake is not used forlong periods of time. So if you have this type of adjuster, you should apply your emergency brake at least once a week.ServicingThe most common service required for drum brakes is changing the brake shoes. Some drum brakes provide an inspection hole on the back side, where you can see how much material is left on the shoe. Brake shoes should be replaced when the friction material has worn down to within 1/32 inch (0.8 mm) of the rivets. If the friction material is bonded to the backing plate (no rivets), then the shoes should be replaced when they have only 1/16 inch (1.6 mm) of material left.Photo courtesy of a local AutoZone storeFigure 9. Brake shoeJust as in disc brakes, deep scores sometimes get worn into brake drums. If aworn-out brake shoe is used for too long, the rivets that hold the friction material to the backing can wear grooves into the drum. A badly scored drum can sometimes be repaired by refinishing. Where disc brakes have a minimum allowable thickness, drum brakes have a maximum allowable diameter. Since the contact surface is the inside of the drum, as you remove material from the drum brake the diameter gets bigger.Figure 10. Brake drum制动系统众所周知，踩下制动踏板可以使汽车减速至停止。
汽车制动系统英文翻译
湖北文理学院毕业设计(论文)英文翻译题目The transmission system of automobile汽车的传动系统专业班级姓名学号指导教师职称2015年3月26 日The transmission system of automobileIn the basic transmission system contains is responsible forpower connection device, change the power transmission mechanism, overcome the wheel sizeThe differential between the different speed, transmission shaft andthe coupling of the various agencies, after the four main device can make power transmission engine to the wheels.The 1 clutch: this group mechanism is arranged between the engine and manual transmission, will be responsible for the power transmission of the engine tothe manual gearbox.The gasoline engine vehicles in operation, the engine needs a continuous operation. But in order to meet the needs of automobile driving, the traffic must stop, shift and other functions, and therefore must be in the external linking points of the engine, to join a group of institutions, in order to transfer the demand interruption of power to the engine continued to operate, under thecircumstances, to get the vehicle static or to shift demand. This group of institutions, is the power connection device. Dynamic general in the vehicle can be seen on the connected device with a clutch and torque converter two.braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes, the driver commands a stopping force ten times as powerful 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.Clutch this group mechanism is arranged between the engine and manual transmission, will be responsible for the power transmission of the engine tothe manual gearbox. As shown in the figure, the flywheel mechanism and the output shaft of the engine is fixed together. Inthe flywheelshell, with a disc spring connecting plate, there is a friction disc and the gear box input shaft connection.When the clutch pedal is released, the pressure plate flywheel within the power ofusing spring,tightly press the friction plate, the pro cyclical phenomenon in noslippage between the two, the purpose of a connection, and the power of theengine can be through this mechanism, transfer to the gearbox, and complete the work of power transfer.friction plate and the flywheel has been unable to link, even if the engine runs continuously, pWhen the pedal is stepped, the agencies will provide spring pressure, make ower and will not transfer to the gearbox and the wheel, at this time, the driver can shiftspring peripheral tilt,pressure and friction plate from skin. At this time between the and parking such action, and not make the engine flameout.The 2 torque converter: this group of institutions is device between the engine and automatic transmission, can transfer the power of engine smoothly tothe automatic gearbox. Contains a set of clutch in the torque converter, in order to increase the transmission efficiency.When the continued development of the automobile industry, thegeneral consumers begin tocontrol the throttle, brake and clutch and othercomplex operation modes of the three pedal feel bored. Mechanicalengineers began thinking about how to use the mechanism to simplify the operation process. Torque converter is being imported automotive products in such a case, the achievements of the brand new feelings.Torque converter import, changed people driving habits! Torque converter to replace thetraditional mechanical clutch, is mounted between the engineand automatic transmission, can transfer the power of engine smoothly tothe automatic gearbox.From the map can clearly see, the difference between torque converter fromthe ways and clutch.In the torque converter, the left side is the engine power output shaft is directly connected with thepump wheel shell. In the torque converter on the left, a turbine, through the shaft and thetransmission system is located on the right side of the connection. There is no direct connectionbetween the guidewheel mechanism and turbine, both sealing in the torque converter shell, andthe torque converter inside is filled with a viscous liquid.When the engine runs at a low speed, the torque converter will do the samefor low speed operation, vane pump wheel can drive a viscous fluid torque converter, it makes the circulation flow. But because the speed is too low, theliquid for turbine applied force, is not enough to propel the vehicle, the vehicle canbe stationary, and can reach as clutch separation conditionWhen the throttle is stepped down, the engine speed upgrade, pumpwheel speed will besynchronized to upgrade, the flow rate of the liquid torque converter continues to increase, theturbine force continues to increase, when it exceeds the running resistance, the vehicle can move forward, power canbe transmitted to the transmission system and the wheel, achieve the purpose of power transmission.The car needs in the initial acceleration driving force is relatively large, the vehicle speed is low,while the engine is in high speed to output to the larger power.When the speed gradually accelerated, driving dynamics need cars has been gradually reduced,this time as long as the engine to reduce speed to reduce the power output, and can provideenough power for automobile. The speed of the carin the process from low to high, the speed of the engine is the transition from highto low, how to solve the contradiction phenomenon? Socalled "the transmission" can change between the engine and the wheel changing device of rotordifference therefore born.Gearbox as dependent on the operation of the different and "manual transmission" and "automatic gearbox" two systems, these two kindsof transmission way of working is not the same. In recent years, due to consumer demand and the progress of technology, automatic transmission car factory development called "manumatic" can be operated manually; in additionthe car factory is also a vehicle for developing high performance called "manual transmissionwith automatic operation function of sequential semi-automatic gearbox". F1 racing currentcomprehensive use "order type semi-automatic gearbox", so use this type manual transmissionvehicles were advertised fromF1 technology.1 manual transmission mechanism: commonly known as "manual transmission", to shift to manual operation mode.A clutch, manual gearbox twomain parts in the manual transmission system.Clutch: the engine is used to power to the transmission mechanism, the use of friction friction to transmit power. Clutch used in general models of only two pieces of friction plates, and the carand truck vehicles use more friction plate with clutch. Clutch and dry and wet two, wet clutch at present almost no longer be used in automotive top.Manual gearbox: manually operated gearbox to do shift action, the gear meshing manual gear boxinput shaft and the output shaft. After a plurality of groups of different number of teeth meshinggear collocation, can produce a varietyof deceleration rate. At presentManual transmissions are engagingmechanism using synchronous gear shift, make the operation more simple, shift smoothness better2 automatic transmission mechanism: commonly known as "automatic transmission", to change gears using oil pressure function. In order to makethe car operation becomes simple, and let not good at operating manual transmission drivers can also easily driving cars, so making a capable of automatic transmission shift becomes an important work, so the automobile engineers in 1940 developed the world's first automatic gearbox with. After driving a car stopped at the start, and the running process of acceleration and deceleration, the drivers do not need the shift action.Automatic transmission system of modern contains threemain fluid torque converter, automatic transmission, electronic controlsystem. Control procedures to join the manual shift in theelectroniccontrol system, became a manual gearbox with manual operation "".Fluid torque converter: between active and passive impeller impeller, the useof hydraulic oil aspower transmission medium. The power is transmitted to the output shaft from the input shaft tothe output shaft via the, power can be transmitted tothe automatic gearbox.Because the power of the hydraulic oil flow betweenthe active and passive impeller impeller will consume part of the. In order to reduce the power loss, joined the group as a real impeller makes the transfer efficiency of energy between active and passive impeller; and joined a group of clutchin liquid torque converter, and the active and passive impeller lock using a clutch in the properrunning condition, let no longer have the speed difference between the active and passiveimpeller. And improve the transmission efficiency of power.Automatic transmission: planetary gear set consists of a shift mechanism, the use of hydraulicdriven friction plate multi group, to control the planetary gear set of the action, to change thepower transmission path in the gear group, resulting in a variety of different reduction ratio.Electronic control system: the shift control of automatedmechanical transmission is in earlychange of pressure oil to decide when to do the shift action, even after many years of research and improvement, the shifting performance of mechanical automatic transmission is stillunsatisfactory. So the electronic type automatic gearbox coping out. In order to make the shifttiming more precise, and get more smooth shift quality, various car manufacturers have investeda lot of resources, do research on electronic control system of automatic transmission.Three, the differential after solving the problem of vehicle power transmission, automotive engineer and ran into another problem - turn. When the vehicle when turning, left and right two sides of the wheel will producedifferent rotating speed, thus driving the two side of the shaft from left to right, will have different speed, so the use of differential to solve the two left and right edges speed different problems.Turn, except must have the steering system of the auxiliary, also must make adjustments in thetransmission system. The reason is that, when the vehicleis cornering, path located on the inside of the wheels go short, a longer path is located outside the wheels go. At the same time through this path, the left and right sidesof the wheel speed is bound to face different problems. If there is not a special agency to deal with, will cause the vehicle have been not past difficulties in turn;evenif forced to turn in the past, will also have a serious problem of wheel wear. At this time, the differential is the transmission system of imported cars.From the figure we can see, the differential is composed ofmany gear group. When the row isabout the same, wheel speed, the innergear group did not happen as role, left and right wheelsin thesame axle operation. When a vehicle enters a curve, the speed difference between left and right wheels, by rotating the middle gear sets to absorb, so that it canbe smoothly curved.。
汽车制动系统英文翻译
湖北文理学院毕业设计(论文)英文翻译题目The transmission system of automobile汽车的传动系统专业班级姓名学号指导教师职称2015年3月26 日The transmission system of automobileIn the basic transmission system contains is responsible forpower connection device, change the power transmission mechanism, overcome the wheel sizeThe differential between the different speed, transmission shaft andthe coupling of the various agencies, after the four main device can make power transmission engine to the wheels.The 1 clutch: this group mechanism is arranged between the engine and manual transmission, will be responsible for the power transmission of the engine tothe manual gearbox.The gasoline engine vehicles in operation, the engine needs a continuous operation. But in order to meet the needs of automobile driving, the traffic must stop, shift and other functions, and therefore must be in the external linking points of the engine, to join a group of institutions, in order to transfer the demand interruption of power to the engine continued to operate, under thecircumstances, to get the vehicle static or to shift demand. This group of institutions, is the power connection device. Dynamic general in the vehicle can be seen on the connected device with a clutch and torque converter two.braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes, the driver commands a stopping force ten times as powerful 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.Clutch this group mechanism is arranged between the engine and manual transmission, will be responsible for the power transmission of the engine tothe manual gearbox. As shown in the figure, the flywheel mechanism and the output shaft of the engine is fixed together. Inthe flywheelshell, with a disc spring connecting plate, there is a friction disc and the gear box input shaft connection.When the clutch pedal is released, the pressure plate flywheel within the power ofusing spring,tightly press the friction plate, the pro cyclical phenomenon in noslippage between the two, the purpose of a connection, and the power of theengine can be through this mechanism, transfer to the gearbox, and complete the work of power transfer.friction plate and the flywheel has been unable to link, even if the engine runs continuously, pWhen the pedal is stepped, the agencies will provide spring pressure, make ower and will not transfer to the gearbox and the wheel, at this time, the driver can shiftspring peripheral tilt,pressure and friction plate from skin. At this time between the and parking such action, and not make the engine flameout.The 2 torque converter: this group of institutions is device between the engine and automatic transmission, can transfer the power of engine smoothly tothe automatic gearbox. Contains a set of clutch in the torque converter, in order to increase the transmission efficiency.When the continued development of the automobile industry, thegeneral consumers begin tocontrol the throttle, brake and clutch and othercomplex operation modes of the three pedal feel bored. Mechanicalengineers began thinking about how to use the mechanism to simplify the operation process. Torque converter is being imported automotive products in such a case, the achievements of the brand new feelings.Torque converter import, changed people driving habits! Torque converter to replace thetraditional mechanical clutch, is mounted between the engineand automatic transmission, can transfer the power of engine smoothly tothe automatic gearbox.From the map can clearly see, the difference between torque converter fromthe ways and clutch.In the torque converter, the left side is the engine power output shaft is directly connected with thepump wheel shell. In the torque converter on the left, a turbine, through the shaft and thetransmission system is located on the right side of the connection. There is no direct connectionbetween the guidewheel mechanism and turbine, both sealing in the torque converter shell, andthe torque converter inside is filled with a viscous liquid.When the engine runs at a low speed, the torque converter will do the samefor low speed operation, vane pump wheel can drive a viscous fluid torque converter, it makes the circulation flow. But because the speed is too low, theliquid for turbine applied force, is not enough to propel the vehicle, the vehicle canbe stationary, and can reach as clutch separation conditionWhen the throttle is stepped down, the engine speed upgrade, pumpwheel speed will besynchronized to upgrade, the flow rate of the liquid torque converter continues to increase, theturbine force continues to increase, when it exceeds the running resistance, the vehicle can move forward, power canbe transmitted to the transmission system and the wheel, achieve the purpose of power transmission.The car needs in the initial acceleration driving force is relatively large, the vehicle speed is low,while the engine is in high speed to output to the larger power.When the speed gradually accelerated, driving dynamics need cars has been gradually reduced,this time as long as the engine to reduce speed to reduce the power output, and can provideenough power for automobile. The speed of the carin the process from low to high, the speed of the engine is the transition from highto low, how to solve the contradiction phenomenon? Socalled "the transmission" can change between the engine and the wheel changing device of rotordifference therefore born.Gearbox as dependent on the operation of the different and "manual transmission" and "automatic gearbox" two systems, these two kindsof transmission way of working is not the same. In recent years, due to consumer demand and the progress of technology, automatic transmission car factory development called "manumatic" can be operated manually; in additionthe car factory is also a vehicle for developing high performance called "manual transmissionwith automatic operation function of sequential semi-automatic gearbox". F1 racing currentcomprehensive use "order type semi-automatic gearbox", so use this type manual transmissionvehicles were advertised fromF1 technology.1 manual transmission mechanism: commonly known as "manual transmission", to shift to manual operation mode.A clutch, manual gearbox twomain parts in the manual transmission system.Clutch: the engine is used to power to the transmission mechanism, the use of friction friction to transmit power. Clutch used in general models of only two pieces of friction plates, and the carand truck vehicles use more friction plate with clutch. Clutch and dry and wet two, wet clutch at present almost no longer be used in automotive top.Manual gearbox: manually operated gearbox to do shift action, the gear meshing manual gear boxinput shaft and the output shaft. After a plurality of groups of different number of teeth meshinggear collocation, can produce a varietyof deceleration rate. At presentManual transmissions are engagingmechanism using synchronous gear shift, make the operation more simple, shift smoothness better2 automatic transmission mechanism: commonly known as "automatic transmission", to change gears using oil pressure function. In order to makethe car operation becomes simple, and let not good at operating manual transmission drivers can also easily driving cars, so making a capable of automatic transmission shift becomes an important work, so the automobile engineers in 1940 developed the world's first automatic gearbox with. After driving a car stopped at the start, and the running process of acceleration and deceleration, the drivers do not need the shift action.Automatic transmission system of modern contains threemain fluid torque converter, automatic transmission, electronic controlsystem. Control procedures to join the manual shift in theelectroniccontrol system, became a manual gearbox with manual operation "".Fluid torque converter: between active and passive impeller impeller, the useof hydraulic oil aspower transmission medium. The power is transmitted to the output shaft from the input shaft tothe output shaft via the, power can be transmitted tothe automatic gearbox.Because the power of the hydraulic oil flow betweenthe active and passive impeller impeller will consume part of the. In order to reduce the power loss, joined the group as a real impeller makes the transfer efficiency of energy between active and passive impeller; and joined a group of clutchin liquid torque converter, and the active and passive impeller lock using a clutch in the properrunning condition, let no longer have the speed difference between the active and passiveimpeller. And improve the transmission efficiency of power.Automatic transmission: planetary gear set consists of a shift mechanism, the use of hydraulicdriven friction plate multi group, to control the planetary gear set of the action, to change thepower transmission path in the gear group, resulting in a variety of different reduction ratio.Electronic control system: the shift control of automatedmechanical transmission is in earlychange of pressure oil to decide when to do the shift action, even after many years of research and improvement, the shifting performance of mechanical automatic transmission is stillunsatisfactory. So the electronic type automatic gearbox coping out. In order to make the shifttiming more precise, and get more smooth shift quality, various car manufacturers have investeda lot of resources, do research on electronic control system of automatic transmission.Three, the differential after solving the problem of vehicle power transmission, automotive engineer and ran into another problem - turn. When the vehicle when turning, left and right two sides of the wheel will producedifferent rotating speed, thus driving the two side of the shaft from left to right, will have different speed, so the use of differential to solve the two left and right edges speed different problems.Turn, except must have the steering system of the auxiliary, also must make adjustments in thetransmission system. The reason is that, when the vehicleis cornering, path located on the inside of the wheels go short, a longer path is located outside the wheels go. At the same time through this path, the left and right sidesof the wheel speed is bound to face different problems. If there is not a special agency to deal with, will cause the vehicle have been not past difficulties in turn;evenif forced to turn in the past, will also have a serious problem of wheel wear. At this time, the differential is the transmission system of imported cars.From the figure we can see, the differential is composed ofmany gear group. When the row isabout the same, wheel speed, the innergear group did not happen as role, left and right wheelsin thesame axle operation. When a vehicle enters a curve, the speed difference between left and right wheels, by rotating the middle gear sets to absorb, so that it canbe smoothly curved.。
汽车专业英语全文翻译
汽车工程专业英语全文翻译一当今的汽车一般都由15000 多个分散、独立且相互配合的零部件组成。
这些零部件主要分为四类：车身、发动机、底盘和电气设备。
Body：车身Engine：发动机Brakes：制动器Power train ：传动系Steering：转向系Electrical：电器及电子设备Suspension：悬架Layout of a passenger car：乘用车总布置Layout of a commercial vehicle ：商用车总布置1.1 车身汽车车身是由车窗、车门、发动机罩和行李箱盖焊接在金属板外壳发动机发动机作为动力装置。
最常见的发动机气缸的排列方式称为发动机配置。
直列式发动机的汽缸呈一列布置。
这个设计创造了一个简单的发动机缸体铸造。
在车辆应用中，汽缸数一般是2-6 缸，汽缸中心线与水平面垂直。
当汽缸数增多时，发动机尺寸和曲轴就成为一个问题。
解决这个问题的办法就是采用V 形（汽缸呈两列布置，且两列气缸之间夹角为V 形）发动机。
这个设计使发动机尺寸和曲轴都变得更短且更坚硬。
前置发动机纵向安装，既可前轮驱动也可后轮驱动。
后置发动机是将发动机安装在后轮后面。
发动机可横置或纵置，一般情况下为后轮驱动。
1.4 电气系统电气系统为起动机、点火系统、照明灯具、取暖器提供电能。
该电平由一个充电电路维护。
1.4.1 充电充电系统为所有汽车电子元件提供电能。
充电系统主要包括：蓄电池，交流发电机，电压调节器，即通常是交流发电机上不可或缺的，充电警告或指示灯和金属丝连成一个完整电路。
蓄电池为起动提供电能 ,然后发动机工作，交流发电机就为所有的电子元件提供电能。
同时也给蓄电池充电即用来使发动机起动。
电压调节器有过充保护作用。
1.4.2 起动起动系统包括：蓄电池、电缆、起动机、飞轮和换向器。
起动时，有两个动作同时运行，该起动机齿轮与飞轮齿圈啮合，并起动电机，然后运行传输到发动机曲轴。
起动机电机将起动机安装在发动机缸体上并由电池供电。
外文翻译---制动系统
外文翻译---制动系统附录1Hydraulic Brake SystemsThe braking system is the most important system in cars. If the brake system fail, the result can be disastrous.When you step on the brake pedal, you expect the vehicle to stop. The brake pedal operates a hydraulic system that is used for two reasons. First, fluid under pressure can be carried to all parts of the vehicle by small hoses or metal lines with out taking up a lot of room or causing routing problems. Second, the hydraulic fluid offers a great mechanical advantage-little foot pressure is required on the pedal, but a great deal of pressure is generated at the wheels. The brake pedal is linked to a piston in the brake master cylinder, which is filled with hydraulic brake fluid. The master cylinder consists of a cylinder containing a small piston and a fluid reservoir.Modern master cylinders are actually two separate cylinders. Such a system is called a dual circuit, because the front cylinder is connected to the front brakes and the rear cylinder to the rear brakes. (Some vehicles are connected diagonally.) The two cylinders are actually separated, allowing for emergency stopping power should one part of the system fail.The entire hydraulic system from the master cylinder to the wheels is full of hydraulic brake fluid. When the brake pedal is depressed, the pistons in the master cylinder are forced to move, exerting tremendous force on the fluid in the lines. The fluid has nowhere to go, and forces the wheel cylinder pistons (drum brakes) or caliper pistons (disc brakes) to exert pressure on the brake shoes or pads. The friction between the brake shoe and wheel drum or the brake pad and rotor (disc) slows the vehicle and eventually stops it.Also attached to the brake pedal is a switch that lights the brake lights as the pedal is depressed. The lights stay on until the brake pedal is released and returns to its normal position.Each wheel cylinder in a drum brake system contains two pistons, one at either end, which push outward in opposite directions. In disc brake systems, the wheel cylinders are part of the caliper (there can be as many as four or as few asone). Whether disc or drum type, all pistons use some type of rubber seal to prevent leakage around the piston, and a rubber dust boot seals the outer ends of the wheel cylinders against dirt and moisture.When the brake pedal is released, a spring pushes the master cylinder pistons back to their normal positions. Check valves in the master cylinder piston allow fluid to flow toward the wheel cylinders or calipers as the piston returns. Then as the brake shoe return springs pull the brake shoes back to the released position, excess fluid returns to the master cylinder through compensating ports, which have been uncovered as the pistons move back. Any fluid that has leaked from the system will also be replaced through the compensating ports.All dual circuit brake systems use a switch to activate a light, warning of brake failure. The switch is located in a valve mounted near the master cylinder.A piston in the valve receives pressure on each end from the front and rear brake circuits. When the pressures are balanced, the piston remains stationary, but when one circuit has a leak, greater pressure during the application of the brakes will force the piston to one side or the other, closing the switch and activating the warning light. The light can also be activated by the ignition switch during engine starting or by the parking brake.Front disc, rear drum brake systems also have a metering valve to prevent the front disc brakes from engaging before the rear brakes have contacted the drums. This ensures that the front brakes will not normally be used alone to stop the vehicle. A proportioning valve is also used to limit pressure to the rear brakes to prevent rear wheel lock-up during hard braking.1. Friction materialsBrake shoes and pads are constructed in a similar manner. The pad or shoe is composed of a metal backing plate and a friction lining. The lining is either bonded (glued) to the metal, or riveted. Generally, riveted linings provide superior performance, but good quality bonded linings are perfectly adequate.Friction materials will vary between manufacturers and type of pad and the material compound may be referred to as: asbestos, organic, semi-metallic, metallic. The difference between these compounds lies in the types and percentages of friction materials used, material binders and performance modifiers.Generally speaking, organic and non-metallic asbestos compound brakesare quiet, easy on rotors and provide good feel. But this comes at the expense of high temperature operation, so they may not be your best choice for heavy duty use or mountain driving. In most cases, these linings will wear somewhat faster than metallic compound pads, so you will usually replace them more often. But, when using these pads, rotors tend to last longer.Semi-metallic or metallic compound brake linings will vary in performance based on the metallic contents of the compound. Again, generally speaking, the higher the metallic content, the better the friction material will resist heat. This makes them more appropriate for heavy duty applications, but at the expense of braking performance before the pad reaches operating temperature. The first few applications on a cold morning may not give strong braking. Also, metallic and semi-metallic are more likely to squeal. In most cases, metallic compounds last longer than non-metallic pads, but they tend to cause more wear on the rotors. If you use metallic pads, expect to replace the rotors more often.When deciding what type of brake lining is right for you, keep in mind that today's modern cars have brake materials which are matched to the expected vehicle＇s performance capabilities. Changing the material from OEM specification could adversely affect brake feel or responsiveness. Before changing the brake materials, talk to your dealer or parts supplier to help decide what is most appropriate for your application. Remember that heavy use applications such as towing, stop and go driving, driving down mountain roads, and racing may require a change to a higher performance material.Some more exotic materials are also used in brake linings, among which are Kevlar and carbon compounds. These materials have the capability of extremely good performance for towing, mountain driving or racing. Wear characteristics can be similar to either the metallic or the non-metallic linings, depending on the product you buy. Most race applications tend to wear like metallic linings, while many of the street applications are more like the non-metallic.2. Brake fluidOn a disk brake, the fluid from the master cylinder is forced into a caliper where it presses against a piston. The piston, in-turn, squeezes two brake pads against the disk(rotor)which is attached to the wheel, forcing it to slow down or stop. This process is similar to a bicycle brake where two rubber pads rub against the wheel rim creating friction.With drum brakes, fluid is forced into the wheel cylinder which pushes the brake shoes out so that the friction linings are pressed against the drum which is attached to the wheel, causing the wheel to stop.In either case, the friction surfaces of the pads on a disk brake system, or the shoes on a drum brake convert the forward motion of the vehicle into heat. Heat is what causes the friction surfaces (linings) of the pads and shoes to eventually wear out and require replacement.Brake fluid is a special oil that has specific properties. It is designed to withstand cold temperatures without thickening as well as very high temperatures without boiling.(If the brake fluid should boil, it will cause you to have a spongy pedal and the car will be hard to stop). Figure shows a brake hydraulic system.The brake fluid reservoir is on top of the master cylinder. Most cars today have a transparent r reservoir so that you can see the level without opening the cover. The brake fluid level will drop slightly as the brake pads wear. This is a normal condition and no cause for concern. If the level drops noticeably over a short period of time or goes down to about two thirds full, have your brakes checked as soon as possible. Keep the reservoir covered except for the amount of time you need to fill it and never leave a cam of brake fluid uncovered. Brake fluid must maintain a very high boiling point. Exposure to air will cause the fluid to absorb moisture which will lower that boiling point.The brake fluid travels from the master cylinder to the wheels through a series of steel tubes and reinforced rubber hoses. Rubber hoses are only used in places that require flexibility, such as at the front wheels, which move up and down as well as steer. The rest of the system uses non-corrosive seamless steel tubing with special fittings at all attachment points. If a steel line requires a repair, the best procedure is to replace the compete line. If this is not practical, a line can be repaired using special splice fittings that are made for brake system repair. You must never use copper tubing to repair a brake system. They are dangerous and illegal.制动系统制动系统是汽车中最重要的系统。
汽车专业英语翻译
汽车专业英语翻译Unit 1 Automotive BasicsAutomobiles, trucks, and buses are essential forms of transportation. They are complex machines made up of many parts. These parts can be grouped into a number of systems. An understanding of how the system work will help you understand how the automobile works.轿车、卡车和客车是交通运输的重要组成部分。
它们都是由许多部件组成的复杂机器。
这些部件可以归类为汽车的几个组成系统。
了解这些各个小系统是如何工作的将有助于我们理解整个汽车系统是如何工作。
An automobile can be divided into two basic parts: a body and a chassis. The body is the enclosure that houses the engine, passengers, and cargo. It is the part of the automobile that you see. The chassis is that part of the automobile beneath the body.汽车可以分为两个基本部分：车身和底盘。
车身包围发动机、乘客和行，它是汽车你所看到的部分。
而车身以下的部分就是底盘。
An automobile body is a sheet metal shell with windows, doors, a hood, and a trunk deck built into it. It provides a protective covering for the engine, passengers, and cargo. The body is designed to keep passengers safe and comfortable. For example, insulation in the body reduces noise and protects against heat and cold. The body styling provides an attractive, colorful, modern appearance for the vehicle. It is streamlined to lessen wind resistance and to keep the car from swaying at driving speeds.轿车车身是一个钣金件壳体，它上面有车窗、车门、发送机罩和行舱门等部件，它给发动机、乘客和行提供防护。
f1汽车制动系统外文翻译
Automobile Brake SystemThe braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes, the driver commands a stopping force ten times as powerful 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.Two complete independent braking systems are used on the car. They are the service brake and the parking brake.The service brake acts to slow, stop, or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. The primary purpose of the brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by when a separate parking brake foot pedal or hand lever is set.The brake system is composed of the following basic components: the “master cylinder” which is located under the hood, and is directly connected to the brake pedal, converts driver foot’s 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 conditions, fills the system. “Shoes” and “pads” are pushed by the slave cylinders to contact the “drums” and “rotors” thus causing drag, which (hopefully) slows the car.The typical brake system consists of disk brakes in front and either disk or drum brakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder .Basically, all car brakes are friction brakes. When the driver applies the brake, the control device forces brake shoes, or pads, against the rotating brake drum or disks atwheel. Friction between the shoes or pads and the drums or disks then slows or stops the wheel so that the car is braked.In most modern brake systems, there is a fluid-filled cylinder, called master cylinder, which contains two separate sections, there is a piston in each section and both pistons are connected to a brake pedal in the driver’s compartment. When the brake is pushed down, brake fluid is sent from the master cylinder to the wheels.At the wheels, the fluid pushes shoes, or pads, against revolving drums or disks. The friction between the stationary shoes, or pads, and the revolving drums or disks slows and stops them. This slows or stops the revolving wheels, which, in turn, slow or stop the car.The brake fluid reservoir is on top of the master cylinder. Most cars today have a transparent r reservoir so that you can see the level without opening the cover. The brake fluid level will drop slightly as the brake pads wear. This is a normal condition and no cause for concern. If the level drops noticeably over ashort period of time or goes down to about two thirds full, have your brakes checked as soon as possible. Keep the reservoir covered except for the amount of time you need to fill it and never leave a cam of brake fluid uncovered. Brake fluid must maintain a very high boiling point. Exposure to air will cause the fluid to absorb moisture which will lower that boiling point.The brake fluid travels from the master cylinder to the wheels through a series of steel tubes and reinforced rubber hoses. Rubber hoses are only used in places that require flexibility, such as at the front wheels, which move up and down as well as steer. The rest of the system uses non-corrosive seamless steel tubing with special fittings at all attachment points. If a steel line requires a repair, the best procedure is to replace the compete line. If this is not practical, a line can be repaired using special splice fittings that are made for brake system repair. You must never use copper tubing to repair a brake system. They are dangerous and illegal.Drum brakes, it consists of the brake drum, an expander, pull back springs, a stationary back plate, two shoes with friction linings, and anchor pins. The stationary back plate is secured to the flange of the axle housing or to the steering knuckle. The brake drum is mounted on the wheel hub. There is a clearance between the inner surface of the drum and the shoe lining. To apply brakes, the driver pushes pedal, the expander expands the shoes and presses them to the drum. Friction between the brake drum and the friction linings brakes the wheels and the vehicle stops. To release brakes, the driver release the pedal, the pull back spring retracts the shoes thus permitting free rotation of the wheels.Disk brakes, it has a metal disk instead of a drum. A flat shoe, or disk-brake pad, is located on each side of the disk. The shoes squeeze the rotatin g disk to stop the car. Fluid from the master cylinder forces the pistons to move in, toward the disk. This action pushes the friction pads tightly against the disk. The friction between the shoes and disk slows and stops it. This provides the braking action. Pistons are made of either plastic or metal. There are three general types of disk brakes. They are the floating-caliper type, the fixed-caliper type, and the sliding-caliper type.Floating-caliper and sliding-caliper disk brakes use a single piston. Fixed-caliper disk brakes have either two or four pistons.Brakes - what do they do?Brakes are designed to slow down your vehicle but probably not by the means that you think. The common misconception is that brakes squeeze against a drum or disc, and the pressure of the squeezing action is what slows you down. This in fact is only part of the equation. Brakes are essentially a mechanism to change energy types. When you're travelling at speed, your vehicle has kinetic energy. When you apply the brakes, the pads or shoes that press against the brake drum or rotor convert that energy into thermal energy via friction. The cooling of the brakes dissipates the heat and the vehicle slows down. It's the First Law of Thermodynamics, sometimes known as the law of conservation of energy. This states that energy cannot be created nordestroyed, it can only be converted from one form to another. In the case of brakes, it is converted from kinetic energy to thermal energy.Angular force. Because of the configuration of the brake pads and rotor in a disc brake, the location of the point of contact where the friction is generated also provides a mechanical moment to resist the turning motion of the rotor.Thermodynamics, brake fade and drilled rotors.If you ride a motorbike or drive a race car, you're probably familiar with the term brake fade, used to describe what happens to brakes when they get too hot. A good example is coming down a mountain pass using your brakes rather than your engine to slow you down. As you start to come down the pass, the brakes on your vehicle heat up, slowing you down. But if you keep using them, the rotors or drums stay hot and get no chance to cool off. At some point they can't absorb any more heat so the brake pads heat up instead. In every brake pad there is the friction material that is held together with some sort of resin and once this starts to get too hot, the resin starts to vapourise, forming a gas. Because the gas can't stay between the pad and the rotor, it forms a thin layer between the two whilst trying to escape. The pads lose contact with the rotor, reducing the amount of friction and voila. Complete brake fade.。
中英文文献翻译-制动系统
英文原文Brake systemsWe all know that pushing down on the brake pedal slows a car to a stop. But how does this happen? How does your car transmit the force from your leg to its wheels? How does it multiply the force so that it is enough to stop something as big as a car?When you depress your brake pedal, your car transmits the force from your foot to its brakes through a fluid. Since the actual brakes require a much greater force than you could apply with your leg, your car must also multiply the force of your foot. It does this in two ways:∙Mechanical advantage (leverage)∙Hydraulic force multiplicationThe brakes transmit the force to the tires using friction, and the tires transmit that force to the road using friction also. Before we begin our discussion on the components of the brake system, we'll cover these three principles:∙Leverage∙Hydraulics∙FrictionLeverage and HydraulicsIn the figure below, a force F is being applied to the left end of the lever. The left end of the lever is twice as long (2X) as the right end (X). Therefore, on the right end of the lever a force of 2F is available, but it acts through half of the distance (Y) that the left end moves (2Y). Changing the relative lengths of the left and right ends of the lever changes the multipliers.The basic idea behind any hydraulic system is very simple: Force applied at one point is transmitted to another point using an incompressible fluid, almost always an oil of some sort. Most brake systems also multiply the force in the process. Here you can see the simplest possible hydraulic system:Your browser does not support JavaScript or it is disabled.Simple hydraulic systemIn the figure above, two pistons (shown in red) are fit into two glass cylinders filled with oil (shown in light blue) and connected to one another with an oil-filled pipe. If you apply adownward force to one piston (the left one, in this drawing), then the force is transmitted to the second piston through the oil in the pipe. Since oil is incompressible, the efficiency is very good -- almost all of the applied force appears at the second piston. The great thing about hydraulic systems is that the pipe connecting the two cylinders can be any length and shape, allowing it to snake through all sorts of things separating the two pistons. The pipe can also fork, so that one master cylinder can drive more than one slave cylinder if desired, as shown in here:Your browser does not support JavaScript or it is disabled.Master cylinder with two slavesThe other neat thing about a hydraulic system is that it makes force multiplication (or division) fairly easy. If you have read How a Block and Tackle Works or How Gear Ratios Work, then you know that trading force for distance is very common in mechanical systems. In a hydraulic system, all you have to do is change the size of one piston and cylinder relative to the other, as shown here:Your browser does not support JavaScript or it is disabled.Hydraulic multiplicationTo determine the multiplication factor in the figure above, start by looking at the size of the pistons. Assume that the piston on the left is 2 inches (5.08 cm) in diameter (1-inch / 2.54 cm radius), while the piston on the right is 6 inches (15.24 cm) in diameter (3-inch / 7.62 cm radius).The area of the two pistons is Pi * r2. The area of the left piston is therefore 3.14, while the area of the piston on the right is 28.26. The piston on the right is nine times larger than the piston on the left. This means that any force applied to the left-hand piston will come out nine times greater on the right-hand piston. So, if you apply a 100-pound downward force to the left piston, a 900-pound upward force will appear on the right. The only catch is that you will have to depress the left piston 9 inches (22.86 cm) to raise the right piston 1 inch (2.54 cm).A Simple Brake SystemBefore we get into all the parts of an actual car brake system, let's look at a simplified system:Your browser does not support JavaScript or it is disabled.A simple brake systemYou can see that the distance from the pedal to the pivot is four times the distance from the cylinder to the pivot, so the force at the pedal will be increased by a factor of four before it is transmitted to the cylinder.You can also see that the diameter of the brake cylinder is three times the diameter of the pedal cylinder. This further multiplies the force by nine. All together, this system increases the force of your foot by a factor of 36. If you put 10 pounds of force on the pedal, 360 pounds (162 kg) will be generated at the wheel squeezing the brake pads.There are a couple of problems with this simple system. What if we have a leak? If it is a slow leak, eventually there will not be enough fluid left to fill the brake cylinder, and the brakes will not function. If it is a major leak, then the first time you apply the brakes all of the fluid will squirt out the leak and you will have complete brake failure.Drum brakes work on the same principle as disc brakes: Shoes press against a spinning surface. In this system, that surface is called a drum.Figure 1. Location of drum brakes. See more drum brake pictures.Many cars have drum brakes on the rear wheels and disc brakes on the front. Drum brakes have more parts than disc brakes and are harder to service, but they are less expensive to manufacture, and they easily incorporate an emergency brake mechanism.In this edition of HowStuffWorks, we will learn exactly how a drum brake system works, examine the emergency brake setup and find out what kind of servicing drum brakes need.Figure 2. Drum brake with drum in placeFigure 3. Drum brake without drum in placeLet's start with the basics.The Drum BrakeThe drum brake may look complicated, and it can be pretty intimidating when you open one up. Let's break it down and explain what each piece does.Figure 4. Parts of a drum brakeLike the disc brake, the drum brake has two brake shoes and a piston. But the drum brake also has an adjuster mechanism, an emergency brake mechanism and lots of springs.First, the basics: Figure 5 shows only the parts that provide stopping power.Your browser does not support JavaScript or it is disabled.Figure 5. Drum brake in operationWhen you hit the brake pedal, the piston pushes the brake shoes against the drum. That's pretty straightforward, but why do we need all of those springs?This is where it gets a little more complicated. Many drum brakes are self-actuating. Figure 5 shows that as the brake shoes contact the drum, there is a kind of wedging action, which has the effect of pressing the shoes into the drum with more force.The extra braking force provided by the wedging action allows drum brakes to use a smaller piston than disc brakes. But, because of the wedging action, the shoes must be pulled away from the drum when the brakes are released. This is the reason for some of the springs. Other springs help hold the brake shoes in place and return the adjuster arm after it actuates.Brake AdjusterFor the drum brakes to function correctly, the brake shoes must remain close to the drum without touching it. If they get too far away from the drum (as the shoes wear down, for instance), the piston will require more fluid to travel that distance, and your brake pedal will sink closer to the floor when you apply the brakes. This is why most drum brakes have an automatic adjuster.Figure 6. Adjuster mechanismNow let's add in the parts of the adjuster mechanism. The adjuster uses the self-actuation principle we discussed above.Your browser does not support JavaScript or it is disabled.Figure 7. Drum brake adjuster in operationIn Figure 7, you can see that as the pad wears down, more space will form between the shoe and the drum. Each time the car stops while in reverse, the shoe is pulled tight against the drum. When the gap gets big enough, the adjusting lever rocks enough to advance the adjuster gear by one tooth. The adjuster has threads on it, like a bolt, so that it unscrews a little bit when it turns, lengthening to fill in the gap. When the brake shoes wear a little more, the adjuster can advance again, so it always keeps the shoes close to the drum.Some cars have an adjuster that is actuated when the emergency brake is applied. This type of adjuster can come out of adjustment if the emergency brake is not used for long periods of time. So if you have this type of adjuster, you should apply your emergency brake at least once a week.ServicingThe most common service required for drum brakes is changing the brake shoes. Some drum brakes provide an inspection hole on the back side, where you can see how much material is left on the shoe. Brake shoes should be replaced when the friction material has worn down to within 1/32 inch (0.8 mm) of the rivets. If the friction material is bonded to the backing plate (no rivets), then the shoes should be replaced when they have only 1/16 inch (1.6 mm) of material left.Photo courtesy of a local AutoZone storeFigure 9. Brake shoeJust as in disc brakes, deep scores sometimes get worn into brake drums. If a worn-out brake shoe is used for too long, the rivets that hold the friction material to the backing can wear grooves into the drum. A badly scored drum can sometimes be repaired by refinishing. Where disc brakes have a minimum allowable thickness, drum brakes have a maximum allowable diameter. Since the contact surface is the inside of the drum, as you remove material from the drum brake the diameter gets bigger.The current Bosch component Anti-lock Braking System (ABSⅡ), is a second generation design wildly used by European automakers such as BWM, Mercedes-Benz and Porsche. ABSⅡsystem consists of : four wheel speed sensor, electronic control unit and modulator assembly.A speed sensor is fitted at each wheel sends signals about wheel rotation to control unit. Each speed sensor consists of a sensor unit and a gear wheel. The front sensor mounts to the steering knuckle and its gear wheel is pressed onto the stub axle that rotates with the wheel. The rear sensor mounts the rear suspension member and its gear wheel is pressed onto the axle. The sensor itself is a winding with a magnetic core. The core creates a magnetic field around the winding, and as the teeth of the gear wheel move through this field, an alternating current is induced in the winding. The control unit monitors the rate o change in this frequency to determine impending brake lockup.The control unit’s function can be divided into three parts: signal processing, logic and safety circuitry. The signal processing section is the converter that receives the alternating current signals form the speed sensors and converts them into digital form for the logic section. The logic section then analyzes the digitized signals to calculate any brake pressure changes needed. If impending lockup is sensed, the logic section sends commands to the modulator assembly.The hydraulic modulator assembly regulates pressure to the wheel brakes when it receives commands from the control utuit. The modulator assembly can maintain or reduce pressure over the level it receives from the master cylinder, it also can never apply the brakes by itself. The modulator assembly consists of three high-speed electric solenoid valves, two fluid reservoirs and a turn delivery pump equipped with inlet and outlet check valves. The modulator electrical connector and controlling relays are concealed under a plastic cover of the assembly.Each front wheel is served by electric solenoid valve modulated independently by the control unit. The rear brakes are served by a single solenoid valve and modulated together using the select-low principle. During anti-braking system operation, the control unit cycles the solenoidvalves to either hold or release pressure the brake lines. When pressure is released from the brake lines during anti-braking operation, it is routed to a fluid reservoir. There is one reservoir for the front brake circuit. The reservoirs are low-pressure accumulators that store fluid under slight spring pressure until the return delivery pump can return the fluid through the brake lines to the master cylinder.中文译文制动系统众所周知，踩下制动踏板可以使汽车减速至停止。
汽车专业英语9 Chapter 5 Braking System
Chapter 5 Braking Systems
5.1 Overview of Braking Systems
There are three kinds of braking systems: service brake system, parking brake system and additional retarder braking system. The service brake system is the main braking system used to slow down or even stop the car that’s running at a high speed and guarantee the safety of passengers. It is foot-operated by the driver depressing and releasing the brake pedal. A parking brake system can prevent the auto slipping away from its parking place, even if it is parked on a steep slope. It is also called the hand brake.
行车制动系统 驻车制动系统 缓速制动系统
brake pedal vacuum booster master cylinder brake line
制动踏板 真空助力器 主缸 制动管路
Chapter 5 Braking Systems
5.1 Overview of Braking Systems
Байду номын сангаас
drum brake disc brake brake shoe brake drum wheel cylinder friction lining brake caliper Brake fluid check valve
汽车专业外文翻译(英文+译文)
原文：Routine brake system maintenanceThe braking system is the most important system on a car. If the brakes don't work properly, the result can be disastrous. So the good brakes are essential for safety.There are two completely independent braking systems on a car. One is the service brake, and the other is parking brake. The service brake acts to slow, stop, or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. The parking brake's purposes are to hold a car stationary while it is unattended, and to keep the car from rolling on unleveled ground. It is also called the handbrake.Basically, all car brakes are friction brakes. When the driver applies the brake, the control device will force brake shoes or pads against the rotating brake drums or discs at wheels. Friction between the shoes or pads and the drums or disks then slows or stops the wheels so that the car is braked.Disc brakeDisc brakes are used on the front wheels of most cars and on all four wheels on many cars.The main components of a disc brake are the brake pads, the caliper which contains a piston, and the rotor which is mounted to the hub.The disc brake is a lot like the brakes on a bicycle. Bicycle brakes have a caliper, which squeezes the brake pads against the wheel. In a disc brake, the brake pads squeeze the rotor instead of the wheel, and the force is transmitted hydraulically instead of through a cable. Friction between the pads and the disc slows the disc down.A moving car has a certain amount of kinetic energy, and the brakes have to remove this energy from the car in order to stop it. The brakes convert the kinetic energy to heat generated by the friction between the pads and the disc, so the car stops.Drum brakeSo if disk brakes are so great, how come we still have cars with drum brakes? The reason is cost. While all most vehicles for many years have disk brakes on the front wheels, drum brakes are cheaper to produce for the rear wheels. Drum brake is shown in Fig.Drum brakes consist of a backing plate, brake shoes, brake drum, wheel cylinder, return springs and an automatic or self-adjusting system. When you apply the brakes, the wheel cylinder pushes the brake shoes into contact with the machined surface on the inside of the drum. When the pressure is released, return springs pull the shoes back to their rest position. As the brake linings wear, the shoes must travel a greater distance to reach the drum. When the distance reaches a certain point, a self-adjusting mechanism automatically reacts byadjusting the rest position of the shoes so that they are closer to the drum.Hydraulic Brake SystemsWhen the operator steps on the brake pedal, the brake pedal operates a hydraulic system.The typical brake system is composed of the following basic components(1) Master cylinder. That is directly connected to the brake pedal, converts your foot's mechanical pressure into hydraulic pressure.(2) Brake lines and brake hoses, they connect the master cylinder to the wheel cylinders located at each wheel.(3) Brake fluid: that is special oil that has special properties. It is designed to withstand cold temperature without thickening as well as very high temperature without boiling.In the brake system, master cylinder contains two separate sections, there is a piston in each section and both pistons are connected to a brake pedal in the driver's compartment. When the brake is pushed down, brake fluid is sent from the master cylinder to the wheels. At the wheels, the fluid pushes shoes, or pads, against revolving drums or disks, which can slow and stop car. This slows or stops the revolving wheels, which, in turn, slow or stop the car.Routine maintenance of automobile brake fluid: Usually brake fluid maintenance period of 2 years or 48,000 km. Recommended brake fluid on the maintenance period, the European car manufacturers generally set a few years; and Japan and the United States car manufacturers are generally in their owner's manual have detailed descriptions. The abs function with anti-lock braking system, brake fluid and timely supplement is especially important. This is mainly due to energy storage in the pollution of dust and moisture of the body will lead to expensive failure, and thus laid security risk when vehicle braking force owners to find weak, you can use brake fluid test strips humidity assisted analysis of whether there is any fault of defect caused by brake fluid. If the brake fluid for the failure of the root causes of lack of sufficient quantity to be added in time brake fluid. By the brake fluid tank vent in a normal infiltration (or when tank lid open non-regular access to) the moisture and dust reduced brake fluid maintenance cycle. Maintenance of the brake fluid in the same time, must not neglect the wheel brake parts.Auto brake pad, brake drum, rotating body, and brake calipers: the current drive vehicle for leading the trend, people are concerned about how to play the 2 / 3 of the front brake lines brake tasks for scientific and effective maintenance. Now, after a variety of drive, all-wheel drive, trucks and suv blossom everywhere, people "before re-light after the" traditional concept has gradually changed.Gradually replace the asbestos linings in the semi-metallic brake pad will cause the whole surface of rotating serious wear and tear. Brake parts on the car wheel or brake pad inspection is a complex task, not simply from a visual look at both sides of the front brakepads wear the middle point. In actual operation, even if the brake caliper of open distance just to let you see both sides of the brake pad, it does not mean we can be handy, unimpeded operation of the. In addition, the popularization of brake shield, and the brake pad of rotating the contact surface is multi-block, hard look. As for the rear wheel with disc brake, it is hidden, is difficult to comprehend the appearance.Typically, the only system in the apparent leak, we will focus on checking brake fluid sealing. The comprehensive system of inspection, including the traditional static checking (that is, to find leaks in situ static) and dynamic checks (ie check the seal during braking). In any case, when the vehicle braking system to maintain up to 48 000 km driving range, they need the vehicle's braking system to conduct a comprehensive professional maintenance Brake rotating body of minor scratches do not cause illness. But since the fastening nut tightening force thickness of inequality and uneven brake rotating body rotation caused by excessive wear and tear will seriously affect the braking performance. To reduce weight, many rotating body size using unconventional structure, which is difficult to meet some of the machine tool clamping the basic requirements. If you find a rotating body has been processed, then follow the same axle of the second rotating body is only the size of its replacement. In theory, you can only replace a rotating body, but to get the best balance between braking effect, or the proposed replacement with two on the same axle rotating body. The proposal also applies to vehicles during braking, brake caliper piston through the experience back movement, we can complete the key features of the automatic brake calipers inspection. If the brake caliper piston back position is unsound, please replace a new brake caliper; If you want to discharge or filling brake fluid, make sure relief valve can be normally open; if the relief valve setting, replace the new The brake caliper.If the asbestos linings have worn 3.175mm, this time even under light loading, the security of driving range has also been very limited. Also, if needed at this time of high load brake, the wear lining weak braking force will make the traffic safety compromised.Some rear disc brake, rear-drive rotary body with a cap, the cap body also acts as a rotary brake drum. There are many car owners often overlook the parking brake will cancel the direct-drive vehicles, the rotating body and the brake shoes in direct metal - metal friction, the result is bound to cause a rotating body, brake pads and brake shoes of serious wear and tear.译文：汽车制动系统的日常维修保养制动系统是汽车上最重要的系统。
汽车专业英语2版参考译文-20180227-5
第5 章制动系统** 制动系统概述制动系统对于汽车非常重要。
如果制动器不能正常工作，后果可能是灾难性的。
制动器实际上是个能量转换装置，它将汽车的动能转换成热能。
汽车上有三类制动系统：行车制动系统、驻车制动系统、应急制动系统和附加的缓速制动系统。
行车制动系统是主要制动系统，可以使高速行驶的汽车减速甚至停车，从而保证乘客的安全。
它是通过驾驶员踩下或松开制动踏板以脚制动的。
驻车制动系统则可以防止停放的汽车脱离停车位置，即便它停在一个陡坡上。
这种制动系统也叫手制动。
制动系统一般由制动器及其操纵机构组成。
液压制动系统的主要组成部件包括制动踏板、真空助力器、制动主缸、制动管路和制动器，如图5-1所示。
为了增加安全性，大多数现代汽车的制动系统都分成两个回路，每个回路系统作用在两个车轮上。
图5-1 液压制动系统汽车主要有两种类型的制动器：鼓式制动器和盘式制动器。
基本上所有的制动器都是摩擦制动器。
驾驶员刹车时，操纵装置对制动蹄或制动块施加压力，与车轮的制动鼓或制动盘旋转反向。
制动蹄与制动鼓或制动块与制动盘之间的摩擦就会使车轮减速或停止，这样就实现了刹车。
** 制动器** 鼓式制动器鼓式制动器一般由制动底板、制动轮缸、制动蹄、制动鼓和制动间隙调整机构组成，如图5-2所示。
鼓式制动器是利用带有摩擦片的内部延展制动蹄在一个叫做制动鼓的旋转制动表面内工作的。
通过一个叫做液压制动分泵的液压缸将制动蹄径向撑开，这样摩擦片就会压住制动鼓，实现刹车（见图5-3）。
图5-2 鼓式制动器图5-3 鼓式制动器原理** 盘式制动器盘式制动器的主要部件包括制动缸、制动盘和制动钳等。
盘式制动器很像自行车刹车。
自行车刹车有一个夹钳，它可以挤压制动块从而使车轮停止。
在盘式制动器中，制动块挤压转子而非车轮，且挤压力是通过液压传动的，而不是通过线管传递。
制动块和制动盘之间的摩擦力使得制动盘减速（见图5-4和5-5）。
Fig. 5-4 盘式制动器Fig. 5-5 盘式制动器原理** 制动传动装置** 制动主缸在现代制动系统中，制动主缸都是发动机助力的。
汽车工程专业外文翻译--汽车制动系统
Automobile Brake SystemThe braking system is the most important system in cars. If the brakes fail, the result can be disastrous. Brakes are actually energy conversion devices, which convert the kinetic energy (momentum) of the vehicle into thermal energy (heat).When stepping on the brakes, the driver commands a stopping force ten times as powerful 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.Two complete independent braking systems are used on the car. They are the service brake and the parking brake.The service brake acts to slow, stop, or hold the vehicle during normal driving. They are foot-operated by the driver depressing and releasing the brake pedal. Theprimary purpose of the brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by when a separate parking brake foot pedal or hand lever is set.The brake system is composed of the following basic components: the “master cylinder” which is located under the hood, and is directly connected to the brake pedal, converts driver foot’s 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 conditions, fills the system. “Shoes” and “pads” are pushed by the slave cylinders to contact the “drums” and “rotors” thus causing drag, which (hopefully) slows the car.The typical brake system consists of disk brakes in front and either disk or drumbrakes in the rear connected by a system of tubes and hoses that link the brake at each wheel to the master cylinder (Figure).Basically, all car brakes are friction brakes. When the driver applies the brake, the control device forces brake shoes, or pads, against the rotating brake drum or disks at wheel. Friction between the shoes or pads and the drums or disks then slows or stops the wheel so that the car is braked.In most modern brake systems (see Figure 15.1), there is a fluid-filled cylinder, called master cylinder, which contains two separate sections, there is a piston in each section and both pistons are connected to a brake pedal in the driver’s compartment. When the brake is pushed down, brake fluid is sent from the master cylinder to the wheels. At the wheels, the fluid pushes shoes, or pads, against revolving drums or disks. The friction between the stationary shoes, or pads, and the revolving drums or disks slows and stops them. This slows or stops the revolving wheels, which, in turn, slow or stop the car.The brake fluid reservoir is on top of the master cylinder. Most cars today have a transparent r reservoir so that you can see the level without opening the cover. The brake fluid level will drop slightly as the brake pads wear. This is a normal condition and no cause for concern. If the level drops noticeably over a short period of time or goes down to about two thirds full, have your brakes checked as soon as possible. Keep the reservoir covered except for the amount of time you need to fill it and never leave a cam of brake fluid uncovered. Brake fluid must maintain a very high boiling point. Exposure to air will cause the fluid to absorb moisture which will lower that boiling point.The brake fluid travels from the master cylinder to the wheels through a series of steel tubes and reinforced rubber hoses. Rubber hoses are only used in places that require flexibility, such as at the front wheels, which move up and down as well as steer. The rest of the system uses non-corrosive seamless steel tubing with special fittings at all attachment points. If a steel line requires a repair, the best procedure is to replace the compete line. If this is not practical, a line can be repaired using special splice fittings that are made for brake system repair. You must never use copper tubing to repair a brake system. They are dangerous and illegal.Drum brakes, it consists of the brake drum, an expander, pull back springs, a stationary back plate, two shoes with friction linings, and anchor pins. The stationaryback plate is secured to the flange of the axle housing or to the steering knuckle. The brake drum is mounted on the wheel hub. There is a clearance between the inner surface of the drum and the shoe lining. To apply brakes, the driver pushes pedal, the expander expands the shoes and presses them to the drum. Friction between the brake drum and the friction linings brakes the wheels and the vehicle stops. To release brakes, the driver release the pedal, the pull back spring retracts the shoes thus permitting free rotation of the wheels.Disk brakes, it has a metal disk instead of a drum. A flat shoe, or disk-brake pad, is located on each side of the disk. The shoes squeeze the rotating disk to stop the car. Fluid from the master cylinder forces the pistons to move in, toward the disk. This action pushes the friction pads tightly against the disk. The friction between the shoes and disk slows and stops it. This provides the braking action. Pistons are made of either plastic or metal. There are three general types of disk brakes. They are the floating-caliper type, the fixed-caliper type, and the sliding-caliper type. Floating-caliper and sliding-caliper disk brakes use a single piston. Fixed-caliper disk brakes have either two or four pistons.The brake system assemblies are actuated by mechanical, hydraulic or pneumatic devices. The mechanical leverage is used in the parking brakes fitted in all automobile. When the brake pedal is depressed, the rod pushes the piston of brake master cylinder which presses the fluid. The fluid flows through the pipelines to the power brake unit and then to the wheel cylinder. The fluid pressure expands the cylinder pistons thus pressing the shoes to the drum or disk. If the pedal is released, the piston returns to the initial position, the pull back springs retract the shoes, the fluid is forced back to the master cylinder and braking ceases.The primary purpose of the parking brake is to hold the vehicle stationary while it is unattended. The parking brake is mechanically operated by the driver when a separate parking braking hand lever is set. The hand brake is normally used when the car has already stopped. A lever is pulled and the rear brakes are approached and locked in the “on” position. The car may now be left without fear of its rolling away. When the driver wants to move the car again, he must press a button before the lever can be released. The hand brake must also be able to stop the car in the event of the foot brake failing. For this reason, it is separate from the foot brake uses cable or rods instead of the hydraulic system.Anti-lock Brake SystemAnti-lock brake systems make braking safer and more convenient, Anti-lock brake systems modulate brake system hydraulic pressure to prevent the brakes from locking and the tires from skidding on slippery pavement or during a panic stop.Anti-lock brake systems have been used on aircraft for years, and some domestic car were offered with an early form of anti-lock braking in late 1990’s. Recently, several automakers have introduced more sophisticated anti-lock system. Investigations in Europe, where anti-lock braking systems have been available for a decade, have led one manufacture to state that the number of traffic accidents could be reduced by seven and a half percent if all cars had anti-lock brakes. So some sources predict that all cars will offer anti-lock brakes to improve the safety of the car.Anti-lock systems modulate brake application force several times per second to hold the tires at a controlled amount of slip; all systems accomplish this in basically the same way. One or more speed sensors generate alternating current signal whose frequency increases with the wheel rotational speed. An electronic control unit continuously monitors these signals and if the frequency of a signal drops too rapidly indicating that a wheel is about to lock, the control unit instructs a modulating device to reduce hydraulic pressure to the brake at the affected wheel. When sensor signals indicate the wheel is again rotating normally, the control unit allows increased hydraulic pressure to the brake. This release-apply cycle occurs several time per second to “pump” the brakes like a driver might but at a much faster rate.In addition to their basic operation, anti-lock systems have two other things in common. First, they do not operate until the brakes are applied with enough force to lock or nearly lock a wheel. At all other times, the system stands ready to function but does not interfere with normal braking. Second, if the anti-lock system fail in any way, the brakes continue to operate without anti-lock capability. A warning light on the instrument panel alerts the driver when a problem exists in the anti-lock system.The current Bosch component Anti-lock Braking System (ABSⅡ), is a second generation design wildly used by European automakers such as BWM, Mercedes-Benz and Porsche. ABSⅡsystem consists of : four wheel speed sensor, electronic control unit and modulator assembly.A speed sensor is fitted at each wheel sends signals about wheel rotation tocontrol unit. Each speed sensor consists of a sensor unit and a gear wheel. The front sensor mounts to the steering knuckle and its gear wheel is pressed onto the stub axle that rotates with the wheel. The rear sensor mounts the rear suspension member and its gear wheel is pressed onto the axle. The sensor itself is a winding with a magnetic core. The core creates a magnetic field around the winding, and as the teeth of the gear wheel move through this field, an alternating current is induced in the winding. The control unit monitors the rate o change in this frequency to determine impending brake lockup.The control unit’s function can be divided into three parts: signal processing, logic and safety circuitry. The signal processing section is the converter that receives the alternating current signals form the speed sensors and converts them into digital form for the logic section. The logic section then analyzes the digitized signals to calculate any brake pressure changes needed. If impending lockup is sensed, the logic section sends commands to the modulator assembly.Modulator assemblyThe hydraulic modulator assembly regulates pressure to the wheel brakes when it receives commands from the control utuit. The modulator assembly can maintain or reduce pressure over the level it receives from the master cylinder, it also can never apply the brakes by itself. The modulator assembly consists of three high-speed electric solenoid valves, two fluid reservoirs and a turn delivery pump equipped with inlet and outlet check valves. The modulator electrical connector and controlling relays are concealed under a plastic cover of the assembly.Each front wheel is served by electric solenoid valve modulated independently by the control unit. The rear brakes are served by a single solenoid valve and modulated together using the select-low principle. During anti-braking system operation, the control unit cycles the solenoid valves to either hold or release pressure the brake lines. When pressure is released from the brake lines during anti-braking operation, it is routed to a fluid reservoir. There is one reservoir for the front brake circuit. The reservoirs are low-pressure accumulators that store fluid under slight spring pressure until the return delivery pump can return the fluid through the brake lines to the master cylinder.汽车制动系统制动系统是汽车中最重要的系统。
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第5 章制动系统5.1 制动系统概述制动系统对于汽车非常重要。
如果制动器不能正常工作，后果可能是灾难性的。
制动器实际上是个能量转换装置，它将汽车的动能转换成热能。
汽车上有三类制动系统：行车制动系统、驻车制动系统、应急制动系统和附加的缓速制动系统。
行车制动系统是主要制动系统，可以使高速行驶的汽车减速甚至停车，从而保证乘客的安全。
它是通过驾驶员踩下或松开制动踏板以脚制动的。
驻车制动系统则可以防止停放的汽车脱离停车位置，即便它停在一个陡坡上。
这种制动系统也叫手制动。
制动系统一般由制动器及其操纵机构组成。
液压制动系统的主要组成部件包括制动踏板、真空助力器、制动主缸、制动管路和制动器，如图5-1所示。
为了增加安全性，大多数现代汽车的制动系统都分成两个回路，每个回路系统作用在两个车轮上。
图5-1 液压制动系统汽车主要有两种类型的制动器：鼓式制动器和盘式制动器。
基本上所有的制动器都是摩擦制动器。
驾驶员刹车时，操纵装置对制动蹄或制动块施加压力，与车轮的制动鼓或制动盘旋转反向。
制动蹄与制动鼓或制动块与制动盘之间的摩擦就会使车轮减速或停止，这样就实现了刹车。
5.2 制动器5.2.1 鼓式制动器鼓式制动器一般由制动底板、制动轮缸、制动蹄、制动鼓和制动间隙调整机构组成，如图5-2所示。
鼓式制动器是利用带有摩擦片的内部延展制动蹄在一个叫做制动鼓的旋转制动表面内工作的。
通过一个叫做液压制动分泵的液压缸将制动蹄径向撑开，这样摩擦片就会压住制动鼓，实现刹车（见图5-3）。
图5-2 鼓式制动器图5-3 鼓式制动器原理5.2.2 盘式制动器盘式制动器的主要部件包括制动缸、制动盘和制动钳等。
盘式制动器很像自行车刹车。
自行车刹车有一个夹钳，它可以挤压制动块从而使车轮停止。
在盘式制动器中，制动块挤压转子而非车轮，且挤压力是通过液压传动的，而不是通过线管传递。
制动块和制动盘之间的摩擦力使得制动盘减速（见图5-4和5-5）。
Fig. 5-4 盘式制动器Fig. 5-5 盘式制动器原理5.3 制动传动装置5.3.1 制动主缸在现代制动系统中，制动主缸都是发动机助力的。
制动主缸安装在发动机舱的防火墙上，直接在驾驶员位置的前方。
典型的制动主缸实质上在一个外壳中有两个完全独立的制动腔，每腔控制两个车轮。
也就是说，如果一边失效的话，仍然可以实现刹车。
任何一边失效的话，仪表盘上的恶制动报警灯都会点亮，提醒注意有问题。
制动主缸现在已经非常可靠并且很少出现故障，但是，它们最普遍的问题就是内部泄漏。
这会导致当你的脚施以稳定的压力时，制动踏板会慢慢落向地面。
放开并立即再次踏下踏板会使得踏板恢复到常规高度。
5.3.2 制动液制动液是具有特殊性能的油液。
它冷时不稠，热时不沸腾。
如果制动液沸腾，就会导致踏板发软并且很难实现刹车。
5.3.3 助力器制动助力器（见图5-6）安装在制动总泵正后方的防火墙上，且和制动主缸一起直接与制动踏板相连。
他的目的就是扩大脚对制动踏板施加的有限压力，这样就可以使即使是让最大的汽车刹车所需要的压力也能达到最小。
助力器的动力来自发动机的真空吸力。
真空吸力是汽车发动机正常运转时的副产品，且能够在使用像制动助力器这样的功率附件时直接获取。
真空气体通过助力器上的止回阀进入助力器。
止回阀用一条橡胶软管与发动机相连，且作为一个单向阀，允许真空气体进入助力器，但是不允许排气。
5.4 防抱死制动系统防抱死制动系统（通常称为ABS）是汽车刹车时的一种防锁死系统。
它的作用是在汽车紧急制动时防止车轮抱死，充分利用轮胎与地面的最大附着力和高的侧向力系数，以提高制动减速度、缩短制动距离，从而保证汽车行驶的稳定性。
ABS系统由四部分组成：轮速传感器、液压泵、电磁阀和控制器。
图5-7 ABS5.4.1 组成轮速传感器每个车轮上都安装有轮速传感器，用于给控制单元提供轮速参考值。
轮速传感器是永磁式感应传感器，检测来自每个轮毂齿轮的脉冲信号。
当每个轮齿穿过磁场时，都产生一个电压信号。
轮速传感器是可更换式的。
传感器转子（带齿的轮）和轮毂装成一个整体，因而必须一起更换。
控制单元控制单元包括整个全部信号调节电路和输出回路。
输出回路控制液压单元，调节送往每个制动钳的管路压力。
控制单元安装在前围板的左下方，储物箱的上面和发动机舱电器箱的前面。
如果检测到问题，控制单元将点亮仪表板上的报警灯。
图5-8 ABS的液压单元液压泵和电磁阀液压单元，即液压执行器安装在发动机舱里，包含一些阀和一个液压泵。
这些阀有三个位置：压力增加，压力保持和压力下降。
当轮胎将抱死时，控制单元通知电磁阀保持压力。
如果轮胎保持抱死，控制单元将允许电磁阀降低压力直到轮胎开始转动。
控制单元让电磁阀开始建立压力从而开始另外一次循环。
液压泵送回当压力下降时来自制动轮缸的制动液。
液压泵被设计成能够保持两个制动回路相互独立。
在ABS工作期间，在制动踏板上能感觉到脉动，并且液压单元会发出嘀嗒声。
这是正常的，告知操作人员ABS在起作用。
5.4.2 工作原理ABS系统有很多不同的种类和控制算法。
我们将讨论其中一个比较简单的系统是如何工作的。
控制器全时监测轮速传感器的状态，等待超出寻常的车轮降速。
在某个车轮抱死之前，它将经历一个快速降速。
如果放任不管，车轮将比任何车辆可能的速度快得多的速度停止转动。
在理想状态下，它将使一辆车从60英里/小时（96.6公里/小时）到停下只需5秒钟。
但是抱死的车轮在小于1秒内就会停止转动。
ABS控制器知道这样一种快速的减速是不可能的，所以它降低制动器压力直到车轮加速，然后再次增加压力直到车轮降速。
在车轮速度发生明显改变之前，控制器就完成这些动作。
结果就是车轮以与车辆相同的速度慢下来，制动器控制车轮处于抱死的临界点。
这给了制动系统最大的制动力。
当ABS在运行时，制动踏板上将有脉动的感觉，这来自于电磁阀快速的打开和关闭。
有些ABS系统能每秒钟完成多达15次的循环。
5.4.3 防抱死制动的类型防抱死制动系统根据制动器的类型采用不同的方案。
我们根据通道数—即多少电磁阀被单独控制—和轮速传感器个数来进行分类。
四通道四传感器ABS这是最好的方案。
在所有四个车轮上都有一个轮速传感器和一个独立的电磁阀。
基于这种配置，控制器单独监测每个车轮以确保它获得最大的制动力。
三通道三传感器ABS这种方案通常安装在配备四轮ABS的皮卡上，每个前轮一个传感器和一个电磁阀，而两个后轮共用一个电磁阀和一个传感器。
后轮上的轮速传感器安装在后轴上。
这种系统对前轮单独控制，所以它们可以获得最大的制动力。
然而，后轮是一起监控的，它们在ABS控制后轴之前一起趋于抱死。
这种系统可能使得一个后轮在制动时抱死，从而降低制动效果。
一通道一传感器ABS这种系统通常安装在配置后轮ABS的皮卡上，它有一个电磁阀控制两个后轮和一个安装在后轴上的轮速传感器。
这种系统的工作过程与三通道系统的后轮控制相同。
后轮一起被监控，在ABS介入之前一起趋于抱死。
这种系统也可能使得一个后轮在制动时抱死，从而降低制动效果。
这种系统很容易辨认。
通常有一条制动管路穿过一个T形件到两个后轮。
你可以通过寻找接近后桥壳上的差速器处的电器连接找到轮速传感器的位置。
5.5 Tractor and Truck Air ABS 牵引车与货车气压制动ABS系统ABS控制单元（ECU）是控制气压ABS系统的电子模块。
为了测量串联桥货车的两个前轮和至少两个后轮的各自的车速，采用了可变磁阻式传感器。
为了控制提供给行车制动器气室的空气，从而防止车轮抱死，采用了电子控制ABS阀。
一种无挂车货车的ABS系统的电气和气压系统布置如图5-10所示。
图5-10 无挂车货车的气压ABS系统图5-11 带有自动牵引力控制的四通道ABS系统轮速传感器一般安装在前桥（转向桥）两端。
采用串联式后桥的货车常常只在一个后桥上装有轮速传感器（图5-11）。
依据货车的后悬架类型的不同，这两个后传感器或安装在前后桥或安装在后后桥的车轮端。
图5-11所示的这种四传感器、四ABS阀系统被称为四通道ABS系统。
其他的采用串联式后桥的货车可能在每个后桥的车轮端都安装有传感器，即总共有六个传感器和六个ABS阀。
所以这种ABS系统被称为六通道ABS系统。
ABS制动压力调节器（图5-10）（也叫作ABS阀，见图5-11）的作用是控制进入行车制动器制动气室的空气量，从而防止车轮抱死。
调节器内含有两个电磁阀（线圈），分别叫做进气电磁阀和排气电磁阀。
这两个电磁阀控制着调节器内的进气阀和排气阀（见图5-12）。
所绘出的调节器是一种调节阀与继动阀的组合体。
现代货车的调节器一般都在竖直方向上与货车行车制动气室供气管路串联连接。
图5-12 气压制动ABS制动压力调节器继动阀总成给调节器的常开进气电磁阀通电会切断进入各自行车制动气室的空气流。
那么，给常闭的排气电磁阀通电会使行车制动气室的部分压缩空气经过调节器的排气口被放到大气中。
这样会降低将要抱死的车轮的制动力。
ABS ECU根据需要对这些电磁阀进行控制，从而防止了车轮抱死。