Practical advise: How to decarbonise the engine — КиберПедия 

Общие условия выбора системы дренажа: Система дренажа выбирается в зависимости от характера защищаемого...

Состав сооружений: решетки и песколовки: Решетки – это первое устройство в схеме очистных сооружений. Они представляют...

Practical advise: How to decarbonise the engine

2017-10-16 828
Practical advise: How to decarbonise the engine 0.00 из 5.00 0 оценок
Заказать работу

Carbon deposit accumulates in the engine due to the burning of petrol in the cylinders. Assuming that a car does 40 miles to the gallon of petrol and covers 40,000 miles per year, 1,000 gallons of fuel will be burned in the engine each year. Obviously this must leave a considerable carbon deposit in the engine.

The effect of this accumulation of carbon is a general falling off in performance. To decarbonise the engine one removes the cylinder head. Overhead valve engines are roost common, and we shall deal with these first, noting the slightly different procedure* required by engines with overhead camshafts. Parts may be attached to the cylinder bead in one case and not in another. The principal things to do are:

Oram radiator. Remove valve cover, air cleaner and any other parts which have attachments to the cylinder head. Disconnect the radiator hose. Remove the carburetor. Then the petrol feed pipe and other attachments to the carburetor must be removed. In moving the exhaust and inlet manifolds, these need only be pulled off the studs, so as to rest clear of the head.

Take out the sparking plugs. Mark the leads so that they can be replaced correctly Remove the push rods. A good way is to turn the engine until the valves in the cylinder you are dealing with are closed. Fold a piece of cloth into a pad and place it over the Meter end mat works on the spring. By pressing heavily the spring if compressed and Hi sod of the rocker over the push rod lifts sufficiently to enable the rod to be pushed sideways and then removed. Each rod must be replaced, on reassembly, in the same position as it was when removed Therefore place all the rods in a safe place in the same order in which they were In the engine, so that no difficulty will arise on replacing. Then remove the rocker shaft.

The camshaft on some engines is chain driven and the chain must be removed from the chain wheel on the end of the camshaft before the head can be removed. Finally, remove the cylinder head itself. Be continued.

Nuts and Bolts

Nuts are hexagon shaped metal objects with a threaded hole through them so that they can be attached to bolts. Bolts are cylindrical objects with «threads» on the outside of them which enable them to be threaded into nuts. The hexagon shaped end classifies a «bolt». A «bolt» without an end is classified as a «lug» or «stud.»

Most bolts have what is termed as a «right-handed» thread. This is a spiraling thread. If you were inserting a right-handed threaded bolt into a threaded hole, you would turn it clockwise. Some bolts have «left-handed» threads. When inserting this type of bolt, you turn it counter clockwise.

There are many «grades» of nuts and bolts. Grades depend on the quality of the materials and the tolerances observed during the manufacture of the nuts and bolts. The ends of bolts and the faces of nuts are almost always marked with symbols denoting their quality standards. Unfortunately, in recent years it has become apparent through various government investigations, that unscrupulous individuals have been importing nuts and bolts with symbols printed on them that falsely denote a higher quality bolt. In other words, these individuals import and sell lead with gold stamped on it. This doesn't sound particularly dangerous, but in the cases of certain airplane and amusement park incidents, it has been proven that such a business deal, in conjunction with an innocuous object such as a nut or a bolt, can lead to tragedy.

Nuts and bolts are often separated by washers. Washers have many shapes and sizes, but serve one purpose. This purpose is to give the nut and the bolt a firm hard­ened surface for bedding against. The parts that you put together with nuts and bolts are usually not as strong as the nuts and bolts themselves. The washers allow the nuts and bolts to be folly tightened down, providing a wider area to spread out the force of the tightening. Washers keep the nuts and bolts from digging into the material when they are tightened. Washers shaped like a broken section of a coil are called «lock washers.» They are designed to prevent the nut from rattling loose.

«Allen» bolts have socket heads, or a recessed hexagon shaped hole in the top. You need Allen keys or wrenches to tighten or loosen the Allen bolts.

 

 

LESSON #2

CAR BODY

The body shell is a fairly complex assortment of large steel sections. These sections have been stamped into specific shapes which make up the body of your car. These parts are designed to do many jobs at once; protect the occupants from the elements and in collisions, provide solid mounts for all other systems, and to slice through the air with minimal resistance. The body also has one other job which is usually important to the owner... it has to look good!

 

Although the zillions of parts that make up a car are all very important, it is also important that the car's body be able to make riding in a car bearable for you. Early cars were so uncomfortable to ride in. The body and the suspension system now give us a smooth ride, and cushion us from the jarring of the road. The idea is that the body of the car should go forward with as little up-and-down and side-to-side movement as possible.

Frame (Chassis) The frame provides a firm structure for the body, as well a good anchor point for the suspension system. There are two types of frames; integral frames or unibody and conventional frames.

A conventional frame is basically a «one-piece» frame, or two «one-piece» frames fastened together. The frame is extremely rigid in order to keep all the other parts of the car in perfect alignment. The manufacturer takes this type of frame and attaches all the other parts of the car to it, like the way a sculptor starts with a wire frame to build his sculpture on and give it shape. To keep things smooth, rubber insulator blocks, or «pads» are placed between the frame and the other car parts. Because the conventional frame is so important to the structure of your car, (without it, your car would be a pile of doors, hoses, seats, wires and metal) it is usually constructed of heavy steel and welded or cold riveted together. Cold riveting keeps the rivets from shrinking.

The integral, or unibody, frame is just the opposite. With this type of frame, the body parts are used to structurally strengthen the entire car, and all of the sections are welded into one piece. Sometimes the parts of the body and the suspension system are attached and reinforced. Also, some unibody frames have partial front and rear frames for attaching the engine and suspension members.

Hood. The car's hood is another type of door. It also consists of an inner and an outer panel. The inner panel provides strength. The outer panel is just a metal cover, or «skin». The underside of the hood is often covered with a sound-absorbing material. Some high performance cars have openings in the hood to allow the engine to «breathe» easier. «Hood scoops» are used to channel outside air directly to the air filter, which gives improved performance and efficiency.

Trunk Lid. The trunk lid is another type of door. It consists of an inner and an outer panel. The inner panel provides strength. The outer panel is just a metal cover, or «skin».

Rocker Panels. A rocker panel is a three or four inch piece of metal that runs along I the bottom of the car body underneath the doors. Rocker panels are usually coated with a рек proof protectant which rubberizes the exterior surface before the car is painted. If you have mud flaps behind your wheels, this protects your rocker panels, as well as your fend­ers and your doors. Rocker panels are often made of chrome plating, and enhance the car.

Wheel Well. The wheel well is either plastic or metal. Metal wheel wells are usu­ally part of the body shell. Metal wheel wells strengthen the structure of the car because of their shape, and because they are strongly welded to the body shell. Most rear wheel wells are made of metal. Wheel wells are coated with a rock-proof, rubberized coating underneath, in order to prevent the rocks kicked up by the wheels from damaging the metal and making a lot of noise when they hit.

Often the front wheel wells are made of plastic. This is because it is harder to mount the engine with the front wheel wells in place. Plastic wheel wells can be removed, and make it easier to mount the engine during the manufacturing of the car.

Front Quarter Panel. The front quarter panel is composed of the body skin, or sheet metal, that runs from the front corner of the hood to the front of the door. It is usually a separate piece that is welded on in a few places. This makes it easy to replace if you get in a «fender bender.» Front quarter panels can usually be replaced relatively inexpensively. Some newer vehicles use a rubber-like plastic for the fenders, which al­lows small impacts to be absorbed without damage.

Windshield. In the 1930s many cars had hinged windshields that could be folded on the hood of the car or opened up. Today, most windshields are stationary. They are fixed in place with a weather-strip made of rubber. The strip has a groove on the inside and a groove on the outside. The inside groove holds the glass; the outside groove holds the metal rim of the windshield opening in place. The glass «floats» in a plastic sealant that is spread out between the edge of the glass and the frame of the windshield.

Windshields are made of laminated safety plate glass, which is a sandwich of glass and clear plastic. The plastic acts as a soft, protective barrier, keeping the glass in place, if it is struck during a collision. The glass sticks to the plastic to eliminate glass from flying around the interior and injuring someone.

Safety glass for windscreens was one of the first passive safety devices introduced into cars, but its use remains a controversial question. North America and Scandinavia favor a laminated glass, which consists of two sheets of annealed glass, separated by a layer of transparent plastic. In recent years, laminated glass has been improved by changes in the properties of the plastic interlayer. Research has demonstrated that this new laminated glass is about 4 times safer than toughened glass, but because it is more expensive, controversy continues as to whether or not toughened glass windscreens |should be banned by legislative action and replaced by laminated glass.

Recent developments have combined the benefits of both laminated and toughened material in that a laminated construction is used, but the sheet next to the inside of the is made of toughened glass.

Seats. There are basically two types of seats: bench seats or bucket seats. A bucket seat is a low, separate seat for one person. Bench seats are a continuous cushion and backrest across the width of the car (although some vans might have them running along the length of the van). Bucket seats are single units with a separation between the left and right seats.

Usually vinyl leather and fabric are used for upholstery. «Flat springs» are used for comfort. A flat spring is a piece of wire that is bent into a zigzag pattern. Both ends of the wire are attached to the seat frame, with additional lengths added every six inches. Foam padding is used to cover the flat springs.

The front seats ride on rails that are bolted to the floor. This arrangement allows eats to move backwards and forwards to suit the driver or passenger. The seat ad-justment lever is attached to a latch that fits into teeth along the rail. Moving the lever releases the seat, and allows the seat to move. At any point of the seat's movement, releasing the lever engages the latch with one of the teeth. Usually there is also a pull-spring; this draws the seat forward when the latch is released. The rear seat usually doesn't move, because it is secured to the floor of the car. Its backrest is attached to the partition between the passenger compartment and trunk.

Having an air bag and wearing an effective seat belt offers the best protection of all. Not only are you protected from frontal crashes by the air bag — you are also protected by the seat belt in all other types of crashes. The benefits of the three-point seat belts have been firmly established: over 50 % of fatal and serious injuries to car occupants would be avoided if all occupants wore their seat belts. Most states now have a law that both passengers and driver must have seat belts buckled while in motion. Those states which do not enforce a seat belt law for all passengers have an effective law for children under five years of age to be strapped in.

WORDLIST:

Frame рама; каркас

integral frame or unibody несущий или безрамный кузов

conventional frame кузов с несущим основанием, с рамой

suspension system система подвески

perfect alignment правильное расположение

wire frame проволочный каркас

pad подушка

hose патрубок, шланг

hood капот

sound-absorbing противошумный, звукопоглощающий

hood scoop воздухозаборник в капоте

trunk lid крышка багажника

rocker panel короб порога

rock proof protectant камне (щебне) защитное покрытие

wheel well колесная ниша

front quarter panel передняя часть кузова; крыло

fender крыло

fender bender легкое столкновение, ДТП

windshield ветровое (лобовое) стекло

weather-strip уплотнитель

windshield opening проём лобового стекла

plastic sealant пластиковый герметик

laminated safety plate glass ламинированное листовое стекло

annealed glass отожженное стекло

toughened glass закаленное (высокопрочное) стекло

bench seat нераздельное сиденье

bucket seat одноместное сиденье

upholstery обивка

flat spring плоская пружина

rail (зд.)направляющая салазок

latch защелка; фиксатор

air bag воздушная подушка безопасности

three-point seat belt трехточечный ремень безопасности

COMMENTARY:

protect the occupants from the elements and in collisions - защищать пассажи­ров от элементов конструкции кузова и во время столкновения;

 

provide solid mounts for all other systems — обеспечить прочные места для ус­тановки всех других систем;

to slice through the air with minimal resistance - рассекать воздух с мини­мальным сопротивлением; обеспечивать хорошую обтекаемость;

EXERCISES:

I. Translate the following sentences into Russian:

a) There are two types of frames: integral frames or unibody and conventional

frames.

b) The frame is extremely rigid in order to keep all the other parts of the car in

perfect alignment.

c) Because the conventional frame is so important to the structure of your car, it is

usually constructed of heavy steel and welded.

d) Sometimes the parts of the body and the suspension system are reinforced.

e) The underside of the hood is often covered with a sound-absorbing material.

f) A rocker panel is a three or four inch piece of metal that runs along the bottom

of the car body underneath the doors.

g) Some newer vehicles use a rubber-like plastic for the fenders, which allows

small impacts to be absorbed without damage.

h) Safety glass for windscreens was one of the first passive safety devices

mtroduced into cars.

i) The rear seat usually doesn't move, because it is secured to the floor of the car.

II. Explain and translate the following definitions of the car body elements:

A-pillar: The first set of structural roof supports at either side of the windshield. The next set of pillars, behind the front doors, is called B-pillars, and those behind the rear doors are called C-pillars. Some limousines and station wagons have D-pillars.

Boot: Box, one-, two-, three-: Body morphology is often described in terms of one-box, two-box and three-box. A one-box body usually refers to a van, whose body looks like one big box. A station wagon or something like the VW Rabbit qualifies as a two-box body, the hood being one box and the cabin the second. And a three-box body is usually a conventional sedan or coupe: hood, cabin and trunk. Also called «one-, two — and three-shape.

Boattail: The rear of a car body shaped like the upside-down prow of a boat. Body in white: The finished but unmounted and unpainted body. It's called «in the whiter because the original protective undercoat was white or light yellow.

Dashboard: In very early cars, an upright wooden or metal panel at the front of the body. This was a holdover from days when the dashboard literally shielded the carriage from the horse and road splash. In more modern cars, the word «dashboard» is sometimes used interchangeably with the more correct term, instrument panel,»

Greenhouse: That part of the car body above the beltline that includes the roof,

pillars and glass.

Ground clearance: The distance from the lowest point on the chassis, excluding

wheels, to a level road surface.

Quarter panel: That part of a car body side comprising the rear fender from the

rear door opening back.

Radiator grille: The protective, often ornamented area or structure ahead of the

engine radiator, usually at the front center of the body.

Wheel cover: An ornamental, protective metal disc that covers an entire wheel, as

opposed to a hubcap which covers only the center.

 

III. Translate the following information into English:

Кузов легкового автомобиля служит для размещения агрегатов и узлов сЩ автомобиля и транспортировки пассажиров и багажа. По конструкции эти ку| делятся на каркасные и бескаркасные. У кузова с несущим основанием натр]

распределяется между кузовом и рамой.

При движении автомобиля с большой скоростью значительная часть мощности двигателя расходуется на преодоление сопротивления воздуха. Для уменьшения сопротивления кузову предается обтекаемая форма.

По конструкции кузова легковых автомобилей могут быть тpexoбъемные, двухобьемные и однообьемные. У трехобьемного кузова имеется три отсека: для двигателя, пассажиров и багажа. Такой кузов может быть с двумя или четырьмя боковыми дверями и называется седан. Двухобъемный кузов с двумя или четырьмя боковыми дверями и задней дверью — хетчбек (комби). В основном все детали кузова изготовляются из тонкой листовой стали с помощью штамповки.

 

IV. Translate the following information into Russian:

Some automobiles used a compromise design with a partial monocoque combined a subframe carrying the front end and power train. The intention was to provide some of the rigidity and strength of a anybody while easing manufacture, although the results weremixed, in large part because the power train subframe contained the greatest single portion of the vehicle's overall mass, and thus movement of the subframe relative to the rest of body could cause distortion and vibration. Subframes or partial sub frames are still sometimes employed in otherwise monocoque construction, typically as a way of isolating the vibration and noise of powertrain or suspension components from the rest of the vehicle.

In automobiles, it is common to sec true monocoque frames, where the structural members around the window and door frames are built by folding the skin material several times. In these situations the main concerns are spreading the load evenly, having no holes for corrosion to start, and reducing the overall workload. Compared to older techniques, in which a body is bolted to a frame, monocoque cars are less expensive and stronger.

Monocoque design is so sophisticated that windshield and rear window glass now of­ten make an important contribution to the designed structural strength of automobiles.

 


Поделиться с друзьями:

Состав сооружений: решетки и песколовки: Решетки – это первое устройство в схеме очистных сооружений. Они представляют...

Типы оградительных сооружений в морском порту: По расположению оградительных сооружений в плане различают волноломы, обе оконечности...

Типы сооружений для обработки осадков: Септиками называются сооружения, в которых одновременно происходят осветление сточной жидкости...

Механическое удерживание земляных масс: Механическое удерживание земляных масс на склоне обеспечивают контрфорсными сооружениями различных конструкций...



© cyberpedia.su 2017-2024 - Не является автором материалов. Исключительное право сохранено за автором текста.
Если вы не хотите, чтобы данный материал был у нас на сайте, перейдите по ссылке: Нарушение авторских прав. Мы поможем в написании вашей работы!

0.081 с.