Historical studies of the development of the form of the bus. Bus bodies What does a bus consist of

15.07.2019

Fuel system

They call cars designed to carry passengers and having 9 or more seats. There are small and large capacity. Large-capacity vehicles with 22 or more seats are divided into classes: urban, intercity, tourist. Suburban buses that are not allocated to a separate class have signs of urban and intercity types.

Small capacity cars are divided into 2 classes, designed to carry seated and standing or only seated passengers. Internal equipment passenger cars may be modified to convert them to specialized transport, designed to transport children, emergency teams, use as mobile headquarters and laboratories, to provide funeral services.

What is the bus made of?

There are several types of bus bodies: bonnet, wagon, one and a half and two-story. Most of the bodies are wagon type. General layout buses can be different, but several main parts of the technical device can be distinguished.

Engine

It makes technology move. Runs on petrol, diesel or gas fuel.

There are several options for the location of the engines:

Front - in buses wagon type. Disadvantages - the presence of gas in the cabin, noise.
Under the floor - in the wheelbase area. Advantage - a flat floor in the cabin, cons - small ground clearance, the impossibility of using such equipment in poor road conditions.
Behind. The location of the engine in this case can be horizontal or vertical, along or across the axis of the vehicle. Minus - the need for a non-standard rear axle.

Chassis

The chassis includes: chassis, control mechanisms, transmission.

Transmission device:

Clutch. In some buses, its functions are performed by a torque converter and hydromechanical box gears.
Transmission. Provides the ability to change the traction force on the front wheelset, give reverse, keep the engine running while the vehicle is standing still.
Cardan and main gear. Cardan transmission transmits torque from the gearbox to main gear, from which it is transmitted to the semiaxes.
Differential. Thanks to the differential, the wheels rotate at different speeds when cornering.
Half shafts. Transfer torque from the differential to the drive wheels.

Running gear composition:

the base of the carrier body;
front and rear axles;
wheels;
springs;
shock absorbers.

Control mechanisms - steering and brake with foot and hand drive.

Body

It may include steel welded tubular frames, aluminum non-welded, mixed aluminum-steel, partially welded frames. Modern buses are mainly manufactured using steel profiles. For sheathing, sheet metal is used from durable aluminum alloys or cold-rolled low-carbon steel capable of cold stamping.

Doors - front and rear - can have a different number of wings: from one to four. The pneumatic mechanisms that open and close the doors are controlled by a crane located in the driver's cab. The windows located on the side have sliding elements, the rear windows are blind. Glasses - the tempered polished, bezkolochny. For facing the ceiling part, sheet layered polymeric materials are used. The floor is made of steel or aluminum sheet, moisture resistant baked plywood. Top have rubber mats with non-slip surface.

The car body is the most
expensive car part.

The supporting structure of the bus, the body frame of which consists of rigid frames and stringers connecting them, forms a structure having high performance rigidity (frame body).
Due to the presence of passenger doors power circuit the bus body is usually not symmetrical, and to give the entire structure the necessary rigidity, the doorways are reinforced around the perimeter with additional details.
The base of the bus body, as a rule, is made in the form of an independently operating system, on which the body frame is installed, which in this case perceives a relatively small load. Such a base is called a carrier or integral. The integral base allows you to make changes to the body structure and simultaneously produce buses with various bodies. space between separate elements the integral base is used to accommodate fuel tanks, pneumatic system receivers, batteries and other devices, and on intercity and tourist buses - to accommodate luggage.

The body of the bus is a complex structure, which consists of about three thousand parts. The mass and cost of the body make up more than half of the mass and cost of the bus.
The type of bus body is determined by its purpose, layout and design.
Depending on the destination, the bodies of buses are divided into urban, intercity, tourist and special.
Bodies of city buses are subdivided into bodies of intracity and suburban buses.
bodywork city buses have two rows of seats, a central aisle of considerable width and storage areas for passengers at the door. They are characterized by a small number of seats, low floor level, as well as wide passages and doors. All this ensures the convenience, speed and safety of entry, passage and exit of passengers. Low level floor also allows you to increase the height in the aisle and the volume of the passenger compartment, which increases the comfort of the body.
The bodies of suburban buses, unlike intracity buses, have large quantity seating, fewer and smaller doors and a small storage area for passengers.

Bodies of intercity buses are designed for year-round passenger traffic on long distance. To increase the comfort and convenience of passengers, these bodies have, adjustable seats, improved ventilation, sinking, radio-equipped passenger compartment and luggage compartments. Some bodies of intercity buses may have separate household premises - a wardrobe, a canteen, a toilet, etc. For bodies of intercity buses, it is typical high level floor, four-row seating and the presence of one door in front. The high level of the floor allows you to place roomy trunks under the floor, allows any location of the engine and transmission, improves comfort due to better visibility and isolation of the passenger compartment from noise, gases, dust, etc.
Bodies of tourist buses are divided into bodies of normal, increased and high comfort.
Bodies of tourist buses of normal comfort are designed for sightseeing trips of people over short distances. Therefore, they have the same design as the bodies of commuter buses. However, they are equipped with an additional seat for the leader of the tourist group, have a loudspeaker installation and other additional equipment.
Bodies of tourist buses of increased and high comfort are designed for year-round sightseeing trips of people over long distances. In this regard, they have the same design as the bodies of intercity buses, but differ from them in the presence of an additional seat for the leader of the tourist group, as well as a loud-speaking radio installation and other additional equipment.
The bodies of special buses are designed for placement and transportation various equipment(medical, laboratory, etc.), as well as equipment for specific purposes (library, shop, etc.). Special bus bodies are made on the basis of conventional bus bodies with the necessary alteration and equipment in accordance with the purpose.
Depending on the layout, bus bodies are divided into bonnet bodies and wagon-type bodies.
Bonnet bus body is designed for installation on a standard chassis truck. This body has a special engine compartment, which is located outside the passenger compartment and forms separate body shapes, in this case the bus body is two-volume.
The bus body of the wagon type is one-volume. In it, the engine compartment is combined with the passenger compartment - and can be located in front or behind. The wagon-type body has overall dimensions coinciding with overall dimensions bus, it provides best use bus and passenger area.
Greatest Application on modern buses received a wagon-type body. The body has a rigid structure and consists of a frame - outer cladding, inner floor cladding, windows, doors, etc. Inside the body are the passenger and driver seats.
The frame is the main part of the bus body. It consists of a base, sidewalls, roof, front and rear parts. The body frame is often made of welded steel pipes rectangular section. Materials for - the manufacture of the frame are also steel and aluminum profiles.
The outer lining of the body is made of steel sheets with a thickness of 1-1.2 mm or aluminum sheets with a thickness of 1.5-2 mm. Sometimes it is made of plastic panels reinforced with glass cloth or fiber, 2-3 mm thick, which are superior to metal panels in terms of strength, heat and sound insulation, as well as maintainability.
The floor of the bus body is made of bakelized plywood 10-15mm thick, single sheet (1.2-1.5mm), aluminum sheets (3-4mm) and corrugated aluminum panels.
Bus doors are usually made separate for passengers and the driver. The front doors for passengers are often made three-leaf or four-leaf, and rear doors- four-leaf. Doors for drivers are usually made single-leaf. Three-leaf and four-leaf doors for passengers are opened and closed using pneumatic mechanisms controlled by the driver.
Bus windows (wind, side, rear) are different in shape and design. side windows often made rectangular with sliding or folding windows. The wind and rear windows are deaf, they have curved glass.
Seats in buses for passengers and drivers have a different design. Passenger seats can be either adjustable or non-adjustable. Non-adjustable seats are used in city buses, and adjustable seats are used in intercity buses. The seats of long-distance buses are made in the form of half-sleeping chairs with a variable angle of inclination of the back, as well as pillows and backs of increased softness. The driver's seat is usually made adjustable in the longitudinal direction, in height and in the angle of the backrest. It is often equipped hydraulic shock absorber rum, which dampens seat vibrations that occur when the bus moves over bumps in the road.

Articulated buses- one of the expressive strokes transport system modern megacities. The history of the development of this species public transport is inextricably linked with the improvement of the design of the hinge assembly connecting the front and rear sections of the road train. We studied some of the features of modern bus "crossings", in which traditional mechanics are supplemented with hydraulics and electronics.

The increase in intracity passenger traffic in the middle of the last century made bus manufacturers think about increasing the capacity of rolling stock. One of the solutions was trailer bus. It is known that not only bus operators, but also trolleybus manufacturers worked on such projects. However, the narrow streets of European cities required not only roomy, but also maneuverable vehicles. Therefore, the next step in the evolution of buses is especially big class became two-section machines, in which the head and tail bodies are combined corrugated cover, simultaneously protecting the articulation zone from the impact external environment. And since the articulation mechanism directly affects such operational qualities of the road train as handling, stability and maneuverability, all further steps to change the layout of the chassis entailed the complication of the design of the connecting link. Today, the assembly, which includes a swivel joint, a damping system, an on-board communications "conductor" and other elements, is a complex electronic-hydraulic device at a cost comparable to a power unit or hydromechanical transmission.

Pull or push?

At first, "accordions" of the so-called "pulling" design were considered classics of the genre. Horizontal engine, located under the floor at the head of the bus, set in motion the second axle of the three available. At the same time, the intersection joint worked like a truck towing device, and the trailer axle was a thruster. For example, according to this scheme, the Hungarian buses Ikarus-280 and Ikarus-283, plying on the capital's routes, were built. Note that some experience in the design of "accordions" according to the pull scheme has been gained and domestic producers. So, in the 90s, Yakhrovsky was engaged in the manufacture of such samples. bus factory(YaAZ-6211) and Moscow SVARZ (SVARZ-6240).

The simplicity of the "classic" designs was accompanied by a number of disadvantages: poor accessibility power unit for service, elevated level noise in the cabin, and most importantly - the high level of the floor: passengers had to overcome several steps. Therefore, in parallel, another option was proposed: to place the engine in the tail section, leaving the middle axle as the leading one. But such technical solution greatly complicated the design of the bus chassis. First of all, certain obstacles were created by the need to transmit torque through the "bend", which means that manufacturers needed to carefully work out the place of passage cardan shaft through the junction. In addition, for a fuller load on the drive axle, in some cases it was necessary to separate the gearbox from the engine, installing it in front of the bus. It is also important that the use of such a design led to disunification with the basic (single) model. The only significant plus of buses with an average drive axle and rear engine- no need for complex mechanism folding control. Among the examples of the implementation of this unusual layout, one can note the "accordion" MAN SG240H, several samples of this model, until recently, worked in the urban transport system of St. Petersburg.

The opportunity to start manufacturing buses according to an alternative - “pushing” scheme appeared after entering the market special systems to protect the hitch from folding. One of the first innovative articulation unit with hydraulic system damping brought to light German company FFG Falkenried, patent dated 1975. Two years later, the license for the production of these units was purchased by by Mercedes-Benz, which was then able to build articulated buses using "transitions" own production. Later, the rear-engine layout with a trailer axle drive became a priority for other major bus manufacturers, including MAN, Volvo, Solaris, Irisbus.

In Russia, the first serial articulated bus with rear location The engine was released in 1995: the AKA-6226 "Rossiyanin" model, produced at the Golitsinsky Bus Plant, was built on the basis of the Mercedes-Benz O405G. The Likinsky bus plant put on the conveyor a two-section LiAZ-6212 with an “active” trailer in 2002, later its low-floor version appeared with the index 6213. Despite the fact that the factory workers had some experience in developing their own articulation unit, in both cases it was decided give preference to a purchased product - a kit from Hubner. By the way, the Ukrainian LAZ went the same way when building the A-292 City model.

I must say that today most bus manufacturers use purchased folding units for the rear-engine performance of "accordions". Accordingly, the production of articulation systems can be considered as a separate and narrowly focused type of business. The range of complete assemblies offered on the market, from standard to specialized, is able to satisfy the most stringent customer requirements and take into account all the nuances of the layout.

Hidden in the details

Among the damping systems most in demand today is the Hubner HNGK 19.5 product. This assembly is used in both high-floor and low-floor versions of buses and is almost maintenance-free. The hinge is based on two massive flat parts, united by a central bearing, which, in fact, makes it possible to turn the trailer about the vertical axis (angle of deviation +/- 54 degrees). Freedom to swing in the longitudinal plane
(+/- 11 degrees) provides a pair of silent blocks. The question of elasticity is solved in a similar way for transverse slope(twisting of the trailer relative to the tractor, for example, when driving on a rough road or a malfunction of the suspension air spring). True, this angle in the "pushing" scheme is small and is no more than 2 degrees in each direction.

The key elements of the mechanism responsible for the mutual position of the tractor and trailer are two independent horizontal hydraulic cylinders. Acting like a controlled suspension damper, hydraulics on command electronic block can change the resistance to movement of the rods. Thus, a decrease in pressure in the corresponding cavities of the left and right cylinders in response to turning the steering wheel will allow the composition to “bend” into the right side when maneuvering, and for the bus to move straight, it is enough to block both rods in the middle position. The electronics provides stepless damping of the assembly, while the microprocessor processes data such as movement speed, movement relative to the vertical axis and the pressure in each cylinder to evaluate external factors. Information can be transmitted in analog or digital form (via CAN bus). If necessary software allows you to fit into the operation of the power unit or brake system, simultaneously applying warning signal driver. It is important to have in the system emergency mode damping, which allows you to stabilize the articulation in the event of a failure in the operation of one of the cylinders or a power failure.

Identical in functionality, but peculiar in design, the HNG 15.3 high-strength assembly, designed for use in "accordions" with increased axial load(including hybrid and gas). It has three silent blocks and a more load-bearing bearing. But the systems offered for completing models with a “pulling” scheme differ in the most simple device: the main element is a ball joint. It does not require the use of dampers, so the products are characterized by low weight and low cost.

Far from the last importance in articulation systems is attached to laying communications (electrical, pneumatic, hydraulic) between the tractor and the trailer. There is also a whole arsenal of technical solutions. For example, in the version of a low-floor bus, there is a certain margin of installation space at the top and there is practically no possibility of placing communications under the articulation mechanism. That is why electrical and pneumatic lines, as a rule, are laid under the "roof" or mounted in the sidewalls. In the first case, a flexible chute is used for fixation, which can change the arc radius depending on the folding angle. And in alternative the intermediate support is a vertical rim located in the central part of the articulation. This ensures that hoses and cables are not kinked or unacceptably bent.

Finally, the most voluminous expressive component of the articulation system is the “fabric” intersectional corrugation. It is made from flexible synthetic material with folded aluminum edging. Traditionally, such components were performed in gray tones. However, today the concept comes to transport operators that the “accordion” cover is not only a reliable screen, but also an integral element of stylish design. In response, the developers are bringing to the market novelties that allow each bus to give a unique individual look. Bus passengers, for example, will love the translucent version offered by Hubner, which allows additional illumination of the passenger compartment. daylight. Another modern version- a multi-color picture on the outside, changing depending on the position of the folds, can be a certain element of the carrier's corporate style and a means of attracting attention. Such an “animation” works especially effectively on multi-section buses, which, by the way, are gaining more and more popularity among transport companies due to the largest passenger capacity.

One way or another, the optimization of articulated bus designs continues. One of the promising tasks facing designers is to reduce the height of the damping device. In some cases, this will allow bus manufacturers to get away from the problem of partial low floor space.

By the way

Last year, the bus department of the Minsk Automobile Plant expanded the family of city buses new model- articulated bus of extra large capacity MAZ-205. The low-floor bus is designed according to the pulling scheme - with a driving middle axle. The design has interesting feature: the engine, located in the tractor, is not placed horizontally under the passenger compartment floor, but vertically to the left - in the so-called shaft. This technical solution made it possible, firstly, to reduce the cost of the design by abandoning the articulation unit imported production, and secondly, to improve the handling of the bus on slippery areas roads, which is especially important when operating in urban conditions. By the way, this is why buses with an engine in a tractor are still offered on the market by other manufacturers, including the Belgian Van Hool and Jonckheere.

The book tells about the device and principles of operation of nodes, mechanisms and units of buses. Models of GAZ buses are presented. ZIL. LiAZ and others are widespread in Russia.
The textbook is designed to train car drivers Vehicle category "D".

Types of engines, general arrangement and principle of operation.
In the engine internal combustion the potential thermal energy of the fuel is converted into mechanical work. Complete process such a transformation is called a working cycle, consisting of a certain number of cycles.

Tact - part of the work cycle that takes place in the process of moving the piston from one extreme position into another.
According to the organization of the working cycle, internal combustion engines are divided into two-stroke and four-stroke. Currently, four-stroke engines are overwhelmingly widespread.

According to the method of ignition combustible mixture engines can be spark ignition (gasoline or gas) or compression ignition (diesel). Extra-small, small and medium-sized buses can have either gasoline or gas, or diesel engines, large and extra large buses are equipped only with diesel engines.

According to the type of fuel used to form a combustible mixture, gasoline, liquefied or compressed can be used. natural gas, diesel fuel.

Content
Chapter 1. Basic concepts and definitions 5
1.1. Classification of buses according to international and domestic standards 5
1.2. General device buses and their layout options 6
1.3. Bus maintenance basics 13
Chapter 2. Engine 16
2.1. Types of engines, general design and principle of operation 16
2.2. crank mechanism 24
2.3. Timing mechanism 35
2.4. Cooling system 41
2.5. Lubrication system 47
2.6. Power supply system for petrol and gas engines 53
2.7. Diesel engine power system.85
2.8. Ignition system 98
2.9. Exhaust system 108
2.10. Maintenance (TO) of the engine and its systems 110
Chapter 3. Electrical equipment of buses 112
3.1. General information 112]
3.2. Rechargeable batteries 113
3.3. Generators and control systems 116
3.4. Starter 120
3.5. Auxiliary electrical systems 127
3.6. Lighting system 129
3.7. Light and sound signaling 138
3.8. Instruments and internal alarms 141
3.8. Maintenance of electrical equipment 146
Chapter 4. Chassis of buses 147
4.1. Transmission. General arrangement, purpose and layout 147
4.1.1. Clutch 149
4.1.2. Mechanical boxes gear 157
4.1.3. Hydromechanical transmissions 164
4.1.4. cardan gears 181
4.1.5. Drive axles 184
4.1.6. Maintenance of transmission units 189
4.2. Bus suspension, general purpose and device 191
4.2.1. Front suspension of buses 193
4.2.2. Rear suspension buses 205
4.2.3. Suspension maintenance 210
4.3. Steering buses 211
4.3.1. General purpose and operating principles 211
4.3.2. Steering of small buses 211
4.3.3. Steering big buses 223
4.3.4. Steering features of articulated buses 224
4.3.5. Steering maintenance 227
4.4. Brake control of buses. General purpose, drive types 227
4.4.1. Purpose of the braking system. Types of braking system 227
4.4.2. Brake control of extra small and small buses 230
4.4.3. Brake control of large city buses 249
4.4.4. Maintenance brake control 265
Chapter 5. Carrier systems of buses 267
5.1. Bus frames 267
5.2. Bus bodies 267
5.3. Heating and ventilation of the passenger compartment 280
5.4. Body maintenance 287
Chapter 8. Wheels and tires 289
Chapter 7 Operating materials and their consumption rates 295
7.1. Fuel 295
7.2. Lubricants 296
7.3. Technical liquids 303.

Free download e-book in a convenient format, watch and read:
Download the book Arrangement and maintenance of buses, Textbook for the driver of vehicles of category "D", Selifonov V.V., Biryukov M.K., 2004 - fileskachat.com, fast and free download.