The structure (layout) of cars (VAZ-2109)

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VAZ-2108, VAZ-2109 cars and modifications based on them are primarily front-wheel drive passenger cars. Their layout is characterized by the front and transverse arrangement of the power unit (engine assembly with gearbox, final drive and differential) From it, torque is transmitted to the front wheels using shafts of unequal length, at the ends of which constant velocity joints are installed. The front drive wheels create high stability of the car against lateral skidding. The coincidence of the direction of action of the traction force on the front drive wheels with the direction of movement of the wheels provides the car with good controllability, maneuverability and cross-country ability, especially on slippery and icy roads.



The front-wheel drive layout, compared to the rear-wheel drive, allows for a more complete use of the length of the car and a reduction in its weight, making the interior and seating of the driver and passengers more comfortable. The useful volume of the car increases without increasing its dimensions. This is explained by the fact that there are no intermediate transmission links (cardan transmission, rear axle) and therefore eliminates the need for a transmission housing that takes up significant space in the footwell of rear-wheel drive vehicles and a large floor tunnel for the driveshaft. On front-wheel drive vehicles, the small floor tunnel houses only the exhaust system and the parking brake actuator.

The rear part of the car is also very compact. The fuel tank 20 is located under the rear seat, and the spare wheel 14 is in the niche of the trunk floor. Thanks to this, a significant volume of the luggage compartment was obtained.

The wedge shape of the body improves its aerodynamic characteristics, i.e. reduces air resistance when the car is moving. This is facilitated by the smoothed outer surfaces of the body, the large slope of the front and rear windows, as well as the smooth transition of the outer surface of the front bumpers into the shaping surface of the body.

Low aerodynamic drag, a new more economical engine, and the installation of new tires with reduced rolling resistance have resulted in low fuel consumption. The reduction in fuel consumption is closely related to the reduction in vehicle weight, since each kilogram of the vehicle's own weight costs approximately 20 g of fuel per 100 km of travel. The reduction in weight was facilitated by both the front-wheel drive layout of the vehicle (absence of heavy rear axle, cardan transmission), as well as a rational power structure of the body, the wide use of lightweight plastics and new construction materials.


Bumpers, various covers, heater parts, interior and trunk trim are made of plastic. The weight of plastic parts reaches 80 kg. The radiator and many parts of the gearbox are also made of aluminum alloys, which also allowed to reduce the weight of both the power unit and the car as a whole.

Engine

The car has a new engine, specially designed for transverse placement, for which its length has been reduced as much as possible. Selection of the optimal combustion process, valve timing, combustion chamber shape and gas channels - all this allowed to increase the compression ratio in the engine to 9.9. In combination with a new carburetor and contactless ignition system, this improved the efficiency of the engine.

The engine cooling system is a closed liquid type with forced circulation of liquid. The coolant pump of the original design is located in the front part of the cylinder block and is driven by the camshaft drive belt. The radiator is aluminum with plastic tanks.

The engine lubrication system has an original oil pump with internal gears. The pump is located at the front end of the crankshaft and does not have any additional drive. The oil filter is unified with the one used in the car VAZ-2105.

The fuel system is equipped with a fine fuel filter. To stabilize the pressure at the carburetor inlet, a return fuel line is provided to drain excess fuel back into the tank. A new carburetor is used, providing economical mixture formation in various engine operating modes.

The engine ignition system is electronic contactless. The contactless sensor in the ignition distributor sensor is based on the Hall effect, the ignition advance angle correction is mechanical due to the centrifugal and vacuum regulators. The switch on high-voltage transistors. The electronic ignition system increases the stability of the engine at low speeds and improves its efficiency.

Transmission

The car's transmission is simple, compact and reliable. It is combined into a single unit consisting of a clutch and a gearbox with a main gear and differential. The compactness of this unit allowed the power unit to be positioned across the car and the front wheels to be driven directly from the gearbox, which allows the most efficient use of engine power and reduced fuel consumption. The transmission has retained the high reliability and performance of previous models and at the same time the overall weight and noise level have been reduced.

The gearbox is made according to a two-shaft scheme. All forward gears are synchronized. Most gearboxes are produced in a five-speed version, but production of four-speed gearboxes is also envisaged. The use of low-viscosity motor oil in the gearbox reduces losses during torque transmission and makes it easier to start the car in winter.

The clutch is single-disk dry with a diaphragm pressure spring and with increased wear resistance of friction linings. The clutch drive is cable, which makes it simpler. There are no gaps in the drive, and the clutch release bearing is constantly pressed against the diaphragm spring with a force of 5-7 kgf.

Wheel suspension

The cars use a fundamentally new suspension of 27 front wheels of the "swinging candle" type, also called the "McPherson" suspension after its inventor. The spring in such a suspension is located actually above the axis of the turning device and is loaded less than in a double-lever type suspension. There is only one lever in the suspension - the lower one. The suspension is compact, has a small mass, a large wheel travel and is more elastic.

The front suspension roll arm is negative, since the intersection point of the wheel pivot axis with the road surface is outside the outer part of the vehicle. This helps to increase vehicle stability during braking, when the left and right wheels have different grip on the road surface, and also reduces the effect of traction forces on steering.

The front suspension is well matched with the rear suspension 19 of two longitudinally swinging levers connected to each other by a crossbar that acts as a stabilizer. The elastic element in the rear suspension, as in the front, are coil springs.

Steering

With the transverse arrangement of the power unit and the front wheel suspension of the MacPherson type, the steering control 25 with a rack steering mechanism is well assembled. It does not require intermediate levers, it is compact and simple in design. The steering rods are attached to the central part of the steering mechanism, which made it possible to simplify the design of the steering drive, since only two ball joints are used. This type of steering provides a small force on the steering wheel (9-12 kgf).

Brake system

The brake system has effective front disc brakes and rear drum brakes. The brake drive is vacuum-boosted, dual-circuit, with diagonal circuit division. One circuit serves the brake mechanisms of the left front and right rear wheels, the other - the right front and left rear wheels. This division of circuits is the simplest and meets the requirements for brake efficiency in the event of failure of one of the circuits, when the car maintains a straight-line direction of movement and no more than 50% of braking efficiency is lost.

Body

The body is a three-door, two-volume hatchback type. It combines the versatility of a cargo-passenger body with the sweeping lines of sports cars. The luggage compartment is separated from the passenger compartment by a folding plastic shelf installed behind the rear seat. The body is easily transformed into a cargo-passenger version by folding the cushion and back of the rear seat forward. Large side doors provide convenient entry and exit for passengers, and the rear door facilitates loading and unloading luggage.

The anatomically shaped front seats with headrests significantly increase comfort. They, like the rear seat, are made of polyurethane foam with knitted material upholstery. The stepless adjustment mechanism allows smooth adjustment of the backrest angle of the front seats. In addition, the front seats can be moved forward and backward both to select their optimal position and to ensure comfortable seating for passengers in the rear seat.

Due to the development of the power scheme of the body frame, high body strength and "soft" absorption of impact energy in the event of an accident have been achieved. Thus, in case of a frontal impact with a stationary obstacle at a speed of about 50 km/h, the windshield remains in the opening, the doors open easily, and the movement of the steering wheel into the passenger compartment does not exceed 90 mm. The power scheme of the body guarantees the preservation of the living space of the passenger compartment in case of impacts from the front, rear, side and when rolling over onto the roof.

High corrosion resistance of the body is achieved primarily by using zinc-coated steel on all corrosion-hazardous parts, floor crossbars, door sill parts, etc. Sealing of welded seams with a special mastic is provided. In addition, increased corrosion resistance is achieved by cataphoretic primer, special treatment of closed cavities and application of an epoxy protective coating during final treatment of the body.

Electrical equipment

The electrical equipment is almost entirely original. Electronics and specialized integrated circuits are widely used in devices and units (voltage regulator, ignition system switch, signal relays). The vehicles are equipped with a low-maintenance or maintenance-free battery, a compact starter with an end manifold, an electronic contactless ignition system, and a system of built-in sensors with instruments that monitor the operation of the vehicle's most important systems.

A new device has been introduced - an economizer, which allows you to select the most economical driving mode. In addition to control devices, the cars are equipped with a special diagnostic system. The connector for turning on the diagnostic equipment of service stations is located under the hood. It is connected to all control points of the electrical equipment system. The diagnostic system allows you to examine the technical condition of the generator, voltage regulator, ignition system, battery, etc.

The electric windshield wiper has three operating modes - two constant (but with different brush speeds) and one intermittent. Some of the cars produced are equipped with headlight washers. To improve the operation of the wipers, there is a glass washer.

Features of the VAZ-2109 car

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Car VAZ-2109 (figure 2) it differs from the VAZ-2108 by its five-door body and minor changes in the engine power supply system.

The engine is equipped with a cold air intake, which takes air directly under the radiator grille. It is made of polypropylene and is fixed above the engine cooling system radiator. The intake is connected to the air filter thermostat by a polypropylene air duct.

The body frame is of a different shape, with two openings for the front and rear doors. The front side doors and their mechanisms have the same design as the doors of the VAZ-2108. The only difference is in the dimensions.

The rear side doors are similar in design to the front ones, but differ slightly in the design of the door locks. The locks are not locked from the outside with a key and are equipped with an additional lock to prevent the lock from being opened from the inside. The lever for this lock is located on the end of the door under the outer lock. If you move the lever down before closing the door, it will be impossible to open the door from the inside. It will only open with the outer door handle.

Features of the VAZ-21081 car

This car is equipped with a VAZ-21081 engine with a reduced working volume (1.1 l) and only a four-speed gearbox. The body and all other units and mechanisms are the same as on the VAZ-2108.

Engine (compared to model 2108) has a different cylinder block, cylinder head, crankshaft and camshaft. Due to the reduced engine displacement, a carburetor with different calibration data is installed, as well as a slightly modified exhaust system.

Features of the design of VAZ-21083 and VAZ-21093 cars

These cars differ from the VAZ-2108 and VAZ-2109 by installing a more powerful 21083 engine with a working volume of 1.5 liters. In addition, they use only a five-speed gearbox. Some cars can be equipped with a digital ignition system.

Engine 21083 has a cylinder block with an increased cylinder diameter (82 mm). The piston diameter and the diameters of the intake valves and channels in the cylinder head are also increased. The carburetor is installed with other calibration data.

Features of the design of VAZ-21099 cars

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The VAZ-21099 differs from all the above-described cars by its four-door sedan body. Its body is three-volume, i.e. it is divided by partitions into three volumes: the engine compartment, the passenger compartment and the luggage compartment with a volume of 0.43 m³. In terms of design and layout, the VAZ-21099 is completely analogous to the VAZ-21093 (except for the rear part of the body). It also has a 21083 engine with a working volume of 1.5 liters and a five-speed gearbox. It is possible to install the instrument panel shown in figure 5.