A car is a technically complex device, consisting of a large number of parts, assemblies and mechanisms. Every self-respecting car owner is obliged to understand them, not even in order to be able to independently eliminate any malfunction that may occur on the road, but simply to understand the principle of operation of their car, and the ability to explain the essence of the problems in a language understandable to a specialist. To do this, you need to know at least the basics, what main parts the car consists of, and how each part is called correctly.
car body
The basis of any car is its body, which is the body of the car, which accommodates the driver, passengers and cargo. It is in the body that all other elements of the car are located. One of its main purposes is to protect the people and goods in it from the effects of the external environment.
The carrier system of the car. It is the skeleton of the car, to which all parts are subsequently attached Usually the body is mounted on the frame, but there are cars with a frameless design, and then the body simultaneously performs the functions of a frame. The structure of the car body is:
- one-volume, when the engine, passenger and cargo compartments are located in one volume (minivans or vans can serve as an example);
- two-volume, which provides engine compartment, and places for passengers and cargo are combined in one volume (station wagons, hatchbacks, crossovers and SUVs);
- three-volume, where separate compartments are provided for each part of the car body - cargo, passenger and motor (pickup trucks, sedans and coupes).
Depending on the nature of the load, the body can be of three types:
- carrier;
- semi-supporting;
- unloaded.
Most modern passenger cars mobile has a supporting structure that takes all the loads acting on the machine. The general arrangement of a car body provides for the following main elements:
- spars, which are load-bearing beams in the form of a rectangular profile pipe, they are front, rear and roof spars;
Body carrier system. This system allows you to reduce the weight of the car, lower the center of gravity, and therefore increase stability when driving. - racks - structural elements that support the roof (front, rear and middle);
- beams and cross members, which are at the roof, spars, under the engine mounts, and each row of seats, there is also a front cross member and a radiator cross member;
- thresholds and floors;
- wheel niches.
Automobile engine, its types
The heart of the car, its main unit is the engine. It is this part of the car that creates the torque that is transmitted to the wheels, causing the car to move in space. Today there are the following main types of motors:
- Internal combustion engine or internal combustion engine, which uses the energy of the fuel burned in its cylinders to obtain mechanical energy;
- electrical motor batteries or hydrogen cells (hydrogen-powered vehicles today are already available from most of the leading automotive companies as prototypes and are even available in small-scale production);
- hybrid engines that combine an electric motor and an internal combustion engine in one unit, the connecting link between which is a generator.
It is a complex of mechanisms that convert the thermal energy of the fuel burning in its cylinders into mechanical energy. According to the type of fuel burned, all internal combustion engines are divided into the following varieties:
- gasoline;
- diesel;
- gas;
- hydrogen, in which liquid hydrogen acts as fuel (installed only on experimental models).
By ICE designs there are:
- piston;
- rotary piston;
- gas turbine.
Transmission
The main purpose of the transmission is to transfer torque from the crankshaft of the engine to the wheels. The elements of which it consists are named as follows:
- The clutch, which is two friction discs pressed against each other, which connect the engine crankshaft to the gearbox shaft. This connection of the shafts of the two mechanisms is made detachable so that, by pressing the disks, it is possible to break the connection between the engine and the gearbox, to change gears and change the speed of rotation of the wheels.
This is a power transmission that interconnects the engine with the driving wheels of the car. - Gearbox (or gearbox). This node is used to change the speed and direction of the car.
- Cardan transmission, which is a shaft with swivel joints at the ends, which serves to transmit torque to the rear drive wheels. It is used only in rear-wheel drive and all-wheel drive vehicles.
- The main gear located on the drive axle of the vehicle. It transmits torque from cardan shaft semiaxes, changing the direction of rotation by 90o.
- The differential is a mechanism that serves to provide different speeds of rotation of the right and left drive wheels when turning the car.
- Drive shafts or axle shafts are elements that transmit rotation to the wheels.
All wheel drive vehicles have transfer case, distributing rotation on both axes.
Chassis
The complex of mechanisms and parts that serve to move the car and extinguish the resulting vibrations and vibrations is called undercarriage. The running gear includes:
- a frame to which all other elements of the chassis are attached (in frameless cars, elements of the car body are used to mount them);
Chassis- a set of devices, the interaction of which is the movement of the car on the road - wheels, consisting of disks and tires;
- front and rear suspension, which serves to dampen vibrations that occur during movement, and can be spring, pneumatic, spring or torsion bar, depending on the damping elements used;
- axle beams used to install axle shafts and differentials, they are available only in cars with dependent suspension.
Most modern cars have independent suspension, and they have no bridge beams.
Steering
For normal movement by car, the driver needs to make turns, U-turns or detours, that is, deviate from a straight line, or simply control his car so that it does not take it to the side. For this purpose, steering is provided in its design. This is one of the simplest mechanisms in a car. What is the name of some of the elements, consider below. Steering comprises:
- steering wheel with a steering column, the so-called ordinary shaft, on which is rigidly mounted wheel;
These devices consist of steering, which is connected to the front wheels by steering and brakes. - the steering mechanism, consisting of a rack and pinion mounted on the steering column shaft, it converts the rotational movement of the steering wheel into the translational movement of the rack in a horizontal plane;
- steering drive, which transmits the impact from the steering gear rack to the wheels to turn them, and includes side rods, a pendulum lever and wheel swivel levers.
AT modern cars an additional element is used - power steering, which allows the driver to apply less effort to ensure the steering wheel is turned. It is of the following types:
- mechanical;
- pneumatic booster;
- hydraulic;
- electric;
- combined electric booster.
Brake system
An important part of the machine that ensures the safety of control is brake system. Its main purpose is to forcibly stop a moving vehicle. It is also used when it is necessary to abruptly reduce the speed of the car.
There are three options for the braking system: working, parking, spare The brake system is of the following types according to the type of drive:
- mechanical;
- hydraulic;
- pneumatic;
- combined.
On modern passenger cars, a hydraulic brake system is installed, which consists of the following elements:
- brake pedals;
- the main hydraulic cylinder of the brake system;
- filling tank of the master cylinder, for filling brake fluid;
- vacuum booster, not available on all models;
- piping systems for front and rear brakes;
- wheel brake cylinders;
- brake pads pressed by the wheel cylinders to the wheel rim during braking vehicle.
Brake pads are disc or drum and have a return spring that pushes them away from the wheel rim when the braking process is completed.
Electrical equipment, which is a set of electrical appliances and apparatus that ensure the normal operation of the engine electrical equipment
One of the most complex passenger car systems with many different elements and wires connecting them, entangling the entire body of the car, is electrical equipment that serves to provide electricity to all electrical devices and the electronic system. Electrical equipment includes the following devices and systems:
- battery;
- generator;
- ignition system;
- light optics and interior lighting system;
- drives of electric motors of fans, windshield wipers, power windows and other devices;
- heating windows and interior;
- all electronics automatic box gears, on-board computer and protective systems (ABS, SRS), engine management and others;
- power steering;
- anti-theft alarm;
- sound signal.
This is an incomplete list of devices included in the electrical equipment of a car and consuming electricity.
The device of the car body and all its constituent parts every driver needs to know in order to keep the car always in good condition.
Each machine consists of at least three constituent parts: engine, transmission and executive mechanism. For example, drilling the machine consists of an electric motor, a V-belt mechanism for transmitting movement and changing the speed of the spindle, an actuator - spindle. The spindle performs directly drilling with a drill fixed in a chuck.
There may be other mechanisms in machines: feed, management, control and regulation, sorting,transportation, packaging.
Motion transmission mechanisms may consist of gears, belt drives with pulleys, gears and racks. In table. 3 shows some gear mechanisms and their conventional graphic designations on kinematic diagrams.
gear mechanisms can have cylindrical and bevel gears. The smaller diameter of the two meshed gears is commonly referred to asgear.
Belt drives transmit rotation from one pulley to another with flat or V-belts.
You got acquainted with the device of such a transmission in the 5th grade when studying a drilling machine.
chain drives transmit rotation from one sprocket to another using a chain, for example, from the pedal sprocket to the sprocket rear wheel bike.
If in belt and chain drives, pulleys and sprockets rotate in the same direction (clockwise or counterclockwise), then in gear drives, two interconnected wheels rotate in different directions.
Gears, pulleys, sprockets are called links mechanisms and machines.
The fixed link of a mechanism or machine is called rack. These are beds, housings, shaft supports.
One of the links that transmits movement to another is called leading. And the link that receives movement from the leading link is called slave. For example, a bicycle sprocket that is pedaled is called a drive sprocket, and a rear wheel sprocket is called a driven sprocket.
If gear, belt and chain transmissions transmit rotational motion from one link to another, then rack and pinion converts the rotary motion of the gear into the translational motion of the rack, or vice versa.
Due to the fact that the diameters of gears, pulleys and sprockets in gears are usually not the same, the driven wheel rotates at a different speed than the drive one. The ratio of the rotational speed of the driving link to the rotational speed of the driven link (or diameter
driven wheel to drive wheel diameter) is referred to as gear ratio i.
i = n 1/ n 2 = D 2 / D 1 ,
where n 1- frequency of rotation of the drive wheel (rpm, i.e. min -1); n 2 - frequency of rotation of the driven wheel (rpm); D1 - diameter of the driving wheel (mm); D 2 - driven wheel diameter (mm).
For example, with a drive pulley diameter of 40 mm and a driven pulley diameter of 80 mm, the gear ratio will be: i = 80: 40 = 2.
Driving and driven wheels, pulleys and sprockets are mounted on the shafts so that they do not turn on them. To do this, the wheel and shaft are connected using a key or splines (Fig. 28). Keyways are cut out in the wheel and shaft, into which they are insertedkey.
If the wheel is fixedly fixed to the shaft by means of a key, then such a keyed connection is called fixed (Fig. 28, a).
If the wheel can move along a shaft with a key or splines and simultaneously transmit rotation, then such a connection is called keyed or splined. sliding(Fig. 28, b, c).
Spline joints are formed by joints of protrusions and depressions on the shaft and gear wheel (Fig. 28, c).
| You can ask your questions on the topic of the presented article by leaving your comment at the bottom of the page. You will be answered by the Deputy General Director of the Mustang Driving School for Academic Affairs Higher school teacher, candidate of technical sciences Kuznetsov Yury Alexandrovich |
Part 1. ENGINE AND ITS MECHANISMS
The engine is a source of mechanical energy.
The vast majority of vehicles use an internal combustion engine.
An internal combustion engine is a device in which the chemical energy of a fuel is converted into useful mechanical work.
Automotive internal combustion engines are classified:
By type of fuel used:
Light liquid (gas, gasoline),
Heavy liquid ( diesel fuel).
Gasoline engines
Petrol carburetor.Fuel-air mixturebeing prepared in carburetor or in the intake manifold using atomizing nozzles (mechanical or electric), then the mixture is fed into the cylinder, compressed, and then ignited with a spark that slips between the electrodes candles .
Petrol injectionMixing occurs by injecting gasoline into the intake manifold or directly into the cylinder using spray nozzles. nozzles ( injector ov). There are systems of single-point and distributed injection of various mechanical and electronic systems. In mechanical injection systems, fuel is dosed by a plunger-lever mechanism with the possibility of electronic adjustment of the mixture composition. In electronic systems, mixture formation is carried out under the control electronic block control (ECU) injection that controls the electric gasoline valves.
gas engines
The engine burns hydrocarbons in the gaseous state as fuel. Most often gas engines I work on propane, but there are others that run on associated (petroleum), liquefied, blast furnace, generator and other types of gaseous fuels.
The fundamental difference between gas engines and gasoline and diesel engines is a higher compression ratio. The use of gas makes it possible to avoid excessive wear of parts, since the processes of combustion of the air-fuel mixture occur more correctly due to the initial (gaseous) state of the fuel. Also, gas engines are more economical, since gas is cheaper than oil and easier to extract.
The undoubted advantages of gas engines include safety and smokelessness of the exhaust.
By themselves, gas engines are rarely mass-produced, most often they appear after the conversion of traditional internal combustion engines, by equipping them with special gas equipment.
Diesel engines
Special diesel fuel is injected at a certain point (before reaching top dead center) into the cylinder at high pressure through an injector. The combustible mixture is formed directly in the cylinder as fuel is injected. The movement of the piston into the cylinder causes heating and subsequent ignition of the air-fuel mixture. Diesel engines are low speed and are characterized by high torque on the engine shaft. An additional advantage of the diesel engine is that, unlike positive ignition engines, it does not need electricity to operate (in automotive diesel engines electrical system used only for launching), and, as a result, is less afraid of water.
According to the method of ignition:
From a spark (gasoline),
From compression (diesel).
According to the number and arrangement of cylinders:
inline,
Opposite,
V - figurative,
VR - figurative,
W - figurative.
inline engine
This engine has been known since the very beginning of automotive engine building. Cylinders are arranged in one row perpendicularly crankshaft.
Dignity:simplicity of design
Flaw:with a large number of cylinders, a very long unit is obtained, which cannot be positioned transversely relative to the longitudinal axis of the vehicle.
Horizontally opposed engines have a lower overall height than in-line or V-engines, which lowers the center of gravity of the entire vehicle. Light weight, compact design and symmetrical layout reduces the vehicle's yaw moment.
V-engine
To reduce the length of the engines, in this engine the cylinders are arranged at an angle of 60 to 120 degrees, with the longitudinal axis of the cylinders passing through the longitudinal axis of the crankshaft.
Dignity:relatively short engine
Flaws:the engine is relatively wide, has two separate heads of the block, increased manufacturing cost, too large a displacement.
VR engines
Looking for compromise solution performance of engines for passenger cars of the middle class came to the creation of VR engines. Six cylinders at 150 degrees form a relatively narrow and generally short engine. In addition, such an engine has only one block head.
W-motors
In the W-family engines, two rows of cylinders in VR-version are connected in one engine.
The cylinders of each row are placed at an angle of 150 to one another, and the rows of cylinders themselves are located at an angle of 720.
A standard car engine consists of two mechanisms and five systems.
Engine mechanisms
Crank mechanism,
Gas distribution mechanism.
Engine systems
System of release of the fulfilled gases.
crank mechanism
The crank mechanism is designed to convert the reciprocating motion of the piston in the cylinder into the rotational motion of the engine crankshaft.
The crank mechanism consists of:
Cylinder block with crankcase,
heads cylinder block,
engine oil pan,
Pistons with rings and fingers,
Shatunov,
crankshaft,
Flywheel.
Cylinder block
It is a one-piece cast part that combines the engine cylinders. On the cylinder block there are bearing surfaces for installing the crankshaft, the cylinder head is usually attached to the upper part of the block, the lower part is part of the crankcase. Thus, the cylinder block is the basis of the engine, on which the rest of the parts are hung.
Cast as a rule - from cast iron, less often - aluminum.
Blocks made from these materials are by no means equivalent in their properties.
So, the cast-iron block is the most rigid, which means that, other things being equal, it withstands the highest degree of forcing and is the least sensitive to overheating. The heat capacity of cast iron is about half that of aluminum, which means that an engine with a cast iron block warms up to operating temperature faster. However, cast iron is very heavy (2.7 times heavier than aluminum), prone to corrosion, and its thermal conductivity is about 4 times lower than that of aluminum, so the engine with a cast iron crankcase has a more stressful cooling system.
Aluminum cylinder blocks are lighter and cooler better, but in this case there is a problem with the material from which the cylinder walls are made directly. If the pistons of an engine with such a block are made of cast iron or steel, then they will wear out the aluminum cylinder walls very quickly. If the pistons are made of soft aluminum, then they will simply “grab” with the walls, and the engine will instantly jam.
Cylinders in an engine block can either be part of the cylinder block casting or be separate replacement bushings that can be "wet" or "dry". In addition to the forming part of the engine, the cylinder block has additional functions, such as the basis of the lubrication system - through the holes in the cylinder block, oil under pressure is supplied to the lubrication points, and in liquid-cooled engines, the base of the cooling system - through similar holes, the liquid circulates through the cylinder block.
The walls of the inner cavity of the cylinder also serve as guides for the piston when it moves between extreme positions. Therefore, the length of the generatrices of the cylinder is predetermined by the magnitude of the piston stroke.
The cylinder operates under conditions of variable pressures in the over-piston cavity. Its inner walls are in contact with the flame and hot gases heated to a temperature of 1500-2500°C. Besides average speed sliding of the piston set along the walls of the cylinder in automotive engines reaches 12-15 m / s with insufficient lubrication. Therefore, the material used for the manufacture of cylinders must have high mechanical strength, and the design of the walls itself must have increased rigidity. The cylinder walls must resist abrasion well with limited lubrication and have an overall high resistance to other possible types wear
In accordance with these requirements, pearlitic gray cast iron with small additions of alloying elements (nickel, chromium, etc.) is used as the main material for cylinders. High-alloy cast iron, steel, magnesium and aluminum alloys are also used.
cylinder head
It is the second most important and largest component of the engine. Combustion chambers, valves and cylinder plugs are located in the head, it also rotates on bearings camshaft with fists. Just like in the cylinder block, there are water and oil channels and cavities in its head. The head is attached to the cylinder block and, when the engine is running, forms a single whole with the block.
Engine oil pan
Closes the crankcase from below (cast as a single unit with the cylinder block) and is used as a reservoir for oil and protects engine parts from contamination. There is a drain plug at the bottom of the pan engine oil. The pan is bolted to the crankcase. A gasket is installed between them to prevent oil leakage.
Piston
A piston is a cylindrical part that performs a reciprocating motion inside the cylinder and serves to convert a change in the pressure of a gas, vapor or liquid into mechanical work, or vice versa - a reciprocating motion into a change in pressure.
The piston is divided into three parts that perform different functions:
Bottom,
sealing part,
Guide part (skirt).
The shape of the bottom depends on the function performed by the piston. For example, in internal combustion engines, the shape depends on the location of the spark plugs, injectors, valves, engine design, and other factors. With a concave shape of the bottom, the most rational combustion chamber is formed, but soot is deposited more intensively in it. With a convex bottom, the strength of the piston increases, but the shape of the combustion chamber worsens.
The bottom and the sealing part form the piston head. Compression and oil scraper rings are located in the sealing part of the piston.
The distance from the bottom of the piston to the groove of the first compression ring is called the firing zone of the piston. Depending on the material from which the piston is made, the fire belt has a minimum allowable height, a decrease in which can lead to burnout of the piston along the outer wall, as well as destruction of the seat of the upper compression ring.
The sealing functions performed by the piston group are of great importance for normal operation piston engines. The technical condition of the engine is judged by the sealing ability of the piston group. For example, in automobile engines it is not allowed that oil consumption due to its waste due to excessive penetration (suction) into the combustion chamber exceeds 3% of fuel consumption.
The piston skirt (tronk) is its guiding part when moving in the cylinder and has two tides (lugs) for installing the piston pin. To reduce the temperature stresses of the piston on both sides, where the bosses are located, from the surface of the skirt, metal is removed to a depth of 0.5-1.5 mm. These recesses, which improve the lubrication of the piston in the cylinder and prevent the formation of scuffing from temperature deformations, are called "refrigerators". An oil scraper ring can also be located at the bottom of the skirt.
For the manufacture of pistons, gray cast irons and aluminum alloys are used.
Cast iron
Advantages:Cast iron pistons are strong and wear resistant.
Due to their low coefficient of linear expansion, they can operate with relatively small gaps, providing good cylinder sealing.
Flaws:Cast iron has a fairly large specific gravity. In this regard, the scope of cast iron pistons is limited to relatively low-speed engines, in which the inertia forces of the reciprocating masses do not exceed one sixth of the gas pressure force on the piston bottom.
Cast iron has a low thermal conductivity, so the heating of the bottom of cast iron pistons reaches 350–400 °C. Such heating is undesirable, especially in carbureted engines, as it is the cause of incandescent ignition.
Aluminum
The vast majority of modern car engines have aluminum pistons.
Advantages:
Low weight (at least 30% less compared to cast iron);
High thermal conductivity (3-4 times higher than the thermal conductivity of cast iron), which ensures that the piston crown does not heat up more than 250 ° C, which contributes to better filling of the cylinders and allows you to increase the compression ratio in gasoline engines;
Good anti-friction properties.
connecting rod
A connecting rod is a part that connects piston (throughpiston pin) and crankpincrankshaft. Serves to transmit reciprocating movements from the piston to the crankshaft. For less wear of the connecting rod journals of the crankshaft, aspecial liners that have an anti-friction coating.
Crankshaft
The crankshaft is a complex-shaped part with necks for fastening connecting rods , from which it perceives efforts and converts them into torque .
Crankshafts are made of carbon, chromium-manganese, chromium-nickel-molybdenum, and other steels, as well as special high-strength cast irons.
The main elements of the crankshaft
root neck- shaft support, lying in the main bearing located in crankcase engine.
Connecting rod journal- a support with which the shaft is connected to connecting rods (there are oil channels for lubrication of connecting rod bearings).
Cheeks- connect the main and connecting rod necks.
Front shaft output (toe) - part of the shaft on which it is attached gear or pulley power take-off for drivegas distribution mechanism (GRM)and various auxiliary units, systems and assemblies.
Rear output shaft (shank) - part of the shaft connected to flywheel or massive gear selection of the main part of the power.
Counterweights- provide unloading of the main bearings from the centrifugal inertia forces of the first order of the unbalanced masses of the crank and the lower part of the connecting rod.
Flywheel
Massive disc with a toothed rim. The ring gear is necessary to start the engine (the starter gear engages with the flywheel gear and spins the engine shaft). The flywheel also serves to reduce uneven rotation of the crankshaft.
Gas distribution mechanism
Designed for the timely intake of a combustible mixture into the cylinders and the release of exhaust gases.
The main parts of the gas distribution mechanism are:
Camshaft,
Inlet and outlet valves.
Camshaft
According to the location of the camshaft, engines are distinguished:
With camshaft located in cylinder block (Cam-in-Block);
With a camshaft located in the cylinder head (Cam-in-Head).
In modern automotive engines, it is usually located at the top of the block head cylinders and connected to pulley or toothed sprocket crankshaft belt or timing chain, respectively, and rotates at half the frequency than the latter (on 4-stroke engines).
An integral part of the camshaft are its cams , the number of which corresponds to the number of intake and exhaust valves engine. Thus, each valve corresponds to an individual cam, which opens the valve by running on the valve lifter lever. When the cam "runs away" from the lever, the valve closes under the action of a powerful return spring.
Engines with an in-line configuration of cylinders and one pair of valves per cylinder usually have one camshaft (in the case of four valves per cylinder, two), while V-shaped and opposed engines have either one in the collapse of the block, or two, one for each half-block ( in each block head). Engines with 3 valves per cylinder (most commonly two intake and one exhaust) typically have one camshaft per head, while those with 4 valves per cylinder (two intake and 2 exhaust) have 2 camshafts per head.
Modern engines sometimes they have valve timing adjustment systems, that is, mechanisms that allow the camshaft to be rotated relative to the drive sprocket, thereby changing the moment of opening and closing (phase) of the valves, which makes it possible to more efficiently fill the cylinders with the working mixture at different speeds.
valve
The valve consists of a flat head and a stem connected by a smooth transition. To better fill the cylinders with a combustible mixture, the diameter of the head of the intake valves is made much larger than the diameter of the exhaust. Since the valves operate at high temperatures, they are made of high quality steels. Inlet valves are made of chromium steel, exhaust valves are made of heat-resistant steel, since the latter come into contact with combustible exhaust gases and heat up to 600 - 800 0 C. Heat heating of the valves necessitates the installation of special inserts made of heat-resistant cast iron in the cylinder head, which are called seats.
The principle of the engine
Basic concepts
Top dead center - the highest position of the piston in the cylinder.
bottom dead center - the lowest position of the piston in the cylinder.
piston stroke- the distance that the piston travels from one dead center to another.
The combustion chamber- the space between the cylinder head and the piston when it is at top dead center.
Cylinder displacement - the space released by the piston when it moves from top dead center to bottom dead center.
Engine displacement - the sum of the working volumes of all engine cylinders. It is expressed in liters, which is why it is often called the displacement of the engine.
Full cylinder volume - the sum of the volume of the combustion chamber and the working volume of the cylinder.
Compression ratio- shows how many times the total volume of the cylinder is greater than the volume of the combustion chamber.
Compressionpressure in the cylinder at the end of the compression stroke.
Tact- the process (part of the working cycle) that occurs in the cylinder in one stroke of the piston.
Engine duty cycle
1st stroke - inlet. When the piston moves down in the cylinder, a vacuum is formed, under the action of which, through the open intake valve, the cylinder enters combustible mixture(mixture of fuel with air).
2nd measure - compression . The piston moves up under the action of the crankshaft and the connecting rod. Both valves are closed and the combustible mixture is compressed.
3rd cycle - working stroke . At the end of the compression stroke, the combustible mixture ignites (from compression in a diesel engine, from a spark plug in petrol engine). Under the pressure of expanding gases, the piston moves down and drives the crankshaft through the connecting rod.
4th measure - release . The piston moves up and the exhaust gases exit through the opened exhaust valve.
Nowadays, life without a car is unimaginable. This is no longer a luxury, but a simple means of transportation, a reliable friend and assistant who will come to the rescue in a difficult situation. However, with the increase in the number of cars in the population, the number of owners who do not understand its device at all increases. However, it is simply necessary to know the structure of a car for beginners, at least for self-development and general erudition, as well as in order not to get into a mess in a car service in an attempt to explain on the fingers what exactly happened to the car in the event of a breakdown.
Despite the greatest diversity, all machines are essentially the same, and therefore general device car can be considered on a generalized example.
What is a car made of?
Any passenger car includes the following components:
- engine
- transmission
- chassis
- electrical equipment
- body
This is the order in which the car is always considered in any auto mechanics textbook, and for good reason: these nodes are in order of importance.
Engine
The engine of a car is its main part. It drives the vehicle itself and simultaneously supplies energy to the service units. The engine is almost always located in the front, but sometimes its rear location is also found (mainly on sports cars). The most common today is the internal combustion engine (ICE) - it burns fuel, converting thermal energy into kinetic (rotation). Engines are petrol, diesel and gas. In these three cases, the difference lies only in the type of fuel used and the features of the engine's duty cycle. By the way, can diesel engine and put on the Niva. There are also automotive electric motors, but they are a minority, despite the undoubted advantages.
The engine torque must be used as efficiently as possible, because when driving slowly, the engine cannot work slowly, and when driving fast, it cannot work quickly. The transmission converts the speed of the engine, slowing it down or speeding it up. The transmission is a clutch, a gearbox and a final drive with a differential.
The clutch serves to mechanically disengage the wheels and the engine when the machine is not required to move. The gearbox allows you to drive at different speeds at the same engine speed. It can be mechanical (manual) and automatic. In the first case, the gears are switched on by the driver himself using a special lever, in the second, the gears are selected automatically depending on the driving speed and the load on the car. The second option allows you to make control easier, but the device itself of such a unit is much more complicated. The main gear sends torque directly to the wheels, and the differential allows them to rotate at different speeds (this is mainly needed in turns).
Also, the composition of the transmission may vary depending on the type of drive. The engine can turn only the front, only the rear, or all wheels together. In the first case, the rotation from the main gear goes through the axle shafts immediately to the front wheels. In the second case (if the engine is in front), a special cardan shaft is added to the transmission, leading to the rear wheels through the entire machine. On all-wheel drive vehicles (jeeps and crossovers), after the gearbox, another transfer case is installed, which distributes the rotation between the front and rear wheels.
Chassis
It consists of components directly related to the movement - suspension, wheels, brakes. The suspension of the car serves to smooth out the reactive moments that occur when driving through bumps, in other words, it makes the ride softer and smoother. In addition, the suspension eliminates and reduces body roll and lean when cornering, keeping the car in a predetermined horizontal position. The suspension consists of shock absorbers and springs, as well as various levers and hinges. The characteristics of the suspension determine the smoothness of the ride and the general behavior on the road. Brakes are used to slow down the movement and stop the car in different situations. They are located directly next to the wheels.
electrical equipment
Electrical equipment is a very important equipment system. In our time, when there are more and more electronic assistants, the role of electrical equipment is becoming ever higher. In the most general version, it consists of a battery, a generator, ignition systems, lighting, and control devices. Since various systems consume a lot of electricity, the engine rotates the generator during its operation, which provides all consumers, and also charges the battery, which serves to start the motor.
Body
The body is, roughly speaking, a metal box in which all of the above units are installed. The body, together with attachments (doors, hood, fenders), form the appearance of the car and protect the driver, passengers and all components from atmospheric influences. Almost all modern passenger cars are equipped with load-bearing bodies, i.e. all components are installed on it, unlike trucks, for example, where a frame is used - a special element to which the engine, cab, body, suspension, etc. are attached. Usage load-bearing body allows significantly, by 10-20% to reduce the total weight.
Of course, numerous pictures and books can give a more complete picture of the structure of the machine, however, in most cases, general theoretical knowledge is quite enough to understand, for example, that problems with electrical equipment can be the reason that the engine “troits”, and knocks and rumbles when driving over bumps indicate a malfunction in the suspension. Therefore, the device of a car for "dummies", despite the complexity of the systems and the abundance of car services, can always help in a difficult situation.
There are drivers who drive their cars, but do not know at all what the car consists of. It may not be necessary to know all the subtleties of the complex operation of the mechanism, but the main points should still be known to everyone. After all, the life of both the driver himself and other people can depend on this. At its core, the simplified consist of three parts:
- engine;
- chassis;
- body.
In the article, we will take a closer look at what parts the car consists of and how they affect the operation of the vehicle as a whole.
What does a car consist of: diagram
The device of the car can be represented as follows.
In the vast majority of cases, internal combustion engines are installed on the machines. Since they are not ideal, developments have been and are being made to invent new motors. So, recently, cars with electric motors, which can be charged with a normal socket. The Tesla electric car is very famous. However, it is certainly too early to talk about the wide distribution of such machines.
The chassis, in turn, consists of:
- transmission or power transmission;
- running;
- vehicle control mechanism.
The body is designed to accommodate passengers in the car and comfortable movement. The main body types today are:
- sedan;
- hatchback;
- cabriolet;
- station wagon;
- limousine;
- and others.
ICE: types
Any person understands that malfunctions in the operation of the motor can become dangerous to the health and life of people. Therefore, it is vital to know what is
Translated from Latin, motor means "setting in motion." In a car, it is understood as a device that is designed to convert one type of energy into mechanical energy.
Gas engines operate on liquefied, generator compressed gas. Such fuel is stored in cylinders, from where it enters the reducer through the evaporator and loses pressure. The further process is similar to the injection motor. Sometimes, however, the evaporator is not used.
Motor operation
To better understand the principle of operation, you need to analyze in detail what it consists of
The body is a cylinder block. Inside it are channels that cool and lubricate the motor.
The piston is nothing more than a hollow metal cup, at the top of which are the grooves of the rings.
The piston rings located at the bottom are oil scraper, and at the top - compression. The latter provide good compression and compression air-fuel mixture. They are used both to achieve the tightness of the combustion chamber, and as seals to prevent oil from entering there.
The crank mechanism is responsible for the reciprocating energy of the pistons on the crankshaft.
So, understanding what a car consists of, in particular, its engine, let's look at the principle of operation. The fuel first enters the combustion chamber, mixes with air there, the spark plug (in gasoline and gas versions) produces a spark, igniting the mixture, or the mixture ignites itself (in diesel version) under the influence of pressure and temperature. The formed gases cause the piston to move down, transferring the movement to the crankshaft, due to which it begins to rotate the transmission, where the movement is transmitted to the front wheels, rear axle or both at once, depending on the drive. A little later, we will touch on what the wheel of a car consists of. But first things first.
Transmission
Above, we found out what the car consists of, and we know that the chassis includes a transmission, chassis and control mechanism.
The following elements are distinguished in the transmission:
- clutch;
- main and cardan gears;
- differential;
- drive shafts.
Operation of transmission parts
The clutch serves to disconnect (KP) from the engine, then smoothly connect them when shifting gears and when starting off.
The gearbox changes the torque transmitted from the crankshaft to the driveshaft. The gearbox block disconnects the connection of the motor with the driveline as much as necessary for the vehicle to move in reverse.
The main function of the cardan transmission is the transmission of torque from the gearbox to the main gear at different angles.
The main function of the final drive is to transmit torque at a ninety degree angle from the propeller shaft through the differential to the drive shafts of the main wheels.
The differential rotates the drive wheels at different speeds when cornering and on uneven ground.
Chassis
The chassis of the car consists of a frame, front and rear axles, connected to the frame through the suspension. In most modern cars the frame is the elements that make up the suspension of the car, the following:
- springs;
- cylinder springs;
- shock absorbers;
- pneumatic cylinders.
Control mechanisms
These devices consist of which is connected to the front wheels by steering and brakes. Most modern cars use on-board computers, themselves controlling the management in some cases, and even making the necessary changes.
Here we note such an important part as what the car wheel consists of. Without him, the car would simply not take place. This truly one of the greatest inventions here consists of two components: a tire made of rubber, which can be chambered and tubeless, and a metal disc.
Body
In most cars today, the body is a carrier, which consists of individual elements connected by welding. Bodies today are very diverse. The main one is the closed type, which has one, two, three, and sometimes even four rows of seats. Part or even the entire roof can be removed. It is either hard or soft.
If the roof is removed in the middle, then this is a targa body.
A fully removable soft top is obtained in a convertible.
If it is not soft, but hard, then this is a hardtop convertible.
On the station wagon, similar to the sedan, there is some extension above the luggage compartment, which is a distinguishing feature.
And the van will turn out already from the station wagon if the rear doors and windows are sealed.
With a cargo platform behind the driver's cab, the body is called a pickup truck.
A coupe is a two-door closed body.
The same, but with a soft top, was called a roadster.
Cargo-passenger body with back door the back is called a combo.
A limousine is a closed type with a rigid partition behind the front seats.
From the article, we found out what the car consists of. Important good work all components, and it is better understood and felt when there is appropriate knowledge.