The principle of operation and the device of the car engine. Car engine maintenance

For about a hundred years, everywhere in the world, the main power unit on cars and motorcycles, tractors and combines, other equipment is the engine. internal combustion. Arriving at the beginning of the twentieth century to replace engines external combustion(steam), even in the twenty-first century it remains the most cost-effective type of motor. In this article, we will consider in detail the device, the principle of operation of various types of internal combustion engines and its main auxiliary systems.

Definition and general features of the internal combustion engine

The main feature of any internal combustion engine is that the fuel ignites directly inside its working chamber, and not in additional external carriers. During operation, chemical and thermal energy from fuel combustion is converted into mechanical work. Principle ICE operation based on the physical effect of thermal expansion of gases, which is formed during the combustion process fuel-air mixture under pressure inside the engine cylinders.

Classification of internal combustion engines

In the process of evolution of internal combustion engines, the following types of these motors have proven their effectiveness:

• Piston internal combustion engines. In them, the working chamber is located inside the cylinders, and the thermal energy is converted into mechanical work by means of a crank mechanism that transfers the energy of motion to the crankshaft. piston motors divided in turn into
• carburetor, in which the air-fuel mixture is formed in the carburetor, injected into the cylinder and ignited there by a spark from a spark plug;

• injection, in which the mixture is fed directly into the intake manifold, through special nozzles, under control electronic block control, and is also ignited by means of a candle;
• diesel, in which ignition is air- fuel mixture occurs without a candle, by compressing air, which is heated by pressure from a temperature exceeding the combustion temperature, and fuel is injected into the cylinders through nozzles.
• Rotary piston internal combustion engines. In motors of this type, thermal energy is converted into mechanical work by rotating the working gases of the rotor special form and profile. The rotor moves along a “planetary trajectory” inside the working chamber, which has the shape of a “eight”, and performs the functions of both a piston and a timing (gas distribution mechanism), and crankshaft.
• gas turbine internal combustion engines. In these motors, the transformation of thermal energy into mechanical work is carried out by rotating the rotor with special wedge-shaped blades, which drives the turbine shaft.

The most reliable, unpretentious, economical in terms of fuel consumption and the need for regular maintenance are piston engines.

Equipment with other types of internal combustion engines can be included in the Red Book. Nowadays only Mazda makes cars with rotary piston engines. An experimental series of cars with a gas turbine engine was produced by Chrysler, but it was in the 60s, and none of the automakers returned to this issue. IN THE USSR gas turbine engines tanks "T-80" and landing ships "Zubr" were equipped, but in the future it was decided to abandon this type of motor. In this regard, let us dwell in detail on the "world-dominated" reciprocating internal combustion engines.

The engine housing combines into a single organism:

• cylinder block, inside the combustion chambers of which the fuel-air mixture ignites, and the gases from this combustion drive the pistons;
• crank mechanism , which transfers the energy of motion to the crankshaft;
• gas distribution mechanism, which is designed to ensure the timely opening / closing of valves for intake / exhaust combustible mixture and exhaust gases;
• supply system ("injection") and ignition ("ignition") of the fuel-air mixture;
• combustion products removal system (exhaust gases).

Cross section of a four-stroke internal combustion engine

When the engine is started, an air-fuel mixture is injected into its cylinders through the intake valves and ignites there from a spark plug spark. During combustion and thermal expansion of gases from excess pressure, the piston sets in motion, transferring mechanical work to the rotation of the crankshaft.

The operation of a piston internal combustion engine is carried out cyclically. These cycles are repeated at a frequency of several hundred times per minute. This ensures continuous translational rotation of the crankshaft exiting the engine.

Let's define terminology. A stroke is a work process that occurs in an engine in one stroke of the piston, more precisely, in one of its movements in one direction, up or down. A cycle is a set of cycles that repeat in a certain sequence. By the number of cycles within one worker ICE cycle They are subdivided into two-stroke (the cycle is carried out in one revolution of the crankshaft and two strokes of the piston) and four-stroke (for two revolutions of the crankshaft and four pistons). At the same time, both in those and in other engines, the working process goes according to the following plan: intake; compression; combustion; expansion and release.

The principles of operation of the internal combustion engine

- The principle of operation of a two-stroke engine

When the engine starts, the piston, entrained by the rotation of the crankshaft, begins to move. As soon as it reaches its bottom dead center (BDC) and proceeds to move up, a fuel-air mixture is supplied to the combustion chamber of the cylinder.

In its upward movement, the piston compresses it. At the moment the piston reaches its top dead center (TDC), a spark from a candle electronic ignition ignites the air-fuel mixture. Instantly expanding, the vapors of burning fuel rapidly push the piston back to the bottom dead center.

At this time, the exhaust valve opens, through which hot exhaust gases are removed from the combustion chamber. Having passed BDC again, the piston resumes its movement to TDC. During this time, the crankshaft makes one revolution.

With a new movement of the piston, the inlet channel of the fuel-air mixture opens again, which replaces the entire volume of exhaust gases, and the whole process is repeated anew. Due to the fact that the work of the piston in such motors is limited to two strokes, it makes a much smaller number of movements per unit of time than in a four-stroke engine. Friction losses are minimized. However, a lot of heat energy is released, and two-stroke engines heat up faster and more strongly.

In two-stroke engines, the piston replaces the gas distribution valve mechanism, during its movement at certain moments, opening and closing the intake and exhaust working openings in the cylinder. Worse, compared with a four-stroke engine, gas exchange is the main drawback of a two-stroke ICE system. At the moment of removal of exhaust gases, a certain percentage of not only the working substance, but also power is lost.

The areas of practical application of two-stroke internal combustion engines are mopeds and scooters; outboard motors, lawn mowers, chainsaws, etc. low power technology.

These shortcomings are deprived of four-stroke internal combustion engines, which, in various options, and are installed on almost all modern cars, tractors and other equipment. In them, the intake / exhaust of a combustible mixture / exhaust gases are carried out as separate workflows, and not combined with compression and expansion, as in two-stroke ones. With the help of the gas distribution mechanism, the mechanical synchronization of the operation of the intake and exhaust valves with the crankshaft speed is ensured. In a four-stroke engine, the injection of the fuel-air mixture occurs only after the complete removal of exhaust gases and the closing of the exhaust valves.

The working process of an internal combustion engine

Each stroke of work is one stroke of the piston in the range from top to bottom dead center. In this case, the engine goes through the following phases of operation:

• Stroke one, inlet. The piston moves from top dead center to bottom dead center. At this time, a vacuum occurs inside the cylinder, the intake valve opens and the fuel-air mixture enters. At the end of the intake, the pressure in the cylinder cavity is in the range from 0.07 to 0.095 MPa; temperature - from 80 to 120 degrees Celsius.
• Bar two, compression. When the piston moves from bottom to top dead center and the intake and exhaust valves are closed, the combustible mixture is compressed in the cylinder cavity. This process is accompanied by an increase in pressure up to 1.2-1.7 MPa, and temperature - up to 300-400 degrees Celsius.
• Bar three, expansion. The fuel-air mixture ignites. This is accompanied by the release of a significant amount of thermal energy. The temperature in the cavity of the cylinder rises sharply to 2.5 thousand degrees Celsius. Under pressure, the piston moves quickly to its bottom dead center. The pressure indicator in this case is from 4 to 6 MPa.
• Bar four, issue. During the reverse movement of the piston to the top dead center, the exhaust valve opens, through which the exhaust gases are pushed out of the cylinder into the exhaust pipe, and then into the environment. The pressure indicators in the final stage of the cycle are 0.1-0.12 MPa; temperature - 600-900 degrees Celsius.

Auxiliary systems of the internal combustion engine

The ignition system is part of the electrical equipment of the machine and is designed to provide a spark, igniting the fuel-air mixture in the working chamber of the cylinder. The components of the ignition system are:

• Power supply. During engine start, this is the battery, and during its operation, the generator.
• Switch, or ignition switch. It was previously mechanical, and in last years increasingly electric contact device to supply electricity.
• Energy storage. A coil, or autotransformer, is a unit designed to store and convert enough energy to cause the desired discharge between the spark plug electrodes.
• Ignition distributor (distributor). A device designed to distribute a high voltage pulse along the wires leading to the candles of each of the cylinders.

ICE ignition system

- intake system

The ICE intake system is designed For uninterrupted filing into the motor atmospheric air, for mixing it with fuel and preparing a combustible mixture. It should be noted that in the carburetor engines of the past, the intake system consists of an air duct and air filter. And that's it. The composition of the intake system of modern cars, tractors and other equipment includes:

• air intake. It is a branch pipe of a form convenient for each particular engine. Through him atmospheric air is sucked into the engine, through the difference in pressure in the atmosphere and in the engine, where a vacuum occurs when the pistons move.
• Air filter. This is a consumable product designed to clean the air entering the motor from dust and solid particles, their retention on the filter.
• throttle valve. Air valve designed to regulate the supply of the desired amount of air. Mechanically, it is activated by pressing the gas pedal, and in modern technology- with the help of electronics.
• Intake manifold. Distributes the air flow through the engine cylinders. To give air flow the desired distribution, special intake flaps and a vacuum booster are used.

Fuel system, or system ICE power supply, "responsible" for uninterrupted fuel supply to form a fuel-air mixture. Part fuel system includes:

• Fuel tank- a container for storing gasoline or diesel fuel, with a device for taking fuel (pump).
• Fuel lines- a set of tubes and hoses through which its "food" enters the engine.
• Mixing device, i.e. carburetor or injector- a special mechanism for the preparation of the fuel-air mixture and its injection into the internal combustion engine.
• Electronic control unit(ECU) mixture formation and injection - in injection engines, this device is "responsible" for synchronous and efficient work on the formation and supply of a combustible mixture to the engine.
• Fuel pump - electrical device for pumping gasoline or diesel fuel into the fuel line.
• The fuel filter is a consumable for additional purification of fuel during its transportation from the tank to the engine.

ICE fuel system diagram

- Lubrication system

Purpose of the system engine lubricants -friction reduction and its destructive effect on parts; abduction parts of the excess heat; removal products soot and wear; protection metal against corrosion. The engine lubrication system includes:

• Oil pan- storage tank engine oil. The oil level in the sump is controlled not only by a special dipstick, but also by a sensor.
• Oil pump- pumps oil from the sump and delivers it to the necessary engine parts through special drilled channels - "lines". Under the influence of gravity, the oil flows down from the lubricated parts, back into the oil pan, accumulates there, and the lubrication cycle is repeated again.
• Oil filter traps and removes solid particles from engine oil formed from soot and wear products of parts. The filter element is always replaced with a new one with every engine oil change.
• Oil radiator Designed to cool engine oil using liquid from the engine cooling system.

Exhaust system ICE serves for removing spent gases And noise reduction motor work. In modern technology, the exhaust system consists of the following parts (in order of exhaust gases leaving the engine):

• An exhaust manifold. This is a pipe system made of heat-resistant cast iron, which receives hot exhaust gases, dampens their primary oscillatory process and sends them further to the exhaust pipe.
• Downpipe- a curved gas outlet made of fire-resistant metal, popularly referred to as "pants".
• Resonator, or, in popular language, the “bank” of the muffler is a container in which exhaust gases are separated and their speed is reduced.
• Catalyst- a device designed for purification of exhaust gases and their neutralization.
• Muffler- a container with a complex of special partitions designed to repeatedly change the direction of gas flow and, accordingly, their noise level.

exhaust internal combustion engine system

- Cooling system

If on mopeds, scooters and cheap motorcycles is still applied air system engine cooling - with a counter flow of air, then for more powerful equipment it, of course, is not enough. This is where a liquid cooling system comes into play. For absorbing excess heat at the motor and reduction of thermal loads on its details.

• Radiator The cooling system is used to release excess heat to the environment. It consists of a large number curved aluminum tubes, with fins for additional heat dissipation.
• Fan designed to enhance the cooling effect on the radiator from the oncoming air flow.
• Water pump(pump) - "drives" the coolant in the "small" and "large" circles, ensuring its circulation through the engine and radiator.
• Thermostat- a special valve that ensures the optimum temperature of the coolant by starting it in a "small circle", bypassing the radiator (when the engine is cold) and in a "large circle", through the radiator - when the engine is warm.

The coordinated work of these auxiliary systems ensures maximum efficiency from the internal combustion engine and its reliability.

In conclusion, it should be noted that in the foreseeable future, worthy competitors to the internal combustion engine are not expected to appear. There is every reason to assert that in its modern, improved form, it will remain the dominant type of motor in all sectors of the world economy for several decades to come.

A car engine can look like a big tangled mess. metal parts, tubes and wires for the uninitiated. At the same time, the engine is the "heart" of almost any car - 95% of all cars run on an internal combustion engine.

In this article, we will discuss the operation of an internal combustion engine: its general principle, we will study the specific elements and phases of the engine, find out exactly how potential fuel is converted into rotational force, and try to answer the following questions: how does an internal combustion engine work, what are the engines and their types, and what do certain engine parameters and characteristics mean? And, as always, all this is as simple and accessible as two times two.

The main purpose of a car's gasoline engine is to convert gasoline into motion so that your car can move. Currently, the easiest way to create motion from gasoline is to simply burn it inside the engine. Thus, an automobile "engine" is an internal combustion engine - i.e. the combustion of gasoline takes place inside it.

Exist different kinds internal combustion engines. Diesel engines are one of the forms, and gas turbines are a completely different one. Each of them has its own advantages and disadvantages.

Well, as you will notice, since there is an internal combustion engine, there must be an external combustion engine. The steam engine in old-fashioned trains and steamboats is just the same best example external combustion engine. The fuel (coal, wood, oil, whatever) in a steam engine burns outside the engine to create steam, and the steam creates motion inside the engine. Of course, an internal combustion engine is much more efficient (at least consumes much less fuel per kilometer of a vehicle) than an external combustion engine, and an internal combustion engine is much smaller than an equivalent external combustion engine. This explains why we do not see a single car that looks like a steam locomotive.

Now let's take a closer look at how an internal combustion engine works.

Let's look at the principle behind any reciprocating motion of an internal combustion engine: if you place not a large number of high-energy fuel (such as gasoline) into a small enclosed space and ignite it (this fuel), an incredible amount of energy will be released in the form of an expanding gas. You can use this energy, for example, to move a potato. In this case, the energy is converted into the movement of this potato. For example, if you pour some gasoline into a pipe with one end tightly closed and the other open, and then stick a potato and set fire to gasoline, then its explosion will provoke the propulsion of this potato by squeezing it out with exploding gasoline, thus, the potato will fly high into the sky if you point the tube up. This we briefly described the principle of operation of an old cannon. But you can also use this energy of gasoline for more interesting purposes. For example, if you can cycle gasoline explosions hundreds of times per minute, and if you can put that energy to good use, then you already have a car engine core!

Almost all cars nowadays use what is called four stroke combustion cycle to convert gasoline into motion. The four-stroke cycle is also known as the Otto cycle, after Nicholas Otto, who invented it in 1867. So, here they are, these 4 strokes of the engine:

1. Fuel intake stroke
2. Fuel compression stroke
3. Fuel combustion stroke
4. Exhaust stroke

Everything seems to be clear from this, isn't it? You can see in the figure below that an element called a piston replaces potatoes in the "potato gun" we described earlier. The piston is connected to the crankshaft with a connecting rod. Just do not be afraid of new terms - there are actually not so many of them in principle of engine operation!

In the figure, the letters indicate the following elements of the engine:

A - Camshaft
B - Valve cover
C - Exhaust valve
D - Exhaust port
E - cylinder head
F - Coolant chamber
G - Engine block
H - Oil sump
I - Engine sump
J - spark plug
K - intake valve
L - Inlet
M - Piston
N - Connecting rod
O - Connecting rod bearing
P - Crankshaft

Here's what happens when an engine goes through its full four-stroke cycle:

1. The initial position of the piston is at the very top, at this moment the intake valve opens, and the piston moves down, thus sucking the prepared mixture of gasoline and air into the cylinder. This is the intake stroke. Just a tiny drop of gasoline needs to mix with the air to make it all work.
2. When the piston reaches its lowest point, the intake valve closes, and the piston begins to move back up (gasoline is "trapped"), compressing this mixture of fuel and air. Compression will subsequently make the explosion more powerful.
3. When the piston reaches the top of its stroke, the spark plug releases a spark generated by more than tens of thousands of volts to ignite the gasoline. Detonation occurs, and the gasoline in the cylinder explodes, pushing the piston down with incredible force.
4. After the piston reaches the bottom of its stroke again, it is the turn of the exhaust valve to open. Then the piston moves up (this happens already by inertia) and the spent mixture of gasoline and air leaves the cylinder through the exhaust port to start its journey to the exhaust pipe and further into the upper atmosphere.

Now that the valve is back at the top, the engine is ready for the next cycle, so it sucks in the next mixture of air and gasoline to spin the crankshaft even more, which actually transmits its torsion further through the transmission to the wheels. Now look below how the engine works in all its four cycles.

You can see the operation of an internal combustion engine more clearly in the two animations below:

How the engine works - animation

Note that the motion that is created by the operation of an internal combustion engine is rotation, while the motion created by the "potato gun" is linear (straight). In the engine, the linear motion of the pistons is converted into rotational motion of the crankshaft. We need rotational motion because we are planning to turn our car wheels.

Now let's look at all the parts that work together as a team to make this happen, starting with the cylinders!

The core of an engine is a cylinder with a piston that moves up and down inside the cylinder. The engine described above has one cylinder. It would seem, what else is needed for a car ?! But no, for a comfortable ride, a car needs at least 3 more such cylinders with pistons and all the attributes necessary for this couple (valves, connecting rods, and so on), but one cylinder is suitable only for most lawn mowers. Look - below in the animation you will see the work of a 4-cylinder engine:

Engine types

Cars most often have four, six, eight and even ten, twelve and sixteen cylinders (the last three options are installed mainly on sports cars and fireballs). IN multi-cylinder engine all cylinders are usually arranged in one of three ways:

• inline
• V-shaped
• Opposite

Here they are - all three types of cylinder arrangement in the engine:

In-line arrangement of 4 cylinders

Opposite arrangement of 4 cylinders

V-arrangement of 6 cylinders

Various configurations have different benefits and disadvantages in terms of vibration, production cost, and shape characteristics. These advantages and disadvantages make them more suitable for the use of certain specific Vehicle. Thus, 4-cylinder engines rarely make sense in V-shaped, so they are usually in-line; and 8-cylinder engines are made more often with V-arrangement cylinders.

Now let's visually see how the fuel injection system, oil and other components in the engine work:

Let's look at some of the key engine parts in more detail:

And now attention! Based on everything we read, let's look at the full cycle of the engine with all its elements:

Full engine cycle

Why is the engine not running?

Let's say you go out to the car in the morning and start it up, but it won't start. What could be wrong? Now that you know how an engine works, you can understand the basic things that can prevent an engine from starting. Three fundamental things can happen:

• Bad fuel mixture
• No compression
• No spark

Yes, there are a thousand other minor things that can create problems, but this " big three" is most often the result or cause of one of them. Based on a simple understanding of the operation of the engine, we can make a short list of how these problems affect the engine.

A bad fuel mixture can be due to one of the following reasons:

• You simply ran out of gas in the tank, and the engine is trying to start from the air.
• The air intake may be clogged, so the engine is getting fuel but not enough air to detonate.
• The fuel system may be supplying too much or too little fuel to the mixture, meaning that combustion is not occurring properly.
• There may be impurities in the fuel (and this is especially true for the Russian quality of gasoline), which prevent the fuel from fully burning.

Lack of Compression - If the charge of air and fuel cannot be compressed properly, the combustion process will not work properly. Lack of compression can occur for the following reasons:

• Piston rings worn (allowing air and fuel to flow past the piston when compressed)
• Inlet or outlet valves not sealing properly, re-opening a leak during compression
• There is a hole in the cylinder.

The lack of spark can be for a number of reasons:

• If the spark plugs or the wire leading to them are worn out, the spark will be weak.
• If the wire is damaged or simply missing, or if the system that sends the spark through the wire is not working properly.
• If the spark occurs either too early or too late in the cycle, the fuel will not be ignited at right time and that can cause all sorts of problems.

And here are a number of other reasons why the engine may not work, and here we will touch on some details outside the engine:

• If the battery is dead, you will not be able to crank the engine over to start it.
• If the bearings that allow the crankshaft to turn freely are worn out, the crankshaft will not be able to turn, so the engine will not be able to run.
• If the valves don't open and close at the right time, or don't work at all, air can't get in and exhaust can't get out, so the engine won't be able to run again.
• If someone with hooligan motives put a potato in the exhaust pipe, the exhaust gases will not be able to exit the cylinder, and the engine will not work again.
• If there is not enough oil in the engine, the piston will not be able to move up and down freely in the cylinder, making it difficult or impossible for the engine to operate normally.

In a properly running engine, all of these factors are within tolerance. As you can see, the engine has a number of systems that help it do its job of converting fuel into propulsion flawlessly. We will look at the various subsystems used in engines in the following sections.

Most engine subsystems can be implemented using various technologies, and best technology can significantly improve engine performance. That is why the development of the automotive industry continues at the highest pace, because the competition among automakers is great enough to invest big money in every additional squeezed out horsepower from the engine with the same volume. Let's take a look at the various subsystems used in modern engines, starting with how valves work in an engine.

How do valves work?

The valve system consists of the actual valves and the mechanism that opens and closes them. The system of opening and closing them is called camshaft . The camshaft has special parts on their axis, which move the valves up and down, as shown in the figure below.

Most modern engines have what is called overhead cams. This means that the shaft is located above the valves, as you can see in the picture. Old engines use camshaft located in the crankcase near the crankshaft. The camshaft, while rotating, moves the cam with the protrusion down so that it pushes the valve down, creating a gap for the passage of fuel or exhaust gases. The timing belt or chain drive is driven by the crankshaft and transmits torque from it to the camshaft so that the valves are in sync with the pistons. The camshaft always turns one to two times slower than the crankshaft. Many high performance engines have four valves per cylinder (two for intake and two for exhaust).

How does the ignition system work?

The ignition system generates a high voltage charge and transmits it to the spark plugs using the ignition wires. The charge first passes to the ignition coil (a kind of distributor that distributes the spark supply to the cylinders at a certain time), which you can easily find under the hood of most cars. The ignition coil has one wire going in the center and four, six, eight wires or more depending on the number of cylinders that come out of it. These ignition wires send charge to each spark plug. The engine receives such a spark over time in such a way that only one cylinder receives a spark from the distributor at one time. This approach ensures maximum engine smoothness.

How does cooling work?

The cooling system in most vehicles consists of a radiator and a water pump. Water circulates through passages (channels) around the cylinders, and then passes through the radiator to cool it as much as possible. However, there are such car models (primarily Volkswagen Beetle(Beetle)), as well as most motorcycles and lawn mowers that have an air-cooled engine. You've probably seen these air-cooled engines that have fins on the side, a ribbed surface that adorns the outside of each cylinder to help dissipate heat.

Air cooling makes the engine lighter, but hotter, and generally reduces engine life and overall performance. So now you know how and why your engine stays warm.

How does the launch system work?

Improving the performance of your engine is a big deal, but more importantly is what happens when you turn the key to start it! The starting system consists of a starter with an electric motor. When you turn the ignition key, the starter turns the engine a few revolutions to start the combustion process, and it can only be stopped by turning the key in the opposite direction, when the spark ceases to flow into the cylinders, and the engine thus stalls.

The starter has powerful electric motor, which rotates a cold internal combustion engine. The starter is always quite powerful and, therefore, the engine “eating” battery resources, because it must overcome:

• All internal friction caused by piston rings and exacerbated by cold cold oil.
• The compression pressure of any cylinder(s) that occurs during the compression stroke.
• The resistance exerted by the opening and closing of the valves by the camshaft.
• All other processes directly related to the engine, including water pump resistance, oil pump, generator, etc.

We see that the starter needs a lot of energy. The car most often uses a 12-volt electrical system, and hundreds of amps of electricity must flow to the starter.

How does the injection and lubrication system work?

When it comes daily maintenance car, your first concern is probably to check the amount of gasoline in your car. And how does gasoline get from the fuel tank to the cylinders? The fuel system of the engine sucks gasoline out of the tank with the help of fuel pump which is in the tank and mixes it with air so that the proper mixture of air and fuel can flow into the cylinders. Fuel is delivered in one of three common ways: carburetor, fuel injection, and direct fuel injection.

Carburettors are very outdated today, and they are not placed in new car models. In an injection engine, the right amount of fuel is injected individually into each cylinder, either directly into the intake valve (fuel injection) or directly into the cylinder (direct fuel injection).

Oil also plays important role. A perfectly and properly lubricated system ensures that every moving part in the engine receives oil so that it can move easily. The two main parts that need oil are the piston (or more precisely, its rings) and any bearings that allow elements such as the crankshaft and other shafts to rotate freely. In most vehicles, oil is sucked from the oil pan by the oil pump, passed through an oil filter to remove dirt particles, and then sprayed under high pressure onto the bearings and cylinder walls. The oil then drains into a sump where it is collected again and the cycle repeats.

Exhaust system

Now that we know about a number of things that we put (poured) in our car, let's look at other things that come out of it. The exhaust system includes an exhaust pipe and a muffler. Without a muffler, you would hear the sound of thousands of small explosions from your exhaust pipe. The silencer dampens the sound. The exhaust system also includes catalytic converter, which uses a catalyst and oxygen to burn off any unused fuel and some other chemicals in the exhaust. Thus, your car meets certain European standards for air pollution.

What else is there besides all of the above in the car? electrical system consists of a battery and a generator

How does an engine work? Video

Before considering the issue how a car engine works, it is necessary at least in general terms understand his device. In any car, an internal combustion engine is installed, the operation of which is based on the conversion of thermal energy into mechanical energy. Let's look deeper into this mechanism.

How a car engine works - we study the device diagram

The classic engine device includes a cylinder and a crankcase, closed in the lower part by a pan. Inside the cylinder is located with various rings, which moves in a certain sequence. It has the shape of a glass, in its upper part there is a bottom. To finally understand how a car engine works, you need to know that the piston with the help of piston pin and the connecting rod is connected to the crankshaft.

For smooth and soft rotation, indigenous and connecting rod bearings playing the role of bearings. The composition of the crankshaft includes the cheeks, as well as the main and connecting rod journals. All these parts, assembled together, are called a crank mechanism, which converts the reciprocating movement of the piston into circular rotation.

The upper part of the cylinder is closed by the head, where the intake and exhaust valves. They open and close in accordance with the movement of the piston and the movement of the crankshaft. To accurately understand how a car engine works, the videos in our library should be studied in as much detail as the article. In the meantime, we will try to express its effect in words.

How a car engine works - briefly about complex processes

So, the piston displacement limit has two extreme positions- top and bottom dead center. In the first case, the piston is at the maximum distance from the crankshaft, and the second option is the smallest distance between the piston and the crankshaft. In order to ensure that the piston passes through dead centers without stopping, a flywheel made in the form of a disk is used.

An important parameter for internal combustion engines is the compression ratio, which directly affects its power and efficiency.

To correctly understand the principle of operation of a car engine, you need to know that it is based on the use of the work of gases expanded during the heating process, as a result of which the piston moves between the top and bottom dead centers. When the piston is in the upper position, combustion of fuel enters the cylinder and is mixed with air. As a result, the temperature of gases and their pressure increases significantly.

The gases do useful work, due to which the piston moves down. Further, through the crank mechanism, the action is transmitted to the transmission, and then to car wheel. Waste products are removed from the cylinder through the exhaust system, and a new portion of fuel is supplied in their place. The entire process, from fuel injection to exhaust gas, is called the engine's duty cycle.

The principle of operation of a car engine - differences in models

There are several main types of internal combustion engines. The simplest is an in-line engine. Arranged in one row, they make up a certain working volume as a whole. But gradually, some manufacturers moved away from this manufacturing technology to a more compact version.

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The principle of operation of a four-stroke internal combustion engine
This principle and cyclicality is called the "OTTO Cycle"

look...
Inline internal combustion engine

V-shaped internal combustion engine

Boxer internal combustion engine

Rotorno piston engine internal combustion

Scheme of the ignition system of an internal combustion engine


A. Wire to spark plug
B. Distributor cover
C. Slider
D. Ignition coil high voltage wire
E. Distributor body
F. Distributor cam
G. Ignition pulse sensor
H. Ignition control unit
I. Ignition coil
J. Candles

WANKEL ROTARY PISTON ENGINE

Advantages and disadvantages of modern RPD compared to traditional internal combustion engines

Advantages:
30 - 40% fewer parts
Significantly less specific gravity. Compact design. Complete
mass balance. Lack of gas distribution
mechanism. The engine is high-torque and very elastic, which allows less frequent
change gears. Easily upgradeable for
work on hydrogen.

Flaws:
In a stretched RPD combustion chamber, it is difficult to create turbulent
high intensity movement for fast and complete combustion
combustible mixture, which worsens the efficiency of the engine and
makes it harder to deal with harmful emissions. Unable to create
diesel RPD. Greater oil consumption (to lubricate the combustion chamber)

1. The rotor rotates on a longitudinal shaft, the shaft has an eccentric,
in fact, the rotor is spinning on it, and the gear is present for
transmission desired phase rotor when rotating on an eccentric.
2. The rotation of the rotor on the shaft is lubricated, there is an oil pump in the RPD
and oil pan. The angular surface of the rotor in the combustion chamber
is not lubricated, it uses a gasket material made of
teflon, which has the function of sealing and sliding, but on
side surfaces of the rotor are supplied with oil, which is inevitable
enters the combustion chamber, therefore, the environmental friendliness of the RPD cannot
to talk...

ICE with piston "Swing"

The piston of the new motor, cut in half, clearly shows
one of its main advantages. The blue inserts represent
coolant that is supplied to the piston through its
reference axis

Technical terms

DOHC - Double Over-Head Camshaft (Two Overhead Camshafts)
SOHC - Single Over-Head Camshaft
OHC - Over-Head Camshaft
Twin Cam - Twin Cam - NOT TWO CAMS!
(If the engine uses two valves with a single and
simultaneous function, at the air inlet or outlet
exhaust gases, while both single-function valves,
simultaneously driven by their own cam
camshaft. Two valves - "twin", plus two single-phase
camshaft cams and are the "TWIN CAM" system.
This system is used only in engines with a "DOHC" system)

HETC - High Efficiency Twin Cam - (Double cam with high efficiency,
Twin Cam system with variable valve timing)
Supercharger - Supercharger (Roots compressor, mechanical supercharger, which
It is driven by the crankshaft through a drive belt.
Power increase system, without engine speed increase)
EFI - Electronic Fuel Injection - ( electronic injection fuel)
GDI - Gasolin Direct Injection - (gasoline direct injection)
MPI - Multi Point Injection - (ported fuel injection)
Intercooler - Intermediate air cooling.
4WD - 4 Wheel Drive - (4 wheel drive)
4WS - 4 Wheels Swivel - (4 swivel wheels) All 4 wheels are steered
when turning, with the rear wheels at speeds up to 35 km / h. turn around
in the opposite direction to the front, and more speed in the same
AWD- All wheel Drive - (All wheel drive)
FWD - Four Wheel Drive - (Four wheel drive)

GT (Gran Turismo)
Literally translated as "big trip"
GT car class are high speed cars like
rule with a 2- or 4-seater coupe body designed for
public roads. The abbreviation GT is also
designation racing class in car competitions.
There is also an incorrect broad interpretation of the term,
according to which all sports cars are included in the GT category
shape.

GTi - Gran Turismo Iniezione (vehicle equipped with fuel injection)
GTR-Gran Turismo Racer
GTO - Gran Turismo Omologato (Vehicle eligible for GT racing)
GTS-Gran Turismo Spider
GTB - Gran Turismo Berlinetta (coupé with long bonnet and gently sloping roof)
GTV - Gran Turismo Veloce (Designation for uprated GT cars)
GTT-Gran Turismo Turbo
GTE - Einspritzung German for fuel injection (this is the German analogue of the GTi index)
GTA - Gran Turismo Alleggerita (Light GT car)
GTAm modified lightened car
GTC - Gran Turismo Compressore/Compact/Cabriolet/Coupe
GTD-Gran Turismo Diesel
HGT-High Gran Turismo

BEAMS (Breakthrough Engine with Advanced Mechanism System)
The latest engine with an improved system of mechanisms
BEAMS is a whole family (or generation) of engines
(absolutely all types) with installed mechanical
gas distribution mechanisms with the possibility of changing
phases of any design: VVT, VTEC, MIVEC, Vanos or any
others. BEAMS is a common automotive term related not
only to Toyota, but also to Subaru, BMW, Mercedes, Audi, Honda and others.
The next generation of engines was named Dual BEAMS and
applied to internal combustion engines with installed gas distribution
mechanisms VVT-i, iVTEC, Double Vanos, Bi-Vanos and others with
additional electronic control other than mechanical
drive.

CVVT (Continuous variable valve timing)
Variable valve timing system
Alfa Romeo - Double continuous variable valve timing. CVVT is used on intake and exhaust
BMW - VANOS/Double VANOS. First used in 1993 for the BMW 3 and 5 series
PSA Peugeot Citro?n - Continuous variable valve timing (CVVT)
Chrysler - dual Variable Valve Timing (dual VVT)
Daihatsu - Dynamic variable valve timing (DVVT)
General Motors - Continuous variable valve timing (CVVT)
Honda - i-VTEC = VTEC. First used in 1990 on Civic and CRX vehicles
Hyundai - Continuous variable valve timing (CVVT) - debuted in 2.0 L Beta I4 engine
in 2005 in the Elantra and Kia Spectra", was also applied
in a new engine (Alpha II DOHC) in 2006 for Accent \ Verna, Tiburon and Kia cee'd cars
MG Rover - Variable Valve Control (VVC)
Mitsubishi - Mitsubishi Innovative Valve timing Electronic Control (MIVEC). First used in 1992 in the 4G92 engine
Nissan - Continuous Variable Valve Timing Control System (CVTCS)
Toyota - Variable Valve Timing with intelligence (VVT-i), Variable Valve Timing with Lift and Intelligence (VVTL-i)
Volvo - Continuous variable valve timing (CVVT)

An internal combustion engine with a rotating cylinder
intake and exhaust valve function.



four-stroke engine, which does not have the usual valves and
their entire drive system. Instead, the British forced to work
the gas distributor itself is the working cylinder of the engine, which in
motors RCV rotates around its own axis. The piston at the same time
makes exactly the same movements as before. And here are the walls
cylinder rotate around the piston (the cylinder is fixed inside
motor on two bearings). A branch pipe is arranged from the edge of the cylinder,
which alternately opens to the inlet or outlet
window. A sliding seal is also provided here, working
similar to piston rings - it allows the cylinder
expand when heated, without losing tightness. lead
cylinder in rotation, only three gears: one on the cylinder, one
on the crankshaft and one - intermediate. Naturally, the speed
rotation of the cylinder - half the revolutions of the crankshaft.

The key part of the cylinder rotation drive is the intermediate
combination gear.

A two-stroke engine is a piston internal combustion engine in which the working process in each of the cylinders takes place in one revolution of the crankshaft, that is, in two piston strokes. The compression and stroke strokes in a two-stroke engine occur in the same way as in a four-stroke one, but the processes of cleaning and filling the cylinder are combined and are carried out not within separate strokes, but in a short time when the piston is near the bottom dead center, with the help of an auxiliary unit - a purge pump.
Due to the fact that in a two-stroke engine, with an equal number of cylinders and the number of revolutions of the crankshaft, the working strokes occur twice as often, the liter power of two-stroke engines is higher than that of four-stroke engines - theoretically twice, in practice 1.5-1.7 times, since part of the useful stroke of the piston is occupied by gas exchange processes, and the gas exchange itself is less perfect than that of four-stroke engines.
Unlike four-stroke engines, where the displacement of exhaust gases and the suction of a fresh mixture is carried out by the piston itself, in two-stroke engines, gas exchange is carried out by supplying to the cylinder working mixture or air (in diesel engines) under pressure created by a purge pump, and the gas exchange process itself is called purge. During the scavenging process, fresh air (mixture) forces combustion products out of the cylinder into the exhaust organs, taking their place.
According to the method of organizing the movement of purge air flows (mixtures), two-stroke engines are distinguished with contour and direct-flow purge.

The invention of the internal combustion engine allowed mankind to step forward significantly in development. Now the engines that use to perform useful work The energy released during the combustion of fuel is used in many areas of human activity. But these engines are most widely used in transport.

All power plants consist of mechanisms, components and systems that, interacting with each other, ensure the conversion of the energy released during the combustion of flammable products into the rotational movement of the crankshaft. It is this movement that is his useful work.

To make it clearer, you should understand the principle of operation of the internal combustion power plant.

Principle of operation

When a combustible mixture consisting of flammable products and air is burned, more energy is released. Moreover, at the moment of ignition of the mixture, it significantly increases in volume, the pressure in the epicenter of ignition increases, in fact, a small explosion occurs with the release of energy. This process is taken as a basis.

If combustion takes place in a closed space, the pressure arising during combustion will press on the walls of this space. If one of the walls is made movable, then the pressure, trying to increase the volume closed space, will move this wall. If some rod is attached to this wall, then it will already perform mechanical work - moving away, it will push this rod. By connecting the rod to the crank, when moving, it will cause the crank to rotate about its axis.

This is the working principle power unit with internal combustion - there is a closed space (cylinder liner) with one movable wall (piston). The wall is connected by a rod (rod) to a crank (crankshaft). Then the reverse action is performed - the crank, making a full turn around the axis, pushes the wall with the rod and so returns back.

But this is only the principle of work with an explanation on simple components. In fact, the process looks a little more complicated, because you must first ensure that the mixture enters the cylinder, compress it for better ignition, and also remove the combustion products. These actions are called cycles.

Total bars 4:

• inlet (the mixture enters the cylinder);
• compression (the mixture is compressed by reducing the volume inside the sleeve by the piston);
• working stroke (after ignition, the mixture pushes the piston down due to its expansion);
• release (removal of combustion products from the sleeve to supply the next portion of the mixture);

Piston engine strokes

It follows from this that only the working stroke has a useful action, the other three are preparatory. Each stroke is accompanied by a certain movement of the piston. During intake and stroke, it moves down, and during compression and exhaust, it moves up. And since the piston is connected to the crankshaft, each stroke corresponds to a certain angle of rotation of the shaft around the axis.

The implementation of cycles in the engine is done in two ways. The first - with the combination of cycles. In such a motor, all cycles are performed in one complete crankshaft rotation. That is, half a turn of the knees. shaft, in which the movement of the piston up or down is accompanied by two cycles. These engines are called 2-stroke.

The second way is separate beats. One piston movement is accompanied by only one stroke. As a result, in order for a full cycle of work to occur, 2 turns of the knees are required. shaft around the axis. Such engines were designated 4-stroke.

Cylinder block

Now the internal combustion engine device itself. The basis of any installation is the cylinder block. All components are located in it and on it.

The design features of the block depend on certain conditions - the number of cylinders, their location, and the method of cooling. The number of cylinders that are combined in one block can vary from 1 to 16. Moreover, blocks with an odd number of cylinders are rare; of the engines currently produced, only one- and three-cylinder installations can be found. Most of the units come with a pair of cylinders - 2, 4, 6, 8 and less often 12 and 16.

Four-cylinder block

Power plants with 1 to 4 cylinders usually have an in-line arrangement of cylinders. If the number of cylinders is greater, they are arranged in two rows, with a certain angle of position of one row relative to the other, the so-called power plants with a V-shaped position of the cylinders. This arrangement made it possible to reduce the dimensions of the block, but at the same time their manufacture is more difficult than in-line arrangement.

Eight-cylinder block

There is another type of blocks in which the cylinders are arranged in two rows and with an angle between them of 180 degrees. These engines are called . They are found mainly on motorcycles, although there are also cars with this type of power unit.

But the condition for the number of cylinders and their location is optional. There are 2-cylinder and 4-cylinder engines with a V-shaped or opposed position of the cylinders, as well as 6-cylinder engines with an in-line arrangement.

Two types of cooling are used, which are used in power plants - air and liquid. Depends on design feature block. The air-cooled unit is smaller and structurally simpler, since the cylinders are not included in its design.

The block with liquid cooling is more complicated, its design includes cylinders, and a cooling jacket is located on top of the block with cylinders. A fluid circulates inside it, removing heat from the cylinders. In this case, the block together with the cooling jacket represents one whole.

From above, the block is covered with a special plate - the cylinder head (cylinder head). It is one of the components that provide a closed space in which the combustion process takes place. Its design can be simple, not including additional mechanisms, or complex.

crank mechanism

Included in the design of the motor, it provides the conversion of the reciprocating movement of the piston in the sleeve into the rotational movement of the crankshaft. The main element of this mechanism is the crankshaft. It has a movable connection with the cylinder block. Such a connection ensures the rotation of this shaft around the axis.

A flywheel is attached to one end of the shaft. The task of the flywheel is to transmit torque from the shaft further. Since a 4-stroke engine has only one half-turn for every two revolutions of the crankshaft, useful action- working stroke, the rest require the reverse action, which is performed by the flywheel. Having a significant mass and rotating, due to its kinetic energy, it provides turning of the knees. shaft during the preparatory cycles.

The flywheel circumference has a ring gear, with the help of which the power plant is started.

On the other side of the shaft is the drive gear of the oil pump and gas distribution mechanism, as well as a flange for mounting the pulley.

This mechanism also includes connecting rods, which provide power transfer from the piston to the crankshaft and vice versa. The connecting rods are also movably attached to the shaft.

Surfaces of the cylinder block, knees. shaft and connecting rods at the joints do not directly contact each other, between them there are plain bearings - liners.

Cylinder-piston group

Consists of this group from cylinder liners, pistons, piston rings and pins. It is in this group that the combustion process and the transfer of the released energy for transformation take place. Combustion takes place inside the sleeve, which is closed on one side by the head of the block, and on the other by the piston. The piston itself can move inside the sleeve.

To ensure maximum tightness inside the liner, piston rings are used to prevent leakage of the mixture and combustion products between the walls of the liner and the piston.

The piston is movably connected to the connecting rod by means of a pin.

Gas distribution mechanism

The task of this mechanism is the timely supply of a combustible mixture or its components to the cylinder, as well as the removal of combustion products.

Two-stroke engines do not have a mechanism as such. In it, the supply of the mixture and the removal of combustion products are carried out by technological windows that are made in the walls of the sleeve. There are three such windows - inlet, bypass and outlet.

The piston, moving, opens and closes one or another window, and this is how the sleeve is filled with fuel and exhaust gases are removed. The use of such gas distribution does not require additional components, therefore the cylinder head of such an engine is simple and its task is only to ensure the tightness of the cylinder.

The 4-stroke engine has a gas distribution mechanism. Fuel from such an engine is supplied through special holes in the head. These openings are closed with valves. If it is necessary to supply fuel or remove gases from the cylinder, the corresponding valve is opened. The opening of the valves provides a camshaft, which with its cams in right moment presses on the required valve and it opens the hole. The camshaft is driven by the crankshaft.

Timing belt and chain drive

The layout of the gas distribution mechanism may vary. Engines are produced with a lower camshaft (it is located in the cylinder block) and an overhead valve (in the cylinder head). The transmission of force from the shaft to the valves is carried out by means of rods and rocker arms.

More common are motors in which both the shaft and valves are on top. With this arrangement, the shaft is also located in the cylinder head and it acts directly on the valves, without intermediate elements.

Supply system

This system provides preparation of fuel for its further supply to the cylinders. The design of this system depends on the fuel used by the engine. The main now is the fuel isolated from oil, and different fractions - gasoline and diesel fuel.

Gasoline engines have two types of fuel system - carburetor and injection. In the first system, mixture formation is carried out in a carburetor. It doses and supplies fuel to the air flow passing through it, then this mixture is already fed into the cylinders. Such a system consists of a fuel tank, fuel lines, a vacuum fuel pump and a carburetor.

Carburetor system

The same is done in injection cars, but they have a more accurate dosage. Also, the fuel in the injectors is added to the air stream already in the inlet pipe through the nozzle. This injector sprays fuel, which provides better mixture formation. The injection system consists of a tank, a pump located in it, filters, fuel lines, and fuel rail with injectors mounted on the intake manifold.

In diesel engines, the components of the fuel mixture are supplied separately. The gas distribution mechanism supplies only air to the cylinders through the valves. Fuel is supplied to the cylinders separately, by nozzles and under high pressure. Consists of this system from the tank, filters, high pressure fuel pump (TNVD) and injectors.

Recently, injection systems have appeared that work on the principle of a diesel fuel system - an injector with direct injection.

The exhaust gas system ensures the removal of combustion products from the cylinders, partial neutralization harmful substances, and sound reduction when the exhaust gas is removed. It consists of an exhaust manifold, a resonator, a catalyst (not always) and a silencer.

Lubrication system

The lubrication system reduces friction between the interacting surfaces of the engine by creating a special film that prevents direct contact of the surfaces. Additionally, it removes heat, protects engine elements from corrosion.

The lubrication system consists of an oil pump, an oil tank - a pan, an oil intake, oil filter, channels through which oil moves to rubbing surfaces.

Cooling system

Maintaining optimal operating temperature during engine operation is provided by the cooling system. Two types of systems are used - air and liquid.

The air system produces cooling by blowing air through the cylinders. For better cooling, cooling fins are made on the cylinders.

In a liquid system, cooling is provided by a liquid that circulates in the cooling jacket in direct contact with the outer wall of the sleeves. Such a system consists of a cooling jacket, a water pump, a thermostat, pipes and a radiator.

Ignition system

The ignition system is only used on gasoline engines. On diesel engines, the mixture is ignited by compression, so he does not need such a system.

In gasoline cars, ignition is carried out by a spark that jumps at a certain moment between the electrodes of a glow plug installed in the block head so that its skirt is in the combustion chamber of the cylinder.

The ignition system consists of an ignition coil, distributor (distributor), wiring and spark plugs.

electrical equipment

This equipment provides electricity to the on-board network of the car, including the ignition system. This equipment is also used to start the engine. It consists of a battery, a generator, a starter, wiring, various sensors that monitor the operation and condition of the engine.

This is the whole device of the internal combustion engine. Although it is constantly being improved, its principle of operation does not change, only individual nodes and mechanisms are improved.

Modern developments

The main task that automakers are struggling with is to reduce fuel consumption and emissions of harmful substances into the atmosphere. Therefore, they are constantly improving the nutrition system, the result is the recent appearance injection systems with direct injection.

Looking for alternative fuels latest development in this direction so far is the use of alcohols as fuel, as well as vegetable oils.

Scientists are also trying to establish the production of engines with a completely different principle of operation. Such, for example, is the Wankel engine, but so far there has been no particular success.

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