How does an internal combustion engine work. How the engine works

The vast majority of cars use oil derivatives as fuel for engines. When these substances are burned, gases are released. In a confined space, they create pressure. A complex mechanism perceives these loads and transforms them first into translational motion, and then into rotational. This is the principle of operation of the engine. internal combustion. Further, the rotation is already transmitted to the drive wheels.

piston engine

What is the advantage of such a mechanism? What gave a new principle of operation of the internal combustion engine? Currently, they are equipped not only with cars, but also with agricultural and loading vehicles, train locomotives, motorcycles, mopeds, and scooters. Engines of this type are installed on military equipment: tanks, armored personnel carriers, helicopters, boats. You can also think of chainsaws, mowers, motor pumps, generator substations and other mobile equipment that uses diesel fuel, gasoline or a gas mixture for operation.

Before the invention of the principle of internal combustion, fuel, more often solid (coal, firewood), was burned in a separate chamber. For this, a boiler was used that heated the water. Steam was used as the primary source of driving force. Such mechanisms were massive and overall. They were equipped with locomotives of steam locomotives and ships. The invention of the internal combustion engine made it possible to significantly reduce the dimensions of mechanisms.

System

When the engine is running, a number of cyclical processes constantly occur. They must be stable and take place within a strictly defined period of time. This condition provides smooth operation all systems.

Diesel engines do not pre-treat the fuel. The fuel supply system delivers it from the tank, and it is fed under high pressure into the cylinders. Gasoline is pre-mixed with air along the way.

The principle of operation of an internal combustion engine is such that the ignition system ignites this mixture, and crank mechanism receives, transforms and transfers the energy of gases to the transmission. The gas distribution system releases combustion products from the cylinders and takes them outside vehicle. At the same time, the sound of the exhaust is reduced.

The lubrication system provides the possibility of rotation of moving parts. However, the rubbing surfaces heat up. The cooling system ensures that the temperature does not go beyond allowed values. Although all processes take place in automatic mode they still need to be watched. This is provided by the control system. It transmits data to the control panel in the driver's cab.

Enough complex mechanism must have a body. The main components and assemblies are mounted in it. Optional equipment for systems that ensure its normal operation, is placed nearby and mounted on removable mounts.

The crank mechanism is located in the cylinder block. The main load from the burnt fuel gases is transferred to the piston. It is connected by a connecting rod to crankshaft, which converts forward movement into rotation.

Also in the block is a cylinder. A piston moves along its inner plane. Grooves are cut into it, in which o-rings are placed. This is necessary to minimize the gap between the planes and create compression.

The cylinder head is attached to the top of the body. A gas distribution mechanism is mounted in it. It consists of a shaft with eccentrics, rocker arms and valves. Their alternate opening and closing ensure the inlet of fuel into the cylinder and then the release of spent combustion products.

The pallet of the cylinder block is mounted to the bottom of the case. Oil flows there after it lubricates the rubbing joints of parts of assemblies and mechanisms. Inside the engine there are still channels through which the coolant circulates.

The principle of operation of the internal combustion engine

The essence of the process is the transformation of one type of energy into another. This occurs when fuel is burned in the closed space of an engine cylinder. The gases released during this expand, and excess pressure is created inside the working space. It is received by the piston. He can move up and down. The piston is connected to the crankshaft by means of a connecting rod. In fact, these are the main parts of the crank mechanism - the main unit responsible for converting the chemical energy of the fuel into rotational movement of the shaft.

The principle of operation of the internal combustion engine is based on the alternate cycle change. When the piston moves downward, work is done - the crankshaft rotates at a certain angle. A massive flywheel is fixed at one end. Having received acceleration, it continues to move by inertia, and this still turns the crankshaft. The connecting rod is now pushing the piston up. He takes up the working position and is again ready to take on the energy of the ignited fuel.

Peculiarities

The principle of operation of the internal combustion engine cars most often based on the conversion of the energy of combustible gasoline. Trucks, tractors and special equipment equipped mainly with diesel engines. LPG can also be used as fuel. Diesel engines do not have an ignition system. Fuel ignition comes from generated pressure in the working chamber of the cylinder.

The working cycle can be carried out in one or two revolutions crankshaft. In the first case, there are four cycles: fuel inlet and ignition, power stroke, compression, exhaust gases. Two stroke engine internal combustion, a complete cycle is carried out in one revolution of the crankshaft. At the same time, fuel is admitted and compressed in one cycle, and ignition, power stroke and exhaust gases are released in the second cycle. The role of the gas distribution mechanism in engines of this type is played by a piston. Moving up and down, it alternately opens the fuel inlet and exhaust ports.

Except piston internal combustion engines there are also turbine, jet and combined internal combustion engines. The conversion of fuel energy in them into the forward motion of the vehicle is carried out according to other principles. Engine device and auxiliary systems is also significantly different.

Losses

Despite the fact that the internal combustion engine is reliable and stable, its efficiency is not high enough, as it might seem at first glance. In mathematical dimension Engine efficiency internal combustion averages 30-45%. This suggests that most of the energy of the combustible fuel is wasted.

The efficiency of the best gasoline engines can be only 30%. And only massive economical diesel engines, which have many additional mechanisms and systems, can effectively convert up to 45% of fuel energy in terms of power and useful work.

The design of the internal combustion engine cannot eliminate losses. Part of the fuel does not have time to burn and leaves with the exhaust gases. Another article of losses is the energy consumption to overcome various types of resistance during friction of the mating surfaces of parts of assemblies and mechanisms. And another part of it is spent on actuating the engine systems that ensure its normal and uninterrupted operation.

It would not be an exaggeration to say that most self-propelled devices today are equipped with internal combustion engines of various designs, using various operating principles. In any case, if we talk about road transport. In this article, we will take a closer look at ICE. What it is, how this unit works, what are its pros and cons, you will learn by reading it.

The principle of operation of internal combustion engines

The main principle of operation of an internal combustion engine is based on the fact that fuel (solid, liquid or gaseous) burns in a specially allocated working volume inside the unit itself, converting thermal energy into mechanical energy.

The working mixture entering the cylinders of such an engine is compressed. After its ignition, with the help of special devices, an excess pressure of gases arises, forcing the pistons of the cylinders to return to their original position. This creates a constant working cycle that converts kinetic energy into torque with the help of special mechanisms.

To date internal combustion engine device can be of three main types:

• often called easy;
• four stroke power unit allowing for higher power outputs and efficiency values;
• with enhanced power characteristics.

In addition, there are other modifications of the main circuits that improve certain properties of power plants of this type.

Benefits of internal combustion engines

Unlike power units that provide for the presence of external chambers, the internal combustion engine has significant advantages. The main ones are:

• much more compact dimensions;
• more high performance power;
• optimal efficiency values.

It should be noted, speaking of the internal combustion engine, that this is a device that in the vast majority of cases allows you to use different kinds fuel. It can be gasoline, diesel fuel, natural or kerosene, and even ordinary wood.

Such versatility has given this engine concept its well-deserved popularity, ubiquity and truly world leadership.

Brief historical excursion

It is generally accepted that the internal combustion engine has been counting its history since the creation by the Frenchman de Rivas in 1807 of a piston unit that used hydrogen in a gaseous state of aggregation as fuel. And although since then the ICE device has undergone significant changes and modifications, the main ideas of this invention continue to be used today.

First four stroke engine internal combustion saw the light in 1876 in Germany. In the mid-80s of the XIX century, a carburetor was developed in Russia, which made it possible to dose the supply of gasoline to the engine cylinders.

And at the very end of the century before last, the famous German engineer proposed the idea of ​​\u200b\u200bignition combustible mixture under pressure, which significantly increased the power internal combustion engine characteristics and efficiency indicators of units of this type, which previously left much to be desired. Since then, the development of internal combustion engines has been mainly along the path of improvement, modernization and the introduction of various improvements.

The main types and types of internal combustion engines

Nevertheless, more than 100 years of history of this type of units has made it possible to develop several main types of power plants with internal combustion of fuel. They differ from each other not only in the composition of the working mixture used, but also in design features.

Gasoline engines

As the name implies, the units of this group use various types of gasoline as fuel.

In turn, such power plants are usually divided into two large groups:

• Carburetor. In such devices, the fuel mixture before entering the cylinders is enriched with air masses in special device(carburetor). Then it is ignited by an electric spark. Among the most prominent representatives of this type can be called VAZ models, the internal combustion engines of which are very for a long time was exclusively carbureted type.
• Injection. This is a more complex system in which fuel is injected into the cylinders through a special manifold and injectors. It can happen like mechanically, as well as through a special electronic device. Common Rail direct injection systems are considered the most productive. Installed on almost everything modern cars.

Injection gasoline engines considered to be more economical and provide more high efficiency. However, the cost of such units is much higher, and maintenance and operation are much more difficult.

Diesel engines

At the dawn of the existence of units of this type, one could very often hear a joke about the internal combustion engine, that this is a device that eats gasoline like a horse, but moves much more slowly. With the invention of the diesel engine, this joke has partially lost its relevance. Mainly because diesel is able to run on fuel much more Low quality. This means that it is much cheaper than gasoline.

chief fundamental difference internal combustion is the absence of forced ignition fuel mixture. Diesel fuel is injected into the cylinders by special injectors, and individual drops of fuel are ignited due to the pressure force of the piston. Along with the benefits diesel engine also has a number of disadvantages. Among them are the following:

• much less power compared to gasoline power plants;
• large dimensions and weight characteristics;
• difficulties with starting under extreme weather and climatic conditions;
• insufficient traction and a tendency to unjustified power losses, especially at relatively high speeds.

Besides, ICE repair diesel type, as a rule, is much more complicated and costly than adjusting or restoring the performance of a gasoline unit.

gas engines

Despite the cheapness of natural gas used as fuel, the construction of gas-fired internal combustion engines is incommensurably more complicated, which leads to a significant increase in the cost of the unit as a whole, its installation and operation in particular.

In power plants of this type, liquefied or natural gas enters the cylinders through a system of special gearboxes, manifolds and nozzles. The ignition of the fuel mixture occurs in the same way as in carburetor petrol plants, - with the help of an electric spark emanating from a spark plug.

Combined types of internal combustion engines

Few people know about combined systems ICE. What is it and where is it applied?

It is, of course, not about modern hybrid cars capable of running both on fuel and on an electric motor. Combined engines Internal combustion is commonly referred to as such units that combine elements of various principles of fuel systems. Most prominent representative families of such engines are gas-diesel installations. In them, the fuel mixture enters the internal combustion engine block in almost the same way as in gas units. But the fuel is ignited not with the help of an electric discharge from a candle, but with an ignition portion of diesel fuel, as happens in a conventional diesel engine.

Maintenance and repair of internal combustion engines

Despite a fairly wide variety of modifications, all internal combustion engines have similar principal constructions and schemes. Nevertheless, in order to carry out high-quality maintenance and repair of internal combustion engines, it is necessary to thoroughly know its structure, understand the principles of operation and be able to identify problems. For this, of course, it is necessary to carefully study the design of internal combustion engines. various types, to understand for yourself the purpose of certain parts, assemblies, mechanisms and systems. This is not easy, but very exciting! And most importantly, necessary.

Especially for inquisitive minds who want to independently comprehend all the mysteries and secrets of almost any vehicle, an approximate circuit diagram ICE is shown in the photo above.

So, we found out what this power unit is.

We would like to point out that if you need any auto parts for your car, then our Internet service will be glad to offer you them at the most low prices. All you need is to go to the "" menu and fill out the form, or enter the name of the spare part in the upper right window of this page, after that our managers will contact you and offer the best prices like you have never seen or heard of before! Now to the main thing.

So, we all know that the most important part of the car is the maestro engine. The main purpose of the engine is to convert gasoline into driving force. Currently, the easiest way to get a car moving is to burn gasoline inside the engine. That is why the car engine is called internal combustion engine.

Two things to remember:

There are various internal combustion engines. For example, a diesel engine is different from a gasoline engine. Each of them has its own advantages and disadvantages.

There is such a thing as an external combustion engine. best example such an engine is steam engine steamer. Fuel (coal, wood, oil) burns outside the engine, forming steam, which is the driving force. The internal combustion engine is much more efficient (requires less fuel per kilometer). In addition, it is much smaller than the equivalent external combustion engine. This explains the fact why we do not see cars with steam engines on the streets.

The principle underlying the operation of any piston engine internal combustion: if you put a small amount of high-energy fuel (such as gasoline) into a small closed space, and ignite it, then when burned in the form of gas, an incredible amount of energy is released. If we create a continuous cycle of small explosions, the speed of which will be, for example, a hundred times a minute, and put the resulting energy in the right direction, then we will get the basis of the engine.

Almost all cars now use what is known as the four-stroke combustion cycle to convert gasoline into the driving power of a four-wheeled friend. The four-stroke approach is also known as the Otto cycle, after Nikolaus Otto, who invented it in 1867. The four strokes are:

1. intake stroke.
2. Compression stroke.
3. Burning stroke.
4. Removal of combustion products.

A device called a piston, which performs one of the main functions in the engine, replaces the potato projectile in a potato gun in a peculiar way. The piston is connected to the crankshaft by a connecting rod. As soon as the crankshaft begins to rotate, there is a "gun discharge" effect. Here's what happens when the engine goes through one cycle:

Ø The piston is on top, then opens inlet valve and the piston is lowered, while the engine is gaining full cylinder air and gasoline. This stroke is called the intake stroke. To start work, it is enough to mix air with a small drop of gasoline.

Ø The piston then moves back and compresses the mixture of air and gasoline. Compression makes the explosion more powerful.

Ø When the piston reaches its top point, the spark plug emits sparks to ignite the gasoline. An explosion of gasoline occurs in the cylinder, which causes the piston to move down.

Ø As soon as the piston reaches the bottom, the exhaust valve opens and the combustion products are expelled from the cylinder through the exhaust pipe.

The engine is now ready for the next stroke and the cycle repeats over and over again.

Now let's look at all the parts of the engine, the work of which is interconnected. Let's start with the cylinders.

The main components of the engine thanks to which it works

The base of the engine is the cylinder in which the piston moves up and down. The engine described above has one cylinder. This is true for most lawnmowers, but most vehicles have more than one cylinder (usually four, six, and eight). In multi-cylinder engines, the cylinders are usually arranged in three ways: in-line, V-shaped, and flat (also known as horizontally opposed).

Various configurations have different benefits and disadvantages in terms of smoothness, manufacturing costs and shape characteristics. These advantages and disadvantages make them more or less suitable for different types Vehicle.

Let's take a closer look at some key engine parts.

Spark plug

Spark plugs provide the spark that ignites air-fuel mixture. The spark must appear in right moment For uptime engine.

valves

The intake and exhaust valves open at a certain moment in order to let in air and fuel and release combustion products. It should be noted that both valves are closed at the moment of compression and combustion, ensuring the tightness of the combustion chamber.

Piston

A piston is a cylindrical piece of metal that moves up and down inside an engine's cylinder.

Piston rings

Piston rings provide a seal between the sliding outer edge of the piston and the inner surface of the cylinder. Rings serve two purposes:

• During the compression and combustion strokes, they prevent the air-fuel mixture and exhaust gases from escaping from the combustion chamber.
• They prevent the oil from entering the combustion zone where it will be destroyed.

If your car starts to "eat up oil" and you have to add it every 1000 kilometers, then the car's engine is quite old and the piston rings in it are very worn out. As a result, they cannot provide tightness at the proper level. And this means that you need to be puzzled by the question, because buying a new engine is a painstaking and responsible business.

connecting rod

The connecting rod connects the piston to the crankshaft. It can rotate in different sides and from both ends, because and the piston and crankshaft are in motion.

Crankshaft

In a circular motion, the crankshaft causes the piston to move up and down.

Sump

The oil sump surrounds the crankshaft. It contains some oil, which collects in the lower part of it (in the oil pan).

The main causes of malfunctions and interruptions in the machine and engine

One beautiful morning you can get into your car and realize that the morning is not so beautiful... The car won't start, the engine won't run. What could be causing this. Now that we have figured out the operation of the engine, you can understand what can cause it to fail. There are three main reasons: poor fuel mixture, no compression, or no spark. In addition, thousands of little things can cause it to malfunction, but these three form " big three". We will consider how these reasons affect the operation of the motor using an example of a very simple engine which we have already discussed earlier.

Bad fuel mixture

This problem may occur in the following cases:

You have run out of gas and only air enters the car engine, which is not enough for combustion.

Air intakes can be clogged, and the engine simply does not get air, which is essential for the combustion stroke.

· The fuel system may be supplying too little or too much fuel to the mixture, meaning that combustion does not occur properly.

· There may be impurities in the fuel (such as water in the gas tank) that prevent the fuel from burning.

No compression

If the fuel mixture cannot be compressed properly, then there will be no proper combustion process to keep the engine running. Lack of compression may occur due to the following reasons:

· The engine piston rings are worn, so the air-fuel mixture is leaking between the cylinder wall and the piston surface.

· One of the valves does not close tightly, which, again, allows the mixture to flow out.

There is a hole in the cylinder.

In most cases, "holes" in a cylinder appear where the top of the cylinder joins the cylinder itself. As a rule, there is a thin gasket between the cylinder and the cylinder head, which ensures the tightness of the structure. If the gasket breaks, holes form between the cylinder head and the cylinder itself, which also cause leakage.

No spark

The spark may be weak or absent for several reasons:

• If the spark plug or the wire leading to it is worn out, the spark will be quite weak.
• If the wire is cut or missing altogether, if the system that sends sparks down the wire is not working properly, then there will be no spark.
• If the spark enters the cycle too early, or too late, the fuel will not be able to ignite at the right time, which accordingly affects stable work motor.

Other engine problems are also possible. For example:

• If it is discharged, then the engine will not be able to make a single revolution, respectively, you will not be able to start the car.
• If the bearings that allow the crankshaft to rotate freely are worn out, the crankshaft will not be able to turn and start the engine.
• If the valves do not close or open at the right time in the cycle, the engine will not work.
• If the car runs out of oil, the pistons will not be able to move freely in the cylinder and the engine will stall.

In a properly running engine, the above problems cannot occur. If they appear, expect trouble.

As you can see, a car's engine has a number of systems that help it perform its main task - converting fuel into driving force.

Engine valve train and ignition system

Most automotive engine subsystems can be implemented through various technologies, and more advanced technologies can improve engine performance. Let's look at these subsystems used in modern cars. Let's start with valve mechanism. It consists of valves and mechanisms that open and close the passage for fuel waste. The system for opening and closing valves is called a shaft. The camshaft has lugs that move the valves up and down.

Most modern engines have so-called overhead cams. This means that the shaft is located above the valves. Shaft cams act on the valves directly or via very short links. This system is set up so that the valves are in sync with the pistons. Many high-efficiency engines have four valves per cylinder - two for air inlet and two for exhaust gases - and such arrangements require two camshafts per cylinder block.

The ignition system produces a high voltage charge and transfers it to the spark plugs using wires. First, the charge enters the distributor, which you can easily find under the hood of most cars. One wire is connected to the center of the distributor, and four, six or eight other wires come out of it (depending on the number of cylinders in the engine). These wires send a charge to each spark plug. The engine is set up so that only one cylinder at a time receives a charge from the distributor, which guarantees the smoothest possible operation of the motor.

Engine ignition, cooling and intake system

The cooling system in most vehicles consists of a radiator and a water pump. Water circulates around the cylinders through special passages, then, for cooling, it enters the radiator. In rare cases, car engines are equipped with a car air system. This makes the engines lighter, but the cooling is less efficient. As a rule, engines with this type of cooling have a shorter service life and lower performance.

Now you know how and why your car's engine cools. But why is air circulation so important? Exist automotive engine supercharged - this means that the air passes through air filters and enters directly into the cylinders. To increase performance, some engines are turbocharged, which means that the air that enters the engine is already under pressure, so more air/fuel mixture can be squeezed into the cylinder.

Improving the performance of a car is great, but what actually happens when you turn the key in the ignition and start the car? The ignition system consists of an electric motor, or starter, and a solenoid. When you turn the key in the ignition, the starter turns the engine a few revolutions to start the combustion process. Required really powerful motor, to start it cold engine. Since starting an engine requires a lot of energy, hundreds of amps must flow into the starter to start it. The solenoid is the switch that can handle that much electricity, and when you turn the ignition key, it's the solenoid that activates, which in turn fires the starter.

Engine lubricants, fuel, exhaust and electrical systems

When it comes to daily use of the car, the first thing you care about is the availability of gasoline in the gas tank. How does this gasoline actuate the cylinders? Fuel system The engine pumps gasoline out of the gas tank and mixes it with air so that the correct air-gasoline mixture enters the cylinder. Fuel is supplied in three common ways: mixture formation, fuel port injection, and direct injection.

In carburetion, a device called a carburetor adds gasoline to the air as soon as the air enters the engine.

In an injection engine, fuel is injected individually into each cylinder, either through an intake valve (fuel port injection) or directly into the cylinder (direct injection).

Oil also plays important role in the engine. Lubrication system ensures that oil is supplied to each of the moving parts of the engine for smooth operation. Pistons and bearings (which allow free rotation of the crankshaft and camshaft) - the main parts that have an increased need for oil. In most vehicles, oil is sucked in through oil pump and oil sump, passes through a filter to remove sand, then, under high pressure, is injected into the bearings and onto the cylinder walls. Then the oil flows into the oil sump, and the cycle repeats again.

Now you know a little more about the things that go into your car's engine. But let's talk about what comes out of it. Exhaust system. It is extremely simple and consists of an exhaust pipe and a muffler. If there was no muffler, you would hear the sound of all those mini-explosions that happen in the engine. The muffler dampens the sound, and the exhaust pipe removes combustion products from the car.

Now let's talk about electrical system car, which also powers it. electrical system consists of a battery and a generator alternating current. The alternator is wired to the engine and generates the electricity needed to recharge the battery. In turn, the battery provides electricity to all vehicle systems that need it.

Now you know everything about the main engine subsystems. Let's look at how you can increase the power of your car's engine.

How to increase engine performance and improve its performance?

With all the information above, you must have noticed that there is a way to make the engine run better. Car manufacturers are constantly playing with these systems with one goal in mind: to make the engine more powerful and reduce fuel consumption.

Increase in engine volume. The larger the engine size, the greater its power, because. for each revolution, the engine burns more fuel. An increase in engine volume occurs due to an increase in either the cylinders themselves or their number. Currently 12 cylinders is the limit.

Increasing the compression ratio. Until a certain point highest degree compression produces more power. However, the more you compress the air/fuel mixture, the more likely it is to ignite before the spark plug can spark. The higher the octane number of gasoline, the less the chance of pre-ignition. This is why high-performance cars need to be fueled with high-octane gasoline, since the engines of such cars use a very high compression ratio to obtain more power.

Greater filling of the cylinder. If more air (and therefore fuel) can be squeezed into a certain size cylinder, then you can get more power from each cylinder. Turbos and superchargers pressurize air and force it into the cylinder efficiently.

Cooling of the incoming air. Compressing air raises its temperature. However, I would like to have as much as possible cold air in the cylinder, because The higher the air temperature, the more it expands when burned. Therefore, many turbocharging and supercharging systems have an intercooler. An intercooler is a radiator through which compressed air passes and is cooled before entering the cylinder.

Reduce the weight of parts. The lighter the part of the engine, the better it works. Every time the piston changes direction, it expends energy to stop. The lighter the piston, the less energy it consumes.

Fuel injection. The fuel injection system allows very precise dosing of the fuel that enters each cylinder. This improves engine performance and significantly saves fuel.

Now you know almost everything about how the car engine works, as well as the causes of the main problems and interruptions in the car. We remind you that if, after reading this article, you feel that your car requires updating any auto parts, we recommend that you order and buy them through our online service by filling out the request form in the " " menu, or by filling in the name of the spare part in the upper right window of this page. We hope that our article is about how a car engine works? As well as the main causes of malfunctions and interruptions in the car will help you make the right purchase.

The internal combustion engine is the main type of automotive power units today. The principle of operation of an internal combustion engine is based on the effect of thermal expansion of gases that occurs during combustion in the cylinder of the fuel-air mixture.

The most common types of engines

There are three types of internal combustion engines: piston, rotary-piston power unit of the Wankel system and gas turbine. With rare exceptions, modern cars are equipped with four-stroke piston engines. The reason lies in the low price, compactness, low weight, multi-fuel capacity and the ability to install on almost any vehicle.

The car engine itself is a mechanism that converts the thermal energy of burning fuel into mechanical energy, the operation of which is provided by many systems, components and assemblies. Piston internal combustion engines are two- and four-stroke. It is easiest to understand the principle of operation of a car engine using the example of a four-stroke single-cylinder power unit.

It is called a four-stroke engine because one working cycle consists of four piston movements (strokes) or two revolutions of the crankshaft:

• inlet;
• compression;
• work stroke;
• release.

General ICE device

To understand the principle of operation of the motor, it is necessary in in general terms imagine his device. The main parts are:

1. cylinder block (in our case, there is only one cylinder);
2. crank mechanism, consisting of a crankshaft, connecting rods and pistons;
3. block head with a gas distribution mechanism (timing).

The crank mechanism provides the conversion of the reciprocating motion of the pistons into the rotation of the crankshaft. The pistons are set in motion thanks to the energy of the fuel burning in the cylinders.


Job this mechanism is impossible without the operation of the gas distribution mechanism, which ensures the timely opening of the intake and exhaust valves for the intake of the working mixture and the exhaust gases. Timing consists of one or more camshafts, having cams pushing valves (at least two for each cylinder), valves and return springs.

The internal combustion engine is able to work only with the coordinated work of auxiliary systems, which include:

• ignition system responsible for igniting the combustible mixture in the cylinders;
• an intake system that provides air supply for the formation of a working mixture;
• a fuel system that provides a continuous supply of fuel and obtaining a mixture of fuel with air;
• lubrication system designed to lubricate rubbing parts and remove wear products;
• exhaust system, which removes exhaust gases from ICE cylinders and reducing their toxicity;
• the cooling system necessary to maintain the optimum temperature for the operation of the power unit.

Motor duty cycle

As mentioned above, the cycle consists of four measures. During the first stroke, the camshaft cam pushes the intake valve, opening it, the piston begins to move from the extreme top position down. At the same time, a vacuum is created in the cylinder, due to which the finished product enters the cylinder. working mixture, or air, if the internal combustion engine is equipped with a direct fuel injection system (in this case, the fuel is mixed with air directly in the combustion chamber).

The piston communicates movement to the crankshaft through the connecting rod, turning it 180 degrees by the time it reaches its lowest position.

During the second stroke - compression - the inlet valve (or valves) closes, the piston reverses its direction of movement, compressing and heating the working mixture or air. At the end of the cycle, the ignition system supplies the spark plug with electrical discharge, and a spark is formed, igniting the compressed air-fuel mixture.

The principle of fuel ignition diesel internal combustion engine another: at the end of the compression stroke, through the nozzle, finely atomized diesel fuel is injected into the combustion chamber, where it mixes with heated air, and the resulting mixture ignites spontaneously. It should be noted that for this reason, the compression ratio of a diesel engine is much higher.

The crankshaft, meanwhile, turned another 180 degrees, making one complete revolution.

The third cycle is called the working stroke. The gases formed during the combustion of fuel, expanding, push the piston to its lowest position. The piston transfers energy to the crankshaft through the connecting rod and turns it another half turn.

Upon reaching the bottom dead center the final cycle begins - release. At the beginning of this measure, the cam camshaft pushes and opens Exhaust valve, the piston moves up and pushes the exhaust gases out of the cylinder.

Internal combustion engines installed on modern cars have not one cylinder, but several. For uniform operation of the engine at the same time, different cycles are performed in different cylinders, and every half-turn of the crankshaft, a working stroke occurs in at least one cylinder (the exception is 2- and 3-cylinder engines). Thanks to this, it is possible to get rid of unnecessary vibrations, balancing the forces acting on the crankshaft and ensuring smooth operation of the internal combustion engine. The connecting rod journals are located on the shaft at equal angles relative to each other.

For reasons of compactness, multi-cylinder engines are made not in-line, but V-shaped or boxer (Subaru's business card). This saves a lot of space under the hood.

Two stroke motors

In addition to four-stroke piston internal combustion engines, there are two-stroke ones. The principle of their work is somewhat different from that described above. The device of such a motor is simpler. The cylinder has for the window - inlet and outlet, located above. The piston, being at BDC, closes the inlet window, then, moving up, closes the outlet and compresses the working mixture. When it reaches TDC, a spark forms on the candle and ignites the mixture. At this time, the inlet window is open, and through it the next dose of the fuel-air mixture enters the crank chamber.

During the second stroke, moving down under the influence of gases, the piston opens the outlet window, through which the exhaust gases are blown out of the cylinder with a new portion of the working mixture, which enters the cylinder through the purge channel. At the same time, part of the working mixture also goes into the exhaust window, which explains the voracity of a two-stroke internal combustion engine.

This principle of operation allows you to achieve more engine power with a smaller displacement, but you have to pay for this with high fuel consumption. The advantages of such motors include more uniform operation, simple design, low weight and high power density. Among the shortcomings, mention should be made of a dirtier exhaust, the lack of lubrication and cooling systems, which threatens to overheat and the unit fails.

On our roads, most often you can find cars that consume gasoline and diesel fuel. The time for electric cars has not yet come. Therefore, consider the principle of operation of an internal combustion engine (ICE). hallmark his is the transformation of the energy of the explosion into mechanical energy.

When working with gasoline power plants, there are several ways to form the fuel mixture. In one case, this happens in the carburetor, and then it's all fed into the engine cylinders. In another case, gasoline is injected through special nozzles (injectors) directly into the manifold or combustion chamber.

For full understanding operation of the internal combustion engine, you need to know that there are several types modern motors that have proven their effectiveness in the work:

• gasoline engines;
• engines consuming diesel fuel;
• gas installations;
• gas-diesel devices;
• rotary options.

The principle of operation of these types of internal combustion engines is almost the same.

ICE cycles

Each has fuel that explodes in the combustion chamber, expands and pushes a piston mounted on a crankshaft. Further, this rotation is transmitted to the wheels of the car through additional mechanisms and nodes.

As an example, we will consider gasoline four stroke motor, because it is the most common power plant in cars on our roads.

So you:

1. the intake opening opens and the combustion chamber is filled with the prepared fuel mixture
2. the chamber is sealed and its volume decreases in the compression stroke
3. the mixture explodes and pushes the piston, which receives an impulse of mechanical energy
4. the combustion chamber is freed from combustion products

Each of these stages of the work of the internal combustion engine has its own, several simultaneous processes take place. In the first case, the piston is in its lowest position, while all valves that inlet fuel are open. The next stage begins with the complete closing of all holes and the movement of the piston to the maximum upper position. At the same time, everything is compressed.

Reaching the extreme top position of the piston again, voltage is applied to the candle, and it creates a spark, igniting the mixture for an explosion. The force of this explosion pushes the piston down, while the outlet openings open and the chamber is cleared of residual gas. Then everything repeats.

Carburetor operation

The formation of the fuel mixture in the cars of the first half of the last century took place with the help of a carburetor. To understand how an internal combustion engine works, you need to know that automotive engineers designed fuel system so that the already prepared mixture was fed into the combustion chamber.

Carburetor device

The carburetor was engaged in its formation. He mixed gasoline and air in the right proportions and sent it all to the cylinders. Such a relative simplicity of the system design allowed it to remain an indispensable part of the system for a long time. gasoline units. But later, its shortcomings began to prevail over the merits and did not meet the increasing requirements for cars in general.

Disadvantages of carburetor systems:

• it is not possible to provide economical modes with sudden changes in driving modes;
• exceeding limits harmful substances in exhaust gases;
• low power of cars due to inconsistency of the prepared mixture with the condition of the car.

They tried to compensate for these shortcomings by direct supply of gasoline through the injectors.

The operation of injection engines

The principle of operation of the injection engine is direct injection gasoline during intake manifold or combustion chamber. Visually, everything is similar to the operation of a diesel installation, when the supply is metered and only into the cylinder. The only difference is that the injection units spark plugs installed.

Injector design

Stages of work gasoline engines with direct injection do not differ from the carburetor version. The difference is only in the place where the mixture is formed.

Due to this design option, the advantages of such engines are provided:

• power increase up to 10% with similar technical specifications with carburetor;
• noticeable savings in gasoline;
• improvement of environmental performance in terms of emissions.

But with such advantages, there are also disadvantages. The main ones are maintenance, maintainability and customization. Unlike carburetors, which can be disassembled, assembled and adjusted independently, injectors require special expensive equipment and a large number of different sensors installed in the car.

Fuel injection methods

In the course of the evolution of the fuel supply to the engine, this process has been constantly approaching the combustion chamber. In the most modern internal combustion engines there was a merger of the point of supply of gasoline and the place of combustion. Now the mixture is no longer formed in the carburetor or intake manifold, but is injected directly into the chamber. Consider all options for injection devices.

Single point injection option

The simplest design option looks like fuel injection through a single nozzle into the intake manifold. The difference with the carburetor is that the latter delivers the finished mixture. In the injection version, fuel is supplied through the nozzle. The benefit is to save on costs.

Single point fuel supply option

This method also forms the mixture outside the chamber, but here sensors are involved that provide supply directly to each cylinder through the intake manifold. This is a more economical option for using fuel.

Direct injection into the chamber

This variant so far uses the possibilities of the injector design most effectively. The fuel is directly sprayed into the chamber. Due to this, the level of harmful emissions is reduced, and the car receives, in addition to greater gasoline savings, increased power.

The increased degree of system reliability reduces the negative factor regarding maintenance. But such devices need high-quality fuel.