Internal combustion engine and electric motor. The principle of operation of the internal combustion engine

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

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 steamships is the best example of an external combustion engine. Fuel (coal, wood, oil, any other) in steam engine burns outside the engine to create steam, and the steam creates motion inside the engine. Of course, the internal combustion engine is much more efficient (at least consumes much less fuel per kilometer of the vehicle) than an external combustion engine, in addition, an internal combustion engine is much smaller than an equivalent external combustion engine in terms of power. 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 internal combustion engine: if you put a small amount of high-energy fuel (such as gasoline) in a small enclosed space and ignite it (that fuel), an incredible amount of energy is released in the form of 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- Inlet 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, a car for comfortable ride it needs at least 3 more of these cylinders with pistons and all the attributes necessary for this couple (valves, connecting rods, and so on), but one cylinder is only suitable 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

Different configurations have different advantages and disadvantages in terms of vibration, production cost, and shape characteristics. These advantages and disadvantages make them more suitable for certain specific vehicles. 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 a V-shaped arrangement of 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 thousands of other minor things that can create problems, but these "big three" are most often the result or cause of one of them. Based on a simple idea of ​​how the engine works, 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.
• Fuel system may supply 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 to 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.

Majority modern engines have what they call overhead cams. This means that the shaft is located above the valves, as you can see in the picture. Older engines use a 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. 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 produces a charge high voltage and transmits it to the spark plugs via 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 cool.

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! launch 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 only turning the key to reverse side when the spark is no longer supplied to the cylinders, and the engine thus stalls.

The starter has powerful electric motor, which rotates cold engine internal combustion. 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 the resistance of the water pump, 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 to daily car maintenance, your first concern is probably to check the amount of gas in your car. How does gasoline get from fuel tank into cylinders? The engine's fuel system sucks gasoline out of the tank with the help of a fuel pump located 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 injection fuel).

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 all unused fuel and some other chemicals in exhaust gases. Thus, your car meets certain European standards for air pollution.

What else is there besides all of the above in the car? The electrical system consists of a battery and a generator. The generator is connected to the engine by a belt and generates electricity to charge the battery. The battery provides a 12-volt charge of electrical energy, available to everything in the car that needs electricity (ignition system, radio,

The liquid fuel internal combustion engine, developed and first put into practice in the second half of the 19th century, was the second in history, after the steam engine, an example of creating a unit that converts energy into useful work. Without this invention, it is impossible to imagine modern civilization, because vehicles with internal combustion engines of various types are widely used in any industry that ensures human existence.

Transport, powered by the internal combustion engine, plays a decisive role in the world's logistics system, which is becoming more and more important against the backdrop of globalization processes.

All modern vehicles can be divided into three large groups, depending on the type of engine used. The first group of vehicles uses electric motors. This includes the usual urban public transport - trolleybuses and trams, and electric trains with electric vehicles, and huge ships and ships that use nuclear energy - after all, modern icebreakers, nuclear submarines, and aircraft carriers of NATO countries use electric motors. The second group is equipment equipped with jet engines.

Of course, this type of engine is used mainly in aviation. The most numerous, familiar and significant is the third group of vehicles, which uses internal combustion engines. This is the largest group in terms of quantity, diversity, and influence on the economic life of a person. The principle of operation of the internal combustion engine is the same for any vehicle equipped with such an engine. What is it?

As you know, energy does not come from anywhere and does not go anywhere. The principle of operation of a car engine is fully based on this postulate of the law of conservation of energy.

In the most generalized terms, we can say that to perform useful work, the energy of molecular bonds of liquid fuel burned during engine operation is used.

The spread of liquid-fueled internal combustion engines was facilitated by several unique properties of the fuel itself. This:

• high potential energy of molecular bonds used as a fuel mixture of light hydrocarbons "for example, gasoline"
• quite simple and safe, in comparison, for example, with atomic energy, the way to release it
• relative abundance of light hydrocarbons on our planet
• the natural state of aggregation of such fuel, which makes it convenient to store and transport it.

Another the most important factor is that oxygen, of which more than 20 percent consists of the atmosphere, acts as an oxidizing agent necessary for the process of energy release. This eliminates the need to carry not only a supply of fuel, but also a supply of catalyst.

Ideally, all molecules of a certain volume of fuel and all molecules of a certain volume of oxygen should react. For gasoline, these figures correlate as 1 to 14.7, i.e., almost 15 kg of oxygen is needed to burn a kilogram of fuel. However, such a process, called stoichiometric, is unrealizable in practice. In reality, there is always some portion of the fuel that is not combined with oxygen during the course of the reaction.

Moreover, for certain modes of operation of the internal combustion engine, stoichiometry is even harmful.

Now that the chemical process is understood in general terms, it is worth considering the mechanics of the process of converting fuel energy into useful work, using the example of a four-stroke internal combustion engine operating on the so-called Otto cycle.

The most famous and what is called the classic work cycle is the four-part engine operation process patented back in 1876 by Nikolaus Otto. "cycles, hence the four-stroke internal combustion engines." The first stroke is the creation by the piston of a vacuum in the cylinder by its own movement under the influence of weight. As a result, the cylinder is filled with a mixture of oxygen and gasoline vapors "nature abhors a vacuum." The piston continuing to move compresses the mixture - we get the second cycle. On the third stroke, the mixture ignites "Otto used a conventional burner, now the spark plug is responsible for this."

The ignition of the mixture creates the release of a large amount of gas, which presses on the piston and causes it to rise - to perform useful work. The fourth stroke is the opening of the exhaust valve and the displacement of combustion products by the returning piston.

Thus, only starting the engine requires external influence - cranking the crankshaft connected to the piston. Now this is done using the power of electricity, and on the first cars the crankshaft had to be cranked by hand "the same principle is used in cars that have a forced manual start of the engine."

Since the release of the first cars, many engineers have tried to invent a new cycle of operation of the internal combustion engine. At first, this was due to the effect of the patent, which many wanted to get around.

As a result, already at the beginning of the last century, the Atkinson cycle was created, which changed the design of the engine in such a way that all piston movements were performed in one revolution of the crankshaft. This made it possible to increase the efficiency of the engine, but reduced its power. In addition, an engine operating on such a cycle does not need a separate camshaft and reducer. However, this engine was not widely used due to a decrease in the power of the unit and a rather complex design.

Instead, modern cars often use the Miller cycle.

If Atkinson reduced the compression stroke, increasing efficiency, but considerably complicating the operation of the engine, then Miller suggested reducing the intake stroke. This made it possible to reduce the actual compression time of the mixture without reducing its geometric compression. Thus, the efficiency of each cycle of the internal combustion engine increases, thereby reducing the consumption of fuel burned "for nothing".

However, most engines operate on the Otto cycle, so it is necessary to consider it in more detail.

Even the simplest ICE variant includes fourteen essential elements required for its operation. Each element has specific functions.

Thus, the cylinder performs a dual role - it is activated air mixture and the piston moves. In the part called the combustion chamber, a candle is installed, and two valves, one of which blocks the flow of fuel, the other - the exhaust gases.

A candle is a device that ignites the mixture with the required cyclicity. In fact, it is a device for obtaining a sufficiently powerful electric arc for a short period of time.

The piston moves in the cylinder under the influence of expanding gases or from the action of the crankshaft transmitted through the crank mechanism. In the first case, the piston converts the energy of fuel combustion into mechanical work, in the second case, it compresses the mixture for better ignition or creates pressure to remove the spent mixture residues from the cylinder.

The crank mechanism transmits torque from the piston to the shaft and vice versa. The crankshaft, due to its design, transforms the translational "up and down" movement of the piston into rotational.

The inlet port, in which the inlet valve is located, ensures that the mixture enters the cylinder. The valve ensures the cyclic flow of the mixture.

The exhaust valve, respectively, removes the accumulated combustion products of the mixture. To provide normal operation engine at the time of pressurization and ignition of the mixture, it is closed.

The operation of a gasoline engine. Detailed analysis

During the suction stroke, the piston moves down. At the same time, the intake valve opens and fuel enters the cylinder. Thus, in the cylinder is air-fuel mixture. In certain types gasoline engines this mixture is prepared in a special device - a carburetor, in others the mixing takes place directly in the cylinder.

Then the piston starts to rise. At the same time, the intake valve closes, which ensures that sufficient high pressure inside the cylinder. When the piston reaches its highest point, the entire fuel-air mixture is compressed in a part of the cylinder called the combustion chamber. At this moment, the candle gives an electric spark, and the mixture ignites.

As a result of the combustion of the mixture, a large amount of gases are released, which, trying to fill the entire volume provided, put pressure on the piston, causing it to fall. This work of the piston is transmitted by means of a crank mechanism to the shaft, which begins to rotate and rotate the wheel drive of the car.

As soon as the piston completes its downward movement, the exhaust manifold valve opens.

The remaining gases rush there, as they are pressed by a piston going up under the influence of the shaft. The cycle is over, then the piston goes down again, starting a new cycle.

As you can see, only one phase of the cycle does useful work. The remaining phases are the work of the engine “for itself”. Even this state of affairs makes the internal combustion engine one of the most efficient systems introduced into production. At the same time, the possibility of reducing "idle" in terms of efficiency cycles leads to the emergence of new, more economical systems. In addition, engines are being developed and implemented to a limited extent, which are generally devoid of a piston system. For example, some Japanese cars equipped rotary engines having a higher coefficient useful action.

At the same time, such engines have a number of disadvantages associated mainly with the high cost of production and the complexity of maintaining such engines.

Supply system

In order for the combustible mixture entering the combustion chamber to be burned correctly and ensure the smooth operation of the engine, it must be introduced in clearly measured portions and be properly prepared. For this purpose, the fuel system serves, the most important parts of which are a gas tank, a fuel line, fuel pumps, a device for mixing fuel and air, a manifold, various filters and sensors.

It is clear that the purpose of the gas tank is to store required amount fuel. Water fuels are used as pipelines for pumping with a gasoline pump, gasoline and air filters are needed to prevent clogging of thin manifolds, valves and fuel lines.

It is worth dwelling on the work of the carburetor in more detail. Despite the fact that cars with such devices are no longer produced, many cars with a carburetor type of engine are still in operation in many countries of the world. The carburetor mixes fuel with air in the following way.

The float chamber supports constant level fuel and pressure thanks to a balancing hole that bleeds excess air and a float that opens the fuel line valve as soon as the fuel level in the carburetor chamber drops. The carburetor is connected to the cylinder through a jet and a diffuser. When the pressure in the cylinder decreases, a precisely measured amount of fuel thanks to the jet rushes into the diffuser of the air chamber.

Here, due to the very small diameter of the hole, it passes into the cylinder under high pressure, gasoline is mixed with atmospheric air passed through the filter, and the resulting mixture enters the combustion chamber.

The problem with carburetor systems is the inability to accurately measure the amount of fuel and air entering the cylinder. Therefore, all modern cars are equipped with an injection system, also called injection.

In an injection engine, instead of a carburetor, injection is carried out by a nozzle or nozzles - a special mechanical atomizer, the most important part of which is a solenoid valve. These devices, especially when paired with special computing microchips, allow you to inject a precisely measured amount of fuel at the right time. As a result, the engine runs smoother, starts easier and consumes less fuel.

Gas distribution mechanism

It is clear how the carburetor prepares a combustible mixture of gasoline and air. But how do the valves that ensure the timely supply of this mixture to the cylinder work? The gas distribution mechanism is responsible for this. It is he who performs the timely opening and closing of the valves, and also provides the necessary duration and height of their rise.

It is these three parameters that together are the gas distribution phases.

Modern engines have special device to change these phases, called internal combustion engine phase shifter the principle of operation of which is based on turning the camshaft if necessary. This clutch, with an increase in the amount of injected fuel, turns the camshaft at a certain angle in the direction of rotation. This change in its position causes the intake valves to open earlier and the combustion chambers to fill with mixture better, compensating for the ever-increasing power demand. The most technically advanced models have several of these clutches, they are controlled by fairly sophisticated electronics and can regulate not only the valve opening frequency, but also its stroke, which has a great effect on engine operation at maximum speed.

The principle of operation of the engine cooling system

Of course, not all of the released bond energy of fuel molecules is converted into useful work. Most of it is lost, turning into heat, and friction engine parts also generates heat energy. Excess heat must be removed. That is the purpose of the cooling system.

Separate the air system, liquid and combined. The most common liquid cooling system, although there are cars with air - it was used to simplify the design and reduce the cost budget cars, or to reduce weight, if it was a sports car.

The main elements of the system are represented by a heat exchanger, a radiator, a centrifugal pump, expansion tank and thermostat. In addition, the cooling system includes oil radiator, radiator fan, coolant temperature sensor.

The liquid circulates through the heat exchanger under the influence of the pump, removing the temperature from the engine. Until the engine warms up, a special valve closes the radiator - this is called the "small circle" of movement. This operation of the system allows you to quickly warm up the engine.

As soon as the temperature rises to the operating temperature, the temperature sensor gives the command to open the valve, and the coolant begins to move through the radiator. The thin tubes of this unit are blown by a stylish flow of headwind, thus cooling the liquid, which again enters the collector, starting the cooling cycle anew.

If the influence of the ram air is not enough to normal cooling- the car is working with a significant load, moving with low speed or the weather is very hot, the cooling fan turns on. It blows over the radiator, forcibly cooling the working fluid.

Turbocharged machines have two cooling circuits. One is for cooling the internal combustion engine directly, the second is for removing excess heat from the turbine.

Electrician

The first cars made do with a minimum of electrics. IN modern machines appears more and more electrical circuits. Electricity is consumed by the fuel supply system, ignition, cooling and heating system, and lighting. In the presence of a lot of energy, the air conditioning system, engine management, electronic systems security. Components such as the starting system and glow plugs consume energy in a short time, but in large quantities.

To provide all these elements with the necessary electricity, current sources are used, electrical wiring, controls and fuse boxes.

The current source of the car is a battery that is paired with a generator. When the engine is running, the shaft drive turns the generator, which generates the necessary energy.

The generator works by converting the rotational energy of the shaft into electrical energy using the principles of electromagnetic induction. In order to start the internal combustion engine, the energy of the battery is used.

During starting, the main consumer of energy is the starter. This device is a motor direct current, designed to scroll the crankshaft, providing the start of the internal combustion engine operation cycle. The principle of operation of a DC motor is based on the interaction that occurs between the magnetic field generated in the stator and the current flowing in the rotor. This force affects the rotor, which begins to rotate, and its rotation coincides with the rotation of the magnetic field characteristic of the stator. Thus, electrical energy is converted into mechanical energy, and the starter begins to spin the engine shaft. As soon as the engine starts and the generator starts to work, the battery stops producing energy and begins to store it. If the generator is not working or for some reason its power is not enough, the battery continues to give energy and discharge.

This type of engine is also an internal combustion engine, but has distinctive features, which make it possible to sharply separate engines operating on the principle invented by Rudolf Diesel from other internal combustion engines operating on “light” fuels such as gasoline “in motoring” or kerosene “in aviation”.

The difference in the fuel used predetermines the design differences. The fact is that it is relatively difficult to set fire to diesel fuel and achieve its instantaneous combustion under normal conditions, so the ignition method from a candle is not suitable for this fuel. The ignition of a diesel engine is carried out due to its contact with air heated to a very high temperature. For this purpose, the property of gases to heat up during compression is used. Therefore, the piston working on diesel ICE compresses air, not fuel. When the compression ratio reaches its maximum, and the piston itself reaches its highest point, the “electromagnetic pump” nozzle instead of a candle injects dispersed fuel. It reacts with hot oxygen and ignites. Further work occurs, which is also characteristic of a gasoline internal combustion engine.

Wherein internal combustion engine power does not change by the proportion of the mixture of air and fuel, as in gasoline engines, but solely by the amount of injected diesel, while the amount of air is constant and does not change. At the same time, the principle of operation of a modern gasoline unit equipped with a nozzle is absolutely not similar to the principle of operation of a diesel internal combustion engine.

Gasoline operated electromechanical spray pumps are primarily designed to more accurately measure the injected fuel, and interact with the spark plugs. In what these two types of internal combustion engines are similar is in the increased demands on fuel quality.

Since the air pressure created by the piston diesel engine, much higher than the pressure exerted by a compressed air-gasoline mixture, such an engine is more demanding on the gaps between the piston and the cylinder walls. In addition, it is more difficult to start a diesel engine in winter, since diesel fuel thickens under the influence of low temperature indicators, and the nozzle cannot spray it with sufficient quality.

Both a modern gasoline engine and its diesel “relative” are extremely reluctant to run on “DT” gasoline of inadequate quality, and even its short-term use is fraught with serious problems with the fuel system.

Modern internal combustion engines are the most efficient devices for converting thermal energy into mechanical energy. Despite the fact that most of the energy is spent not on directly useful work, but on maintaining the cycle of the engine itself, mankind has not yet learned how to mass-produce devices that would be more practical, more powerful, more economical and more convenient than internal combustion engines. At the same time, the rise in the cost of hydrocarbon energy carriers and concern for environment forced to look for new engine options for passenger cars and public transport. most promising for this moment looks like the use of autonomous, equipped with batteries large capacity, electric motors, which are much more efficient, and hybrids of such motors with petrol variants. After all, the time will surely come when it will become absolutely unprofitable to use hydrocarbons to propel personal vehicles, and internal combustion engines will take their place on museum shelves, like locomotive engines - half a century ago.

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. At present, the most in a simple way to make the car move, 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 the steam engine of a steamboat. Fuel (coal, wood, oil) burns outside the engine, forming steam, which is the driving force. An 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 the intake valve opens and the piston goes down, while the engine gains 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).

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

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 come at the 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 air leakage fuel mixture and exhaust gases 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 piston rings it is heavily 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 directions 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 fine 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 can occur for 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, then 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 in right moment, which consequently 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 subsystems car motor can be implemented through various technologies, and more advanced technologies can improve the efficiency of the engine. Let's take a look at these subsystems used in modern cars. Let's start with the valve train. 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 air system car. 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? There are supercharged car engines - this means that the air passes through the 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 a 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 an 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 the crankshaft and camshaft to rotate freely) are the main parts that have an increased need for oil. In most vehicles, oil is sucked in through an oil pump and sump, passed through a filter to get rid of sand, then injected under high pressure 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 exhaust pipe removes combustion products from the vehicle.

Now let's talk about electrical system car, which also powers it. The 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. Up to a point, a higher compression ratio 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 rating of the gasoline, the less chance of pre-ignition. This is why high-performance cars need to be fueled with high-octane gasoline, as the engines in these cars use a very high compression ratio to produce more power.

More 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 and cools 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.

Most drivers have no idea what a car engine is. And it is necessary to know this, because it is not in vain that when studying in many driving schools, students are told the principle of operation of internal combustion engines. Every driver should have an idea about the operation of the engine, because this knowledge can be useful on the road.

Of course there are different types and brands of car engines, the operation of which differs in details (fuel injection systems, cylinder arrangement, etc.). However, the basic principle for all ICE types remains unchanged.

The device of a car engine in theory

It is always appropriate to consider the internal combustion engine device using the example of the operation of one cylinder. Although most often cars have 4, 6, 8 cylinders. In any case, the main part of the motor is the cylinder. It contains a piston that can move up and down. At the same time, there are 2 boundaries of its movement - upper and lower. Professionals call them TDC and BDC (top and bottom dead center).

The piston itself is connected to the connecting rod, and the connecting rod is connected to the crankshaft. When the piston moves up and down, the connecting rod transfers the load to the crankshaft, and it rotates. The loads from the shaft are transferred to the wheels, causing the car to start moving.

But the main task is to make the piston work, because it is he who is the main driving force of this complex mechanism. This is done using gasoline, diesel fuel or gas. A drop of fuel ignited in the combustion chamber pushes the piston back great strength down, thereby setting it in motion. Then, by inertia, the piston returns to the upper limit, where the explosion of gasoline again occurs and this cycle is repeated constantly until the driver turns off the engine.

This is what a car engine looks like. However, this is just a theory. Let's take a closer look at the cycles of the motor.

Four stroke cycle

Almost all engines operate on a 4-stroke cycle:

1. Fuel inlet.
2. Fuel compression.
3. Combustion.
4. Output of exhaust gases outside the combustion chamber.

Scheme

The figure below shows typical circuit car engine devices (one cylinder).

This diagram clearly shows the main elements:

A - Camshaft.

B - Valve cover.

C - Exhaust valve through which gases are removed from the combustion chamber.

D - Exhaust port.

E - Cylinder head.

F - Coolant chamber. Most often there is antifreeze, which cools the heating motor housing.

G - Motor block.

H - Oil sump.

I - Pan where all the oil flows.

J - A spark plug that generates a spark to ignite the fuel mixture.

K - The intake valve through which the fuel mixture enters the combustion chamber.

L - Inlet.

M - A piston that moves up and down.

N - Connecting rod connected to the piston. This is the main element that transmits force to the crankshaft and transforms the linear movement (up and down) into rotational.

O - Connecting rod bearing.

P - Crankshaft. It rotates due to the movement of the piston.

It is also worth highlighting such an element as piston rings (they are also called oil scraper rings). They are not shown in the figure, but they are an important component of the car engine system. These rings wrap around the piston and create a maximum seal between the walls of the cylinder and the piston. They prevent fuel from entering the oil pan and oil from entering the combustion chamber. Most of the old VAZ car engines and even motors European manufacturers have worn rings that do not create an effective seal between the piston and cylinder, which can allow oil to enter the combustion chamber. In such a situation, there will be an increased consumption of gasoline and "zhor" oil.

These are the basic design elements that take place in all internal combustion engines. In fact, there are many more elements, but we will not touch on the subtleties.

How does an engine work?

Let's start with the initial position of the piston - it is at the top. At this point, the inlet port is opened by a valve, the piston begins to move down and sucks the fuel mixture into the cylinder. In this case, only a small drop of gasoline enters the cylinder capacity. This is the first cycle of work.

During the second stroke, the piston reaches its lowest point, while the inlet closes, the piston begins to move upward, as a result of which the fuel mixture is compressed, since it has nowhere to go in a closed chamber. When the piston reaches its maximum upper point, the fuel mixture is compressed to its maximum.

The third stage is the ignition of the compressed fuel mixture using a spark plug that emits a spark. As a result, the combustible composition explodes and pushes the piston down with great force.

At the final stage, the part reaches the lower boundary and returns to the upper point by inertia. Opens at this time Exhaust valve, the exhaust mixture in the form of gas leaves the combustion chamber and enters the street through the exhaust system. After that, the cycle, starting from the first stage, repeats again and continues for the entire time until the driver turns off the engine.

As a result of the explosion of gasoline, the piston moves down and pushes the crankshaft. It spins and transfers the load to the wheels of the car. This is what a car engine looks like.

Differences in gasoline engines

The method described above is universal. The work of almost all gasoline engines. Diesel engines are distinguished by the fact that there are no candles - an element that ignites the fuel. Detonation of diesel fuel is carried out due to the strong compression of the fuel mixture. That is, in the third cycle, the piston rises, strongly compresses the fuel mixture, and it explodes naturally under pressure.

ICE alternative

It should be noted that recently electric cars have appeared on the market - cars with electric motors. There, the principle of operation of the motor is completely different, since the source of energy is not gasoline, but electricity in batteries. But for now automotive market belongs to cars with internal combustion engines, and electric motors cannot boast of high efficiency.

A few words in conclusion

Such an internal combustion engine device is almost perfect. But every year new technologies are being developed that increase the efficiency of the engine, and the characteristics of gasoline are improved. With the right maintenance car engine, it can work for decades. Some successful engines of Japanese and German concerns"run" a million kilometers and become unusable solely due to mechanical obsolescence of parts and friction pairs. But many engines, even after a million run, successfully undergo overhaul and continue to fulfill their intended purpose.

The internal combustion engine (ICE) is by far the most common type of engine. The list of vehicles in which it is installed is simply huge. ICE can be found on cars, helicopters, tanks, tractors, boats, etc.

An internal combustion engine is a heat engine that converts part of the chemical energy of a burning fuel into mechanical energy. An essential division of engines into categories is the division according to the operating cycle into 2-stroke and 4-stroke; by cooking method combustible mixture- with external (in particular carburetor) and internal (for example diesel engines) mixture formation; According to the type of energy converter, internal combustion engines are divided into piston, turbine, jet and combined.

The efficiency of the internal combustion engine is 0.4-0.5. The first internal combustion engine was designed by E. Lenoir in 1860. In this article, we will consider the four-stroke internal combustion engine most commonly used in the automotive industry.

The four-stroke engine was first introduced by Nikolaus Otto in 1876 and is therefore also called the Otto cycle engine. A more literate name for such a cycle is a four-stroke cycle. It is currently the most common type of engine for cars.

The principle of operation of the internal combustion engine (ICE)

The action of a piston internal combustion engine is based on the use of thermal expansion pressure of heated gases during piston movement. Heating of gases occurs as a result of combustion in the cylinder of the fuel-air mixture. To repeat the cycle, the exhaust gas mixture must be released at the end of the piston movement and filled with a new portion of fuel and air. IN extreme position fuel is ignited by a spark plug. The intake and exhaust of fuel and combustion products occur through valves controlled by the gas distribution mechanism and the fuel supply system.

Thus, the engine operation cycle is divided into the following stages:

• intake stroke.
• Compression stroke.
• The expansion stroke, or work stroke.
• Release stroke.

The force from the moving piston of the cylinder through the crankshaft is converted into rotational motion of the engine shaft. Part of the rotational energy is spent on returning the pistons to their original state, to complete a new cycle. The design of the shaft determines the different positions of the pistons in different cylinders at any given moment in time. Thus, the more cylinders in the engine, the more general case, the rotation of its shaft is more uniform.

According to the location of the cylinders, engines are divided into several types:

a) Engines with vertical or inclined arrangement of cylinders in one row

B) V-shaped with the mutual arrangement of cylinders at an angle in the form of the Latin letter V:

D) Engines with opposed cylinders. It is called "opposite", the cylinders in it are located at an angle of 180 degrees:

The gas distribution mechanism of the engine on the exhaust stroke ensures that the cylinders are cleaned of combustion products (exhaust gases) and the cylinders are filled with a new portion of the fuel-air mixture at the intake stroke.

The ignition system generates a high voltage discharge and transmits it to the cylinder spark plug through high voltage wire. The ignition is controlled by a distributor, the wires from which are suitable for each candle. The distributor is designed in such a way that the discharge occurs precisely in the cylinder where the piston is currently passing the point of greatest compression of the fuel mixture. If the mixture ignites earlier, then the gas pressure will work against its course, if later, the power released by the expansion of gases will not be fully used.

To start the engine, it must be given the initial movement. For this, the start system is used (see the article "how the starter works") from electric motor- starter.

Benefits of gasoline engines

• More low level noise and vibration compared to diesel;
• Great power with equal engine size;
• Ability to work on high revs, without serious consequences for the engine.

Disadvantages of gasoline engines

• Greater than diesel fuel consumption, and higher requirements for its quality;
• The need for and permanent job fuel ignition systems;
• Maximum power gasoline internal combustion engines achieved in a narrow rev range.