How does a gasoline internal combustion engine work?

Everything about internal combustion engines: design, principle of operation and tuning

The first internal combustion engine was the De Rivaz power unit, named after its creator Francois de Rivaz, originally from France, who designed it in 1807.

This engine already had spark ignition; it had a connecting rod, with a piston system, that is, it was a kind of prototype of modern engines.

57 years later, de Rivaz’s compatriot Etienne Lenoir invented a two-stroke unit. This unit had a horizontal arrangement of its only cylinder, had spark ignition and worked on a mixture of lighting gas and air. At that time, the work of the internal combustion engine was already sufficient for small-sized boats.

Another 3 years later, the German Nikolaus Otto became a competitor, whose brainchild was a four-stroke naturally-aspirated engine with a vertical cylinder. The efficiency in this case increased by 11%, in contrast to the efficiency of the Rivaz internal combustion engine, it became 15 percent.

A little later, in the 80s of the same century, the Russian designer Ogneslav Kostovich first launched a carburetor-type unit, and engineers from Germany Daimler and Maybach improved it into a lightweight form, which began to be installed on motorcycles and vehicles.

In 1897, Rudolf Diesel introduced the internal combustion engine using compression ignition, using oil as fuel. This type of engine became the ancestor of diesel engines that are still in use today.

Types of engines

Carburetor-type gasoline engines operate on fuel mixed with air. This mixture is pre-prepared in the carburetor and then enters the cylinder. In it, the mixture is compressed and ignited by a spark from the spark plug.
Injection engines differ in that the mixture is supplied directly from the injectors to the intake manifold. This type has two injection systems - mono-injection and distributed injection.
In a diesel engine, ignition occurs without spark plugs. The cylinder of this system contains air heated to a temperature that exceeds the ignition temperature of the fuel. Fuel is supplied to this air through a nozzle, and the entire mixture is ignited in the form of a torch.
A gas internal combustion engine has a thermal cycle principle; the fuel can be either natural gas or hydrocarbon gas. The gas enters the reducer, where its pressure is stabilized to operating pressure. Then it enters the mixer, and eventually ignites in the cylinder.
Gas-diesel internal combustion engines operate on the principle of gas engines, only unlike them, the mixture is ignited not by a spark plug, but by diesel fuel, the injection of which occurs in the same way as in a conventional diesel engine.
Rotary piston types of internal combustion engines are fundamentally different from others by the presence of a rotor that rotates in a chamber shaped like a figure eight. To understand what a rotor is, you need to understand that in this case the rotor plays the role of a piston, timing belt and crankshaft, that is, there is no special timing mechanism here at all. With one revolution, three working cycles occur at once, which is comparable to the operation of a six-cylinder engine.

Principle of operation

Currently, the four-stroke principle of operation of the internal combustion engine predominates. This is explained by the fact that the piston passes through the cylinder four times - up and down in equal amounts, two at a time.

How does an internal combustion engine work:

The first stroke - the piston draws in the fuel mixture as it moves down. In this case, the intake valve is open.
After the piston reaches the lower level, it moves upward, compressing the combustible mixture, which, in turn, takes on the volume of the combustion chamber. This stage, included in the principle of operation of the internal combustion engine, is the second in a row. The valves, at the same time, are closed, and the tighter they are, the better the compression occurs.
In the third stroke, the ignition system is turned on, since this is where the fuel mixture ignites. In the purpose of the engine’s operation, it is called “working”, since this begins the process of putting the unit into operation. The piston begins to move downward as a result of the fuel explosion. As in the second stroke, the valves are closed.
The final beat is the fourth, graduation, which makes it clear what the completion of a full cycle is. The piston discharges the exhaust gases from the cylinder through the exhaust valve. Then everything is repeated cyclically again; you can understand how an internal combustion engine works by imagining the cyclical operation of a clock.

ICE device

It is logical to consider the structure of an internal combustion engine from the piston, since it is the main element of operation. It is a kind of “glass” with an empty cavity inside.

https://www.youtube.com/watch?v=ilZyCD-QlJg

The piston has slots in which the rings are fixed. These same rings are responsible for ensuring that the flammable mixture does not escape under the piston (compression), as well as for ensuring that oil does not get into the space above the piston itself (oil scraper).

Operating procedure

When the fuel mixture enters the cylinder, the piston goes through the four strokes described above, and the reciprocating movement of the piston sets the shaft in motion.
The further order of engine operation is as follows: the upper part of the connecting rod is fixed to a pin, which is located inside the piston skirt. The crankshaft crank secures the connecting rod. The piston, when moving, rotates the crankshaft and the latter, in due time, transmits torque to the transmission system, from there to the gear system and then to the drive wheels. In the design of rear-wheel drive car engines, the driveshaft also acts as an intermediary to the wheels.

ICE design

The gas distribution mechanism (GDM) in the internal combustion engine is responsible for fuel injection, as well as for the release of gases.

The timing mechanism consists of an overhead valve and a lower valve, and can be of two types - belt or chain.

The connecting rod is most often made from steel by stamping or forging. There are types of connecting rods made of titanium. The connecting rod transmits the forces of the piston to the crankshaft.

A crankshaft made of cast iron or steel is a set of main and connecting rod journals. Inside these journals there are holes responsible for supplying oil under pressure.

The cylinder head (cylinder head) of most internal combustion engines, like the cylinder block, is most often made of cast iron and less often of various aluminum alloys. The cylinder head contains combustion chambers, intake and exhaust channels, and spark plug holes. There is a gasket between the cylinder block and the cylinder head, ensuring complete tightness of their connection.

The lubrication system, which includes an internal combustion engine, includes the oil pan, oil intake, oil pump, oil filter and oil cooler. All this is connected by canals and complex highways. The lubrication system is responsible not only for reducing friction between engine parts, but also for cooling them, as well as reducing corrosion and wear, increasing the life of the internal combustion engine.

The design of the engine, depending on its type, type, country of manufacturer, may be supplemented with something or, on the contrary, some elements may be missing due to the obsolescence of individual models, but the general design of the engine remains unchanged, as well as the standard principle of engine operation internal combustion.

Additional units

Of course, an internal combustion engine cannot exist as a separate organ without additional units that ensure its operation. The starting system spins the engine and puts it into working condition. There are different starting principles depending on the type of motor: starter, pneumatic and muscular.

The transmission allows you to develop power within a narrow rpm range. The power supply system provides the internal combustion engine with low electricity. It includes a battery and a generator that provides a constant flow of electricity and charges the battery.

The exhaust system provides the release of gases. Any car engine device includes: an exhaust manifold, which collects gases into a single pipe, a catalytic converter, which reduces the toxicity of gases by reducing nitrogen oxide and uses the resulting oxygen to burn out harmful substances.

The muffler in this system serves to reduce the noise coming from the engine. Internal combustion engines of modern cars must comply with legal standards.

Fuel type

You should also remember about the octane number of the fuel used by different types of internal combustion engines.

But there are also engines for which increasing the octane number above that set by the manufacturer will lead to premature failure. This can happen by burning out the pistons, destroying the rings, or causing soot in the combustion chambers.

The plant provides its own minimum and maximum octane number required by an internal combustion engine.

Tuning

Those who like to increase the power of internal combustion engines often install (if this is not provided by the manufacturer) various types of turbines or compressors.

The compressor produces little power at idle speed, but maintains a stable speed. The turbine, on the contrary, squeezes out maximum power when it is turned on.

The installation of certain units requires consultation with specialists who have experience in a narrow field, since repair, replacement of units, or addition of additional options to an internal combustion engine is a deviation from the purpose of the engine and reduces the life of the internal combustion engine, and incorrect actions can lead to irreversible consequences, that is, the operation of the internal combustion engine may be permanently terminated.

All about internal combustion engines: design, principle of operation and tuning Link to main publication

Source: https://dvigatels.ru/uhod/dvigatel-vnutrennego-sgoraniya.html

The structure of a modern internal combustion engine

The invention of the internal combustion engine allowed humanity to take significant steps forward in development. Now engines, which use the energy released during the combustion of fuel to perform useful work, are used in many areas of human activity. But these engines are most widespread in transport.

Principle of operation

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

If combustion takes place in a closed space, the pressure generated during combustion will put pressure on the walls of this space.

If one of the walls is made movable, then the pressure, trying to increase the volume of the enclosed space, will move this wall.

If you attach some kind of rod to this wall, then it will already perform mechanical work - moving away, it will push this rod. By connecting the rod to the crank, when moving it will force the crank to rotate relative to its axis.

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

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

There are 4 measures in total:

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

Piston engine strokes

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

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

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

Cylinder block

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

The design features of the block depend on certain conditions - the number of cylinders, their location, and cooling method. The number of cylinders that are combined in one block can vary from 1 to 16.

Moreover, blocks with an odd number of cylinders are rare; of the engines currently produced, only one- and three-cylinder units can be found.

Most units come with a pair of cylinders - 2, 4, 6, 8 and less often 12 and 16.

Four-cylinder block

Power plants with 1 to 4 cylinders usually have an in-line cylinder arrangement.

If the number of cylinders is greater, they are arranged in two rows, with a certain angle of position of one row relative to the other, the so-called power plants with a V-shaped position of the cylinders.

This arrangement made it possible to reduce the dimensions of the block, but at the same time their manufacture is more difficult than with an in-line arrangement.

Eight cylinder block

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

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

There are two types of cooling used in power plants - air and liquid. The design feature of the block depends on this. The air-cooled unit is smaller in size and structurally simpler, since the cylinders are not included in its design.

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

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

crank mechanism

The crank mechanism, which is part of the engine design, ensures the conversion of the reciprocating movement of the piston in the sleeve into rotational movement of the crankshaft. The main element of this mechanism is the crankshaft. It has a movable connection to the cylinder block. This connection ensures rotation of this shaft around its axis.

A flywheel is attached to one end of the shaft. The flywheel's job is to transmit torque from the shaft further.

Since a 4-stroke engine has only one half-turn with useful action per two revolutions of the crankshaft - the power stroke, the rest require reverse action, which is performed by the flywheel.

Having significant mass and rotating, due to its kinetic energy it ensures rotation of the knees. shaft during preparatory strokes.

Flywheel device

The flywheel circle has a toothed ring, which is used to start the power plant.

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

This mechanism also includes connecting rods, which transmit force from the piston to the crankshaft and back. The connecting rods are also attached to the shaft movably.

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

Cylinder-piston group

This group consists of cylinder liners, pistons, piston rings and pins. It is in this group that the combustion process takes place and the energy released is transferred for conversion. Combustion occurs inside the liner, which is closed on one side by the block head and on the other by the piston. The piston itself can move inside the liner.

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

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

Gas distribution mechanism

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

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

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

The 4-stroke engine has a valve timing mechanism. The fuel in such an engine is supplied through special holes in the head. These holes are closed with valves.

When it is necessary to supply fuel or remove gases from the cylinder, the corresponding valve is opened.

The opening of the valves is ensured by the camshaft, which at the right moment presses on the required valve with its cams and it opens the hole. The camshaft is driven by the crankshaft.

Timing belt and chain drive

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

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

Supply system

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

Engines using gasoline have two types of fuel systems - carburetor and injection. In the first system, mixture formation is carried out in the carburetor. It dispenses and supplies fuel to the air flow passing through it, then this mixture is supplied to the cylinders. This system consists of a fuel tank, fuel lines, a vacuum fuel pump and a carburetor.

Carburetor system

The same is done in injection cars, but their dosage is more accurate. Also, fuel in the injectors is added to the air flow already in the intake pipe through the nozzle.

This nozzle atomizes fuel, which ensures better mixture formation.

The injection system consists of a tank, a pump located in it, filters, fuel lines, and a fuel rail with injectors installed on the intake manifold.

In diesel engines, the components of the fuel mixture are supplied separately. The gas distribution mechanism supplies only air to the cylinders through the valves. Fuel is supplied to the cylinders separately, by injectors and under high pressure. This system consists of a tank, filters, a high-pressure fuel pump (HPFP) and injectors.

The difference between a diesel engine and a gasoline engine

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

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

Lubrication system

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

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

Cooling system

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

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

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

Ignition system

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

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

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

Electrical equipment

This equipment supplies the vehicle’s on-board network with electricity, including the ignition system. This equipment also starts the engine. It consists of a battery, a generator, a starter, wiring, and various sensors that monitor the operation and condition of the engine.

This is the whole structure of an internal combustion engine. Although it is constantly being improved, its operating principle does not change; only individual components and mechanisms are improved.

Modern developments

The main task that automakers are struggling with is reducing fuel consumption and emissions of harmful substances into the atmosphere. Therefore, they are constantly improving the power supply system, the result is the recent emergence of direct injection injection systems.

Alternative types of fuel are being sought; the latest development in this direction so far is the use of alcohols and vegetable oils as fuel.

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

Source: http://autoleek.ru/dvigatel/dvs/ustrojstvo-dvs.html

Types of internal combustion engines: what internal combustion engines exist

A piston internal combustion engine (internal combustion engine) is a heat engine and operates on the principle of burning a mixture of fuel and air in a combustion chamber. The main task of such a device is to convert the combustion energy of a fuel charge into useful mechanical work.

Despite the general principle of operation, today there are a large number of units that differ significantly from each other due to a number of individual design features. In this article we will talk about what types of internal combustion engines there are, as well as what their main features and differences are.

Types of internal combustion engines

Let's start with the fact that the internal combustion engine can be two-stroke and four-stroke. As for car engines, these units are four-stroke. The engine operating cycles are:

intake of the fuel-air mixture or air (which depends on the type of internal combustion engine);
compression of the mixture of fuel and air;
fuel charge combustion and working stroke;
release of exhaust gases from the combustion chamber;

Both gasoline and diesel piston engines operate on this principle, which are widely used in cars and other equipment. It is also worth mentioning gas units, in which gas fuel is burned in the same way as diesel fuel or gasoline.

Gasoline power units

As for piston gasoline engines, such engines have an ignition system to ignite the working mixture from a spark. The power systems in such units can be carburetor or injection (injection).

The preparation of the working mixture in carburetor internal combustion engines occurs in the carburetor, then the mixed gasoline and air are supplied to the intake manifold. Today, such systems are considered obsolete, as they are not able to provide the engine with the proper environmental friendliness and efficiency.

Injection internal combustion engines, according to the type of power system design, can be mono-injection (mono-injection) or systems with distributed injection. In the first case, the circuit assumes the presence of only one injector, which injects fuel into the intake manifold. Port injection solutions have a separate injector for each cylinder, which is mounted next to the intake valves.

Such a power system, especially distributed injection, allows you to increase engine power, while achieving fuel efficiency and reducing exhaust gas toxicity. This became possible thanks to the precise dosage of the supplied fuel under the control of the ECM (electronic engine management system).

Further development of fuel supply systems led to the emergence of engines with direct injection. Their main difference from their predecessors is that air and fuel are supplied to the combustion chamber separately. In other words, the injector is not installed above the intake valves, but is mounted directly into the cylinder.

This solution allows fuel to be supplied directly, and the supply itself is divided into several stages (sub-injections). As a result, it is possible to achieve the most efficient and complete combustion of the fuel charge, the engine is able to operate on a lean mixture (for example, engines of the GDI family), fuel consumption decreases, exhaust toxicity decreases, etc.

Diesel engines

A diesel engine runs on diesel fuel and is also significantly different from a gasoline engine. The main difference is the absence of a spark ignition system. Ignition of the mixture of fuel and air in a diesel engine occurs due to compression.

Simply put, air is first compressed in the cylinders, which becomes very hot. At the last moment, diesel fuel is injected directly into the combustion chamber, after which the heated and highly compressed mixture ignites on its own.

If we compare diesel and gasoline internal combustion engines, diesel is characterized by higher efficiency, better efficiency and maximum torque, which is available at low speeds.

Taking into account the fact that diesel engines develop more thrust at lower crankshaft speeds, in practice such an engine does not need to be “twisted” at the start, and you can also count on confident pickup from the very bottom.

However, the list of disadvantages of such units includes a sensitive fuel system, as well as greater weight and lower speeds at maximum speed. The fact is that diesel is initially “low-speed” and has a lower crankshaft speed compared to gasoline internal combustion engines.

Diesels also have a larger mass, since the characteristics of compression ignition imply more severe loads on all elements of such a unit. In other words, the parts in a diesel engine are stronger and heavier. Diesel engines are also noisier, which is due to the process of ignition and combustion of diesel fuel.

Rotary engine

The Wankel engine (rotary piston engine) is a fundamentally different power plant. In such an internal combustion engine, the usual pistons that perform reciprocating movements in the cylinder are simply absent. The main element of a rotary motor is the rotor.

The specified rotor rotates along a given path. Rotary internal combustion engines are gasoline, since such a design is not capable of providing a high degree of compression of the working mixture.

The advantages include compactness, high power with a small displacement, as well as the ability to quickly spin up to high speeds. As a result, cars with such an internal combustion engine have outstanding acceleration characteristics.

If we talk about the minuses, then it is worth highlighting a noticeably reduced resource compared to piston units, as well as high fuel consumption.

Also, the rotary engine is characterized by increased toxicity, that is, it does not quite fit into modern environmental standards.

Hybrid engine

A hybrid power unit is actually a combination of a piston gasoline or diesel internal combustion engine and an electric motor. The design also includes a traction battery that powers the electric motor.

The hybrid operates on the principle of maximum fuel economy, that is, the internal combustion engine is used only in certain modes. During quiet driving, the electric motor rotates the wheels, and the internal combustion engine is switched on when the battery is discharged, intense acceleration of the vehicle is required, the loads are quite high, etc.

Also, during operation of the hybrid installation, an energy recovery scheme is actively used. For example, during engine braking, the generator runs, which recharges the traction battery.

This combination of two types of power plants allows for improved acceleration dynamics (especially when the internal combustion engine and electric motor are simultaneously used), significant fuel savings and low toxic exhaust emissions are observed.

ICE layout and technical characteristics

It is also worth adding that there are numerous types of internal combustion engines, which differ from each other in the layout and arrangement of the cylinders.

The fact is that the space in the engine compartment is limited, and on different cars it becomes necessary to fit a unit with a certain number of cylinders in such a space.

As a rule, in terms of layout on most machines you can most often find:

in-line engine;
V-shaped engine;
boxer engine;

An in-line engine means that all its cylinders are located in the same plane. In-line “fours” (4-cylinder engine) are the most common type of internal combustion engine. In-line sixes are also very popular, they vibrate less and have acceptable power, but such an engine turns out to be quite long.

Another option is a V-twin engine. The cylinders in such a motor are located in two planes, resembling the letter “V”. Such an internal combustion engine has 6 or 8 cylinders (V6 or V8), while the length of the engine is shorter compared to an in-line engine, although the width naturally increases. Let us also add that the angle between the planes is usually called the camber angle.

The boxer engine also deserves special attention. It is noteworthy that this arrangement assumes a camber angle of 180 degrees. In fact, the cylinders and pistons are located opposite each other, and the unit itself is called a “boxer”. This arrangement made it possible to reduce the height of the boxer, reduce the level of vibrations, improve weight distribution, etc.

Let us add that there are so-called VR type engines. Their feature is a small camber angle, making it possible to reduce the size of the internal combustion engine in length and width. Also worth mentioning are the powerful W-motors.

The specified power units are multi-cylinder (for example, W12). As for the layout, the design may include three rows of cylinders at once, which are located at a large camber angle.

We also recommend reading the article about what a boxer engine is. From this article you will learn about the design features, as well as the main advantages and disadvantages of motors of this type.

Another option is the arrangement of the same three rows of cylinders, while the camber angle is reduced as much as possible (as is the case with the VR layout). As a rule, it is the latter option that has taken root on powerful premium passenger cars, sports cars and respectable SUVs.

The fact is that even with such a number of cylinders, the engine is still compact.

Main technical parameters of the internal combustion engine

Internal combustion engines also have a number of characteristics and parameters that are laid down structurally. Simply put, we are talking about displacement, compression ratio, power and torque, etc.

Of greatest interest to the average person, of course, is the power and torque characteristics. The torque that is created on the crankshaft actually indicates how much traction force will be transmitted to the wheels.

Naturally, the greater the torque, the greater the traction. In other words, the acceleration dynamics depend on this indicator.

As for engine power, this is a value that reflects the work done per unit of time.

Increasing torque and power is possible in two ways:

larger working volume;
burning more fuel-air mixture;

To put it simply, in the first case we are talking about a physical increase in the combustion chamber and cylinder volume. The second involves forced air supply into the cylinders under pressure to burn more fuel.

As a rule, powerful engines with a large volume are naturally aspirated, that is, they “suck” outside air into the cylinders independently due to the resulting vacuum from the movement of the pistons. Powerful units, while having a smaller volume, are equipped with mechanical compressors or turbocharging. In such internal combustion engines, air is forced, that is, it enters the combustion chamber under pressure.

What's the result?

As you can see, the above material gives a general idea of what internal combustion engines are. Moreover, even taking into account the general principle of operation, power units can differ significantly in such indicators as layout, power, torque, fuel consumption, etc.

We also recommend reading the article about what a GDI engine is. From this article you will learn about the design features, operating principles, as well as the pros and cons of motors of this type.

Moreover, even engines that are similar in design (for example, an inline four-cylinder engine) may have a different number of intake and exhaust valves per cylinder (for example, 8 and 16 valve engines).

Some internal combustion engines use a variable valve timing system in combination with turbocharging to obtain the required power, while others with exactly the same displacement and layout do not have such solutions.

For this reason, to objectively assess the performance of a particular engine at different speeds, not at the crankshaft, but at the wheels, it is necessary to carry out special comprehensive measurements on a dynamometer stand.

Source: http://KrutiMotor.ru/kakie-byvayut-dvigateli-vnutrennego-sgoraniya/

Operating principle of an internal combustion engine

The liquid fuel internal combustion engine, developed and first put into practice in the second half of the 19th century, was the second example in history, after the steam engine, 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 an internal combustion engine plays a decisive role in the global logistics system, which is becoming increasingly 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 cars, 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 primarily in aviation. The most numerous, familiar and significant is the third group of vehicles, which use internal combustion engines.

This is the largest group in terms of quantity, diversity, and influence on human economic life. The principle of operation of an internal combustion engine is the same for any vehicle equipped with such an engine.

What is it?

Physics of the process

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

As generally as possible, we can say that to perform useful work, the energy of the molecular bonds of liquid fuel burned during engine operation is used.

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

high potential energy of molecular bonds used as fuel for a mixture of light hydrocarbons “for example, gasoline”
quite simple and safe, in comparison, for example, with atomic energy, the method of its release
relative abundance of light hydrocarbons on our planet
the natural state of aggregation of such fuel, allowing it to be conveniently stored and transported.

Another important factor is that the oxidizing agent necessary for the process of energy release is oxygen, of which the atmosphere consists of more than 20 percent. 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.

, to burn a kilogram of fuel, almost 15 kg of oxygen is needed. However, such a process, called stoichiometric, is not feasible in practice.

In reality, there is always some part of the fuel that does not combine with oxygen during the reaction.

Moreover, for certain operating modes of internal combustion engines, stoichiometry is even harmful.

Now that the chemical process is generally understood, 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 according to the so-called Otto cycle.

The most famous and, as they say, classic work cycle is the engine operation process, patented back in 1876 by Nikolaus Otto, consisting of four parts. “cycles, hence the four-stroke internal combustion engines.”

The first stroke is the creation of a vacuum in the cylinder by the piston 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, which continues to move, compresses the mixture - we get the second stroke.

On the third stroke, the mixture ignites “Otto used a conventional burner, now the spark plug is responsible for this.”

Ignition of the mixture creates the release of a large amount of gas, which puts pressure on the piston and forces it to rise - to do 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, but in the first cars the crankshaft had to be turned manually “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 internal combustion engines. At first, this was due to the effect of the patent, which many wanted to circumvent.

As a result, already at the beginning of the last century, the Atkinson cycle was created, which changed the engine design in such a way that all piston movements were performed in one revolution of the crankshaft.

This increased the efficiency of the engine, but reduced its power. In addition, an engine operating on this cycle does not require a separate camshaft and gearbox.

However, this engine did not become widespread due to a decrease in the power of the unit and a rather complex design.

Source: http://RuliKolesa.ru/printsip-raboty-dvs/