Most drivers have no idea what a car engine is. And you need to know this, because it’s not in vain that when studying in many driving schools, students are told the principle ICE operation. 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 from each other in small things (fuel injection systems, cylinder arrangement, etc.). However, the basic principle for all types of internal combustion engines 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 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 throws the piston down with great force, 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 a typical diagram of a car engine (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 crankshaft and transforms linear motion (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 old VAZ car engines and even engines of European manufacturers have worn rings that do not create an effective seal between the piston and cylinder, which can cause oil to enter the combustion chamber. In such a situation, there will be increased consumption gasoline and "zhor" oil.

These are the basic design elements that take place in all engines. internal combustion. 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. At this time, the exhaust valve opens, the exhaust mixture in the form of gas exits the combustion chamber and through exhaust system hits the street. 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 vehicles 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.

Reading 10 min. Views 1k. Posted on November 17, 2018

Almost all modern cars are equipped with internal combustion engine having the abbreviation DVS. Despite constant progress and today's desire automobile concerns to abandon motors running on petroleum products in favor of more environmentally friendly electricity, the lion's share of cars runs on gasoline or diesel fuel.

Main ICE principle is that the fuel mixture ignites directly inside the unit, and not outside it (as, for example, in diesel locomotives or obsolete steam locomotives). This method has a relatively high efficiency. In addition, if we talk about alternative electric motors, internal combustion engines have a number of undeniable advantages.

• large power reserve on one tank;
• fast refueling;
• according to forecasts, in a few years the energy systems of developed countries will not be able to meet the demand for electricity due to the large number of electric cars, which can lead to collapse.

Classification of internal combustion engines

Directly ICE differ in their device. All motors can be divided into several of the most popular categories depending on the principle of operation:

Petrol

The most common category. Works on the main products of oil refining. The main element in such a motor is a cylinder-piston group or CPG, which includes: crankshaft, connecting rod, piston, piston rings and a complex gas distribution mechanism that ensures timely filling and purging of the cylinder.

Gasoline internal combustion engines are divided into two types depending on the power system:

1. carburetor. An outdated model in the conditions of modern reality. Here, the formation of the fuel-air mixture is carried out in the carburetor, and the proportion of air and gasoline is determined by a set of jets. After that, the carburetor feeds fuel assemblies into the combustion chamber. The disadvantages of this power supply principle are increased fuel consumption and whimsicality of the entire system. In addition, it is highly dependent on weather, temperature and other conditions.
2. injector or injection. The principles of operation of an engine with an injector are radically opposite. Here, the mixture is injected directly into the intake manifold through injectors and then diluted with the right amount of air. The electronic control unit is responsible for the correct operation, which independently calculates the desired proportions.

Diesel

The design of a diesel engine is fundamentally different from a gasoline unit. The ignition of the mixture here is not due to the spark plugs, which give a spark at a certain moment, but due to the high degree of compression in the combustion chamber. This technology has its advantages (greater efficiency, less power loss due to high altitude, high torque) and disadvantages (high-pressure fuel pump's capriciousness to fuel quality, large CO2 and soot emissions).

Wankel rotary piston engines

This unit has a piston in the form of a rotor and three combustion chambers, each of which is connected to a spark plug. Theoretically, a rotor moving along a planetary trajectory, each stroke makes a working stroke. This allows you to significantly increase the efficiency and increase the power of the internal combustion engine. In practice, this affects a much smaller resource. To date, only car company Mazda makes such units.

gas turbine

The principle of operation of this type of internal combustion engine is that thermal energy is converted into mechanical energy, and the process itself ensures the rotation of the rotor, which drives the turbine shaft. Similar technologies are used in aviation construction.

Any piston internal combustion engine (the most common in modern realities) has a mandatory set of parts. These parts include:

1. Cylinder block, inside which the pistons move and the process itself takes place;
2. CPG: cylinder, pistons, piston rings;
3. crank mechanism. It includes the crankshaft, connecting rod, "fingers" and retaining rings;
4. timing. Mechanism with valves, camshafts or "petals" (for 2-stroke engines), which ensures the correct supply of fuel at the right time;
5. intake systems. They were mentioned above - it includes carburetors, air filters, injectors, fuel pump, injectors;
6. Exhaust systems. Removes exhaust gases from the combustion chamber, and also reduces exhaust noise;

The principle of operation of the internal combustion engine

Depending on their device, engines can be divided into four-stroke and two-stroke. A stroke is the movement of the piston from its lower position (BDC dead center) to its upper position (TDC dead center). In one cycle, the engine manages to fill the combustion chambers with fuel, compress and ignite it, and also clean them. Modern internal combustion engines do this in two or four cycles.

The principle of operation of a two-stroke internal combustion engine

A feature of such a motor was that the entire operating cycle occurs in just two piston movements. When moving up, a rarefied pressure is created, which sucks the fuel mixture into the combustion chamber. Near TDC, the piston closes the intake port and the spark plug ignites the fuel. The second stroke is followed by a working stroke and purge. The exhaust channel opens after passing part of the way down and allows the exit of exhaust gases. After that, the process is restarted on a new one.

Theoretically, the advantage of such a motor is a higher power density. This is logical, because the combustion of fuel and the working cycle occurs twice as often. Accordingly, the power of such an engine can be twice as much. But this design has a lot of problems. Due to large blowdown losses, high fuel consumption, as well as complexities in the calculations and "scrambled" operation of the engine, this technology is currently used only on small-capacity vehicles.

Interestingly, half a century ago, the development of a diesel two-stroke internal combustion engine was actively carried out. The process of work practically did not differ from the gasoline counterpart. However, despite the advantages of such a motor, it was abandoned due to a number of shortcomings.

The main disadvantage was the huge overspending of oil. Due to the combined lubrication system, fuel entered the combustion chamber along with oil, which then simply burned out or was removed through the exhaust system. Large thermal loads also required a more bulky cooling system, which increased the size of the motor. The third disadvantage was high flow air that led to premature wear air filters.

Four-stroke internal combustion engine

A motor where the duty cycle takes four strokes of the piston is called a four-stroke engine.

1. First stroke - inlet. The piston moves from top dead center. At this moment, the timing opens the intake valve, through which the fuel-air mixture enters the combustion chamber. In the case of carburetor units, intake can be carried out due to vacuum, and injection engines inject fuel under pressure.
2. Second step - compression. The piston then moves up from bottom dead center. At this point, the intake valve is closed, and the mixture is gradually compressed in the cavity of the combustion chamber. Working temperature rises to 400 degrees.
3. Third stroke - stroke of the piston. At TDC, the spark plug (or high compression ratio in the case of a diesel) ignites the fuel and pushes the piston and crankshaft down. This is the main cycle in the entire cycle of the engine.
4. Fourth measure - release. The piston moves up again, the exhaust valve opens, and exhaust gases are removed from the combustion chamber.

Additional ICE systems

Regardless of what the engine consists of, it must have auxiliary systems that can ensure its proper operation. For example, valves must open at the right time, the right amount of fuel must enter the chambers in a certain proportion, a spark must be supplied at the right time, etc. Below are the main parts that contribute to correct operation.

Ignition system

This system is responsible for the electrical part on fuel ignition. The main elements include:

• Battery. The main power source is the battery. It provides rotation of the starter with the engine off. After that, the generator turns on, which feeds the engine, and also recharges the battery itself. battery through the charging relay.
• Ignition coil. A device that transfers a momentary charge directly to a spark plug. In modern cars, the number of coils is equivalent to the number of cylinders that work in the engine.
• Ignition switch or distributor. Special "smart" electronic device, which determines the moment of spark supply.
• Spark plug. An important element in a gasoline internal combustion engine, which ensures the timely ignition of the fuel-air mixture. Advanced engines have two spark plugs per cylinder.

intake system

The mixture must enter the combustion chambers on time. The intake system is responsible for this process. It includes:

• air intake. A branch pipe specially brought out to a place inaccessible to water, dust or dirt. Air is taken through it, which then enters the engine;
• Air filter. A replacement part that cleans the air of dirt and prevents foreign materials from entering the combustion chamber. As a rule, modern cars have replaceable filters made of thick paper or oiled foam rubber. On more archaic engines, oil air filters are found.
• Throttle. A special damper that regulates the amount of air entering the intake manifold. On modern technology operates through electronics. First, the driver presses the gas pedal, and then the electronic system processes the signal and follows the command.
• Intake manifold . Pipe that distributes fuel-air mixture on different cylinders. Auxiliary elements in this system are intake flaps and amplifiers.

Fuel systems

The principle of operation of any internal combustion engine implies the timely supply of fuel and its uninterrupted supply. The complex also includes several basic elements:

• Fuel tank. The tank where the fuel is stored. Typically located at the maximum safe place, away from the motor and made of non-combustible material (impact-resistant plastic). In the lower part of it, a gasoline pump is installed, which takes fuel.
• fuel line. Hose system leading from fuel tank directly tointernal combustion engine.
• Mixer. A device where fuel and air are mixed. This point has already been mentioned above - a carburetor or an injector may be responsible for this function. The main requirement is synchronous and timely submission.
• Head device in injection engines, which determines the quality, quantity and proportions of the mixture formation.

Exhaust system

During the operation of an internal combustion engine, exhaust gases are generated that must be removed from the engine. For proper operation, this system must have the following elements:

• Exhaust manifold. Refractory metal device with high temperature resistance. It is in it that the exhaust gases from engine .
• downpipe or pants. Transport part exhaust gases further down the path.
• Resonator. A device that reduces the speed of movement of exhaust gases and the repayment of their temperature.
• Catalyst. Object for purification of gases from CO2 or soot particles. Here is the lambda probe.
• Muffler. "Bank", having a number internal elements designed to repeatedly change the direction of exhaust gases. This leads to a reduction in their noise.

Lubrication system

The operation of an internal combustion engine will be very short if the parts are not provided with lubrication. All equipment uses a special high-temperature oil, which has its own viscosity characteristics depending on the operating modes of the motor. In addition, the oil prevents overheating, ensures the removal of carbon deposits and the appearance of corrosion.

The following elements are intended to maintain the health of the system:

• Oil pan. This is where the oil is poured. This is the main storage tank. You can control the level with a special probe.
• Oil pump. Located near the bottom of the pallet. Provides fluid circulation throughout the motor through special channels and its return back to the crankcase.
• Oil filter . Guarantees the purification of the liquid from dust, metal chips and other abrasive substances that enter the oil.
• Radiator. Provides effective cooling to the required temperatures.

Cooling system

Another element that is necessary for powerful engines internal combustion. It provides cooling of parts and eliminates the possibility of overheating. Consists of the following parts:

• Radiator. A special element having a "honeycomb" structure. It is an excellent heat exchanger and effectively transfers heat, guaranteeing cooling of antifreeze.
• Fan. An additional element blowing on the radiator. It turns on when the natural flow of incoming air can no longer provide effective heat dissipation.
• water pump. A pump that helps the liquid circulate through the large or small circle of the system (depending on the situation).
• Thermostat. A valve that opens the damper, letting fluid through the desired circle. Works in conjunction with an engine and coolant temperature sensor.

Conclusion

The first internal combustion engine appeared a very long time ago - almost a century and a half ago. Since then, a huge number of different innovations or interesting technical solutions have been made, which sometimes changed the look of the motor beyond recognition. But the general principle of operation of the internal combustion engine remained the same. And even now, in the era of the fight for the environment and the ever-tightening standards for CO2 emissions, electric vehicles are still unable to seriously compete with internal combustion engines. Gasoline cars are still more alive than all living things, and we live in the golden era of the automotive industry.

Well, for those who are ready to dive into the topic even deeper, we have a great video:

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

How a car engine works - we study the device diagram

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

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

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

How a car engine works - briefly about complex processes

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

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

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

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

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

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

Many models use the V-engine design. With this option, the cylinders are located at an angle to each other (within 180 degrees). In many designs, the number of cylinders ranges from 6 to 12 or more. This allows you to significantly reduce the linear size of the engine and reduce its length.

However, lighting gas was suitable not only for lighting.

The credit for creating a commercially successful internal combustion engine belongs to the Belgian mechanic Jean Étienne Lenoir. While working at an electroplating plant, Lenoir came up with the idea that the air-fuel mixture in a gas engine could be ignited with an electric spark, and decided to build an engine based on this idea. Having solved the problems that arose along the way (tight stroke and overheating of the piston, leading to jamming), having thought through the engine cooling and lubrication system, Lenoir created a workable internal combustion engine. In 1864, more than three hundred of these engines were produced. different power. Having grown rich, Lenoir stopped working on further improvement of his car, and this predetermined her fate - she was forced out of the market by a more advanced engine created by the German inventor August Otto and received a patent for the invention of his model. gas engine in 1864.

In 1864, the German inventor Augusto Otto entered into an agreement with the wealthy engineer Langen to implement his invention - the company "Otto and Company" was created. Neither Otto nor Langen had sufficient knowledge of electrical engineering and abandoned electric ignition. They ignited with an open flame through a tube. The cylinder of the Otto engine, unlike the Lenoir engine, was vertical. The rotating shaft was placed above the cylinder on the side. Principle of operation: a rotating shaft raised the piston by 1/10 of the height of the cylinder, as a result of which a rarefied space formed under the piston and a mixture of air and gas was sucked in. The mixture then ignited. During the explosion, the pressure under the piston increased to approximately 4 atm. Under the action of this pressure, the piston rose, the volume of gas increased and the pressure fell. The piston, first under gas pressure, and then by inertia, rose until a vacuum was created under it. Thus, the energy of the burnt fuel was used in the engine with maximum completeness. This was Otto's main original find. The downward working stroke of the piston began under the action of atmospheric pressure, and after the pressure in the cylinder reached atmospheric pressure, the exhaust valve opened, and the piston displaced the exhaust gases with its mass. Due to the more complete expansion of the combustion products, the efficiency of this engine was significantly higher than Engine efficiency Lenoir and reached 15%, that is, it exceeded the efficiency of the best steam engines that time. In addition, Otto's engines were almost five times more economical than engines Lenoir, they immediately began to be in great demand. In subsequent years, about five thousand of them were produced. Despite this, Otto worked hard to improve their design. Soon, a crank gear was used. However, the most significant of his inventions was made in 1877, when Otto received a patent for new engine with a four stroke cycle. This cycle still underlies the operation of most gas and gasoline engines to this day.

Types of internal combustion engines

piston engine

rotary internal combustion engine

Gas turbine internal combustion engine

• Reciprocating engines - the combustion chamber is contained in a cylinder, where the thermal energy of the fuel is converted into mechanical energy, which is converted from the piston's forward motion into rotational motion using a crank mechanism.

ICEs are classified:

a) By purpose - are divided into transport, stationary and special.

b) By the type of fuel used - light liquid (gasoline, gas), heavy liquid ( diesel fuel, marine fuel oils).

c) According to the method of formation of a combustible mixture - external (carburetor, injector) and internal (in the engine cylinder).

d) According to the method of ignition (with forced ignition, with compression ignition, calorising).

e) According to the location of the cylinders, they are divided into in-line, vertical, opposed with one and two crankshafts, V-shaped with an upper and lower crankshaft, VR-shaped and W-shaped, single-row and double-row star-shaped, H-shaped, double-row with parallel crankshafts, "double fan", diamond-shaped, three-beam and some others.

Petrol

Petrol carburetor

The working cycle of four-stroke internal combustion engines takes two complete revolutions of the crank, consisting of four separate strokes:

1. intake,
2. charge compression,
3. working stroke and
4. release (exhaust).

The change in working cycles is provided by a special gas distribution mechanism, most often it is represented by one or two camshafts, a system of pushers and valves that directly provide a phase change. Some internal combustion engines have used spool sleeves (Ricardo) for this purpose, having inlet and/or exhaust ports. The communication of the cylinder cavity with the collectors in this case was ensured by the radial and rotational movements of the spool sleeve, opening the desired channel with windows. Due to the peculiarities of gas dynamics - the inertia of gases, the time of occurrence of the gas wind, the intake, power stroke and exhaust strokes in a real four-stroke cycle overlap, this is called valve timing overlap. The higher the operating speed of the engine, the greater the phase overlap and the larger it is, the lower the torque of the internal combustion engine by low revs. Therefore, modern internal combustion engines are increasingly using devices that allow you to change the valve timing during operation. Particularly suitable for this purpose are engines with solenoid valve control (BMW, Mazda). Variable compression ratio (SAAB) engines are also available for greater flexibility.

Two stroke engines have many layout options and a wide variety structural systems. The basic principle of any two-stroke engine is the performance by the piston of the functions of a gas distribution element. The working cycle consists, strictly speaking, of three cycles: the working stroke, lasting from the top dead center ( TDC) up to 20-30 degrees to the bottom dead center ( NMT), purge, which actually combines intake and exhaust, and compression, lasting from 20-30 degrees after BDC to TDC. Purging, from the point of view of gas dynamics, is the weak link of the two-stroke cycle. On the one hand, it is impossible to ensure complete separation of the fresh charge and exhaust gases, so either the loss of the fresh mixture is inevitable, literally flying out into the exhaust pipe(if the internal combustion engine is diesel, we are talking about air loss), on the other hand, the power stroke does not last half a turn, but less, which in itself reduces efficiency. At the same time, the duration of the extremely important process of gas exchange, which in a four-stroke engine takes half the working cycle, cannot be increased. Two-stroke engines may not have a gas distribution system at all. However, if we are not talking about simplified cheap engines, a two-stroke engine is more complicated and expensive due to the obligatory use of a blower or a pressurization system, the increased heat stress of the CPG requires more expensive materials for pistons, rings, cylinder liners. The performance by the piston of the functions of the gas distribution element obliges to have its height not less than the piston stroke + the height of the purge windows, which is not critical in a moped, but significantly makes the piston heavier even at relatively low powers. When the power is measured in hundreds of horsepower, the increase in piston mass becomes a very serious factor. The introduction of vertically stroked distributor sleeves in Ricardo engines was an attempt to make it possible to reduce the size and weight of the piston. The system turned out to be complicated and expensive in execution, except for aviation, such engines were not used anywhere else. Exhaust valves (with direct-flow valve scavenging) have twice the heat density compared to four-stroke exhaust valves and worse heat dissipation conditions, and their seats have longer direct contact with the exhaust gases.

The simplest in terms of the order of operation and the most complex in terms of design is the Fairbanks-Morse system, presented in the USSR and Russia, mainly by diesel diesel engines of the D100 series. Such an engine is a symmetrical two-shaft system with diverging pistons, each of which is connected to its own crankshaft. Thus, this engine has two crankshafts mechanically synchronized; the one connected to the exhaust pistons is ahead of the intake by 20-30 degrees. Due to this advance, the quality of the scavenging is improved, which in this case is direct-flow, and the filling of the cylinder is improved, since the exhaust windows are already closed at the end of the scavenging. In the 30s - 40s of the twentieth century, schemes with pairs of diverging pistons were proposed - diamond-shaped, triangular; There were aviation diesel engines with three radially diverging pistons, of which two were inlet and one exhaust. In the 1920s, Junkers proposed a single-shaft system with long connecting rods connected to the fingers of the upper pistons with special rocker arms; the upper piston transmitted forces to the crankshaft by a pair of long connecting rods, and there were three crankshafts per cylinder. There were also square pistons of the scavenging cavities on the rocker arms. Two-stroke engines with divergent pistons of any system basically have two disadvantages: firstly, they are very complex and bulky, and secondly, the exhaust pistons and liners in the area of ​​the exhaust windows have significant thermal tension and a tendency to overheat. Exhaust piston rings are also thermally stressed, prone to coking and loss of elasticity. These features make the design of such engines a non-trivial task.

Direct-flow valve-scavenged engines are equipped with a camshaft and exhaust valves. This significantly reduces the requirements for materials and execution of the CPG. The intake is carried out through the windows in the cylinder liner, opened by the piston. This is how most modern two-stroke diesels are assembled. The window area and the sleeve in the lower part are in many cases cooled by charge air.

In cases where one of the main requirements for the engine is to reduce its cost, are used different types crank-chamber contour window-window purge - loop, reciprocating-loop (deflector) in various modifications. To improve the parameters of the engine, a variety of design techniques are used - a variable length of the intake and exhaust channels, the number and location of bypass channels can vary, spools, rotating gas cutters, sleeves and curtains are used that change the height of the windows (and, accordingly, the moments of the start of intake and exhaust). Most of these engines are air-cooled passively. Their shortcomings are relatively low quality gas exchange and loss of the combustible mixture during purge, in the presence of several cylinders, the sections of the crank chambers have to be separated and sealed, the design of the crankshaft becomes more complicated and more expensive.

Additional units required for internal combustion engines

The disadvantage of an internal combustion engine is that it develops its highest power only in a narrow rev range. Therefore, an essential attribute of an internal combustion engine is a transmission. Only in some cases (for example, in airplanes) can a complex transmission be dispensed with. The idea of ​​​​a hybrid car is gradually conquering the world, in which the engine always works in the optimal mode.

In addition, an internal combustion engine needs a power system (for supplying fuel and air - preparing a fuel-air mixture), an exhaust system (for exhaust gases), and a lubrication system (designed to reduce friction forces in engine mechanisms, protect parts engine from corrosion, as well as together with the cooling system to maintain optimal thermal conditions), cooling systems (to maintain optimal thermal conditions of the engine), starting system (starting methods are used: electric starter, with the help of an auxiliary starting engine, pneumatic, with the help of human muscle power ), ignition system (for igniting the air-fuel mixture, used in positive ignition engines).

see also

• Philippe Lebon - French engineer who received a patent in 1801 for an internal combustion engine that compresses a mixture of gas and air.
• Rotary engine: designs and classification
• Rotary piston engine (Wankel engine)

Notes

Links

• Ben Knight "Increasing mileage" //Article on technologies that reduce fuel consumption of automotive internal combustion engines

The internal combustion engine (ICE) is the most common type of engine currently installed in cars. Despite the fact that a modern internal combustion engine consists of thousands of parts, the principle of its operation is quite simple. In this article, we will consider the device and the principle of operation of the internal combustion engine.

At the bottom of the page, watch the video, which clearly shows the device and the principle of operation of a gasoline internal combustion engine.

Every internal combustion engine has a cylinder and a piston. It is inside the internal combustion engine cylinder that the thermal energy released during fuel combustion is converted into mechanical energy that can make our car move. This process is repeated at a frequency of several hundred times per minute, which ensures continuous rotation of the crankshaft leaving the engine.

The principle of operation of a four-stroke internal combustion engine

The vast majority cars install four-stroke internal combustion engines, so we take it as a basis. To better understand the principle of a gasoline internal combustion engine, we invite you to take a look at the figure:

The fuel-air mixture, entering the combustion chamber through the intake valve (stroke one - intake), is compressed (stroke two - compression) and ignited by a spark plug. When fuel is burned, under the influence of high temperature, excess pressure is formed in the engine cylinder, forcing the piston to move down to the so-called bottom dead center (BDC), while making the third cycle - the working stroke. Moving down during the working stroke, with the help of a connecting rod, the piston rotates the crankshaft. Then, moving from BDC to top dead center (TDC), the piston pushes the exhaust gases through the exhaust valve into the vehicle's exhaust system - this is the fourth stroke (exhaust) of the internal combustion engine.

Tact is the process that occurs in the engine cylinder in one stroke of the piston. A set of cycles that repeat in strict sequence and with a certain frequency is usually called a work cycle, in this case, an internal combustion engine.

1. Step one - INLET. The piston moves from TDC to BDC, when this occurs, a vacuum occurs and the cavity of the internal combustion engine cylinder is filled combustible mixture through the open intake valve. The mixture, getting into the combustion chamber, mixes with the remnants of the exhaust gases. At the end of the inlet, the pressure in the cylinder is 0.07-0.095 MPa, and the temperature is 80-120 ºС.
2. Step two - COMPRESSION. The piston moves to TDC, both valves are closed, the working mixture in the cylinder is compressed, and compression is accompanied by an increase in pressure (1.2–1.7 MPa) and temperature (300–400 ºС).
3. Step three - EXTENSION. When the working mixture is ignited in the internal combustion engine cylinder, a significant amount of heat is released, the temperature rises sharply (up to 2500 degrees Celsius). Under pressure, the piston moves to BDC. The pressure is 4–6 MPa.
4. Step four - RELEASE. The piston tends to TDC through the open exhaust valve, the exhaust gases are pushed into the exhaust pipe, and then into the environment. Pressure at the end of the cycle: 0.1-0.12 MPa, temperature 600-900 ºС.

And so, you were able to make sure that the internal combustion engine is not very complicated. As they say, everything ingenious is simple. And for greater clarity, we recommend watching the video, which also shows the principle of operation of the internal combustion engine very well.