Tobacco tar effect on the human body. The harmful effects of smoking on the human body. The effect of tobacco tar on the human body

However, illuminating gas was suitable not only for lighting.

The honor of creating a commercially successful internal combustion engine belongs to the Belgian mechanic Jean Etienne Lenoir. While working at a galvanizing plant, Lenoir came up with the idea that the air-fuel mixture in a gas engine could be ignited using an electric spark, and decided to build an engine based on this idea. Having solved the problems that arose along the way (stiff running and overheating of the piston, leading to jamming) and thought through the cooling and lubrication system of the engine, Lenoir created a functional internal combustion engine. In 1864, more than three hundred of these engines of varying power were produced. Having become rich, Lenoir stopped working on further improving his machine, and this predetermined its fate - it 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 of a 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 Otto and Company company was created. Neither Otto nor Langen had sufficient knowledge of electrical engineering and abandoned electric ignition. They carried out the ignition open flame through the tube. The cylinder of the Otto engine, unlike the Lenoir engine, was vertical. The rotating shaft was placed above the cylinder on the side. Operating principle: the rotating shaft raised the piston to 1/10 of the height of the cylinder, as a result of which a rarefied space was 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 influence of this pressure, the piston rose, the volume of gas increased and the pressure dropped. The piston, first under gas pressure, and then by inertia, rose until a vacuum was created under it. Thus, the energy of the burned fuel was used in the engine to the maximum extent possible. This was Otto's main original discovery. The downward stroke of the piston began under the action atmospheric pressure, and after the pressure in the cylinder reached atmospheric, the exhaust valve opened, and the piston with its mass displaced the exhaust gases. Due to the more complete expansion of combustion products, the efficiency of this engine was significantly higher than the efficiency of the Lenoir engine and reached 15%, that is, it exceeded the efficiency of the best steam engines of that time. In addition, Otto engines were almost five times more economical than Lenoir engines; they immediately began to be used 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 transmission was used. However, his most significant invention came in 1877, when Otto received a patent for a new four-stroke cycle engine. This cycle still underlies the operation of most gas and gasoline engines today.

Types of internal combustion engines

Piston internal combustion engine

Rotary internal combustion engine

Gas turbine internal combustion engine

• Piston engines - the combustion chamber is contained in a cylinder where thermal energy fuel turns into mechanical energy, which from the translational movement of the piston turns into a rotational one using a crank mechanism.

ICEs are classified:

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

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

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

d) By ignition method (forced ignition, compression ignition, calorific).

e) According to the arrangement 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-rayed and some others.

Gasoline

Gasoline carburetor

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

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

The change in operating strokes is ensured by a special gas distribution mechanism, most often it is represented by one or two camshafts, a system of pushers and valves that directly ensure a phase change. Some internal combustion engines used spool sleeves (Ricardo) for this purpose, having intake 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 windows desired channel. Due to the peculiarities of gas dynamics - the inertia of gases, the time of occurrence of gas wind, the intake, power stroke and exhaust strokes in a real four-stroke cycle overlap, this is called overlapping valve timing. The higher the engine operating speed, the more overlap phases and the larger it is, the less torque of the internal combustion engine at low speeds. Therefore, in modern internal combustion engines, devices are increasingly being used that make it possible to change the valve timing during operation. Engines with electromagnetic valve control (BMW, Mazda) are especially suitable for this purpose. There are also engines with variable compression ratio (SAAB), which have greater flexibility in characteristics.

Two-stroke engines have many layout options and a wide variety of design systems. The basic principle of any two-stroke engine is that the piston performs the functions of a gas distribution element. The work cycle consists, strictly speaking, of three strokes: the power stroke, which lasts from top dead center ( TDC) up to 20-30 degrees to bottom dead center ( BDC), purging, 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 loss of the fresh mixture is inevitable, literally flying into the exhaust pipe (if the internal combustion engine is diesel, we are talking about loss of air), on the other hand, the power stroke lasts not half revolution, but less, which in itself reduces efficiency. At the same time, the duration of the extremely important gas exchange process, which occupies half of the operating cycle in a four-stroke engine, cannot be increased. Two-stroke engines may not have a valve timing system at all. However, if we are not talking about simplified cheap engines, a two-stroke engine is more complex and expensive due to the mandatory use of a blower or a supercharging system; the increased thermal stress of the cylinder-piston engine requires more expensive materials for pistons, rings, and cylinder liners. The piston's performance of the functions of a gas distribution element requires its height to be no 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 power. When power is measured in hundreds of horsepower, the increase in piston mass becomes a very serious factor. The introduction of vertical stroke 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 complex and expensive to implement; except for aviation, such engines were not used anywhere else. Exhaust valves (with direct-flow valve purge) have twice the thermal intensity compared to exhaust valves of four-stroke engines and worst conditions for heat dissipation, and their seats have longer direct contact with the exhaust gases.

The simplest in terms of operating procedure and the most complex in terms of design is the Fairbanks-Morse system, presented in the USSR and Russia, mainly by diesel locomotive 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 20-30 degrees ahead of the intake pistons. Due to this advance, the quality of the purge improves, which in this case is direct-flow, and the filling of the cylinder improves, since at the end of the purge the exhaust ports are already closed. In the 30s - 40s of the twentieth century, schemes with pairs of divergent pistons were proposed - diamond-shaped, triangular; There were aviation diesel engines with three star-shaped diverging pistons, of which two were intake and one was exhaust. In the 20s, Junkers proposed a single-shaft system with long connecting rods connected to the pins of the upper pistons by special rocker arms; the upper piston transmitted forces to the crankshaft through a pair of long connecting rods, and there were three shaft elbows per cylinder. There were also square pistons for purge cavities on the rocker arms. Two-stroke engines with divergent pistons of any system have mainly two disadvantages: firstly, they are very complex and large, and secondly, the exhaust pistons and liners in the area of ​​the exhaust ports have significant temperature stress and a tendency to overheat. Exhaust piston rings are also thermally stressed and are prone to coking and loss of elasticity. These features make the design of such engines a non-trivial task.

CV engines are equipped with a camshaft and exhaust valves. This significantly reduces the requirements for materials and design of the CPG. Intake is through windows in the cylinder liner, opened by the piston. This is exactly how most modern two-stroke diesel engines are configured. The window area and the liner 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, they are used different types crank-chamber contour window-window blowing - loop, return-loop (deflector) in various modifications. To improve engine parameters, various design techniques are used - variable length of the intake and exhaust channels, the number and location of bypass channels can be varied, spool valves, rotating gas shut-off valves, liners and curtains are used that change the height of the windows (and, accordingly, the start of intake and exhaust). Most of these engines are air-passively cooled. Their disadvantages are the relatively low quality of gas exchange and loss of the combustible mixture during purging; in the presence of several cylinders, 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 the internal combustion engine is that it produces its highest power only in a narrow rpm range. Therefore, an integral attribute of an internal combustion engine is transmission. Only in certain cases (for example, in airplanes) can one do without a complex transmission. The idea of ​​a hybrid car, in which the engine always operates in optimal mode, is gradually conquering the world.

In addition, an internal combustion engine requires a power system (for supplying fuel and air - preparing a fuel-air mixture), an exhaust system (for removing exhaust gases), and also cannot do without a lubrication system (designed to reduce friction forces in engine mechanisms and protect parts engine from corrosion, as well as together with the cooling system to maintain optimal thermal regime), cooling systems (to maintain optimal thermal conditions of the engine), starting system (starting methods are used: electric starter, using an auxiliary starting engine, pneumatic, using human muscle power), ignition system (to ignite the fuel-air mixture, used in engines with forced ignition).

see also

• Philippe Le Bon is a French engineer who received a patent in 1801 for an internal combustion engine with compression of a mixture of gas and air.
• Rotary engine: designs and classification
• Rotary piston engine (Wankel engine)

Notes

Links

• Ben Knight “Increasing mileage” // Article about technologies that reduce fuel consumption of automobile internal combustion engines

Internal combustion engine (ICE)- the most common type of passenger car engine. The operation of this type of engine is based on the property of gases to expand when heated. The source of heat in the engine is a mixture of fuel and air (combustible mixture).

There are two types of internal combustion engines: gasoline and diesel. In a gasoline engine, the combustible mixture (gasoline with air) is ignited inside the cylinder from a spark formed at spark plug 3 (Fig. 3). In a diesel engine, the combustible mixture (diesel fuel with air) is ignited by compression, and spark plugs are not used. On both types of engines, the pressure of the combustible gas mixture formed during combustion increases and is transmitted to the piston 7. The piston moves down and through the connecting rod 8 acts on the crankshaft 11, forcing it to rotate. To smooth out jerks and more uniform rotation of the crankshaft, a massive flywheel 9 is installed at its end.

Fig.3. Single cylinder engine diagram.

Let's consider the basic concepts of internal combustion engines and the principle of its operation.

Each cylinder 2 (Fig. 4) has a piston 1. Its uppermost position is called top dead center (TDC), and its lowermost position is called bottom dead center (BDC). The distance traveled by the piston from one dead center to the other is called the stroke of the piston. In one stroke of the piston, the crankshaft will rotate half a revolution.

Fig.4. Cylinder diagram

Combustion chamber (compression)- this is the space between the cylinder head and the piston when it is at TDC.

Cylinder displacement- the space vacated by the piston when it moves from TDC to BDC.

Engine displacement- this is the working volume of all engine cylinders. It is expressed in liters, which is why it is often called engine displacement.

Total cylinder volume- the sum of the volume of the combustion chamber and the working volume of the cylinder.

The compression ratio shows how many times the total volume of the cylinder is greater than the volume of the combustion chamber. The compression ratio for a gasoline engine is 8...10, for an diesel engine it is 20...30.

Compression should be distinguished from compression ratio.

Compression- this pressure in the cylinder at the end of the compression stroke characterizes the technical condition (degree of wear) of the engine. If the compression is greater than or numerically equal to the compression ratio, the engine condition can be considered normal.

Engine power- a quantity showing how much work the engine does per unit time. Power is measured in kilowatts (kW) or horsepower (hp), with one horsepower approximately equal to 0.74 kW.

The engine torque is numerically equal to the product of the force acting on the piston during the expansion of gases in the cylinder and the arm of its action (the radius of the crank is the distance from the axis of the main journal to the axis of the connecting rod journal of the crankshaft). Torque determines the traction force on the wheels of a car: the greater the torque, the better the acceleration dynamics of the car.

Maximum power and torque are developed by the engine at certain crankshaft speeds (indicated in the technical specifications of each car).

Tact- a process (part of the working cycle) that occurs in the cylinder during one stroke of the piston. An engine whose operating cycle occurs in four piston strokes is called four-stroke, regardless of the number of cylinders.

Operating cycle of a four-stroke carburetor engine. It flows in one cylinder in the following sequence (Fig. 5):

Fig.5. Duty cycle of a four-stroke engine

Fig.6. Four-cylinder engine operation diagram

1st stroke - intake. When piston 3 moves downward, a vacuum is formed in the cylinder, under the influence of which a combustible mixture (a mixture of fuel and air) enters the cylinder from the power system through the open inlet valve 1. Together with the residual gases in the cylinder, the combustible mixture forms a working mixture and occupies the entire volume of the cylinder;

2nd stroke - compression. The piston moves upward under the action of the crankshaft and connecting rod. Both valves are closed and the working mixture is compressed to the volume of the combustion chamber;

3rd stroke - power stroke, or expansion. At the end of the compression stroke, an electric spark occurs between the electrodes of the spark plug, which ignites the working mixture (in a diesel engine, the working mixture self-ignites). Under the pressure of expanding gases, the piston moves down and through the connecting rod causes the crankshaft to rotate;

4th measure - release. The piston moves upward, and exhaust gases exit the cylinder through the opened exhaust valve 4.

During the subsequent downward stroke of the piston, the cylinder is filled again working mixture, and the cycle repeats.

Typically, an engine has several cylinders. Domestic cars usually have four-cylinder engines (two-cylinder engines on Oka cars). In multi-cylinder engines, the cylinder strokes follow each other in a certain sequence. The alternation of working strokes or strokes of the same name in the cylinders of multi-cylinder engines in a certain sequence is called the order of operation of the engine cylinders. The cylinder firing order in a four-cylinder engine is most often I -3-4-2 or less commonly I -2-4-3, where the numbers correspond to the cylinder numbers starting from the front of the engine. Scheme in Fig. 6 characterizes the strokes occurring in the cylinders during the first half-turn of the crankshaft. The operating procedure of the engine must be known for the correct connection of high-voltage wires to the spark plugs when setting the ignition timing and for the sequence of adjusting the thermal clearances in the valves.

In fact, any real engine is much more complex than the simplified circuit shown in Fig. 3. Let's consider typical engine design elements and the principles of their operation.

Any motorist has encountered an internal combustion engine. This element is installed on all old and modern cars. Of course, in terms of design features they may differ from each other, but almost all work on the same principle - fuel and compression.

The article will tell you everything you need to know about the internal combustion engine, characteristics, design features, and will also tell you about some of the nuances of operation and Maintenance.

What is ICE

ICE - internal combustion engine. This is exactly how this abbreviation stands for, and no other way. It can often be found on various automotive websites, as well as forums, but as practice shows, not all people know the meaning of this.

What is an internal combustion engine in a car? - This is the power unit that drives the wheels. The internal combustion engine is the heart of any car. Without this structural part, a car cannot be called a car. It is this unit that powers everything, all other mechanisms, as well as electronics.

The motor consists of a series structural elements, which may differ depending on the number of cylinders, injection system and other important elements. Each manufacturer has its own norms and standards for the power unit, but they are all similar to each other.

Origin story

The history of the creation of the internal combustion engine began more than 300 years ago, when the first primitive drawing was made by Leonardo DaVinci. It was its development that laid the basis for the creation of an internal combustion engine, the design of which can be observed on any road.

In 1861, the first design of a two-stroke engine was made based on DaVinci's drawing. At that time there was no talk of installing a power unit on car project, although steam internal combustion engines were already actively used on the railway.

The first to develop a car and introduce internal combustion engines on a large scale was the legendary Henry Ford, whose cars until that time were extremely popular. He was the first to publish the book “Engine: Its Structure and Operation Scheme.”

Henry Ford was the first to calculate such a useful coefficient as the efficiency of an internal combustion engine. This legendary man is considered the progenitor of the automotive industry, as well as part of the aircraft industry.

In the modern world, internal combustion engines are widely used. They are equipped not only in cars, but also in aviation, and due to the simplicity of design and maintenance, they are installed on many types of vehicles and as alternating current electric generators.

Engine operating principle

How does a car engine work? - Many motorists ask this question. We will try to give the most complete and concise answer to this question. The operating principle of an internal combustion engine is based on two factors: injection and compression torque. It is based on these actions that the motor puts everything into action.

If we consider how an internal combustion engine works, then it is worth understanding that there are strokes that divide units into single-stroke, two-stroke and four-stroke. Depending on where the internal combustion engine is installed, the cycles are distinguished.

Modern car engines are equipped with four-stroke “hearts” that are perfectly balanced and work perfectly. But single-stroke and two-stroke engines are usually installed on mopeds, motorcycles and other equipment.

So, let's look at the internal combustion engine and its operating principle, using the example of a gasoline engine:

1. Fuel enters the combustion chamber through the injection system.
2. The spark plugs produce a spark and the fuel-air mixture ignites.
3. The piston, which is located in the cylinder, goes down under pressure, which drives the crankshaft.
4. The crankshaft transmits motion through the clutch and gearbox to the drive shafts, which in turn drive the wheels.

How does an internal combustion engine work?

The structure of a car engine can be considered by the operating cycles of the main power unit. Stroke are a kind of cycles of internal combustion engines, without which it is impossible to do. Let's consider the principle of operation of a car engine from the cycle side:

1. Injection. The piston moves downward, which opens the inlet valve of the corresponding cylinder head and the combustion chamber is filled with an air-fuel mixture.
2. Compression. The piston moves into the VTM and at the highest point a spark occurs, which entails ignition of the mixture, which is under pressure.
3. Working progress. The piston moves into the NTM under the pressure of the ignited mixture and the resulting exhaust gases.
4. Release. The piston moves up, the exhaust valve opens and it pushes the exhaust gases out of the combustion chamber.

All four strokes are also called actual cycles of the internal combustion engine. Thus, a standard four-stroke gasoline engine operates. There is also a five-stroke rotary engine and six-stroke power units of the new generation, but technical specifications and the operating modes of an engine of this design will be discussed in other articles on our portal.

General structure of the internal combustion engine

The structure of an internal combustion engine is quite simple for those who have already encountered their repair, and quite heavy for those who do not yet have an idea about this unit. The power unit includes several important systems in its structure. Let's consider general device engine:

1. Injection system.
2. Cylinder block.
3. Block head.
4. Gas distribution mechanism.
5. Lubrication system.
6. Cooling system.
7. Exhaust gas exhaust mechanism.
8. Electronic part of the engine.

All these elements determine the design and operating principle of the internal combustion engine. Next, it’s worth considering what a car engine consists of, namely the power unit assembly itself:

1. The crankshaft rotates at the very heart of the cylinder block. Activates the piston system. It bathes in oil, so it is located closer to the oil pan.
2. Piston system (pistons, connecting rods, pins, bushings, liners, yokes and oil rings).
3. Cylinder head (valves, oil seals, camshaft and other timing elements).
4. Oil pump - circulates lubricating fluid throughout the system.
5. Water pump (pump) - circulates the coolant.
6. The gas distribution mechanism kit (belt, rollers, pulleys) ensures correct timing. Not a single internal combustion engine, the operating principle of which is based on strokes, can function without this element.
7. Spark plugs ensure ignition of the mixture in the combustion chamber.
8. Intake and exhaust manifold - their operating principle is based on the intake of the fuel mixture and the release of exhaust gases.

The general structure and operation of an internal combustion engine is quite simple and interconnected. If one of the elements fails or is missing, then operation car engines will be impossible.

Classification of internal combustion engines

Car engines are divided into several types and classifications, depending on the design and operation of the internal combustion engine. Classification of internal combustion engines according to international standards:

1. For the type of injection of the fuel mixture:
   • Those that run on liquid fuels (gasoline, kerosene, diesel fuel).
   • Those that run on gaseous fuels.
   • Those that operate on alternative sources (electricity).

1. Consisting of work cycles:
   • 2 stroke
   • 4 stroke

1. According to the method of mixture formation:
   • with external mixture formation (carburetor and gas power units),
   • with internal mixture formation (diesel, turbodiesel, direct injection)

1. According to the method of ignition of the working mixture:
   • with forced ignition of the mixture (carburetor, engines with direct injection of light fuels);
   • with compression ignition (diesels).

1. By number and arrangement of cylinders:
   • one-, two-, three-, etc. cylinder;
   • single row, double row

1. According to the method of cooling the cylinders:
   • with liquid cooling;
   • air cooled.

Operating principles

Car engines operate with different service life. The simplest engines can have a service life of 150,000 km with proper maintenance. But some modern diesel engines that are equipped in trucks can last up to 2 million.

When designing an engine, automakers usually focus on the reliability and technical characteristics of power units. Considering modern trend, many car engines are designed for a short but reliable service life.

Thus, the average operation of a passenger vehicle power unit is 250,000 km. And then there are several options: recycling, contract engine or major overhaul.

Maintenance

Engine maintenance remains an important factor in operation. Many motorists do not understand this concept and rely on the experience of car services. What is meant by car engine maintenance:

1. Changing engine oil in accordance with technical data sheets and manufacturer's recommendations. Of course, each automaker sets its own limits for changing the lubricant, but experts recommend changing the lubricant once every 10,000 km for gasoline internal combustion engines, 12-15 thousand km for a diesel engine and 7000-9000 km for a vehicle running on gas.
2. Replacing oil filters. This is carried out at every oil change.
3. Replace fuel and air filters - once every 20,000 km.
4. Cleaning injectors - every 30,000 km.
5. Replacement of the gas distribution mechanism - once every 40-50 thousand kilometers or as necessary.
6. All other systems are checked at every maintenance, regardless of how long ago the elements were replaced.

With timely and complete maintenance, the service life of the vehicle engine increases.

Engine modifications

Tuning is the modification of an internal combustion engine to increase certain indicators, such as power, dynamics, consumption or others. This movement gained worldwide popularity in the early 2000s. Many car enthusiasts began to independently experiment with their power units and post photo instructions on the global network.

Now you can find a lot of information on the modifications carried out. Of course, not all of this tuning has an equally good effect on the condition of the power unit. So, it is worth understanding that overclocking power without complete analysis and tuning can “ruin” the internal combustion engine, and the wear rate increases several times.

Based on this, before tuning the engine, you should carefully analyze everything so as not to “get into trouble” with a new power unit, or, even worse, not to get into an accident, which could be the first and last for many.

Conclusion

The design and features of modern engines are constantly being improved. Thus, it is no longer possible to imagine the whole world without exhaust gases, cars and car services. A running internal combustion engine can be easily recognized by its characteristic sound. The principle of operation and structure of the internal combustion engine is quite simple, if you understand it once.

As for technical maintenance, it will help to look at the technical documentation. But, if a person is not sure that he can carry out maintenance or repair of the car with his own hands, then he should contact a car service center.

Few people know that the internal combustion engine was invented 5 centuries ago by the legendary engineer and designer Leonardo da Vinci. But after the first drawing, it took another 300 years for the first prototypes to be created that could fully work.

Types of engines

The first full-fledged prototype of an internal combustion engine was designed back in 1806, which belonged to the Niepcier brothers. After this important historical fact there was a short lull.

But, at the end of the 19th century, three legendary Germans launched the automotive industry - Nicholas Otto, Gottlieb Daimler and Wilhelm Maybach. After this, internal combustion engines received many modifications and variants that are still used today.

Let's consider what types of automobile internal combustion engines exist, and also indicate the types of engines:

• Steam engine
• Gas engine
• Carburetor injection system
• Injector
• Diesel engines
• Gas engine
• Electric motors
• Rotary piston internal combustion engines

Steam engine

The first representative of a full-fledged internal combustion engine should be considered a steam engine, which was installed on all vehicles 19th century, until the invention of other types of motors.

At that time, locomotives, cars, and even primitive three-wheeled self-propelled vehicles (resembling motorcycles) were equipped with steam engines. An invention of this class conquered the whole world, but by the end of the 19th and beginning of the 20th century it became ineffective, since steam vehicles could not reach a sufficiently high speed.

Gas engine

A gasoline engine is an internal combustion engine, which is fueled by gasoline. Fuel is supplied from the fuel tank using a pump (mechanical or electric) to the injection system. So, let's look at what types of gasoline engines there are:

• With carburetor.
• Injection type.

The modern world is accustomed to the fact that most cars have an electronic fuel injection system (injector).

Carburetor injection system

A carburetor is a type of fuel injection device into the intake manifold with further distribution among the cylinders. The first primitive carburetor was developed in Germany at the end of the 19th century and has almost 100 summer story development.

Carburetors come in one, two, four and six chamber types. In addition, there are quite a lot of prototypes.

The principle of operation of the carburetor is quite simple: the fuel pump supplies fuel to the float chamber, where gasoline passes through the nozzles mechanically (the amount of injected fuel is regulated by the driver using the accelerator pedal), and is supplied to the intake manifold. The disadvantage of the carburetor is that it is sensitive to adjustments and also does not comply with international environmental standards.

Injector

An injection engine is a type of fuel injection device into the engine cylinders. Injection injection can be mono or split. Today, this system is increasingly being improved to reduce CO2 emissions into the atmosphere. For injection, nozzles are used, which began to be used on diesel engines even earlier.

With the transition to this system, vehicles began to be equipped with electronic engine control units to adjust the composition of the air-fuel mixture, as well as signal malfunctions within the system.

Diesel engines

A diesel engine is a type of engine that consumes diesel fuel like combustible fuel. The main systems and elements of the engine are identical to its gasoline brother, the difference lies in the injection system and ignition of the mixture. There are no spark plugs in a diesel engine, since the mixture does not need to be ignited by a spark.

On engines of this type, glow plugs are installed, which heat the air in the combustion chamber, which exceeds the ignition temperature. After this, atomized fuel is supplied through the injectors, which burns, thereby creating sufficient pressure to drive the piston, which spins the crankshaft.

Turbodiesel is considered one of the subtypes of diesel internal combustion engines. This engine has a turbine that has the shape of a snail. With the help of a turbine, a larger amount of compressed air is supplied to the engine, which gives a greater detonation effect, due to which the engine can be accelerated faster.

Gas engine

Gas engines today are almost never used in the automotive industry in their pure form, since frequent engine breakdowns have led to their complete abandonment. Instead, gas installations can often be found on gasoline cars, which significantly saves money on fuel.

Gas from the cylinder is supplied to the gearbox, which distributes the fuel among the cylinders, and then the fuel enters directly into the combustion chambers. The gas is then ignited with the help of spark plugs. The only downside to using gas installation it is believed that the motor loses 20% of its potential resource.

Electric motors

Nicholas Tesla first proposed the use of electricity for cars. Electric motors are not common today, since the battery charge only lasts up to 200 km, and there are practically no gas stations that can provide a car charging service.

The well-known global company, the manufacturer of electric cars Tesla, continues to improve electric motors, and every year gives consumers new products that have a greater range without recharging.

Hybrids

Probably the most desirable engines today. It is a mixture of a gasoline internal combustion engine and an electric motor. There are several options for how this engine works.

1. The motor can operate on alternating power supply. The vehicle is initially driven on gasoline while the generator charges the battery, and then the driver can switch to electric power.
2. The engine and electric motor operate simultaneously, which helps save fuel consumption by one and the same distance with other types of internal combustion engines.

Rotary piston internal combustion engines

The rotary piston power unit is not widely used in the automotive industry, although you can find car models that use this type of internal combustion engine. The creation of such a motor was proposed by the designer Wankel.

The movement is carried out due to the rotation of a three-tooth rotor, which allows for any 4-stroke cycle of a Diesel, Stirling or Otto without the use of a special gas distribution mechanism. This motor was actively used in the 80s 20 st.

Hydrogen motor

KNOW-HOW modern world considered a hydrogen engine. A hydrogen type unit is installed in the car. The difference from gasoline engines is the fuel supply. If for gasoline fuel is supplied at the time the piston returns to the HTM, then for a hydrogen power unit at the moment when the piston returns to the HTM.

In the future, it is planned to create a closed-type hydrogen engine, when there will be no need to emit exhaust gases, and at 500 km the car owner will be able to forget about refueling the car.

It is worth understanding that cars with such an engine will not be very cheap until they completely supplant their gasoline brother.

Conclusion

Internal combustion engines have a fairly large number of types and types, to suit every taste. Thus, according to global statistics, gasoline, diesel and hybrid power units are considered the most popular. But everything is moving towards the fact that people want to move away from using gasoline and its analogues and switch completely to electric power.

In an engine design, the piston is a key element of the working process. The piston is made in the form of a metal hollow glass, located with a spherical bottom (piston head) upwards. The guide part of the piston, otherwise called the skirt, has shallow grooves designed to hold the piston rings in them. The purpose of the piston rings is to ensure, firstly, the tightness of the space above the piston, where during engine operation instantaneous combustion of the gasoline-air mixture occurs and the resulting expanding gas could not go around the skirt and rush under the piston. Secondly, the rings prevent oil located under the piston from entering the space above the piston. Thus, the rings in the piston act as seals. The lower (lower) piston ring is called the oil scraper ring, and the upper (upper) is called the compression ring, that is, providing a high degree of compression of the mixture.

When a fuel-air or fuel mixture enters the cylinder from a carburetor or injector, it is compressed by the piston as it moves upward and ignited by an electric discharge from the spark plug (in a diesel engine, the mixture self-ignites due to sudden compression). The resulting combustion gases have a significantly larger volume than the original fuel mixture, and, expanding, sharply push the piston down. Thus, the thermal energy of the fuel is converted into reciprocating (up and down) movement of the piston in the cylinder.

Next, you need to convert this movement into shaft rotation. This happens as follows: inside the piston skirt there is a pin on which the upper part of the connecting rod is fixed, the latter is pivotally fixed to the crankshaft crank. The crankshaft rotates freely on support bearings located in the crankcase of the internal combustion engine. When the piston moves, the connecting rod begins to rotate the crankshaft, from which torque is transmitted to the transmission and then through the gear system to the drive wheels.

Engine Specifications.Engine Characteristics When moving up and down, the piston has two positions called dead centers. Top dead center (TDC) is the moment of maximum lift of the head and the entire piston up, after which it begins to move down; bottom dead center (BDC) is the lowest position of the piston, after which the direction vector changes and the piston rushes upward. The distance between TDC and BDC is called the piston stroke, the volume of the upper part of the cylinder when the piston is at TDC forms the combustion chamber, and the maximum volume of the cylinder when the piston is at BDC is usually called the total volume of the cylinder. The difference between the total volume and the volume of the combustion chamber is called the working volume of the cylinder.
The total working volume of all cylinders of an internal combustion engine is indicated in the technical characteristics of the engine, expressed in liters, therefore in everyday life it is called the engine displacement. The second most important characteristic of any internal combustion engine is the compression ratio (CR), defined as the quotient of the total volume divided by the volume of the combustion chamber. For carburetor engines, CC varies from 6 to 14, for diesel engines - from 16 to 30. It is this indicator, along with engine volume, that determines its power, efficiency and completeness of combustion of the fuel-air mixture, which affects the toxicity of emissions during internal combustion engine operation. .
Engine power has a binary designation - in horsepower (hp) and in kilowatts (kW). To convert units from one to another, a coefficient of 0.735 is used, that is, 1 hp. = 0.735 kW.
The working cycle of a four-stroke internal combustion engine is determined by two revolutions of the crankshaft - half a revolution per stroke, corresponding to one piston stroke. If the engine is single-cylinder, then unevenness is observed in its operation: a sharp acceleration of the piston stroke during explosive combustion of the mixture and a slowdown as it approaches BDC and beyond. In order to stop this unevenness, a massive flywheel disk with high inertia is installed on the shaft outside the motor housing, due to which the torque of the shaft becomes more stable over time.

Operating principle of an internal combustion engine
Modern car, most often, is driven by an internal combustion engine. There are a huge variety of such engines. They differ in volume, number of cylinders, power, rotation speed, fuel used (diesel, gasoline and gas internal combustion engines). But, in principle, the structure of the internal combustion engine is similar.
How does the engine work and why is it called a four-stroke internal combustion engine? It’s clear about internal combustion. Fuel burns inside the engine. Why 4 strokes of the engine, what is it? Indeed, there are also two-stroke engines. But they are used extremely rarely on cars.
A four-stroke engine is called because its work can be divided into four equal parts. The piston will pass through the cylinder four times - twice up and twice down. The stroke begins when the piston is at its lowest or highest point. For motorist mechanics, this is called top dead center (TDC) and bottom dead center (BDC).
The first stroke is the intake stroke

The first stroke, also known as the intake stroke, begins at TDC (top dead center). Moving down, the piston sucks the air-fuel mixture into the cylinder. This stroke operates when the intake valve is open. By the way, there are many engines with multiple intake valves. Their number, size, and time spent in the open state can significantly affect engine power. There are engines in which, depending on the pressure on the gas pedal, there is a forced increase in the time the intake valves are open. This is done to increase the amount of fuel drawn in, which, once ignited, increases engine power. The car, in this case, can accelerate much faster.

The second stroke is the compression stroke

The next stroke of the engine is the compression stroke. After the piston has reached the bottom point, it begins to rise, thereby compressing the mixture that entered the cylinder during the intake stroke. The fuel mixture is compressed to the volume of the combustion chamber. What kind of camera is this? The free space between the top of the piston and the top of the cylinder when the piston is at top dead center is called the combustion chamber. The valves are completely closed during this cycle of engine operation. The more tightly they are closed, the better the compression occurs. Great importance has, in this case, the condition of the piston, cylinder, piston rings. If there are large gaps, then good compression will not work, and accordingly, the power of such an engine will be much lower. Compression can be checked special device. Based on the compression level, we can draw a conclusion about the degree of engine wear.

The third stroke is the power stroke

The third stroke is the working one, starting at TDC. It is no coincidence that he is called a worker. After all, it is in this beat that the action that makes the car move occurs. At this stroke, the ignition system comes into operation. Why is this system called that? Yes, because it is responsible for igniting the fuel mixture compressed in the cylinder in the combustion chamber. It works very simply - the system spark plug gives a spark. In fairness, it is worth noting that the spark is produced at the spark plug a few degrees before the piston reaches the top point. These degrees, in a modern engine, are regulated automatically by the “brains” of the car.
After the fuel ignites, an explosion occurs - it sharply increases in volume, forcing the piston to move down. The valves in this stroke of the engine, as in the previous one, are in a closed state.

The fourth stroke is the release stroke

The fourth stroke of the engine, the last one is exhaust. Having reached the bottom point, after the power stroke, the exhaust valve in the engine begins to open. There can be several such valves, like intake valves. Moving upward, the piston removes exhaust gases from the cylinder through this valve - ventilates it. The degree of compression in the cylinders depends on the precise operation of the valves, complete removal exhaust gases and the required amount of intake fuel-air mixture.

Gas distribution mechanism

The gas distribution mechanism (GRM) is designed for fuel injection and exhaust gas release in internal combustion engines. The gas distribution mechanism itself is divided into lower valve, when the camshaft is located in the cylinder block, and overhead valve. The overhead valve mechanism means that the camshaft is located in the cylinder head (cylinder head). There are also alternative valve timing mechanisms, such as a sleeve timing system, a desmodromic system and a variable-phase mechanism.
For two-stroke engines, the valve timing mechanism is carried out using inlet and outlet ports in the cylinder. For four-stroke engines, the most common system is overhead valve, which will be discussed below.

Timing device
At the top of the cylinder block there is a cylinder head (cylinder head) with a camshaft, valves, pushers or rocker arms located on it. The camshaft drive pulley is located outside the cylinder head. To prevent engine oil from leaking from under the valve cover, an oil seal is installed on the camshaft journal. The valve cover itself is installed on an oil-gasoline-resistant gasket. The timing belt or chain fits onto the camshaft pulley and is driven by the crankshaft gear. Tension rollers are used to tension the belt, and tension shoes are used for the chain. Typically, the timing belt drives the water pump for the cooling system, the intermediate shaft for the ignition system, and the pump drive. high pressure Injection pump (for diesel options).
WITH opposite side camshaft by direct drive or belt, can drive a vacuum booster, power steering or a car alternator.

The camshaft is an axis with cams machined on it. The cams are located along the shaft so that during rotation, in contact with the valve tappets, they are pressed exactly in accordance with the engine’s power strokes.
There are engines with two camshafts (DOHC) and a large number of valves. As in the first case, the pulleys are driven by a single timing belt and chain. Each camshaft closes one type of intake or exhaust valve.
The valve is pressed by a rocker arm (early versions of engines) or a pusher. There are two types of pushers. The first is pushers, where the gap is adjusted by calibration washers, the second is hydraulic pushers. The hydraulic tappet softens the blow to the valve thanks to the oil contained in it. There is no need to adjust the clearance between the cam and the top of the tappet.

crank mechanism

The crank mechanism (hereinafter abbreviated as CSM) is an engine mechanism. The main purpose of the crankshaft is to transform the reciprocating movements of the piston cylindrical into the rotational movements of the crankshaft in an internal combustion engine and vice versa.

KShM device
Piston

The piston has the form of a cylinder made of aluminum alloys. The main function of this part is to turn into mechanical work a change in gas pressure, or vice versa, an increase in pressure due to reciprocating motion.
The piston consists of a bottom, head and skirt put together, which perform completely different functions. The piston bottom, which is flat, concave or convex, contains a combustion chamber. The head has cut grooves where the piston rings (compression and oil scraper) are placed. Compression rings prevent gases from blowing into the engine crankcase, and piston oil scraper rings help remove excess oil from the inner walls of the cylinder. There are two bosses in the skirt that provide placement of the piston pin connecting the piston to the connecting rod.

A stamped or forged steel (less commonly titanium) connecting rod has hinged joints. The main role of the connecting rod is to transmit piston force to the crankshaft. The design of the connecting rod assumes the presence of an upper and lower head, as well as a rod with an I-section. The upper head and bosses contain a rotating (“floating”) piston pin, and the lower head is removable, thereby allowing for a close connection with the shaft journal. Modern technology controlled splitting of the lower head allows for high precision in joining its parts.

The flywheel is installed at the end of the crankshaft. Today, dual-mass flywheels, which have the form of two elastically connected disks, are widely used. The flywheel ring gear is directly involved in starting the engine through the starter.

Block and cylinder head

The cylinder block and cylinder head are cast from cast iron (less commonly, aluminum alloys). The cylinder block contains cooling jackets, beds for crankshaft and camshaft bearings, as well as mounting points for instruments and components. The cylinder itself acts as a guide for the pistons. The cylinder head contains a combustion chamber, intake and exhaust ports, special threaded holes for spark plugs, bushings and pressed seats. The tightness of the connection between the cylinder block and the head is ensured by the gasket. In addition, the cylinder head is closed with a stamped cover, and between them, as a rule, a gasket made of oil-resistant rubber is installed.