Types of gasoline engines. Electric motors

31.03.2019

ICE is an engine that works on the principle of combustion various fuels directly inside the unit. Unlike engines of another type, internal combustion engines are deprived of: any elements that transfer heat for further conversion into mechanical energy, the conversion occurs directly from the combustion of fuel; much more compact; have a low weight relative to other types of units with comparable power; require the use of certain fuels with stringent specifications for combustion temperature, volatility, octane rating, etc.

Used in the automotive industry four stroke motors:

1. Inlet;

2. Compression;

3. working stroke;

4. Release.
But there are also two-stroke versions of engines. internal combustion, but in modern world they are of limited use.

In this article, only motors installed on cars will be considered.

Types of engines by fuel used

Petrol engines, as the name implies, they use gasoline with a different octane number as a fuel for work, and have a system for forced ignition of the fuel mixture using an electric spark.

They can be divided according to the type of intake into carburetor and injection. Carburetor engines are already disappearing from production due to the difficulty in fine-tuning, high consumption gasoline, the inefficiency of mixing the fuel mixture and inconsistencies with modern hard environmental requirements. In such motors, mixing combustible mixture starts in the chambers of the carburetor and ends along the way in the intake manifold.

Injection units are developing at a fast pace, and the fuel injection system is improving with each generation. The first injectors had a "mono-injection" with a single nozzle. In fact, it was the modernization of carburetor engines. Over time, on most units, systems with separate nozzles for each cylinder began to be used. The use of injectors in the intake system made it possible to more accurately control the proportions of fuel and air in different operating modes of the unit, reduce fuel consumption, improve the quality of the fuel mixture, increase power and environmental friendliness power units.

Modern injectors installed on power units with a direct fuel injection system into the cylinders are capable of producing several separate fuel injections in one cycle. This allows you to further improve the quality of the fuel mixture and achieve maximum energy return from the amount of gasoline used. That is, the economy and performance of the motors have increased even more.

Diesel units- use the principle of ignition of a mixture of diesel fuel and air when heated from strong compression. At the same time, forced ignition systems are not used in diesel units. These engines have a number of advantages over gasoline engines, primarily fuel economy (up to 20%), with comparative power. Fuel is consumed less due to the higher compression ratio in the cylinders, which improves the combustion characteristics and energy transfer of the fuel mixture, and therefore, less fuel is needed to achieve the same results. In addition, diesel units do not use throttle valves, which improves the flow of air into the power unit, which further reduces fuel consumption. Diesel engines develop more torque, and for more low revs crankshaft.

Not without drawbacks. Due to the increased load on the cylinder walls, the designers had to use more reliable materials and increase the size of the structure (increased weight and increased production costs). In addition, the operation of a diesel power unit is loud due to the characteristics of fuel ignition. And the increased mass of parts does not allow the engine to develop high speeds at the same speed as gasoline ones, and the maximum crankshaft speed is lower than that of gasoline units.

A variety of internal combustion engines by design

Hybrid powertrain

This type of car began to gain popularity in recent years. Due to its fuel saving efficiency and increased total power vehicle by combining two types of units. In fact, this design consists of two separate units - a small internal combustion engine (most often diesel) and an electric motor (or several electric motors) with a large capacity battery.

The advantages of combining are expressed in the ability to combine the energy of two units during acceleration, or the use of each type of engine separately, depending on the need. For example, when driving in a city traffic jam, only the electric motor can work, saving diesel fuel. When driving on country roads, the internal combustion engine works as a more enduring, powerful unit with a large power reserve.

At the same time, a special battery for electric motors can be recharged from a generator, or using a recuperation system during braking, which saves not only fuel, but also the electricity needed to charge the battery.

Rotary piston motor

The rotary piston motor is built according to a unique scheme of movement of the piston-rotor, which moves inside the cylinder not along a reciprocating path, but around its axis. This is due to the special triangular design of the piston and the special arrangement of the intake and exhaust ports in the cylinder.

Thanks to this design, the engine quickly picks up speed, which increases dynamic characteristics car. But with the development of the classical design of internal combustion engines, the Wankel engine began to lose its relevance due to design limitations. The principle of piston movement does not allow achieving a high degree of compression of the fuel mixture, which excludes the use of diesel fuel. A small resource, the complexity of maintenance and repair, as well as poor environmental performance do not allow automakers to develop this area.

Varieties of power units by layout

Due to the need to reduce weight and dimensions, as well as the placement of a larger number of pistons in one unit, it led to the emergence of varieties of motors in terms of layout.

inline motors

The in-line engine is the most classic version of the power unit. In which all pistons and cylinders are arranged in one row. Wherein, modern motors with an in-line layout, they can accommodate no more than six cylinders. But it is six-cylinder in-line engines that have best performance to balance vibration during operation. The only negative is the significant length of the motor, relative to other layouts.

V-motors

These motors appeared as a result of the desire of designers to reduce the dimensions of the engines, and the need to place more than six pistons in one block. In these motors, the cylinders are in different planes. Visually, the arrangement of the cylinders forms the letter "V", hence the name. The angle between the two rows is called the camber angle, and varies over a wide range, dividing this type of motor into subgroups.

Boxer motors

Boxer engines received a maximum camber angle of 180 degrees. That allowed the designers to reduce the height of the unit to a minimum size, and distribute the load on crankshaft, increasing its resource.

VR motors

This is a combination of the properties of in-line and V-shaped units. The camber angle in such engines reaches 15 degrees, which allows the use of one cylinder head with a single gas distribution mechanism.

W motors

One of the most powerful and "extreme" ICE designs. They can have three rows of cylinders with a large camber angle, or two combined VR blocks. To date, engines for eight and twelve cylinders have become widespread, but the design allows the use of more cylinders.

Characteristics of the internal combustion engine

After reviewing a lot of information about various cars, any interested person will see certain basic parameters of the motor:

The power of the power unit, measured in hp. (or kWh);

The maximum torque developed by the power unit, measured in N / m;

Most motorists share power units, only in terms of power. But this division is not entirely correct. Of course, a 200-horsepower unit is preferable to a 100-horsepower engine on a heavy crossover. And for a light urban hatchback, a 100 horsepower engine is enough. But there are some nuances.

Max power, specified in the technical documentation, is achieved at certain crankshaft speeds. But using the car in urban conditions, the driver rarely spins the engine above 2,500 rpm. Therefore, the greater the time of operation of the machine, only a part of the potential power is involved.

But, often, there are cases on the road. When it is necessary to sharply increase the speed to overtake, or to avoid emergency. It is the maximum torque that affects the ability of the unit to quickly gain the required speed and power. To put it simply, torque affects the dynamics of the car.

It is worth noting a slight difference between gasoline and diesel engines. The gasoline-powered engine produces maximum torque at crankshaft speeds from 3,500 to 6,000 per minute, and diesel engines can reach maximum parameters at lower speeds. Therefore, it seems to many. That diesel units are more powerful and “pull” better. But, most of the most powerful units use gasoline fuel, as they are able to develop a higher number of revolutions per minute.

And for a detailed understanding of the term torque, you should look at its units of measurement: Newtons multiplied by meters. In other words, torque determines the force with which the piston presses on the crankshaft, which in turn transmits power to the gearbox, and ultimately to the wheels.

Also, you can mention powerful technique, in which the maximum torque can be achieved at a speed of 1,500 per minute. Basically, these are tractors, powerful dump trucks, and some diesel all-terrain vehicles. Naturally, such machines do not need to spin the motor to the maximum speed.

Based on the information provided, we can conclude that the torque depends on the volume of the power unit, its dimensions, the dimensions of the parts and their weight. The heavier all these elements, the more torque prevails at low revs. Diesel units have more torque and lower crankshaft speeds (the large inertia of the heavy crankshaft and other elements do not allow high speeds to be developed).

Car engine power

It is worth recognizing that power and torque are interrelated parameters that depend on each other. Power is a certain amount of work done by the motor in time. In turn, the work of the motor is the torque. Therefore, power is characterized as the amount of torque per unit of time.

There is a well-known formula that characterizes the ratio of power and torque:

Power = Torque * RPM / 9549

As a result, we get the value of power in kilowatts. But naturally, looking at the characteristics of cars, we are more accustomed to seeing indicators in “hp”. To convert kilowatts to hp. it is necessary to multiply the resulting value by 1.36.

Conclusion

As it became clear from this article, car engines internal combustion can have many differences from each other. And choosing a car for permanent use- it is necessary to study all the nuances of the design, characteristics, economy, environmental friendliness, power and reliability of the power unit. Also, it will be useful to study information about the maintainability of the motor. Since many modern units use complex gas distribution, fuel injection and exhaust systems, which can complicate their repair.

(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 the conversion of the combustion energy of the fuel charge into mechanical useful work.

Despite general principle action, 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 internal combustion engines are, and what are their main features and differences.

Read in this article

Types of internal combustion engines

Let's start with the fact that the internal combustion engine can be two-stroke and four-stroke. Concerning automobile motors, these units are four-stroke. Engine cycles are:

inlet fuel-air mixture or air (depending on the type of internal combustion engine);
compression of a mixture of fuel and air;
fuel charge combustion and power stroke;
release from the combustion chamber of exhaust gases;

Both gasoline and diesel engines operate on this principle. piston engines, which are widely used in cars and other equipment. It is also worth mentioning, in which gas fuel burns similarly to diesel fuel or gasoline.

Petrol power units

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

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

This solution allows you to supply fuel 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 gets the opportunity to work on lean mixture(for example, engines of the GDI family), fuel consumption decreases, exhaust toxicity decreases, etc.

Diesel engines

It runs on diesel fuel, and is also significantly different from gasoline. The main difference is the absence of a spark ignition system. The ignition of the mixture of fuel and air in a diesel engine comes from compression.

Simply put, air is compressed in the cylinders, which heats up a lot. At the last moment, injection occurs directly into the combustion chamber, after which the heated and highly compressed mixture ignites on its own.

If we compare diesel and gasoline ICEs, diesel is more economical, the best efficiency and maximum, which is available at low revs. Taking into account the fact that diesel engines develop more traction at lower crankshaft speeds, in practice such a motor does not need to be “turned” at the start, and you can also count on a confident pickup from the very bottom.

However, in the list of disadvantages of such units, one can single out, as well as more weight and lower speeds in the mode maximum speed. The fact is that the diesel engine is initially “low-speed” and has a lower rotational speed compared to gasoline internal combustion engines.

Diesels also have a greater mass, since the features of compression ignition imply more serious loads on all elements of such an assembly. In other words, the parts in a diesel engine are stronger and heavier. Also, diesel engines are noisier, 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 reciprocate in the cylinder are simply absent. The main element of a rotary motor is the rotor.

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

The advantages include compactness, high power with a small working volume, as well as the ability to quickly spin up to high speed. 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 flow fuel. Also, a rotary engine is characterized by increased toxicity, that is, it does not quite fit into modern environmental standards.

hybrid engine

On some internal combustion engines, to obtain the necessary power, it is used in combination with a turbocharger, while on others with exactly the same displacement and layout, such solutions are not available.

For this reason, for an objective assessment of the performance of a particular engine at different speeds, and not on the crankshaft, but on the wheels, it is necessary to carry out special complex measurements on a dyno.

The principle of operation of internal combustion engines

Main principle ICE operation is based on the fact that the fuel (solid, liquid or gaseous) burns in a specially allocated working volume inside the unit itself, converting thermal energy into mechanical energy.

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

To date, the ICE device can have three main types:

often called easy;
four-stroke power unit, allowing to achieve higher power and efficiency values;
with enhanced power characteristics.

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

Benefits of internal combustion engines

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

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

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

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

Brief historical excursion

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

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

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

The main types and types of internal combustion engines

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

Gasoline engines

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

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

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

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

Diesel engines

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

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

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

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

gas engines

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

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

Combined types of internal combustion engines

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

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

Maintenance and repair of internal combustion engines

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

Especially for inquisitive minds who want to independently comprehend all the mysteries and secrets of almost any vehicle, approximate principal internal combustion engine scheme shown in the photo above.

So, we found out what this power unit is.

Automotive reciprocating internal combustion engines (ICE) have many indicators - power, torque, fuel consumption, emissions of harmful substances, etc., which largely depend on their design parameters. Engine types Engine - a device that converts the energy of combustion of fuel into mechanical work. Almost all car engines operate on a cycle consisting of four cycles: air intake or its mixture with fuel; compression of the working mixture, working stroke during the combustion of the working mixture; release of exhaust gases. Piston engines - gasoline and diesel engines - are most widely used in cars. Petrol engines have forced ignition fuel-air mixture spark candles. They differ in the type of power system: in carburetors, the mixing of gasoline with air begins in the carburetor and continues in the intake manifold. Currently, the production of such engines is declining due to low efficiency and inconsistency with modern environmental regulations; in injection engines, fuel can be supplied by one injector (nozzle) to a common intake pipeline (central, single injection) or by several injectors before the intake valves of each cylinder (ported injection). In them, a slight increase in maximum power and a decrease in gasoline consumption and exhaust gas toxicity are possible due to a more accurate dosage of fuel. electronic system engine management; engines with direct injection of gasoline into the combustion chamber, which is fed into the cylinder in several portions, which optimizes the combustion process, allows the engine to run on lean mixtures, respectively, reduces fuel consumption and emissions of harmful substances. diesel engine- engines in which the ignition of the mixture of fuel with air occurs from an increase in its temperature during compression. Compared to gasoline engines, these engines have better efficiency (by 15-20%) due to a higher (two or more times) compression ratio (see below), which improves the combustion of the fuel-air mixture. The advantage of diesels is the absence throttle valve, which creates resistance to the movement of air at the intake and increases fuel consumption. The maximum torque (see below) is developed by diesel engines at a lower crankshaft speed (in everyday life - "high-torque at the bottom"). Diesel engines of outdated designs had a number of disadvantages compared to gasoline engines: greater weight and cost at the same power due to the high compression ratio (1.5-2 times more), which increased the pressure in the cylinders and the load on the parts, which made it necessary to produce more durable engine elements, increasing their dimensions and weight; greater noise due to the peculiarities of the combustion process of fuel in the cylinders; lower maximum crankshaft speed due to the higher mass of parts, which caused large inertial loads. For the same reason, diesel engines, as a rule, are less responsive - they gain momentum more slowly. Rotary piston engine(Wankel)- in it, the rotor-piston does not reciprocate, as in gasoline engines and diesel engines, but rotates along a certain trajectory. Thanks to this, it has good throttle response - it quickly gains momentum, providing the car with good acceleration dynamics. Due to design features, the compression ratio is limited, therefore it only works on gasoline and has the worst efficiency due to the shape of the combustion chamber. Previously, its disadvantage was a smaller resource, and now low environmental performance, which is now receiving much attention. hybrid power point is a combination of a piston engine (usually a diesel engine), an electric motor, a generator and traction batteries (a traction battery, unlike a starter battery, is designed to discharge high currents(50-100 A) for 30-60 minutes) batteries. The operation of this installation takes place in various modes depending on the nature of the vehicle. During intensive acceleration, the piston and electric motors. During engine braking, the alternator charges the batteries with deceleration energy. When driving in the urban cycle, only the electric motor can work. All this allows, while maintaining (or even improving) the dynamics of acceleration, significantly increase efficiency and reduce emissions of harmful substances.

Piston engine layout

A significant variety of piston engine layouts is associated with their placement in a car and the need to fit a certain number of cylinders in a limited volume of the engine compartment. An in-line engine (Fig. 1, a) is a layout in which all cylinders are in the same plane. Applies to a small number of cylinders (2, 3, 4, 5 and 6). inline six-cylinder engine most easily balanced (reduced vibrations), but has a considerable length.

V-shaped engine (Fig. 1, b) - its cylinders are located in two planes, as if forming the Latin letter V. The angle between these planes is called the camber angle. Most often, this arrangement of cylinders is used for six- and eight-cylinder engines and is designated V6 and V8, respectively. This arrangement allows you to reduce the length of the engine, but increases its width.

The boxer engine (Fig. 1, c) has a camber angle of 180°, due to which its unit height is the smallest among all layouts.

The VR engine (Fig. 1, d) has a small camber angle (about 15°), which makes it possible to reduce both the longitudinal and transverse dimensions of the unit.

The W-engine has two layout options - three rows of cylinders with a large camber angle (Fig. 1, e) or, as it were, two VR-layouts (Fig. 1, f). Provides good compactness even with in large numbers cylinders. Currently, W8 and W12 are mass-produced.

Any engine is characterized by the following structurally specified parameters (Fig. 2), which are practically unchanged during the operation of the vehicle.

Combustion chamber volume- the volume of the cylinder cavity and the recess in the head above the piston located at the top dead center - the extreme position at the greatest distance from the crankshaft. Cylinder displacement- the space that the piston frees when moving from top to bottom dead center. The latter is extreme position piston on closest distance from the crankshaft. Full cylinder volume- is equal to the sum of the working volume and the volume of the combustion chamber. The working volume of the engine (displacement) is the sum of the working volumes of all cylinders. Compression ratio- the ratio of the total volume of the cylinder to the volume of the combustion chamber. This parameter shows how many times the total volume decreases when the piston moves from bottom dead center to top. For petrol engines octane number the fuel used. The parameters of the engine are the quantities that characterize its operation. In addition to design parameters, they depend on the features and settings of power and ignition systems, the degree of wear of parts, etc. The pressure at the end of the compression stroke (compression) is an indicator of the technical condition (wear) of the cylinder-piston group and valves. The torque on the crankshaft of the engine determines the traction force on the wheels: the more it is, the better dynamics car acceleration. It is equal to the product of the force and the shoulder (Fig. 3) and is measured in N m (Newton per meter), previously in kgf.m (kilogram-force per meter).

Torque increases with growth: displacement. Therefore, engines that require significant torque have a large volume; pressure of burning gases in the cylinders, which is limited by detonation (explosive combustion of a gasoline-air mixture, accompanied by a characteristic ringing sound. It is erroneously called "knocking piston pins") or an increase in loads in diesel engines. The engine develops the maximum torque at certain speeds (see below), they, together with its value, are indicated in the technical documentation. Engine power - a value showing what work it does per unit of time, measured in kW (previously in horsepower) One horsepower (hp) is approximately equal to 0.74 kW Power is equal to torque multiplied by angular velocity crankshaft (rpm multiplied by a certain factor). Engines more power manufacturers receive an increase in: the working volume, which, in turn, leads to an increase in the dimensions of the engine and the limitation of the permissible maximum speed due to the significant inertia forces of the increased parts; revolutions of the crankshaft, the number of which is limited by inertial forces and increased wear of parts. A high-speed engine of the same power (ceteris paribus - engine design, manufacturing technology, materials used, etc.) with a low-speed engine has a shorter service life, since on average for the same run its crankshaft will make more revs; pressure in the cylinder by increasing the compression ratio or pressurizing air through a turbo or mechanical superchargers. To use supercharging, the compression ratio is forcedly reduced to prevent detonation (for gasoline engines) and reduce the rigidity of work (increased loads in the cylinder-piston group of a diesel engine, accompanied by excessive noise) (for diesel engines). Supercharging allows, for example, to save power with a smaller displacement. Rated power - the power guaranteed by the manufacturer at full fuel supply at a certain speed. It is she, and not the maximum power, that is indicated in the technical documentation for the engine. Specific fuel consumption is the amount of fuel consumed by the engine per 1 kW of developed power in one hour. It is an indicator of the perfection of the engine design: the lower the flow rate, the more efficiently the energy of the fuel burned in the cylinders is used. With the same design parameters, different engines indicators such as power, torque and specific consumption fuel may vary. This is due to such features as the number of valves per cylinder, valve timing, etc. Therefore, to evaluate the operation of the engine at different speeds, characteristics are used - the dependence of its performance on operating modes. Characteristics are determined empirically on special stands, since theoretically they are calculated only approximately. As a rule, the technical documentation for the car contains the external speed characteristics of the engine (Fig. 4), which determine the dependence of power, torque and specific fuel consumption on the number of revolutions of the crankshaft at full fuel supply. They give an idea of the maximum performance of the engine.

Engine indicators (simplified) change according to the following reasons. With an increase in the number of revolutions of the crankshaft, the torque increases due to the fact that more fuel enters the cylinders. Approximately at medium speeds, it reaches its maximum, and then begins to decline. This is due to the fact that with an increase in the speed of rotation of the crankshaft, inertial forces, friction forces, aerodynamic drag inlet pipelines, worsening the filling of cylinders fresh charge fuel-air mixture, etc. A rapid increase in engine torque indicates good vehicle acceleration dynamics due to an intensive increase in traction on the wheels. The longer the moment is at its maximum and does not decrease, the better. Such an engine is more adapted to changing road conditions and less likely to have to change gears. Power grows with torque and even when it starts to decline, continues to increase due to the increase in speed. After reaching the maximum, the power begins to decrease for the same reason that the torque decreases. Turnovers slightly higher than the maximum power are limited by control devices, since in this mode a significant part of the fuel is consumed not for useful work, but to overcome the forces of inertia and friction in the engine. The maximum power determines top speed car. In this mode, the car does not accelerate and the engine only works to overcome the forces of resistance to movement - air resistance, rolling resistance, etc. The value of the specific fuel consumption also varies depending on the crankshaft speed, which can be seen in the characteristic (see Fig. 4). The specific fuel consumption should be as long as possible close to the minimum; this indicates good engine efficiency. The minimum specific consumption, as a rule, is achieved just below the average speed, at which the car is mainly operated when driving in the city. The dotted line on the graph shows more optimal engine performance.

Today I propose to dive a little into the world of pistons and machine oil and figure out what types of engines are and are used on our favorite, beloved cars.

In principle, even any humanitarian, in the worst sense of the word, will immediately answer this question: diesel and gasoline. Well, someone else will add electric. However, in reality there are many more of these engines. Briefly about each.

1. Diesel engine

He's just a diesel. A reciprocating internal combustion engine that works because the fuel (diesel fuel) ignites in its bowels (or rather, in the cylinders) during a sharp compression, as a result of which the temperature rises and the atomized fuel ignites. The idea of igniting fuel by compression belonged to Sadi Carnot. And in practice, it was embodied by Rudolf Diesel, who patented several engine options from 1892 to 1897. Diesel is used not only in cars, but also on ships, railway locomotives.

Diesel engines are available in two-stroke and four-stroke versions. I spoke about the reasons for the popularity and advantages of diesel engines in a separate article and I will not repeat myself, but will move on to another engine

2. Gasoline engine

Here, the ignition of the fuel-air mixture in the cylinders also occurs at elevated pressure, but from the electric spark that the candle gives. All gasoline engines are divided into carburetor and injection. The difference is in the way the fuel-air mixture is formed. In addition, gasoline engines are classified by the number and arrangement of cylinders, by the method of cooling, the type of lubrication, and many other characteristics. It is not possible to describe all these options. Therefore, I turn to the next type of automobile engine.

3. Rotary piston internal combustion engine

In its current form Created by the inventor Freude in 1957. However, Freude started from the work of another inventor, Felix Wankel, who received a patent for a rotary engine back in 1936. Freude, by and large, simply perfected this creation. By the way, for some time both inventors worked together. The engine does not have a gas distribution mechanism.

The principle is this: a triangular-shaped rotor rotates in an 8-shaped (this shape is also called an epitrochoid) chamber. The chamber has an inlet and an outlet. Due to the shape of the rotor, in one revolution it goes through three cycles at once (mixture intake, compression and ignition, power stroke and exhaust gases), like a six-cylinder engine.

The mixture is ignited by an electric spark. And the combustion chamber is formed between the edge of the rotor and the wall of the chamber. It did not receive much distribution (by the way, it was even produced by VAZ - the VAZ-21018 model had a rotary engine). By the way, VAZ produced as many as 50 cars. However, during the tests, ALL motors broke down (either hands from experience, or a place there) and the model was discontinued. But after some time, the project was nevertheless saved and the production of VAZ-411 and VAZ-413 was launched, which were widely used by cops and gays.

By the way, on these cars with engines of 120 and 140 “horses”, people in uniform easily overtook and overtook foreign cars of those times. But then the spies (and who else ?!) curtailed this project and the Zhiguli with "wankels" (the second name for the rotary engine) ceased to be produced. Although now the VAZ designers seem to be fooling around with these motors again.

The main disadvantage rotary engine is the problem of the fragility of the seal between the rotor and the chamber, as well as with the lubrication system. Everything is connected here. Due to the design and operation of the engine, oil has to be injected into the manifold. In short, such an engine does not shine at all with environmental friendliness and economy. In addition, the rotary engine runs only on gasoline. This engine is currently used in Mazda car RX-8.

4. Hybrid engine

Or rather, it would be more correct to say, a hybrid system, since a hybrid is not a single engine, but an ingenious combination of an internal combustion engine and an electric motor. Incidentally, the principle hybrid engine has been known since 1910 and has been widely used on ... railway transport, and more specifically, on diesel locomotives.

In the late 1990s, people started talking about electric vehicles. But most motorists perceived this idea as an eccentricity of fighters for the environment, preferring to drive on proven, affordable and relatively cheap (our country of that period is not taken into account) gasoline and diesel fuel. Today, almost all leading automotive companies world release hybrid models cars.

Although they are more complicated in the device and crammed with electronics to the very “I can’t”, nevertheless, they have a number of advantages:

Reduce fuel consumption by almost half

Significantly reduce noise and harmful emissions into the atmosphere (for cruising speed the car practically does not use gasoline due to the operation of the traction electric motor)

Allows you to accelerate the car much faster from a standstill and make good acceleration on the move

Many experts and businessmen are inclined to believe that hybrid engine systems are a transitional stage to pure electric vehicles. Frankly, intellectually, I understand the benefits of an electric car. But in my heart I perceive him as a rubber woman or a trance, which is even worse. It looks like it, but not quite the same.

By the way, electric motors were used before, back in the middle of the 20th century, but not quite on cars, but on various loaders or mini-cars for recreational driving, not to mention trolleybuses and trams.

author: Andrey Abin, for the site