The power system is designed for. Vehicle fuel system

It is a whole complex of devices. The main task is not just the supply of fuel to the injection nozzles, but also the supply of fuel under high pressure. Pressure is required for high-precision metered injection into the cylinder's combustion chamber. The diesel power system performs the following most important functions:

• dosage of a strictly defined amount of fuel, taking into account the load on the engine in one or another mode of its operation;
• efficient fuel injection in a given period of time with a certain intensity;
• atomization and the most uniform distribution of fuel over the volume of the combustion chamber in the cylinders of a diesel internal combustion engine;
• pre-filtration of fuel before supplying fuel to the power supply pumps and injection nozzles;

Read in this article

Features of diesel fuel

Most of the requirements for the power supply system of a diesel engine are put forward taking into account the fact that diesel fuel has a number of specific features. Fuel of this kind is a mixture of kerosene and gas oil solar fractions. Diesel fuel is obtained after distillation of gasoline is realized from oil.

Diesel fuel has a number of properties, the main of which is considered to be the self-igniting index, which is estimated by the cetane number. The types of diesel fuel on sale have cetane number at around 45-50. For modern diesel units The best fuel is a fuel with a high cetane number.

The power supply system of a diesel internal combustion engine ensures the supply of well-purified diesel fuel to the cylinders, the injection pump compresses the fuel to high pressure, and the nozzle delivers it, sprayed to the smallest particles, into the combustion chamber. Atomized diesel fuel is mixed with hot (700–900 ° C) air, which is heated to such a temperature from high compression in the cylinders (3–5 MPa) and ignites spontaneously.

Please note that the working mixture in a diesel engine is not ignited by a separate device, but ignites independently from contact with heated air under pressure. This feature strongly distinguishes the diesel internal combustion engine from gasoline counterparts.

Diesel fuel also has a higher density compared to gasoline, and also has better lubricity. An equally important characteristic is the viscosity, pour point and purity of diesel fuel. The pour point allows fuel to be divided into three basic grades of fuel:.

Diagram of a diesel engine power supply system

The diesel engine power system consists of the following basic elements:

1. fuel tank;
2. coarse filters for diesel fuel;
3. filters fine cleaning fuel;
4. fuel priming pump;
5. high pressure fuel pump (high pressure fuel pump);
6. injection nozzles;
7. low pressure pipeline;
8. high pressure line;
9. air filter;

Electric pumps, exhaust gases, particulate filters, mufflers, etc. become additional elements. The power supply system for diesel internal combustion engines is usually divided into two groups of fuel equipment:

• diesel equipment for fuel supply (fuel supply);
• diesel equipment for air supply (air supply);

The fuel supply equipment can have a different device, but today the most common system is the split type. In such a system, the high pressure fuel pump (TNVD) and injectors are implemented as separate devices. Fuel is supplied to the diesel engine via high and low pressure lines.

Diesel fuel is stored, filtered and supplied to the high pressure fuel pump at low pressure through the low pressure line. In the high-pressure line, the injection pump raises the pressure in the system to supply and inject a strictly defined amount of fuel into the working combustion chamber of a diesel engine at a given moment.

The diesel power system contains two pumps at once:

• fuel priming pump;
• high pressure fuel pump;

The fuel priming pump supplies fuel from fuel tank, pumps fuel through a coarse and fine filter. The pressure generated by the fuel priming pump allows fuel to flow through the low pressure fuel line to the high pressure fuel pump.

The high pressure fuel pump implements the high pressure fuel supply to the injectors. The supply takes place in accordance with the operating order of the cylinders of the diesel engine. The high pressure fuel pump has a certain number of identical sections. Each of these sections of the injection pump corresponds to a specific cylinder of the diesel engine.

There is also a power supply system for diesel engines of an undivided type and is used on diesel two-stroke engines... In such a system, the high pressure fuel pump and the injector are combined in a single device called a pump injector.

These motors run hard and noisy and have a short service life. There are no high pressure fuel lines in the design of their power system. The specified type of internal combustion engine is not widespread.

Let's go back to the mass construction of the diesel engine. Diesel injectors are located in the cylinder head () of the diesel engine. Their main task is to accurately atomize the fuel in the engine combustion chamber. The fuel priming pump supplies a large amount of fuel to the injection pump. The resulting excess fuel and air entering the fuel supply system are returned to the fuel tank through special pipelines called drain lines.

Injection diesel injectors are of two types:

• closed type diesel nozzle;
• open type diesel injector;

Four-stroke diesel motors preferably closed-type nozzles are obtained. In such devices, the nozzles of the nozzles, which are a hole, are closed with a special shut-off needle.

It turns out that the internal cavity located inside the nozzle body of the nozzles communicates with the combustion chamber only during the opening of the nozzle and at the moment of injection of diesel fuel.

The key element in the nozzle design is the atomizer. The sprayer receives from one to a whole group of nozzle holes. It is these holes that form the fuel flame at the time of injection. The shape of the torch depends on their number and location, as well as throughput nozzles.

Turbodiesel power system

Diesel fuel system airing: signs of malfunction and diagnostics. How to find an air leak on your own, ways to solve the problem.

The design of a high pressure diesel fuel pump, potential malfunctions, circuit and principle of operation using the example of a fuel supply system.

Ministry of Education of the Russian Federation

Saint Petersburg State University

service and economy

Motor vehicles

"Design and operation of the gasoline engine power supply system"

Completed by a 3rd year student

Specialty 100.101

Ivanov V.I.

St. Petersburg

Introduction

1. Work of engines on a working mixture

2. Power system carburetor engine

3. Design and operation of the carburetor engine power supply system

4. Power supply system of a petrol engine with fuel injection

5. Safety precautions

List of used literature

Introduction

The power system is a set of devices and devices that supply fuel and air to the engine cylinders and exhaust exhaust gases from the cylinders.

The power system is used to prepare the combustible mixture required for the engine to operate.

Combustible is called a mixture of fuel and air in certain proportions.

1.Working engines on a working mixture

Working is the mixture of fuel, air and exhaust gases formed in the cylinders when the engine is running.

Depending on the place and method of preparing the combustible mixture, car engines may have various systems power supply (fig. 1).

Figure: 1. Types of power supply systems for motors classified according to various criteria

The power system with the preparation of a combustible mixture in a special device - a carburetor - is used in gasoline engines, which are called carburetor engines. To prepare a combustible mixture in the carburetor, the atomization method is used. With this method, droplets of gasoline, falling from the sprayer into the air flow in the mixing chamber of the carburetor moving at a speed of 50 ... 150 m / s, grind, evaporate and, mixing with air, form a combustible mixture. The resulting combustible mixture enters the engine cylinders.

The fuel injection system is also used in gasoline engines. To prepare the combustible mixture, finely atomized fuel is injected under pressure from the nozzles into the rapidly moving air stream in the intake manifold. Fuel is mixed with air, and the resulting combustible mixture enters the engine cylinders.

The power supply system with preparation of a combustible mixture directly in the engine cylinders is used both in diesel engines and in gasoline engines. The preparation of the combustible mixture takes place inside the engine cylinders by injecting finely atomized fuel from the injectors under pressure into the air compressed in the cylinders. At the same time, if in diesel engines self-ignition of the formed working mixture occurs from compression, then in gasoline engines the working mixture in the cylinders is ignited forcibly from the spark plugs. The fuel injection system provides better filling of the engine cylinders with a combustible mixture and better cleaning of exhaust gases. In this case, fuel injection allows an increase in the compression ratio and maximum power at gasoline engines, reduce fuel consumption and reduce the toxicity of exhaust gases. However, fuel injection power systems are more complex in design and maintenance in operation.

2. Power supply system of the carburetor engine

Fuel. For gasoline engines of cars, the fuel is gasoline of various brands - A-80, AI-93, AI-95, AI-98, where the letter A means automobile; I - method for determining the octane number of gasoline (research); 93, 95, 98 - octane number, characterizing the resistance of gasoline against detonation. The higher the octane number, the higher the compression ratio of the engine can be.

Detonation - the process of combustion of the working mixture with the explosion of its individual volumes in the engine cylinders with a flame propagation speed of up to 3000 m / s, while with normal combustion of the working mixture, the flame propagation speed is 30 ... 40 m / s. Combustion on detonation becomes explosive. The shock wave propagates in the engine cylinders at supersonic speed. Gas pressure rises sharply and engine performance and efficiency deteriorate. There are loud knocks in the engine, black smoke from the muffler, and the engine overheats. In this case, the parts of the crank mechanism quickly wear out and the valve heads are burned.

To increase the antiknock properties, a TPP antiknock agent, tetraethyl lead, is added to gasoline. Such gasolines are called leaded, they have a distinctive designation and color - AI-93-ethyl (orange-red) and AI-98-ethyl ( of blue color). Leaded gasolines are very poisonous, and care must be taken when handling them - do not use for washing hands and parts, do not suck in by mouth when pouring, etc.

The use of leaded gasoline for cars in large cities is prohibited.

3. Design and operation of the carburetor engine power supply system

The power supply system of the car engine consists of a fuel tank, a fuel pump, air filter, carburetor, fuel lines, inlet and outlet lines, muffler pipes, main and additional mufflers (Fig. 2).

Fuel from tank 6 is supplied by pump 7 through fuel lines 5 to the carburetor 4. Through the air filter 1 air enters the carburetor. The fuel mixture prepared in the carburetor is supplied to the engine cylinders through the intake manifold 2. Exhaust gases are discharged from the engine cylinders to the environment through the exhaust pipe 3, pipe 8 mufflers, main 10 and additional 9 mufflers.

Figure: 2. Engine power supply system:

1 - air filter; 2,3 - pipelines; 4 - carburetor; 5 - fuel line; 6 - tank; 7 - pump; 8 - trumpet; 9, 10 - mufflers

A fine fuel filter is often installed in the engine power system. The fuel tank is connected by a hose to a separator (a special device) for condensing gasoline vapors, and a drain line with a carburetor. Check valves are installed on the separator hose and drain line. One valve prevents fuel from the tank from being drained through the carburetor when the car rolls over, and the other valve connects the inner cavity of the tank to the atmosphere. Fuel is fed into the system with a return drain of its part from the carburetor (through a calibrated hole) into the fuel tank, which ensures constant fuel circulation in the system. Continuous fuel circulation eliminates air pockets in the system, improves its performance and contributes to additional engine cooling.

Fuel tank serves to store the fuel supply required for a certain vehicle mileage. On cars, welded, stamped steel fuel tanks with a lead coating to protect against corrosion, or plastic are used. A tank filled with gasoline provides a vehicle mileage of 350 ... 400 km.

The fuel tank (fig. 3) is welded from two trough-shaped halves 1. In the upper part, the tank has a filler neck, consisting of a receiving 13 and bulk 10 pipes with a seal 8 and rubber connecting hose 11. The filler neck is closed with a threaded sealed plug 6 with gasket 7. At the bottom of the tank there is a drain hole with a screw plug 14. The amount of fuel in the tank is controlled by a pointer, a sensor 3 which is installed inside the tank. Fuel is taken from the tank through the fuel intake pipe 2, which has a mesh filter, and through a hose 4 and fuel line 5 enters the fuel pump. The connection of the inner cavity of the tank with the environment and its ventilation are carried out through the air 12 and ventilation 9 tube.

Figure: 3. Fuel tank:

1 - half of the tank; 2, 9, 12 - tubes; 3 - sensor; 4, 11 - hoses; 5 - fuel line; 6, 14 - traffic jams; 7 - gasket; 8 - sealant; 10, 13 - pipes

In the fuel tanks of cars, there are often special baffles to increase rigidity and reduce fuel fluctuations when driving inside. In addition, in the lower part of the tank there is an anti-drain device made in the form of a glass with a diameter of 150 and a height of 80 mm. This device is designed to exclude interruptions in the operation of the engine and its stopping during sudden start-off or sudden braking, as well as when the vehicle is moving on high speeds cornering.

The shape of the fuel tank is largely dependent on its placement on the vehicle. The tank can be located under the floor of the body, in the trunk, under the rear and behind back seat, i.e. in places more protected from impacts in collisions. The fuel tank is attached to the vehicle body.

Fuel pump serves for fuel supply from the fuel tank to the carburetor. Self-regulating, diaphragm-type fuel pumps are installed on car engines.

IN fuel pump (fig. 4) between the top 7 (with a cover 9) and bottom 1 a block of diaphragms is installed in the housing 3, which is connected to the stem 11. The rod is covered by the forked end of the balancer 15 lever 16 pump drive. There is a spring on the stem 2 block of diaphragms. In the upper part of the pump housing there is a suction 10 and 4 discharge valves. The pump is driven by a pusher from the drive shaft eccentric oil pump... Under the influence of the eccentric, the pusher presses on the upper part of the lever 16, and the balancer 15 through the stem 11 moves the diaphragm unit 3 down. In this case, the spring 2 shrinks. The volume of the cavity above the block of diaphragms increases, and the fuel, under the action of vacuum from the tank, enters the pump through the suction pipe 8, strainer b and suction valve 10. The pump discharge valve is then closed. Up the diaphragm block moves under the action of a spring 2, when the balancer 15 does not hold the stem 11.

Figure: 4. Fuel pump:

1,7 - parts of the body; 2, 13 - springs; 3 - block of diaphragms; 4, 10 - valves; five, 8 - branch pipes; 6 - filter; 9 - cap; 11 - stock; 12, 16 - levers; 14 - eccentric; 15 - balancer

The fuel pressure opens the discharge valve 4, and the fuel through the discharge pipe 5 enters the carburetor. The suction valve is then closed. When the carburetor float chamber is full, the float shut-off needle will close off fuel to the carburetor. In this case, the block of diaphragms of the fuel pump will remain in the lower position, and the lever 16 with the balancer will move without load. Lever arm 12 with spring 13 serves for manual pumping of fuel into the carburetor before starting the engine. It affects the balancer 15 through the eccentric 14. The pump self-regulates - at low fuel consumption, the stroke of the diaphragm unit is underutilized, and the stroke of the mechanical fuel pumping lever with the balancer will be partially idle. The fuel pump is installed on a special tide on the engine block and is attached to it with two pins.

Fine fuel filter cleans the fuel entering the carburetor from mechanical impurities. Fuel cleaning is necessary so that the channels and jets of the carburetor, which have small sections, are not clogged. The fine fuel filter can be made non-separable (Fig. 5, and). Paper filter element 3 such a filter is located in the housing 2 with a lid, which are made of plastic and welded together with currents high frequency or ultrasonic welding. Fuel enters the filter from the pump through the pipe 4, passes through the filter element, is cleaned in it and through the nozzle 1 enters the carburetor.

Collapsible filters are also used for fine fuel purification.

Dismountable filter (fig. 5, b) consists of a body 2, sump 5 and filter element 3. The filter element is made of a brass mesh wound in two layers on an aluminum alloy glass, which has ribs and holes for fuel passage on the side surface. The mesh on the glass is held by a spring, which is put on the outside of the filter element. Filter element 3 is located inside the sump 5 and is compressed by a spring 6 to the filter housing through the gasket.

Figure: 5. Fuel filters:

and - non-separable; b - collapsible; 1, 4 - branch pipes; 2 - body; 3 –Filter element; 5 - sump; 6 - spring

When cleaning, the fuel first enters the sump, where the largest particles of impurities are deposited, and then it is cleaned by passing through the mesh into the filter element cup.

Fuel filters are usually installed between the fuel pump and the carburetor.

Air filter cleans the air entering the carburetor from dust and other impurities. The dust contains the smallest crystals of hard quartz, which, settling on the lubricating surfaces of the rubbing engine parts, cause their intense wear.

Mainly dry type air filters with replaceable paper or cardboard filter elements are used on car engines.

Air filter (fig. 6, and) consists of a body 1, cover 7 and filter element 3. Stamped steel body with spigot 10 intake of cold air from the engine compartment, branch pipe 2 intake of warm air from the air intake on the exhaust pipe, the exhaust manifold of the crankcase ventilation system and the axle of the cover. The filter housing is installed on the carburetor and is attached to it on four pins with self-locking nuts. Filter housing cover - steel, stamped, has a baffle 8, depending on the location of which seasonal adjustment of the temperature of the air entering the engine is provided. In summer, the filter cover is installed so that the partition 8 closes the branch pipe 2, and the engine receives cold air... In winter, the lid is set in a position in which the partition 8 closes the branch pipe 10, and warm air enters the engine. The tightness of the connection between the cover and the filter housing is ensured by a rubber gasket 6. Filter element 3 has a cylindrical shape. It consists of a 5 pleated cardboard filter and a pre-cleaner plate 4 made of non-woven synthetic material (synthetic wool layer). The pre-cleaner cover acts as a preliminary air purification element and increases the dust holding capacity of the filter. The air entering the filter first passes through the pre-cleaner plate and then through the cardboard filter element.

The air filter shown in fig. 6, b, has a thermostat. Housing 22 and the filter cover 7 - steel, stamped. The housing contains a cardboard filter element 19 with an outer layer of synthetic wool for preliminary air purification, increasing the dust holding capacity of the filter. The filter element is tightly pressed against the body by a cover that is attached to the body on a hairpin 20 nut and four latches 21. The stud is installed in a bracket welded to the body. The tightness of the cover with the body is ensured by a gasket 18. The filter housing is mounted on the carburetor and is attached to it through a plate 23 and rubber gasket 24 on four studs with self-locking nuts. The body has a branch pipe below for suction of crankcase gases, and on the side - a branch pipe 16 air intake, on which the thermostat is fixed with a tightening bolt 13. The thermostat provides a constant supply to the air filter heated to a temperature of 25 ... 35 ° C air. It has a plastic body with a tube 12 cold air supply and branch pipe 11 with hose 14 warm air supply. There is a damper inside the thermostat 25 driven by a thermal power element 15, which allows you to automatically maintain the required temperature of the air entering the air filter.

Figure: 6. Air filters:

about - without thermostat; b - with a thermostat; 1, 22 - housing; 2, 10, 11, 12, 16 - branch pipes; 3, 19 - filter elements; 4 - pre-cleaner cover; 5- filter; 6, 18, 24- gaskets; 7, 17- covers; 8- partition; 9 – axis; 13 - thermostat; 14 - hose; 15 - thermal power element; 20 - hairpin; 21 - latch; 23 - plate; 25 - damper

At air temperatures below 25 ° C, the damper closes the branch pipe 12 cold air supply, and enters the filter through the pipe 11 warm air from the area of \u200b\u200bthe engine exhaust pipe. At an air temperature of more than 35 ° C, the damper closes the branch pipe 11, and through the pipe 12 cold air enters from the engine compartment. The intermediate positions of the thermostat flap provide a mixture of warm and cold air, which contributes to better mixture formation, more complete combustion of the mixture and, as a result, a decrease in the toxicity of exhaust gases and a decrease in fuel consumption.

A dry type air filter with a replaceable paper filter element is shown in fig. 7. The filter consists of a body 6, cover 5 and filter paper 7 of cylindrical shape. The plastic filter housing has a pipe 8, through which it is connected with a rubber corrugated hose to the carburetor air intake. A special device is installed in the plastic cover of the filter housing 4 with flap 3, depending on the location of which seasonal adjustment of the temperature of the air entering the engine is provided. In summer, the damper is set to the lower position, blocking the pipe 1, and cold air enters the engine. In winter, the damper is set to the upper position, blocking the pipe 2, and warm air enters the engine.

Carburetor serves to prepare a combustible mixture (gasoline with air) in quantities and composition corresponding to all engine operating modes.

The carburetor is installed on the intake manifold of the engine.

The simplest carburetor (Fig. 8) consists of a float chamber 8 with float 9 and needle valve 10 and mixing chamber in which the diffuser is located 3, spray 4 with nozzle 7 and throttle valve 5.

The float chamber contains gasoline required for the preparation of a combustible mixture. A float with a needle valve maintains gasoline in the float chamber and the sprayer at a Constant level - 1 ... 1.5 mm below the end of the sprayer. This level ensures good suction of gasoline and eliminates fuel leakage from the spray nozzle when the engine is not running.

If the gasoline level drops, then the float with the valve is lowered and gasoline enters the float chamber. If the gasoline level reaches normal, the float floats up and the valve closes the access of gasoline to the float chamber.

The sprayer supplies gasoline to the center of the carburetor mixing chamber. The atomizer is a tube that enters the mixing chamber and communicates with the float chamber through a nozzle.

The jet passes a certain amount of gasoline, which enters the spray nozzle. The jet is a plug with a calibrated hole.

The mixing chamber is used to mix gasoline with air. The mixing chamber is a pipe, one end of which is connected to the intake manifold of the engine, and the other to the air filter.

The diffuser serves to increase the air flow rate in the center of the mixing chamber. It creates a vacuum at the end of the atomizer. The diffuser is a tube that is tapered inside.

The throttle valve regulates the amount of fuel mixture flowing from the carburetor into the engine cylinders.

The carburetor works as follows.

At the inlet strokes to the mixing chamber 6 air enters. In the diffuser 3 the air speed increases, and at the end of the nozzle 4 a vacuum is formed. As a result, gasoline is sucked out of the sprayer and mixed with air. The resulting combustible mixture enters the cylinders 12 engine through the intake manifold P.

When the engine is running, the driver of the car controls the throttle valve 5. Control is carried out from the cab using a pedal. The throttle valve is set to different positions depending on the required engine load. According to the regulation throttle different amounts of the combustible mixture enter the engine cylinders.

Figure: 8. Diagram of the device and operation of the simplest carburetor:

1 - fuel line; 2 - air connection hole; 3 - diffuser; 4 - spray; 5 - damper; 6 - mixing chamber; 7 - jet; 8 - float chamber; 9 - float; 10 - valve; 11 - pipeline; 12 - engine cylinder

As a result, the engine develops different power levels and the car moves at different speeds.

The car engine has the following five modes of operation: start, idle, medium (partial) load, a sharp transition from medium load to full and full load.

At each operating mode, a combustible mixture must be supplied to the engine cylinders in a different quantity and of a different quality. Only in this case the engine will operate stably and have the best performance and efficiency.

At all the indicated engine operating modes, the simplest carburetor cannot provide the engine with a combustible mixture required quality and in the required quantity. Therefore, the simplest carburetor is equipped with additional devices that ensure the normal operation of the engine in all modes.

The main additional devices of the carburetor include a starting device (air damper), a system idle move, main metering device, booster pump and economizer.

The starting device ensures that the fuel from the sprayer is supplied in the amount necessary to start the engine.

Idling system allows the engine to run without load at low rpm crankshaft engine.

The main dosing device ensures that the engine runs at partial (medium) engine loads.

The accelerator pump is used for automatic enrichment of the combustible mixture during a sharp transition from partial load to full load in order to quickly increase engine power,

The economizer serves for automatic enrichment of the combustible mixture at full engine load.

Construction and work additional devices carburetor are discussed below.

On car engines, two-chamber balanced carburetors with a falling mixture flow are used. Carburetors have two mixing chambers, which are switched on in sequence - first, the main chamber (primary), and with an increase in engine load, an additional chamber (secondary). This allows you to increase engine power as a result of better dosage and distribution of the combustible mixture over the engine cylinders. The flow of the combustible mixture in the carburetor chambers moves from top to bottom, which improves the filling of the cylinders with the mixture. The carburetor float chamber is balanced (unbalanced), since it is connected to the atmosphere through an air filter. This ensures the preparation of a combustible mixture by the carburetors, which does not depend in its composition on the degree of clogging of the air filter. The float chamber is located in front of the carburetors (in the direction of the vehicle), which excludes re-enrichment of the combustible mixture during braking and increases the fuel level in the spray nozzles when driving uphill to enrich the combustible mixture and increase engine power.

A car's carburetor usually has three main parts: a body, a cover, and a throttle body. They contain all the systems and devices of the carburetor, which ensure the preparation of a combustible mixture under various operating conditions of the engine and reduce the toxicity of exhaust gases.

Consider the design of a modern carburetor (Fig. 9). In the case 43 and lid 44 placed a float chamber 16 with float 24 and needle valve 17, primary I and secondary II mixing chambers, as well as systems and devices for preparing a combustible mixture.

Figure: 9. Carburetor diagram:

I, II - mixing chambers; 1 - pneumatic element; 2 - stock; 3 - channel; 4, 10, 17, 23, 40 - valves; 5, 22, 25, 26, 28, 38 - fuel jets; 6, 7, 14, 15 - air jets; 8, 30, 32 - dampers; 9, 11, 12, 13 – sprayers; 16 - float chamber; 18, 20, 36, 37 - branch pipes; 19 - filter; 21 - economizer; 24 - float; 27, 39 - tubes; 29, 33 – holes; 31 - gap; 34 - heating block; 35 - screw; 41 - diaphragm; 42 - lever arm; 43 - body; 44 - cap

The carburetor is equipped with: a heating unit 34, through which the coolant of the engine cooling system circulates; crankcase suction system, including a branch pipe 36 and a calibrated hole; a backflow system for part of the fuel from the carburetor into the fuel tank, including a branch pipe 18 and a calibrated hole. It has a secondary camera lock. The interlock prevents the throttle valve of the secondary chamber from opening in any mode of engine operation if the choke valve is not fully open. This excludes the operation of the secondary chamber when the engine is cold. Fuel enters the carburetor through a pipe 20 and filter 19, and through the pipe 37 the carburetor is connected to a vacuum ignition regulator.

The main metering system prepares a lean fuel mixture (1 kg of gasoline accounts for up to 16.5 kg of air) when the engine is running at medium (partial) loads. The prepared mixture in different amounts in composition is close to economical in the entire range of average loads, the value of which is up to 85% of the full engine load. Only with such preparation of the combustible mixture by the carburetor does the engine work most economically.

The main metering systems of the primary and secondary chambers include the main fuel jets 38 and 28, emulsion wells with emulsion tubes 39 and 27, main air jets 6 and 14, sprayers 9 and 12. When opening the throttle 32 the primary chamber is fuel from the float chamber 16 through the main fuel jet 38 enters the emulsion well. In it, the fuel is mixed with air coming out of the holes of the emulsion tube. 39, into which air enters through the main air jet 6. Emulsion through a spray bottle 9 enters the small and large diffusers of the primary chamber and mixes with the air passing through the diffusers, where a combustible mixture is formed. The main metering system of the secondary chamber works in a similar way to the main metering system of the primary chamber. Throttle valve 30 the secondary chamber is mechanically connected to the throttle valve 32 the primary chamber in such a way that it begins to open when the throttle valve of the primary chamber is open 2/3 of its value.

The throttle valves have a mechanical (cable) drive from the control pedal located in the passenger compartment. The amount of the combustible mixture entering the engine cylinders is regulated by the opening of the throttle valves. At medium loads, the primary carburetor chamber operates mainly, providing engine operation over a wide range of partial loads.

The starting device provides for the preparation of a rich combustible mixture (less than 13 kg of air per 1 kg of gasoline) when starting a cold engine. The fuel mixture is supplied to the engine cylinders in large quantities so that even with a cold engine, light fractions of gasoline evaporate in the amount necessary to start the engine.

The starting device consists of an air damper 8 and associated pneumatic element 1. Air damper through the stem 2 connected to the diaphragm of the pneumatic element and is under the influence of the return spring. When starting a cold engine, the throttle 32 the primary chamber opens slightly. In this case, the return spring, acting on the lever of the air damper axis, keeps it in the closed position. The amount of air entering the primary chamber decreases, the vacuum in the diffusers increases, and fuel flowing out of the atomizer 9, provides the formation of a combustible mixture. At the first flashes and subsequent engine idling, vacuum from under the throttle valve 32 transmitted over the channel 3 into pneumatic element 1. Its diaphragm flexes and the stem 2 opens the air damper, providing the required amount of air, and the air damper return spring is stretched. Therefore, when starting a cold engine and warming it up, the air damper is automatically set to a position that excludes excessive enrichment or depletion of the combustible mixture. As the engine warms up, the choke opens fully after cable drive the control handle of the starting device located under the dashboard.

The idle system prepares an enriched fuel mixture (up to 13 kg of air per 1 kg of gasoline). When the engine is idling, a small amount of the enriched mixture enters the engine cylinders to keep the engine running stably.

The idling system includes: a fuel channel originating from the emulsion well of the primary chamber; fuel jet 5; air jet 7; emulsion channel; screw quality (composition) mixture 35; mixture amount screw; outlet 33. Idle throttle 32 ajar. In this case, the transition gap 31 the idle system is located above the top edge of the throttle valve. The air damper is fully open. Under the influence of vacuum, the fuel from the emulsion well through the channel enters the idle fuel nozzle 5, where it mixes with air supplied through the idle air nozzle 7. The resulting emulsion is mixed with air passing through the transition gap 31, and goes under the throttle 32 through the hole 33. Slit 31, located above the throttle valve, provides the flow of emulsion under the throttle valve for a smooth transition of the engine from idle to partial loads. When the engine is idling, the quality of the mixture is regulated by the screw 35, and the amount - by the screw of the amount of the mixture, when screwed in, the throttle valve opens slightly. When the ignition is turned off, it turns off solenoid valve 4. Its needle, under the action of a spring, locks the fuel jet 5 and excludes the idling system when the ignition is off. The idling system has a primary carburetor chamber, and the secondary chamber is equipped with a transition system.

The transitional system smoothly turns on the secondary carburetor chamber at small openings of its throttle valve.

Secondary chamber transition system includes a fuel jet 26 with tube, air jet 15 and emulsion channel with outlets 29. At the start of opening the throttle 30 in front of the holes 29 a large vacuum is created. As a result, through the fuel jet 26 fuel enters, and through the air jet 15 - air. The resulting emulsion is fed through the channel to the outlet openings 29, through them goes under the throttle 30 and enriches the combustible mixture. As a result, a smooth engagement of the secondary carburetor chamber is ensured.

The accelerator pump enriches the fuel mixture when the engine changes abruptly from medium load to full load (overtaking, driving after stopping before a traffic light, etc.).

The booster pump increases the engine throttle response, i.e. the ability to quickly develop the greatest power.

Accelerating pump - diaphragm, mechanically driven. Fuel enters the pump from the float chamber through the inlet ball valve 40, When the throttle valve of the primary chamber of the carburetor is suddenly opened, a special cam mounted on the valve axis acts on the lever 42 pump drive that presses on the diaphragm 41. The diaphragm, overcoming the force of the return spring, bends and pushes the fuel through the channel, the discharge valve 10 and spray 11 Accelerator pump into the primary and secondary chambers, while enriching the combustible mixture. The inlet valve of the accelerating pump is closed at this moment.

Econostat serves for additional enrichment of the combustible mixture at full engine load. The econostat is an economizing device. Econostat includes a fuel jet 25 with tube, fuel line and sprayer 13. The econostat is equipped with a secondary carburetor chamber. It comes into operation at full throttle valves and maximum engine speed. In this case, fuel from the float chamber enters through the fuel jet 25 and the fuel line to the atomizer 13 econostat and from it to the secondary chamber of the carburetor, enriching the combustible mixture.

The power mode economizer excludes changes in the degree of enrichment of the combustible mixture due to vacuum pulsations under the carburetor throttle valves. The process of suction of the combustible mixture into the engine cylinders is intermittent, and its pulsation (vacuum pulsation) increases with a decrease in the crankshaft speed. In this case, vacuum pulsation is transmitted to the main dosing system, reducing its effectiveness of automatic regulation of the composition of the combustible mixture. Economizer 21 power modes - diaphragm type. It is connected to the main metering system of the primary chamber by a fuel channel in which a fuel jet is installed. 22 economizer, and through a ball valve 23 - with float chamber 16. The economizer is also connected by an air duct with a throttle space. With a slight opening of the throttle 32 ball valve 23 closed, as the economizer diaphragm is held by vacuum under the throttle valve. With a significant opening of the throttle valve, the vacuum decreases, the economizer diaphragm with the needle deflects under the action of the spring and opens the valve 23. Fuel from the float chamber passes through the open valve, the fuel jet 22 and the fuel channel to the emulsion well with a tube 39. It is added to the fuel leaving the main fuel jet of the primary chamber and enters through the atomizer 9 into the primary chamber of the carburetor, leveling the composition of the combustible mixture.

The Forced Idle Economizer reduces fuel consumption and reduces exhaust emissions when the engine is forced to idle.

Forced idle economizer consists of a limit switch installed on the idle mixture amount adjusting screw, an electromagnetic shut-off valve 4 and electronic unit management. In forced idle mode (engine braking, driving downhill, when shifting gears), the throttle valves of the primary and secondary chambers of the carburetor are closed, the throttle control pedal is released. In this case, the carburetor limit switch is closed, the solenoid valve 4 turns off, its needle locks the idle fuel jet 5, and the fuel supply to the idle system is stopped.

Figure: 10. Inlet and outlet piping:

1, 5 - pipelines; 2, 4,6,7- flanges; 3 - a tube; 8 - hairpin

Inlet and outlet piping provide the supply of a combustible mixture to the cylinders and the removal of exhaust gases. The intake manifold serves to uniformly supply the fuel mixture from the carburetor to the engine cylinders.

An intake manifold made of an aluminum alloy is used on car engines. For better evaporation of the fuel deposited on the walls, the pipeline has a heater (jacket) in which the engine cooling system fluid circulates. The exhaust pipe is designed to remove exhaust gases from the engine cylinders. Exhaust pipes made of cast iron are installed on car engines. Inlet pipeline 5 motor (fig. 10) has flanges 4 and 6. Flange 4 designed to fit the carburetor, and the flange 6 - for connection to the cylinder head.

Exhaust pipeline 1 has flanges 2 and 7 Flange 2 serves for fastening the exhaust pipe of the mufflers, and the flange 7 - for communication with the cylinder head. The inlet and outlet pipes are fastened with studs 8 to the cylinder head through metal-asbestos gaskets, ensuring the tightness of their connection.

Muffler reduces noise when exhaust gases are discharged from engine cylinders. On passenger cars usually two mufflers (main and additional) are installed, due to which double expansion of the exhaust gases and a more efficient reduction of exhaust noise are provided. Both mufflers have the same design and differ only in size and materials used for them.

Figure: 11. Silencers:

1 - main muffler; 2, 3, 7, 8 - pipes; 4, 6 - partitions; 5 - additional muffler

All parts of the main muffler 1 (Fig. 11) are made of corrosion-resistant steel, and the parts of the additional muffler 5 are made of carbon steel. Mufflers are non-separable, welded from two stamped halves. There are pipes inside the mufflers 3 and 7 with a lot of holes as well as partitions 4 and 6. Exhaust gases coming from the intake pipes 8 into mufflers, first into additional 5, and then in the main 1, they expand, change direction and, passing through the holes in the pipes, sharply reduce their speed. This leads to a decrease in the noise of the exhaust gas discharge through the pipe 2. Mufflers reduce the noise of exhaust gases emitted into the environment by up to 78 dB. The loss of engine power to overcome the resistance of the mufflers is approximately 4%. The mufflers on the car are attached to the floor of the body with rubber parts.

4. Power supply system of a gasoline engine with fuel injection

The fuel-injected engine power system includes the fuel tank, fuel pump, fuel filter, air filter, injectors, fuel pressure regulator, engine fuel lines, intake and exhaust lines, fuel lines, muffler intake pipes, resonators and muffler.

In fig. 12 shows a diagram of a part of the fuel injection engine power system, which supplies fuel and air to the cylinders and prepares the combustible mixture necessary for all engine operating modes.

Fuel from tank 6 through the fuel filter 8 and the fuel lines are supplied by the pump 7 into the fuel line 2 engine that is installed on the intake manifold 4 and in which the nozzles are fixed 3.

Figure: 12. Scheme of the power supply system of the engine with fuel injection:

1 - damper; 2 - engine fuel line; 3 - nozzles; 4 - inlet pipeline; 5 - pressure regulator; 6 - tank; 7 - pump; 8 - filter

Clean air enters the intake manifold from the air filter, the amount of which is regulated by the air throttle valve 1. Regulator 5 with the engine running maintains the fuel pressure in the fuel line 2 engine and injectors 3 within 0.28 ... 0.33 MPa. During the intake stroke, the air flow moving with high speed in the intake manifold 4, under pressure from nozzles 3 finely atomized fuel is injected. Fuel is mixed with air, and the resulting combustible mixture from the intake manifold enters the engine cylinders in accordance with the engine operating order.

Exhaust gases are discharged from the engine cylinders through the exhaust pipe, resonators and muffler to the environment.

Consider the structure and operation of the devices of the fuel injection engine power system.

Fuel pump (Fig. 13) is a centrifugal roller pump driven by an electric motor, which is mounted together with the pump in one sealed casing.

The centrifugal roller pump consists of a stator 3, the inner surface of which is slightly offset relative to the axis of the armature 8 electric motor, cylindrical cage 16, an electric motor connected to the armature, and rollers 17, located in the separator.

A separator with rollers is located between the base 2 and the pump cover 5.

When the pump is running, fuel flows through the union 1 and channel 18 to the rotating separator 16, carried by rollers and through output channels 6 is fed into the cavity of the electric motor and then through the valve 11 and fitting 12 into the fuel line that supplies fuel to the fuel filter.

Figure: 13. Fuel pump:

1, 12 – fittings; 2 - base; 3 - stator; 4, 11 - valves; 5 - cap; 6, 18 - channels; 7, 9 - housing; 8 - anchor; 10 - collector; 13 - brush; 14 - clutch; 15 - shaft; 16 - separator; 17 - roller

The fuel entering the pump, passing through the electric motor, cools it. Check valve 11 eliminates the drain of fuel from the fuel line and the formation of air jams after the fuel pump is turned off. Safety valve 4 limits the fuel pressure generated by the pump when it rises above the permissible value - 0.45 ... 0.6 MPa. The fuel pump turns on when the ignition is turned on. The pump flow is 130 l / h.

Engine fuel line (fig. 14) serves to supply fuel to the injectors. It is common to four injectors. One end of the fuel line 4 screwed in fitting 3 for supplying fuel from the pump, and a regulator is attached at the other end 5 fuel pressure associated with the receiver and the fuel tank. In the fuel line of the engine, nozzles are fixed at one end 2, which are fixed at the other end in the inlet pipeline 1. The ends of the nozzles are sealed with rubber O-rings. Fuel line 4 fastened with two bolts to the intake manifold.

Fuel pressure control (Fig. 15) maintains the pressure in the fuel line and injectors of the operating engine within 0.28 ... 0.33 MPa, which is necessary to prepare a combustible mixture of the required quality in all engine operating modes. The pressure regulator consists of a body 1 and covers 3, between which the diaphragm is fixed 4 sec valve 2. The internal cavity of the regulator is divided by a diaphragm into two cavities - vacuum and fuel.

Figure: 14. Engine fuel line:

1 - inlet pipeline; 2 - nozzle; 3 - fitting; 4 - fuel line; 5 - pressure regulator

Figure: 15. Fuel pressure regulator:

and - the valve is closed; 6 - the valve is open; 1 - case; 2 - valve; 3 - cover; 4 - diaphragm

The vacuum cavity is in the lid 3 regulator and is connected to the receiver, and the fuel cavity is in the housing 1 regulator and connected to the fuel tank.

When the air throttle valve 1 is closed (see Fig. 12), the vacuum in the receiver increases, the regulator valve opens at a lower fuel pressure and bypasses excess fuel through the fuel return line to the fuel tank 6. In this case, the fuel pressure in the fuel line 2 the engine goes down. When the air throttle valve is opened, the vacuum in the receiver decreases, the regulator valve opens at a higher fuel pressure. As a result, the fuel pressure in the engine fuel line rises.

Nozzle (fig. 16) is a solenoid valve. The nozzle is designed to inject a metered amount of fuel required to prepare a combustible mixture at various engine operating modes. The dosage of the amount of fuel depends on the duration of the electrical impulse entering the coil of the injector electromagnet. Fuel injection by the injector is synchronized with the position of the piston in the engine cylinder.

Figure: 16. Nozzle;

1 - nozzle; 2 - needle; 3, 9 - hulls; 4 - coil; 5 - filter; 6- cap; 7- spring; 8 - core

The nozzle consists of a body 3, cover 6, coils 4 electromagnet, core 8 electromagnet, needle 2 shut-off valve, body 9 spray nozzle 1 sprayer and filter 5,

When the engine is running, fuel under pressure enters the injector through the filter 5 and passes to the shut-off valve, which is in the closed state under the action of the spring 7.

When an electrical impulse enters the coil winding 4 the electromagnet creates a magnetic field that attracts the core 8 and with him an igloo 2 shut-off valve. In this case, the hole in the housing 9 The nozzle opens and pressurized fuel is sprayed out in atomized form.

After the termination of the flow of an electric pulse into the winding of the coil of the electromagnet, the magnetic field disappears, and under the action of the spring 7, the core 8 electromagnet and needle 2 the shut-off valve returns to its original position. Hole in the housing 9 the nozzle closes and fuel injection from the nozzle stops.

5. Safety precautions

Safety precautions when caring for the power system must be observed. So, when using leaded gasoline, you need to be especially careful when handling it, as this gasoline is very poisonous.

Do not allow gasoline to come into contact with your skin when refueling, inspecting, and cleaning the fuel system. If leaded gasoline gets on your skin, wash it with clean kerosene, and wash your hands with soap and warm water and wipe dry.

Do not use leaded gasoline for washing parts and hands, and do not suck gasoline through the hose with your mouth when pouring and blow through the fuel lines with your mouth.

Do not allow the engine to run in a closed room that is not equipped with special ventilation. This can cause people in the room to be poisoned by the exhaust gases.

During all maintenance work on the power supply system, it is imperative to observe the fire safety rules.

List of used literature

1. Sarbaev V.I. Car maintenance and repair. - Rostov n / a: "Phoenix", 2004.

2. Vakhlamov V.K. Automotive technology. - M .: "Academy", 2004.

3. Barashkov I.V. Brigade organization of vehicle maintenance and repair. - M .: Transport, 1988.

In order for any engine to work like a clock, all its parts must be in perfect condition. Moreover, the systems that ensure its functioning cannot fail. Failure of at least one of them will lead to unstable operation of the device. In the worst case scenario, this can lead to an accident.

One of the most important ICE maintenance systems is the power supply system. It supplies fuel to the inside, where it is ignited and converted into mechanical energy.

There are many ICEs. During the development of the automotive industry, scientists came up with many designs, each of which represented another round in the development of the industry. Very few of them went into mass production. Nevertheless, over almost a hundred years of continuous evolution, the following basic designs have been identified:

• diesel,
• injection,
• carburetor.

Each of them has its own advantages and disadvantages, moreover, the internal combustion engine power system is different in each design.

Diesel

Diesel internal combustion engine power system

When fuel enters the combustion chamber, the diesel fuel supply system creates the right pressure... Also her range of tasks includes:

• fuel dosage;
• injecting the required amount of fuel fluid for a certain time period;
• spraying and distribution;
• filtration of fuel fluid before entering the pump.

To better understand the structure of the power supply system of a diesel engine, you need to know what diesel fuel itself is. Its structure is a mixture of kerosene and diesel fuel after special processing. These substances are formed when gasoline is released from oil. In fact, these are leftovers from the main production that automakers have learned to use effectively.

Diesel fuel circulating in the internal combustion engine system has the following parameters:

• octane number,
• viscosity,
• pour point,
• purity.

Diesel fuel in the internal combustion engine system is divided into three grades, depending on the parameters described above:

• summer,
• winter,
• arctic.

In fact, the classification can occur according to several criteria and be much deeper. Nevertheless, if we take into account the generally accepted standard, then it will be just that.

Now let's take a closer look at the structure iCE systems, it consists of the following elements:

• fuel tank,
• pump,
• high pressure pump,
• nozzles,
• pipeline with low and high pressure,
• exhaust gas pipeline,
• air filter,
• muffler.

All these elements make up common system power supply, which ensure stable engine operation. If we take into account the design, then it is divided into two subsystems: the one that provides air supply, and the other that implements the fuel supply.

The fuel circulates through two lines.One has low pressure. It stores and filters fuel fluid, and then goes to the high pressure pump.

Fuel enters the combustion chamber directly through a high-pressure line. It is through it that at a certain moment the fuel substance is injected into the chamber.

Important! The pump has two filters. One provides coarse cleaning and the other fine.

The injection pump supplies power to the injectors. Its operating mode directly depends on the operating mode of the engine cylinders. The fuel pump always has an even number of sections. Moreover, their number directly depends on the number of cylinders. More precisely, one parameter corresponds to another.

The injectors are installed in the cylinder heads. It is they who supply the combustion chamber by spraying the fuel substance inside. But there is one small caveat. The fact is that the pump delivers much more fuel than is needed. Simply put, the amount of food is too large. In addition, air gets inside, which can interfere with all work.

Attention! To avoid malfunctions, there is a drainage pipeline. It is he who is responsible for ensuring that the air is discharged back into the fuel tank.

The injectors in the structure responsible for powering the internal combustion engine can be closed and open. In the first case, the holes are closed due to the shut-off needle. To make this possible, the internal cavity of the parts is connected to the combustion chamber. That's just happening this is when injecting liquid.

The main element in the nozzle design is the atomizer. It can have one or several nozzle holes. Thanks to them, the internal combustion engine power structure creates a kind of torch.

To increase power, a turbine is added to the internal combustion engine power system. It allows the car to gain momentum much faster. By the way, earlier such devices were installed only on racing and trucks... But modern technologies made it possible not only to make the product several times cheaper, but also significantly reduced the dimensions of the structure.

The turbine is capable of supplying air through the internal combustion engine power system inside the cylinders. The turbocharger is responsible for boosting. He uses waste gases for his work. Air enters the combustion chamber under a pressure of 0.14 to 0.21 MPa.

The role of the turbocharger is to fill the cylinders with the volume of air required for operation. If we talk about power characteristics, then this element in the ICE power supply system allows achieving an increase of up to 25-30 percent.

Important! The turbine increases the load on the parts.

Possible malfunctions

Despite a number of visible advantages of the internal combustion engine power system, it still has a number of significant disadvantages, which can result in a number of malfunctions, the most common are:

1. The engine does not want to start. Typically, such a malfunction indicates a problem with the fuel priming pump. But other options are also possible, for example, improper condition of injectors, ignition system, plunger pairs or discharge valve.
2. Uneven engine operation indicates a problem with individual injectors. A leak in the valve can lead to the same results. Also, during the operation of the car, there may be a weakening of the plunger fastening.
3. The engine does not deliver the power declared by the manufacturer. Most often, this defect is associated with the fuel priming pump. Nozzles and nozzle breakage can lead to the same result.
4. Knocking when the engine is running, smoke from under the hood... This happens when the fuel is fed into the system too early, or it has a cetane number that does not correspond to the standards declared by manufacturers.
5. Soft claps. The reason for such a malfunction in the internal combustion engine power system lies in the air leak.
6. Clutch knocking. This happens if the parts of the device are too worn out and there is a strong shrinkage of the springs.

As you can see, there can be more than enough malfunctions in the internal combustion engine system. That is why, in order to determine exactly what the matter is, it is necessary to carry out a comprehensive diagnosis. Moreover, some manipulations require special equipment.

Almost all of the faults described above can be corrected. Complete replacement internal combustion engine power systems are needed only in extreme cases. Moreover, even a simple adjustment can completely restore the functionality of the automotive unit.

Methods for the restoration of a diesel engine

To restore the operation of the device, it is necessary to clean the blow-out windows from carbon deposits, if present there. Check if there is enough lubricant inside the coupling. If the quantity lubricant minimum - add it to an acceptable amount

Most often, the engine knocks and smokes in those cases when the fuel you fill in has a low cetane number. Fortunately, the recipe for getting out of this situation is pretty simple. It is enough to change the fuel fluid to one in which this indicator will be more than 40.

Injection engine

Injection engine power supply system

Injection power systems began to be used at the beginning of the 80s of the last century. They replaced carburetor designs. In a device working with an injector, each cylinder has its own injector.

The injectors are attached to the fuel rail. Inside this structure, the fuel fluid is under pressure, which is provided by the pump. The longer the period of time the injector is open, the more fuel is injected inside.

The period that the injectors are in the open position is controlled by the electronic controller. This is a kind of control unit with a clearly built control algorithm. It matches the opening moment with the sensor readings. The electronic filling does not stop for a second. This ensures a stable fuel supply.

Important! A special sensor is responsible for the air flow. It is on the basis of the cycles that the cylinder filling is calculated.

The throttle load is sensed by a separate sensor. More precisely, he makes the calculations. Then it sends the data to the controller, where the verification takes place and adjustments are made if necessary.

If we talk about the fuel injection system of the internal combustion engine, then it almost completely works due to the indicators of many sensors. The most important sensors are those responsible for the following parameters:

• temperature,
• crankshaft position,
• oxygen concentration,
• control of detonation during ignition.

Moreover, these are only basic sensors. In fact, there are much more of them in the internal combustion engine power system.

Malfunctions

As mentioned above, the internal combustion engine power system is almost entirely based on the operation of sensors. The greatest harm can be caused by a breakdown of the sensor responsible for crankshaft... If this happens, then you will not even reach the garage. The same will happen if the fuel pump fails.

Important! If you are going on a long trip, take a spare gas pump with you. This is the second heart of your car.

If we talk about the safest malfunctions of the internal combustion engine power system, then this is, of course, a breakdown of the phase sensor. This defect will cause the least damage to the car. In addition, repairs will take a minimum of time.

Important! Phase sensor malfunction is indicated unstable work nozzles. This is usually evidenced by a sharp jump in gasoline consumption.

Carburetor engines

Supply system

The first carbureted engine was created in the last century by Gottlieb Daimler. The power supply system of a carburetor engine is not particularly complex and consists of such elements as:

• fuel tank,
• pump,
• fuel line,
• filters,
• carburetor.

The capacity of the tank is usually about 40-80 liters in cars with carburetor ICE power systems. This device is in most cases mounted at the rear of the machine for greater safety.

From the fuel tank, gasoline flows into the carburetor. A fuel line connects these two devices. It goes under the bottom vehicle... During transportation, the fuel passes through several filters. The pump is responsible for the flow.

Malfunctions

The design is the oldest of the three. Despite this, its simplicity helps to significantly reduce the risk of any breakdown. Unfortunately, not a single internal combustion engine power supply system, including a carburetor one, is immune from malfunctions; the following defects can occur with it:

• impoverishment fuel mixture,
• fuel cut-off,
• gasoline leak.

Leaks are easily seen with the naked eye. Stopping the fuel supply will prevent the car from moving. If the carburetor sneezes, then the fuel mixture is lean.

Outcome

Over the years of development of the automotive industry, many ICE power systems have been created. The first was the carburetor. She is the most simple and unpretentious. Its successors are diesel and injection.

The main unit of any car is its engine, which is used as an engine internal combustion (ICE). Depending on the fuel used, the types of engine power systems also differ, which are very important for the normal operation of the engine.

Types of engine power systems

Depending on the fuel fluid used, engines, and, consequently, power systems can be divided into three main types:

• gasoline;
• diesel;
• working on gaseous fuels.

There are other types, but their use is very small.

In some cases, the classification of power systems is not made by the type of fuel, but by the method of preparation and supply of the combustible mixture to the combustion chamber. In this case, the following types are distinguished:

• carburetor (ejector);
• with forced injection (injection).

Carburetor system

This system is used for gasoline engines. It is based on the formation of an air-fuel mixture due to the vacuum created by the movement of the piston. The air is sucked in passively, mixed in the diffuser with the atomized fuel and enters the cylinder, where it is ignited with a spark plug. Such mechanical method has a number of disadvantages, for example - high fuel consumption and design complexity.

Forced injection

This system became a logical continuation of the first and replaced it. The work is based on the forced supply of a metered amount of fuel through the nozzle. Depending on the number of injectors, injection types of engine power supply systems are with distributed (the number of injectors and cylinders is equal) and centralized (one injector) injection.

The diesel engine has its own distinctive feature: fuel is fed through the nozzle directly into the cylinder, where air is sucked in separately. Ignition occurs due to high pressurecreated by the piston, so no plugs are used.

Regardless of which system is used on your car, the main malfunctions of the engine power system are usually associated either with insufficient fuel supply or with a violation of its supply regulation. Therefore, to ensure reliable operation, it is necessary to carry out maintenance... For these purposes, all the necessary details and expendable materials you can purchase online in the store site by favorable prices... Save time and money with us!

The vehicle's fuel system is used to prepare the fuel mixture. It consists of two elements: fuel and air. The engine power system performs several tasks at once: cleaning the mixture elements, receiving the mixture and supplying it to the engine elements. The composition of the combustible mixture differs depending on the vehicle power system used.

Types of power systems

There are the following types of engine power systems, which differ in the place of formation of the mixture:

1. inside the engine cylinders;
2. outside the engine cylinders.

Fuel system when a mixture is formed outside the cylinder, it is divided into:

• fuel system with carburetor
• using one injector (mono injection)
• injector

Purpose and composition of the fuel mixture

For smooth operation of a car engine, a certain fuel mixture is required. It consists of air and fuel mixed in a certain proportion. Each of these mixtures is characterized by the amount of air per unit of fuel (gasoline).

The enriched mixture is characterized by the presence of 13-15 parts of air per part of the fuel. This mixture is supplied at medium loads.

A rich mixture contains less than 13 parts of air. It is used for heavy loads. There is an increased consumption of gasoline.

A normal mixture has 15 parts of air per part of fuel.
The lean mixture contains 15-17 parts of air and is used at medium loads. Provides economical fuel consumption. A poor mixture contains more than 17 parts of air.

General structure of the power system

The engine power system has the following main parts:

• fuel tank. Serves for storing fuel, contains a pump for pumping fuel and sometimes a filter. Has a compact size
• fuel line. This device supplies fuel to a special mixing device. Consists of various hoses and tubes
• mixture formation device. Designed to obtain a fuel mixture and supply to the engine. Such devices can be injection system, mono injection, carburetor
• control unit (for injectors). Consists of an electronic unit that controls the operation of the mixing system and signals when malfunctions occur
• fuel pump. Required for the flow of fuel into the fuel line
• filters for cleaning. Necessary to obtain pure components of the mixture

Carburetor fuel supply system

This system is distinguished by the fact that mixture formation occurs in special device - carburetor. From it, the mixture enters the engine in the desired concentration. The engine power system device contains the following elements: a fuel tank, fuel cleaning filters, a pump, an air filter, two pipelines: inlet and outlet, and a carburetor.

The scheme of the engine power supply system is implemented as follows. The tank contains fuel that will be used for feeding to. It enters the carburetor through the fuel line. The feeding process can be realized with a pump or naturally by gravity.

In order for the fuel supply to flow into the carburetor chamber by gravity, then it (the carburetor) must be placed below the fuel tank. Such a scheme cannot always be implemented in a car. But the use of a pump makes it possible not to depend on the position of the tank relative to the carburetor.

The fuel filter cleans the fuel. Thanks to it, mechanical particles and water are removed from the fuel. Air enters the carburetor chamber through a special air filter that removes dust particles from it. The chamber mixes the two purified components of the mixture. Getting into the carburetor, fuel enters the float chamber. And then it is sent to the mixing chamber, where it is combined with air. Through the throttle valve, the mixture enters intake manifold... From here it goes to the cylinders.

After exhausting the mixture, gases from the cylinders are removed using the exhaust manifold. Then they are sent from the manifold to the muffler, which suppresses their noise. From there, they enter the atmosphere.

Details about the injection system

At the end of the last century, carburetor power systems began to be intensively replaced by new systems operating on injectors. And for a reason. This arrangement of the engine power system had a number of advantages: less dependence on the properties of the environment, economical and reliable operation, and less toxic emissions. But they have a drawback - it is a high sensitivity to the quality of gasoline. If this is not observed, then some system elements may malfunction.

"Injector" is translated from English as an injector. A single-point (single-injection) scheme of the engine power system looks like this: fuel is supplied to the injector. The electronic unit sends signals to it, and the nozzle opens at the right time. The fuel is directed to the mixing chamber. Then everything happens as in a carburetor system: a mixture is formed. It then passes the intake valve and enters the engine cylinders.

The device of the engine power supply system, organized using injectors, is as follows. This system is characterized by the presence of several nozzles. These devices receive signals from a special electronic unit and open. All these injectors are connected to each other via a fuel line. There is always fuel in it. Excess fuel is removed through the fuel return line back to the tank.

The electric pump supplies fuel to the rail, where overpressure is generated. The control unit sends a signal to the injectors, and they open. Fuel is injected into the intake manifold. Air, passing through the throttle assembly, enters the same place. The resulting mixture enters the engine. The amount of mixture required is adjusted by opening the throttle valve. As soon as the injection stroke ends, the injectors close again and the fuel supply stops.

The electronic unit is a kind of "brain" element of the system. This complex mechanism processes incoming signals from various sensors. This is how all devices of the fuel system are controlled. Such a circuit of the engine power system allows the driver to find out about malfunctions in time, since the control unit signals them using a special lamp and error codes. These codes allow technicians to quickly identify problems. To do this, they just need to connect an external diagnostic device that can recognize the problems that have arisen and name them.