Fuel injection
The era of the carburetor is replaced by the era of the injection engine, the power system is based on the fuel injection. Its main elements are: an electric fuel pump (located, as a rule, in the fuel tank), nozzles (or nozzle), the control unit of the DVS (the so-called "brains").
The principle of operation of this nutrition system is reduced to spraying fuel through the pressure under pressure generated by the fuel pump. The quality of the mixture varies depending on the engine operation mode and is controlled by the control unit.
An important component of such a system is a nozzle. The typology of injection engines is based on the number of injectors used and their location. 
So, experts tend to allocate the following injector options:
- with distributed injection;
- with the central injection.
The distributed injection system involves the use of nozzles by the number of engine cylinders, where each cylinder serves its own nozzle involved in the preparation of a combustible mixture. The central injection system has only one nozzle to all cylinders located in the collector.
Features of diesel engine
As if the principle of action is worth the principle on which the diesel engine power system is based. Here, the fuel is injected directly into the cylinders in the sprayed form, where the process of mixing (mixing with air) is occurring, followed by ignition from the compression of a combustible mixture with a piston.
Depending on the fuel injection method, Diesel force aggregate Submitted by three main options:
- with direct injection;
- with a whirlpool injection;
- with a pre-commercial injection.
The dramatic and pre-commercial variants involve fuel injection into a special preliminary cylinder chamber, where it is partially flammable, and then moves to the main chamber or the cylinder itself. Here fuel, mixing with air, finally burns. The immediate injection involves the delivery of fuel immediately into the combustion chamber, followed by mixing it with air, etc. 
Another feature, which is distinguished by the diesel engine power system, is the principle of combustion of a combustible mixture. This does not happen from the spark plug (like gasoline engine), and on the pressure generated by the piston of the cylinder, that is, by self-ignition. In other words, in this case there is no need to apply spark plugs.
but cold Engine It will not be able to ensure the proper level of temperature required to ignite the mixture. And the use of incandescent candles will allow the necessary heating of combustion chambers.
Food system operation modes
Depending on the purpose and road conditions, the driver can apply various modes of motion. They are consistent with certain modes of operation of the power system, each of which is inherent in the fuel and air mixture of special quality.
- The composition of the mixture will be rich in the start of the cold engine. At the same time, air consumption is minimal. In this mode, the possibility of movement is categorically eliminated. Otherwise, this will lead to increased consumption of fuel and wear of the force aggregate details.
- The composition of the mixture will be enriched when using the mode " idle move", Which is used when moving" rolling "or the operation of the engine of the engine in a heated state.
- The composition of the mixture will be depleted when moving with partial loads (for example, on a flat road with average speed on increased gear).
- The composition of the mixture will be enriched in full load mode when the car is moving at high speed.
- The composition of the mixture will be enriched, approximate to the rich, when driving under sharp acceleration (for example, when overtaking).
The choice of the operating conditions of the power system, thus, should be justified by the need to move in a certain mode.
Malfunctions and service
In the process of operation vehicle The fuel system of the car is experiencing loads leading to its unstable functioning or failure. The most common are the following malfunctions.
Insufficient receipt (or lack of admission) fuel in engine cylinders
Poor-quality fuel, long service life, impact ambient They lead to contamination and clogging of fuel pipelines, tanks, filters (air and fuel) and the technological holes of the combustible mixture, as well as a breakdown of the fuel pump. The system will require a repair that will be in a timely replacement of filtering elements, periodic (once every two or three years), clean the fuel tank, carburetor or injector nozzles and replacing the pump.
Loss of power of the economy
Fuel system malfunction in this case Determined by the violation of the quality adjustment and the amount of combustible mixture coming into the cylinders. The elimination of malfunction is associated with the need to diagnose the combustible mixture preparation device.
Fuel leak
Fuel leakage - the phenomenon is very dangerous and categorically not allowed. This malfunction is included in the "List of faults ...", with which the movement of the car is prohibited. Causes of problems are losing in the loss of tightness with nodes and fuel system units. The elimination of malfunction is either in replacing the damaged elements of the system, or in tightening fasteners of fuel pipelines.
Thus, the power system is an important element The MODE of the modern car is responsible for timely and uninterrupted fuel supply to the power unit.
It is a whole range of devices. The main task is not just the supply of fuel to injection injectors, and also the supply of fuel under high pressure. Pressure is necessary for high-precision dosage injection into the cylinder combustion chamber. The diesel power system performs the following major functions:
- dosing a strictly defined amount of fuel based on the engine load in one or another mode of its operation;
- effective fuel injection at a predetermined period of time with a certain intensity;
- spraying and the most uniform distribution of fuel in terms of the combustion chamber in diesel engine cylinders;
- pre-filtering fuel before fuel supply in power supply pumps and injection nozzles;
Most of the requirements for the diesel engine power supply system put forward with the fact that diesel fuel It has a number of specific features. This kind of fuel is a mixture of kerosene and gas-free solar fractions. Diesel fuel is obtained after gasoline outflow is implemented from oil.
Diesel fuel has a number of properties, the main of which is considered to be the indicator of self-flammability, which is estimated by the cetane number. The types of diesel fuel presented on sale have a cetane number at a mark of 45-50. For modern diesel units, the best fuel is fuel with a large indicator of the cetane number.
The diesel engine power supply system provides the supply of well-purified diesel fuel to the cylinders, the pump compresses fuel to high pressure, and the nozzle supplies it in the combustion chamber sprayed on the smallest particles. The sprayed diesel fuel mixes with a hot (700-900 ° C) air, which is heated to such a temperature from high compression in the cylinders (3-5 MPa) and self-propagates.
Please note the working mixture in the diesel engine is not set in price by a separate device, and flammable independently from a heated air contact. This feature is greatly distinguished by diesel engine from gasoline analogues.
Diesel fuel has a higher density relatively with gasoline, and also has the best lubricity. No less an important characteristic There is viscosity, frosted temperature and purity of diesel fuel. The temperature of the frozen allows you to divide the fuel into three basic fuel varieties :.
Diesel Diesel Food System Device Scheme
The diesel engine power system consists of the following basic elements:
- fuel tank;
- filters of coarse cleaning of diesel fuel;
- filters thin cleaning fuel;
- fuel pumping pump;
- high pressure fuel pump (TNVD);
- injector nozzles;
- pipeline low pressure;
- high pressure hut;
- air filter;
Additional elements partially becomes the electric pump, the release of exhaust gases, saw filters, silencers, etc. The diesel engine power supply system is commonly divided into two groups of fuel equipment:
- diesel equipment for the occasion of fuel (fuel-feed);
- diesel apparatus for air supply (air supploring);
Fuel supply equipment may have various deviceBut today the system of separated type is most common. In such a system, the high pressure fuel pump (TNVD) and the nozzles are implemented as individual devices. Fuel is served in a diesel engine on high and low pressure highways.
Diesel fuel is stored, filtered and fed to an electric pressure under low pressure by means of a low pressure highway. The high-pressure high-pressure highway raises pressure in the system for carrying out the supply and injection of a strictly defined amount of fuel into the working chamber of the combustion of the diesel engine at a specified moment.
Two pumps are present in the diesel power system:
- fuel pumping pump;
- high pressure fuel pump;
The fuel pumping pump provides fuel supply from the fuel tank, pumps fuel through the coarse and thin cleaning filter. The pressure that creates the fuel-pumping pump allows the supply of fuel to the low pressure fuel supply to the high pressure fuel pump.
TNVD sells fuel supply to high pressure nozzles. The feed occurs in accordance with the order of operation of the diesel engine cylinders. Fuel pump High pressure has a certain number of identical sections. Each of these sections of the TNVD corresponds to a specific diesel engine cylinder.
There is also a system for the nutrition of the diesel engines of non-dedicated type and is applied on diesel two-stroke engines. In such a system, the high-pressure fuel pump and the nozzle are combined in one device called the pump-nozzle.
These motors work hard and noisy, have a short service life. In the design of their power system there are no high-pressure fuel lines. Specified type of DVS It does not have much spread.
Let's return to the mass design of the diesel engine. Diesel nozzles are located in the head of the cylinder block () diesel engine. Their main task becomes accurate spraying of fuel in the engine combustion chamber. The fuel-blowing pump delivers a large amount of fuel to the pump. The resulting excess of fuel and the air penetrating the fuel feed system is returned to the fuel tank using special pipelines, which are called drainage.
Injector diesel nozzles are two types:
- closed diesel nozzle;
- open diesel nozzle;
Four-stroke diesel motors predominantly get closed-type nozzles. In such devices, nozzle nozzles, which are a hole, are closed with a special locking needle.
It turns out that the inner cavity, located inside the housing of the injectors, is communicated with the combustion chamber only during the opening of the nozzle and at the time of the injection of diesel fuel.
A key element in the injector design is a sprayer. The sprayer receives from one to the whole group of nozzle holes. It is these holes that form a fuel torch at the time of injection. The form of a torch depends on their quantity and location, as well as the throughput of the nozzle.
Turbodizel power supply system
Encrying of the diesel fuel system: signs of malfunction and diagnostics. How to independently find the air suction site, ways to solve the problem. 
In order for any engine to work as a clock in perfect condition should be all its details. Moreover, the system that ensures its functioning cannot fail. The failure of at least one of them will lead to an unstable functioning of the device. With the worst development of events, this can lead to an accident.
One of the most important DVS maintenance systems is the power system. It supplies fuel inside, where it flammifies and turns into mechanical energy.
DVS There is a huge set. During the development of automotive industry, many structures were invented, each of which was the next round of the development of the Industry. Very few of them went into mass production. Nevertheless, such basic constructions were allocated for almost a hundred years of continuous evolution:
- diesel
- injector,
- carburetor.
Each of them has its advantages and disadvantages, moreover, the power supply system in each design is different.
Diesel
Food system diesel engine
When fuel enters the combustion chamber, the power supply system for diesel engine creates the desired pressure. Also in its range tasks include:
- dosage of fuel;
- injection of the desired amount of fuel fluid for a certain time period;
- spraying and distribution;
- filtering the fuel fluid before entering the pump.
To better understand the device of the diesel engine power system, you need to know what a diesel fuel is in itself. By its structure, this is a mixture of kerosene and diesel fuel after special processing. These substances are formed when gasoline is distinguished from oil. In fact, these are the remnants from the main production that the automotors learned to effectively use.
Diesel fuel circulating in the DVS system has such parameters:
- octane number,
- viscosity,
- frozen temperature,
- purity.
Diesel fuel in the KVS system is divided into three varieties depending on the parameters described above:
- summer
- winter
- arctic.
In fact, the classification can occur in several criteria and be much deeper. Nevertheless, if you take into account the generally accepted standard, then it will be exactly the same.
Now consider in more detail the structure systems of DVSIt consists of such elements:
- fuel tank
- pump
- high pressure pump
- nozzles,
- low and high pressure pipelines,
- exhaust gas pipeline
- air filter,
- muffler.
All these elements make up a common nutrition system that provide stable work Engine. If you take into account the design, it is divided into two subsystems: the one that provides the air supply, and the other that implements the flow of fuel.
The fuel circulates in two highways.One has low pressure. It stores and filtered fuel fluid, after which it is sent to the pump with high pressure.
Directly into the combustion chamber, fuel falls through high pressure hut. It was through it that at a certain point passes the injection of the fuel substance inside the chamber.
Important! There are two filters in the pump. One provides gross purification, and the second is thin.
TNVD carries out the nozzles. His work mode directly depends on the mode of operation of the engine cylinders. In the fuel pump always aware number of sections. Moreover, their number directly depends on the number of cylinders. More precisely, one parameter corresponds to another.
Nozzles are installed in cylinder heads. It is they who carry out the combustion chamber by spraying the fuel substance inside. But there is one small nuance. The fact is that the pump gives fuel much more than necessary. Simply put, the amount of nutrition is too large. In addition, the air, which can interfere with all the work.
Attention! So that there are no failures in the work there is a drainage pipeline. It is he who is responsible for getting the air back into the fuel tank.
Nozzles in the design that is responsible for the power of the DVS can be closed and open. In the first case, the closure of the holes occurs due to the shut-off needle. So that it becomes possible - the inner cavity of the parts is connected to the combustion chamber. But only happens it is when injected liquid.
The main element in the injector design is the sprayer. It can have both one and several nozzle holes. Thanks to them, the power structure of the DVS creates a peculiar torch.
To increase power to the power system, the DVS is added to the turbine. It allows the car to gain momentum significantly faster. By the way, earlier, such devices were installed only on racing and trucks. But modern technologies Allowed not only to make a product at times cheaper, but also significantly reduced design dimensions.
The turbine is capable of supplying air through the power supply system inside the cylinders. For the supervision of the turbocharger. For his work, it uses exhaust gases. Inside the combustion chamber air falls under pressure from 0.14 to 0.21 MPa.
The role of the turbocharger is to fill the cylinders necessary for operation of the air. If we talk about the powerful characteristics, this element in the power system of the DVS allows you to achieve an increase of up to 25-30 percent.
Important! The turbine increases the load on the details.
Possible malfunctions
Despite a number of visible advantages of the power supply system, it still has a number of significant flaws that can pour into a number of faults, the most common can be ranked:
- The engine does not want to run. Usually, such a malfunction indicates problems in the fuel pumping pump. But other options are also possible, for example, inadequate nozzles, ignition systems, plunger pairs or discharge valve.
- Uneven engine work Indicates problems with separate nozzles. Exactness in the valve can lead to the same results. Also during the operation of the car may be weakened by the attachment of the plunger.
- The engine does not give the stated power producer. Most often, this defect is associated with everything with a fuel-blowing pump. Nozzles and nozzles can lead to the same result.
- A knock when working a motor, smoke from under the hood. This happens when the fuel is supplied to the inside of the system too early, or it has a cetane number, not corresponding to the manufacturers declared by manufacturers.
- Non-cotton. The reason for such a malfunction in the power system of the engine lifting in the air seats.
- Knock coupling. This happens if the details of the device are too worn too much and there is a strong shrinkage of springs.
As you can see, the DVS system faults may be more than enough. That is why it is necessary to determine exactly what it is necessary to spend comprehensive diagnosis. Moreover, for some manipulations, special equipment is necessary.
Almost all of the faults described above can be corrected. Full replacement DVS power systems are needed only in extreme cases. Moreover, even simple adjustment can fully restore the performance of the automotive node.
DVS restoration methods working on diesel
To restore the device's performance, you need to clean the blowing windows from the car, if it is present there. Check if the lubricant coupling is enough. If the amount of lubricant is minimal - add it to an acceptable volume
Most often, the engine knocks and smokes in cases where the fuel poured to you has a small cetane number. Fortunately, the recipe for exit from this situation is pretty simple. It is enough to change the fuel fluid to the one in which this indicator will be greater than 40.
Injector Engine
Injector motor power system
Injector power systems have become applied at the beginning of the 80s of the last century. They came to shift designs with carburetors. In a device running with an injector, each cylinder has its own nozzle.
Nozzles are attached to the fuel frame. Inside this design, the fuel fluid is under pressure that provides a pump. The longer period of time the nozzle is open, the more the amount of fuel is injected inside.
The period that nozzles are in the open position controls the electronic controller. This is a kind of control unit with a clearly built control algorithm. He will agree on the opening moment with sensor readings. The work of the electronic filling does not stop for a second. This ensures a stable fuel supply.
Important! A special sensor is responsible for air flow. It is in cycles that the filling of cylinders is calculated.
Load for throttle valve Determines a separate sensor. More precisely, he conducts calculations. After that, sends the data to the controller, where reconciliation is reconcilized and adjustments are carried out if necessary.
If we talk about the injectory system of the power supply system, it is almost fully working due to the indicators of the set of sensors. You can find the most important sensors responsible for such parameters:
- temperature
- position crankshaft,
- oxygen concentration
- monitoring detonation when igniting.
Moreover, it is only the main sensors. In fact, in the nutrition system, you are much more.
Fault
As mentioned above, the DVS power system is almost completely built on the operation of the sensors. The greatest harm can be damaged by the sensor responsible for the crankshaft. If this happens, you will not even come to the garage. It will also happen if the benzonasos fails.
Important! If you are going to a long trip, take a spare gas station with you. This is the second heart of your car.
If we say about the safest power supply system malfunctions, this is definitely a phase sensor breakdown. This defect will cause the least damage to the car. In addition, the repair will take a minimum of time.
Important! The phase sensor malfunction says unstable work Injectors. Usually this is evidenced by a sharp jump of gasoline consumption.
Carburetor engines
Supply system
The first carburetor engine was created in the last century Gotlib Daimler. The carburetor engine power system is not particularly difficult and consists of elements such as:
- fuel tank,
- pump,
- fuel line
- filters
- carburetor.
The capacity of the tank is usually about 40-80 liters in cars with carburetor power systems. This device In most cases, mounted in the back of the machine for greater safety.
From the fuel tank, gasoline enters the carburetor. Connects these two devices fuel line. It takes place under the bottom of the vehicle. In the process of transporting the fuel passes several filters. The pump is responsible for the feed.
Fault
The design is the oldest of all three. Despite this, its simplicity helps to significantly reduce the risk of any breakdown. Unfortunately, no DVS nutrition system, including carburetor, can occur with such defects:
- deletion of the fuel mixture,
- termination fuel supply,
- gasoline leak.
Heights are easily noted by the naked eye. The termination of the supply of fuel fluid will not allow auto to move. If the carburetor sneezes, it means that the fuel mixture is depleted.
RESULTS
During the years of development of the automotive industry, a variety of DVS power systems were created. The first was carburetor. It is the simplest and unpretentious. Its successors are diesel and injector.
Fuel system fuel (SPT) - is designed to supply fuel under high pressure in cylinder combustion chambers at certain points in time (characterized by an angle of fuel transfer) and in a certain amount depending on the engine load.
The diesel engine power system consists of:
Fuel supply systems (Fig. 1);
Air power systems (Fig. 2);
Output systems of exhaust gases (Fig. 3).
Fig. 1. Fuel supply system.
Fig. 2. Food system by air Fig. 3. Output systems of exhaust gases.
Fuel system fuel (SPT) - designed to supply fuel under high pressure in cylinder combustion chambers at certain points in time (characterized by an angle of fuel lead) and in a certain amount depending on the engine load (Fig. 4).
The composition of the SPT: fuel tanks; Fuel pumping pump; low pressure fuel pump; coarse filter (FGO); Filter of fine cleaning (FTO); high pressure fuel pump (TNVD); nozzles; Low pressure pipelines; high pressure pipelines; Drain pipes.
Fig. 4. Composition of the fuel nutrition system.
Circuit system of the system.
Fuel From the tank through a coarse purification filter is suused with a fuel-pumping pump and a low-pressure fuel pipeline filter is supplied to a high-pressure fuel pump, which, according to the order of the engine, distributes fuel to high pressure fuel supply to the injectors. The nozzles spray and injected fuel in the combustion chamber. Excessive fuel, and with it, and air through the airproof high pressure fuel pump valve and the fuel filter valve and the drainage fuel lines are discharged into the fuel tank. The fuel surrounded through the gap between the housing of the sprayer and the needle is merged into the tank through drain fuel pipelines.
High Pressure Fuel Pump Designed to feed into the engine cylinders at certain points in time, strictly dosed portions of fuel under high pressure.
Eight sections are installed in the housing, each consists of a housing, a plunger sleeve, a plunger, a swivel sleeve, a discharge valve, pressed through the sealing gasket to the plunger sleeve fitting. The plunger makes a reciprocating movement under the action of the cam and springs cam. The pusher from turning in the housing is fixed with a sukhar. The cam tree rotates in the bearings installed in the lids and attached to the pump housing. The axial clearance of the cam shaft is regulated by gaskets. The magnitude of the gap should be no more than 0.1 mm.
To increase the fuel supply, the plunger rotate the sleeve connected through the axis of the leash with the rack of the pump. Rake moves to guide bushings. The protruding end is closed by a plug. From the opposite side of the pump there is a bolt regulating the supply of fuel by all sections of the pump. This bolt is closed by a plug and polished.
The fuel to the pump is supplied through a special fitting, to which a low pressure tube is attached to the bolt. Next, through the channels in the case, it enters the inlet holes of the plunger sleeves.
At the front end of the housing, at the outlet of the fuel from the pump, the bypass valve is installed, the opening of which occurs at a pressure of 0.6-0.8 kgf / cm2. The opening pressure of the valve is regulated by the selection of adjusting washers inside the valve tube.
Pump lubrication circulating, pulsating, under pressure from common system Engine lubricants.
Fuel tanks (Fig. 5). Each tank consists of a housing, a fuel neck and a retractable pipe with a mesh filter. The bay neck is closed with a hermetic lid 6 with a gasket. In order to increase the rigidity of the tank, as well as reducing the shabby of fuel and the formation of foam in the tank there are partitions.
Fig. 5. Fuel tank:
I-i-iii - the position of the crane, respectively, when the tanks turned on, turned on by the right tank, turned on by the left tank; 1 - fuel plum tube into the tank; 2 - fuel distribution valve on the plum line; 3 - fuel distribution valve on the fuel supply line; 4 - flange; 5 - Fuel Tube with a mesh filter; 6 - lid; 7 - the bay neck; 8 - body; 9 - partition; 10 - bottom; 11 - plug crane
At the bottom of the tank there is a plug crane for draining sludge. In the upper part of the left tank, a fuel distribution crane is installed, designed to turn on the fuel supply from the right tank or left, as well as to disconnect the tanks, and the fuel valve valve on the drain line, providing fuel plums or into the right or left tank. Fuel distribution cranes have three positions. To activate the fuel supply from the right tank, it is necessary to set the cranes to position II, from the left tank - to position III, to turn off the tanks of the fuel valve on the fuel line, set to I.
Manual pumping pump - To pre-fill the supply system with fuel and remove air from it.
Filter coarse fuel Fuel KAMAZ-740 - Sustainer Pre-cleansing fuel entering the low-pressure fuel pumping pump. It is installed on the left side of the car on the frame (Fig. 6).
Fig. 6. Filter of rough filter of fuel Diesel KAMAZ-740
The coarse fuel filter of the YMZ-238 diesel fuel (Fig. 7) consists of a cover, housing and a filter element. The housing and cover are connected by four bolts. The seal between them is provided with a rubber gasket. There is a traffic jam on the case drain hole With gasket. The filter consists of a metal frame with holes to which pushed cotton cord.
Fig. 7. Filter of coarse cleaning of fuel Diesel YMZ-238
To center the filter element, there is a socket welded to the housing, and the protrusion on the lid. The filter element is tightly clamped along the ends between the lid and the bottom of the case. The hole in the lid, closed by a plug with a gasket, serves to fill the filter with fuel.
Filter of fine fuel purification (Fig. 8, 9) finally cleans the fuel before entering the high pressure fuel pump, installed in the highest point of the power supply system to collect and remove into the power supply in the air supply system along with a part of the fuel via the fuel valve.
To improve the quality of fuel purification, the fine cleaning filter is equipped with two parallel replaceable filtering elements made of special paper and installed in one dual housing.
The fuel filter of the YMZ-238 diesel fuel purification consists of a housing with a rod, covers and a filtering element. A replaceable filter element consists of a perforated metal frame, on which the filter mass is mounted.
Fig. 8. Filter of fine cleaning fuel diesel engine KAMAZ-740
1 - body; 2 - bolt; 3 - Sealing washer; 4 - traffic jam; 5 and 6 - gaskets; 7 - filter element; 8 - Cap; 9 - spring filter element; 10 - plug plug; 11 - Rod.
Fig. 9. Filter of fine cleaning fuel diesel engine YMZ-238
1 - plug plug; 2 - gasket; 3 - spring; 4 - washer; 5 - gasket; 6 - filter element; 7 - case; 8 - rod; 9 - Gasket: 10 - Cover: 11 - conical plug; 12 - Gasket: 13 - bike; 14 - bolt; 15 - gasket; 16 - Gasket
Fuel pumping pump. The design pump is the same for the diesel engine KAMAZ-740.11 and for the YAMZ-238, it is designed to supply fuel from the fuel tank to a high pressure pump. Fuel pumping pump piston type It is activated from the eccentric cam shaft of high pressure pump. The pump is installed on the pump of the TNVD.
Fig. 10. Schemes of fuel-pumping and fuel ripping pumps: (Slide number 11)
A - the bustling of the fuel pumping pump; B - the cavity of the absorption of the fuel pumping pump; In - to the fuel purification filter; G - cavity suction of the fuel rolling pump; D - from the filter of coarse fuel purification; 1 - piston; 2 - inlet valve; 3, 7 - valve springs; 4 - Piston Spring; 5 - fuel pumping pump; 6 - discharge valve; 8 - spring pusher; 9 - eccentric; 10 - pusher; 11 - discharge valve; 12 - inlet valve; 13 - Spring; 14 - fuel rolling pump; 15 - Piston
The fuel-pumping manual pump serves to fill the supply system with fuel and remove air from it. Piston type pump, fixed on a low-pressure fuel pump flange with a sealing copper washer or flexible fuel filter. The pump consists of a housing, piston, cylinder, handles assembly with a rod, support plate and sealing.
When the piston movement 15 down the intake valve 12 closes and discharge valve 11, the fuel under pressure enters the injection line, ensuring the removal of air from the fuel system of the engine through the valve 2 of the fuel purification filter and the high pressure fuel pump valve.
After pumping the system, it is necessary to lower the piston15 and fix it with turning clockwise. At the same time, the piston is pressed against the cylinder end through the rubber gasket, complicating the absorption cavity of the fuel pumping pump.
After pumping, the handle must be screwed into the upper threaded cylinder shank. In this case, the piston is squealing to rubber strip, compacting the suction cavity of low pressure fuel pump. Many modifications of the KAMAZ family modifications have been installed the second single-type pump for manual fuel swap. It allows you to drive up the fuel without tipping the cab, since it is fixed through the bracket on the crankcase
The supply systems of gasoline and diesel engines are significantly different, so we consider them separately. So, what is a car power system?
Power supply system of gasoline engine
Power supply systems of gasoline engines are two types - carburetor and injection (injection). Since on modern cars The carburetor system is no longer applied below. Consider only the basic principles of its work. If necessary, you can easily find additional information on it in numerous special editions.
Power supply system of gasoline engine, regardless of the type of engine internal combustion, designed to store fuel reserves, cleaning fuel and air from extraneous impurities, as well as air and fuel supply to the engine cylinders.
To store the stock of fuel on the car serves the fuel tank. On modern cars, metal or plastic fuel tanks are used, which in most cases are located under the bottom of the body in the rear.
The power supply system of the gasoline engine can be divided into two subsystems - air supply and fuel supply. Whatever happens, in any situation, our experts on visiting those relief on the roads of Moscow will come and provide the necessary assistance.
Carburator type gasoline engine power system
In the carburetor engine, the fuel supply system works as follows.
The fuel pump (fuel pump) supplies fuel from the tank to the float chamber of the carburetor. The fuel pump, usually membrane, is located directly on the engine. The drive of the pump is carried out with the pusher rod by an eccentric on the camshaft.
Cleaning fuel from pollution is performed in several stages. The coarsest cleaning occurs with a meshe on the fence in the fuel tank. Then the fuel is filtered by the grid at the entrance to the fuel pump. Also, the mesh filter sump is installed on the inlet nozzle of the carburetor.
In the carburetor, the purified air from the air filter and gasoline from the tank is mixed and fed into the intake pipeline of the engine.
The carburetor is arranged in such a way as to ensure the optimal ratio of air and gasoline in the mixture. This ratio (by weight) is approximately 15 to 1. The fuel-air mixture with such an air ratio to gasoline is normal.
The normal mixture is necessary for the engine operation in the steady mode. In other modes, the engine may require fuel-air mixtures with a different ratio of components.
The depleted mixture (15-16.5 parts of the air to one part of the gasoline) has a smaller combustion rate compared to enriched, but the fuel combustion is completely combustion. The depleted mixture is used at medium loads and provides high efficiency, as well as the minimum emission of harmful substances.
The poor mixture (more than 16.5 parts of the air to one part of the gasoline) is very slow. On the poor mixture there may be interruptions in the engine operation.
The enriched mixture (13-15 parts of the air to one part of the gasoline) has the highest combustion rate and is used with a sharp increase in load.
A rich mixture (less than 13 parts of air to one part of gasoline) is slow. A rich mixture is needed when starting a cold engine and subsequent work at idle.
To create a mixture other than normal, the carburetor is equipped with special devices - an economizer, an accelerating pump (enriched mixture), an air damper (rich mixture).
In the carburetors of different systems, these devices are implemented in different ways, so here we will not consider them in more detail. The essence is just that carburator type gasoline engine power system Contains such structural elements.
To change the amount of fuel and air mixture and, therefore, the rotational speed of the crankshaft is the throttle valve. It is the driver who manages the driver, pressing or the release of the gas pedal.
Injector gasoline engine power system
By car with fuel injection system, the driver also controls the engine through throttle, but at this analogy with carburetor gasoline engine power system ends.
The fuel pump is located directly in the tank and has an electric drive.
The electrical displacement is usually combined with the fuel level sensor and the mesh filter to the node called the fuel module.
On most injection vehicles fuel from the fuel tank under pressure enters a replaceable fuel filter.
The fuel filter can be installed under the bottom of the body or in the engine compartment.
Fuel pipelines are connected to the filter with threaded or quick-consuming connections. The compounds are sealed with ribbed rubber rings or metal washers.
Recently, many automakers began to abandon the use of similar filters. Fuel purification is made only by the filter installed in the fuel module.
Replacing such a filter is not regulated by the maintenance plan.
Fuel injection systems There are two main types - the central fuel injection (monovosprysk) and distributed injection, or, as they are also called, multipoint.
The central injection became for automakers in the transition stage from the carburetor to the distributed injection and on modern applications does not find. This is due to the fact that the central fuel injection system does not allow the requirements of modern environmental standards.
The central injection unit is similar to the carburetor, only instead of a mixing chamber and jets inside the electromagnetic nozzle is installed, which opens by the command electronic block Engine control. Fuel injection occurs on the inlet of the inlet pipeline.
In the distributed injection system, the number of nozzles is equal to the number of cylinders.
Nozzles are installed between the inlet pipeline and the fuel ramp. A constant pressure is maintained in the fuel ramp, which is usually about three bar (1 bar is approximately 1 atm). To limit the pressure in the fuel rail, the regulator is served, which blends the excess fuel back to the tank.
Previously, the pressure regulator was installed directly on the fuel ramp, and to connect the regulator with fuel tank A reverse fuel line was used. IN modern systems The supply of gasoline engine The regulator is placed in the fuel module and the need for the return highway disappeared.
Fuel nozzles are opened by the commands of the electronic control unit, and the fuel injection from the ramp in the intake pipeline, where the fuel is mixed with air and comes in the form of a mixture into the cylinder.
The commands for opening the nozzles are calculated on the basis of signals coming from sensors. electronic system Engine control. This ensures synchronization of the operation of the fuel supply system and the ignition system.
Injector gasoline engine power system Provides greater performance and the ability to match higher environmental standards than carburetor.
