General device automotive motor power system. Internal combustion engine power system. Power supply systems and exhaust gases of the car engine

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 to 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 power supply system diesel engine, you need to know what is diesel fuel 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 general System food 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 this 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:

1. 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.
2. 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.
3. 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.
4. 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.
5. Non-cotton. The reason for such a malfunction in the power system of the engine lifting in the air seats.
6. 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.

The load for the 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, these are 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 is 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. She passes under the bottom 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, then 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.

Purpose, device and operation of the supply system fuel

The fuel engine power system is designed to place the fuel reserve by car, cleaning, spraying the fuel and the uniform distribution of it by cylinders in accordance with the order of the engine.

The KAMAZ-740 engine uses a separation type fuel system (i.e., high-pressure fuel pump functions and nozzles are separated). It includes (Fig. 37) Fuel tanks, fuel filter coarse cleaning fuel filter thin cleaning, Fuel pumping pump * Low pressure, Hand pump pumping pump, high pressure fuel pump (TNVD) with a milk regulator and an automatic fuel injection lifting coupling, nozzles, high and low pressure fueling and measuring instruments.

Fuel from the fuel tank under the action of the vacuum generated by the fuel-pumping pump, through the filters of coarse and thin purification by low-pressure fueling powdles is supplied to the high pressure fuel pump. In accordance with the order of the engine (1-5-4-2-6-3-7-8-8), the TNVD supplies fuel under high pressure and certain portions through the nozzles in the combustion chamber of the engine cylinders. Injectors fuel sprayed. Excess the fuel, and with them and the air in the system through the ottld valve and the valve-fat valve of the fine cleaning filter are discharged into the fuel tank. Fuel surceded through the gap

Fig. 37. Fuel engine power system:
1 - fuel tank; 2 - fuel line to coarse filter; 3 - tee; 4 - Filter of coarse fuel purification; 5 - drain drainage fuel line injectors of the left row; 6 - nozzle; 7 - Sliding fuel line to low pressure pump; 8 - high pressure fuel pipe; 9 - manual fuel pumping pump; 10 is a top-level low pressure pump; 11 - fuel line to fine filter; 12 - high pressure fuel pump; 13 - fuel line to the electromagnetic valve; fourteen - solenoid valve; / 5-drain drainage fuel line injectors of the right row; 16 - flare candle; P - drainage fuel pipeline of high pressure pump; 18 - Filter of fine fuel purification; 19 - Supporting fuel line to high pressure pump; 20 - drainage fuel filter fuel pipeline; 21 - drain fuel line; 22 - distribution crane

Fig. 38. Fuel tank:
1 - bottom; 2 - partition; 3 - body; 4 - plug crane; 5 - bulk tube; 6 - plug of bulk pipe; 7-second tape; 8 - Bracket Bracket Bracket

Fuel tanks (Fig. 38) are intended for accommodation and storage by car defined. Fuel supply. The KAMAZ-4310 car has two tanks with a capacity of 125 liters each. They are located on both sides of the car on the spars of the frame. The tank consists of two halves, stepped out of sheet steel and connected by welding; For corrosion protection, it is overwritten from the inside.

Inside the tank there are two partitions that serve to mitigate hydraulic fuels of fuel on the wall when the car is moving. The tank is equipped with a filling neck with a pull-out pipe, a filter grid and a hermetic lid. At the top of the tank, the fuel indicator sensor of the fuel level of the fuel is installed, a tube performing the role of an air valve. At the bottom of the tank, the intake tube and a fitting with a crane for draining sludge. At the end of the intake tube there is a strainer.

Filter of coarse fuel purification (Fig. 39) is intended for pre-purification of the fuel entering the fuel supply pumping pump. Mounted on the left side on the car frame. It consists of a housing, a reflector with a filter grid, a distributor, a sedator, a glass of filter, applying and discharge fittings with gaskets. A glass with a lid is connected by four bolts through a rubber sealing "JU gasket. A drain plug screws into the lower part of the glass.

The fuel coming through the tubing tank fitting is supplied to the distributor. Large extraneous particles and water are collected at the bottom of the glass. From the upper part of the fuel through the mesh filter, it is supplied to the discharge piece, and from it to the fuel supply pumping pump.

Filter of fine fuel purification (Fig. 40) is designed for final fuel purification before entering it into a high-pressure fuel pump. The filter is installed in the rear of the engine at the highest point of the power system. Such an installation provides air collection that has fallen into the system, and its removal in the fuel tank through the magnifier valve. The filter consists of a housing,

two filtering elements, two caps with welded rods, valve-gibera, supplying and discharge fittings with sealing gaskets, seal elements. The housing is cast from aluminum alloy. It contains channels for supplying and removing fuel, cavity to install valve-gibber and ring poles for installing the caps.

Replaceable cardboard filter elements are made of highly porous Cardboard type ETFS. The end seal of the elements is carried out by the upper and lower seals. The dense fit of the elements to the filter housing is provided by springs installed on the rods of the caps.

The magnifier valve is designed to remove air in the system. It is installed in the filter housing and consists of a cap, the springs of the valve, cork, adjusting washer, sealing washer. The fat valve opens when the pressure in the cavity in front of the valve is equal to 0.025 ... 0.045 MPa (0.25 ... 0.45 kgf / cm2), and at a pressure of 0.22 ± 0.02 MPa (2.2 ± 0.2 kgf / cm2) Begins torture fuel.

The fuel under pressure from the fuel-pumping pump fills the inner cavity of the cap and is pushed through the filter element, mechanical impurities remain on the surface. Purified fuel from the inner cavity of the filter element is supplied to the intake cavity of the pump.

Fig. 39. Filter of coarse fuel purification:
1 - drain plug; 2 - a glass; 3 - sedative; 4 - Mesh filtering; 5 - reflector; 6 - distributor; 7 - bolt; 8- flange; 9-ring sealing; 10 - housing

The low-pressure fuel pumping pump is designed to supply fuel through coarse and thin cleaning filters to the intake cavity of the TNVD. Pump piston type driven from the eccentric cam shaft TNVD. Pressure supply 0.05 ... 0.1 MPa (0.5 ... 1 kgf / cm2). The pump is installed on the back cover of the TNVD. The fuel pumping pump (Fig. 41, 42) consists of a housing, piston, piston springs, piston pusher, pusher rod, pusher springs, rod sleeve guide, inlet valve, injection valve.

Pig-iron pump housing. It contains channels and cavities for piston and valves. The cavities under the piston and above the piston are connected by the channel through the injection valve.

The pusher is designed to transmit effort from the eccentric cam shaft piston. Roller-type pusher.

The eccentric cam shaft of the pump through the pusher and the rod informs the piston of the pump (see Fig. 41) a reciprocating movement.

Fig. 40. Filter of fine fuel purification:
1 - body; 2 - bolt; 3 - sealing washer; 4 - traffic jam; 5, 6 - gaskets; 7 - element filtering; 8 - Cap; 9 - spring filter element; 10 - drain plug; 11 - Rod.

When lowering the pusher, the piston under the action of the spring moves down. In the suction cavity, it creates a vacuum, the inlet valve opens and passes the fuel into the above-piston cavity. At the same time, fuel from the pouring cavity through a fine cleaning filter enters the intake Channels of the TNVD. When the piston moves up the ink valve closes and fuel from the pickup cavity through the injection valve enters the cavity under the piston. When the pressure in the injection line B rises, the piston stops after the pusher move down, but remains in a position that is determined by the equilibrium of the forces from the fuel pressure on one side and the spring force on the other. Thus, the piston makes no complete move, but a partial one. Thus, the performance of the pump will be determined by fuel consumption.

Manual fuel pumping pump (see Fig. 42) Designed to fill the fuel system and remove air from it. The piston type pump is attached on the housing of the brawl pump through the sealing copper puck.

The pump consists of a housing, piston, cylinder, piston rod and handle, support plate, inlet valve (total with a fuel pumping pump).

Filling and pumping the system is carried out by the movement of the handle with the rod up-down. When the handle is moving up in the rowing space, a vacuum is created. The intake valve opens and fuel enters the cavity above the piston of the fuel pumping pump. When the handle moves down, the fuel-pumping pump discharge valve opens and fuel under pressure enters the injection line. Next, the process is repeated.

After pumping, the handle must be tightly screwed onto the top threaded cylinder shank. In this case, the piston is tormented to rubber strip, sealing inlet of the fuel pumping pump.

Fig. 41. Scheme of the fuel-pumping pump of low pressure and manual fuel pumping pump:
1 - Eccentric Drive Drive; 2 - pusher; 3 - piston; l - intake valve; 5 - manual pump; 6 - Purpose 4 Valve

The high pressure fuel pump (TNVD) is designed to supply dosage portions of fuel under high pressure into the engine cylinders in accordance with the order of their operation.

Fig. 42. Fuel pumping pump:
1 - Eccentric Drive Drive; 2 - roller pusher; 3 - case (cylinder) pump; 4 - spring pusher; 5 - rod of the pusher; 6 - Stem sleeve; 7 - piston; 8 - Piston Spring; 9 - High Pressure Pump Corps; 10 - inlet valve seat; 11- Housing of low pressure fuel pumping pump; 12 - inlet valve; 13 - Valve Spring; / 4 - manual pumping pump; 15 - washer; 16 - the plug of the discharge valve; 17 - the spring of the discharge valve; 18 - low pressure fuel pump discharge valve

Fig. 43. High pressure fuel pump: 1 - rear regulator cover; 2, 3 - the leading and intermediate gear of the regulator of the frequency of rotation; 4- driven gear of the regulator with cargo holder; 5 - cargo axis; 6 - cargo; 7-coupling of goods; 8 - Finger lever; 9 - corrector; 10 - lever of the springs of the regulator; 11 - Rake; 12 - rail sleeve; 13 - reduction valve; 14 - Reiki traffic jam; 15 - YUFTA fuel injection; 16 - cam shaft; 17, - pump housing; 18 - Pump section

The pump is installed in the collapse of the cylinder block and drives from the gear distribution Vala. Through the pump drive gear. The direction of rotation of the cam shaft from the drive side is right.

The pump consists of a housing, a cam shaft (see Fig. 43), eight pumping sections, an all-mode regulator of the rotational frequency, fuel injection and fuel pump drive coupling.

The TNLD housing is designed to place pump sections, cam shaft and rotational speed control. Molding from aluminum alloy, it contains inlet and cut-off channels and cavities for installation and fastening of pumping sections, cam shaft with bearings, gear of the controller drive, supplying and reducing fuel fittings. In the rear end of the pump housing, the lid of the regulator is attached, in which the low-pressure fuel pumping pump is located with the pumping pump of the fuel. On top of the lid, the fitting with the oil oil tube for lubricating the parts of the pump under pressure is screwed. The oil from the pump merges along the tube connecting the lower hole of the regulator cover with the hole in the block collapse. The upper cavity of the TNVD housing is closed with a lid (see Fig. 44), on which the control knob control levers and two protective casing of the pump fuel sections are located. The cover is installed on two pins and is fastened with bolts, and protective covers - with two screws. At the front end of the pump housing at the outlet from the shut-off channel, a fitting was screwed with a ball-type bypass valve supporting the excess fuel pressure in the pump 0.06 ... 0.08 MPa (0.6 ... 0.8 kgf / cm2). At the bottom of the pump housing, a cavity is made to install a cam shaft.

The cam tree is designed for the movement of pumping sections in plungers and ensuring a timely fuel supply to the engine cylinders. The cam shaft is made of steel. The working surfaces of the cams and the supporting necks are cemented to a depth of 0.7 ... 1.2 mm. Due to the co-circular design of the pump, the cam shaft has a smaller length and, therefore, has a higher rigidity. The shaft rotates in two tapered bearings, the internal roles of which are pressed on the shaft neck. The axial clearance of the cam shaft 0.1 mm is regulated by gaskets installed under the bearing cover. For sealing cam shaft in the lid there is a rubber cuff. At the front cone end of the cam shaft on the segment key, an automatic coupling of the fuel injection angle is installed. At the rear end of the cam shaft, a stubborn sleeve is mounted, the leading gear of the regulator assembly, and on the prismatic key - the flange of the leading gear of the regulator. The flange is made together with the eccentric of the fuel-powder pumping pump. The torque from the cam shaft on the leading gear of the regulator is transmitted through the flange through rubber crackers. When the cam shaft rotates, the force is transmitted to roller pushers and through the pushers' stains to plungers of pumping sections. Each pusher from rotation is fixed with a sukhara, the protrusion of which is included in the pump sliding groove. Due to changes in thickness, the fifth is regulated by the start of fuel supply. When installing the fifth of greater thickness, the fuel starts to be supplied earlier.

Fig. 44. Controller cover:
1 - Bolt of adjustment of the launcher; 2 - stop lever; 3 - Bol * regulation of the stop lever; 4 - bolt restrictions of the maximum rotational speed; 5 - control lever regulator (fuel pump rail); 6 - bolt restrictions of the minimum rotation frequency; I - work; IT - off

Pump section (Fig. 45, a) is a part of the high-pressure fuel pump, which is dosing and feeding the fuel to the nozzle. Each pump section consists of a corpurz, plunger pair, swivel sleeve, springs plunger, discharge valve, pusher.

The enclosure of the section has a flange, with which the section is attached on the heels, screwed into the pump housing. Holes in the flange under the studs have an oval shape. This allows you to rotate the pumping section to regulate the uniformity of the fuel supply by individual sections. When you turn the section counterclockwise, the cycle feed increases, clockwise decreases. In the section of the section, two holes are made for the passage of fuel from the channels in the pump to the holes in the plunger sleeve (A, B), the hole for installing the pin fixing the position of the sleeve and the plunger relative to the section of the section, and the slot for placing a swivel sleeve.

Plunger pair (Fig. 45, b) is the node of the pump section, directly intended for dosing and fuel supply. Plunger pair includes a plunger and plunger bushing. They represent a precision pair. Made from chromolibdden steel, are undergoed by quenching, followed by a deep cold processing to stabilize the properties of the material. Work surfaces of the bushings and plunger nitrate.

Fig. 45. Section of the high pressure fuel pump:
a - design; B - the upper part of the plunger pair; A - cavity of the fuel pump injection; B - cutoff cavity; 1 - pump housing; 2- pusher section; 3 - heel pusher; 4 - Spring: 5, 14-Plunger Section; 6, 13 - Plunger's sleeve; 7 - discharge valve; 8 - fitting; 9 - section of the section; 10 - shut-off edge of the screw groove of the plunger; 11 - Rake; 12 - Plunger Rotary Bushing

The plunger is a movable piece of plunger pair and performs the role of piston. The plunger in the upper part has axial drilling, two spiral grooves made from two sides of the plunger, and a radial drilling connecting the axial drilling and grooves. The spiral groove is designed to change the cycle supply of fuel due to the rotation of the plunger, and consequently, the grooves relative to the cut-off plunger sleeve. The rotation of the plunger relative to the sleeve is carried out by the fuel pump rail through the spikes of the plunger. There is a label on the outer surface of one spike. When assembling the section, the tag on the plunger spike and the slot in the case of the section to install the leash of the swivel sleeve must be on the one hand. The presence of the second groove provides the hydraulic unloading of the plunger from the side effort. Due to this, the reliability of the pump section is increasing.

The seal between the sleeve and the section of the section is provided by a ring of oil-resistant rubber installed in the annular groove of the sleeve.

The discharge valve and its saddle are made of steel, hardened and treated with deep cold. The valve and saddle are a precision pair, in which the replacement of one part on the same name from another set is not allowed.

The discharge valve is located at the upper end of the sleeve and pressed to the saddle of the spring. The saddle of the discharge valve is pressed to the sleeve of the plunger of the end surface of the fitting through the sealing textolite gasket.

Purchase valve of fungal type with cylindrical guide part. The radial opening with a diameter of 0.3 mm is used to adjust the cycle feed at the rotation frequency of the cam shaft 600 ... 1000 min-1. The adjustment is carried out by increasing the throttle action of the valve during the cut-off of the supply, as a result of which the amount of fuel flowing from the high pressure fuel line into the admisted space is reduced. High-pressure fuel supply unloading is carried out by moving when boarding the valve guide in the saddle channel. The upper part of the guide serves as a piston, sucking fuel from the fuel line.

Protective speed regulator. Engines internal combustion Must work on a given steady (equilibrium) mode, characterized by the constancy of the rotation of the crankshaft, the temperature of the coolant and other parameters. Such a mode of operation can only be supported by equality of the engine torque of the engine torque resistance. However, during operation, this equality is often disturbed due to a change in the load or the specified mode, so the parameter value (rotational speed, etc.) is deviated from the specified. Regulation is applied to restore the impaired engine operation mode. Adjustment can be done manually by impact on the control body (fuel pump rail) or using a special device called automatic rotational speed regulator. Thus, the rotational speed controller is designed to maintain the crankshaft rotational speed driver by automatically changing the fuel cycle, depending on the load.

On the KAMAZ engine there is a seven-minded centrifugal regulator of the rotational speed of direct action. It is placed in the collapse of the TNVD case, and the control is displayed on the pump cover.

The regulator has the following elements (Fig. 46):
- specifying device;
- sensitive element;
- comparing;
- actuating mechanism;
- Controller drive.

The control device includes the control lever, the springs lever, the regulator spring, the knob of the regulator, the lever with the proofreader, the adjusting bolts of the speed of rotation frequency.

The sensitive element includes a regulator shaft with a cargo holding, loads with rollers, thrust bearing, the clutch of the regulator with fifth.

The comparing device includes the cargo couplings lever, with which the movement of the regulator coupling is transmitted. executive mechanism (Rakes).

The actuator includes the fuel pump rails, the rail lever (differential lever).

The drive of the regulator includes a leading gear of the regulator, the intermediate gear 6, the gear of the regulator, made in one integer with the shaft of the all-mode regulator.

To stop the engine there is a device in which the stop lever includes the break lever spring, the starting spring, the restriction bolt of the stop lever, the starting feed bolt.

Fuel management is controlled by foot and manual drives.

The rotation of the leading gear of the regulator is transmitted through rubber crowns. Sugari, being elastic elements, quenching oscillations associated with the uneven rotation of the shaft. The decrease in high-frequency oscillations leads to a decrease in the wear of the joints of the main parts of the regulator. From the leading gear, rotation to the slave gear is transmitted through an intermediate gear.

The driven gear is done at the same time with the cargo of cargo rotating on two ball bearings. When the maintenance of the cargo is rotated under the action of centrifugal forces, it is diverged and through the thrust bearing move the clutch, the coupling, resting in the finger, in turn, moves the cargo coupling lever.

The cargo coupling lever is mounted in one end on the axis of the regulator levers, another through the pin is connected to the fuel pump rail. The axis also attaches the lever of the regulator, the other end of which moves to the stop in the adjusting bolt of fuel supply. The cargo coupling lever affects the knob of the regulator through the corrector. The control lever regulator is rigidly connected to the lever of the springs of the regulator.

Fig. 46. \u200b\u200bRotation frequency regulator:
1 - rear cap; 2 - nut; 3 - washer; 4 - Bearing; 5 - adjusting gasket; 6 - gear intermediate; 7 - Laying the back cover of the regulator; 8 - Ring lock; 9- cargo holder; 10 - cargo axis; 11 - the bearing is stubborn; 12 - coupling; 13 - cargo; 14 - finger; 15 - corrector; 16 - Returning Spring Stay Lever; 17 - bolt; 18 - sleeve; 19 - Ring; 20 - springs lever regulator; 21 - Master's gear: 22 - Truck leading gear; 23 - Flange of the leading gear; 24 - Adjusting fuel supply bolt; 25 - Starting lever

The starting spring is attached to the starting spring lever and the rail lever. Reiki, in turn, are associated with swivel sleeves of pumping sections. Reducing the degree of non-uniformity of the regulator at the small frequencies of rotation of the crankshaft is achieved due to the change of the shoulder of the application of the supplement springs of the regulator to the lever of the regulator.

The increase in the sensitivity of the regulator is ensured by the quality processing of the driving surfaces of the movable parts of the regulator and the pump, reliable lubrication and the increase in the angular velocity of rotation of the cargo coupling by two times the path of the pump shaft due to the gear ratio of the drive gear of the regulator.

On the engine installed a rotational speed regulator with a smoke traffic, which is built into the cargo coupling lever. The corrector, reducing the fuel supply, reduces the engine smoke at the low speed of the crankshaft (1000 ... 1400 min).

Specified speed mode The engine operation is set by the control lever, which turns and through the springs lever increases its tension. Under the influence of this spring, the lever through the corrector affects the coupling lever, which moves the rails associated with the rotary sleeves of the plungers, up to increase the fuel supply. The crankshaft rotation frequency increases.

The centrifugal force of rotating goods through the stubborn bearing, the coupling and arm of the cargo couplings is transmitted to the fuel pump rail, which is connected to another rail through the differential lever. Moving the records of centrifugal power of goods causes a decrease in fuel supply.

Adjustable high-speed mode depends on the ratio of the power of the regulator's spring and centrifugal force of goods at the set rotation frequency of the crankshaft. The larger the springs of the regulator stretch, with higher high-speed mode, its loads can change the position of the regulator lever towards limiting the fuel supply to the engine cylinders. Sustained engine operation will be in the event that the centrifugal power of goods will be equal to the power of the springs of the regulator. Each position of the control lever of the regulator corresponds to a certain rotation frequency of the crankshaft.

At a given position of the control lever, in case of a reduction in the load on the engine (movement to the descent), the rotational speed of the crankshaft, and consequently, the drive shaft of the regulator rises. In this case, the centrifugal power of cargo increases and they disagree.

Loads affect the stubborn bearing and, overcoming the spring force specified by the driver, rotate the regulator lever and move the rails towards the reduction of the supply since the fuel supply is not established, which corresponds to the conditions of movement. The specified speed engine mode will be restored.

With an increase in the load (movement on the rise), the speed of rotation, and therefore, the centrifugal forces of goods decrease. The force of spring through the levers 31, 32, acting on the coupling, moves it and brings closer. In this case, the rails are moved towards an increase in fuel supply until the rotational speed of the crankshaft reaches the value specified by the conditions of movement.

Thus, the all-life regulator supports any driver mode set by the driver.

When the engine is operating at the nominal frequency of rotation and complete fuel supply, the M-shaped lever 31 rests on the adjusting bolt 24. In the event of an increase in the load, the speed of rotation of the crankshaft and the regulator shaft begins to decline. At the same time, the equilibrium between the power of the regulator spring and the centrifugal force of its cargo shown in the axis of the regulator lever is disturbed. And due to the excessive force of the springs of the corrector, the corrector plunger moves the coupling lever towards increasing the fuel supply.

Thus, the rotational speed controller not only supports the operation of the engine at a given mode, but also provides an additional fuel portion to the cylinders when working with overload.

Turning off the fuel (stop of the engine) is carried out by turning the stop lever until it stops in the stop lever adjustment bolt. The lever, overcoming the spring force (installed on the lever), will turn over the finger of the regulator lever. Rakes move until the fuel supply is completely shutdown. The engine stops. After stopping the stop lever under the action of the return spring returns to the position of work, and the starting spring through the rope lever will return the rails of the fuel pump in the direction of the fuel supply (195 ... 210 mm3 / cycle).

Automatic fuel injection advance coupling. In diesels, fuel is injected into the air charge. The fuel cannot instantly ignite, but should pass the preparatory phase, during which the fuel mixing with air and its evaporation is carried out. When the temperature of self-ignition reaches the mixture, the mixture flashes and quickly begins to burn. This period is accompanied by a sharp increase in pressure and increasing temperature. In order to get the highest power, it is necessary that the combustion of the fuel occurred in the minimum volume, i.e. when the piston is in the VMT. To this end, the fuel is always injected before the arrival of the piston in the NWT.

The angle determining the position of the crankshaft is relative to the NMT at the time of the start of the fuel injection, is called the fuel injection advance angle. The design of the fuel pump of the diesel engine KAMAZ provides the fuel injection 18 ° to the arrival of the piston in the NTT with compression tact.

With an increase in the rotation frequency of the crankshaft of the engine, the time for the preparatory process is reduced and the ignition can begin after the NTC, which will reduce useful work. In order to get the greatest work with an increase in the rotational speed of the crankshaft, the fuel must be injected before, i.e. increase the fuel injection advance. This can be done due to the rotation of the cam shaft in the direction of its rotation relative to the drive. For this purpose, a fuel injection coupling is installed between the fist of the pump and its drive. The use of the coupling significantly improves the launchers of the diesel engine and its economy at various speed modes.

Thus, the fuel injection advance guard coupling is intended to change the moment of fuel supply, depending on the rotational speed of the crankshaft of the engine.

The KAMAZ-740 applied an automatic centrifugal type of direct action. The adjustment range of the fuel injection ahead is 18 ... 28 °.

The coupling is installed at the conic end of the cam tree of the TNVD on the segment key and is fastened with a ring nut with a spring washer. It changes the fuel injection moment due to the additional rotation of the pump shaft during the engine operation relative to the high-pressure pump drive shaft (Fig. 47).

Automatic coupling (Fig. 47, a) consists of a housing, a leading coupling with fingers, a slave half-carmuft with the axles of cargo, cargo, springs, springs, springs, springs, adjusting gaskets and stubborn washers.

Cast iron coupling housing. In the front end, two threaded holes are made to fill the clutch with engine oil. The housing turns on the slave gunum and stops. The seal between the housing and the leading coupling and the hub, the slave, the semi-carrying is carried out by two rubber cuffs, and between the case and the slave-resistant-resistant rubber rings.

The host of the half-moupel is installed on the hub slave and can be rotated relative to it. The coupling drive is carried out from the drive shaft of the pump (Fig. 47, b). Two fingers are made in the leading half-finger on which spacers are installed. The spacer rests on one end into the finger of the cargo, and the other slides according to the profile of cargo.

The slave of the half-moupel is installed on the conical part of the fist of the TNVD. Two axes of cargo are pressed in the coupling and a label is applied to set the fuel injection ahead. Loads are swinging on the axes in the plane perpendicular to the axis of rotation of the coupling. In cargoes there are profile protrusions and fingers. On cargoes there are efforts of springs.

Fig. 47. Automatic fuel injection lifting coupling:
A - Automatic coupling: 1 - leading of the half; 2, 4 - cuffs; 3 - the bushing of the leading coupling; 5 - case; 6 - adjusting gasket; 7 - a glass of springs; 8 - spring; 9, 15 - washers; 10 - Ring; 11 - cargo with a finger; 12 - Betting with axis; 13 - slave of the half; 14 - sealing ring; 16 - cargo axis
b - automatic clutch drive and installing it by tags; 1 - label nya rear flange demummifs; II - label on the injection advance coupling; III - label on the fuel pump housing; 1 - automatic injection advance coupling; 2 - driven by the drive halfway; 3 - bolt; 4 - Flange Helmwood Drive

With a minimum rotation frequency of the crankshaft, the centrifugal force of goods is small and they are held in force of springs. In this case, the distance between the cargo axes (on the slave halfway) and the leads the leading half will be maximal. The led part of the coupling lags behind the leading to the maximum angle. Consequently, the fuel injection advance angle will be minimal.

With an increase in the speed of rotation of the crankshaft of goods under the action of centrifugal forces, overcoming the resistance of the springs, diverge. Spacers slide according to the profile protrusions of goods and turn around the axes of the fingers of the cargo. Since the position of the spacer includes the heads of the leading half, then the discrepancy of goods leads to the fact that the distance between the leading half-one's fingers and the cargo axes will decrease, i.e. will decrease the angle of the ledge of the demummouft from the lead. The slave of the half is turned relative to the leading corner in the direction of rotation of the clutch (direction of rotation of the right). The rotation of the slave. The highway causes the cam shaft of the TNVD, which leads to an earlier fuel injection relative to the NWT.

With a decrease in the rotation of the crankshaft engine, the centrifugal power of goods decreases and they begin to converge under the action of the springs. The slave of the coupling is rotated relative to the drive leading, opposite to rotation, reducing the fuel injection advance angle.

The nozzle is designed for the fuel injection into the cylinders "of the engine, spraying and distribution of it in terms of the combustion chamber. On the KAMAZ-740 engine, closed-type nozzles with a multi-stage sprayer and a hydraulically controlled needle are installed. The pressure of the wave of the needle 20 ... 22.7 MPa (200 ... 227 kgf / cm2). The nozzle is installed in the cylinder head socket and the bracket is fastened. The sealing of the nozzle in the nest of the cylinder head is carried out in the upper belt with the rubber ring 7 (Fig. 48), in the lower-cone of the spray nut and the copper washer. The nozzle consists of the housing 6, the nuts of the sprayer 2, the sprayer, spacers 3, the rods 5, the springs, the support and adjusting washers and the nozzle fitting with the filter.

The housing of the nozzle is made of steel. In the upper part of the housing, threaded holes are made to install the fitting with the filter and the fiber of the drainage pipeline (see Fig. 37). The housing includes a fuel supply channel and a channel for removing fuel, seeping into the inner cavity of the case.

Fig. 48. Nozzle:
a - with adjusting washers; bs outdoor adjustment; 1 - dispenser housing; 2 - Nut of the Sprayer; 3 - spacer; 4 - installation pins; 5 - rod; 6 - body; 7 and 16 - sealing rings; 8 - fitting; 9 - filter; 10 - sealing sleeve; 11 and 12 - adjusting washers; 13 - Spring; 14 - spray needle; 15 - focus of the spring;. 17 - Eccentric

The nut the sprayer is designed to connect the sprayer with the nozzle housing.

Sprayer - nozzle assembly, spraying and forming jets of injected fuel.

The housing of the sprayer and the needle make up a precision pair, in which the replacement of one part is not allowed. The housing is made of chromonicheladium steel and subjected to special heat treatment (cementation, quenching, followed by deep cold processing) to obtain high hardness and wear resistance of working surfaces. In the spray case, the ring groove and a channel for supplying fuel into the cavity of the spray case, as well as two holes for the pins, ensuring the fixing of the sprayer body relative to the nozzle housing. At the bottom of the housing, four nozzle holes are made. Their diameter is 0.3 mm. To ensure a uniform fuel distribution by volume of combustion chamber, the nozzle holes are made at different angles. This is due to the fact that the nozzle relative to the axis of the cylinder is at an angle of 21 °.

The sprayer needle is designed to lock the spray holes after the fuel injection. The needle is made of instrumental steel and also subjected to special processing. In order to increase the service life of the sprayer and the needle, the valorist of the needle is doubled.

The spacer is designed to fix the dispenser's housing relative to the nozzle body.

The rod is a movable part of the nozzle, designed to transmit effort from the springs of the nozzle to the needle of the sprayer.

Spring nozzle is designed to provide the needle lifting pressure. The springs tension is carried out by adjusting washers, which are installed between the support washer and the end of the inner cavity of the nozzle body. The change in the thickness of the washers 0.05 mm leads to a change in the pressure of the beginning of the needle lifting by 0.3 ... 0.35 MPa (3 ... 3.5 kgf / cm2). In second-type nozzles (Fig. 48,6), the spring adjustment is made by turning the eccentric 17.

Joint work of the pump section of the pump and the nozzle. The driver, affecting the fuel pedal through the system of the thrust and levers, specifying the device of the all-life regulator, the rails of the fuel pump, the swivel sleeves, rotates the plunger. Thus, sets a certain distance between the cutting hole and the shut-off edge of the screw groove, providing a specific cycle fuel supply.

The plunger under the action of the cam shaft makes a reciprocating movement. When the plunger moves down the discharge valve, loaded by the spring, is closed and a vacuum is created in the admixture cavity.

After opening the upper edge of the plunger of the inlet in the sleeve fuel from the fuel channel under a pressure of 0.05 ... 0.1 MPa (0.5 ... 1 kgf / cm2) from the fuel-blowing pump enters the admixture space (Fig. 49, a).

At the beginning of the movement (Fig. 49, b) of the plunger Up the fuel part is displaced through the intake and shut-off holes in the fuel supply channel. The moment of the start of the fuel supply is determined by the moment of overlapping the inlet of the sleeve of the upper edge of the plunger. From this point on, when the plunger is moving up, the fuel is compressed in the admixture cavity, and after reaching the pressure at which the injection valve opens, in the high pressure pipeline and the nozzle.

Fig. 49. Scheme of the pump section:
a - filling of the admixture cavity; b - the beginning of the feed; in - end of filing

When the fuel pressure in the specified cavity becomes more than 20 MPa (200 kgf / cm2), the sprayer needle rises up and opens the fuel access to the nozzle holes of the sprayer, through which the fuel injection under high pressure in the combustion chamber occurs.

When the plunger moves up, when the cut-off edge of the screw groove reaches the level of the cut-off opening, the end of the fuel supply is occurring (Fig. 49, a). With the further movement of the plunger up the admixture cavity through the vertical channel, the diametrical channel, the screw groove is reported to the shut-off channel. As a result of this, the pressure in the admixture cavity drops, the injection valve under the action of spring and fuel pressure in the pump fitting sits in the saddle and the flow of fuel to the nozzle stops, although the plunger can still move up. With a decrease in the pressure in the fuel line below the force being created, the sprayer needle under the action of the spring is lowered down and overlaps the access of fuel to the nozzle holes of the sprayer, thereby terminating the fuel supply to the engine cylinder. Extraked through the clearance in a pair of needle - the body of the sprayer fuel is discharged through the channel in the housing of the nozzle to the drainage pipeline and then in the fuel tank.

Fuel system fuel gasoline engine ⭐ Designed for placement and cleaning of fuel, as well as cooking combustible mixture A certain composition and feeding it into cylinders in the required quantity in accordance with the engine operation mode (with the exception of direct injection engines, the power system of which provides the flow of gasoline into the combustion chamber in the required quantity and under sufficient pressure).

Petrol, like diesel fuel, is a product of oil distillation and consists of various hydrocarbons. The number of carbon atoms included in the gasoline molecules is 5 - 12. Unlike diesel engines in gasoline engines, the fuel should not be intensively oxidically oxidized during the compression process, as this may lead to detonation (explosion), which will adversely affect performance, efficiency and power Engine. The detonation resistance of gasoline is estimated by an octane number. The more it is, the higher the detonation resistance of the fuel and the allowable degree of compression. Modern gasolines, the octane number is 72-98. In addition to anti-knock durability, gasoline should also have low corrosion activity, low toxicity and stability.

Search (based on environmental considerations) alternatives to gasoline as the main fuel for DVS led to the creation of ethanol fuel consisting mainly of ethyl alcohol, which can be obtained from biomass of plant origin. The pure ethanol is distinguished (international designation - E100), containing exclusively ethyl alcohol; and a mixture of ethanol with gasoline (most often 85% ethanol with 15% of gasoline; designation - E85). In its properties, ethanol fuel approaches high-octane gasoline and even surpasses it octane number (more than 100) and calorific value. therefore this species Fuel can be successfully applied instead of gasoline. The only drawback of pure ethanol is its high corrosion activity that requires additional protection against the corrosion of fuel equipment.

To the aggregates and nodes of the supply system of the fuel of a gasoline engine are made by high demands, the mains of which are:

• tightness
• accuracy of dosing fuel
• reliability
• convenience in service

Currently, there are two main ways to prepare a combustible mixture. The first of them is associated with the use of a special device - a carburetor, in which the air is mixed with gasoline in a certain proportion. The basis of the second method is the forced gasoline injection in the intake manifold of the engine through special nozzles (injectors). Such engines are often called injection.

Regardless of the method of preparing a combustible mixture, its main indicator is the ratio between the mass of fuel and air. The mixture with its ignition should be burned very quickly and completely. This can be achieved only with good mixing in a certain proportion of air and gasoline vapor. The quality of the combustible mixture is characterized by a coefficient of excess air A, which is the ratio of the actual mass of air per 1 kg of fuel in this mixture, to theoretically necessary, providing full combustion of 1 kg of fuel. If 1 kg of fuel accounts for 14.8 kg of air, then this mixture is called normal (a \u003d 1). If the air is somewhat more (up to 17.0 kg), the mixture is depleted, and a \u003d 1,10 ... 1,15. When the air is greater than 18 kg and a\u003e 1,2, the mixture is called poor. Reducing the proportion of air in the mixture (or increase the share of fuel) is called it enrichment. At a \u003d 0.85 ... 0.90 mixture enriched, and when< 0,85 - богатая.

When a mixture of normal composition comes into the engine cylinders, it works steadily with average power and efficiency. When working on a depleted mixture, the engine power decreases somewhat, but its economy increases noticeably. On the poor mixture, the engine is unstable, its power drops, and the specific fuel consumption increases, so excessive depletion of the mixture is undesirable. When entering the cylinders of the enriched mixture, the engine develops the greatest power, but also fuel consumption is also increasing. When working on a rich mixture, gasoline burns with incompleteness, which leads to a decrease in the power of the engine, the growth of fuel consumption and the appearance of the soot in the graduation path.

Carburetor nutrition systems

Consider first carburetor systems Nutrition, which have recently been widespread. They are simpler and cheap compared to injection, do not require highly qualified maintenance during operation and in some cases are more reliable.

Fuel system of carburetor engine Includes fuel tank 1, coarse 2 and fine filters 4 fuel purification, fuel pumping pump 3, carburetor 5, inlet pipe 7 and fueling. When the engine is running, the fuel from the tank 1 using the pump 3 is fed through filters 2 and 4 to the carburetor. There, it is mixed in a certain proportion to be mixed with air from the atmosphere through the air cleaner 6. The combustible mixture formed in the carburetor in the intake collector 7 enters the engine cylinders.

Fuel tanks In power plants with carburetor engines, similar to the tanks of diesel power systems. Difference of the tanks for gasoline is only their best tightness, which does not allow gasoline to extort even when tipping the vehicle. For a message with the atmosphere in the lid of the filling tank, two valves - intake and outcomes are usually installed. The first of them provides an admission to the air tank as the fuel consumption, and the second, loaded by a stronger spring, is intended for a tank message with an atmosphere when the pressure is above atmospheric (for example, at high ambient air temperature).

Filters of carburetor engines Similar to filters used in diesel power systems. On trucks are installed lamellar-slot and mesh filters. For fine cleaning, cardboard and porous ceramic elements are used. In addition to special filters in separate units of the system there are additional filtering grids.

Fuel pumping pump It serves for forced gasoline supply from the tank to the float chamber of the carburetor. The carburetor engines typically use a diaphragm type pump with a drive from the camshaft eccentric.

Depending on the engine mode, the carburetor allows you to prepare a mixture of normal composition (A \u003d 1), as well as depleted and enriched mixtures. With small and medium loads, when you do not need to develop maximum power, you should prepare in the carburetor and serve a depleted mixture into the cylinders. With large loads (the duration of their action, as a rule, is small) it is necessary to prepare the enriched mixture.

Fig. Fuel System System Carburetor Engine:
1 - fuel tank; 2 - Fuel purification filter; 3 - fuel pumping pump; 4 - Fine cleaning filter; 5 - carburetor; 6 - air cleaner; 7 - intake manifold

In general, the carburetor includes the main dosing and starting device, systems idle move and forced idling, economizer, an accelerator pump, balancing device and a maximum speed limiter of the crankshaft ( trucks). The carburetor can also contain an eco-statue and high-altitude corrector.

Main dosing device Functions at all basic modes of engine operation in the presence of a vacuum in the diffuser of the mixing chamber. The main components of the device are a mixing chamber with a diffuser, a throttle valve, a float chamber, fuel jaw and spray tube.

Starting devicesabout Designed to ensure the start of a cold engine, when the frequency of rotation of the crankshaft-coated shaft is small and the vacuum in the diffuser is not enough. In this case, for a reliable start, it is necessary to submit a strongly enriched mixture into the cylinders. The most common starting device is the air damper installed in the receiving nozzle of the carburetor.

System of idle It is used to ensure the operation of the engine without a load with a low speed of the crankshaft rotation.

Forced idling system Allows you to save fuel while moving in engine braking mode, i.e., when the driver when the transmission is enabled, the accelerator pedal is released associated with the throttle of the carburetor.

Economizer Designed to automatically enrich the mixture when the engine is operated with full load. In some types of carburetors, except for the economizer to enrich the mixture use eco-stations. This device supplies an additional amount of fuel from the float chamber into a mixture only with a significant vacuum in the upper part of the diffuser, which is possible only with the opening of the throttle.

Acpercerative pump Provides a forced injection into a mixing chamber of additional fuel portions with a sharp opening of the throttle. It improves the engine pickup and TC, respectively. If there was no accelerator pump in the carburetor, then with a sharp opening of the damper, when the air flow rates rapidly, due to the inertia of the fuel, the mixture would be very impoverished at the first moment.

Balancing device It serves to ensure the stability of the carburetor. It is a tube connecting the receiving nozzle of the carburetor with an air cavity sealed (not communicating with the atmosphere) of the float chamber.

Maximum engine crankshaft rotation limiter Installed on carburetors of trucks. The most widely distributed limiter of a pneumatic centrifugal type.

Injector fuel systems

Injector fuel systems are currently used much more often carburetor, especially on gasoline engines. passenger cars. The gasoline injection in the intake manifold of the injection motor is carried out using special electromagnetic nozzles (injectors) installed in the head of the cylinder block and signal controlled from the electronic unit. This eliminates the need for a carburetor, since the combustible mixture is formed directly in the intake manifold.

There are single and multipoint injection systems. In the first case, only one nozzle is used to supply fuel (it is preparing a working mixture for all engine cylinders). In the second case, the number of nozzles corresponds to the number of engine cylinders. Nozzles are installed in the immediate vicinity of intake valves. The fuel is injected into finely sprayed form on the outer surfaces of the valve heads. Atmospheric air, fascinated in cylinders due to the vacuum in them during the inlet, flushes fuel particles from the valve heads and contributes to their evaporation. Thus, directly the fuel mixture is prepared directly from each cylinder.

In the engine with multipoint injection when power supply to the electric fuel pump 7 through the ignition lock 6 of gasoline from the fuel tank 8 through the filter 5 is supplied to the fuel ramp 1 (injector ramp), common to all electromagnetic nozzles. The pressure in this ramp is adjustable using a regulator 3, which, depending on the vacuum in the intake nozzle 4 of the engine, sends a part of the fuel from the ramp back to the tank. It is clear that all the nozzles are under one and the same pressure equal to the pressure of fuel in the ramp.

When it is necessary to submit (injection) fuel, into the winding of the nozzle electromagnet 2 from the electronic unit of the injection system for a strictly defined period of time the electric current is supplied. The core of an electromagnet associated with the nozzle needle, while retracts, opening the fuel path in the intake manifold. The duration of the supply of electric current, i.e. the duration of the fuel injection is regulated by the electronic unit. The electronic block program on each engine operation mode provides optimal fuel supply to cylinders.

Fig. Power system Scheme of a fuel of a gasoline engine with multipoint injection:
1 - fuel ramp; 2 - nozzles; 3 - pressure regulator; 4 - engine intake nozzle; 5 - filter; 6 - Ignition Castle; 7 - fuel pump; 8 - fuel tank

In order to identify the mode of operation of the engine and in accordance with it, calculate the duration of the injection, in the electronic unit Signals are served different sensors. They are measured and transformed into electrical pulses the values \u200b\u200bof the following engine operation parameters:

• throttle rotation angle
• the degree of permission in the intake manifold
• crankshaft rotation frequency
• the temperature of the suction air and coolant
• oxygen concentration in exhaust gases
• atmosphere pressure
• battery voltage
• and etc.

Petrol injection engines in the intake manifold have a number of indisputable advantages over carburetor engines:

• the fuel is distributed over the cylinders more evenly, which increases the engine efficiency and reduces its vibration, due to the absence of the carburetor, the resistance of the intake system is reduced and the cylinders filling improves
• it is possible to somewhat increase the degree of compression of the working mixture, since its composition in cylinders is more homogeneous
• the optimal correction of the composition of the mixture is achieved when switching from one mode to another
• provides best engine pickup
• in the exhaust gases contain less harmful substances.

At the same time, a number of shortcomings have a number of disadvantages in the intake manifold. They are complicated and therefore relative to expensiveness. Service of such systems requires special diagnostic devices and devices.

The most promising nutrition system of gasoline engines is currently considered a fairly complex system with direct gasoline injection into the combustion chamber, allowing the engine to work on a strongly depleted mixture for a long time, which increases its efficiency and environmental performance. At the same time, due to the existence of a number of problems of the system direct injection Not yet widespread.

Appearance carburetor:
1 - the heating block of the throttle zone;
2 - engine crankcase ventilation fitting;
3 - the cap of the accelerator pump;
4 - electromagnetic shut-off valve;
5 - carburetor cover;
6 - heel fastening air filter;
7 - air damper control lever;
8 - launching device cover;
9 - sector of throttle drive lever;
10 - the wire of the wire-screw sensor EPHH;
11 - adjusting screw of the amount of a mixture of idling;
12 - Economizer cover;
13 - carburetor housing;
14 - fuel supply fitting;
15 - fuel removal fitting;
16 - adjusting screw quality of a mixture of idling (by arrow);
17 - Fitting for feeding a vacuum ignition regulator

To work the engine, it is necessary to prepare a fuel mixture of air and fuel vapor, which should be homogenic, i.e. well mixed and have a certain composition to ensure the most efficient combustion. Power supply system of gasoline spark ignition It serves to prepare a combustible mixture and feed it into the engine cylinders and removal from cylinders of exhaust gases.
The process of preparing a combustible mixture is called carburation. For a long time, a unit was used as the main device for the preparation of a mixture of gasoline and air and feeding it into the engine cylinders, called the carburetor.

Principle of the simplest carburetor:
1 - fuel line;
2 - needle valve;
3 - hole in the cover of the float chamber;
4 - sprayer;
5 - air damper;
6 - Diffuser;
7 - throttle damper;
8 - mixing chamber;
9 - fuel jackler;
10 - float;
11 - Float Camera
In the simplest carburetor, fuel is located in a float chamber, where a constant level of fuel is supported. The float chamber is connected by the channel with a carburetor mixing chamber. There is a mixing chamber diffuser - Local narrowing of the camera. The diffuser makes it possible to increase the speed of the air passing through the mixing chamber. The most narrow part of the diffuser is derived sprayconnected by a channel with a float chamber. At the bottom of the mixing chamber is available throttle valvewhich turns when pressed by the driver of the "Gas" pedal.
When the engine works, air passes through the mixer of the carburetor. In the diffuser, the air velocity increases, and a vacuum is formed before the sprayer, which leads to a fuel flowing into the mixing chamber, where it is mixed with air. Thus, a carburetor, working on the principle of a pulverizer, creates fuel combustible mixture. By pressing the gas pedal, the driver turns the throttle of the carburetor, changes the amount of the mixture entering the engine cylinders, and therefore its power and turnover.
Due to the fact that gasoline and air have different density, when the throttle turn is rotated, not only the amount of combustion mixture supplied in the combustion chamber, but also the ratio between the amount of fuel and air in it. To complete the combustion of the fuel, the mixture should be stoichiometric.
When starting a cold engine, it is necessary to enrich the mixture, since the condensation of the fuel on the cold surfaces of the combustion chamber impair the starting properties of the engine. Some enrichment of the combustible mixture is required when working at idle, with the need to obtain maximum power, sharp accelerations of the car.
On the principle of its work, the simplest carburetor as the throttle openings it constantly enriches the fuel and air mixture, so it is impossible to use it for real engines cars. For automotive engines, carburetors with several special systems and devices are used: starting system (air damper), idle system, economizer or econostat, accelerating pump, etc.
As the requirements for saving fuel and reduce the toxicity of the exhaust gases, the carburetors became significantly complicated, even electronic devices appeared in the last variants of the carburetors.

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:

1. with distributed injection;
2. 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, the diesel power unit is represented 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 is not due to the spark plug (like a gasoline engine), but on the pressure generated by the cylinder piston, 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 movement. 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.

1. 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.
2. The composition of the mixture will be enriched with the use of the "idling" mode, which is used when "rolling" or the operation of the engine of the engine in a heated state.
3. 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).
4. The composition of the mixture will be enriched in full load mode when the car is moving at high speed.
5. 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

During the operation of the 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

Fault fuel system In this case, it is determined by a violation of the quality adjustment and the amount of combustible mixture entering 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 DVS modern car And responsible for timely and uninterrupted fuel supply to the power unit.