Injectors for diesel engines- these are the details fuel equipment, which are most susceptible to wear. They are considered the easiest to maintain and perform diagnostics in service centers. The quality of fuel combustion in the engine cylinders, its starting, vehicle acceleration dynamics, efficiency and the amount of harmful emissions depend on how efficiently the injectors work.

Injectors for diesel engines - what are they?

Depending on the type of nozzles and fuel system maximum pressure diesel engine injectors in the atomizer at the moment of injection is about 200 MPa, and the time is from 1 to 2 milliseconds. The quality of injection determines the engine noise level, the amount of emissions of soot, nitrogen oxides and hydrocarbons into the atmosphere.

Modern models differ in the shape of the body, the size of the nozzles, and also in the control method. Difference various types injectors consists of using various systems injection and types of nozzles, which are pin and hole. Pin ones are used in engines with a pre-chamber ignition system, while hole type ones are installed on diesel engines with direct fuel injection.

According to the control method, parts are divided into single-spring, double-spring, with needle position control sensors and controlled by piezoelectric elements. Among other things, the design of a diesel engine injector depends on the method of its installation in the head: using a flange, a clamp, or by screwing it into a socket.

The principle of operation of a diesel engine injector - briefly about the complex

The main purpose of such parts is to meter and atomize fuel, as well as hermetically seal the combustion chamber. As a result of research, pump injectors were developed, which are installed in each cylinder separately. The operating principle of the new type of diesel engine injector is that it operates from a cam camshaft through the pusher. Fuel is supplied and drained through special channels in the cylinder head. Fuel dosing occurs through the control unit, which sends signals to the shut-off solenoid valves.

The pump injector operates in pulse mode, which allows for preliminary fuel supply before the main injection. As a result, engine operation is significantly softened and the level of toxic emissions is reduced.

Fuel injectors in most cases require simple maintenance, most often in order to return them to working condition, you just need to clean and rinse them. No matter how many injectors there are in the engine, it happens that when sharp pressing jerks and dips are felt on the gas pedal or the power is noticeably reduced, the engine begins to operate unstably low revs, this means that the nozzle channels are clogged with hard tar deposits. What to do?

Flushing diesel engine injectors - implementation methods

Contamination of this element leads to disruption of fuel atomization and leads to incorrect formation air-fuel mixture . Ideally, spraying should be as uniform as possible. The main source of pollution is the resins contained in the fuel. Flushing diesel engine injectors can eliminate all fuel supply problems.

The injector cleaning process involves removing various contaminants in fuel channels. Currently, several methods are used:

• cleaning diesel engine injectors using ultrasound;
• flushing injectors with fuel with the addition of special additives;
• washing using special liquids on stands;
• hand washing.

For motorists, the last option is the most acceptable, since it allows you to carry out work on cleaning injectors at home. However, in advanced cases, you have to turn to the services of auto centers, where cleaning is carried out using ultrasound, which is a more severe method. TO this species It is recommended to resort to cleaning only if washing with special liquids does not give a positive result.

Some people have no idea what a car fuel injector is. And those who have certain information about it are mostly unfamiliar with the principles of its operation and purpose. This item is an integral part of the fuel system auto vehicle. The fuel injector performs the delivery functions required quantity fuel into the combustion chamber of the machine engine itself. The nozzle design ensures mixing of diesel fuel and air, creating a combustible mixture. In this article we will try to understand what a nozzle is, why it is needed, and so on. Also for clarity, photos are provided.

What is a nozzle for?

According to the statement, the main function assigned to the part, the nozzle, is the timely supply of the fuel mixture to the combustion chamber under a certain pressure. The mixture composition varies depending on the engine type: gasoline unit needed accordingly gasoline mixture, and diesel is based on air and diesel fuel. Before fuel enters the combustion chamber itself, a certain amount of fresh air and fuel are mixed. This mixture is then transported to the combustion chamber.

To move the mixture through fuel system it is necessary to build up pressure using a special valve, which, when opened, takes in fuel and pushes the resulting mixture into the cylinders.

Today you can find enough big variety injectors, which differ in valve drive and operating principles. Note that the most common auto injectors are those with a so-called solenoid valve. It is usually installed on gasoline internal combustion engines due to the simplicity of its design and operating technology. The only caveat is that they should be washed periodically.

The fuel injector operates on the basis of signals transmitted by the electronic control unit, which instruct a special winding located on the injector body to create a vacuum at a specific moment to receive a designated amount of gasoline directly in the engine combustion chamber.

IN specified time, the injector needle comes out of seat and squeezes the required volume of fuel under pressure into the combustion chamber. The number of atmospheres in the fuel rail is always constant. As power increases, more fuel is pumped into the engine at higher pressure, which is pumped automatically.

The second class of nozzle is with an electro-hydraulic drive. Such a fuel injector is usually located on diesel internal combustion engines. This device operates according to signals electronic unit, which determines the engine's fuel requirement. In this case, the combustion chamber is filled with diesel fuel due to the pressure difference between piston group. Now it’s more clear what a group 2 injector is.

What is a group 3 injector? It is less common and is installed on diesel engines with a fuel supply system Common Rail. They are better in terms of pressure buildup and speed of response to control input. Therefore, throughout the entire cycle, fuel enters directly into the combustion chamber under a certain constant pressure, which has a good effect on power. The driving force is carried out by hydraulics, as in the second type of nozzle. This is shown in various photos.

We make replacements and repairs

It was previously indicated that clogging occurs periodically, which limits the supply of fuel to the power unit. The fuel injector must be clean and working properly. To maintain engine performance, you should carry out regular prevention and cleaning.

Refueling high-quality gasoline from trusted dealers will reduce the likelihood of nozzle clogging. These channels ensure the movement of fuel from the tank into the combustion chambers of the vehicle's power plant. To protect the machine from fuel Low quality The vehicle design provides for the presence of various filter elements that are located throughout the fuel system. Filters perform fine and coarse cleaning. Filter rough cleaning used when pouring gasoline into the tank, and the filter soft cleaning installed in close proximity to the injection system.

You can now find a wide variety in auto stores. detergents. They are used when cleaning jets. Such additives are poured into the fuel tank, after which they independently clean the channels.

This approach can be used when the level of contamination of the nozzles is insignificant. If the degree of blockage is such that it does not allow the car to start, then a more effective method should be used.

Another method of getting rid of contamination is to clean components without dismantling them. To do this, you need to pour the flushing mixture into the fuel located in the refueling tank. Afterwards, remove the fuel pump and supply pipes. Next, the supply line is connected to a blowdown unit, which will clean the channel. It will flush under high pressure with a flushing mixture inner part pipe

The last method of cleaning a fuel injector is used when the first two are ineffective. In this case, the injectors are removed from the engine and immersed in a special compound in a special container. Cleaning takes place in this chamber using ultrasound. It destroys foreign particles in the body of the element.

For prevention, it is necessary to add flushing fluid every 2000-3000 km. They clean both the jets and the fuel supply system and components that are prone to clogging. You should also maintain a special fuel pump, which is responsible for supplying gasoline to the pipeline, where the pressure is always controlled.

Let's sum it up

Every modern car enthusiast has a certain idea about the fuel system, however, not everyone performs proper maintenance and adheres to the operating rules. Quite often, car service centers are replenished by representatives of the auto industry with a contaminated fuel system of the car. The fuel injector must always be clean and working properly. To prevent such a situation, proper care of the machine is necessary.

The fuel injector (FF), or injector, refers to the parts of the fuel injection system. It controls the dosing and supply of fuel and lubricants with its subsequent spraying in the combustion chamber and combining with air into a single mixture.

TFs act as the main executive parts related to the injection system. Thanks to them, the fuel is divided into small particles by splashing and enters the engine. Injectors for any type of engine serve the same purpose, but differ in design and operating principle.

This type of product is different individual production for a specific type of power unit. In other words, there is no universal model of this device, so rearranging them with gasoline engine You can't use diesel. As an exception, we can give an example of hydromechanical models from BOSCH installed on mechanical systems, operating on continuous injection. They find wide application for various power units as component element K-Jetronic systems, although they have several modifications that are not related to each other.

Location and principle of operation

Schematically, an injector is a software-controlled solenoid valve. It ensures that fuel is supplied to the cylinders in prescribed doses, and the installed injection system determines the type of products used.

Fuel is supplied to the injector under pressure. In this case, the engine control unit sends electric pulses to the injector electromagnet, which activate the needle valve, which is responsible for the state of the channel (open/closed). The amount of incoming fuel is determined by the duration of the incoming pulse, which affects the length of time the needle valve remains open.

The location of the injectors depends on the specific type of injection system:

Central - placed in front throttle valve in the intake manifold.

Distributed - all cylinders have a separate nozzle located at the base intake pipe and performing fuel injection.

Direct – the injectors are located at the top of the cylinder walls, which provides injection directly into the combustion chamber.

Injectors for gasoline engines

Gasoline engines are equipped with the following types of injectors:

Single-point - supplies fuel, located before the throttle valve.

Multipoint - several nozzles located in front of the pipelines are responsible for supplying fuel and lubricants to the cylinders.

TFs ensure the supply of gasoline to the combustion chamber of the power plant, while the design of such parts is non-separable and does not allow for repairs. They are cheaper in cost than those installed on diesel engines.

As a part that ensures the normal operation of a car's fuel system, injectors often fail due to contamination of the filter elements located on them with combustion products. Such deposits block the spray channels, which disrupts the operation of a key element - the needle valve - and interrupts the flow of fuel into the combustion chamber.

Injectors for diesel engines

Correct operation of the fuel system of diesel engines is ensured by two types of injectors installed on them:

Electromagnetic, the operation of which is controlled by a special valve that regulates the raising and lowering of the needle.

Piezoelectric, hydraulically operated.

The correct setting of the injectors, as well as the degree of their wear, affects the operation diesel engine, the power it produces and the volume of fuel consumed.

Breakdown or malfunction diesel injector The car owner can notice a number of signs:

Increased fuel consumption at normal traction.

The car does not want to move and smokes.

Methods for cleaning injectors

To solve the above problems, periodic flushing is required. fuel injectors. To remove contaminants, ultrasonic cleaning is used, a special liquid is used, performing the procedure manually, or special additives, allowing you to clean the injectors without disassembling the engine.

Pouring flushing into the gas tank

The simplest and most gentle way to clean dirty injectors. The principle of operation of the added composition is to constantly dissolve existing deposits in the injection system with its help, as well as partially prevent their appearance in the future.

This technique is good for new cars or cars with low mileage. In this case, adding flushing to the fuel tank acts as a preventive measure that allows you to maintain power plant and the vehicle's fuel system is clean. For vehicles with severe contamination of the fuel system this method is not suitable, and in some cases can cause harm, aggravating existing problems. If there is a large amount of contaminants, washed away deposits enter the nozzles and clog them even more.

Cleaning without removing from the engine

Flushing the TF without disassembling the engine is performed by connecting the flushing unit directly to the motor. This approach allows you to wash off accumulated dirt on the injectors and fuel rail. The engine is started for half an hour Idling, the mixture is supplied under pressure.

This method is not widely used worn out engines and is also not suitable for vehicles with installed system KE-Jetronik.

Cleaning by removing injectors

In case of severe contamination, the engine is disassembled on a special stand, the injectors are removed and they are individually cleaned. Such manipulations additionally make it possible to determine the presence of malfunctions in the operation of the injectors and their subsequent replacement.

Ultrasonic cleaning

Cleaning of injectors is carried out in an ultrasonic bath for previously removed parts. This option is suitable for severe stains that cannot be removed with a cleaner.
Operations to clean injectors without removing them from the engine on average cost the car owner 15-20 USD. The cost of diagnostics followed by cleaning for one nozzle in ultrasound or on a stand is about 4-6 USD. Complex works for washing and replacing individual parts allow us to ensure uninterrupted operation fuel system for another six months, adding 10-15 thousand km. mileage

Designed for dosed supply of fuel, its atomization in the combustion chamber ( intake manifold) and the formation of a fuel-air mixture.

The injector is used in injection systems of both gasoline and diesel engines. On modern engines nozzles are installed electronically controlled injection.

Depending on the method of injection, the following types of nozzles are distinguished: electromagnetic, electrohydraulic and piezoelectric.

Electromagnetic injector

An electromagnetic injector is installed, as a rule, on gasoline engines, incl. equipped with a direct injection system. The nozzle has a fairly simple device, including a solenoid valve with a needle and a nozzle.

The operation of the electromagnetic injector is carried out as follows. In accordance with the established algorithm, the electronic control unit provides right moment supplying voltage to the valve excitation winding. This creates an electromagnetic field, which, overcoming the force of the spring, retracts the armature with the needle and releases the nozzle. Fuel injection is in progress. With the disappearance of tension, the spring returns the injector needle to the seat.

Electrohydraulic nozzle

The electrohydraulic injector is used on diesel engines, incl. equipped with a common rail injection system. The design of the electro-hydraulic injector combines a solenoid valve, a control chamber, inlet and return throttles.

The operating principle of the electro-hydraulic injector is based on the use of fuel pressure, both during injection and when it is stopped. IN starting position the solenoid valve is de-energized and closed, the injector needle is pressed to the seat by the force of fuel pressure on the piston in the control chamber. Fuel injection does not occur. In this case, the fuel pressure on the needle, due to the difference in contact areas, is less than the pressure on the piston.

At the command of the electronic control unit, the solenoid valve is activated, opening the drain throttle. Fuel flows from the control chamber through the throttle into the drain line. In this case, the intake throttle prevents the rapid equalization of pressures in the control chamber and the intake manifold. The pressure on the piston decreases, but the fuel pressure on the needle does not change, under the influence of which the needle rises and fuel is injected.

Piezoelectric injector

The most advanced device that provides fuel injection is a piezoelectric injector (piezo injector). The nozzle is installed on diesel engines, equipped with a Common Rail injection system.

The advantages of a piezo injector are the speed of response ( 4 times faster than solenoid valve), and as a consequence the possibility of multiple fuel injections during one cycle, as well as precise dosage of injected fuel.

This was made possible thanks to the use piezoelectric effect in injector control, based on changing the length of a piezocrystal under the influence of voltage. The structure of a piezoelectric injector includes a piezo element, a pusher, a switching valve and a needle placed in a housing.

The piezo injector, like the electro-hydraulic injector, uses the hydraulic principle. In the initial position, the needle is seated on the seat due to high fuel pressure. When an electrical signal is applied to the piezoelectric element, its length increases, which transmits force to the pusher piston. The switch valve opens and fuel flows into the drain line. The pressure above the needle drops. The needle rises due to pressure in the lower part and fuel is injected.

The amount of fuel injected is determined by:

• duration of exposure to the piezoelectric element;
• fuel pressure in the fuel rail.

An automobile injector is a device that is responsible for directly spraying fuel inside the combustion chamber. And not only the power of the car, but also fuel consumption depends on how its design is arranged and the coherence of each mechanism.

Essentially, this is a miniature pump with the help of which fuel ( fuel mixture) reaches its final destination, where it is converted into energy. At the initial stage, you now understand what an injector is in a car and what functions it performs. Let's move forward.

Today these devices are made in various modifications, each of which has its own advantages. Specifically, these are mechanical, electromagnetic injectors, followed by piezoelectric, as well as electrohydraulic.

Basic information about the injector

The design features of the injectors are determined by their main task - precise, constant dosing required quantity fuel supplied to the combustion chamber. The pressure created in the injector is directly dependent on the type of fuel that passes through it. It can be at a level of 200 MPa, while remaining for a short period of time (which is about 1-2 milliseconds).

Not all injectors have a standardized appearance. They differ from each other in shape, spray method, size of spray elements, and process control procedure. Here it is important to note the difference in injection systems used for various types and types of equipment. The most common nozzles are pin nozzles, used in conjunction with the prechamber ignition system, as well as perforated nozzles, typical for engines running on diesel fuel.

It's important to note that internal mechanism also directly depends on the method of controlling the injectors. They can be single spring, or double spring using special control sensors.

In addition to atomizing fuel, the injector must provide a seal to the combustion chamber so that the engine does not lose power during operation. To achieve this, modern developers are introducing various tricks and rational proposals, with the help of which two or more degrees of fuel pumping are introduced. But general fuel control is carried out using a special control unit that controls solenoid valves fuel supply.

Now, a little more specific data about the real benefits of injectors and their role in ensuring the operation of the car. First of all, this device is the main connecting element between the engine and fuel pump. Their purpose can be described as follows:

— ensure the correct dosage of fuel supplied to the engine;

— ensure the correct flow (angle, pressure, quantity) of the mixture, as well as its preparation;

- mediation between common system formation and injection and combustion chamber;

— maintaining the correct release rate curve.

The design features of the injectors directly depend on the specific modification and control method (mixture supply). But piezoelectric injectors are considered the most effective, rational and practical today. Their advantage is the possibility of multiple injections in one cycle, as well as the speed of response.

The most common problems that cause contamination of the fuel supply device and further car begins to “act up”, is the appearance of deposits on the walls of the injectors, formed due to the use of low-quality fuel or with various impurities of fuel. All this can cause interruptions in operation, increased fuel consumption, and causeless loss of power.

To avoid this, it is necessary to periodically flush the fuel injectors.

Determining the beginning of problems is quite simple. They can be seen by the following basic characteristics:

— during the engine starting process, unplanned failures begin;

— the amount of fuel consumed has become significantly higher than the nominal (normal) consumption;

— exhausts began to have an uncharacteristic black color;

— engine operation is marked by tripling (doubling);

- when the engine is on idle speed There are frequent failures of its functioning in a rhythmic and uninterrupted mode.

Usually, special labor In this case, the problem cannot be solved. To do this, you just need to rinse, clean and install the nozzle in its original position. It is important here to remove all contaminants that caused the failure.

You can do this:

- using special liquid independently by hand;

— ultrasonic cleaning;

— by adding special cleaning additives to the fuel (without disassembling the engine);

- on a special stand, using a special cleaning liquid.

The choice of cleaning method directly depends on the degree of contamination of the device and the problems that arise when starting the engine. What is important here is the time when you “came to your senses” and decided to fix the problem. The earlier it is, the less time-consuming and costly a cleaning method can be selected.

In practice, cleaning with additives or at home manually is most often used. These are the cheapest and simple ways cleaning. If the car goes to a special service, then they can use cleaning at a stand, or with ultrasound. The last cleaning method is considered the most severe and is advisable in cases where the nozzle has very strong contamination that cannot be washed with ordinary liquid.