How are diesel nozzles arranged?

As you know, the internal combustion engine needs oxygen and fuel in a certain proportion. The process of supplying fuel differs from gasoline and diesel cars. In the latter case, injectors perform the role of injection. Diesel engines are equipped with different types of data elements. In today's article, we'll look at what the injectors are, what types they are and whether they are repairable.

Characteristic

So, let's start with the definition. The injectors of diesel engines are an element of the power system, which ensures the supply of fuel to the combustion chamber of the cylinder. The mechanism produces a torch spray of the mixture in the supernatant volume. Also diesel injectors produce fuel dosing. During operation, the element can open and close up to thousands of times per minute.

Types

There are several types of these mechanisms:

• Electrohydraulic.
• Piezoelectric.

How do these elements work in the diesel engine? Below we will consider the features of each of them.

Electrohydraulic

These injectors of diesel engines are installed on cars with a Common-Rail injection. The device of this mechanism assumes the presence of such elements:

• Control camera.
• Drain and inlet choke.
• Solenoid valve.

How do electrohydraulic diesel injectors work? Their algorithm of action is based on the use of fuel pressure during injection and its termination. So, in the initial state, the injector valve is closed and de-energized. And the needle of the mechanism is tightly pressed to the saddle under pressure of the fuel. In this position, the fuel is not injected into the cylinders. The injector is controlled from the electronics. A special control unit generates a signal that is sent to the solenoid valve. At this time, the drain nozzle of the diesel injector opens. Fuel flows through it and enters the drain line. The intake throttle blocks the rapid equalization of pressures in the intake manifold and control chamber. Then the needle rises against the saddle and the fuel enters the chamber. Then, from the force of pressure, it ignites, and a working stroke occurs. The nozzle itself returns to its original position. Then the cycle of the mechanism is repeated.

Piezoelectric

These injectors have a more refined design. The main advantage of piezoelectric injectors is their rapid response. The solenoid valve of the mechanism works four times faster than the hydraulic analogs. This makes it possible to produce multiple fuel injection in one cycle. The piezo nozzle is installed on the Common Rail system of the new generation. The control of this mechanism is based on changing the length of the piezoelectric crystal under a certain voltage. The design of piezoelectric injectors includes:

• Pusher.
• Needle.
• Switch valve.
• Piezoelement.

All this is housed in a small building. The principle of the element is based on the use of hydraulics. As in the previous case, the needle is seated on the saddle due to the fuel pressure. But as soon as the signal enters the mechanism, the length of the piezoelectric element increases. This opens the switching valve. Diesel fuel penetrates into the drain line. Needle due to high pressure, which formed in the lower part, rises. In this way, the fuel is injected. The compression, working stroke and release rates are the same. But the amount of diesel that is injected is determined by the fuel pressure in the fuel rail and the duration of the action on the piezoelectric element.

Repairs

The main elements that fail are:

• The multiplier. It is the main element of the "Bosch" nozzle. It consists of a rod and a saddle. The last element wears out and breaks. Also produced and stock. And if the saddle is restored, then repair of diesel injectors with a broken rod is not possible. This part is not subject to recovery. In this case, the multiplier is to be replaced.
• Spray. The manufacturer "Bosch" gives a guarantee for its trouble-free operation within one hundred thousand kilometers. But in our conditions the nebulizer nurses much less. He begins to wedge or pour fuel into the cylinder. How to solve this issue? In most cases, cleaning the diesel injectors with ultrasound helps (as they get dirty on our fuel). But if this operation does not help, the nebulizer changes to a new one.

Repair of diesel injectors may not be required by your car. It is enough to implement the correct adjustment. But preliminary check of diesel atomizers on the specialized equipment is carried out. The essence of the adjustment is simple. It consists in setting the course of the solenoid valve and the ball. The clearance is adjusted using the adjusting washers. Depending on the type of nozzle, the stroke of the ball element can be from 0.025 to 0.07 millimeters. After that, the valve stroke is set. It is worth noting that these operations are performed at specialized maintenance stations. At home, it is impossible to perform such an operation.

Conclusion

The nozzle is an important element of any diesel car. From its serviceability depends the work of the entire engine. Therefore, it is important to timely diagnose and, if necessary, repair diesel injectors. However, the arrangement of this mechanism does not allow the production of such works independently.