Diesel fuel in cars can burn only under certain conditions that provide high pressure. Therefore, in machines with a diesel engine, a high-pressure fuel pump (abbreviated as high pressure fuel pump) is used. What is this node, what is its principle of operation, what is its role in general? Every motorist should know this. Now let's talk about what this injection pump is, what function it performs.
TNVD: what is it
The fuel pump is an extremely complex unit from a constructive and technical point of view, which ensures the supply of diesel fuel to the engine combustion chamber. The system does this automatically: under a certain pressure at the right time. However, the most accurate formulation of the functioning of the injection pump is its ability to create a high pressure diesel engine, at which it burns out in full. The process contributes to an increase in engine power.
The principle of operation of the fuel pump
The diesel engine itself is a complex mechanism, the efficient operation of which depends on the fuel pump. Interested in the question of what are high-pressure fuel pumps in diesel engines? The principle of operation is to create a pressure of more than 150 MPa. It is worth noting that this is a high bar, which, in order to achieve, the injection pump must meet a number of requirements. One of them is high quality material. Succumbing to high loads and temperature fluctuations, the pump must first be heavy-duty and reliable. For this, manufacturers use special aluminum alloys AL9. High demands are also placed on the plunger pair of the cylinder and the rod. Parts must be made of high-strength steel that can withstand high loads.
Varieties of injection pump
Diesel engines differ from each other in models, even generations. Accordingly, each type of engine needs a suitable fuel pump, which is why they are usually classified according to a number of criteria:
- Row injection pumps. A feature of the mechanism is plunger pairs for each cylinder. Despite the location in the same row, diesel is supplied through different channels to the spray nozzles. When starting, the rotation of the motor is transmitted to the camshaft. Under the influence of the cams, the elements of each plunger pair begin to move. This causes the plungers to move through the cylinder, compressing air at high temperature. When the compressed air pressure exceeds a certain level, the inlet valve is activated. Through its hole, sawn diesel fuel enters the combustion chamber. In-line injection pumps have found their application in large or trucks. They have proven to be durable and reliable systems.
- Distribution injection pumps. The amount of diesel is regulated by several plungers. Fuel is supplied through the distributor head and channels. Such injection pumps owe their popularity to their small dimensions and relatively low weight, which allows them to be used in passenger cars. In addition, the fuel is constantly supplied with the same power.
- Main high pressure fuel pumps in a car. Answering the question of what a fuel injection pump is in a car, let's say that all modern cars with a diesel engine are equipped with such a unit. The main difference lies in the supply of diesel fuel directly to the ramp, which acts as a storage tank. The design of the pump usually consists of a different number of plunger pairs. They begin to move under the action of individual spring elements, compressed air or hydraulics.
The most common causes of fuel pump failures
Continuing the conversation about what a fuel injection pump is in a car, it is worth saying that there are many potential reasons for its failure. However, the main cause of fuel pump failures is the use of poor quality fuel. However, this applies not only to diesel engines, but also to gasoline ones. In the entire assembly design, the plunger pairs are the most vulnerable. The slightest abrasions found on them indicate the incorrect operation of the entire high-pressure fuel pump.
If you understand what a high-pressure fuel pump is on a diesel engine and breakdowns of this element, it is important to say that you can accurately determine the cause of a malfunction only at a service center, at a stand. You can independently determine that there is a problem with the pump by the following signs:
- increased fuel consumption;
- engine malfunctions even at low speeds;
- inability to start the car the first time;
- overheating of the assembly and engine, respectively;
- diesel leak detection;
- decrease in motor power;
- black exhaust fumes;
- knocking or any other extraneous sounds in the motor.
If we conclude what a high-pressure fuel pump is in a car, it is worth saying that it is an indispensable unit, the analogues of which have not yet been invented. For all the years of its existence, manufacturers have practically not changed anything in its design, but only improved individual parts. The question of why a high-pressure fuel pump is needed in a car can be compared with the question of why a person needs a heart. Summarizing, we can answer that this is a unit that ensures uninterrupted circulation of fuel through the fuel system, regulates the amount of fuel supplied depending on the load, pumps diesel into the injectors, and determines the exact moment of fuel injection into the cylinder.