|1–pipeline of return of fuel;
2–pipeline of supply of fuel;
3–fuel filter (high pressure);
|6–block of supply of fuel;
7–a quencher of pulsations (only on the TED engine);
9–cover of a toplivonalivny mouth;
11-the pipeline (to nozzles)
On the majority of fuel systems more than 90 % of fuel come back to a fuel tank in a normal operational mode.
The temperature of the fuel returned in a fuel tank raises on 7–15°С because it heats up passing under the bottom of the car and about the hot engine, and also at the expense of an internal friction and a friction about walls of pipelines.
Continuously returned warmed-up fuel increases fuel temperature in a tank.
In too time, the fuel compressed to pressure of 320-350 kPas in the fuel highway, passing through a pressure regulator, arrives in a fuel tank under small pressure.
In this case fuel evaporation, in relation to the elements having lower evaporation increases, and pairs of fuel arrive in a fuel tank.
Pairs of fuel from a fuel tank do not get to the atmosphere thanks to work of system of catching паров fuels.
System with the reduced return of fuel
On cars the system in which there is no pipeline of return of fuel from the engine in a fuel tank is established.
The pressure regulator established in a fuel tank and reduction of length of the pipeline of return of fuel, reduces fuel evaporation by 60–20 % in relation to usual fuel system.
Besides, installation of the jet pump in the block of supply of fuel, provides supply of fuel to the pump, providing steady supply of fuel, at low level of fuel in a tank. The system provides steady supply of fuel at car inclinations, at low level of fuel in a tank.
Block of supply of fuel
The block of supply of fuel is established in a fuel tank and consists of the following an element and knots:
– the fuel pump with an electric drive;
– pressure regulator;
– fuel filter;
– fuel level sensor;
The fuel pump with an electric drive is established in a fuel tank together with the fuel level sensor. The management of the fuel pump is made by the engine control unit, via the relay of the fuel pump.
The fuel pump via pipelines submits fuel under pressure to the fuel highway and nozzles. Pressure in the fuel highway remains even then when the fuel pump does not work, at the expense of the unilateral valve located about the fuel pump.
Regulator of pressure of fuel and nozzle
Pressure in fuel system is regulated by a pressure regulator.
Tension giving to nozzles is carried out from the storage battery via the main relay. The amount of the fuel submitted to an inlet path of the engine, is defined by duration of the impulses developed by the control unit by the engine and submitted on nozzles.
Fuel level sensor
The fuel level sensor consists of a float fixed on the lever and the variable resistor. At change of provision of a float, resistance of the variable resistor in proportion changes. On the basis of a signal from the fuel level sensor, the index of level of fuel in a combination of devices shows amount of fuel in a tank.
Fuel pipelines and hoses
Fuel pipelines and hoses provide fuel transfer from a fuel tank to the fuel highway and nozzles and return superfluous fuel in a tank. The fuel pipelines fixed on the bottom of the car are necessary for examining periodically on lack of dents and deformation as at the expense of narrowing of their passes, restriction of a stream of fuel is possible.
Fuel pipelines and hoses also provide transfer паров fuels from a fuel tank to the canister with absorbent carbon where they gather at the switched-off engine. After engine and warming up start-up to working temperature, the control unit the engine opens the electromagnetic valve, and pairs of fuel from the canister arrive in the engine and are burned.
The fuel highway provides supply of fuel to each nozzle and is established on an inlet collector.
Now, the regulator of pressure of fuel is not located on the fuel highway, and established in a fuel tank.
On the fuel highway the service valve which serves for air removal after service of the car or engine start-up is located.