Add: Mechanical&Electrical Industry Zone,Yuhuan,Zhejiang,China
Fuel pump is a professional term for the auto parts industry. It is one of the basic components of the fuel injection system of the EFI vehicle. It is located inside the vehicle fuel tank. The fuel pump works when the engine is running and the engine is running. If the ignition is still ON when the engine is stopped, the HFM-SFI control module turns off the power supply of the fuel pump, To avoid accidental ignition.
Fuel pump is the role of the fuel from the fuel tank, the pressure sent to the oil supply pipe, and fuel pressure regulator with the establishment of a certain fuel pressure.
Fuel pump by the electric motor, pressure limiter, check valve composition, electric motor actually work in the oil pump shell fuel, do not worry, because the shell does not have anything to ignite things, fuel can lubricate and cool the fuel motor, Is equipped with a check valve, the pressure limiter is located on the pressure side of the oil pump housing, with a passage leading to the inlet port.
When the rotor disc rotates, the roller is centrifugal force outward pressure, like rotating oil seal, the rotor rotation, pump function, from the inlet into the fuel, and the fuel from the oil into the fuel system, when the oil pump off , The oil port of the check valve closed to prevent fuel flow through the fuel pump back to the tank, check the valve to maintain the fuel pipe pressure as "residual pressure."
The maximum pump pressure of the fuel pump depends on the pressure limiter's standard. If the fuel pump pressure exceeds the predetermined pressure limit, the pressure limiter opens the bypass to return the fuel to the fuel pump inlet.
An electric fuel pump is a device that continuously sucks fuel from a fuel tank and provides fuel and fuel to a fuel system. Based on the function of electric fuel pump can be said that the performance of electric fuel pump will directly affect the performance of the engine performance. 
The electric fuel pump is the "heart" of the fuel supply system of the EFI engine. There are two kinds of electric fuel pump in the oil supply system, one is external, that is, fuel pump in series outside the tank in the pipeline; the second is built-in, that is, fuel pump installed in the fuel tank, immersed in gasoline, This fuel pump is easy to heat, work noise, long life, so the application is more extensive.
The electric fuel pump is composed of three parts: pump body, DC motor and shell. Its basic working principle is driven by the DC motor drive the pump body when the rotor for high-speed rotation, the rotor shaft at the bottom of the cut surface and the impeller bore section of the combination, so that when the rotor rotation through the rotor shaft to drive the same rotation with the impeller, Impeller high-speed rotation process in the inlet part of the vacuum caused by a part of the vacuum, and then filtered through the pump from the inlet of the pump, the inhalation of fuel through the fuel pump impeller pressure into the pump shell and then through the oil pressure Out of the fuel system to provide a certain pressure of fuel. The structure of the DC motor includes a permanent magnet fixed to the inner wall of the pump housing, a rotor capable of generating a magnetic moment upon energization, and a graphite carbon brush assembly mounted at the upper end of the pump casing. The carbon brush and the armature rotor commutator in the elastic contact state, the lead connected to the shell of the plug-in electrode, electric fuel pump pump shell at both ends of the outer edge of the use of curling riveting tight, as a non-removable assembly
(1) electric fuel pump internal parts (such as roller-type fuel pump plunger and cylinder) with the very precise, so the key to extend the life of the fuel pump is to keep the fuel clean, and in accordance with the use of maintenance requirements of regular cleaning All the filter (note that it can not be cleaned with a fiber cloth) to prevent the fuel pump from being impaired by impurity or early wear.
(2) For built-in electric fuel pump, to prohibit the fuel tank in the case of forced start the engine. Remove the fuel pump from the tank to do the test, each time the power can not be more than 6s, because no gasoline cooling time is too long, easily lead to fuel pump motor windings burned.
(3) As the electric fuel pump is the overall package type, are irreparable parts, in the event of damage, should replace the same type of fuel pump. If the replacement of the fuel pump model is different, may be due to pump oil pressure can not meet the original requirements caused by performance disorders.