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1 electric fuel pump
Introduction:
Note: EFI car fuel pump, mounted in the tank, immersed in the fuel, i.e., the electric fuel Pump.
Function: the pressurized gasoline, and a steady stream into the pump supply conduit.
The supply of the excess oil to the oil pan in order to maintain the working pressure injection system: usually installed in the vicinity of the tank.
electric fuel pump structure and working principle:
using a variety of modern cars in gasoline injection system, their fuel supply means are different, but it must be safe electric fuel pump. Its main task is to supply enough fuel system and there is a certain pressure of fuel.
Since the mechanical diaphragm type fuel pump, by the structural limitations, the installation position of the heat away from both in-line and also not fixedly mounted transversely. And an electric fuel pump can be arbitrarily selected position, and having no gas barrier characteristics.
configuration of the electric fuel pump of the pump consists of three parts, consisting of the permanent magnet motor and the housing. I.e., the permanent magnet motor is energized to drive the rotary pump, the fuel sucked from the oil inlet through the internal electric fuel pump, then pressure oil from the mouth, the supply of fuel supply system. Fuel flows through the internal electric fuel pump, a cooling effect on the permanent magnet motor armature, also known as wet fuel pump.
partially electric fuel pump motor comprises a permanent magnet and fixed to the casing of the electromagnetic torque of an armature and a brush mounted on the housing means. Commutator on the armature in contact with the brush, its leads connected to the column housing, a control voltage for the electric fuel pump is directed to the armature winding. Both ends of the electric fuel pump housing rivet bead, the respective components are assembled into a non-removable cartridge.
Additional fuel pump function is accomplished by a safety valve and a check valve. When blocked fuel line pressure relief valve to avoid excessive rises,Caused pipeline rupture or the fuel pump damage occurred. Purpose-way valve, to the fuel pump is stopped when the oil seal, so to maintain a certain residual pressure fuel system, so that the next start the engine easily.
is the main pump electric fuel pump oil, according to their different structure and the separable roller vane plate. The most common roller electric fuel pump. Electric fuel pump is installed in the vehicle mounted outside the fuel tank and fuel tank outside. There are a few models in the fuel tank, outside of the installation of an electric fuel pump, oil on the road in both series.
Different types of electric fuel pump:
(1) electric fuel pump roller:
by the housing, the cylindrical rollers and rotors and other components. Five rollers in the grooves of the rotor radially slidable, there is a certain eccentricity of the rotor and the housing. A DC motor driving the rotor in rotation, the centrifugal force of the roller pressed against the inner peripheral surface of the pump body, forming five independent sealed chamber. When rotating, the volume of each sealing chamber is changing, at the intake port, the volume is increased, a certain vacuum, the filtered gas suction pump. At the outlet of the oil, small volume, pressure increases, the DC motor gasoline through the open check valve output. When blocked or clogged fuel filter pipeline path occurs, gas pressure exceeds a predetermined value, the pressure limiting valve is opened, gas flows back into the oil side. Engine flameout.
(2) fuel pump leaves the formula:
The vane pump rotor vane groove and the pump housing (stator rings) contact the liquid pressure from the suction side to the discharge of oil into the oil pump side.
(3) fuel pump gear:
The gear pump is a positive displacement pump, the two gears, pump and front and rear cover consisting of two enclosed space, when the gear rotates, volume of the disengagement-side gear space becomes large from small vacuum is formed, the liquid suction, gear side from the volume of the space into small, but the liquid line to squeeze. The suction chamber and the discharge chamber is by two gears meshing line to spaced.
How to check the electric fuel pump is normal:
Loosen the carburetor inlet pipe fittings, electric fuel pump brought back to force the hand of the rocker arm with fingers position, the engine crankshaft is rotated slowly, the rocker arm and from the handTo finish a work trip. If the stroke is small, electric fuel pump can work to maximum stroke (the maximum eccentricity of the eccentric cam top rocker arm), and then forced rocker hook hands, should feel a little reserve travel. If there is no stroke engine described in conjunction with the pump face of the pad is too thin; if the stroke is too large, or too thick then the gasket inner rocker arm wear, should be adjusted or repaired.