Operation Section
1
–
21
(4) Component Part Functions
Feed Pump
• The feed pump is a four-vaned type that draws fuel from the fuel tank and discharges it to the pumping mechanism.
The rotation of the drive shaft causes the feed pump rotor to rotate and the vane to move by sliding along the inner
surface of the casing (eccentric ring). Along with the rotation of the rotor, the pump draws fuel from the fuel tank, and
discharges it to the SCV and the pumping mechanism. To keep the vane pressed against the inner circumference, a
spring is provided inside each vane, in order to minimize fuel leakage within the pump.
Regulating Valve
• The purpose of the regulating valve is to control the feed pressure (fuel pumping pressure) sending fuel to the pump-
ing mechanism. As the rotational movement of the pump increases and the feed pressure exceeds the pressure set
at the regulating valve, the valve opens by overcoming the spring force, allowing the fuel to return to the suction side.
Component Parts Functions
Feed Pump Draws fuel from the fuel tank and feeds it to the pumping mechanism.
Regulating Valve Regulates internal fuel pressure in the supply pump.
SCV (Suction Control Valve) Controls the quantity of fuel that is fed to the plunger in order to control fuel
pressure in the rail.
Pumping
Mechanism
Inner Cam Actuates the plunger.
Roller Actuates the plunger.
Plunger Moves reciprocally to draw and compress fuel.
Delivery Valve Maintains high pressure by separating the pressurized area (rail) from the
pumping mechanism.
Fuel Temperature Sensor Detects the fuel temperature.
Check Valve Prevents the pressurized fuel in the pumping mechanism from flowing back
into the suction side.
Q000821E
Rotor
Eccentric Ring
Spring
Vane
Front Cover
Rear Cover
Regulating Valve
Open Valve Pressure Characteristic
Open Valve
Pressure High
Open Valve
Pressure Low
Speed
Feed Pressure
(Pumping Pressure)
Regulating Valve
Feed Pump
(Discharge Side)
Suction Inlet
Filter
Feed Pump
(Suction Side)
Regulating Valve Body
Spring
Piston
Bushing
Q000822E
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