LR3/Disco 3
The HP fuel from the fuel-rail passes through the HP connection (2) into the control chamber (11) and into the HP
chamber (10) of the fuel injector nozzle.
The piezo actuator (1) is currentless and the valve mushroom (12) closes the bore to the fuel return (7) by means of
spring pressure.
There is how ever a continuous fuel return (6) to vent internal leakage within the injector.
The hydraulic force (3), which is now applied on the control piston by the fuel under high pressure in the control chamber
(11) through the control piston (8), is greater than the hydraulic force (4) acting on the tip of the nozzle (since the area of
the control piston in the control chamber is greater than the area of the tip of the nozzle).
Fuel Injector Actuated (Injecting Fuel)
Item Part Number
Description
1
-
Piezo actuator
2
-
HP connection
3
-
Hydraulic force applied on control piston
4
-
Hydraulic force acting on tip of nozzle
5
-
Control piston
6
-
Fuel return
7
-
Fuel return
8
-
Control piston
9
-
Nozzle needle
10
-
High pressure chamber of nozzle
11
-
Control chamber
12
-
Valve mushroom
Item Part Number
Description
1
-
High pressure supply
2
-
Valve piston
