User Manual

Fill
Cross section of fill cycle
(1) Solenoid
(2) Armature spring
(3) Armature
(4) Seated pin
(5) Spool spring
(6) Spool valve
(7) Check ball for intensifier piston
(8) Intensifier piston
(9) Return spring
(10) Plunger
(16) Check piston
(18) Reverse flow check valve
(19) Nozzle check
(22) Drain
The fill cycle begins when the solenoid (1) is de-
energized. The armature (3) and the seated pin (4) are
forced down by the armature spring (2) . The seated pin
closes the lower seat and the seated pin opens the upper
seat. Actuation pressure is restored to the top of the check
piston (16) . This closes the nozzle check (19) and
injection ends. Actuation pressure is also felt under the
valve spool (6) . This restores the hydraulic balance on
the spool. The valve spring (5) slowly closes the spool.
This stops the flow of actuation oil to the intensifier
piston (8) .
As the spool raises, the check ball (7) for the intensifier
piston is no longer held closed. Oil in the cavity for the intensifier piston lifts the check off the seat and flows to
the drain (22) through a vent hole in the side of the injector. Return spring (9) pushes up plunger (10) and the
intensifier piston. This pushes all of the oil out of the cavity for the intensifier piston. The check valve (18) for
the fuel inlet is taken off of the valve seat as the plunger lifts up. This allows supply fuel to flow into the
plunger cavity. The fill cycle is complete when the plunger and the piston are at the top of the bore and the
plunger cavity is full of fuel.