Raise

Raise

Filling cycle cross section (1) Solenoid valve (2) Armature spring (3) Armature (4) Seat pin (5) Spool valve spring (6) Spool valve (7) Intensifier piston check ball (8) Intensification Piston (9) Return spring (10) Plunger (16) Check valve piston (18) Reverse flow check valve (19) Nozzle check valve (22) Oil discharge port

When the solenoid valve (1) is de-energized, the filling cycle begins. The armature spring (2) pushes the armature (3) and the seat pin (4) downward. The seat pin closes the lower base and opens the upper base. The drive pressure at the top of the check valve piston (16) is restored. As a result, the nozzle check valve (19) is closed and the fuel injection ends. The underside of the spool valve (6) is also affected by the driving pressure. This restores the hydraulic balance on the spool valve. The spool valve spring (5) slowly closes the spool valve, thereby blocking the flow of drive oil to the intensifier piston (8).

When the spool valve is raised, the one-way ball (7) of the intensifier piston no longer remains closed. The oil in the piston chamber of the intensifier lifts the check valve away from the valve seat and flows to the oil discharge port (22) through the discharge hole on the side of the fuel injector. The return spring (9) pushes up the plunger (10) and the intensifier piston, thereby expelling all the oil in the intensifier piston chamber. When the plunger is raised, the check valve (18) of the fuel inlet is released from the valve seat. This allows the fuel supply to flow into the plunger chamber. When the plunger and piston are at the top of the hole and the plunger chamber is full of fuel, the filling cycle is complete.