Patent ID: 6874474

Claim:
An injection pump for a common rail fuel injection system of an internal combustion engine, the pump comprising a pump cylinder ( 5 ), disposed in a housing ( 1 ), a piston ( 3 ) oscillating in the pump cylinder ( 5 ), wherein the pressure of the fuel aspirated from a fuel inlet chamber ( 29 ) into the pump cylinder ( 5 ) is increased by the piston ( 3 ), and a quantity control valve ( 17 ), wherein the quantity control valve ( 17 ) has a directly triggered control piston ( 15 ) integrated with the housing ( 1 ), the quantity control valve ( 17 ) controlling the pumping flow of the piston ( 3 ) into a fuel inlet ( 27 ) or into a high-pressure bore ( 23 ) communicating with a common rail, and the piston ( 3 ) oscillating at a frequency greater than or equal to half the crankshaft rpm of the engine during operation, further comprising a sealing seat between the housing ( 1 ) and the control piston ( 15 ) sealing off the communication between the fuel inlet ( 27 ) and the pump cylinder ( 5 ), the diameter of the sealing seat being less than the diameter of a receiving bore ( 39 ) in the housing ( 1 ) for the control piston ( 15 ).