Patent ID: 8272856

Claim:
A high-pressure pump, in particular for a fuel injection apparatus of an internal combustion engine, comprising: at least one pump element; a pump piston of the pump element that is driven to execute a stroke motion; a pump working chamber of the pump element being delimited by the pump piston; a fuel supply from which fuel is drawn into the pump working chamber during a suction stroke of the pump piston; an inlet valve comprising a valve housing having interior side walls through which the fuel is drawn from the fuel supply into the pump working chamber; a high-pressure region into which the fuel is displaced from the pump working chamber during a delivery stroke of the pump piston; an outlet valve comprising a valve housing having interior side walls through which the fuel is displaced from the pump working chamber into the high-pressure region; said inlet valve and/or said outlet valve each having a valve member that defines a sealing surface which is at least approximately as a ball having a diameter; said inlet valve and/or/outlet valve each including a valve seat in said housing that cooperates with the sealing surface of the valve member thereby blocking flow therethrough; said valve member disposed in said housing to have an initial movement and a subsequent movement; a first flow cross section formed between the sealing surface of the valve member and the valve seat when the sealing surface of the valve member is lifted away from the valve seat in an open state during said initial movement; a second flow cross section downstream of the first flow cross section, formed between the diameter of said sealing surface of the valve member and a separate insert piece mounted in the valve housing during said subsequent movement between which defines said second flow cross section; said separate insert piece is disposed downstream of said valve seat a distance such that said second flow cross section is reached only during said subsequent movement of said valve member; a third flow cross section formed between the sealing surface of the valve member and the interior side walls of the valve housing only during said initial movement in the flow direction between the first flow cross section and the second flow cross section, wherein the third flow cross section is larger than the first flow cross section and the second flow cross section; and wherein the second flow cross section is smaller than the first flow cross section when the diameter of the valve member aligns with said second flow cross section.