Abstract: A high pressure fuel pump includes an inlet metering valve arranged to control a quantity of fuel delivered to the pumping chamber during retracting motion of the pumping plunger. The inlet metering valve includes a metering valve member movable between a closed position and an open position, movement of the metering valve member from the closed position to the open position defining a variable flow area that increases as the metering valve member moves from the closed position toward the open position. An actuator piston in an actuator bore is exposed to pressure in the common rail. The actuator piston is biased toward a first position corresponding to low pressure in the common rail and movable toward a second position corresponding to maximum pressure in the common rail. The actuator piston includes a valve stop that determines a metering position of the metering valve member.

Abstract: A high pressure fuel pump includes an inlet metering valve arranged to control a quantity of fuel delivered to the pumping chamber during retracting motion of the pumping plunger. The inlet metering valve includes a metering valve member movable between a closed position and an open position, movement of the metering valve member from the closed position to the open position defining a variable flow area that increases as the metering valve member moves from the closed position toward the open position. An actuator piston in an actuator bore is exposed to pressure in the common rail. The actuator piston is biased toward a first position corresponding to low pressure in the common rail and movable toward a second position corresponding to maximum pressure in the common rail. The actuator piston includes a valve stop that determines a metering position of the metering valve member.

Abstract: The disclosed inlet check valve is used in a high pressure fuel pump and is comprised of a valve member integrally connected to a valve stem which is coupled to an inlet valve armature. The valve member has a stroke along an axis between an open position and a closed position. An inlet valve solenoid generates a magnetic field in an inlet valve pole to attract the inlet valve armature and move the valve member from the open position to the closed position. In the open position, the valve member contacts an inlet valve stop and a gap greater than the stroke of the valve member is defined along the axis between the inlet valve armature and the inlet valve pole. In the closed position, an inlet valve seat mates with the valve member and an armature gap remains between the inlet valve armature and the inlet valve pole.

Abstract: The disclosed integrated outlet check valve and pressure relief valve are used in a high pressure fuel pump including a pumping chamber and an outlet fitting defining an outlet passage to a common rail. The pressure relief valve comprises a movable pressure relief valve shuttle including a pressure relief valve surface configured to mate with a pressure relief valve seat in a closed position. The pressure relief valve shuttle moves from the closed position to an open position when pressure in the common rail exerts a force greater than the bias of a pressure relief valve spring. The pressure relief valve shuttle also includes an outlet check valve seat configured to mate with an outlet check valve ball in a closed position. The outlet valve ball moves from the closed position to an open position when pressure in the outlet passage is less than pressure in the pumping chamber.

Abstract: The disclosed inlet check valve is used in a high pressure fuel pump and is comprised of a valve member integrally connected to a valve stem which is coupled to an inlet valve armature. The valve member has a stroke along an axis between an open position and a closed position. An inlet valve solenoid generates a magnetic field in an inlet valve pole to attract the inlet valve armature and move the valve member from the open position to the closed position. In the open position, the valve member contacts an inlet valve stop and a gap greater than the stroke of the valve member is defined along the axis between the inlet valve armature and the inlet valve pole. In the closed position, an inlet valve seat mates with the valve member and an armature gap remains between the inlet valve armature and the inlet valve pole.

Abstract: A fuel pump including a low pressure infeed leading to a pumping chamber, a pumping plunger for pressurizing fuel in the pumping chamber, an outlet valve for delivering pressurized fuel from the pumping chamber to a high pressure outlet line during pumping, and an overpressure relief valve connected between the high pressure outlet line and the pumping chamber. A ball type relief valve element is spring biased to close against the relief valve seat. The spring is in a spring chamber that is fluidly isolated from the pumping chamber while the valve element is closed, preferably in direct hydraulic communication with the low pressure infeed, thereby reducing dead volume during normal pumping. The spring can act on the valve element through a piston, and in an alternative embodiment, the piston can provide a spill path from the pumping chamber to the low pressure infeed.

Abstract: A fuel pump including a low pressure infeed leading to a pumping chamber, a pumping plunger for pressurizing fuel in the pumping chamber, an outlet valve for delivering pressurized fuel from the pumping chamber to a high pressure outlet line during pumping, and an overpressure relief valve connected between the high pressure outlet line and the pumping chamber. A ball type relief valve element is spring biased to close against the relief valve seat. The spring is in a spring chamber that is fluidly isolated from the pumping chamber while the valve element is closed, preferably in direct hydraulic communication with the low pressure infeed, thereby reducing dead volume during normal pumping. The spring can act on the valve element through a piston, and in an alternative embodiment, the piston can provide a spill path from the pumping chamber to the low pressure infeed.