A director plate retainer of a fluid injector includes an outer wall which is annular in shape and which extends from an outer wall first end to an outer wall second end and which is centered about an axis. The director plate retainer also includes a lateral wall which is annular in shape and which extends toward the axis from a radially outer extent, which is proximal to the outer wall, to a radially inner extent, which is distal from the outer wall. The director plate retainer also includes an inner wall which is annular in shape and which extends from an inner wall first end, which is proximal to the lateral wall, to an inner wall second end, which is distal from the lateral wall, the inner wall extending along the axis in a direction that is opposite from the outer wall.

A combined assembly for filtering and calibrating a fuel injector arranged in an internal combustion engine, the combined filtration and calibration assembly extending along a longitudinal axis and comprising a calibration sleeve provided with a longitudinal bore and defining a multitude of filtration holes. The combined filtration and calibration assembly has a calibrated opening in the bore.

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.

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.

A fuel injector with inlet and discharge ends includes a fuel tube through which fuel is admitted to a fuel passage extending to the discharge end. A valve element reciprocates against and away from a valve seat to prevent or allow fuel discharge. A calibration tube includes first and second ends and defines a portion of the fuel passage through which fuel must pass to the discharge end, the second end defining a spring seat engaging a spring and biasing the spring against the valve element. A fuel filter filters all fuel passing to the discharge end, and provides restriction of a first magnitude. The calibration tube includes a pressure pulsation damping orifice fluidly between the fuel filter and the discharge end through which fuel must pass to the discharge end, the pressure pulsation damping orifice provides restriction of a second magnitude which is greater than the first magnitude.

An RDU fluid injector includes a fluid inlet and a fluid outlet; a fluid path; an actuator unit including a pole piece, a movable armature and a coil; a valve assembly including a valve seat and a seal member connected to the armature and engageable with the valve seat; and a volume reduction member upstream of the actuator unit. The volume reduction member includes a throughbore partly defining the fluid path. The actuator unit, the valve assembly and the volume reduction member are disposed in one or more body portions of the injector, wherein each of the actuator unit, the valve assembly, the volume reduction member and the one or more body portions includes one or more components of the fluid injector. A ratio of a volume of the fluid path to a volume of the components of the fluid injector is between 0.08 and 0.30.

A fuel injector with inlet and discharge ends includes a fuel tube through which fuel is admitted to a fuel passage extending to the discharge end. A valve element reciprocates against and away from a valve seat to prevent or allow fuel discharge. A calibration tube includes first and second ends and defines a portion of the fuel passage through which fuel must pass to the discharge end, the second end defining a spring seat engaging a spring and biasing the spring against the valve element. A fuel filter filters all fuel passing to the discharge end, and provides restriction of a first magnitude. The calibration tube includes a pressure pulsation damping orifice fluidly between the fuel filter and the discharge end through which fuel must pass to the discharge end, the pressure pulsation damping orifice provides restriction of a second magnitude which is greater than the first magnitude.

A director plate retainer of a fluid injector includes an outer wall which is annular in shape and which extends from an outer wall first end to an outer wall second end and which is centered about an axis. The director plate retainer also includes a lateral wall which is annular in shape and which extends toward the axis from a radially outer extent, which is proximal to the outer wall, to a radially inner extent, which is distal from the outer wall. The director plate retainer also includes an inner wall which is annular in shape and which extends from an inner wall first end, which is proximal to the lateral wall, to an inner wall second end, which is distal from the lateral wall, the inner wall extending along the axis in a direction that is opposite from the outer wall.

A coil assembly includes an electric coiling included in an overmold, the coiling being suitable to drive the control valve of a fuel injector. The coil assembly is provided with a longitudinal bore suitable for receiving a spring and with an adjusting member for the setting of the spring which can be moved from outside the injector, the adjusting member forming a transfer of movement such that the movement of the adjusting member from outside the injector is transformed into a compression of the spring.

An RDU fluid injector includes a fluid inlet and a fluid outlet; a fluid path; an actuator unit including a pole piece, a movable armature and a coil; a valve assembly including a valve seat and a seal member connected to the armature and engageable with the valve seat; and a volume reduction member upstream of the actuator unit. The volume reduction member includes a throughbore partly defining the fluid path. The actuator unit, the valve assembly and the volume reduction member are disposed in one or more body portions of the injector, wherein each of the actuator unit, the valve assembly, the volume reduction member and the one or more body portions includes one or more components of the fluid injector. A ratio of a volume of the fluid path to a volume of the components of the fluid injector is between 0.08 and 0.30.