A fuel system for an internal combustion engine includes an actuation train having a cam follower, a pushrod, a rocker arm, and a camshaft having a cam lobe rotatable in contact with the cam follower according to an ascending ramp phasing, a peak phasing, and a descending ramp phasing. The fuel system further includes a fuel injector including an electrically actuated spill valve. A fueling control unit is in communication with the spill valve and structured to close the spill valve during the ascending ramp phasing, such that a plunger cavity pressure is increased to oppose a plunger-advancement inertia of the actuation train. Related methodology and control logic is also disclosed.

An electromagnetic actuation system includes an actuator having an electrical coil, a magnetic core, and an armature. The system further includes a controllable bi-directional drive circuit for selectively driving current through the electrical coil in either of two directions. The control module provides an actuator command to the drive circuit effective to drive current through the electrical coil in a first direction to actuate the armature and in a second direction subsequent to armature actuation to oppose residual flux within the actuator. The control module includes a residual flux feedback control module configured to adapt the actuator command to converge residual flux within the actuator to a preferred flux level.

A fuel injection valve includes: a holder which accommodates a valve body, has a surface magnetically facing the outer periphery of an armature, and is joined to a core; a housing which is press-fitted onto the outer periphery of the holder and accommodates a coil; and a cap which covers the fuel upstream side of the coil in a lid shape and is press-fitted onto the outer periphery of the core. The lower surface of the cap is brought into contact with the upper end surface of the housing in a radially slidable state and then an outer peripheral portion of a contact surface between the cap and the housing is joined by laser welding.

A method for determining an effective injection time of a valve having a coil drive includes determining an opening time of the valve, determining a closing time of the valve, and determining the effective injection time of the electric actuation of the valve for an injection operation based on the defined opening time and the defined closing time.

A fuel system includes a fuel injector, and a fueling control unit electrically connected to a solenoid actuator in the fuel injector. The fueling control unit is structured to energize and deenergize the solenoid actuator to lift and return an armature coupled with an injection control valve. The fueling control unit also reenergizes the solenoid actuator with an armature retarding current while the armature is in flight to stabilize closing of the injection control valve. The armature retarding current can be used to electronically trim the fuel injector to limit an error in a quantity of injected fuel.

A valve for injecting fuel, including a valve positioning element, an armature connected to the valve positioning element, a stop that limits a movement of the armature, and a damping element provided between the armature and the stop, the damping element being applied as a damping layer on at least one part of the armature and/or on at least one part of the stop.

A fuel injection valve is provided that can reduce variations in stroke length by reducing distortion during welding, and consequently can reduce variations in flow rate of injected fuel. The fuel injection valve has a nozzle; a fixed valve that is press-fit into a tip of the nozzle and has a fuel injection port from which the fuel is injected; and a movable element that forms a fuel seal section by abutting against the fixed valve, and opens and closes the fuel injection port. The fixed valve and the nozzle are fixed in place by welding at a position with no space due to press-fitting. A groove that serves as an empty space is provided in a continuation of a welded section that is formed in the fixed valve and the nozzle by the welding.

A fuel injector includes a fuel valve with a valve seat and a movable valve needle, a calibration spring and an electromagnetic actuator with a solenoid and a movable armature. The calibration spring exerts a pressing force on the valve needle for pressing the valve needle in a closing direction towards the valve seat. When the solenoid is electrically energized, the electromagnetic actuator is operable to transfer a lifting force to the valve needle by engagement with the armature for lifting the valve needle from the valve seat to a fully open position against the pressing force of the calibration spring. The calibration spring and the electromagnetic actuator are configured such that the lifting force equals the pressing force in the fully open position.

In an electromagnetic fuel injection valve for in-cylinder injection, a fuel injection hole is an elongated hole having a major axis and a minor axis, the major axis being curved into an arc shape having a radius that is smaller than a radius of a pitch circle of an inlet of the fuel injection hole. Accordingly, the electromagnetic fuel injection valve can ensure a required flow rate even when a penetrating power is decreased.

In a fuel injection valve, when a regulating unit provided in a needle abuts against a movable core, a gap is defined between a flange portion end face of a flange portion and a movable core first end face of the movable core. With the above configuration, when a coil develops a magnetic field, because the movable core abuts against a flange portion while accelerating in a valve-opening direction, a relatively large force is exerted on the needle in the valve-opening direction. The needle is further moved in the valve-opening direction by an urging force of a second spring after the movable core has abutted against the fixed core. With the above configuration, a lift quantity of the needle is longer than a distance by which the movable core moves until the movable core abuts against a fixed core abutting portion since the movable core abuts against the flange portion. As a result, the lift quantity of the needle can be increased without any increase in the electric power to be supplied to the coil.