A fuel injection system includes a first high pressure fuel source, a return channel connected to a second low pressure fuel source, a residual pressure regulator having an inlet and an outlet connected to the return channel, and a fuel injector having a control valve arrangement comprising an inlet, an outlet and a return port, a fuel injection nozzle having an outlet chamber, an injection outlet, and a needle member in the outlet chamber. The needle member is biased to a closed position to block fluid communication between the outlet chamber and the injection outlet, and to open fluid communication by a pressure in the outlet chamber. The residual pressure regulator is connected to a spill valve to regulate pressure to a residual pressure higher than the pressure in the return channel and lower than the pressure of the first fuel source.

Device for controlling an injector, including a passage space which can be closed off on one of its two sides by an armature element in order to thereby optionally separate a fluid high-pressure region from a fluid low-pressure region of the injector, a control space for applying a variable pressure to an injector component, preferably an injector needle, a valve which is arranged between another of the two sides of the passage space and the control space, a first connection which connects the high-pressure region of the injector to the passage space, and a second connection which connects the passage space to the control space, wherein the valve is configured to establish a direct connection between the high-pressure region and the control space if the pressure level in the passage space is equal to or higher than a predetermined value.

Methods and systems are provided for a solenoid actuator. In one example, a method may include adjusting a switching frequency during an activation cycle of the solenoid actuator to a lower switching frequency relative to other phases of the activation cycle.

Operating an engine includes injecting a first charge of liquid fuel using a first set of nozzle outlets in a fuel injector, and injecting a second charge of liquid fuel using a second set of nozzle outlets in a fuel injector. The first charge is autoignited in a first engine cycle, and the second charge is autoignited in a second engine cycle, and may be used to pilot ignite a charge of gaseous fuel. Operating the engine further includes limiting errors in targeting of the second charge of liquid fuel caused by transitioning the engine from a first combination to a second combination of speed, load, and boost, by varying an injection pressure of the liquid fuel from the first engine cycle to the second engine cycle.

A fuel injector device for injecting fuel into a combustion chamber of an internal combustion engine is provided. Included in the fuel injector is a body having a chamber and a pilot valve assembly including a seat retainer configured to be detachably insertable into the chamber of the body. A pilot valve seat is disposed in the seat retainer and substantially enclosed by the seat retainer. A stator assembly is disposed in the seat retainer and at least partially enclosed by the seat retainer. The pilot valve seat and the stator assembly in the pilot valve assembly are replaceable as a single unit of the pilot valve assembly for the fuel injector.

A needle stroke switch and a fuel injector having such a switch, the needle stroke switch including a seat plate having a plate-like main body and a passage connecting the two planar sides of the plate-like main body, an anchor element which can be lifted off from the passage in the seat plate, and a control valve which is arranged on the side of the seat plate opposite the anchor element and is designed to interact with a nozzle needle. The seat plate is electrically isolated from a surrounding injector housing and an electrical connection to the injector housing is possible only via the nozzle needle which interacts with the seat plate. Furthermore, the needle stroke switch is characterised in that at least one ceramic and/or plastic part is provided which contacts the seat plate in order to isolate the seat plate from the surrounding injector housing.

A flow control system for a fuel injector of an internal combustion engine includes: an inlet channel, an outlet channel, a return channel for returning pressurized fuel to a low-pressure system having a lower pressure than the inlet channel, a fuel outlet chamber, a moveable nozzle control member in the fuel outlet chamber for selectively allowing the pressurized fuel to flow into the outlet channel, a biasing member biasing the nozzle control member towards a closed position, a moveable member defining, with the nozzle control member, a fuel control chamber configured to bias the nozzle control member towards its closed position, a moveable valve member for selectively opening and closing a flow passage and a fuel connection between the inlet channel and the fuel control chamber for pressurizing the fuel control chamber.

In a control system that includes a pressure accumulating portion that supplies CNG to a fuel injection valve and a regulator that adjusts a pressure in the pressure accumulating portion to a set pressure and of which a valve element opens when CNG is supplied to the pressure accumulating portion and closes when supply of CNG to the pressure accumulating portion is shut off, a control parameter relating to a combustion state in an internal combustion engine is controlled on the basis of a length of a period during which an opening degree of the valve element reduces from a first predetermined opening degree to a second predetermined opening degree when the pressure in the pressure accumulating portion is adjusted to the set pressure by the regulator.

In a control system that includes a pressure accumulating portion that supplies CNG to a fuel injection valve and a regulator that adjusts a pressure in the pressure accumulating portion to a set pressure and of which a valve element opens when CNG is supplied to the pressure accumulating portion and closes when supply of CNG to the pressure accumulating portion is shut off, a control parameter relating to a combustion state in an internal combustion engine is controlled on the basis of a length of a period during which an opening degree of the valve element reduces from a first predetermined opening degree to a second predetermined opening degree when the pressure in the pressure accumulating portion is adjusted to the set pressure by the regulator.

A fuel injection device injecting a fuel from an injection hole to a combustion chamber of an internal combustion engine includes a valve body including a fuel passage through which the fuel flows to the injection hole and a seat portion facing the fuel passage, a valve member moving in the valve body in an axial direction of the valve body and opening and closing the injection hole by being removed from and seated on the seat portion, a dividing member defining a pressure control chamber placed at a position opposite to the injection hole with respect to the valve member, and an outer peripheral member surrounding an exterior of an outer periphery of the dividing member. The pressure control chamber controls a movement of the valve member by a pressure of the fuel that is introduced. The outer peripheral member and the valve body constitute the fuel passage.