An assembly at least comprising a fuel injector for dual fuel operation of an internal combustion engine. The assembly includes a nozzle holder defining a fuel circuit and provided with a nose adapted in use to be in connection with a combustion space of an internal combustion engine, and first and second nozzles in communication with the fuel circuit in the nozzle holder for directly injecting liquid fuel into the combustion space of the internal combustion engine for ignition of a combustible mixture present in the combustion space. The first and second nozzles adjacent to the nose of the nozzle holder are interconnected by a cooling channel. At each actuation of a fuel pump upstream of the first and second nozzles, substantially a full volume of fuel pumped during actuation of the fuel pump is allowed to flow through the cooling channel and via the first and second nozzles.

Methods and systems are provided for continuously estimating a direct injector tip temperature based on heat transfer to the injector from the cylinder due to combustion conditions, and heat transfer to the injector due to flow of cool fuel from the fuel rail. Variations in the injector tip temperature from a steady-state temperature are monitored when the direct injector is deactivated. Upon reactivation, a fuel pulse width commanded to the direct injector is updated to account for a temperature-induced change in fuel density, thereby reducing the occurrence of air-fuel ratio errors.

A fuel passage leads a fuel from a pressure-accumulation vessel to a nozzle hole of a fuel injection valve. A fuel pressure sensor detects a fuel pressure in a fuel passage. An estimation device is applicable to a combustion system, which includes these components, and includes a mixing acquisition unit and an injection amount estimation unit. The mixing acquisition unit acquires the mixing ratio of various components contained in the fuel used for combustion in the internal combustion engine. The injection amount estimation unit estimates an injection amount of the fuel from the nozzle hole according to a change mode of the fuel pressure, which is detected with the fuel pressure sensor and associated with injection of the fuel from a nozzle hole, and the mixing ratio acquired with the mixing acquisition unit.

A fuel injector for an internal combustion engine includes an injector body in which there are positioned an actuator, a control valve, and a needle guide. The actuator actuates the control valve, the control valve controlling an injection needle sliding the needle guide between an open position in which injection is permitted and a closed position in which the injection of fuel is prevented. The injector additionally includes a first electrical connection extending from the needle guide to a metal that are internal to the injector, and a metal extension extending from the metal ring to a connector pin accessible from the outside of the injector, so that an electrical signal indicative of the position of the needle can be transmitted from the needle guide for the needle to the connector pin.

An immersed axial fuel stage (AFS) injector includes an injector body configured to be positioned in a hot gas path within a combustion liner. The injector body includes an outer wall defining a hollow interior and having film cooling holes extending from the hollow interior to an outside of the outer wall, and an inner wall spaced from an inside of the outer wall along at least part of a length of the outer wall, the inner wall defining an air plenum therein. Impingement cooling holes in fluid communication with the air plenum extend through the inner wall along at least a portion of the inner wall. A fuel passage extends at least partially along the hollow interior of the outer wall, and fuel nozzles in fluid communication with the fuel passage extend through to the outside of the outer wall.

Methods and systems are provided for continuously estimating a direct injector tip temperature based on heat transfer to the injector from the cylinder due to combustion conditions, and heat transfer to the injector due to flow of cool fuel from the fuel rail. Variations in the injector tip temperature from a steady-state temperature are monitored when the direct injector is deactivated. Upon reactivation, a fuel pulse width commanded to the direct injector is updated to account for a temperature-induced change in fuel density, thereby reducing the occurrence of air-fuel ratio errors.

In the interior of a resin mold portion that constitutes a fuel injection valve, an amplifying member to which a power source terminal and a signal terminal are connected, is provided. A signal transmitting unit, which outputs a detection signal from a sensor, is connected electrically to a substrate of the amplifying member. Further, the amplifying member is molded integrally when the resin mold portion is formed. In addition, a pressure inside a combustion chamber of an internal combustion engine, which is detected by the sensor, is output through the signal transmitting unit to the amplifying member, is amplified by the amplifying member, and is output externally from the signal terminal.

Temperature measuring device for measuring the temperature of a member, the member including a component controlled by a control signal, active at most during at least one limited activity interval, and transmitted to the component via two wires, a temperature probe connected to the two wires, in parallel with the component, and a diode, connected between a terminal of the component and a terminal of the probe connected to the same wire, in order to allow the passage of a current in the component only in a first direction, the temperature measurement being performed by a current flowing in a second direction, opposite to the first direction, outside of the activity interval.

A method for regulating a common rail injector, the method including acquiring a signal of a sensor, which signal is proportional to a pressure in a valve space of the common rail injector; evaluating a change in the signal over time in order to detect at least one operating event of the common rail injector; and modifying at least one operating variable of the common rail injector as a function of the at least one operating event, the at least one operating variable being selected from an opening duration, a closing duration, an opening point in time, and a closing point in time of a switching valve of the common rail injector, and from an opening duration, an opening point in time, and a closing point in time of a needle valve of the common rail injector.

A method according to the invention for checking the plausibility of the function of a pressure sensor in an injection system of an internal combustion engine includes acquiring a calibrated actuation profile, by which peak current values for opening at least one electrically actuatable injection valve are assigned to existing internal pressures. An existing internal pressure is measured in the form of an actual sensor pressure value by the pressure sensor. The method includes obtaining the electrical peak current value corresponding to the measured sensor pressure value from a calibrated actuation profile, such that the corresponding electrical peak current value acquired in this way is applied to the injection valve. Subsequently, an opening state of the injection valve is monitored in reaction to the applied electrical peak current value, and a functional state of the pressure sensor is assigned as a function of the opening state of the injection valve.