The invention relates to a fuel injector for injecting two liquid and/or gaseous fuels with an injector housing (1), comprising a nozzle body (2) and a valve body (3). A first nozzle needle (7), arranged such that it can move in a stroke-like manner, is arranged in said injector housing (1) for opening and closing an injection cross-section (27). The first nozzle needle (7) is thereby designed as a hollow needle in which a second nozzle needle (8), arranged such that it can move in a stroke-like manner, is arranged. Same cooperates with an inner nozzle seat (25) formed in the first nozzle needle (7) to open and close at least one injection opening (35). The first nozzle needle (7) and the second nozzle needle (8) border an injection chamber (20) that can be filled with fuel via a supply throttle (36). In addition, in an upper switch position, the second nozzle needle (8) is in contact with a seal seat (38) and thereby separates a connection between the injection chamber (20) and the supply throttle (36).

An object of the present invention is to provide a fuel injection device in which variations in an injection flow rate for each injection is suppressed and an injection amount is stabilized.

The fuel injection device according to the present invention includes: a valve element that is seated on or unseated from a valve seat; a plurality of guide parts (302a, 302b, 302c) that slidably guide the valve element; and flow paths (306a, 306b, 306c) sandwiched between the guide parts in a circumferential direction. In the fuel injection device, one guide part (302a) among the plurality of guide parts is formed to have a longer circumferential length than that of other guide parts (302b, 302c).

A spark-ignition direct fuel injection valve includes, at least, a seat member provided with a fuel injection hole and a valve seat and a valve body which controls fuel injection from the injection hole by contacting and separating from the valve seat. In the spark-ignition direct fuel injection valve: the injection hole has an injection hole inlet which is open inwardly of the seat member and an injection hole outlet which is open outwardly of the seat member; an opening edge of the injection hole inlet has a first round-chamfered portion formed on an upstream side with respect to a fuel flow toward the injection hole inlet; and an extending length (L) of the injection hole does not exceed three times a hole diameter (D) of the injection hole.

A drive unit of a fuel injection device includes a driver circuit. The driver circuit opens and closes a valve element of the fuel injection device by supplying a drive current to the fuel injection device. The driver circuit supplies the drive current to open the valve element and sets the drive current to zero in an intermediate lift area. The intermediate lift area is an area is which a lift amount of the valve element is smaller than a maximum target lift amount.

An electromagnetic fuel valve has a valve chamber, a valve element and a valve seat assigned to the valve element. The valve chamber is delimited by an electromagnetic drive which moves the valve element relative to the valve seat. The drive includes a receiving housing for a coil carrier with an electrical coil. A magnet core is inserted into the coil carrier and has an end section facing the valve element. At an open sealing end facing toward the valve chamber, a sealing element is arranged between the end section of the magnet core and the receiving housing. To achieve good sealing, that end section of the magnet core situated in the sealing element expands the sealing element and compresses the material thereof radially against the edge of the sealing end of the receiving housing to seal the valve chamber to the interior space of the receiving housing.

The housing includes a first cylinder part having a first end connected to a nozzle, a second cylinder part having a first end connected to a second end of the first cylinder part and forming a magnetic throttle part in at least a part of the second cylinder part in an axial direction, a third cylinder part having a first end connected to a second end of the second cylinder part, and a fuel passage formed inside the first cylinder part, the second cylinder part, and the third cylinder part so as to communicate with injection holes and guide the fuel to the injection holes. A yoke has a cylindrical shape, of which the first end side is connected to the first cylinder part and the second end side is connected to the third cylinder part, and is provided on a radially outer side of the housing such that an axial force is generated in the first cylinder part and the third cylinder part in a direction in which the first cylinder part and the third cylinder part approach each other.

A fuel injection control device is adapted for a fuel injection system including an injector and a high-pressure pump that raises pressure of fuel and supplies the fuel to the injector. The fuel injection control device includes a selecting unit for selecting by which one of full lift injection and partial injection to inject fuel, and a pump control unit for controlling operation of the high-pressure pump such that a pressure of fuel supplied to the injector coincides with a target pressure. The selecting unit selects the partial injection when a required injection quantity of fuel is equal to or smaller than a partial maximum injection quantity. A fuel injection system includes the fuel injection control device, the injector, and the high-pressure pump.

A spray disc arrangement for a fluid injector includes a first disc having a dimple with an orifice defined through the dimple. A second disc includes a dimple and a plurality of orifices defined through the dimple. The first disc dimple is received in the second disc dimple. The second disc includes a plurality of channels defined along a concave surface of the dimple, with the plurality of orifices located in the channels. The first disc and the second disc are coupled together such that a convex surface of the dimple of the first disc contacts a concave surface of the dimple of the second disc. The first disc is disposed along a downstream side of a valve seat of the fluid injector.

A gas injector for injecting a gaseous fuel. The gas injector includes a solenoid actuator including an armature, an internal pole, and a coil; a closure element which opens and closes a gas path on a valve seat, the armature being connected to the closure element; a closed lubricant chamber filled with a lubricant and in which the armature is arranged, the lubricant ensuring the armature is lubricated; a flexible sealing element sealing the lubricant chamber in relation to the gas path, and a braking device which is arranged in the lubricant chamber and is configured to brake the closure element during a process of restoring the gas injector from the open into the closed state. The braking device has a brake pin, a damping chamber that is filled with lubricant and is in fluid communication with the lubricant chamber, and a resilient brake element.

A method of controlling a fuel injection device that can control a small amount of injection is provided. A fuel injection device for use in an internal combustion engine, includes: a valve body that can open and close a fuel passage, a needle that transfers a force with the valve body, and executes valve opening/closing operation, and an electromagnet that includes a coil and a magnetic core provided as a driver for driving the needle, and a cylindrical nozzle holder disposed on an outer periphery of the magnetic core and the needle, in which a current is supplied to the coil to exert a magnetic attractive force between the magnetic core and the needle to open the valve body.