A fuel injector is configured such that a non-magnetic member constituting a magnetic circuit is deformed by an axial force generated when the non-magnetic member is combined with a cover and a housing, thereby providing airtight contact. The fuel injector is a device that injects fuel into an engine by raising a needle. A magnetic field generated from a coil forms a magnetic circuit when the coil is magnetized, and the magnetic circuit raises the needle. The fuel injector includes a block ring disposed inside the coil, a cover disposed at an upper end of the block ring, and a housing disposed at a lower end of the block ring. The block ring is made of a non-magnetic material and configured to extend the magnetic circuit. When the cover and the housing are combined by being screwed together, the upper end and the lower end of the block ring are deformed to provide airtight contact with respect to the cover and the housing, respectively.

An upper housing is provided between a fixed core and a housing opposite to a nozzle hole with respect to a coil. The upper housing is configured to form a magnetic circuit with the fixed core and the housing. The upper housing has a first tapered surface formed on an outer peripheral wall and a first cylindrical surface formed on an inner peripheral wall. The housing has a second tapered surface that radially faces the first tapered surface. The fixed core has a second cylindrical surface that radially faces the first cylindrical surface.

In general, the subject matter described in this disclosure can be embodied in a fuel injector that includes an upper housing portion that defines an inlet passage adapted to receive fuel, and a lower housing portion that is attached to the upper housing portion and that defines an injector outlet adapted to dispense fuel. The fuel injector includes an electromagnetic coil assembly that is user removable while the upper housing portion remains attached to the lower housing portion. The fuel injector includes a movable pintle that is biased to a closed position that is adapted to prevent fuel from flowing through the injector outlet, and movable, responsive to magnetic force produced by energizing the electromagnetic coil assembly, to an open position that is adapted to permit fuel to flow through the injector outlet.

An injector, for injecting a fuel fluid into an intake manifold or into a combustion chamber of a cylinder of an internal combustion engine, includes an electromagnetic actuator that includes a magnetic circuit. The magnetic circuit includes a solenoid, an internal pole, and a magnet armature that cooperates with the solenoid and the internal pole, and is configured to generate a controlled force action between the internal pole and the magnet armature when the electromagnetic actuator is activated with the aid of an activating current and/or an activating voltage. The injector includes a gap in the area between the internal pole and the magnet armature, and includes a valve sleeve that has either paramagnetic material properties in and outside the area of the gap or paramagnetic material properties in the area of the gap and ferromagnetic material properties outside of this area.

A solenoid valve includes an inner stator and an outer stator that are part of a magnetic circuit. An armature is attracted toward the inner stator when a coil is energized. A spring biases the armature in a direction away from the inner stator. A rod is integrally formed with the armature and integrally reciprocates with the armature. A guide guides reciprocation of the rod. A valve operates by following the rod to open and close a fuel/liquid passage. The spring and sliding portions between the rod and the guide are arranged within a recess portion formed in the inner stator and arranged in parallel to each other while overlapping in the axial direction.

A system for controlling actuation of an electromagnetic actuator includes an actuator having an electrical coil, a magnetic core, and an armature. A controllable drive circuit is responsive to an electric power flow signal for driving current through the electrical coil to actuate the armature. A control module includes an armature motion observer configured to determine an armature motion parameter in the actuator based upon a magnetic flux within the actuator and a predetermined mechanical equation of motion corresponding to the actuator and adapt the electric power flow signal based on the armature motion parameter.

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 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.

In order to reduce the friction of a dry-running solenoid valve (1) with a valve housing (2), in which an electric coil (3) and a magnet armature (5) are arranged, and with a valve element (8) which can be actuated by the magnet armature (5) in an axial actuating direction for opening and closing the solenoid valve (1), in which the coil (3) generates a magnetic flux which, when the solenoid valve (1) is actuated, flows via a magnetically conductive valve housing outer wall (2c) of the valve housing (2) to the magnet armature (5), it is provided according to the invention that a magnetically conductive flux element (12) be provided in the valve housing (2) and introduce at least 80%, preferably at least 90%, and particularly preferably 100%, of the magnetic flux flowing over the valve housing outer wall (2c) into an armature end face (5B), facing the coil (3), of the magnet armature (5).

In order to provide a solenoid valve (1) with a valve housing (2), in which an electric coil (3) and a magnet armature (5) are arranged, and with a valve element (8) which can be actuated by the magnet armature (5) in an axial actuation direction for opening and closing the solenoid valve (1), wherein a valve lift of the valve element (8) can be limited in a simple manner, it is provided according to the invention that the coil (3) be arranged on a coil carrier (4), wherein an end section (4a), axially facing the magnet armature (5), of the coil carrier (4) is designed as an end stop for the magnet armature (5) in order to limit an axial movement of the magnet armature (5), and that the coil carrier (4) be formed from a plastic, wherein the coil (3) is at least partially integrated into the coil carrier (4).