For a fuel injection device, a configuration to improve fuel sealability when a valve is closed is provided. Therefore, the fuel injection device includes: a valve body that opens and closes a fuel flow path; a movable iron core in which a fuel passage hole communicating an upstream side and a downstream side is formed, and that operates the valve body toward the upstream side; a biasing spring whose one end contacts the movable iron core, and that biases the movable iron core in a valve opening direction; and a regulating unit that regulates movement of the one end of the biasing spring, in which the shortest distance between the one end of the biasing spring and the fuel passage hole is larger than a radial travel distance of the one end until radial movement of the one end is regulated by the regulating unit.

A method to prevent generation of impact noise caused by an armature contacting a stopper due to a return spring and damage of the armature and a stopper without adding a part. Excitation of an electromagnetic coil 4 causes an armature 9 at a standby position to move in a plunger 7 direction so as to move the plunger 7 inserted in a pressurizing chamber 3 in a tip end direction against a return spring 8 to a level such that fuel is not injected from an injection nozzle 2. Fuel supplied from a fuel tank to the pressurizing chamber 3 through a fuel intake pipe 10 and inlet check valve 11 is pressurized and vapor included in the fuel inside the pressurizing chamber 3 is discharged to a fuel return pipeline 14 through a spill valve 12 and return passage 13. Excitation of the electromagnetic coil 4 is stopped, and then the electromagnetic coil 4 is re-excited prior to the armature 9 and plunger 7 reaching the standby position due to the return spring 8, such that the return speed of the armature 9 is reduced and an impact when the armature 9 contacts a stopper 15 is mitigated.

A method to prevent generation of impact noise caused by an armature contacting a stopper due to a return spring and damage of the armature and a stopper without adding a part. Excitation of an electromagnetic coil 4 causes an armature 9 at a standby position to move in a plunger 7 direction so as to move the plunger 7 inserted in a pressurizing chamber 3 in a tip end direction against a return spring 8 to a level such that fuel is not injected from an injection nozzle 2. Fuel supplied from a fuel tank to the pressurizing chamber 3 through a fuel intake pipe 10 and inlet check valve 11 is pressurized and vapor included in the fuel inside the pressurizing chamber 3 is discharged to a fuel return pipeline 14 through a spill valve 12 and return passage 13. Excitation of the electromagnetic coil 4 is stopped, and then the electromagnetic coil 4 is re-excited prior to the armature 9 and plunger 7 reaching the standby position due to the return spring 8, such that the return speed of the armature 9 is reduced and an impact when the armature 9 contacts a stopper 15 is mitigated.

An electromagnetic fuel injection valve includes a coupling between an armature and the valve member that allows limited relative movement of the valve member and armature in both the opening and closing directions of the valve member. An injector body includes a non-magnetic section to focus magnetic flux and attractive force through the armature and pole. A modular power group reduces the cost of assembly and includes a plastic encapsulated coil that is protected from environmental moisture and corrosion. A valve seat incorporates a valve seal which improves fuel flow past the valve member when the fuel injection valve is in the open position.

An electromagnetic fuel injection valve includes a coupling between an armature and the valve member that allows limited relative movement of the valve member and armature in both the opening and closing directions of the valve member. An injector body includes a non-magnetic section to focus magnetic flux and attractive force through the armature and pole. A modular power group reduces the cost of assembly and includes a plastic encapsulated coil that is protected from environmental moisture and corrosion. A valve seat incorporates a valve seal which improves fuel flow past the valve member when the fuel injection valve is in the open position.

A valve assembly for an injection valve is disclosed, including a valve body with a cavity, a valve needle axially moveable in the cavity, the valve needle being fixedly connected to a retaining element which extends in radial direction and is arranged in an axial region of the valve needle facing away from the fluid outlet portion, and an armature being able to slide on the valve needle and acting on the needle by way of the retaining element. A conical spring is arranged between the retaining element and a top side of the armature facing the retaining element, biasing the armature away from the retaining element.

A valve assembly for an injection valve is disclosed, including a valve body with a cavity, a valve needle axially moveable in the cavity, the valve needle being fixedly connected to a retaining element which extends in radial direction and is arranged in an axial region of the valve needle facing away from the fluid outlet portion, and an armature being able to slide on the valve needle and acting on the needle by way of the retaining element. A conical spring is arranged between the retaining element and a top side of the armature facing the retaining element, biasing the armature away from the retaining element.

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.

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.

The invention relates to a fuel injector for internal combustion engines for injecting fuel at high pressure, comprising a pressure chamber formed in an injector body, in which pressure chamber a nozzle needle is arranged in a longitudinally movable manner, which nozzle needle has a cone region tapered in a combustion chamber direction and a pin region having a constant diameter d23 at a combustion-chamber end of the nozzle needle. The injector body has a substantially conical nozzle needle seat, from which a first injection opening extends, and a blind hole, which adjoins the nozzle needle seat on the combustion chamber side. The blind hole has a cylindrical segment, which has the diameter d31, and a hole base, from which a second injection opening extends. The cone region of the nozzle needle interacts with the nozzle needle seat and thereby opens and closes the first injection opening and the second injection opening with respect to the pressure chamber. During a partial stroke of the nozzle needle, the first injection opening and the second injection opening are connected to each other by means of a throttle gap, which is formed in the blind hole between the pin region and the wall of the blind hole, and the throttle gap remains constant at least over the partial stroke of the nozzle needle.