Various embodiments include a method for operating a fuel injector having a hydraulic stop comprising: applying a first current profile to a solenoid drive to inject a predetermined injection quantity; ascertaining a first value of a parameter correlating to a velocity of the armature when reaching the hydraulic stop; determining whether the first value of the parameter is greater than a first threshold value; and if the first value of the parameter is greater than the first threshold value, applying a second current profile to the solenoid drive to carry out a second injection procedure. The second current profile in comparison with the first current profile exerts a lower magnetic force in the direction of the pole piece on the armature.

A fuel injection valve includes: a housing that includes an injection hole and a valve seat; a needle that includes a flange at a radially outer side of the needle and opens or closes the injection hole; a movable core that is installed on the valve seat side of the flange; a first spring that urges the needle toward the valve seat side; a second spring that urges the movable core toward an opposite side, which is opposite from the valve seat; and a limiting member that is installed on a radially outer side of the needle such that the limiting member enables movement of the movable core between the limiting member and the flange on the valve seat side of the flange. The limiting member includes an outside projection, which supports the second spring; and a tubular portion and an inside projection, which are contactable with the movable core.

A fuel injection valve includes a fixed core and a movable core. The fixed core includes a fixed-side high rigidity portion having high rigidity and a fixed-side low rigidity portion having rigidity lower than that of the fixed-side high rigidity portion. The movable core includes a movable-side high rigidity portion having high rigidity and a movable-side low rigidity portion having rigidity lower than that of the movable-side high rigidity portion. Current fed to a coil generates a magnetic attractive force to cause the movable core to move toward the fixed core together with a needle and to cause the movable-side high rigidity portion to abut on the fixed-side high rigidity portion.

The invention relates to a method for determining the injection rate of an injection valve (1) using a mathematical model which is based on measurement values comprising the stroke (x) of a piston (3) that delimits a measurement chamber (2) during the injection of a test fluid (4) into the measurement chamber (2). The injection rate is corrected on the basis of an additional measurement value. According to the invention, the pressure (p.sub.a) in an adapter volume (5), via which the injection valve (1) is connected to the measurement chamber (2), is used as an additional measurement value for correcting the injection rate. The invention further relates to a device for determining the injection rate of an injection valve.

A valve for metering a fluid, including an electromagnetic actuator and a valve needle which is actuatable by an armature of the actuator and used to actuate a valve closing body which cooperates with a valve seat surface to form a seal seat. The armature is movably guided at the valve needle in the process. A stop element connected to the valve needle limits a relative movement between the armature and the valve needle in connection with an actuation of the valve needle. At least one elastically deformable spacer element is provided between the armature and the stop element, which, during the limitation of the relative movement between the armature and the valve needle at the stop element, encloses an attenuation space provided between a front face of the armature and a stop element surface of the stop element facing the front face of the armature.

A valve for metering a fluid, for example, a fuel injection valve for an internal combustion engine, includes a valve-seat face, an electromagnetic actuator including an armature that includes a through-flow channel that opens with an outlet opening at an end face of the armature, a valve needle on which the armature is movably supported and that is operable using the armature, a valve-closing member that is actuatable by the valve needle and that cooperates with the valve-seat face to form a sealing seat, and a stop element that is mounted fixedly on the valve needle and that interacts with the at least one outlet opening of the at least one through-flow channel such that throttling takes place with respect to the least one through-flow channel when the armature is located with its end face at the stop element.

A valve includes an electromagnetic actuator, which has an armature in an armature space and guided on a valve needle operable by the actuator using the armature. A first and a second stop element that interact with a first and second end face, respectively, of the armature are situated on the valve needle. The armature has a spring receptacle, which is open towards the first end face of the armature, and into which a spring is inserted. The armature has at least one fluid channel, which, during operation, allows fluid to pass through between first and second regions of the armature space at the first and second end faces, respectively, of the armature. The fluid channel incorporates at least part of the spring receptacle. Sections of the fluid channel run radially outwards along a direction oriented from the first to the second end face and coaxial to a longitudinal axis.

A high pressure hydraulic system comprising: a hydraulic chamber containing pressurized fluid, a wall which encloses at least one part of the hydraulic chamber and has an integral diaphragm, a piezoelectric sensor isolated from the pressurized fluid contained in the hydraulic chamber by the diaphragm, and an elastic element arranged to apply an elastic force to the piezoelectric sensor, between the piezoelectric sensor and the diaphragm, so that a deformation of the diaphragm produced by a change in the pressure of the fluid contained in the hydraulic chamber causes a change in the elastic force that the elastic element applies to the piezoelectric sensor.

Valve assembly comprising: a valve body with an inlet and an outlet; a valve needle in the valve body preventing fluid flow through the outlet when closed and permitting the flow otherwise; a retaining element connected to the needle, extending radially and remote from the fluid outlet; and an electro-magnetic actuator to actuate the valve needle. The electro-magnetic actuator unit comprises an armature movable relative to the valve body. The armature defines a central axial opening through which the valve needle extends and slides on the valve needle. The retaining element limits the axial displacement of the armature. The armature comprises at least one axial slot arranged adjacent to and connected with the central axial opening, extending through the armature in the axial direction. The retaining element projects beyond the central axial opening and the axial slot projects beyond the retaining element in the radial outward direction.

A fluid metering valve includes a valve needle that is actuatable by an electromagnetic actuator that includes an armature guided on and along a longitudinal axis of the valve needle with a movement limited by a stop surface on the valve needle. A projection of an edge of the stop surface extends into a projection plane, perpendicular to the longitudinal axis and at which the armature and stop surface are in contact temporarily during operation, through an opening of a conduit of the armature, dividing the opening into an inner surface on one side of the projection and an outer surface on the other side of the projection. A fluid exchange between inside and outside of an area between the stop surface and armature is via a path through the inner surface, conduit, and outer surface when the armature is in contact with the stop surface at the projection plane.