An injection hole body has an injection hole to inject fuel for causing combustion in an internal combustion engine. A valve body is unseated from and seated on a seating surface of the injection hole body. The injection hole body and the valve body form a fuel passage therebetween to communicate with an inflow port of the injection hole. The fuel passage is opened and closed by unseating and seating of the valve body. A resilient member generates a resilient force to urge the valve body toward the seating surface. A seat angle is an angle between two straight lines appearing in a cross section of the seating surface, the cross section including a center axis of the valve body. The seat angle is 90 degrees or less.

A fuel injection valve includes: a circular plate portion that is abuttable against an end surface of a needle opposite from a valve seat while the needle being provided to open and close an injection hole upon lifting and seating of the needle relative to the valve seat; and a tubular portion that extends from the circular plate portion toward the valve seat and has an end part, which is opposite from the circular plate portion and is abuttable against a movable core second contact surface of a movable core opposite from the valve seat. In a state where the circular plate portion abuts against the needle, and the tubular portion abuts against the movable core, a gap is formed between a flange member end surface of a flange of the needle and a movable core first contact surface of the movable core opposite from the valve seat.

A fuel injector includes a housing extending along an injector axis. A pintle has an axially extending pintle shaft and a radially projecting annular collar with a collar surface, the pintle being axially moveable between an open position and a closed position. An armature is axially guided in the housing between a proximal position and a distal position, the armature having an axial through-hole in which the pintle shaft is guided and an armature surface which engages the collar surface, thereby moving the pintle into the open position when the armature moves to the proximal position. A first resilient member biases the pintle in the distal direction and a second resilient member biases the armature in the distal direction. The armature surface and the collar surface are slanted with respect to the injector axis and one of the armature surface and the collar surface is convex curved.

A valve assembly for a fluid injector is disclosed. The valve assembly includes a valve body having a longitudinal axis, an armature, a valve needle having a needle tip and a damping element. The armature and the damping element include penetrating first openings in which the valve needle is arranged. The damping element is fixed to the valve needle and arranged between the armature and the needle tip with respect to the longitudinal axis to attenuate a movement of the valve needle relative to the valve body during the operation of the valve assembly.

A gap forming member has: a plate portion that is placed on an opposite side of a needle, which is opposite from a valve seat; and an extending portion that is formed to extend from the plate portion toward the valve seat, while an opposite end part of the extending portion, which is opposite from the plate portion, is contactable with a movable core. A first wall surface of the gap forming member, which is a wall surface opposed to an outer wall of the flange, is slidable relative to the outer wall of the flange, and a second wall surface of the gap forming member, which is a wall surface opposed to an inner wall of a stationary core, forms a radial gap, which is a gap in a radial direction, between the second wall surface and the inner wall of the stationary core.

An electromagnetic valve control unit for detecting operation of an electromagnetic valve on the basis of a drive voltage or a drive current applied to the electromagnetic valve. The electromagnetic valve control unit includes an A/D converter, a filter, and a detection unit. The A/D converter converts the drive voltage or the drive current into a digital signal. The filter has a gain of about zero at a predetermined frequency. The detection unit detects operation of the electromagnetic valve on the basis of an output of the filter upon input of the digital signal into the filter.

Some embodiments include: a valve body; a valve needle; a calibration spring biasing the needle to close a fluid outlet; an armature to actuate the needle; and an armature stopper comprising an armature support, a circumferential side wall, and a circumferential clamping portion. The armature stopper is coaxial with the valve needle below the armature, facing the armature and providing a stop for the armature in the closing direction. The clamping portion includes a circumferential gutter formed by a base portion, an inner wall and an outer wall. The inner wall is part of the circumferential side wall with a smaller radial extension than the outer wall and is closer to the valve needle. The outer wall extends circumferentially around the inner wall to form a press-fit area for press-fitting the armature stopper into the valve body.

A valve assembly is provided with a valve body, a valve needle and an armature. An actuator assembly surrounds the valve assembly. The actuator assembly includes a housing and a coil. The coil can be energized so as to induce a force for axially displacing the armature. A flow characteristic of fluid to be injected by the injector is adjusted by axially shifting the valve assembly and the actuator assembly relative to one another.

A dosing unit includes a fluid injector having a valve seat; a valve needle movable within the fluid injector between a closed position in which an end engages with the valve seat to block a flow of fluid from exiting the fluid injector and an open position in which the end is spaced apart from the valve seat so as to allow fluid to exit the fluid injector. The valve body, the valve seat and the valve needle form an outwardly opening valve assembly. A pole piece fixedly is disposed within the valve body, and an armature is coupled to the valve needle upstream of the pole piece. A coil is disposed around the pole piece and the armature so as to generate a force when energized to move the armature toward the pole piece and to cause the valve needle to move from the closed to the open position.

A gap forming member has: a plate portion that is placed on an opposite side of a needle, which is opposite from a valve seat; and an extending portion that is formed to extend from the plate portion toward the valve seat, while an opposite end part of the extending portion, which is opposite from the plate portion, is contactable with a movable core. A first wall surface of the gap forming member, which is a wall surface opposed to an outer wall of the flange, is slidable relative to the outer wall of the flange, and a second wall surface of the gap forming member, which is a wall surface opposed to an inner wall of a stationary core, forms a radial gap, which is a gap in a radial direction, between the second wall surface and the inner wall of the stationary core.