Abstract: A fluid injector has a housing, an actuator unit and a valve body. The valve body has a needle (22) and a cartridge (21) with a recess, which takes in the needle (22) and which has on one of its ends a seat plate (213), that has a needle seat (2132) for the inward-opening needle (22), with the needle (22) further having a seat part (221) with a sealing area (222), that is destined to rest on the needle seat (2132) if it is pushed against the needle seat (2132), with the seat part (221) having a cavity radially inwards and in proximity to the sealing area (222).

Abstract: A fluid injector has a valve body with a recess in which a valve needle is arranged axially movable preventing a fluid flow and being mechanically coupled to an axial end of a first spring preloaded to exert a force on the valve needle. A first armature is mechanically coupled to the valve needle. A second armature is arranged in the recess axially movable away and towards a protrusion of the valve body mechanically coupled to an axial end of a second spring preloaded exerting a force on the second armature which is arranged and designed such that from a closing to a first given position, the first and second armature are mechanically decoupled, and from the first given position further away from the closing position, the first and second armature are mechanically coupled. A solenoid drive magnetically actuates the first and second armature to move axially.

Abstract: A fluid injector has a valve body with a recess in which a valve needle is arranged axially movable preventing a fluid flow and being mechanically coupled to an axial end of a first spring preloaded to exert a force on the valve needle. A first armature is mechanically coupled to the valve needle. A second armature is arranged in the recess axially movable away and towards a protrusion of the valve body mechanically coupled to an axial end of a second spring preloaded exerting a force on the second armature which is arranged and designed such that from a closing to a first given position, the first and second armature are mechanically decoupled, and from the first given position further away from the closing position, the first and second armature are mechanically coupled. A solenoid drive magnetically actuates the first and second armature to move axially.

Abstract: A fluid injector has a housing, an actuator unit and a valve body. The valve body has a needle (22) and a cartridge (21) with a recess, which takes in the needle (22) and which has on one of its ends a seat plate (213), that has a needle seat (2132) for the inward-opening needle (22), with the needle (22) further having a seat part (221) with a sealing area (222), that is destined to rest on the needle seat (2132) if it is pushed against the needle seat (2132), with the seat part (221) having a cavity radially inwards and in proximity to the sealing area (222).

Abstract: Magnetic force is increased for faster opening by providing two axial gaps, namely a radially inner gap and a radially outer gap, between the stator and the armature. When the fuel injector opens, impact of the armature with the stator occurs at the inner gap. The maximum radial extent of the armature is less than the radial dimension of the stator housing cavity containing the solenoid coil. The outer gap is defined between the margin of a magnetic pole washer that surrounds a central through-hole in the pole washer and a circular flange of the armature. The inner gap is defined between a ring-shaped upper end face of the armature and a ring-shaped lower end face of a tubular central magnetic pole that extends coaxially through the stator housing to the vicinity of the through-hole in the magnetic pole washer.