A valve assembly for an injection valve is disclosed. The valve assembly includes a valve body having a cavity with a fluid inlet portion and a fluid outlet portion, a valve needle, an armature which is able to slide on the valve needle, and a disc element positioned to limit axial displaceability of the armature relative to the valve needle. The disc element includes a plurality of passages extending in axial direction through a disc-shaped part of the disc element. The passages provide a first flow resistance for a fluid passing in a direction away from the fluid outlet passage and a second flow resistance in a direction towards the fluid outlet passage, wherein the second flow resistance is larger than the first flow resistance.

Provided is a prestroke adjustment method for a fuel injection valve capable of reducing variations in a prestroke amount regardless of the level of machining accuracy of a component. The prestroke adjustment method adjusts a prestroke amount D2 of a fuel injection valve 1 including a gap forming member 50 that forms a gap G2 defining a prestroke between a valve member 30 and engagement portions 33a and 423a of a movable core 42 by a second portion 52a abutting on the movable core 42 in a state where a first portion 51a is positioned at a reference position 33b of the valve member 30. In the prestroke adjustment method, a load L in the direction from the first portion 51a toward the reference position 33b of the valve member 30 is applied to the gap forming member 50 assembled to the valve member 30 to plastically deform the gap forming member 50, thereby shortening the relative length between the first portion 51a and the second portion 52a and setting the prestroke amount D2 to the target value T2.

In a fuel injection device, a driving unit structure has a magnetic aperture, in which an inner diameter is gradually enlarged toward the mover side, provided in an inner peripheral surface of the magnetic core. It is possible to reduce magnetic delay time upon valve opening from the supply of the electric current to the coil to the rise of magnetic flux and magnetic delay time upon valve closing from the stoppage of the electric current to the coil to reduction of magnetic flux, by providing a magnetic aperture in the inner peripheral surface of the magnetic core. Thus it is possible to improve the dynamic responsiveness upon valve opening and valve closing.

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.

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 fuel injection valve includes a valve body, a fixed core, a movable core, a spring and a cup. The movable core has a first core contact surface which contacts the valve body when the movable core is moved by a predetermined distance away from a nozzle hole, and a second core contact surface which contacts the cup when the movable core is moved away from the nozzle hole. The movable core, the cup and the valve body form a fuel storage chamber which is surrounded by the movable core, the cup and the valve body to accumulate fuel. The first core contact surface is located inside the fuel storage chamber. The first core contact surface and the second core contact surface have a communication groove through which the inside and the outside of the fuel storage chamber communicate with each other.

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.

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.

Provided is a fuel injection valve capable of stroking a valve body in two stages of large and small strokes and improving responsiveness of a valve opening operation. Therefore, a first mover 201 is attracted to a magnetic core 107. A second mover 202 is formed separately from the first mover 201, and is attracted to the magnetic core 107 on an inner diameter side of the first mover 201. A valve body 101 has a flange portion 101a on an upstream side of the second mover 202. A spacer 213 forms a gap (void g1) in an axial direction between the flange portion 101a and the second mover 202 in a valve closed state.

Common component parts for an armature-needle assembly for aftermarket fuel injectors are described herein, where the common components include a needle, an armature, an upper stop flange, a lower stop flange, and one or more guide plates, the flanges and guide plates having apertures configured to accept the needle. The common components are capable of being assembled into at least three different armature-needle assemblies—de-coupled, floating, and fixed configurations. Further included are different sleeve configurations that allow for the adjustment to the induction and the ability to utilize a common solenoid in the different aftermarket fuel injector configurations.