In a fuel injection valve, a movable structure includes: a movable core that includes a first attractive surface and a second attractive surface, which are configured to be attracted toward at least one stationary core when a coil is energized; and an elongated shaft member that has a length, which is measured in a moving direction of the movable structure and is larger than a length of the movable core, which is measured in the moving direction. A modulus of longitudinal elasticity of the elongated shaft member is larger than a modulus of longitudinal elasticity of the movable core.

A fuel injector is provided. The fuel injector includes a sleeve having a first end proximate an outlet; a piston slidingly received in the sleeve, the piston having a first end proximate the outlet; a pumping chamber at least partially defined by the sleeve between the first end of the piston and the outlet; and a normally-open inlet valve through which fuel passes to enter the pumping chamber.

A movable core is driven by a magnetic attraction force with a fixed core to move a valve body to inject fuel. A yoke accommodates the fixed core. A coil is in a coil chamber between the fixed core and the yoke. The coil chamber is filled with a filling resin member being electrically insulative. The fixed core has a core facing surface facing the movable core and includes a protruding portion that protrudes radially outer side and is in contact with the yoke to conduct the magnetic flux. A resin molding flow channel is formed in the protruding portion to cause molten resin serving as the filling resin member to flow into the coil chamber. A length of the protruding portion along a cylinder center line is set to be shorter toward a radially outer side.

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.

An injector for injecting fuel, which is introduced from a fuel rail, into an engine to supply the fuel thereto is provided. In particular, the injector includes a housing, an electromagnetic generation unit accommodated in the housing and formed to generate an electromagnetic field when electric power is applied thereto, a core inserted into a fuel-rail-side end of a bobbin to form a magnetic circuit using the generated electromagnetic field, a lead pipe inserted into an engine-side end of the bobbin to form the magnetic circuit by coupling with the core, a molding unit formed to enclose the electromagnetic generation unit and an outer peripheral surface of the core to block introduction of moisture, and a cover coupled to the outer peripheral surface of the core to constitute the magnetic circuit together with the core.

A fuel injector is provided. The fuel injector includes a sleeve having a first end proximate an outlet; a piston slidingly received in the sleeve, the piston having a first end proximate the outlet; a pumping chamber at least partially defined by the sleeve between the first end of the piston and the outlet; and a normally-open inlet valve through which fuel passes to enter the pumping chamber.

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 fluid injector for a combustion engine has a tubular body which hydraulically connects a fluid inlet end of the injector to a fluid outlet end of the injector. A magnetic core is affixed inside the body, a solenoid is disposed on the outside of the body, and an axially moveable armature is disposed inside the body. A valve assembly controls an axial flow of fluid through the body. The valve assembly has a valve needle to be operated by the armature and a sleeve of diamagnetic material which is located radially between the armature and the body.

In general, the subject matter described in this disclosure can be embodied in a fuel injector that includes an upper housing portion that defines an inlet passage adapted to receive fuel, and a lower housing portion that is attached to the upper housing portion and that defines an injector outlet adapted to dispense fuel. The fuel injector includes an electromagnetic coil assembly that is user removable while the upper housing portion remains attached to the lower housing portion. The fuel injector includes a movable pintle that is biased to a closed position that is adapted to prevent fuel from flowing through the injector outlet, and movable, responsive to magnetic force produced by energizing the electromagnetic coil assembly, to an open position that is adapted to permit fuel to flow through the injector outlet.

In an electromagnetic fuel injection which is structured such that both end surfaces of an inner circumferential iron core portion and an outer circumferential iron core portion face a movable iron core, and a non-magnetic portion made of a metal material is provided between both end surfaces, an object of the present invention is to realize a structure of the electromagnetic fuel injector in which a surface of a target object is unlikely to be affected by a heat treatment with the surface facing the movable iron core. In an electromagnetic fuel injector 1 of the present invention which is structured such that both end surfaces of an inner circumferential iron core portion 401a and an outer circumferential iron core portion 401b face a movable iron core 402, and a non-magnetic portion 401d made of a metal material is provided between both end surfaces, in order to achieve this object, heat in a target member to be heat treated is generated by applying energy to a target member's surface which is different from a target member's surface that faces the movable iron core 402. More preferably, energy is applied to a surface different from a surface on a side that faces the movable iron core 402.