Provided is a structure capable of reducing dribbling of fuel generated when a valve body is closed. In order to achieve the above object, a fuel injection device includes: a valve body; and a seat member having a seat portion on which the valve body is seated and having a fuel injection hole formed on a downstream side of the seat portion. The seat member is formed such that a gap between the seat member and the opposing valve body in the whole region on the downstream side of the fuel injection hole is smaller than a diameter of the fuel injection hole.

In an electromagnetic fuel injection valve for in-cylinder injection, a fuel injection hole is an elongated hole having a major axis and a minor axis, the major axis being curved into an arc shape having a radius that is smaller than a radius of a pitch circle of an inlet of the fuel injection hole. Accordingly, the electromagnetic fuel injection valve can ensure a required flow rate even when a penetrating power is decreased.

A fuel injection valve includes a body that includes an injection hole through which fuel is injected, and a valve element that opens or closes the injection hole. The body includes a metallic base material configured to form the injection hole, a corrosion-resistant layer covering a surface of at least a part of the base material that forms the injection hole and being made of a less corrosive material than the base material, and a sacrificial corrosion layer located between the base material and the corrosion-resistant layer and made of a more corrosive material than the corrosion-resistant layer.

A fuel system for an internal combustion engine includes a pressurized fuel supply, and a fuel injector fluidly connected to the pressurized fuel supply. The fuel injector includes a valve seat plate forming a valve seat, an injection control valve, and a nozzle cavity. A filter, which can include a 2-dimensional filter, is positioned partially within the valve seat plate and partially within an injector body to filter an incoming flow of high-pressure fuel. The valve seat plate and filter are integrated in a valve seat plate and filter assembly.

A movable core is movable relative to a needle main body of a needle. A stationary core is placed on an opposite side of the movable core, which is opposite from a valve seat. A spring is operable to urge the needle and the movable core toward the valve seat. A spring seat is shaped into a ring form and is placed on a radially outer side of the needle main body at the valve seat side of the movable core. The spring is placed between the movable core and the spring seat and is operable to urge the movable core toward the stationary core. A guide is placed on the valve seat side of the movable core in an inside of a housing. An outer wall of the spring seat is slidable relative to an inner wall of the guide to guide reciprocation of the needle.

A needle includes a first seal portion, which is formed at an end portion of the needle located on a side where an injection hole is placed, and a second seal portion, which is formed on a side of the first seal portion where a stationary core is placed. When a boundary between a first outer wall of the first seal portion and a second outer wall of the second seal portion is lifted away from or is seated against an inner wall, the injection hole is opened or closed. Thereby, a seat diameter of the boundary and the inner wall is stabilized, and a change in a fuel injection quantity caused by aging can be reduced. Furthermore, the first outer wall of the first seal portion is shaped into a form of a spherical surface.

The present application concerns a fuel-injection metering device for a motor vehicle. The fuel-injection device include a main body with at least one through-hole, whereby the main body forms a valve seat on its inner face that is provided to interact with a valve body, whereby the inner face of the main body is electrochemically machined. The application also concerns a mold, a production method, and a fuel-injection nozzle.

A fuel system includes a fuel injector having a fuel passage and a purging fluid passage formed therein. A nozzle tip inner surface defines a sac forming a blind end of the fuel passage in the fuel injector. A coaxial concentric check assembly includes a purging check movable to admit a purging fluid such as pressurized air into the fuel passage to purge the sac of fuel. Reduced injector dribble is observed from the purging of fuel.

A valve (or fuel injector), which provides that the valve-seat member exhibits high structural strength and fatigue strength under vibratory stresses, includes an excitable actuator for actuating a valve-closing member which, with a valve-seat face on the valve-seat member, forms a sealing seat, and injection openings which are downstream of the valve-seat face, the injection openings being in a center area of the valve-seat member projecting outwardly dome-like in the injection direction. The dome-like center area has a curved outer contour, the curvature in a radially inner section having a larger radius than the radius of the curvature in a radially outer section of the dome, which ends radially outside the mouth areas of all injection openings, in a recessed depression, that is followed radially outwardly by an axially projecting edge area of the valve-seat member. The fuel injector directly injects fuel into a combustion chamber of an engine.

A nozzle plate is to be attached to a fuel injection port of a fuel injection device and injects fuel from the fuel injection port into an intake pipe through nozzle holes. The outlet side openings of the nozzle holes are partially blocked by interference bodies to determine the fuel injection directions and form orifices for reducing flows of the fuel at the outlet side openings. The plurality of orifices have different fuel injection directions, fuel fine particles in sprays draw ambient air, and the drawn air is provided with kinetic momentum to generate a spiral air flow. The nozzle plate is formed by cooling and solidifying molten resin having filled the cavity of a die.