A fuel injection valve includes: a housing that includes an injection hole and a valve seat; a needle that includes a flange at a radially outer side of the needle and opens or closes the injection hole; a movable core that is installed on the valve seat side of the flange; a first spring that urges the needle toward the valve seat side; a second spring that urges the movable core toward an opposite side, which is opposite from the valve seat; and a limiting member that is installed on a radially outer side of the needle such that the limiting member enables movement of the movable core between the limiting member and the flange on the valve seat side of the flange. The limiting member includes an outside projection, which supports the second spring; and a tubular portion and an inside projection, which are contactable with the movable core.

This fuel injection valve is provided with: a valve seat (15b) and a valve body (27c), which cooperate to open and close a fuel passage; a valve seat member (15) having formed thereon the valve seat (15b) and a guide surface (15c) which guides the valve body (27c); and a cylindrical body (5) having the valve seat member (15) press-fitted in the front end-side end thereof. The valve seat member (15) is configured so that the press-fit section (15f) thereof which is press-fitted in the cylindrical body (5) is provided at a position offset toward the base end of the cylindrical body (5) relative to both the valve seat (15b) and the guide surface (15c) in the direction of the center axis (1x) of the fuel injection valve.

Disclosed is a fuel injection valve in which a movable core and a fixed core are enclosed in a cylindrical body. The cylindrical body has an annular groove formed therein, on an outer circumferential side of a region in which the movable core and the fixed core are opposed to each other, to define a thin portion of small wall thickness. In a cross section taken along a center axis of the fuel injection valve, the thin portion has curved line sections on both end sides thereof in a direction along the center axis such that the curved line sections respectively connect a bottom of the annular groove to side edges of the annular groove by curved lines. The curved line sections are provided over a range of larger dimension, from the respective side edges in the direction along the center axis, than a depth dimension of the annular groove.

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.

An injection device for metering a fluid, having the following: a valve, which has a valve needle and a valve seat; a nozzle shaft, which surrounds the valve needle and which holds a volume of the fluid; and an inlet chamber, which adjoins the nozzle shaft on the side of the nozzle shaft facing away from the valve and which has a flow connection to the nozzle shaft. The injection device has at least one compressible volume compensation element, which is filled with a gas and which, within the injection device, is in contact with the fluid.

A fluid injector assembly extending along a longitudinal axis comprising a housing, and an injector positioned within the housing, the injector comprising a injector body having an interior cavity, a plunger positioned within the interior cavity and comprising a plunger body, a fluid delivery passage along at least a portion of the plunger body, and a plunger tip positioned at a downstream end of the plunger body, the fluid delivery passage comprising a longitudinal passage and at least one internal swirl passage, and the internal swirl passage being angled relative to the longitudinal axis and extending from the longitudinal passage to an opening upstream of the plunger tip, and a nozzle positioned at a downstream end of the injector body and including at least one nozzle passage, fluid being delivered from an upstream end of the injector to the at least one nozzle passage through the fluid delivery passage.

An injector includes a needle and a body. The needle is configured to receive fluid from a fluid supply and operable between a first position, in which the fluid is not provided to a target, and a second position, in which the fluid is provided to the target. The needle includes a first needle bore, a second needle bore, and a first connector. The first needle bore is configured to receive fluid from the fluid supply. The second needle bore is aligned with the first needle bore and configured to provide fluid to the fluid supply. The first connector is in fluid communication with the second needle bore. The body includes an end, a first body bore, and a second body bore. The first body bore is configured to receive the needle. The second body bore is positioned to be contiguous with the end.

A metering device for metering water or an aqueous solution, such as an injector for metering a reducing agent liquid into an exhaust gas stream of a combustion system or an injector for metering water or aqueous solution into a combustion chamber or into an intake manifold of an internal combustion engine. The metering device has an inlet and an outlet for the water or aqueous solution and a shut-off device which is arranged between the inlet and the outlet. At least one electrically operated heating element is arranged in the region of the shut-off device so as to heat and avoid freezing of the liquid.

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.

A metering system for a fluid atomizer includes a housing, first and second metering members, and at least one solenoid. The housing includes a mixing chamber. The first metering member is operable to control flow of a first fluid to the mixing chamber. The second metering member is arranged coaxial with the first metering member and operable to control flow of a second fluid to the mixing chamber. The at least one solenoid is configured to operate at least one of the first and second metering members.