A fuel injection valve includes a valve housing having an injection hole and a valve seat surface tapering toward a downstream side, a valve component that is accommodated in the valve housing and is coaxially separated from or seated on the valve seat surface, and an elastic component biasing the valve component toward the valve seat surface. The valve component includes an inner convex surface curved in a partial spherical shape with a predetermined curvature radius, and an outer convex surface that is provided continuously to the outer peripheral side of the inner convex surface and curved in a partial spherical shape having a smaller curvature radius than the inner convex surface. A boundary portion between the inner convex surface and the outer convex surface protrudes toward the valve seat surface so as to be able to be separated from or seated on the valve seat surface.

A needle has a seal portion that contacts a valve seat, and is provided so as to be able to reciprocate inside a valve body. A sack chamber is formed between the seal portion and a recess. A seal portion is formed in a curved shape protruding in the axial direction of the needle. A distance between an inlet intersection and a needle intersection on a same virtual straight line is defined as a distance Dh, and a distance between the recess and the seal portion on an axis of the valve body is defined as a distance Ds. When the seal portion is in contact with the valve seat, the distance Dh is larger than the distance Ds (Dh>Ds).

A mobile valve member designed to be arranged in the nozzle body of a fuel injector, extends along a main axis and includes a piston formed of a first male cylinder of effective diameter forming the top end of the mobile member and of a second cylinder provided with an internal cylindrical bore of the effective diameter and a shutoff member including a male cylindrical shaft of the effective diameter that fits slidingly in the internal bore, and of a member extending as far as a pointed end provided with a mobile seat and forming the bottom end of the mobile member. The mobile member is hydraulically balanced and the length between the top end and the bottom end thereof is variable as a result of the sliding of the cylindrical shaft in the internal bore of the piston.

A fluid injector includes a fluid inlet; a valve seat located downstream of the fluid inlet and having a valve seat aperture extending therethrough; a valve member moveable between a closed position and an open position to control flow through the valve seat aperture; and director plate including a first aperture and a second aperture extending therethrough. A fluid flow channel is formed between the valve seat and the director plate and extends from an inlet end to an outlet end. The first aperture and the second aperture extend through the director plate from the fluid flow channel. The first aperture is located between the inlet end and the second aperture. The fluid flow channel decreases in cross-sectional area from the inlet end toward the first aperture and the fluid flow channel increases in cross-sectional area from the first aperture toward the second aperture.

A fuel injector includes a nozzle body, at least one injection orifice formed through an injection end of the nozzle body, and a tubular valve disposed in a bore of the nozzle body that moves between open and closed positions. Apertures formed through a wall of the tubular valve permit fuel to flow freely between opposite ends and along an inner surface of the valve, regardless of any limitations imposed by an annular gap between the valve and nozzle body. The injector provides exceptionally high fuel flow rates without increasing valve lift or injection orifice size over conventional diesel fuel injectors, making it ideal for synthetic fuels such as DME.

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.

An injector includes a nozzle body extending along a longitudinal axis and at least one spray hole extending through a portion of the nozzle body to output a fluid from the injector. The spray hole includes at least one groove. The groove is configured to facilitate efficient mixing of the fluid with air or other surrounding materials for enhanced performance of the injector and/or other components associated with the injector.

Provided is a fuel injection device that can secure strength capable of withstanding high fuel pressure. In a fuel injection device in which a fuel boundary includes two or more components, two components are press-fitted with an inner diameter and an outer diameter and are brought into contact at a butting surface, abutting welding is performed from a direction nearly parallel to the butting surface, an inner diameter side corner portion of the butting surface of a component to be fitted and press-fitted on an inner diameter side is chamfered longer in a direction perpendicular to the butting surface to increase a welding coupling length than a butting length, welding coupling length is less than welding depth, weld penetration depth is not less than material thickness, and the center of the weld is on a base material side, the outer diameter of which is larger than a joining face.

The invention relates to a pressure regulator for a high-pressure ramp of a system for injecting fuel into an internal combustion engine, comprising a solenoid valve element (10) which receives an electromagnet (40). The electromagnet controls a needle (20) that closes a valve seat (30) which is connected to a high-pressure inlet and opens into a discharge chamber (13), said discharge chamber communicating with a liquid recirculation system (5) by means of outlet openings (14). The rear face (12) of the solenoid valve element (10) receives a coil (40) which controls the opening process of an armature (41) that is rigidly connected to the needle (20) and is subject to a closing return spring (25). The discharge chamber (13) is located on the front face (11) of the solenoid valve element (10) on the axis (XX) of the needle (20), and the discharge chamber surrounds the needle. A cavity (15) passes through the discharge chamber, said cavity receiving an inlet valve element (50), and a bore (51) which opens into the valve seat (30) passes axially through the inlet valve element. The discharge chamber (13) through which the needle (20) passes axially and the outlet openings (14) which are connected to the liquid recirculation system open transversally into a wall (131) in the discharge chamber (13) below the upper part (132) of the chamber. The regulator is characterized that the regulator comprises an annular expansion (70) of the discharge chamber (13) below the outlet openings (14) along the extension of a conical surface (31), which forms the valve seat (30) and an annular dead volume (70), above the surface (54) of the valve element (50), which forms the base of the discharge chamber (13) and has the valve seat (30) in the center of the valve element.

A mobile valve member designed to be arranged in the nozzle body of a fuel injector, extends along a main axis and includes a piston formed of a first male cylinder of effective diameter forming the top end of the mobile member and of a second cylinder provided with an internal cylindrical bore of the effective diameter and a shutoff member including a male cylindrical shaft of the effective diameter that fits slidingly in the internal bore, and of a member extending as far as a pointed end provided with a mobile seat and forming the bottom end of the mobile member. The mobile member is hydraulically balanced and the length between the top end and the bottom end thereof is variable as a result of the sliding of the cylindrical shaft in the internal bore of the piston.