A method for producing a nozzle body for a fluid injection valve includes supplying a nozzle body blank having a nozzle body tip and introducing a nozzle body recess into the nozzle body blank, starting from a first axial end, and thereby forming a wall. The method furthermore includes supplying geometry data of at least one injection hole to be provided, with an inner opening and an outer opening, and determining a height of a blind hole step of a blind hole to be formed, in a manner dependent on a predefined fluid penetration. The method furthermore includes adapting a part of the shape of an inner surface of the wall and thereby forming the blind hole with the blind hole step of the determined height and introducing the at least one injection hole with the supplied geometry data, so that the at least one injection hole penetrates the wall.

A fuel injector, comprising a nozzle body having a proximal end and a distal end, an upper row of nozzle holes being equally spaced about a first circumference of the nozzle body, and a lower row of nozzle holes located between the distal end and the upper row of nozzle holes, wherein the upper row has a first number of holes that is greater than a second number of holes in the lower row and wherein one of the first number of holes and the second number of holes is odd.

A nozzle plate for a fuel injection device opposes a fuel injection port of a fuel injection device. A nozzle hole through which fuel injected from the fuel injection port passes is formed at the nozzle plate. At this nozzle plate for the fuel injection device, the nozzle hole has a fuel-flow-in-side opening end with a circular shape. The nozzle hole is coupled to the fuel injection port via fuel guide channels. The fuel guide channels have an opening into the nozzle hole, and a pair of opposing channel sidewalls. The opening has a channel width smaller than a hole diameter of the nozzle hole. One of the opposing channel sidewalls is formed to extend in a tangential direction of the nozzle hole. The fuel is directly flowed into the nozzle hole to generate a flow of the fuel in a spiral pattern in the nozzle hole.

An object of the present invention is to provide a fuel injection valve capable of suppressing fuel adhesion to a nozzle surface. Therefore, an injection hole 107 has a curved surface portion 107E formed between a peripheral edge 107I of an inlet opening 107G and an inner peripheral surface 107F. The curved surface portion 107E has a center-side curved surface portion 107AE and an outer-peripheral-side curved surface portion 107BE. The center-side curved surface portion 107AE is formed to have a width W107AE that is larger than the width W107BE of the outer-peripheral-side curved surface portion 107BE.

A fuel injector, comprising a nozzle body having a proximal end and a distal end, an upper row of nozzle holes being equally spaced about a first circumference of the nozzle body, and a lower row of nozzle holes located between the distal end and the upper row of nozzle holes, wherein the upper row has a first number of holes that is greater than a second number of holes in the lower row and wherein one of the first number of holes and the second number of holes is odd.

An atomizer of a fuel electro-injector is equipped with a nozzle and a valve needle having a head, which is coupled to a sealing seat of the nozzle, and stem, which engages an inner seat of the nozzle; the stem and the nozzle define an annular passageway with a chamber that axially terminates at the sealing seat; the stem has an intermediate portion coupled in an axially sliding manner in the inner seat and defining a plurality of channels, the outlets of which are arranged on the annular chamber; the sealing seat and the head of the valve needle define a discharge section, which is annular and has a width that increases as the opening stroke of the valve needle proceeds; the ratio between the depth and the outer chord of the minimum cross-section of the channels is greater than or equal to two.

A diesel engine includes a piston, a cylinder head, and a fuel injector. The fuel injector has a valve body with bored nozzle holes in its tip part. A cavity having a circular shape in plan view is formed in a crown surface of the piston to concave to the counter cylinder head side. A wall surface constituting the cavity has a central ridge portion bulging toward the fuel injector while bulging larger toward the center of the cavity, a periphery concave portion formed radially outward of the central ridge portion to concave radially outward, and a lip portion formed between the periphery concave portion and the crown surface to convex radially inward. A lip radius R, a nozzle hole length L, a nozzle hole diameter D, and a bore radius B are designed to satisfy the following equation:
99.4D(13D)(L+2.7)Rmin{237.1D(13D)(0.8L+1),2B/3}.

In a fuel injector 10, a first injection hole 155a and a second injection hole 155b having reference inside diameters Dn1, Dn2 different from each other are formed as a plurality of injection holes 155. In such a configuration, an L/D value obtained by dividing the flow channel length Ln1 of the first injection hole 155a by the reference inside diameter Dn1 of the first injection hole 155a agrees to an L/D value obtained by dividing the flow channel length Ln2 of the second injection hole 155b by the reference inside diameter Dn2 of the second injection hole 155b.

A fuel injection nozzle disposed in a center of a reentrant cavity combustion chamber has first and second nozzle hole groups whose inclination angles with respect to a cylinder center axis line are different. A nozzle hole diameter of the second nozzle hole group is larger than that of the first one. First and second nozzle holes are alternately arranged in a circumferential direction. A glow plug projects, in a height direction of the cylinder, up to a height of a spray center axis line (F2) of the second nozzle hole directed at a lower side. Therefore the glow plug can contact fuel masses formed by sprays from both the first and second nozzle holes. The glow plug is positioned between spray center axis lines (F1, F2) in the circumferential direction, and positioned at a swirl downstream side of spray center axis line (F2).

An object of the present invention is to further improve the characteristic of the fuel spray of a fuel injection valve which has a plurality of stepped injection holes having a hole diameter of an outlet side injection hole larger than a hole diameter of an inlet side injection hole and which injects fuel from the stepped injection holes into a cylinder of an internal combustion engine. A cutout portion, which guides a flow of gas flowing into an outlet side injection hole from a lateral position of a fuel outlet of the outlet side injection hole during fuel injection, in a circumferential direction of the outlet side injection hole, is provided for at least one of both lateral portions between which the fuel outlet is interposed along with an arrangement direction of a plurality of injection holes, on a circumferential edge of the fuel outlet of the outlet side injection hole, in relation to at lease some of the injection holes of a fuel injection valve having the plurality of stepped injection holes.