Nozzle head and fluid injection valve

1. A nozzle head for atomizing a fluid for a fluid injection valve with a valve body, through which flow can pass, the nozzle head comprising:

a longitudinal axis; and

a nozzle perforated disk having a front surface and an opposite inner surface and a nominal thickness (W 1 ), the inner surface defining a valve seat providing a stop for a needle of the fluid injection valve, wherein the needle obstructs flow of the fluid through the valve body in a closed position bearing against the valve seat;

wherein the nozzle perforated disk comprises two or more nozzle hole channels completely penetrating the nozzle perforated disk,

wherein each nozzle hole channel includes a channel entry at a first channel end and a channel outlet at a second channel end facing away from the first channel end, wherein the channel entry is formed on the inner surface of the nozzle perforated disk,

a nozzle hole projection of each nozzle hole channel includes a channel wall having a wall height (h) extending beyond the nominal thickness (W 1 ) of the nozzle perforated disk, starting from the front surface, in a direction along the longitudinal axis and is configured over a circumference of said each nozzle hole channel so that the second channel end corresponds to a channel wall end of the channel wall configured so as to face away from the front surface,

wherein each nozzle hole projection has a hollow frustoconical shape defining a tapered outer circumferential surface and a tapered inner surface, both extending along the full wall height (h) of the nozzle hole projection, and both narrowing along a direction away from the front surface of the nozzle perforated disk,

at an axial distance (W 2 ) from the front surface along the longitudinal axis, a free radial distance D is formed between adjacent nozzle hole channels of the two or more nozzle hole channels, wherein:

h≥ ¼· D ; and

the axial distance (W 2 ) corresponds to the wall height (h); and

wherein the channel outlets at the second channel end of each nozzle hole channel define a total outlet area from the nozzle perforated disk suitable for atomizing the fluid passing through the valve body.

2. The nozzle head as recited in claim 1 , wherein the channel outlet is smaller than the channel entry.

3. The nozzle head as recited in claim 1 , wherein the wall height h=¼·D.

4. The nozzle head as recited in claim 1 , wherein the circumferential surface of each nozzle hole projection has a contour formed in a longitudinal section in accordance with a continuously differentiable function.

5. The nozzle head as recited in claim 4 , wherein each said outer circumferential surface is ramp shaped.

6. A fuel injection valve configured to inject a fuel into a combustion chamber of an internal combustion engine, the fuel injection valve comprising:

a valve body having a fuel inlet and a fuel outlet;

a needle movable within the valve body;

a nozzle head for atomizing the fuel into the combustion chamber of the internal combustion engine, the nozzle head arranged at the fuel outlet and having a front surface facing away from the fuel inlet and an inner surface facing the fuel inlet,

the nozzle head comprising:

a longitudinal axis; and

a nozzle perforated disk having a front surface and an opposite inner surface and a nominal thickness (W 1 ), the inner surface defining a valve seat providing a stop for the needle, wherein the needle obstructs flow of the fluid through the valve body in a closed position bearing against the valve seat;

wherein the nozzle perforated disk comprises two or more nozzle hole channels completely penetrating the nozzle perforated disk,

wherein each nozzle hole channel includes a channel entry at a first channel end and a channel outlet at a second channel end facing away from the first channel end, wherein the channel entry is formed on the inner surface of the nozzle perforated disk,

a nozzle hole projection of each nozzle hole channel includes a channel wall having a wall height (h) extending beyond the nominal thickness (W 1 ) of the nozzle perforated disk, starting from the front surface, in a direction along the longitudinal axis and is configured over a circumference of said each nozzle hole channel so that the second channel end corresponds to a channel wall end of the channel wall configured so as to face away from the front surface,

wherein the nozzle hole projection has a hollow frustoconical shape defining a tapered circumferential outer surface and a tapered inner surface, both extending along the full wall height h of the nozzle hole projection, and both narrowing along a direction away from the front surface of the nozzle perforated disk,

at an axial distance (W 2 ) from the front surface along the longitudinal axis, a free radial distance D is formed between adjacent nozzle hole channels of the two or more nozzle hole channels, wherein:

h≥ ¼· D ; and

the axial distance (W 2 ) corresponds to the wall height (h).

7. The fuel injection valve as recited in claim 6 , wherein the channel outlet is smaller than the channel entry.

8. The fuel injection valve as recited in claim 6 , wherein the wall height h=¼·D.

9. The fuel injection valve as recited in claim 6 , wherein the circumferential surface of each of said nozzle hole projections has a contour formed in a longitudinal section in accordance with a continuously differentiable function.

10. The fuel injection valve as recited in claim 9 , wherein the respective circumferential surface of each of said nozzle hole projections is ramp shaped.

11. A fuel injection valve configured to inject a fuel into a combustion chamber of an internal combustion engine, the fuel injection valve comprising:

a valve body through which the fuel can pass;

a needle movable within the valve body;

a nozzle head for atomizing the fuel into the combustion chamber of the internal combustion engine, the nozzle head arranged at an outlet end of the valve body opposite a fuel supply end and downstream from the valve seat and the needle, the nozzle head comprising:

a longitudinal axis; and

a nozzle perforated disk having a front surface and an opposite inner surface and a nominal thickness (W 1 ), the inner surface defining a valve seat providing a stop for a needle of the fluid injection valve, wherein the needle obstructs flow of the fluid through the valve body in a closed position bearing against the valve seat;

wherein the nozzle perforated disk comprises two or more nozzle hole channels completely penetrating the nozzle perforated disk,

wherein each nozzle hole channel includes a channel entry at a first channel end and a channel outlet at a second channel end facing away from the first channel end, wherein the channel entry is formed on the inner surface of the nozzle perforated disk,

a nozzle hole projection of each nozzle hole channel includes a channel wall having a wall height (h) extending beyond the nominal thickness (W 1 ) of the nozzle perforated disk, starting from the front surface, in a direction along the longitudinal axis and is configured over a circumference of said each nozzle hole channel so that the second channel end corresponds to a channel wall end of the channel wall configured so as to face away from the front surface,

wherein the nozzle hole projection has a hollow frustoconical shape defining a tapered circumferential outer surface and a tapered inner surface, both extending along the full wall height (h) of the nozzle hole projection, and both narrowing along a direction away from the front surface of the nozzle perforated disk,

at an axial distance (W 2 ) from the front surface along the longitudinal axis, a free radial distance D is formed between adjacent nozzle hole channels of the two or more nozzle hole channels, wherein:

h≥ ¼· D ; and

the axial distance (W 2 ) corresponds to the wall height (h); and

wherein the channel outlets at the second channel end of each nozzle hole channel define a total outlet area from the nozzle perforated disk suitable for atomizing the fluid passing through the valve body.