Fuel injector of internal combustion engine, and internal combustion engine

Abstract

To provide a new type fuel injector of an internal combustion engine, and the internal combustion engine with the injector.SOLUTION: A fuel injector (10) of an internal combustion engine comprises: a first nozzle needle (14) interacted with a first fuel injection orifice (16) to open or block a flow of first fuel with comparatively low ignitability passing through the first fuel injection orifice (16); and a second nozzle needle (15) interacted with a second fuel injection orifice (17) to open or block a flow of second fuel for igniting the first fuel with comparatively high ignitability passing through the second fuel injection orifice (17). The first fuel injection orifice (16) is arranged along a pitch circle profile (18), the second fuel injection orifice (17) is arranged along a circular profile (19), and the second fuel injection orifice (17) projects more deeply into a combustion chamber than the first fuel injection orifice (16).SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a fuel injector for an internal combustion engine. Further, the present invention relates to an internal combustion engine having at least one fuel injector.

[0002] The present invention relates in particular to the field of so-called large engines or large internal combustion engines, the cylinders of which have a piston diameter of at least 140 mm, in particular at least 175 mm. Such large internal combustion engines are, for example, ship engines.

Background Art

[0003] Dual-fuel internal combustion engines are already known as ship engines. The actually known dual-fuel internal combustion engines can be operated in a first operating mode in which a first fuel, in particular a fuel with relatively low ignitability, is burned, and a second operating mode in which a second fuel, in particular a fuel with relatively high ignitability, is burned.

[0004] The first fuel with relatively low ignitability can be, for example, methanol, ethanol or ammonia. The second fuel with relatively high ignitability can be, for example, diesel fuel. In the first operating mode, the first fuel with relatively low ignitability, in particular methanol, ethanol or ammonia, can be ignited via the second fuel with relatively high ignitability, in particular diesel fuel.

[0005] Patent Document 1 discloses a fuel injector that can introduce both a first fuel with relatively low ignitability and a second fuel with relatively high ignitability into the combustion chamber of a cylinder in a first operating mode of a dual-fuel internal combustion engine. The fuel injector disclosed therein is embodied as a so-called dual-needle injector having two nozzle needles movably guided in corresponding needle guides. A first fuel injection orifice that interacts with the first nozzle needle and a second fuel injection orifice that interacts with the second nozzle needle are each arranged along a circular contour, and in the installed state of the fuel injector, the first fuel injection orifice and the second fuel injection orifice protrude equally deeply or distantly into the combustion chamber of the cylinder. For this reason, a large restriction occurs when injecting fuel into the combustion chamber of the cylinder, and the combustion space of the combustion chamber cannot be optimally utilized. Therefore, especially in the second operating mode, for example, when only the fuel with relatively high ignitability is burned, a considerable part of the combustion space of the combustion chamber can no longer be filled with the fuel with relatively high ignitability.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The present invention has been made in view of such circumstances, and an object thereof is to provide a fuel injector for a new type of internal combustion engine and an internal combustion engine equipped with the same.

Means for Solving the Problems

[0008] This problem is solved by the fuel injector according to claim 1 and the internal combustion engine according to claim 7.

[0009] The fuel injector includes a first nozzle needle movably guided within a first needle guide, and the first nozzle needle interacts with a first fuel injection orifice so as to open or block a flow of a first fuel having relatively low ignitability passing through the first fuel injection orifice according to its position.

[0010] Furthermore, the fuel injector includes a second nozzle needle movably guided within a second needle guide, and the second nozzle needle interacts with a second fuel injection orifice so as to open or block a flow of a second fuel having relatively high ignitability for igniting the first fuel passing through the second fuel injection orifice according to its position.

[0011] The first fuel injection orifice of the fuel injector is arranged along a pitch circle contour, and the second fuel injection orifice is arranged along a circular contour such that the distance between the center point of the pitch circle contour and the center point of the circular contour is greater than the sum of the radius of the pitch circle contour and the radius of the circular contour.

[0012] In the installed state of the fuel injector, the second fuel injection orifice is deeper or more protruding into the combustion chamber of the cylinder than the first fuel injection orifice.

[0013] In the fuel injector according to the present invention, the fuel injection orifice of the fuel injector for introducing a fuel having relatively high ignitability into the combustion chamber of the cylinder is deeper or more protruding into the combustion chamber of the cylinder than the first fuel injection orifice for introducing a fuel having relatively low ignitability into the combustion chamber of the cylinder in the installed state of the fuel injector. Therefore, both the first fuel having relatively low ignitability and the second fuel having relatively high ignitability can be advantageously introduced into the combustion chamber, and the combustion space of the combustion chamber can be optimally utilized. In particular, when only a fuel having relatively high ignitability is burned in the corresponding operating mode of the internal combustion engine, the fuel having high ignitability can be easily and optimally introduced into the combustion chamber.

[0014] Preferably, the pitch circle profile where the first fuel injection orifice is arranged covers an angular range of 360° to δ, where δ is 15° to 60°, particularly 20° to 60°, preferably 20° to 45°. The pitch circle profile defined by the angle δ faces the circular profile where the second fuel injection orifice is arranged. The circular profile where the second fuel injection orifice is arranged covers an angular range of 360°. Thereby, both the first fuel with relatively low ignitability and the second fuel with relatively high ignitability can be optimally introduced into the combustion chamber of the cylinder.

[0015] Preferably, the ratio of the height offset between the circular profile where the second fuel injection orifice is arranged and the pitch circle profile where the first fuel injection orifice is arranged to the distance between the center point of the pitch circle profile and the center point of the circular profile is 0.1 to 0.4, particularly 0.15 to 0.35, preferably 0.17 to 0.29. This is also advantageous for optimally introducing both the first fuel with relatively low ignitability and the second fuel with relatively high ignitability into the combustion chamber of the cylinder.

[0016] Preferably, the first fuel injection orifice is provided for injecting the first fuel within the first spray cone at the first cone angle into the combustion space, and the second fuel injection orifice is provided for injecting the second fuel within the second spray cone at the second cone angle into the combustion space. The first cone angle is smaller than the second cone angle. The first cone angle is preferably between 66° and 88°, particularly between 68° and 86°, particularly preferably between 70° and 84°. The second cone angle is preferably between 70° and 92°, particularly between 72° and 90°, particularly preferably between 74° and 88°. Thereby, the introduction of the first fuel with relatively low ignitability and the second fuel with relatively high ignitability into the combustion chamber of each cylinder can be further improved.

[0017] A preferred further development of the present invention is obtained from the dependent claims and the following description. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0019] The present invention relates to a fuel injector for an internal combustion engine. Such a fuel injector supplies fuel to the combustion chamber of a cylinder of an internal combustion engine. The fuel injector according to the present invention functions in particular to supply different fuels to an internal combustion engine configured as a dual-fuel internal combustion engine. Thus, in a first operating mode, a first fuel, in particular a fuel with relatively low ignitability, and a second fuel with relatively high ignitability are introduced, and the first fuel with relatively low ignitability in the first operating mode is ignited via the second fuel with relatively high ignitability. Further, in a second operating mode in which only the second fuel with relatively high ignitability is combusted, the same fuel is injected into the combustion chamber of the cylinder via the fuel injector. The first fuel with relatively low ignitability can be methanol, ethanol or ammonia. The second fuel with relatively high ignitability is in particular diesel fuel.

[0020] Figs. 1 to 3 show different views of a fuel injector 10 according to the present invention. The fuel injector 10 has a body 11 with two needle guides 12, 13.

[0021] A first nozzle needle 14 is movably guided in a first needle guide 12, and a second nozzle needle 15 is movably guided in a second needle guide 13. The first nozzle needle 14 and a first fuel injection orifice 16 interact such that the first nozzle needle 14 opens or blocks the fuel flow of a first relatively low ignitability fuel passing through the first fuel injection orifice 16 according to its position within the first needle guide 12. The second nozzle needle 15 and a second fuel injection orifice 17 interact such that the second nozzle needle 15 opens or blocks the fuel flow of a second relatively high ignitability fuel according to its position within the second needle guide 13, and acts to ignite the first relatively low ignitability fuel in a corresponding operating mode of the internal combustion engine via the second fuel injection orifice 17.

[0022] Therefore, when the internal combustion engine is operated in an operating mode in which a first relatively low ignitability fuel is combusted and ignited with the assistance of a second relatively high ignitability fuel, the first relatively low ignitability fuel is introduced into the combustion chamber of the cylinder via the first fuel injection orifice 16, and the second relatively high ignitability fuel is introduced into the combustion chamber of the cylinder via the second fuel injection orifice 17. In a second operating mode of the internal combustion engine, when only a second relatively low ignitability fuel is combusted, fuel is introduced into the combustion chamber of the cylinder via the second fuel injection orifice 17, and the first fuel injection orifice 16 is permanently closed by the first nozzle needle 14.

[0023] The first fuel injection orifice 16 is arranged along a pitch circle contour 18, and the second fuel injection orifice 17 is arranged along a circular contour 19. The radius of the pitch circle contour 18 is r1, and the radius of the circular contour 19 is r2. The distance x between the center point 20 of the pitch circle contour 18 and the center point 21 of the circular contour 19 is greater than the sum of the two radii r1 and r2.

[0024] Therefore, the pitch circle contour 18 and the circular contour 19 are not arranged concentrically and do not intersect each other.

[0025] And in the state where the fuel injector 10 is installed, the second fuel injection orifice 17 is disposed deeper in the combustion chamber of the cylinder than the first fuel injection orifice 16. In FIG. 1, the height offset h visualizes the distance from the plane of the circular contour 19 to the plane of the pitch circle contour 18. Accordingly, the circular contour 19 having the second fuel injection orifice 17 protrudes deeper or further into the combustion chamber of the cylinder by the height offset h than the pitch circle contour 18 having the first fuel injection orifice 16 in the installed state of the fuel injector 10.

[0026] The angular range of the circular contour 19 in which the second fuel injection orifice 17 is disposed is 360°. The second fuel injection orifices 17 are preferably, but not limited to, arranged at equidistant intervals on this circular contour 19. Thereby, the second fuel having relatively high ignitability can be injected into the combustion chamber through the second fuel injection orifice 17 in an angular range of 360°.

[0027] The angular range of the pitch circle contour 18 in which the first fuel injection orifice 16 is disposed is 360° - δ. δ is between 15° and 65°, particularly between 20° and 60°, and particularly preferably between 20° and 45°. Accordingly, δ defines the remaining pitch circle contour where the first fuel injection orifice 16 is not disposed. On the pitch circle contour 18, the first fuel injection orifices 16 are preferably, but not exclusively, arranged at equidistant intervals. The remaining pitch circle contour defined by δ where the first fuel injection orifice 16 is not disposed faces the circular contour 19 where the second fuel injection orifice 17 is disposed.

[0028] Preferably, the ratio h / x of the height offset h between the circular contour 19 where the second fuel injection orifice 17 is disposed and the pitch circle contour 18 where the first fuel injection orifice 16 is disposed, and the distance x between the center point 20 of the pitch circle contour 18 and the center point 21 of the circular contour 19 is 0.1 to 0.4, particularly 0.15 to 0.35, and preferably 0.17 to 0.29.

[0029] As already explained, the height offset h is the distance between the plane of the circular contour 19 in which the second fuel injection orifice 17 is arranged and the plane of the pitch circle contour 18 in which the first fuel injection orifice 16 is arranged. The distance x corresponds to the distance between the center point 20 of the pitch circle contour 18 and the center point 21 of the circular contour 19.

[0030] As already explained, the first fuel injection orifice 16 is equipped to inject a first fuel with relatively low ignitability into the combustion chamber of the cylinder, i.e., using a first spray cone characterized by a cone angle β. This cone angle β corresponds to the angle between the side surface of the spray cone and its longitudinal central axis. The second fuel injection orifice 17 is provided to inject a second fuel with relatively high ignitability into the combustion chamber with a second spray cone having a second cone angle α, and the second cone angle α is equal to the angle between the side surface of the second spray cone and its longitudinal central axis.

[0031] The first cone angle β is smaller than the second cone angle α. In particular, the first cone angle β is between 66° and 88°, especially between 68° and 86°, and particularly preferably between 70° and 84°. The second cone angle α is between 70° and 92°, especially between 72° and 90°, and particularly preferably between 74° and 88°.

[0032] The present invention enables optimal introduction of fuel into the combustion chamber of the cylinder in different operating modes of an internal combustion engine preferably configured as a dual-fuel internal combustion engine. Thus, in the first operating mode, both the first fuel with relatively low ignitability and the second fuel with relatively high ignitability for igniting it can optimally introduce and burn the second fuel with relatively high ignitability into the combustion chamber of the cylinder, similar to the second operating mode.

Explanation of Reference Signs

[0033] 10 Fuel injector 11 Body 12 First needle guide 13 Second needle guide 14 First nozzle needle 15 Second nozzle needle 16 First fuel injection orifice 17 Second fuel injection orifice 18 Pitch circle contour 19 Circular contour 20, 21 Center point

Claims

1. 1. A fuel injector (10) for an internal combustion engine for supplying fuel to a combustion chamber of a cylinder of the internal combustion engine, comprising: a first nozzle needle (14) movably guided in a first needle guide (12) and interacting with a first fuel injection orifice (16) in such a way that, depending on its position, the first nozzle needle (14) opens or blocks the flow of a first, relatively low-ignition fuel through the first fuel injection orifice (16); a second nozzle needle (15) movably guided in a second needle guide (13) and interacting with the second fuel injection orifice (17) in such a way that, depending on its position, the second nozzle needle (15) opens or blocks the flow of a second, relatively ignitable fuel through the second fuel injection orifice (17) for igniting the first fuel; Equipped with - said first fuel injection orifice (16) is arranged along a pitch circle contour (18) and said second fuel injection orifice (17) is arranged along a circular contour (19) such that the distance (x) between the centre point (20) of said pitch circle contour (18) and the centre point (21) of said circular contour (19) is greater than the sum of the radius (r1) of said pitch circle contour (18) and the radius (r2) of said circular contour (19); in the installed state of the fuel injector, the second fuel injection orifice (17) projects deeper or further into the combustion chamber of the cylinder than the first fuel injection orifice (16); Fuel injectors.

2. 2. The fuel injector according to claim 1, wherein the circular contour (19) on which the second fuel injection orifices (17) are arranged covers an angular range of 360[deg.].

3. 3. The fuel injector according to claim 1 or 2, wherein the pitch circle contour (18) on which the first fuel injection orifices (16) are arranged covers an angular range of 360° to δ, δ being 15° to 60°, in particular 20° to 60°, preferably 20° to 45°, and the remaining pitch circle contour defined by δ, on which the first fuel injection orifices (16) are not arranged, faces a circular contour (19) on which the second fuel injection orifices (17) are arranged.

4. 4. A fuel injector according to claim 1, 2 or 3, wherein the ratio of a height offset (h) between the circular contour (19) on which the second fuel injection orifices (17) are arranged and the pitch contour (18) on which the first fuel injection orifices (16) are arranged to a distance (x) between a center point (20) of the pitch contour (18) and a center point (21) of the circular contour (19) is 0.1 to 0.4, in particular 0.15 to 0.35, preferably 0.17 to 0.

29.

5. the first fuel injection orifice (16) for injecting the first fuel in a first spray cone at a first cone angle (β) into the combustion space; the second fuel injection orifice (17) for injecting the second fuel in a second spray cone at a second cone angle (α) into the combustion space; A fuel injector according to any one of claims 1 to 4, wherein the first cone angle (β) is smaller than the second cone angle (α).

6. the first cone angle (β) is between 66° and 88°, in particular between 68° and 86°, preferably between 70° and 84°, Fuel injector according to any one of the preceding claims, wherein the second cone angle (α) is between 70° and 92°, in particular between 72° and 90°, preferably between 74° and 88°.

7. a cylinder equipped to ignite a first fuel with the assistance of a second fuel, the cylinder being for combusting the first fuel therein; An internal combustion engine, wherein each cylinder is equipped with a fuel injector (10) according to any one of the preceding claims.

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