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INJECTION NOZZLE, FUEL INJECTOR HAVING INJECTION NOZZLE

20240175415 ยท 2024-05-30

    Inventors

    Cpc classification

    International classification

    Abstract

    The invention relates to an injection nozzle (1) for injecting a fluid, in particular a liquid or gaseous fuel, comprising: a nozzle body (2) which is designed to be hollow-cylindrical at least in portions and forms a sealing seat (3) via which a flow path (4) for the fluid to be injected leads, a nozzle needle (5) which is accommodated in the nozzle body (2) for reciprocating movement and has a sealing surface (6) that interacts with the sealing seat (3), a guide element (7) which is fixedly connected to the nozzle needle (5) and is guided by means of an external guide (8) of the nozzle body (2).

    The invention further relates to a fuel injector having an injection nozzle (1) according to the invention.

    Claims

    1. An injection nozzle (1) for injecting a fluid, the injection nozzle comprising: a nozzle body (2) which is configured to be hollow-cylindrical at least in portions and forms a sealing seat (3) via which a flow path (4) for the fluid to be injected leads, a nozzle needle (5) which is accommodated in the nozzle body (2) for reciprocating movement and has a sealing surface (6) that interacts with the sealing seat (3), wherein the nozzle needle (5) is fixedly connected to a guide element (7) which is guided by an external guide (8) of the nozzle body (2).

    2. The injection nozzle (1) according to claim 1, wherein the external guide (8) and the flow path (4) are spatially separated by the nozzle body (2).

    3. The injection nozzle (1) according to claim 1, wherein an outer peripheral area of the nozzle body (2) forms the external guide (8), and the guide element (7) surrounds the outer peripheral area of the nozzle body (2).

    4. The injection nozzle (1) according to claim 1, wherein the guide element (7) comprises a central recess (9) in which an end portion (10) of the nozzle needle (5) is accommodated.

    5. The injection nozzle (1) according to claim 1, wherein the guide element (7) delimits a flow chamber (11) and comprises at least one opening (12) for discharging the fluid from the flow chamber (11).

    6. The injection nozzle (1) according to claim 1, wherein the sealing seat (3) and/or the sealing surface (6) that interacts with the sealing seat (3) is/are conically shaped.

    7. The injection nozzle (1) according to claim 1, wherein the sealing surface (6) is formed on a portion (13) of the nozzle needle (5) that has an enlarged outer diameter.

    8. The injection nozzle (1) according to claim 1, wherein the nozzle needle (5) opens outwards.

    9. The injection nozzle (1) according to claim 1, wherein the nozzle needle (5) opens inwards.

    10. A fuel injector having an injection nozzle (1) according to claim 1.

    11. The injection nozzle (1) according to claim 1, wherein the fluid is a liquid or gaseous fuel.

    12. The injection nozzle (1) according to claim 4, wherein the end portion (10) of the nozzle needle (5) is configured as a pin.

    Description

    BRIEF DESCRIPTION OF THE DRAWINGS

    [0021] Preferred embodiments of the invention are described in greater detail hereinafter with reference to the accompanying drawings. Shown are:

    [0022] FIG. 1 a schematic longitudinal section through a first injection nozzle according to the invention, and

    [0023] FIG. 2 a schematic longitudinal section through a second injection nozzle according to the invention.

    DETAILED DESCRIPTION

    [0024] FIG. 1 shows a first preferred embodiment of an injection nozzle 1 according to the invention. This comprises a nozzle body 2 in which a nozzle needle 5 is movably accommodated. The nozzle body 2 and the nozzle needle 5 delimit a flow path 4 for a fluid being injected. The flow path 4 passes over a sealing seat 3 formed by the nozzle body 2. The sealing seat 3 is conically shaped and oriented outward. In a portion 13 with an enlarged outer diameter, the nozzle needle 5 has a conically shaped sealing surface 6 that interacts with the sealing seat 3. The sealing surface 6 is oriented towards the nozzle body 2. Accordingly, the nozzle needle 5 opens outward (see arrow 15).

    [0025] To guide the nozzle needle 5, the nozzle body 2 has a guide 8 in an outer peripheral area. The guide 8 is surrounded by a guide element 7, which is fixedly connected to the nozzle needle 5. A central recess 9 is provided in the guide element 7 for this purpose, in which a pin-shaped end portion 10 of the nozzle needle 5 is accommodated. The guide element 7 delimits a flow chamber 11 downstream of the sealing seat 3, into which the fluid being injected flows when the nozzle needle 5 is open. In order to discharge the fluid from the flow chamber 11, the guide element 7 has openings 12 which are shaped in such a way that flow deflection is achieved at the same time.

    [0026] In the injection nozzle 1 shown in FIG. 1, the nozzle needle 5 is guided on the outside of the nozzle body 2, so that a close-fitting guide inside the nozzle body 2 is unnecessary. The flow cross-section in flow path 4 can thus be designed to the maximum. In particular, the formation of a choke point is avoided. Since the guide 8 formed on the outside of the nozzle body 2 is arranged outside the flow path 4, it can be optimized in terms of its guiding properties. Furthermore, the guide 8 can be arranged at the level of the sealing seat 3 so that the nozzle needle 5 is guided optimally.

    [0027] A further preferred embodiment of an injection nozzle 1 according to the invention is shown in FIG. 2. This differs from the embodiment of FIG. 1 in particular in that the nozzle needle 5 opens inward (see arrow 16). Consequently, the sealing seat 3 of the nozzle body 2 is oriented inward. The sealing surface 6 of the nozzle needle 5 interacting with the sealing seat 3 faces outward. Here, too, the nozzle needle 5 is connected to a guide element 7 which engages around a guide 8 formed on the outer periphery of the nozzle body. In the present case, the connection is made via a welded joint 14 between the nozzle needle 5 and the guide element 7 in the area of a pin-shaped end portion 10 of the nozzle needle 5 engaging in a recess 9 of the guide element 7.

    [0028] The advantages of the injection nozzle 1 according to the invention described above are also achieved with an inward-opening nozzle needle 5, so that the invention can be implemented optionally with an outward-opening and an inward-opening nozzle needle 5.