Description: Complete Specification:

The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.
Field of the invention
[0001] This invention relates to a fuel injector, and more specifically to a knife edge that is defined on a top surface of the nozzle body of the fuel injector.

Background of the invention
[0002] US 11174827 BA describes a fuel injector with an internal radial seal with a thin wall counter bore. The fuel injector body includes an at least partially annular configuration defining a longitudinal axis, a circumferential direction, and a radial direction. A first counterbore and a first cavity extend from the first end toward the second end, and an external interface portion includes a sealing surface disposed axially between the first end and a shoulder. The first cavity defines a bottom surface and a peripheral surface defining a first cavity diameter, and the sealing surface defines a sealing surface diameter. A ratio of the sealing surface diameter to the first cavity diameter ranges from 0.3 to 4.4.

Brief description of the accompanying drawing
[0003] Figure 1 illustrates a knife edge that is defined on a top surface of a nozzle body of a fuel injector in one embodiment of the invention.

Detailed description of the embodiments
[0004] Figure 1 illustrates a fuel injector 10. The fuel injector 10 comprises an injector body, and a nozzle body 12 positioned against the injector body such that a fuel inlet flow path of the injector body is flush against a fuel inlet flow path 14 of the nozzle body 12 to facilitate a flow of fuel from the fuel inlet flow path of the injector body to the fuel inlet flow path 14 of the nozzle body 12. A knife edge 16 is defined circumferentially around a periphery of the nozzle body 12. The knife edge 16 that is defined circumferentially around the periphery of the nozzle body 12 adapted to abut circumferentially against the injector body to facilitate preventing fuel that flows through a clearance 18 that is defined between the fuel inlet flow path of the injector body and the fuel inlet flow path 14 of the nozzle body 12 from flowing past the knife edge 16 towards the periphery 20 of the nozzle body 12.

[0005] Figure 1 illustrates a knife edge 16 that is defined on a top surface of a nozzle body 12 of a fuel injector 10 in one embodiment of the invention. The fuel injector 10 comprises an injector body (not shown), and a nozzle body 12 that is positioned against the injector body such that a fuel inlet flow path (not shown) that is defined in the injector body is in alignment with a fuel inlet flow path 14 that is defined in the nozzle body 12. The alignment of the fuel inlet flow path that is defined in the injector body with the fuel inlet flow path 14 that is defined in the nozzle body 12 facilitates a flow of fuel from the fuel inlet flow path of the injector body to the fuel inlet flow path 14 of the nozzle body 12. In an exemplary embodiment, during an assembly of the fuel inlet flow path that is defined in the injector body with the fuel inlet flow path 14 that is defined in the nozzle body 12, a small clearance 18 exists between the fuel inlet flow path that is defined in the injector body and the fuel inlet flow path 14 that is defined in the nozzle body 12. The clearance 18 that is defined between the fuel inlet flow path that is defined in the injector body and the fuel inlet flow path 14 that is defined in the nozzle body 12 facilitates for the flow of fuel that flows from the fuel inlet flow path that is defined in the injector body to the fuel inlet flow path 14 that is defined in the nozzle body 12. From the clearance 18 that is defined between the fuel inlet flow path that is defined in the injector body and the fuel inlet flow path 14 that is defined in the nozzle body 12, the fuel flows to the outer periphery 20 of the nozzle body 12.

[0006] In an exemplary embodiment, a knife edge 16 is defined circumferentially around a periphery of the nozzle body 12. More specifically, the knife edge 16 that is defined circumferentially around the periphery of the nozzle body 12 is adapted to abut circumferentially against the injector body to facilitate preventing fuel that flows through the clearance 18 that is defined between the fuel inlet flow path of the injector body and the fuel inlet flow path 14 of the nozzle body 12 from flowing past the knife edge 16 towards the periphery 20 of the nozzle body 12. Therefore, the knife edge 16 that is defined circumferentially around the periphery of the nozzle body 12 that is adapted to abut circumferentially against the injector body facilitates creating a sealing arrangement between the nozzle body 12 and the injector body respectively. More specifically, the abutment of the knife edge 16 that is defined circumferentially around the periphery of the nozzle body 12 against a periphery of the injector body facilitates preventing fuel that flows through the clearance 18 that is defined between the fuel inlet flow path of the injector body and the fuel inlet flow path 14 of the nozzle body 12 from crossing the knife edge 16 and reaching the periphery 20 of the nozzle body 12.

[0007] In an exemplary embodiment, the knife edge 16 comprises a base portion 22 and a conically shaped portion 24 extending from the base portion 22 towards the injector body. More specifically, the conically shaped portion 24 extending from the base portion 22 of the knife edge 16 towards the injector body is adapted to abut against the injector body such that no clearance exists between the tip of the conically shaped portion 24 of the nozzle body 12 and the injector body. Therefore, the fuel that flows through the clearance 18 that is defined between the fuel inlet flow path of the injector body and the fuel inlet flow path 14 of the nozzle body 12 is retained therein and is prevented from flowing outwardly therefrom. In an exemplary embodiment, the knife edge 16 that is defined circumferentially around the circumference of the nozzle body 12 is integrally formed with the nozzle body 12 during casting of the nozzle body 12. In an alternate exemplary embodiment, the knife edge 16 that is defined circumferentially around the circumference of the nozzle body 12 is secured to the nozzle body 12 by means of a mechanical fastener that is known in the art.

[0008] In an exemplary embodiment, the knife edge 16 that is defined circumferentially around a circumference of the nozzle body 12 is formed between the periphery of the nozzle body 12 and the fuel inlet flow path 14 of the nozzle body 12. Therefore, the knife edge 16 that is formed between the periphery 20 of the nozzle body 12 and the fuel inlet flow path 14 of the nozzle body 12 facilitates preventing fuel that flows through a clearance defined between the fuel inlet flow path of the injector body and the fuel inlet flow path 14 of the nozzle body 12 from flowing past the knife edge 16 towards the periphery of the nozzle body 12. Therefore, the knife edge 16 secures the fuel within the clearance 18 that is defined between the fuel inlet flow path of the injector body and the fuel inlet flow path 14 of the nozzle body 12 such that the fuel is bounded between the clearance 18 that is defined between the fuel inlet flow path of the injector body, the fuel inlet flow path 14 of the nozzle body 12, and the knife edge 16 respectively. Moreover, the knife edge 16 that is defined circumferentially around the circumference of the nozzle body 12 is spaced apart from the periphery of the nozzle body 12 by a user defined displacement. Therefore, there exists a gap between the knife edge 16 that is defined circumferentially around the circumference of the nozzle body 12 and the periphery 20 of the nozzle body 12 of the fuel injector 10.

[0009] It must be understood that the embodiments explained above are only illustrative and do not limit the scope of the disclosure. Many modifications in the embodiments with regard to dimensions of various components are envisaged and form a part of this invention. The scope of the invention is only limited by the scope of the claims. , Claims: We Claim

1. A fuel injector (10), said fuel injector (10) comprising:
an injector body;
a nozzle body (12) positioned against the injector body such that a fuel inlet flow path of the injector body is flush against a fuel inlet flow path (14) of the nozzle body (12) to facilitate a flow of fuel from the fuel inlet flow path of the injector body to the fuel inlet flow path (14) of the nozzle body (12); characterized in that
a knife edge (16) defined circumferentially around a periphery of the nozzle body (12), the knife edge (16) that is defined circumferentially around the periphery of the nozzle body (12) adapted to abut circumferentially against the injector body to facilitate preventing fuel that flows through a clearance (18) that is defined between the fuel inlet flow path of the injector body and the fuel inlet flow path (14) of the nozzle body (12) from flowing past the knife edge (16) towards the periphery (20) of the nozzle body (12).

2. The fuel injector (10) in accordance with Claim 1, wherein the knife edge (16) comprises a base portion (22) and a conically shaped portion (24) extending from the base portion (22) towards the injector body such that an end of the conically shaped portion (24) of the knife edge (16) is adapted to abut against the injector body such that no clearance exists between the nozzle body (12) and the injector body.

3. The fuel injector (10) in accordance with Claim 1, wherein the knife edge (16) that is defined circumferentially around the circumference of the nozzle body (12) is integrally formed with the nozzle body (12) during casting of the nozzle body (12).

4. The fuel injector (10) in accordance with Claim 1, wherein the knife edge (16) that is defined circumferentially around the circumference of the nozzle body (12) is secured to the nozzle body (12) by means of a mechanical fastener.

5. The fuel injector (10) in accordance with Claim 1, wherein the knife edge (16) that is defined circumferentially around a circumference of the nozzle body (12) is formed between the periphery of the nozzle body (12) and the fuel inlet flow path (14) of the nozzle body (12) to facilitate preventing fuel that flows through a clearance defined between the fuel inlet flow path of the injector body and the fuel inlet flow path (14) of the nozzle body (12) from flowing past the knife edge (16) towards the periphery (20) of the nozzle body (12).

6. The fuel injector (10) in accordance with Claim 5, wherein the knife edge (16) that is defined circumferentially around a circumference of the nozzle body (12) is spaced apart from the periphery of the nozzle body (12) by a user defined displacement.