Fuel system having sealed injection port
A nozzle assembly for a gaseous fuel injector of an engine is disclosed. The nozzle assembly may include a gaseous fuel injector having a nozzle with a tip end. The nozzle assembly may also include a blocking member having an inner contact surface configured to receive a periphery of the nozzle at the tip end, and an outer contact surface configured to engage an air intake port of a cylinder and create a hermetic seal between the gaseous fuel injector and the air intake port.
1. A fuel system for an engine having a cylinder with a plurality of radial air intake ports located circumferentially around a cylinder liner, the fuel system comprising:
a liquid fuel injector positioned inside a cylinder head associated with the cylinder and configured to inject liquid fuel axially into the cylinder;
a gaseous fuel injector positioned inside an air box of the engine and configured to inject gaseous fuel radially into the cylinder via one of the plurality of radial air intake ports and including a nozzle in direct communication with the one of the plurality of radial air intake ports; and
a blocking member including:
a generally rectangular body having an outer contact surface configured to engage a port wall associated with the one of the plurality of radial air intake ports; and
a centrally-located aperture formed in the body and configured to receive the nozzle of the gaseous fuel injector,
wherein one or more remaining radial air intake ports are fully open to allow air to pass between the air box and the cylinder after movement of a piston of the engine.
2. The fuel system of claim 1 , wherein the nozzle of the gaseous fuel injector includes a tip end, and only a portion of the tip end is exposed to an interior of the cylinder.
3. The fuel system of claim 1 , wherein the centrally located aperture is substantially circular.
4. The fuel system of claim 1 , wherein an annular surface of the centrally located aperture is welded to the periphery of the nozzle.
5. The fuel system of claim 1 , wherein an annular surface of the centrally located aperture is press-fit over the periphery of the nozzle.
6. The fuel system of claim 1 , wherein the outer contact surface of the blocking member is welded to the port wall associated with the one of the plurality of radial air intake ports.
7. The fuel system of claim 1 , wherein the outer contact surface of the blocking member is press-fit with the port wall associated with the one of the plurality of radial air intake ports.
8. The fuel system of claim 1 , wherein the generally rectangular body of the blocking member is made from cast-iron.
9. The fuel system of claim 1 , wherein at least one of the port wall associated with the one of the plurality of radial air intake ports and the nozzle of the gaseous fuel injector are also made from cast-iron.
10. The fuel system of claim 1 , wherein the centrally located aperture has a diameter that is about 0-10% smaller than a diameter of the nozzle.
11. The fuel system of claim 1 , wherein the rectangular body has a length and width that are about 0-10% larger than a length and width of the port wall associated with the one of the plurality of radial air intake ports.
12. The fuel system of claim 1 , further including at least one rounded corner formed in the outer contact surface of the generally rectangular body.
13. The fuel system of claim 1 , further including at least one bevel located on a face of the rectangular body and configured to be oriented towards an air box of the engine.
14. The fuel system of claim 1 , wherein the nozzle of the gaseous fuel injector includes a tip end, and the centrally located aperture of the blocking member is only configured to receive the tip end of the nozzle.
15. The fuel system of claim 1 , wherein the blocking member includes:
an inner face oriented towards an interior of the cylinder;
an outer face opposite the inner face and oriented towards an air box associated with the cylinder;
a top surface perpendicular to the inner and outer faces;
a bottom surface opposite and substantially parallel to the top surface; and
two opposing side surfaces that are substantially parallel with each other and perpendicular to the top and bottom surfaces and to the inner and outer faces.