Field of the invention
[0001] This invention relates to a fuel inlet valve for an engine, and more specifically to a fuel inlet valve that is operated as a fuel injector in an engine.
Background of the invention
[0002] US 4448166 A describes a unit injector that is disposed on a cylinder head in an oblique state and rocker arms for actuating intake and exhaust valves, respectively, are disposed on both sides of the unit injector. Another rocker arm for actuating the unit injector is disposed between these two rocker arms. Support beds for supporting a rocker arm shaft that supports both rocker arms for actuating the intake and exhaust valves and another rocker arm shaft that supports the rocker arm for actuating the unit injector are formed as a unitary structure. One cam shaft for operating the rocker arms for actuating the intake and exhaust valves and the rocker arm for actuating the unit injector is disposed at a low position on the side of the unit injector as close as possible to the axis of a piston. A governor for adjusting the fuel injection quantity of the unit injector is fitted to one end of the cam shaft, in which the arrangement is such that the governor is operatively associated with a control rod disposed parallel to the crank shaft, which rod is operable in association with each unit injector to adjust the fuel injection quantity.
Brief description of the accompanying drawing
[0003] Figure 1 illustrates a fuel inlet valve for an engine.
Detailed description of the embodiments
[0004] Figure 1 illustrates a fuel inlet valve 10 operated as a fuel injector in an engine. The fuel inlet valve 10 comprises a top portion 12 adapted to be actuated by a cam 14, a bottom portion 16, and a cylindrical portion 18 extending between the top portion 12 and the bottom portion 16. A radial slot 20 is defined in the cylindrical portion 18. A

longitudinal slot 22 is orthogonally defined with respect to the radial slot 20 in the cylindrical portion 18 and in flow communication with the radial slot 20, the longitudinal slot 22 defined along a longitudinal axis of the cylindrical portion 18. At least one orifice hole 24 is orthogonally defined with respect to the longitudinal slot 22 and in flow communication with the longitudinal slot 22, the at least one orifice hole 24 extending from the longitudinal slot 22 to a circumference of the cylindrical portion 18, the at least one orifice hole 24 adapted to deliver pressurized fuel that flows through the longitudinal slot 22 out of the fuel inlet valve 10.
[0005] The fuel inlet valve 10 comprises a top portion 12 that may be actuated by a cam 14. More specifically, the top portion 12 is positioned below the cam 14. When the cam 14 rotates, the top portion 12 is actuated due to the surface of the cam 14 coming in contact with the top portion 12 of the fuel inlet valve 10. More specifically, the top portion 12 of the fuel inlet valve 10 is pushed towards the engine cylinder due to the surface of the cam 14 rolling over the top portion 12 of the fuel inlet valve 10 when the cam 14 rotates in the clockwise direction. The fuel inlet valve 10 comprises a bottom portion 16 that is conically shaped and positioned against a cylinder head in its equilibrium position. Therefore, when the bottom portion 16 of the fuel inlet valve 10 is pushed in the downward direction, the fuel is injected into the engine cylinder that is positioned below the cylinder head 17.
[0006] A cylindrical portion 18 extends between the top portion 12 and the bottom portion 16. The cylindrical portion 18 comprises a solid body and includes a radial slot 20 defined therein. The radial slot 20 extends from an outer circumference of the cylindrical portion 18 to a portion that is within the cylindrical portion 18. More specifically, the radial slot 20 is milled from the outer circumference of the cylindrical portion 18 to the portion that is within the cylindrical portion 18. The radial slot 20 is adapted to channel fuel from a high pressure fuel pump to the portion that is within

the cylindrical portion 18 via the outer circumference of the cylindrical portion 18. A longitudinal slot 22 is orthogonally defined with respect to the radial slot 20 in the cylindrical portion 18. The longitudinal slot 22 is in flow communication with the radial slot 20 and is adapted to receive the fuel that is channeled through the radial slot 20. In the exemplary embodiment, the longitudinal slot 22 is defined along the longitudinal axis of the cylindrical portion 18. At least one orifice hole 24 is defined with respect to the longitudinal slot 22. More specifically, the at least one orifice hole 24 is orthogonally defined with respect to the longitudinal slot 22 and in flow communication with the longitudinal slot 22, and extends from the longitudinal slot 22 to a circumference of the cylindrical portion 18. The at least one orifice hole 24 is adapted to deliver pressurized fuel that flows through the longitudinal slot 22 out of the fuel inlet valve 10 past the cylinder head 17 and into a cylinder of the engine.
[0007] The fuel inlet valve 10 further comprises an L-shaped member 26 that is positioned within the radial slot 20 that is defined in the cylindrical portion 18 and the longitudinal slot 22 that is defined along the longitudinal axis of the cylindrical portion 18 of the fuel inlet vale 10. The L-shaped member 26 that is positioned within the radial slot 20 comprises an outer diameter, an inner diameter, and a bore extending along an axis of the inner diameter. The first end of the L-shaped member 26 is in flow communication with a high pressure fuel pump and receives fuel that is supplied from the high pressure fuel pump. The opposite second end of the L-shaped member 26 is positioned within the longitudinal slot 22 and is secured against an end portion of the longitudinal slot 22, thereby closing the bore of the L-shaped member 26. Therefore, the fuel that flows through the L-shaped member 26 from the first end of the L-shaped member 26 is trapped inside the L-shaped member 26 because the opposite second end of the L-shaped member 26 is secured against an end portion of the longitudinal slot 22 that prevents the fuel from flowing out of the L-shaped member 26. The L-shaped member 26 is held in this position by securing the first end of the L-shaped member

to a housing (not shown) of the engine. Therefore, the L-shaped member 26 cannot translate within the longitudinal slot 22 of the cylindrical portion 18 as it is secured to the housing of the engine. The cylindrical portion 18 of the fuel inlet valve 10 is adapted to translate due to the rotation of the cam 14. More specifically, due to the translation of the cylindrical portion 18, the longitudinal slot 22 translates, thereby releasing pressurized fuel from the L-shaped member 26 to the at least one orifice hole 24 for fuel delivery out of the fuel inlet valve 10 as will be explained in further detail below. In the exemplary embodiment, the at least one orifice hole 24 is defined proximate to the bottom portion of the fuel inlet valve 10 and abuts the bottom portion 16 of the fuel inlet valve 10.
[0008] A working of the fuel inlet valve 10 is described as an example. The L-shaped member 26 that is positioned within the cylindrical portion 18 is prevented from releasing fuel because the opposite second end of the L-shaped member 26 is positioned against an end portion of the longitudinal slot 22 that prevents the fuel from flowing out of the L-shaped member 26. When the cam 14 rotates, the fuel inlet valve 10 is moved away from the cylinder head as the force applied by the cam 14 on the top portion 12 of the fuel inlet valve 10 causes the actuation of the fuel inlet valve 10. The actuation of the fuel inlet valve 10 causes the translation of the longitudinal slot 22 that is defined in the cylindrical portion 18 away from the L-shaped member 26. This causes the opposite second end of the L-shaped member 26 to come in contact with the at least one orifice hole 24. When the opposite second end of the L-shaped member 26 comes in contact with the at least one orifice hole 24, the fuel flows out of the opposite second end of the L-shaped member 26 and out of the cylindrical portion 18 of the fuel inlet valve 10 and into the engine cylinder by ejecting fuel through the opening 24. Fuel injection will happen when the peak profile of the cam 14 is in contact with the top portion 12. The fuel inlet valve 10 is restored to its original position against the cylinder head of the engine when the peak profile of the cam 14 is not in

contact with top portion 12. Therein, the L-shaped portion 26 that is positioned within the cylindrical portion 18 is prevented from releasing fuel because the opposite second end of the L-shaped member 26 is positioned against the end portion of the longitudinal slot 22 that prevents the fuel from flowing out of the L-shaped member 26.
[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.

We Claim
1. A fuel inlet valve (10) for operating as a fuel injector in an engine, said fuel
inlet valve (10) comprising:
a top portion (12) adapted to be actuated by a cam (14), a bottom portion (16),
and a cylindrical portion (18) extending between the top portion (12) and the
bottom portion (16);
a radial slot (20) defined in the cylindrical portion (18);
a longitudinal slot (22) orthogonally defined with respect to the radial slot (20)
in the cylindrical portion (18) and in flow communication with the radial slot
(20), the longitudinal slot (22) defined along a longitudinal axis of the
cylindrical portion (18); and
at least one orifice hole (24) orthogonally defined with respect to the
longitudinal slot (22) and in flow communication with the longitudinal slot
(22), the at least one orifice hole (24) extending from the longitudinal slot (22)
to a circumference of the cylindrical portion (18), the at least one orifice hole
(24) adapted to deliver pressurized fuel that flows through the longitudinal slot
(22) out of the fuel inlet valve (10).
2. The fuel inlet valve (10) for operating as a fuel injector in an engine further
comprising an L-shaped member (26) positioned within the radial slot (20)
defined in the cylindrical portion (18) and the longitudinal slot (22) that is
defined along the longitudinal axis of the cylindrical portion (18), the L-shaped
member (26) adapted to deliver pressurized fuel to the at least one orifice hole
(24) for fuel delivery out of the fuel inlet valve (10).

3. The fuel inlet valve (10) for operating as a fuel injector in an engine wherein the at least one orifice hole (24) is defined proximate to the bottom portion of the fuel inlet valve (10).