Fluid sprinkling – spraying – and diffusing – Fluid pressure responsive discharge modifier* or flow... – Fuel injector or burner
Reexamination Certificate
2000-07-19
2001-06-12
Moulis, Thomas N. (Department: 3747)
Fluid sprinkling, spraying, and diffusing
Fluid pressure responsive discharge modifier* or flow...
Fuel injector or burner
C239S585100
Reexamination Certificate
active
06244525
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to injectors for injecting fuel in the fluid state, in particular the liquid state, for the purpose injecting the fuel directly into a combustion chamber of a controlled ignition engine. It is particularly applicable to injecting gasoline, but it can also be adapted to other liquid fuels, such as alcohol-based fuels and liquefied petroleum gas.
Direct injection injectors are already known comprising an injector body containing a needle that is axially displaceable by electrical control means (often constituted by a coil) and terminated by a shutter member, often of hemispherical shape, that co-operates with a fuel flow seat. The needle is displaceable between a first axial position in which the shutter element bears against the seat and a position in which it is spaced apart therefrom.
The stresses imposed on the injector for direct injection are much higher than those for indirect injection into a manifold. It is necessary both to limit the penetration depth of the fuel jet, e.g. to avoid wetting the walls of the chamber, and to ensure mixing that is as intimate as possible between the air and the fuel for better combustion, and to do this even though the time available for fuel injection is very short.
To achieve this result, attempts have already been made to impart turbulent motion to the fuel. Document WO-A-96/36808 describes an injector performing that function. It has a swirling chamber for putting the fuel into rotation about the axis of the shutter element, which chamber is situated upstream from the seat so as to avoid the presence of a dead volume between the seat and the spray hole.
SUMMARY OF THE INVENTION
The present invention seeks in particular to provide a fuel injector that satisfies practical requirements better than previously known injectors, in particular in that it causes the fuel to be set into rotation by using means that are simple to implement while nevertheless being very effective.
To this end, the invention provides a fuel injector having a swirling chamber is defined by the upstream face of the seat, by a disk pressed against the seat and having slots opening out tangentially into a central opening surrounding the shutter element, and by a needle guide constituted in such a manner as to feed the outer ends of the slots.
The vortex effect achieved in this way has various consequences. The swirling of the vaporized fuel that passes through the diffusion hole that can be shut by the shutter element improves air-gasoline mixing and lengthens the path required before particles can reach the walls.
The disk is advantageously clamped between the guide, bearing against an inside shoulder of the body, and the seat which is fixed to the body in permanent manner, e.g. by welding. The path of the fuel towards the slots can be constituted by a radial jet provided between the guide and a bore of the body in which it is mounted. The needle which is then mounted as a sliding fit inside the guide enables the guide to be centered. The radial clearance required for a sliding fit is very small. It limits the passage for fluid, thereby improving the quality of the jet. The radial feed clearance can receive fuel via grooves formed in the upstream face of the guide, bearing against the internal shoulder.
In practice, the disk will have two to eight slots that can be rectilinear or angled in such a direction as to reinforce the rotation imparted by the slots opening out into the central opening.
The above characteristics and others will appear better on reading the following description of particular embodiments, given as non-limiting examples. The description refers to the accompanying drawings, in
REFERENCES:
patent: 4971254 (1990-11-01), Daly et al.
patent: 5570841 (1996-11-01), Pace et al.
patent: 5871157 (1999-02-01), Fukutomi et al.
patent: 5875972 (1999-03-01), Ren et al.
patent: 5931386 (1999-08-01), Jouillat
patent: 5979801 (1999-11-01), Munezane et al.
patent: 6024301 (2000-02-01), Hurley et al.
patent: 6065692 (2000-05-01), Brinn, Jr.
Estevenon Christine
Gallup David
Larson & Taylor PLC
Moulis Thomas N.
Sagem S.A.
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