Internal-combustion engines – Charge forming device – With fuel pump
Reexamination Certificate
1999-10-04
2001-07-03
Miller, Carl S. (Department: 3747)
Internal-combustion engines
Charge forming device
With fuel pump
C123S541000
Reexamination Certificate
active
06253738
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the improvements of a fuel feeder suitable to deliver fuel stored in a fuel tank of an automotive vehicle to an internal combustion engine.
2. Description of the Prior Art
Most cars commonly use an in-tank fuel feeder in which an in-tank fuel pump is located in the fuel tank to deliver the fuel discharged and pressurized from the pump to each individual fuel injector mounted on the engine. A pressure regulator is also connected to the discharge side of the fuel pump to maintain the correct fuel pressure to the injector. The in-tank fuel feeder generally includes a cylindrical fuel filter case which defining two spaces, namely a fuel-filter accommodating space between its inner and outer peripheries and a fuel pump accommodating space surrounded by the inner peripheral wall surface, a fuel pump provided in the pump accommodating space and discharging and delivering the fuel from the fuel tank to the fuel-filter accommodating space, a filter element provided in the fuel-filter accommodating space to remove dirt and other contaminants from the fuel discharged from the pump, and a pressure regulator installed at the bottom of the fuel filter case to regulate the fuel pressure in the fuel-filter accommodating space and having a fuel return port to return some of the fuel to the tank if the fuel pressure goes too high. One such in-tank fuel feeder has been disclosed in an international publication No. WO 96/23967. In the previously-described conventional in-tank fuel feeder, the fuel pump is installed in the pump accommodating space surrounded by the inner periphery of the fuel filter case, the filter element is installed in the fuel-filter accommodating space defined between the inner and outer peripheries of the filter case, and also the pressure regulator is arranged at the bottom of the filter case so that the return port opens to the downward direction. The upper end of the filter case is installed on the upper face of the fuel tank by means of a mounting bracket, whereas the lower end of the filter case vertically extends nearby the bottom of the fuel tank so that the lower end remains soaked in the fuel stored in the fuel tank. On the other hand, the upper fuel outlet port (fuel feed port) of the filter case is connected via a fuel feed line (a fuel feed pipe) to each individual fuel injector of the engine. As discussed above, in the conventional fuel feeder, the filter case extends vertically in a manner so as to hang down about the fuel-tank bottom wall. When the pump is working, the fuel in the tank is delivered from the fuel outlet port located at the upper end of the filter case via the fuel feed line to the injector, while fuel in excess of requirements passes out through the return port of the pressure regulator located at the bottom of the filter case and thence back to the tank. The arrangement of the return port of the pressure regulator of the conventional fuel feeder is insufficient from the viewpoint of noises and vibrations.
SUMMARY OF THE INVENTION
That is to say, in case that the return port of the pressure regulator is arranged to open to the downward direction near at the bottom of the fuel tank, there is an increased tendency for the superfluous fuel flowing out of the return port to be brought into collision-contact with the bottom wall of the tank. Additionally, the fuel pump is designed so that the pump can always discharge or deliver more fuel than the fuel injectors of the engine need. During engine operation, fuel in excess of requirements continually returns through the pressure regulator to the tank and thus continues to impinge against the bottom wall of the tank. Owing to the impingement of the superfluous fuel flow against the bottom wall of the tank, undesired noises and vibrations take place during the engine operation. This reduces comfortability of the automotive vehicle and results in degradation in quality of the fuel feeder.
Accordingly, it is an object of the invention to provide a fuel feeder for automotive vehicles which avoids the aforementioned disadvantages of the prior art.
It is another object of the invention to provide an in-tank fuel feeder which is capable of reducing noises and vibrations occurring owing to superfluous fuel flow returned through a pressure regulator to a fuel tank to the minimum when an in-tank fuel pump is working, thus enhancing both comfortability and quality.
In order to accomplish the aforementioned and other objects of the present invention, a fuel feeder comprises a filter case including an inner tubular portion and an outer tubular portion, defining a fuel-filter accommodating space between an outer peripheral wall of the inner tubular portion and an inner peripheral wall of the outer tubular portion, and defining a fuel pump accommodating space in an inner peripheral wall of the inner tubular portion, an in-tank fuel pump adapted to be located in a fuel tank by accommodating the in-tank fuel pump in the pump accommodating space of the filter case, and discharging fuel in the fuel tank into the fuel-filter accommodating space, a filter element accommodated in the fuel-filter accommodating space to remove dirt and other contaminants from the fuel discharged from the in-tank fuel pump and passing through the filter element, a pressure regulator installed on the filter case and having a fuel return port to return superfluous fuel to the fuel tank if a fuel pressure in the fuel-filter accommodating space exceeds a predetermined pressure level, the pressure regulator located at an upper side of the filter case, and a fuel return pipe connected at one end to the fuel return port of the pressure regulator and having a conduit portion extending downwards from the one end along the outer peripheral wall of the outer tubular portion of the filter case.
According to another aspect of the invention, a fuel feeder comprises a filter case including an inner tubular portion and an outer tubular portion, defining a fuel-filter accommodating space between an outer peripheral wall of the inner tubular portion and an inner peripheral wall of the outer tubular portion, and defining a fuel pump accommodating space in an inner peripheral wall of the inner tubular portion, an in-tank fuel pump adapted to be located in a fuel tank by accommodating the in-tank fuel pump in the pump accommodating space of the filter case, and discharging fuel in the fuel tank into the fuel-filter accommodating space, a filter element accommodated in the fuel-filter accommodating space to remove dirt and other contaminants from the fuel discharged from the in-tank fuel pump and passing through the filter element, a pressure regulator installed on the filter case and having a fuel return port to return superfluous fuel to the fuel tank if a fuel pressure in the fuel-filter accommodating space exceeds a predetermined pressure level, the pressure regulator located at an upper side of the filter case, and a fuel return pipe connected to the fuel return port of the pressure regulator for returning the superfluous fuel to the fuel tank, the fuel return pipe comprising a fitted portion which is fitted onto a downstream end of the fuel return port of the pressure regulator, a conduit portion extending downwards from the fitted portion along the outer peripheral wall of the outer tubular portion of the filter case, a return-fuel outlet formed in a side of the conduit portion facing the outer peripheral wall of the outer tubular portion of the filter case and located at a position upwardly spaced apart from a bottom portion of the fuel-tank, and a curved wall surface portion formed in a lowermost end of the conduit portion so that the curved wall surface is curved in a direction of the outer peripheral wall of the outer tubular portion of the filter case and formed into a substantially concave, spherical surface, whereby the curved wall surface cooperates with the return-fuel outlet so that superfluous fuel flow is directed toward the outer peripheral wall of the outer
Hashimoto Takashi
Takahashi Koji
Foley & Lardner
Miller Carl S.
Unisia Secs Corporation
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