Patent Application
20090056817
The present invention relates generally to pressure regulators, and more particularly to fuel pressure regulators for vehicles.
Fuel injection systems for automotive engines commonly include electromagnetic fuel injectors that deliver fuel from a fuel rail to the engine inlet manifold adjacent the engine combustion chamber inlet ports. Such fuel injection systems ordinarily include a fuel pressure regulator to control the pressure of the fuel in the rail. Fuel pressure regulators may also be used in carbureted systems.
With particular respect to fuel injected systems, the pressure in the fuel rail is usually controlled to maintain a constant pressure difference across the injector (i.e. from the pressure in the fuel rail to the pressure in the manifold). The fuel pressure regulator, which may be connected directly to the fuel rail or incorporated in a pump module at the outlet of the fuel pump, recirculates excess fuel back to the fuel tank as necessary to maintain a constant pressure at the inlet to the injectors.
As understood herein, it is preferable to maintain pressure within a relatively small pressure range, to optimize injector performance. As way to measure how close a regulator maintains pressure to a desired pressure is “gain”, with many automotive applications requiring a pressure regulator “gain” of no more than one-half kiloPascal per gram per second (≦0.50 kPa/g/s). As further understood herein, it is preferable to provide a regulator for this purpose which is inexpensive, and further which does not result in excessive pressure pulsation and excessive noise due to, e.g., valve chatter or cavitation.
In one embodiment, a fuel pressure regulator includes a housing defining a fuel inlet and a fuel outlet, and a ball in the housing is movable between a closed configuration, wherein fluid communication between the inlet and outlet is blocked, and an open configuration, wherein fluid communication between the inlet and outlet is not blocked. Fuel pressure urges the ball toward the open configuration. A spring in the housing is engaged with the ball to urge the ball toward the closed configuration. Also, a ball holder is engaged with the ball and spring and is oriented to receive fluid pressure from the inlet when the ball is moved away from the closed configuration. Fluid pressure from the inlet acts directly against the ball holder as well as against the ball to assist moving the ball toward the open configuration.
The non-limiting fuel pressure regulator has a gain of no more than thirty five hundredths kiloPascals per gram per second (0.35 kPa/g/s). In other implementations particularly not incorporating a spring plate, the gain may be higher.
In some embodiments the inlet defines a valve seat, and the ball is urged against the valve seat in the closed configuration. The ball can be press-fit into the ball holder such that rotational motion and lateral motion of the ball during ball movement is substantially prevented, i.e., the ball substantially does not move relative to the ball holder.
As set forth further below, in non-limiting embodiments the ball holder includes an assist wing extending substantially radially away from the ball and oriented substantially laterally to the inlet. Also, the ball holder can include a spring engagement wing oriented substantially laterally to the inlet and engaging the spring. The ball receptacle defines a longitudinal axis parallel to the direction of ball motion when the ball moves between the closed and open configurations, and the assist wing may be established by a disk-shaped flange extending laterally away from ball receptacle and circumscribing the receptacle.
In another aspect, a fuel pressure regulator for supplying fuel at a substantially constant pressure has a housing with a fuel inlet and a fuel outlet. The housing defines a seating surface. A valve element is movably disposed within the housing and is movable between an open position permitting fuel flow through the housing, and a closed position preventing fuel flow through the housing. The valve element includes a roundular seating member engageable with the seating surface in the closed position and a guide member receiving fluid pressure when the roundular member is distanced from the seating surface to aid in urging the roundular member toward the open position.
In yet another aspect, a fuel system has a fuel pump, one or more fuel injectors receiving fuel from the pump, and a fuel pressure regulator communicating with the pump to regulate pressure of fluid provided to the injector. The fuel pressure regulator includes means for closing the fuel pressure regulator. The means for closing is urged by fluid pressure to an open position. The fuel pressure regulator also has means for urging the means for closing toward a closed configuration. Means are provided that are operable only when the means for closing is not in the closed position for receiving fluid pressure and by dint of the fluid pressure to assist in urging the means for closing toward the open position.
The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which:
Referring initially to
Details of a non-limiting implementation of the fuel pressure regulator 20 are shown in
In specific non-limiting implementations the ball 32 is press-fit into a cylindrical ball receptacle of the ball holder 40. In the embodiment shown the cylindrical ball receptacle may include an upper, radially wider segment 46 and a lower, radially narrower segment 48 (
It may now be appreciated in cross-reference to
While the particular FUEL PRESSURE REGULATOR FOR VEHICLE is herein shown and described in detail, it is to be understood that the subject matter which is encompassed by the present invention is limited only by the claims.
