Fuel pump module with replaceable filter unit

A fuel supply system includes a fuel pump having an inlet configured to pick up fuel and an outlet configured to discharge fuel. A pressure vessel is in fluid communication with the outlet of the fuel pump such that fuel is directed from the fuel pump into the pressure vessel, the pressure vessel having an outlet port. A pressure regulation valve subassembly is detachably coupled with the outlet port via a male-female interface that positively locks against axial separation upon axial coupling in a first orientation and relative rotation of less than 360 degrees to a second orientation. A reservoir defines an internal space at least partially receiving the fuel pump, the pressure vessel, and the pressure regulation valve subassembly. The reservoir includes an interior wall that obstructs rotation of the pressure regulation valve subassembly from the second orientation to the first orientation.

BACKGROUND

The present invention relates to fuel supply systems, such as those provided within a motor vehicle. Although a vehicular fuel supply system will include a variety of components for managing the supply of fuel from a fuel tank to an internal combustion engine, a portion of the fuel supply system commonly referred to as the fuel pump module resides within the fuel tank and typically includes a pump unit and a filter unit. The pump unit pumps fuel from the tank through the filter unit and out to the engine. The pressure at the outlet of the fuel pump module can be regulated by a valve. In a typical system, the filter unit includes at least one permanent hose connection to a mounting flange such that routine replacement of the filter unit is not feasible. The pressure regulating valve of the fuel pump module may also be permanently locked in place with respect to the filter unit upon original assembly of the filter unit, for example, as the pressure regulating valve is captured between upper and lower portions of a housing that are welded together at the time of manufacture.

SUMMARY

In one aspect, the invention provides a fuel supply system including a fuel pump having an inlet configured to pick up fuel and an outlet configured to discharge fuel. A pressure vessel is in fluid communication with the outlet of the fuel pump such that fuel is directed from the fuel pump into the pressure vessel, the pressure vessel having an outlet port. A pressure regulation valve subassembly is detachably coupled with the outlet port via a male-female interface that positively locks against axial separation upon axial coupling in a first orientation and relative rotation of less than 360 degrees to a second orientation. A reservoir defines an internal space at least partially receiving the fuel pump, the pressure vessel, and the pressure regulation valve subassembly. The reservoir includes an interior wall that obstructs rotation of the pressure regulation valve subassembly from the second orientation to the first orientation.

In another aspect, the invention provides a fuel pump module for a motor vehicle including an engine. The fuel pump module includes a fuel pump, a tank-mounting flange having a fitting for attachment with a fuel supply line to the engine, and a filter unit having no direct fluid connection to the tank-mounting flange. The filter unit includes a housing defining a pressure vessel coupled to an outlet of the fuel pump, a cover defining an upper portion of the pressure vessel and forming an outlet port of the pressure vessel, and a filter positioned within the pressure vessel. A pressure regulation valve subassembly is removably coupled to the outlet port via an interface that allows free axial coupling and decoupling in a first rotational orientation of the pressure regulation valve subassembly relative to the outlet port and provides positive axial locking in a second rotational orientation of the pressure regulation valve subassembly relative to the outlet port. The filter unit is non-destructively removable from the pressure regulation valve subassembly to facilitate exchange of the filter unit within the fuel pump module.

DETAILED DESCRIPTION

As shown inFIG. 1, a fuel supply module or fuel pump module20is provided as part of a fuel supply system for a motor vehicle. The fuel pump module20is positioned within a fuel tank22of the motor vehicle for supplying fuel to a fuel burning device, such as an internal combustion engine23. The pump module20includes a fuel pump, or pump unit24operable to pressurize liquid fuel when energized for movement though the system. The pump unit24is positioned in a receptacle30of a housing32. The pump unit24can be insertable into the receptacle30in the axial or vertical direction and can be retained with a clip36or other device. In other constructions, the pump unit24may be positioned relative to the housing32in other ways. Although positionally retained in relation to the housing32, the pump unit24also includes a case or housing of its own. The pump unit24defines an inlet24A (e.g., at a bottom end) and an outlet24B (e.g., at an upper end) between which the pump unit24includes a mechanism for pressurizing fuel. Although not shown, an inlet filter or strainer may be provided at the inlet24A. A reservoir34defining a cup-like fuel chamber at least partially receives the pump unit24and the housing32such that the pump unit24is submerged in a relatively consistent level of fuel independent of the prevailing level or potential sloshing within the tank22. A fuel level sensor25supported by the fuel pump module20is operable to sense a fuel level outside the reservoir34within the tank22. The fuel level sensor25can be a float type as shown or another type of level sensor.FIG. 2shows components of the fuel pump module20in an exploded assembly view.

A tank-mounting flange26is provided at a top end of the fuel pump module20such that the housing32and the pump module20are suspended below by a plurality of guide rods28. The flange26resides in an opening of the fuel tank22and has an exterior surface provided with hydraulic and electrical connections for communication between the fuel pump module20and the engine23, the environment, an electrical power source (e.g., battery), and an electronic controller. The flange26can include fuel send and return ports26A,26B, a vent port26C, and an electronic plug connection26D.

The housing32defines a pressure vessel40(FIG. 6) receiving the fuel pressurized by the pump unit24. The pressure vessel40can constitute a majority portion of the housing32. The pressure vessel40can be utilized for defining a volume directly surrounding a filter42. Thus, the pressure vessel40can be part of a filter unit44positioned alongside and functionally downstream of the pump unit24. Fuel is pumped via the pump unit24through a check valve (not shown) to the pressure vessel40and out an outlet port52toward the engine23via the flange26.FIG. 6illustrates a portion of an intermediate channel46in the housing32which directs fuel from the outlet24B of the pump unit24into the pressure vessel40. An auxiliary outlet from the housing32between the pump outlet24B and the pressure vessel40drives a jet pump54which continually operates to pump fuel from the tank22into the reservoir34. The illustrated outlet port52is formed integrally as a single piece with a cover56located at an upper end of the pressure vessel40. The cover56may be permanently affixed to the housing32to define the pressure vessel40(e.g., by hot plate welding or other type of non-serviceable connection which is not removable without destructive means).

The cover56includes a plurality of mounting tabs56A at a periphery thereof. Each of the mounting tabs56A extends outwardly away from the pressure vessel40and physically interferes with the reservoir34in top view (FIG. 3). An aperture56B is provided through each of the mounting tabs56A, the apertures56B receiving corresponding ones of the guide rods28. Just below its top edge, the reservoir34is provided with corresponding openings58for receiving the mounting tabs56A. The reservoir34can be flexed and elastically deformed to allow the mounting tabs56A to be positioned into the corresponding openings58at the time of assembly. Once assembled, the guide rods28prevent movement that may otherwise lead to disassembly of the housing32, and thus the filter unit44and the pump unit24, from the reservoir34, and the position of the fuel pump module20within the tank22is maintained during normal operation.

A pressure regulation valve subassembly60includes an opening62coupled to the outlet port52, which forms the outlet of the pressure vessel40and of the filter unit44as a whole. The opening62forms an inlet port of the pressure regulation valve subassembly60as shown. The connection between the pressure regulation valve subassembly60and the outlet port52is discussed in further detail below. The pressure regulation valve subassembly60has a tubular body64extended at a 90-degree angle from the opening62, the body64extending generally downward away from the flange26toward a bottom wall of the reservoir34to terminate at an end cover66at its lower end. A pressure regulating valve68is positioned within a chamber of the pressure regulation valve subassembly60, for example, at a bottom of the body64, at least partially within the end cover66. The pressure regulating valve68controls outlet pressure at an outlet70of the pressure regulation valve subassembly60by allowing excess flow to escape back into the reservoir34without being passed to the outlet70. The pressure regulating valve68can include an elastomeric closing element and a biasing spring to bias the elastomeric closing element closed such that the biasing spring is at least partially compressed when exposed to fuel pressure above a set point. As shown inFIG. 1, the outlet70of the pressure regulation valve subassembly60can be coupled to the flange26via a permanent, one-time use hose connection (e.g., a hose72pressed onto a barbed exterior portion of the outlet70causing plastic deformation in the hose72). The pressure regulation valve subassembly60may be solely supported at its upper end by engagement of the opening62with the outlet port52such that the bottom end of the pressure regulation valve subassembly60is free from connection to surrounding structure. As illustrated, the chamber in which the pressure regulating valve68is provided receives 100 percent of the flow from the outlet port52.

As best shown inFIG. 7, a twist-to-lock male-female interface is provided between the outlet port52and the opening62of the pressure regulation valve subassembly60that prevents axial separation of the pressure regulation valve subassembly60from the filter unit44once the pressure regulation valve subassembly60is rotated relative to the outlet port52from a first orientation to a second orientation. As used herein, preventing axial separation refers to positive axial locking such that axial separation is not possible without resorting to plastic deformation or breakage. Although the connection between the outlet port52and the pressure regulation valve subassembly60may allow the pressure regulation valve subassembly60to be freely rotatable back-and-forth between the first orientation and the second orientation, abutment of the pressure regulation valve subassembly60with an inside wall34A of the reservoir34in the assembled state of the fuel pump module20blocks the pressure regulation valve subassembly60from returning from the second orientation to the first orientation. Optionally, the pressure regulation valve subassembly60may include a projection66A (e.g., formed on the end cover66) facing the inside wall34A to further limit the allowable movement of the pressure regulation valve subassembly60inside the reservoir34. Once the filter unit44and the pressure regulation valve subassembly60are removed from the reservoir34as shown inFIG. 8, the pressure regulation valve subassembly60is easily detached from the outlet port52after rotating the pressure regulation valve subassembly60back to the first orientation. Despite the outlet port52being shown as a male fitting and the opening62shown as a female fitting, the male-female relationship may be reversed.

Returning toFIG. 7, it can be seen that at least one key76is provided on an exterior of the outlet port52, and the opening62is provided with a corresponding at least one key slot78in which the key76is receivable when the pressure regulation valve subassembly60is in the first orientation, for assembly and disassembly. In some embodiments, the key76and the key slot78are reversed such that the key slot78is provided on the outlet port52. Once the key76is sufficiently inserted axially into the key slot78, the key76comes into alignment with a circumferential slot or groove80that extends partially or fully around the opening62of the pressure regulation valve subassembly60such that the pressure regulation valve subassembly60may be rotated relative to the outlet port52to a position (the second orientation mentioned above) in which the key76is no longer aligned with the key slot78and axial separation is prevented. Rotation between the first orientation and the second orientation is less than 360 degrees (e.g., 180 degrees or less, 90 degrees or less, 45 degrees or less, etc.).

The filter unit44can be disconnected from the remainder of the fuel pump module20, removed and replaced while maintaining the fuel line connection (e.g., via hose72) between the pressure regulation valve subassembly60and the tank-mounting flange26. This is accomplished by removing the fuel pump module20from the fuel tank22by detaching the tank-mounting flange26and pulling the fuel pump module20out the tank opening. The fuel level sensor25may first be removed. Then, the guide rods28are detached and removed from the cover56. The submodule consisting of the pump unit24, the filter unit44, and the pressure regulation valve subassembly60is then lifted from the reservoir34. The mounting tabs56A and/or the reservoir34may deflect elastically to enable the separation between the mounting tabs56A and the openings58. With the submodule out of the reservoir34, the pressure regulation valve subassembly60is rotated relative to the outlet port52of the filter unit44from the second orientation to the first orientation as shown inFIG. 8. It will be understood that the relative rotation as referred to above may also be accomplished by holding the pressure regulation valve subassembly60stationary while rotating the remainder of the submodule. Once in the first orientation, the pressure regulation valve subassembly60is axially separated from the outlet port52. A plug-in connection between the pump unit24and the filter unit44is also separated, leaving the filter unit44entirely free from the remaining components. A new filter unit44identical to the illustrated and described filter unit44may be installed by reversing the above described procedure to extend the useful life of the fuel pump module20with minimal waste by not replacing components that are re-usable, such as the tank-mounting flange26, the pressure regulation valve subassembly60, and the jet pump54. In some instances, the procedure may additionally or alternately allow for servicing or replacing the pressure regulating valve68when the submodule is removed from the reservoir34. The pressure regulating valve68is accessed for service or replacement by temporary removal of the end cover66from the body64, which is then subsequently replaced or reinstalled. The end cover66may be provided with a slide-on interface, a twist-to-lock interface, or a threaded interface with the body64.

Although the pressure vessel40is described and illustrated as forming a filter unit44and enclosing a filter42such as a fabric filter element, the filter42may take any variety of other forms and may be omitted entirely, relying instead on filtering further upstream and/or downstream.

FIG. 9illustrates a portion of a fuel pump module120that may be identical in all respects toFIGS. 1-8and the above description, except where noted. Thus, the preceding disclosure is relied upon for features not specifically reiterated below. Although the pressure regulation valve subassembly160has an opening62engaged with the outlet port52as described above, the opening62does not form an inlet port directly providing fluid communication to the chamber in which the pressure regulating valve68is provided. Rather, the opening62at the upper end of the pressure regulation valve subassembly160extends directly and only to an outlet port145at the upper end such than none of the fuel from the outlet port52is conveyed directly to the chamber in which the pressure regulating valve68is provided. Although shown as a coaxial male fitting, the outlet port145may take any number of alternate forms. The outlet port145may be connected to the inlet of an external filter147(e.g., “fine filter”). From the filter147, filtered fuel is routed via parallel lines to the engine23and to the pressure regulation valve subassembly160via an inlet port170, which leads directly into the chamber in which the pressure regulating valve68is provided. Although the filter42is shown inside the pressure vessel40, the external filter147may be used in lieu of the internal filter42and the pressure vessel40may be empty as shown inFIG. 10. It is noted that the inlet port170ofFIG. 9is formed by a side port in the body164of the pressure regulation valve subassembly160that is identical in form to the side port forming the outlet70in the pressure regulation valve subassembly60ofFIGS. 1-8. Thus, the two variations may be produced via common mold tooling, or at least portions thereof, with minimal modification.

FIG. 10illustrates a portion of a fuel pump module220that may be identical in all respects toFIGS. 1-8and the above description, except where noted. Thus, the preceding disclosure is relied upon for features not specifically reiterated below. Although the pressure regulation valve subassembly260has an opening262engaged with the outlet port52as described above, the opening262does not form an inlet port directly providing fluid communication to the chamber in which the pressure regulating valve68is provided. Rather, the opening262at the upper end of the pressure regulation valve subassembly260extends as a through hole entirely through the body264to provide access to the outlet port52on an opposite side of the body264. As such, none of the fuel from the outlet port52is passed directly to the chamber in which the pressure regulating valve68is provided. Although not shown, the outlet port52may be connected to the inlet of an external filter (e.g., “fine filter”). From the filter, filtered fuel is routed via parallel lines to the engine23and back into the pressure regulation valve subassembly260via an inlet port270, which leads directly into the chamber in which the pressure regulating valve68is provided. It is noted that the inlet port270ofFIG. 10is formed by a side port in the body264of the pressure regulation valve subassembly260that is identical in form to the side port forming the outlet70in the pressure regulation valve subassembly60ofFIGS. 1-8. Thus, the two variations may be produced via common mold tooling, or at least portions thereof, with minimal modification.