Abstract:
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.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority to U.S. Provisional Patent Application No. 62/042,628, filed Aug. 27, 2014, the entire contents of which are hereby incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    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 
       [0003]    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. 
         [0004]    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. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a schematic view of a fuel supply system for a motor vehicle including a fuel pump module according to one embodiment. 
           [0006]      FIG. 2  is an exploded assembly view of the fuel pump module of  FIG. 1 . 
           [0007]      FIG. 3  is a top view of a portion of the fuel pump module of  FIG. 1 . 
           [0008]      FIG. 4  is a perspective view of the portion of the fuel pump module shown in  FIG. 3 . 
           [0009]      FIG. 5  is a side view of the fuel pump module with a portion of a reservoir wall removed to illustrate a pressure regulating valve subassembly in an assembled orientation. 
           [0010]      FIG. 6  is a cross-section view taken along line  6 - 6  of  FIG. 3 . 
           [0011]      FIG. 7  is a perspective view of the interfacing ends of a filter unit outlet port and the pressure regulating valve subassembly. 
           [0012]      FIG. 8  is a perspective view showing a disassembly sequence for removing the filter unit from the fuel pump module. 
           [0013]      FIG. 9  is a cross-section view of a fuel pump module according to another embodiment 
           [0014]      FIG. 10  is a cross-section view of a fuel pump module according to yet another embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. 
         [0016]    As shown in  FIG. 1 , a fuel supply module or fuel pump module  20  is provided as part of a fuel supply system for a motor vehicle. The fuel pump module  20  is positioned within a fuel tank  22  of the motor vehicle for supplying fuel to a fuel burning device, such as an internal combustion engine  23 . The pump module  20  includes a fuel pump, or pump unit  24  operable to pressurize liquid fuel when energized for movement though the system. The pump unit  24  is positioned in a receptacle  30  of a housing  32 . The pump unit  24  can be insertable into the receptacle  30  in the axial or vertical direction and can be retained with a clip  36  or other device. In other constructions, the pump unit  24  may be positioned relative to the housing  32  in other ways. Although positionally retained in relation to the housing  32 , the pump unit  24  also includes a case or housing of its own. The pump unit  24  defines an inlet  24 A (e.g., at a bottom end) and an outlet  24 B (e.g., at an upper end) between which the pump unit  24  includes a mechanism for pressurizing fuel. Although not shown, an inlet filter or strainer may be provided at the inlet  24 A. A reservoir  34  defining a cup-like fuel chamber at least partially receives the pump unit  24  and the housing  32  such that the pump unit  24  is submerged in a relatively consistent level of fuel independent of the prevailing level or potential sloshing within the tank  22 . A fuel level sensor  25  supported by the fuel pump module  20  is operable to sense a fuel level outside the reservoir  34  within the tank  22 . The fuel level sensor  25  can be a float type as shown or another type of level sensor.  FIG. 2  shows components of the fuel pump module  20  in an exploded assembly view. 
         [0017]    A tank-mounting flange  26  is provided at a top end of the fuel pump module  20  such that the housing  32  and the pump module  20  are suspended below by a plurality of guide rods  28 . The flange  26  resides in an opening of the fuel tank  22  and has an exterior surface provided with hydraulic and electrical connections for communication between the fuel pump module  20  and the engine  23 , the environment, an electrical power source (e.g., battery), and an electronic controller. The flange  26  can include fuel send and return ports  26 A,  26 B, a vent port  26 C, and an electronic plug connection  26 D. 
         [0018]    The housing  32  defines a pressure vessel  40  ( FIG. 6 ) receiving the fuel pressurized by the pump unit  24 . The pressure vessel  40  can constitute a majority portion of the housing  32 . The pressure vessel  40  can be utilized for defining a volume directly surrounding a filter  42 . Thus, the pressure vessel  40  can be part of a filter unit  44  positioned alongside and functionally downstream of the pump unit  24 . Fuel is pumped via the pump unit  24  through a check valve (not shown) to the pressure vessel  40  and out an outlet port  52  toward the engine  23  via the flange  26 .  FIG. 6  illustrates a portion of an intermediate channel  46  in the housing  32  which directs fuel from the outlet  24 B of the pump unit  24  into the pressure vessel  40 . An auxiliary outlet from the housing  32  between the pump outlet  24 B and the pressure vessel  40  drives a jet pump  54  which continually operates to pump fuel from the tank  22  into the reservoir  34 . The illustrated outlet port  52  is formed integrally as a single piece with a cover  56  located at an upper end of the pressure vessel  40 . The cover  56  may be permanently affixed to the housing  32  to define the pressure vessel  40  (e.g., by hot plate welding or other type of non-serviceable connection which is not removable without destructive means). 
         [0019]    The cover  56  includes a plurality of mounting tabs  56 A at a periphery thereof. Each of the mounting tabs  56 A extends outwardly away from the pressure vessel  40  and physically interferes with the reservoir  34  in top view ( FIG. 3 ). An aperture  56 B is provided through each of the mounting tabs  56 A, the apertures  56 B receiving corresponding ones of the guide rods  28 . Just below its top edge, the reservoir  34  is provided with corresponding openings  58  for receiving the mounting tabs  56 A. The reservoir  34  can be flexed and elastically deformed to allow the mounting tabs  56 A to be positioned into the corresponding openings  58  at the time of assembly. Once assembled, the guide rods  28  prevent movement that may otherwise lead to disassembly of the housing  32 , and thus the filter unit  44  and the pump unit  24 , from the reservoir  34 , and the position of the fuel pump module  20  within the tank  22  is maintained during normal operation. 
         [0020]    A pressure regulation valve subassembly  60  includes an opening  62  coupled to the outlet port  52 , which forms the outlet of the pressure vessel  40  and of the filter unit  44  as a whole. The opening  62  forms an inlet port of the pressure regulation valve subassembly  60  as shown. The connection between the pressure regulation valve subassembly  60  and the outlet port  52  is discussed in further detail below. The pressure regulation valve subassembly  60  has a tubular body  64  extended at a 90-degree angle from the opening  62 , the body  64  extending generally downward away from the flange  26  toward a bottom wall of the reservoir  34  to terminate at an end cover  66  at its lower end. A pressure regulating valve  68  is positioned within a chamber of the pressure regulation valve subassembly  60 , for example, at a bottom of the body  64 , at least partially within the end cover  66 . The pressure regulating valve  68  controls outlet pressure at an outlet  70  of the pressure regulation valve subassembly  60  by allowing excess flow to escape back into the reservoir  34  without being passed to the outlet  70 . The pressure regulating valve  68  can 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 in  FIG. 1 , the outlet  70  of the pressure regulation valve subassembly  60  can be coupled to the flange  26  via a permanent, one-time use hose connection (e.g., a hose  72  pressed onto a barbed exterior portion of the outlet  70  causing plastic deformation in the hose  72 ). The pressure regulation valve subassembly  60  may be solely supported at its upper end by engagement of the opening  62  with the outlet port  52  such that the bottom end of the pressure regulation valve subassembly  60  is free from connection to surrounding structure. As illustrated, the chamber in which the pressure regulating valve  68  is provided receives 100 percent of the flow from the outlet port  52 . 
         [0021]    As best shown in  FIG. 7 , a twist-to-lock male-female interface is provided between the outlet port  52  and the opening  62  of the pressure regulation valve subassembly  60  that prevents axial separation of the pressure regulation valve subassembly  60  from the filter unit  44  once the pressure regulation valve subassembly  60  is rotated relative to the outlet port  52  from 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 port  52  and the pressure regulation valve subassembly  60  may allow the pressure regulation valve subassembly  60  to be freely rotatable back-and-forth between the first orientation and the second orientation, abutment of the pressure regulation valve subassembly  60  with an inside wall  34 A of the reservoir  34  in the assembled state of the fuel pump module  20  blocks the pressure regulation valve subassembly  60  from returning from the second orientation to the first orientation. Optionally, the pressure regulation valve subassembly  60  may include a projection  66 A (e.g., formed on the end cover  66 ) facing the inside wall  34 A to further limit the allowable movement of the pressure regulation valve subassembly  60  inside the reservoir  34 . Once the filter unit  44  and the pressure regulation valve subassembly  60  are removed from the reservoir  34  as shown in  FIG. 8 , the pressure regulation valve subassembly  60  is easily detached from the outlet port  52  after rotating the pressure regulation valve subassembly  60  back to the first orientation. Despite the outlet port  52  being shown as a male fitting and the opening  62  shown as a female fitting, the male-female relationship may be reversed. 
         [0022]    Returning to  FIG. 7 , it can be seen that at least one key  76  is provided on an exterior of the outlet port  52 , and the opening  62  is provided with a corresponding at least one key slot  78  in which the key  76  is receivable when the pressure regulation valve subassembly  60  is in the first orientation, for assembly and disassembly. In some embodiments, the key  76  and the key slot  78  are reversed such that the key slot  78  is provided on the outlet port  52 . Once the key  76  is sufficiently inserted axially into the key slot  78 , the key  76  comes into alignment with a circumferential slot or groove  80  that extends partially or fully around the opening  62  of the pressure regulation valve subassembly  60  such that the pressure regulation valve subassembly  60  may be rotated relative to the outlet port  52  to a position (the second orientation mentioned above) in which the key  76  is no longer aligned with the key slot  78  and 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.). 
         [0023]    The filter unit  44  can be disconnected from the remainder of the fuel pump module  20 , removed and replaced while maintaining the fuel line connection (e.g., via hose  72 ) between the pressure regulation valve subassembly  60  and the tank-mounting flange  26 . This is accomplished by removing the fuel pump module  20  from the fuel tank  22  by detaching the tank-mounting flange  26  and pulling the fuel pump module  20  out the tank opening. The fuel level sensor  25  may first be removed. Then, the guide rods  28  are detached and removed from the cover  56 . The submodule consisting of the pump unit  24 , the filter unit  44 , and the pressure regulation valve subassembly  60  is then lifted from the reservoir  34 . The mounting tabs  56 A and/or the reservoir  34  may deflect elastically to enable the separation between the mounting tabs  56 A and the openings  58 . With the submodule out of the reservoir  34 , the pressure regulation valve subassembly  60  is rotated relative to the outlet port  52  of the filter unit  44  from the second orientation to the first orientation as shown in  FIG. 8 . It will be understood that the relative rotation as referred to above may also be accomplished by holding the pressure regulation valve subassembly  60  stationary while rotating the remainder of the submodule. Once in the first orientation, the pressure regulation valve subassembly  60  is axially separated from the outlet port  52 . A plug-in connection between the pump unit  24  and the filter unit  44  is also separated, leaving the filter unit  44  entirely free from the remaining components. A new filter unit  44  identical to the illustrated and described filter unit  44  may be installed by reversing the above described procedure to extend the useful life of the fuel pump module  20  with minimal waste by not replacing components that are re-usable, such as the tank-mounting flange  26 , the pressure regulation valve subassembly  60 , and the jet pump  54 . In some instances, the procedure may additionally or alternately allow for servicing or replacing the pressure regulating valve  68  when the submodule is removed from the reservoir  34 . The pressure regulating valve  68  is accessed for service or replacement by temporary removal of the end cover  66  from the body  64 , which is then subsequently replaced or reinstalled. The end cover  66  may be provided with a slide-on interface, a twist-to-lock interface, or a threaded interface with the body  64 . 
         [0024]    Although the pressure vessel  40  is described and illustrated as forming a filter unit  44  and enclosing a filter  42  such as a fabric filter element, the filter  42  may take any variety of other forms and may be omitted entirely, relying instead on filtering further upstream and/or downstream. 
         [0025]      FIG. 9  illustrates a portion of a fuel pump module  120  that may be identical in all respects to  FIGS. 1-8  and the above description, except where noted. Thus, the preceding disclosure is relied upon for features not specifically reiterated below. Although the pressure regulation valve subassembly  160  has an opening  62  engaged with the outlet port  52  as described above, the opening  62  does not form an inlet port directly providing fluid communication to the chamber in which the pressure regulating valve  68  is provided. Rather, the opening  62  at the upper end of the pressure regulation valve subassembly  160  extends directly and only to an outlet port  145  at the upper end such than none of the fuel from the outlet port  52  is conveyed directly to the chamber in which the pressure regulating valve  68  is provided. Although shown as a coaxial male fitting, the outlet port  145  may take any number of alternate forms. The outlet port  145  may be connected to the inlet of an external filter  147  (e.g., “fine filter”). From the filter  147 , filtered fuel is routed via parallel lines to the engine  23  and to the pressure regulation valve subassembly  160  via an inlet port  170 , which leads directly into the chamber in which the pressure regulating valve  68  is provided. Although the filter  42  is shown inside the pressure vessel  40 , the external filter  147  may be used in lieu of the internal filter  42  and the pressure vessel  40  may be empty as shown in  FIG. 10 . It is noted that the inlet port  170  of  FIG. 9  is formed by a side port in the body  164  of the pressure regulation valve subassembly  160  that is identical in form to the side port forming the outlet  70  in the pressure regulation valve subassembly  60  of  FIGS. 1-8 . Thus, the two variations may be produced via common mold tooling, or at least portions thereof, with minimal modification. 
         [0026]      FIG. 10  illustrates a portion of a fuel pump module  220  that may be identical in all respects to  FIGS. 1-8  and the above description, except where noted. Thus, the preceding disclosure is relied upon for features not specifically reiterated below. Although the pressure regulation valve subassembly  260  has an opening  262  engaged with the outlet port  52  as described above, the opening  262  does not form an inlet port directly providing fluid communication to the chamber in which the pressure regulating valve  68  is provided. Rather, the opening  262  at the upper end of the pressure regulation valve subassembly  260  extends as a through hole entirely through the body  264  to provide access to the outlet port  52  on an opposite side of the body  264 . As such, none of the fuel from the outlet port  52  is passed directly to the chamber in which the pressure regulating valve  68  is provided. Although not shown, the outlet port  52  may 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 engine  23  and back into the pressure regulation valve subassembly  260  via an inlet port  270 , which leads directly into the chamber in which the pressure regulating valve  68  is provided. It is noted that the inlet port  270  of  FIG. 10  is formed by a side port in the body  264  of the pressure regulation valve subassembly  260  that is identical in form to the side port forming the outlet  70  in the pressure regulation valve subassembly  60  of  FIGS. 1-8 . Thus, the two variations may be produced via common mold tooling, or at least portions thereof, with minimal modification.