Abstract:
A cover of a fuel supply module is adapted to disable a flow path through a designated port. An element is press-fit into the designated port to plug the designated port, and thermoplastic material is molded over an interface defined between the element and the designated port.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Patent Application No. 61/904,092, filed on Nov. 14, 2013, the entire contents of which are incorporated by reference herein. 
     
    
     BACKGROUND 
       [0002]    The invention relates to plugs for blocking fluid ports. Some aspects of the invention also relate to plugging a port within a vehicular fuel supply module. 
         [0003]    Fuel supply modules have molded parts with various fluid channels formed therein. With increasingly difficult space constraints in vehicles, fuel tanks can assume complex shapes with small openings and limited space for assembly and mounting of a fuel supply module, and fuel supply modules may need to be designed with special care to reduce dimensions to enable assembly. In some cases, a fuel supply module may be manufactured with a port which is not utilized in all applications. A molded plug may be assembled with the unused port and ultrasonically welded to the port. However, this requires multiple manufacturing steps, and may raise concerns regarding added cost and contamination. 
       SUMMARY 
       [0004]    In one aspect, the invention provides a method of modifying a fuel supply module to disable a flow path. A cover is provided having an interface configured to sealingly engage with a pressure vessel of a fuel supply module, the cover having a plurality of ports configured to define a plurality of flow paths through the cover. An element is press-fit into a designated one of the plurality of ports to plug the designated port. At least a portion of the cover with the element is inserted into a mold cavity, and thermoplastic material is injected into the mold cavity directly around an interface defined between the element and the designated port to overmold the interface, while using the element as a molding core. 
         [0005]    In another aspect, the invention provides a fuel supply module including a fuel pump operable to pump fuel when energized. A pressure vessel is coupled to the fuel pump to receive fuel from the fuel pump. A cover coupled to the pressure vessel to enclose a volume defined by the pressure vessel. The cover includes at least three fluid ports and a designated one of the at least three fluid ports is plugged by an element positioned within the designated port. The interface between the element and the designated port is overmolded with thermoplastic material. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is perspective view of a fuel pump module. 
           [0007]      FIG. 2  is a cross-section view of the fuel pump module, taken along line  2 - 2  of  FIG. 1 . 
           [0008]      FIG. 3  is perspective view of a cover of the fuel pump module shown in  FIGS. 1 and 2 . 
           [0009]      FIG. 4  is a perspective view of an alternate pressure regulating valve tube for use in the fuel pump module. 
           [0010]      FIG. 5  is a cross-section view of the alternate pressure regulating valve tube, taken along line  5 - 5  of  FIG. 4 . 
           [0011]      FIG. 6  is a cross-section view illustrating the introduction of a ball into a port of the cover of  FIG. 3 . 
           [0012]      FIG. 7  is a cross-section view illustrating the ball press fit into the port and overmolded with a plug. A molding tool is shown in dashed lines. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    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. 
         [0014]    As shown in  FIG. 1 , a fuel supply module or fuel pump module  20  includes a fuel pump or “pump unit”  24  operable to pump liquid fuel when energized. The pump module  20  can be positioned inside a fuel tank for supplying fuel to a fuel burning device, such as an internal combustion engine. The pump module  20  is oriented vertically within the tank, with a pump pickup and a coarse filter  28  at a first or bottom end, and an axis of the pump unit  24  arranged upright or vertically. The pump unit  24  is positioned in a receptacle area  30  of a housing  32 . The pump unit  24  can be insertable into the receptacle area  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  38  of its own. 
         [0015]    The housing  32  defines a pressure vessel  40  receiving the fuel from the pump unit  24 . The pressure vessel  40  can constitute a majority portion of the housing  32 . In other constructions, the pressure vessel  40  is separate from the structure retaining the fuel pump unit  24 , rather than being integrated with the housing  32  to include the receptacle area  30 . The pressure vessel  40  can accommodate a fine filter  42  as shown. Fuel is pumped via the pump unit  24  through the pressure vessel  40  (and the fine filter  42 , if equipped) and out to the engine or other device. As illustrated in  FIGS. 1 and 2 , the fuel outlet of the pump module  20  to the engine is via an outlet port  52  or primary supply outlet. 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 . 
         [0016]    Fuel is sent from the pump unit  24  directly into a hydraulic channel  60  formed in the housing  32  as shown in  FIG. 2 . In normal operation,  100  percent or all of the fuel pumped by the pump unit  24  enters the channel  60 . The channel  60  receiving the fuel from the pump unit  24  can be located substantially at a radially outward portion of the pressure vessel  40 . The channel  60  can extend circumferentially around a portion of the housing  32  (e.g., about one-third or 120 degrees). As illustrated, the channel  60  is positioned at an upper edge of the housing  32  at an outer peripheral portion thereof, and the channel  60  has a rectangular cross-sectional shape, defined in part by a radially inner wall  60 A and a radially outer wall  60 B. The channel  60  directly borders the pressure vessel  40 , with the wall  60 A being shared therebetween. The channel  60  terminates at a manifold  62 , from which the fuel is directed through a check valve  64 , into the pressure vessel  40 , exiting through a pressure vessel outlet port  68  and the outlet port  52  of the pump module  20 . The check valve  64  can have a receptacle or housing portion  72  that is integrally formed as a single piece with the housing  32  as shown, or constructed as a separate piece as a drop-in component into the housing  32 . The housing portion  72  can have a shared wall with the pressure vessel  40  as shown in  FIGS. 2 and 3 . The check valve  64  allows flow from the pump unit  24  into the pressure vessel  40  and prevents flow in the reverse direction. In the illustrated construction, the flow through the check valve  64  is vertically upward. 
         [0017]    From the manifold  62 , without first being directed through the check valve  64 , or any check valve whatsoever, a portion of the flow from the pump unit  24  can also drive a jet pump  76  to draw fuel toward the immediate area of the pump module  20  from a remote tank area. Thus, any portion of the pumped fuel not directed through the check valve  64  to the pressure vessel  40  is directed through the jet pump  76 , and vice versa. 
         [0018]    Pressure regulation/relief is achieved with a pressure regulation valve  80  located in communication with an outlet passage  90  positioned between the pressure vessel  40  and the outlet port  52 . The housing  32  includes a receptacle  82  integrally formed as a single piece therewith and configured to receive the pressure regulation valve  80 . The pressure regulation valve  80  is fluidly coupled with the outlet port  52  via a connection pipe  86 , which is coupled between the regulator receptacle  82  at a lower end and a receptacle port  88  of the cover  56  at an upper end. Along with the outlet passage  90 , the upper receptacle port  88  can be formed integrally as a single piece with the cover  56  such that the connection pipe  86  is installed into place simultaneously as the cover  56  is assembled with the housing  32 . The cover  56  can be assembled with the housing  32  in a sealing manner (e.g., by a hot plate weld process). 
         [0019]    The pump module  20  of  FIGS. 1 and 2  and the majority of components thereof, including the cover  56 , can be reconfigured for alternate service applications in which the outlet port  52  is disabled or blocked so that it is fluidly sealed shut. In such applications, the outlet port  52  is plugged as discussed below. Blocking of the outlet port  52  of the cover  56  may be done when the pump module  20  is configured for use within a small diameter reservoir that prevents connection of a fluid line to the outlet port  52  due to interference. In such instances, an alternate connection pipe  86 A ( FIGS. 4 and 5 ) can be provided coupled to the receptacle port  88  to establish fluid communication with the outlet passage  90  in the cover  56 . The alternate connection pipe  86 A includes an additional side port  106  serving as the principal or final outlet of the pump module  20 , which supplies fuel to the engine or other device. The alternate connection pipe  86 A can contain the pressure regulation valve  80  and may be referred to as a pressure regulation valve tube or PRV tube. The side port  106  of the PRV tube  86 A is utilized to provide the pump module  20  with a principal or final outlet that is spaced below the cover  56 . The side port  106  is angled to direct fuel outward from the main passage of the PRV tube  86 A (shown vertical) at an upward angle. 
         [0020]    As described above, the cover  56  includes the pressure vessel outlet port  68  that acts as an inlet to the cover  56 , receiving fuel from the volume of the pressure vessel  40 . The outlet passage  90  of the cover  56  is oriented generally perpendicular to the pressure vessel outlet port  68 . The outlet passage  90  intersects with the receptacle port  88 , or a passage terminating at the receptacle port  88 , and continues past the receptacle port  88  to the outlet port  52 . The receptacle port  88  and corresponding passage are generally perpendicular to the outlet passage  90 . 
         [0021]    In order to block the outlet port  52 , a two-part method can be performed. First, an element  100  is inserted into the outlet port  52  as a plug or stopper to block the fluid communication through the outlet port  52 . Additionally, as detailed below, the resulting interface between the element  100  and the outlet port  52  can be overmolded with thermoplastic material as shown in  FIG. 7 . As illustrated in  FIGS. 6 and 7 , the element  100  can be a ball. The element  100  can be constructed of an engineering thermoplastic such as polyoxymethylene (POM) or similar material. The element  100  can be pressed into the port  52  and used as a pseudo-core for molding the thermoplastic material to form a plug or cap  110 , finally closing off the outlet port  52 . The element  100  can be slightly larger in diameter than the inner diameter of the port  52  so that a press fit is achieved (e.g.,  5  to  6  percent strain). However, in some constructions, the press fit is not configured to or physically able to maintain a fluid seal on its own to maintain sealed fluid blockage of the outlet port  52  during operation at maximum design pressure. Although the element  100  may contribute to the ability to block flow through the outlet port  52 , the element  100  can be used primarily as a placeholder that obviates the need for a support core inserted into the receptacle port  88  (which receives the PRV tube  86 A) during overmolding of the cap  110 .  FIG. 7  schematically illustrates an injection molding tool, including a mold cavity, as shown in dashed lines. The arrow indicates the flow of injected liquid thermoplastic material into the mold cavity to form the cap  110 . Once overmolding of the cap  110  is complete, the element  100  remains in place. 
         [0022]    The cap  110  secures the element  100  against removal and provides a secondary blockage in the outlet port  52  that may provide a majority of the blocking strength against internal fluid pressure. Although the cap  110  can be provided solely inside the outlet port  52  in some constructions, the cap  110  may extend about an exterior of the protruding male portion that forms the outlet port  52 . Barbs  114  that may have sharp edges (showing as sharp corners in cross-section) are provided on the outside of the outlet port  52 . The sharp edges promote melting and bonding with the overmolded material of the cap  110  during molding.  FIGS. 6 and 7  show an alternate arrangement of the barbs  114  having an enhanced array of sharp edges as compared to the basic barb configuration of  FIGS. 1-3 . The barbs  114  can include a plurality of annular ribs that extend substantially radially outward with respect to an axis A defined by the outlet port  52 . At least two of the annular ribs  114  can have different cross-sectional shapes as shown in  FIGS. 6 and 7 . In addition to the radially extending ribs, additional barbs can provide additional sharp edges  116  adjacent the tip of the protruding male portion. The additional sharp edges  116  are spaced apart with respect to both an axial direction and a radial direction from the various corners defined by the radially extending ribs  114 . It should be understood that a variety of different configurations of barbs, ribs, and or sharp corners or edges are contemplated, an exhaustive depiction of which cannot reasonably be included herein. 
         [0023]    Mechanical retention of the cap  110  onto the outlet port  52  is also promoted by the shrink rate of the injection molded material forming the cap  110 , which can be about  3  percent. The overmolded cap  110  can be a material the same as or similar to the material (e.g., POM) of the element  100  pressed into the outlet port  52 . 
         [0024]    The process of adapting or re-configuring the cover  56  includes sealing the outlet port  52  closed simultaneously with the molding operation that forms the cap  110 . The process further includes utilizing a press fit polymer element  100  as a core for the overmolding operation of the cap  110 , with the element  100  remaining in-situ in the final plugged port  52 .