Abstract:
An internal fuel filter for a pressure regulator having a body that encloses a fuel flow path. A first support includes a first surface adapted to be sealingly surrounded by the body. A second support is spaced from the first support along an axis. At least one rib is disposed between and contiguous with the first and second supports, wherein one of the rib and the second support includes a second surface adapted to sealingly surrounded the body. A filter element extends between the first support and the second support and surrounds the axis.

Description:
CROSS REFERENCE TO CO-PENDING APPLICATION  
       [0001]    This application claims the benefit of the earlier filing date of U.S. Provisional Application 60/168,744, filed Dec. 6, 1999, the disclosure of which is incorporated by reference herein in its entirety. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    A filter for a fuel pressure regulator for automotive fuel systems, and more particularly to a filter that is mounted internal to the pressure regulator housing.  
         BACKGROUND OF THE INVENTION  
         [0003]    It is believed that most modern automotive fuel systems utilize fuel injectors to deliver fuel to the engine cylinders for combustion. It is believed that these fuel injectors are connected to a fuel rail to which fuel is supplied by a pump. It is also believed that the pressure at which the fuel is supplied to the fuel rail must be regulated to ensure the proper operation of the fuel injectors. It is believed that such regulating is carried out using pressure regulators that control the pressure of the fuel in the system at all engine speeds, i.e., as measured in revolutions per minute.  
           [0004]    It is believed that conventional fuel pressure regulators include the flow-through type and non-flow-through type as disclosed in commonly-assigned U.S. Pat. No. 5,509,444 to Robinson et al. and U.S. Pat. No. 5,413,077 to Hornby et al., respectively, which are incorporated herein in their entirety by reference.  
           [0005]    It is believed to be necessary to filter the fuel flowing through the pressure regulators to remove impurities and ensure proper operation of the components on the fuel rail, such as the fuel injectors. To achieve this purpose, it is believed that filters have been mounted on an external surface of pressure regulators, and that these external filters are subject to damage and accidental removal during assembly, testing, handling, and installation into a vehicle. It is also believed that filters have been mounted internal to the pressure regulator, and that these internal filters are protected from inadvertent damage and removal, but provide a limited filter area that has proven to be inadequate. It is believed that a fuel filter is needed that is protected from damage and provides a sufficiently large filtration area.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention provides an internal fuel filter for a pressure regulator that has a body that encloses a fuel flow path. The filter comprises a first support that includes a first surface adapted to be sealingly surrounded by the body, a second support that is spaced from the first support along an axis, at least one rib that is disposed between and contiguous with the first and second supports, and a filter element that extends between the first support and the second support and surrounds the axis. The at least one rib and the second support include a second surface adapted to sealingly surrounded the body.  
           [0007]    The present invention also provides an internal fuel filter for a pressure regulator that has a body that encloses a fuel flow path. The filter comprises a first support that includes a first surface adapted to be sealingly surrounded by the body, a second support that is spaced from the first support along an axis and includes a second surface adapted to sealingly surrounded the body, at least one rib that is disposed between and contiguous with the first and second supports, and a filter element that extends between the first support and the second support and surrounds the axis.  
           [0008]    The present invention further provides an internal fuel filter for a pressure regulator that has a body that encloses a fuel flow path. The filter comprises a first support that includes a first surface adapted to be sealingly surrounded by the body, a second support that is spaced from the first support along an axis, at least one rib that is disposed between and contiguous with the first and second supports, and a filter element extends between the first support and the second support and surrounds the axis. The at least one rib includes a second surface adapted to sealingly surrounded the body.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate presently preferred embodiments of the invention and, together with the general description given above and the detailed description given below, serve to explain features of the invention.  
         [0010]    [0010]FIG. 1A is a side view of a fuel filter according to a first embodiment of the present invention.  
         [0011]    [0011]FIG. 1B is a top view of the fuel filter shown in FIG. 1A.  
         [0012]    [0012]FIG. 1C is a cross-sectional view of the fuel filter shown in FIG. 1A, the cross-section being taken along line  1 C- 1 C in FIG. 1B.  
         [0013]    [0013]FIG. 1D is a cross-sectional view of the fuel filter shown in FIG. 1A, the cross-section being taken along line  1 D- 1 D in FIG. 1B.  
         [0014]    [0014]FIG. 2A is a side view of a fuel filter according to a second embodiment of the present invention.  
         [0015]    [0015]FIG. 2B is a top view of the fuel filter shown in FIG. 2A.  
         [0016]    [0016]FIG. 2C is a cross-sectional view of the fuel filter shown in FIG. 2A, the cross-section being taken along line  2 C- 2 C in FIG. 2B.  
         [0017]    [0017]FIG. 2D is a cross-sectional view of the fuel filter shown in FIG. 2A, the cross-section being taken along line  2 D- 2 D in FIG. 2B.  
         [0018]    [0018]FIG. 3A is a side view of a fuel filter according to a third embodiment of the present invention.  
         [0019]    [0019]FIG. 3B is a top view of the fuel filter shown in FIG. 3A.  
         [0020]    [0020]FIG. 3C is a cross-sectional view of the fuel filter shown in FIG. 2A, the cross-section being taken along line  3 C- 3 C in FIG. 3B.  
         [0021]    [0021]FIG. 3D is a cross-sectional view of the fuel filter shown in FIG. 2A, the cross-section being taken along line  3 D- 3 D in FIG. 3B.  
         [0022]    [0022]FIG. 4 is a cross-sectional view of a flow-through fuel pressure regulator with the fuel filter according to the third embodiment shown on the left side and the fuel filter according to the first embodiment shown on the right side.  
         [0023]    [0023]FIG. 5 is a cross-sectional view of a non-flow-through fuel pressure regulator with the fuel filter according to the third embodiment shown on the left side and the fuel filter according to the first embodiment shown on the right side. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0024]    A first embodiment of the fuel filter of the present invention will be described with reference to FIG. 1A- 1 D. As shown, the filter  10  has a first support  102  and a second support  104  offset along a filter axis A. The first and second supports  102 , 104  are connected with ribs  106  to define a filter frame  108 . A filter element  110  is attached to the frame  108  such that it surrounds the axis A, forming a generally cylindrical filter assembly. The frame  108  is substantially fluid-impermeable and the filter element  110  is substantially fluid-permeable.  
         [0025]    The first and second supports  102 , 104  can be annular. The first support  102  has a protrusion  112  on a portion of an inner circumference that can engage a first internal surface of a fuel pressure regulator. The protrusion  112  can extend along the entire inner circumference of the first support  102 , or can extend along a length of the first support  102  that is contiguous with the ribs  106 . The second support  104  has a sealing surface  114  on an outer circumference that can engage a second internal surface of a fuel pressure regulator. The protrusion  112  and sealing surface  114  create a flow path through at least a portion of the filter element  110  that is substantially perpendicular to the axis A.  
         [0026]    The supports  102 , 104  and ribs  106  can be made of a thermoplastic material, although other materials are considered to be within the scope of the invention. The filter element  110  can be a woven filter material that is insert molded into the frame  108  using a conventional process, thereby sealing the filter element  110  within the supports  102 , 104  and ribs  106 . The filter element  110  can be made from a single piece extending over the entire frame circumference, or from multiple pieces extending over a circumferential portion of the frame  108 . When multiple pieces are used, the ends can overlap before the insert molding process. One or more of the ribs  106  can have an increased circumferential dimension to accommodate overlapping ends of the filter material. The ribs  106  have an outer surface  116  oriented obliquely with respect to the filter axis A. The orientation of the outer surfaces  116  can aid in the removal of the filter element  10  from a mold during manufacture.  
         [0027]    An alternative filter embodiment  20  is shown in FIGS. 2A -  2 D. This embodiment has elements comparable to the first embodiment  10 , including a first support  202  and a second support  204  connected with ribs  206  to define a filter frame  208 , and a filter element  210  attached to the frame  208  such that it surrounds the axis A. The first support  202  has a protrusion  212  on a portion of an inner circumference that can engage a first internal surface of a fuel pressure regulator. The protrusion  212  can extend along the entire inner circumference of the first support  202 , or can extend along a length of the first support  202  contiguous with the ribs  206 . The second support  204  has a sealing surface  214  on an outer circumference that can engage a second internal surface of a fuel pressure regulator. The protrusion  212  and sealing surface  214  create a flow path through at least a portion of the filter element  210  that is substantially perpendicular to the axis A. The ribs  206  have an outer surface  216  that is oriented substantially parallel to the filter axis A. The orientation of the surfaces  216  can result in a lower mold manufacturing cost, since the fuel filter  20  is relatively geometrically simple.  
         [0028]    Another alternative filter embodiment  30  is shown in FIGS.  3 A- 3 D. This embodiment has elements comparable to the other embodiments  10 , 20 , including a first support  302  and a second support  304  connected with ribs  306  to define a filter frame  308 , and a filter element  310  attached to the frame  308  such that it surrounds the axis A. At least one rib has a protrusion  312  on a portion of an inner circumference that can engage a first internal surface of a fuel pressure regulator. The protrusion  312  can extend along the entire inner circumference of the at least one rib  306 , or can extend along a portion of a length of the at least one rib  306 . Further, protrusions can be disposed on each of the ribs  306 . The second support  304  has a sealing surface  314  on an outer circumference that can engage a second internal surface of a fuel pressure regulator. The protrusion  312  and sealing surface  314  create a flow path through at least a portion of the filter element  310  that is substantially perpendicular to the axis A. The ribs  306  have an outer surface  316  that is oriented substantially parallel to the filter axis A. The orientation of the outer surfaces  316  can result in a lower mold manufacturing cost, thereby decreasing the cost of the fuel filter  30 .  
         [0029]    [0029]FIG. 4 shows examples of fuel filters according to the present invention installed in a flow-through fuel pressure regulator  40 . Fuel filters  10  and  30  are shown for illustrative purposes, although it is understood that a single filter  10 ,  20 , or  30  would be used at any given time. Further, fuel filter  20  would be installed in a similar manner.  
         [0030]    As shown, the protrusion  112  on the inner circumference of the first support  102  and the protrusions  312  on the inner circumference of the ribs  306 , respectively, engage an indentation  418  on an outer surface of the valve actuator housing  408 . The indentation  418  receives the protrusion or protrusions  112 , 312 , and retains the filter  10 , 30  in place. The sealing surface  114 , 314  on the outer circumference of the second support  104 , 304  engages an inner surface of the regulator housing  412 . The protrusion or protrusions  112 , 312 , and sealing surfaces  114 , 314 , define a flow path through the filter  10 , 30 . In operation, fuel enters the regulator  40  through the openings  410  in the lower housing  412 , then passes through the filter element  110 , 310  in a substantially radial direction (away from axis A) before proceeding through the valve seat  402  and the opening  414  in the upper regulator housing  416 .  
         [0031]    [0031]FIG. 5 shows an example of the fuel filters of the present invention installed in a non-flow-through fuel pressure regulator  50 . Fuel filters  10  and  30  are shown for illustrative purposes, although it is understood that a single filter  10 ,  20 , or  30  would be used at any given time. Further, fuel filter  20  would be installed in a similar manner.  
         [0032]    In regulator  50  the protrusion  112  on the inner circumference of the first support  102  and the protrusions  312  on the inner circumference of the ribs  306  of the filter  10 , 30 , respectively, engage an indentation an indentation  514  on an outer surface of the valve body  506 . The indentation  514  receives the protrusion or protrusions  112 , 312  and retains the filter  10 , 30  in place. The sealing surface  114 , 314  on the outer circumference of the second support  104 , 304  engages an inner surface of the regulator housing  508 . The protrusion or protrusions  112 , 312 , and sealing surfaces  114 , 314 , define a flow path through the filter  10 , 30 . In operation, fuel enters the valve body  506  through the opening  507  in its lower end, then passes through the valve seat  510  before passing through the filter element  110 , 310  in a substantially radial direction (towards axis A). The fuel then proceeds out of the regulator  50  through the openings  512  in the lower regulator housing  508 .  
         [0033]    While the invention has been disclosed with reference to certain preferred embodiments, numerous modifications, alterations, and changes to the described embodiments are possible without departing from the sphere and scope of the invention, as defined in the appended claims and their equivalents thereof. Accordingly, it is intended that the invention not be limited to the described embodiments, but that it have the full scope defined by the language of the following claims.