Patent Publication Number: US-6666190-B1

Title: Integrated fuel delivery and electrical connection for electronic fuel injectors

Description:
BACKGROUND OF INVENTION 
     a. Field of Invention 
     The invention relates generally to fuel injectors, and, more particularly to an improved apparatus and method for delivering fuel via fuel injectors, and electrically wiring fuel injectors in an internal combustion engine. 
     b. Description of Related Art 
     Modern internal combustion engines generally include electronic fuel injectors for delivering fuel into the combustion chamber. Known fuel injector types include, for example, top, bottom and side feed fuel injectors in which fuel is respectively delivered adjacent the top, bottom or side of the fuel injector. 
     Conventional top feed fuel injectors generally require a bulky electrical connector mounted adjacent to the top of the injector body. These bulky electrical connectors increase assembly complexity and consume valuable space needed for component packaging. During engine repair or manufacturing, conventional electrical connectors can often be difficult to access. Moreover, conventional injector wiring harnesses can be difficult to secure in the compact engine spaces, are often poorly defined due to the lack of adequate spacing, and may themselves unnecessarily consume packaging space. 
     As engine s become increasingly complex and compact, the space available for mounting fuel injectors, fuel rails, and electrical wiring harnesses becomes increasingly limited. 
     Various conventional very systems and electrical connectors for fuel injectors are known and disclosed, for example, in U.S. Pat. No. 6,338,333 to Brosseau et al. ( grosseau) and U.S. Pat. No. 6,260,537 to Lamb et al. ( Lamb). 
     U.S. Pat. No. 6,338,333 to Brosseau discloses an integrated fuel delivery system for fuel injectors in an internal combustion engine. Brosseau however does not address the electrical connections to fuel injectors or the wire harness layout, which factor into the drawbacks of today&#39;s conventional fuel injection system designs. U.S. Pat. No. 6,260,537 to Lamb discloses bottom feed fuel injectors with electrical wiring connections on top. As for Brosseau, Lamb also does not simplify electrical connections for fuel injectors so as to facilitate the installation and testing thereof. 
     For the U.S. Patents cited above, from a design and manufacturing standpoint, the manufacture of the relatively complicated fuel delivery and electrical connection systems of the past has resulted in a noticeable increase in the overall manufacturing cost of vehicles, which are typically manufactured by the hundreds of thousands. From an assembly standpoint, the assembly and installation of complex electrical connectors and wiring harnesses can be time-consuming and burdensome, and can further add to the overall cost of a vehicle. Lastly, from a maintenance and use standpoint, improvements in conventional electrical connectors and fuel delivery systems of today&#39;s internal combustion engines would likewise provide improvement in the durability of such engines. 
     SUMMARY OF INVENTION 
     The invention solves the problems and overcomes the drawbacks and disadvantages of the prior art fuel injection systems by providing an integrated fuel delivery and electrical connection system for fuel injectors in an internal combustion engine. 
     Thus, an aspect of the present invention is to provide a fuel delivery system which incorporates the electrical contacts of a conventional electrical connector into the fuel rail assembly. 
     Another aspect of the present invention is to provide fuel injectors having integral electrical connections for contact with the electrical contacts on the fuel delivery system of the present invention. 
     Yet another aspect of the present invention is to eliminate or substantially reduce the need for external wire harness routing. 
     Another aspect of the present invention is to provide a single point wiring harness connection for electrical connection to the fuel injectors. 
     Yet another aspect of the present invention is to provide a method for testing fuel injection systems before final engine assembly, and simplifying injector installation and removal. 
     The invention accomplishes these aspects by providing an integrated fuel delivery and electrical connection system generally including an electrical bus, a fuel delivery tube and fuel injectors. The electrical bus may include openings for insertion and connection of fuel injectors. The electrical bus may further include positive electrical contacts for electrical connection to a respective fuel injector positive electrical contact and ground contacts for grounding a fuel injector ground contact. The fuel delivery tube may include openings for insertion and connection of fuel injectors, and may be connected to the electrical bus. A portion of each of the fuel injectors may be inserted into each of the openings in the electrical bus and fuel delivery tube to thereby connect each fuel injector to the electrical bus and fuel delivery tube. 
     For the fuel delivery and electrical connection system described above, each of the positive electrical contacts in the electrical bus may be mounted at a first radial distance from a central longitudinal axis of the electrical bus and the ground contact in the electrical bus may be mounted at a second radial distance from the central axis. The first radial distance may be less than the second radial distance, greater than the second radial distance, or approximately equal to the second radial distance. The electrical bus may further include an electrical environmental seal for preventing contamination of the positive and ground contacts of the electrical bus and the fuel injector upon connection thereof with the positive and ground contacts on the fuel injector. A plurality of electrical wires may be connected to each of the positive and ground contacts in the electrical bus and terminate at a generally single connection point on the electrical bus. The electrical bus and the fuel delivery tube may be fabricated as a single unit or as separate components of an assembly. The fuel injector positive electrical contact may be mounted at a first axial distance from a fuel injector end surface along a fuel injector central longitudinal axis and the fuel injector ground contact may be mounted at a second axial distance from the fuel injector end surface along the fuel injector central longitudinal axis. The first axial distance may be less than the second axial distance, greater than the second axial distance, or approximately equal to the second axial distance. The fuel injector positive and ground contacts may each be located at a predetermined location along the fuel injector central longitudinal axis and disposed substantially along opposite surfaces of the fuel injector. The fuel injector may further include an electrical environmental seal for preventing contamination of the positive and ground contacts of the electrical bus and the fuel injector upon connection thereof with the fuel injector positive and ground contacts. 
     The present invention also provides a method of installing an integrated fuel delivery and electrical connection system in an internal combustion engine. The method may include the step of inserting fuel injectors into an opening in an electrical bus. The electrical bus may include positive electrical contacts for electrical connection to fuel injector positive electrical contacts and ground contacts for grounding fuel injector ground contacts. The method may further include the step of connecting the electrical bus and fuel injectors to a fuel delivery tube. The fuel delivery tube may include corresponding openings for insertion and connection of the fuel injectors. The method may yet further include the step of connecting a single electrical harness to the electrical bus to provide electricity to the system. 
     For the method described above, the method may further include the steps of affixing the positive electrical contact in the electrical bus at a first radial distance from a central longitudinal axis of the electrical bus and affixing the ground contact in the electrical bus at a second radial distance from the central longitudinal axis. The first radial distance may be less than the second radial distance, greater than the second radial distance, or approximately equal to the second radial distance. The method may further include the step of providing an electrical environmental seal in the electrical bus for preventing contamination of the positive and ground contacts of the electrical bus and the fuel injector upon connection thereof with the fuel injector positive and ground contacts. The electrical bus may be made of a non-conductive material such as plastic. The method may further include the steps of connecting electrical wires to each of the positive and ground contacts in the electrical bus. The electrical wires may terminate at a generally single connection point on the electrical bus. The electrical bus and the fuel delivery tube may be fabricated as a single unit or as separate components. The method may further include the steps of affixing the positive electrical contact on the fuel injector at a first axial distance from a fuel injector end surface along a fuel injector central longitudinal axis, and affixing the ground contact on the fuel injector at a second axial distance from the fuel injector end surface along the fuel injector central longitudinal axis. The first axial distance may be less than the second axial distance, greater than the second axial distance, or approximately equal to the second axial distance. The method may further include the step of providing the fuel injector with an electrical environmental seal for preventing contamination of the positive and ground contacts of the electrical bus and the fuel injector upon connection thereof with the fuel injector positive and ground contacts. 
     Additional features, advantages, and embodiments of the invention may be set forth or apparent from consideration of the following detailed description, drawings, and claims. Moreover, it is to be understood that both the foregoing summary of the invention and the following detailed description are exemplary and intended to provide further explanation with out limiting the scope of the invention as claimed. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate preferred embodiments of the invention and together with the detail description serve to explain the principles of the invention. In the drawings: 
     FIG. 1 is an illustrative front view of a fuel injection system according to the present invention, including a first embodiment of a fuel injector for installation to a fuel delivery tube; 
     FIG. 2 is an illustrative perspective view of a second embodiment of the fuel injection system according to the present invention; 
     FIG. 3A is an illustrative perspective view of the fuel injection system according to the present invention, illustrating fuel injectors, a fuel delivery tube and an electrical bus in an assembled configuration; 
     FIG. 3B is an exploded perspective view of the fuel injection system of FIG. 3A, illustrating fuel injectors, the fuel delivery tube and the electrical bus in a disassembled configuration; and 
     FIG. 4 is an illustrative view of electrical wires which connect the positive and ground contacts in the electrical bus to a generally single connection point. 
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings wherein like reference numerals designate corresponding parts throughout the several views, FIGS. 1,  3 A and  3 B illustrate a first embodiment of an integrated fuel delivery and electrical connection system, generally designated fuel injection system  10 . Fuel injection system  10  may generally include a fuel delivery tube  12 , an electrical bus  14  and a plurality of fuel injectors  16 . 
     Fuel delivery tube  12  may include an opening  18  for insertion of a fuel tube  22 . A plurality of circular openings  13  may be provided in fuel delivery tube  12  for insertion of a top portion  17  of fuel injectors  16  therein, as illustrated in FIG.  1 . Openings  13  may be dimensioned to provide a resist-fit between fuel injectors  16  and fuel delivery tube  12 . 
     A plurality of openings  24  may likewise be formed in electrical bus  14  for insertion and connection of fuel injectors  16 , as also illustrated in FIG.  1 . Openings  24  may be dimensioned to provide a resist-fit between fuel injectors  16  and electrical bus  14 . Electrical bus  14  may further include a plurality of positive electrical contacts  26  for electrical connection to a respective fuel injector positive electrical contact  28  (described in greater detail below), and a generally single ground contact  32  for electrical connection to a fuel injector ground contact  34  (described in greater detail below). It should be understood that the location of positive and ground contacts  26 ,  28  and  32 ,  34  on electrical bus  14  and fuel injectors  16 , respectively, may be reversed from the embodiment illustrated in FIG. 1, as would be apparent to a skilled artisan. An upper electrical environmental seal  36  may be provided in electrical bus  14  for preventing contamination of positive and ground contacts  26 ,  32  in electrical bus  14  upon connection thereof with positive and ground contacts  32 ,  34  on fuel injector  16 . 
     Referring to FIGS. 3B and 4, a plurality of electrical wires  38  may be connected at one end thereof to respective positive and ground contacts  26 ,  32  and terminate at a generally single connection point  42  on electrical bus  14 . The electrical bus configuration illustrated in FIGS. 3B and 4, includes a plurality of common ground contacts  32  and a plurality of electrical wires  38  leading from ground contacts  32  to connection point  42 . Alternatively, it should be understood that a single axially extending ground contact  32  could be employed to achieve the same results. Since the ground connection is common throughout the electrical bus  14 , it is apparent that the total number of connection terminals  43  at connection point  42  would be the number of fuel injectors plus one. An electrical supply wire (not shown) having a female connector for insertion of male connection terminals  43  may be connected at connection point  42  to provide electricity for fuel injectors  16 . It is apparent that connection point  42  may instead be provided with female connections for insertion of male connections of an electrical supply wire. 
     Electrical bus  14  may include a plurality of conventional connectors (not shown), such as conventional male/female connectors, for connection thereof to fuel delivery tube  12 . Alternatively, since electrical bus  14  is disposed between fuel injector  16  and fuel delivery tube  12 , electrical bus  14  may be connected with fuel delivery tube  12  by means of the connection of fuel injectors  16  to fuel delivery tube  12 . Electrical bus  14  may be fabricated from a conventional non-conductive material such as plastic or the like. 
     Referring next to FIG. 1, fuel injector positive and ground contacts  28  and  34 , respectively, may be spatially disposed along a fuel injector central longitudinal axis-A to prevent an electrical short therebetween. Likewise positive and ground contacts  26  and  32  may be disposed at predetermined radial locations from a central longitudinal axis-B of electrical bus  14 . A lower electrical environmental seal  44  may be provided on fuel injector  16  for preventing contamination of positive and ground contacts  26 ,  28  in electrical bus  14  upon connection thereof with positive and ground contacts  28 ,  34  on fuel injector  16 . A fuel seal o-ring  46  may also be provided adjacent an upper surface of fuel injector  16  for sealing the contact between fuel injector  16  and fuel delivery tube  12 . 
     Referring next to FIG. 2, a second embodiment of a fuel injector  48  according to the present invention is illustrated. For the embodiment of FIG. 2, instead of the positive and ground contacts  28 ,  34  being axially spaced as illustrated in the fuel injector configuration for FIG. 1, positive and ground contacts  52 ,  54  for the second embodiment are each disposed at a predetermined location along the central longitudinal axis-A of fuel injector  48 . Moreover, positive and ground contacts  52 ,  54  are disposed at opposite surfaces along the circumference of fuel injector  48  at the predetermined axial location. A fuel seal o-ring  46  may also be provided adjacent an upper surface of fuel injector  48  for sealing the contact between fuel injector  48  and fuel delivery tube  12 . For the second embodiment of fuel injector  48 , it is apparent that the positive contacts  26  in electrical bus  14  could be located adjacent fuel injector positive contacts  52  and the ground contacts  32  could be located adjacent fuel injector ground contact  54 . 
     An exemplary method for installing and testing fuel injection system  10  will now be described in detail. 
     In order to install fuel injection system  10  onto an automobile engine, first, one or more fuel injectors  16  (or  48 ) may be inserted into designated openings  24  in electrical bus  14 . Electrical bus  14  may then be connected to fuel delivery tube  12  by means of separate connectors (as discussed above) or by insertion of fuel injector  16  (or  48 ) into the respective openings  13  in fuel delivery tube  12 . The fuel injection system  10  including fuel delivery tube  12 , electrical bus  14  and fuel injectors  16  (or  48 ) may then be mounted onto an engine as necessary. Lastly, as discussed above, an electrical supply wire (not shown) having a female connector may be connected at connection point  42  to provide electricity for fuel injectors  16  (or  48 ). 
     In order to test fuel injection system  10  before installation onto an automobile engine, a fuel supply may be connected to fuel tube  22  and an electrical supply wire (not shown) having a female connector may be connected at connection point  42  to provide electricity for fuel injectors  16  (or  48 ). The fuel injection system  10  including fuel delivery tube  12 , electrical bus  14  and fuel injectors  16  (or  48 ) may then be tested as necessary before mounting onto an engine. 
     It is apparent from the above discussion that the components of fuel injection system  10 , which generally include fuel delivery tube  12 , electrical bus  14  and a plurality of fuel injectors  16 , may be used in a variety of combinations. For example, electrical bus  14  may be used in a standalone manner and not integrated into fuel delivery tube  12  (i.e. the embodiment shown in FIG.  3 B). Alternatively, electrical bus  14  may be fabricated with fuel delivery tube  12  as a single unit, and fuel injectors  16  (or  48 ) may be separately installed on the unit and thereafter installed onto an automobile engine. Yet in a further combination, electrical bus  14 , fuel delivery tube  12  and fuel injectors  16  (or  48 ) may be fabricated as separate components of an assembly, and thereafter assembled to form an integrated package for installation onto an automobile engine. 
     Although particular embodiments of the invention have been described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those particular embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.