Abstract:
A fuel rail assembly configured for coupling to an engine, the fuel rail including a body having therein a fuel passageway, and a fuel injector coupled to the body and in fluid communication with the fuel passageway. A portion of the body is configured to interconnect with the engine assembly to secure the fuel rail assembly to the engine without using conventional threaded fasteners.

Description:
FIELD OF THE INVENTION 
   The invention relates to fuel rail assemblies for the fuel system of an internal combustion engine. 
   BACKGROUND OF THE INVENTION 
   Generally, a fuel rail supplies fuel to multiple fuel injectors that inject fuel into the intake manifold of an engine. Conventionally, the inlet ends of the fuel injectors are removably secured to the fuel rail using clips or other similar mechanical attachment means. The outlet ends of the fuel injectors typically engage corresponding openings or ports in the intake manifold. The conventional fuel rail typically includes at least one flange shaped to engage with the intake manifold once the fuel injectors are positioned in the respective manifold ports, such that a conventional fastener (e.g., a bolt or sheet metal screw) may secure the flange to the intake manifold, thereby securing the fuel rail and the fuel injectors to the intake manifold. 
   SUMMARY OF THE INVENTION 
   The present invention provides an improved fuel rail assembly that does not require the use of conventional threaded fasteners to secure the fuel rail and fuel injectors to the intake manifold. By eliminating the use of conventional threaded fasteners, the number of parts and the cost and time for assembly are reduced. 
   The fuel rail assembly of the present invention generally provides an improved connection configuration with the intake manifold. The improved connection configuration is facilitated, in part, by the construction of the fuel rail assembly, which is similar to the fuel rail assembly disclosed in U.S. patent application Ser. No. 09/981,223 filed on Oct. 17, 2001 and assigned to the Robert Bosch Corporation, the entire contents of which is incorporated herein by reference. 
   More specifically, the present invention provides a fuel rail assembly configured for coupling to an engine, the fuel rail assembly including a body having therein a fuel passageway, and a fuel injector coupled to the body and in fluid communication with the fuel passageway. A portion of the body is configured to interconnect with the engine assembly to secure the fuel rail assembly to the engine without using conventional threaded fasteners. 
   The present invention also provides an engine assembly including a fuel rail assembly having a body including therein a fuel passageway, and a fuel injector coupled to the body and in fluid communication with the fuel passageway. The engine assembly also includes an engine having an opening to receive the fuel injector therein. At least a portion of the body is interconnected with the engine such that the body is secured to the engine without using conventional threaded fasteners. 
   Further, the present invention provides a method of installing a fuel rail assembly onto an intake manifold of an internal combustion engine, the intake manifold having a receiving portion. The method includes providing a fuel rail assembly including a body having therein a fuel passageway, and at least one fuel injector coupled to the body and in fluid communication with the fuel passageway, a portion of the body defining a fastening member. The method also includes aligning the fastening member with the receiving portion of the intake manifold, and interconnecting the fastening member with the receiving portion to secure the fuel rail assembly to the intake manifold without conventional threaded fasteners. 
   Other features and aspects of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims, and drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a partial perspective view of one construction of a fuel rail assembly embodying the present invention, illustrating one construction of a connector assembly connecting the fuel rail assembly with a portion of an engine. 
       FIG. 2  is a frontal partial cutaway view of the connector assembly. 
       FIG. 3  is a section view of the connector assembly taken along line  3 — 3  of  FIG. 2 . 
       FIG. 4  is a frontal partial cutaway view of another construction of the fuel rail assembly embodying the present invention, illustrating another construction of the connector assembly connecting the fuel rail assembly with a portion of the engine. 
       FIG. 5  is a frontal exploded view of the connector assembly of  FIG. 4 . 
       FIG. 6  is a frontal partial cutaway view of yet another construction of the fuel rail assembly embodying the present invention, illustrating yet another construction of the connector assembly connecting the fuel rail assembly with a portion of the engine. 
       FIG. 7  is a frontal exploded view of the connector assembly of  FIG. 6 . 
   

   Before one embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. 
   DETAILED DESCRIPTION 
   With reference to  FIG. 1 , one construction of a fuel rail assembly  10  embodying the present invention is shown. The fuel rail assembly  10  is shown in relation to a portion of an engine defining an intake manifold  14 . For purposes of clarity, only a portion of the fuel rail assembly  10  and the intake manifold  14  is shown. Also, it should be known that the fuel rail assembly  10  is not limited for use in any particular engine configuration, and can be used with engine configurations other than the configuration partially illustrated in  FIG. 1 . 
     FIG. 1  illustrates an intake manifold  14  used in a V-8 engine configuration, including two banks, each bank including four fuel injectors  18  feeding four respective cylinders (not shown). Also, for purposes of clarity, only one bank of fuel injectors  18  is partially shown in  FIG. 1 . In one construction of the present invention, the body  22  includes a fuel rail  30  having therein a fuel passageway  26 , and an overmolding  34  that substantially covers or encloses the fuel rail  30 . In this construction, the fuel injectors  18  are coupled to the fuel rail  30 , such that the fuel injectors  18  are fluidly connected with the fuel passageway  26 . In such a construction, the fuel rail  30  is preferably made of metal, while the overmolding  34  is preferably formed from plastic to enclose the fuel rail  30  in a conventional overmolding process. Alternatively, the fuel rail  30  may also be formed from plastic. Also, a portion of the overmolding  34 , or fuel injector overmold  38 , covers or encloses a portion of each fuel injector  18 , such that the interface between the fuel rail  30  and each fuel injector  18  is covered by the fuel injector overmold  38 . Therefore, any fuel potentially leaking between the fuel rail  30  and the fuel injector  18  is prevented from escaping the fuel rail assembly  10 . As a result, undesirable evaporative emissions from the fuel rail assembly  10  are decreased. 
   Alternatively, in another construction of the fuel rail assembly  10 , the fuel rail assembly  10  may include a body  22  defining a fuel passageway  26  therein. The fuel injectors  18  may couple to the body  22  and fluidly communicate with the fuel passageway  26 , such that fuel from a fuel source (not shown) is delivered to the fuel injectors  18  via the fuel passageway  26 . In such a construction, the body  22  may be formed as a singular piece of molded plastic and include portions which cover or enclose a portion of each fuel injector  18 . 
   As shown in  FIG. 1 , the fuel injectors  18  are inserted into engine openings in the form of fuel injector cups  42  defined in the intake manifold  14 . While positioned in the fuel injector cups  42 , each fuel injector  18  is aligned with an intake runner (in the cylinder head portion of the engine, not shown) to supply a mixture of air and fuel to an associated cylinder. In the construction illustrated in  FIG. 1 , a connector assembly  46  is shown to releasably secure the body  22 , and therefore the fuel rail assembly  10 , to the intake manifold  14 . The fuel injectors  18  are maintained within their respective fuel injector cups  42  by the connector assembly  46 . The connector assembly  46  includes a first part in the form of a fuel rail post  50  extending away from the body  22  and toward the intake manifold  14 . In the illustrated construction of  FIG. 1 , the fuel rail post  50  is integrally formed with the overmolding  34 . However, the fuel rail post  50  may also be a separate component coupled to the overmolding  34  in another construction of the fuel rail assembly  10 . 
   The connector assembly  46  also includes a second part in the form of an intake manifold post  54  extending away from the intake manifold  14  and toward the body  22 . In the illustrated construction of  FIG. 1 , the intake manifold post  54  is integrally formed with the intake manifold  14 . However, the intake manifold post  54  may also be a separate component coupled to the intake manifold  14  in another construction of the fuel rail assembly  10 . 
   The intake manifold post  54  includes an opening  58  to receive the fuel rail post  50  therein. Although the connector assembly  46  is shown spaced from the fuel injectors  18  and positioned between adjacent fuel injectors  18  in  FIG. 1 , many different configurations and placements of the connector assemblies  46  are possible and fall within the spirit and scope of the present invention. For example, one or more connector assemblies  46  may be used per bank of fuel injectors  18  to secure the fuel rail assembly  10  to the intake manifold  14 . In the illustrated construction of  FIG. 1 , in which four fuel injectors  18  comprise each bank of fuel injectors  18 , connector assemblies  46  may be utilized, among other locations, between the first and second fuel injectors  18  and the third and fourth fuel injectors  18 , between the first and second, second and third, and third and fourth fuel injectors  18 , or solely between the second and third fuel injectors  18 . 
   The connector assembly  46  also includes a locking mechanism in the form of a snap-fit mechanism, more specifically a resilient tab  62 , which is integrally formed with the fuel rail post  50 . Upon assembling the fuel rail assembly  10  and the intake manifold  14 , the fuel rail post  50  is inserted into the opening  58  of the intake manifold post  54 , thereby causing the resilient tab  62  to initially deflect as it enters the opening  58 . An aperture  66  is formed in a side wall  70  of the intake manifold post  54  to allow the resilient tab  62  to “snap back” to its undeflected shape into the aperture  66 , thus interlocking the fuel rail post  50  and the intake manifold post  54 . The resilient tab  62  includes a shoulder  72  which abuts an upper edge  73  of the aperture  66  to substantially prevent withdrawal of the fuel rail post  50  from the intake manifold post  54 . The resilient tab  62  and the aperture  66  may be formed on any side of their respective posts  50 ,  54  such that the resilient tab  62  and aperture  66  are aligned upon assembly of the fuel rail assembly  10  and the intake manifold  14 . To unlock and disassemble the fuel rail assembly  10  from the intake manifold  14 , the resilient tab  62  is pushed back to its deflected shape so the shoulder  72  disengages the upper edge  73  of the aperture  66 . This permits the fuel rail post  50  to be disengaged and withdrawn from the intake manifold post  54 . 
   As shown in  FIG. 2 , the intake manifold post  54  includes a tapered interior surface  74 . Upon insertion into the intake manifold post  54 , a distal end  76  of the fuel rail post  50  frictionally engages the tapered interior surface  74  before the resilient tab  62  snaps into the aperture  66 , during which time the distal end  76  of the fuel rail post  50  and the portion of the tapered interior surface  74  in frictional engagement with the distal end  76  elastically deform. After the distal end  76  of the fuel rail post  50  and the portion of the tapered interior surface  74  elastically deform to an extent allowing the fuel rail post  50  to be inserted sufficiently far enough into the intake manifold post  54 , the resilient tab  62  snaps into the aperture  66 , therefore interlocking the fuel rail post  50  and the intake manifold post  54 . After the resilient tab  62  snaps into the aperture  66 , the previously-elastically deformed distal end  76  and frictionally engaged portion of the tapered interior surface  74  are allowed to recover to their undeformed or substantially undeformed shapes, thereby tending to bias the fuel rail post  50  out of the intake manifold post  54  (upward in  FIG. 2 ). In other words, the tapered interior surface  74  of the intake manifold post  54  tends to urge the fuel rail post  50  toward disengagement with the intake manifold post  54  when the distal end  76  of the fuel rail post  50  frictionally engages the tapered interior surface  74  of the intake manifold post  54 . As a result, the shoulder  72  of the resilient tab  62  is maintained in tight abutment (see  FIG. 3 ) with the upper edge  73  of the aperture  66 , thereby substantially preventing unwanted or accidental unlocking of the posts  50 ,  54 . 
   In another configuration of the connector assembly (not shown), the configurations of the fuel rail and intake manifold posts may be reversed, such that the fuel rail post includes the opening to receive therein the intake manifold post, and the intake manifold post includes the resilient tab, which engages an aperture in the fuel rail post to interlock the posts. Also, in yet another configuration of the connector assembly (not shown), a singular post extending from one of the body and the intake manifold may be inserted into a corresponding opening not otherwise defined in a post-like member formed in the other of the body and the intake manifold. Further, the resilient tab may be formed with the post, and the aperture (or a recess) may be formed in the opening to accept the resilient tab. Those skilled in the art will also recognize that the illustrated tab-and-aperture locking mechanism is only one type of suitable locking mechanism, and that other types could be substituted. Such other types of locking mechanisms may include, among others, spring-loaded detent mechanisms, latch mechanisms, and snap-fit mechanisms. 
     FIGS. 4–5  illustrate another construction of a fuel rail assembly  78  embodying the present invention. Like the fuel rail assembly  10 , the fuel rail assembly  78  is shown in relation to a portion of an engine defining an intake manifold  82 . Also, like the fuel rail assembly  10 , only a portion of the fuel rail assembly  78  is shown for purposes of clarity. In one construction of the present invention, the fuel rail assembly includes a body  86  having a fuel rail  92  therein. The fuel rail  92  includes therein the fuel passageway  88 , and an overmolding  98  substantially covers or encloses the fuel rail  92 . In this construction, fuel injectors  100  are coupled to the fuel rail  92 , such that the fuel injectors  100  are fluidly connected with the fuel passageway  88 . In such a construction, the fuel rail  92  is preferably made of metal, while the overmolding  98  is preferably formed from plastic to enclose the fuel rail  92  in a conventional overmolding process. Alternatively, the fuel rail  92  may also be formed from plastic. Also, a portion of the overmolding  98 , or fuel injector overmold  101 , covers or encloses a portion of each fuel injector  100 , such that the interface between the fuel rail  92  and each fuel injector  100  is covered by the fuel injector overmold  101 . 
   Alternatively, in another construction, the fuel rail assembly  78  includes a body  86  defining a fuel passageway  88  therein. Fuel injectors  100  are coupled to the body  86  and fluidly communicate with the fuel passageway  88 , such that fuel from a fuel source (not shown) is delivered to the fuel injectors  100  via the fuel passageway  88 . In such a construction, the body  86  is preferably formed as a singular piece of molded plastic and include portions which cover or enclose a portion of each fuel injector  100 . 
   The fuel injectors  100  are inserted into engine openings in the form of fuel injector cups  102  defined in the intake manifold  82 . The fuel injector cups  102  are shaped having a stepped opening, such that lips  106  are formed in the upper ends of the cups  102  (as shown in  FIGS. 4–5 ). As shown in  FIG. 4 , a connector assembly  110  is utilized to secure the fuel rail assembly  78  to the intake manifold  82 . A first part of the connector assembly  110  is defined by the configuration of the fuel injector overmold  101 . The connector assembly  110  also includes a second part defined by the fuel injector cups  102 , each of which includes a lip  106 , such that each fuel injector overmold  101  is inserted into a respective fuel injector cup  102 . 
   Although only a singular connector assembly  110  is shown in  FIGS. 4–5  in conjunction with a singular fuel injector  100 , many different configurations and placements of the connector assembly  110  are possible and fall within the spirit and scope of the present invention. For example, connector assemblies  110  may be only utilized on one, some, or all the fuel injectors  101  in a particular bank of fuel injectors  101  to secure the fuel rail assembly  78  to the intake manifold  82 . 
   The connector assembly  110  also includes a locking mechanism in the form of a snap-fit mechanism, more specifically multiple resilient tabs  118 , which are integrally formed with the fuel injector overmold  101 . Upon assembling the fuel rail assembly  78  and the intake manifold  82 , each fuel injector overmold  101  is inserted into its associated fuel injector cup  102 , thereby causing the resilient tabs  118  to initially deflect as they contact the lip  106 . As the resilient tabs  118  pass by the lip  106 , the resilient tabs  118  “snap back” to their undeflected shapes, thus interlocking the fuel injector overmold  101  and the fuel injector cup  102 . As shown in  FIGS. 4–5 , a retainer clip  122  is engaged with a shoulder  124  formed in the fuel injector overmold  101  to act as a spacer, thus maintaining the resilient tabs  118  in abutment with an inside shoulder  123  of the lip  106  to substantially prevent unwanted or accidental movement of the fuel injector  100  in the injector cup  102 . 
   A seal  126  in the form of an o-ring is provided around the fuel injector overmold  101  in a groove  130  formed in the fuel injector overmold  101 . The seal  126  substantially prevents leakage through a gap between the fuel injector overmold  101  and the lip  106 . The seal  126  is supported in the groove  130  by the resilient tabs  118  in such a fashion to pre-load the seal  126 . By doing this, the seal  126  is substantially prevented from moving around or displacing during insertion of the fuel injector overmold  101  into the fuel injector cup  102 . During assembly of the fuel rail assembly  78 , the seal  126  may be stretched over the resilient tabs  118  before finally being positioned in the groove  130 . 
     FIGS. 6–7  illustrate yet another construction of a fuel rail assembly  134  embodying the present invention. The fuel rail assembly  134  is substantially the same as the fuel rail assembly  78  of  FIGS. 4–5 , with the exception that a shoulder ( 124  in  FIGS. 4–5 ) is not used in combination with a retainer clip ( 122  in  FIGS. 4–5 ) to support the fuel rail assembly in the engine. 
   Fuel injectors  138  are inserted into engine openings in the form of fuel injector cups  142  defined in an intake manifold  146 . The fuel injector cups  142  are shaped having a stepped opening, such that a lip  150  is formed in the upper end of each cup  142  (as shown in  FIGS. 6–7 ). As shown in  FIG. 6 , a connector assembly  154  is utilized to secure the fuel rail assembly  134  to the intake manifold  146 . A first part of the connector assembly  154  is defined by the configuration of a fuel injector overmold  162  at least partially covering or enclosing each fuel injector  138 . The connector assembly  110  also includes a second part defined by the fuel injector cups  142 , each of which includes a lip  150 , such that each fuel injector overmold  162  is inserted into a respective fuel injector cup  142 . 
   The connector assembly  154  also includes a locking mechanism in the form of a snap-fit mechanism, more specifically multiple resilient tabs  166 , which are integrally formed with each fuel injector overmold  162 . Upon assembling the fuel rail assembly  134  and the intake manifold  146 , each fuel injector overmold  162  is inserted into its associated fuel injector cup  142 , thereby causing the resilient tabs  166  to initially deflect as they contact the lip  150 . As the resilient tabs  166  pass by an inside shoulder  168 , the resilient tabs  166  “snap back” to their undeflected shapes, thus interlocking the fuel injector overmold  162  and the fuel injector cup  142 . 
   The injector cup  142  includes a tapered interior surface  170 , such that lower portions of the resilient tabs  166  frictionally engage the tapered interior surface  170  in much the same way as the fuel rail post  50  engages the tapered interior surface  74  of the intake manifold post  54 . Upon insertion into the injector cup  142 , the lower portions (in  FIG. 6 ) of the resilient tabs  166  frictionally engage the tapered interior surface  170  before the upper portions of the resilient tabs  166  snap back to their undeflected shapes after passing by the inside shoulder  168  of the lip  150 , during which time the lower portions of the tabs  166  frictionally engaging the tapered interior surface  170  elastically deform. After passing by the inside shoulder  168 , the upper portions of the resilient tabs  166  recover to their undeflected shapes, therefore interlocking the fuel injector overmold  162  and the injector cup  142 . Upon completing the insertion of the fuel injector overmold  162  into the injector cup  142 , the elastically deformed lower portions of the tabs  166  are allowed to recover to their undeformed or substantially undeformed shapes thereby tending to bias the fuel injector overmold  101  out of the fuel injector cup  142  (upward in  FIG. 6 ). In other words, the tapered interior surface  170  of the injector cup  142  tends to urge the fuel injector overmold  101  toward disengagement with the fuel injector cup  142  when the lower portions of the resilient tabs  166  frictionally engage the tapered interior surface  170  of the fuel injector cup  142 . As a result, the resilient tabs  166  are maintained in tight abutment (see  FIG. 6 ) with the inside shoulder  168  of the lip  150 , thereby substantially preventing unwanted or accidental movement of the fuel injector  138  in the injector cup  142 . 
   Like the fuel rail assembly  78 , the fuel rail assembly  134  includes a seal  174  in the form of an o-ring around the fuel injector overmold  162  in a groove  178  formed in the fuel injector overmold  162 . The seal  174  substantially prevents leakage through a gap between the fuel injector overmold  162  and the lip  150 . The seal  174  is supported in the groove  178  by the resilient tabs  166  in such a fashion to pre-load the seal  174 . By doing this, the seal  174  is substantially prevented from moving around or displacing during insertion of the fuel injector overmold  162  into the fuel injector cup  142 . During assembly of the fuel rail assembly  134 , the seal  174  may be stretched over the resilient tabs  166  before finally being positioned in the groove  178 . 
   Although only a singular connector assembly  154  is shown in conjunction with a singular fuel injector  138 , many different configurations and placements of the connector assembly  154  are possible and fall within the spirit and scope of the present invention. For example, connector assemblies  154  may be utilized on one, some, or all the fuel injectors  138  in a particular bank of fuel injectors  138  to secure the fuel rail assembly  134  to the intake manifold  146 .