Abstract:
Attaching a fuel injector to a common rail may utilize a fuel injector and an integral tab that has a solid head portion from which a first flexible prong and a second flexible prong protrude and define a gap therebetween. A fuel injector cup may define a notch through which the first prong and the second prong reside to secure the fuel injector to the fuel injector cup, which is attached to the rail. A first prong interior straight wall surface and a second prong interior straight wall surface may face the gap and be parallel. The prongs may define entry contact surfaces and exit contact surfaces that meet at prescribed angles to aid in insertion and hinder retraction of the injector tab from the injector cup. The tab defines a solid head portion below the gap that resides in the notch.

Description:
FIELD 
     The present disclosure relates to a structure to aid in orientation and retention of a fuel injector to a fuel rail. 
     BACKGROUND 
     This section provides background information related to the present disclosure which is not necessarily prior art. Internal combustion engines such as direct injection engines may employ fuel injectors that provide a fluid conduit between a pressurized fuel rail and a combustion cylinder of an internal combustion engine. While current fuel injectors and corresponding fuel rails have been satisfactory for their given applications, such components are not without need for improvement. 
     Engine assemblers desire a tight, secure and aligned assembly of the fuel injector to the fuel rail to prevent disassembly during part shipment and during installation of the fuel rail and fuel injectors onto the engine. Additionally, prevention of a fuel injector from becoming misaligned with the fuel rail during assembly onto an engine or prior to assembly onto an engine or during engine operation is also desired. Typically, a fuel rail will employ a fuel injector cup that is brazed, welded or otherwise secured to a fuel rail. An injector may reside within the injector cup with the aid of a compressed O-ring, which resides over the injector inlet. During shipment of fuel injectors or during assembly of a fuel rail and an injector combination onto an engine, because only an O-ring is compressed against an interior of the injector cup, the integrity of the holding force of the compressed O-ring may be compromised, resulting in parting of the injector from the injector cup or misalignment of the parts prior to installation onto an engine. Moreover, during operation, fuel injectors may become stuck or seized onto the engine cylinder head due to soot or carbon build-up at the tip of the injector. In such a case, it is desirable to have the rail and injector separate easily. Thus, during servicing of a fuel injection system, service technicians desire a relatively quick disconnect of the fuel injector from adjacent components. 
     What is needed then is a device that quickly permits alignment and secure connection of a fuel injector with an injector cup and injector rail but that also permits quick and easy separation of the fuel injector from an injector cup. 
     SUMMARY 
     This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. An apparatus to secure a fuel injector to an engine&#39;s common fuel rail may employ a fuel injector, a fuel injector cup, and an orientation tab integral with the fuel injector. The tab may attach to the fuel injector cup to secure the fuel injector to the fuel injector cup, which is brazed or welded to the common fuel rail. The fuel injector cup may further define a flange that defines a notch with the tab protruding through the notch to secure the fuel injector to the fuel injector cup. Upon securing the tab, the fuel injector also becomes aligned with the fuel rail, which may be attached to the fuel injector cup. The tab may employ a flexible first prong and a flexible second prong such that the first prong and the second prong protrude through the notch to secure the tab to the flange. The first prong and the second prong define a gap therebetween. The first prong may further exhibit a first prong interior straight wall surface that faces the gap and the second prong may further exhibit a second prong interior straight wall surface that faces the gap. The first prong interior straight wall surface and the second prong interior straight wall surface may be parallel. The first prong may also exhibit a first entry contact surface and a first exit contact surface that meet to form an apex, and the second prong may further exhibit a second entry contact surface and a second exit contact surface that meet to form an apex. 
     The tab may define a solid head portion below the gap, the solid head portion may be bounded by a first outside wall with a surface and a second outside wall with a surface; the surfaces may be parallel. The solid head portion may reside in the notch such that only a solid portion of head portion resides in the notch; this eliminates flexing of the head and prongs when bounding parallel walls of the solid head portion contact structure defining the notch. The first entry contact surface and the first prong interior straight wall surface form a first angle that is less than a second angle formed by the first exit contact surface (extended) and the first sidewall surface of the first outside wall. 
     Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
         FIG. 1  is a side view of a vehicle depicting, in phantom, portions of a fuel system; 
         FIG. 2  is a schematic of a vehicle fuel supply system depicting fuel injectors, a fuel injection pump and a fuel pump module within a fuel tank; 
         FIG. 3  is a perspective view of a fuel injector, a fuel injector cup, a fuel injector spring tab, and a fuel injector alignment tab in accordance with the present disclosure; 
         FIG. 4  is a side view of a fuel injector, a fuel injector cup, a fuel injector spring tab, and a fuel injector alignment tab in accordance with the present disclosure; 
         FIG. 5  is a side view of a fuel injector with a fuel injector tab in accordance with the present disclosure; 
         FIG. 6  is a side view of the fuel injector cup in accordance with the present disclosure; 
         FIG. 7  is a top view of the fuel injector cup in accordance with the present disclosure; 
         FIG. 8  is a is a cross-sectional view of the fuel injector alignment tab in accordance with the present disclosure; 
         FIG. 9  is a side view of the fuel injector with a fuel injector alignment tab in accordance with the present disclosure; 
         FIG. 10  is a cross sectional view of the fuel injector, fuel injector cup and fuel injector alignment tab in accordance with the present disclosure; 
         FIG. 11  is a cross sectional view of the fuel injector alignment tab relative to the fuel injector cup; 
         FIG. 12  is a cross sectional view of the fuel injector, fuel injector cup and fuel injector alignment tab in accordance with the present disclosure; 
         FIG. 13  is a cross sectional view of the fuel injector alignment tab relative to the fuel injector cup; 
         FIG. 14  is a cross sectional view of the fuel injector, fuel injector cup and fuel injector alignment tab in accordance with the present disclosure; 
         FIG. 15  is a cross sectional view of the fuel injector alignment tab relative to the fuel injector cup; 
         FIG. 16  is a cross sectional view of the fuel injector, fuel injector cup and fuel injector alignment tab in accordance with the present disclosure; and 
         FIG. 17  is a cross sectional view of the fuel injector alignment tab relative to the fuel injector cup. 
     
    
    
     Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully with reference to the accompanying drawings. The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. When an element or layer is referred to as being “on”, “engaged to”, “connected to” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to”, “directly connected to” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     Spatially relative terms, such as “inner,” “outer,” “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     With reference to  FIGS. 1-17 , a device that retains a fuel injector to a fuel injector cup and aligns a fuel injector to a fuel rail will be disclosed.  FIG. 1  depicts a vehicle  10 , such as an automobile, having an engine  12 , a fuel supply line  14 , a fuel tank  16 , and a fuel pump module  18 . Fuel pump module  18  resides within fuel tank  16  and may be submerged in or surrounded by varying volumes of liquid fuel when fuel tank  16  possesses liquid fuel. For purposes of explanation of the present disclosure, the liquid fuel may be considered gasoline since the present disclosure will be explained in the context of a fuel supply system  20  that employs a fuel injection pump  22 , which may be employed to pressurize fuel rail  24  of engine  12 . However, it is to be understood that the present disclosure may be adaptable to a vehicle employing diesel, or other liquid fuel. Fuel pump module  18  may be employed to supply liquid fuel to engine  12  through fuel supply line  14 .  FIG. 2  depicts fuel supply system  20  in which one or more fuel injectors  26  may be installed in engine  12  to receive fuel from a fuel injector common rail  24 . Fuel supply system  20  may be either a return or a returnless fuel system. To reach a fuel pressure that is high enough to increase the efficiency of combustion, fuel may be pressurized by a fuel injection pump  22  before fuel reaches common rail  24 . To ensure that fuel is clean enough to pass through fuel injection pump  22  and then fuel injectors  26 , fuel may pass through a fuel filter  28  resident in fuel supply line  14 . 
     Before continuing with a description of the present teachings, the primary focus will be on a single fuel injector, a single fuel injector cup, and a single fuel injector alignment tab because each fuel injector  26  in an engine  12  with multiple fuel injectors  26  may have the same arrangement or structure. Turning now to  FIG. 3 , an enlarged perspective view of fuel injector  26  is depicted along with an injector cup. 
     Continuing,  FIGS. 3 and 4  depict a side view of a fuel injector assembly  30 , which may include fuel injector  26 , a fuel injector spring tab  32 , a fuel injector alignment tab  34  and a fuel injector cup  36 . An electrical plug  38  is a part of fuel injector  26  and provides a location where an electrical connection from a vehicle wiring harness interfaces with fuel injector  26 . As depicted, fuel injector spring tab  32  may have a first spring prong  40  and a second spring prong  42  that each reside around a side of fuel injector  26 . Spring prongs  40 ,  42  are flexible and move in an upward and downward motion that is parallel to an axis of fuel injector  26 . First spring prong  40  has a first top surface  44  while second spring prong  42  has a second top surface  46  such that top surfaces  44 ,  46  provide a surface for fuel injector cup  36  or a flange  68  of fuel injector cup  36  to contact and bias prongs  40 ,  42 . A spring tab base  48  also has a first base prong  50  and a second base prong  52  that reside on opposing sides of fuel injector  26  to clamp to fuel injector  26  and form a press fit or interference fit with fuel injector  26 . 
     Turning to  FIG. 5 , fuel injector  26  is depicted equipped with fuel injector alignment tab  34 , parallel to a longitudinal axis  70  of fuel injector  26 . Secured over injector inlet  56  of fuel injector  26  is an O-ring  58 . Before proceeding with additional structural details of fuel injector assembly  30 , potential construction materials of the various parts of fuel injector assembly  30  will be discussed. Fuel injector  26 , fuel injector spring tab  32  and fuel injector cup  36  may be made of stainless steel, while electrical plug  38  and fuel injector alignment tab  34  may be made of a heat resistant plastic, for example, while O-ring  58  may be made of a heat resistant rubber.  FIG. 5  also depicts a gap  60  that is located between and defined by fuel injector alignment tab  34  and body  62  of fuel injector  26 . Gap  60  exists for insertion of a sidewall of fuel injector cup  36 , as will be explained later. 
       FIGS. 6 and 7  depict views of fuel injector cup  36  which is a cover having an open end  64  and a rounded end  66  that is open to a lesser degree. Rounded end  66  has a hole through which fuel is received from fuel rail  24  before such fuel passes into fuel injector  26 . Fuel injector cup  36  may have a flange  68  that may protrude at ninety degrees from a longitudinal axis  70  of fuel injector cup  36 . Longitudinal axis  70  may be common to fuel injector  26  and fuel injector cup  36 . Fuel injector cup  36  may be hollow to accommodate fuel injector inlet  56  and O-ring  58 , which may be located around injector inlet  56 . As depicted in  FIG. 7 , flange  68  may define a notch  74  for part of a depth of flange  68  or an entire depth of flange  68  to permit unobstructed access directly to sidewall  72  of fuel injector cup  36 . 
     Turning now to  FIG. 8 , enlarged cross-sectional view of fuel injector alignment tab  34  depicts an alignment tab column  76  protruding from body  62  of fuel injector  26 . In cross section, alignment tab column  76  widens to a tab head  78  that defines a first alignment tab prong  80  and a second alignment tab prong  82 . Between first alignment tab prong  80  and second alignment tab prong  82 , a prong gap  84  is defined. Alignment tab prongs  80 ,  82  are mirror images of each other and each exhibits a retention feature that operates in conjunction with flange  68  of fuel injector cup  36 . Alignment tab prongs  80 ,  82  may each be dual angle prongs and each may have dual contact surfaces that may contact flange  68 , such as for insertion and removal of fuel injector alignment tab  34 . More specifically, first alignment tab prong  80  may have a contact surface  86  and second alignment tab prong  82  may have contact surface  88 , which is a mirror image of contact surface  86 . Contact surfaces  86 ,  88  may be considered removal surfaces since contact surfaces  86 ,  88  contact flange  68  upon removal of fuel injector alignment tab  34  through notch  74  of flange  68 . Continuing, a removal angle “B” may be formed between surface  86  (i.e surface  86  extended into tab) and sidewall  94  of tab head  78 . The same angle as angle “B” may be formed between surface  88  (i.e surface  88  extended into tab) and sidewall surface  96  of tab head  78 . 
     First alignment tab prong  80  may have a contact surface  90  and second alignment tab prong  82  may have contact surface  92 , which is a mirror image of contact surface  90 . Contact surfaces  90 ,  92  may be considered insertion surfaces since contact surfaces  90 ,  92  contact flange  68  upon insertion of fuel injector alignment tab  34  into or through notch  74  of flange  68 . Continuing, an insertion angle or entry angle “A” may be formed between surface  90  and interior surface  98  that faces gap  84  of tab head  78 . The same angle as angle “A” may be formed between surface  92  and interior surface  100  that faces gap  84  of tab head  78 . Angle “A” which is an entry angle, may be smaller than angle “B,” which is a removal angle. Angle “A” ensures ease of insertion during alignment of injector  26  with fuel rail  24  while angle “B” ensures an ease of removal of injector  26  from flange  68  of fuel injector cup  36  for servicing; however, due to angle “B” being a larger angle, removal requires more force than insertion. 
     Turning now to  FIGS. 9-17 , additional details of fuel injector assembly  30  will be presented.  FIG. 9  depicts a side view of fuel injector  26  including fuel injector cup  36  attached (e.g. brazed) to fuel rail  24 . In  FIG. 9 , fuel injector cup  36  is mounted or clipped onto fuel injector alignment tab  34 , which may be plastic and overmolded directly to fuel injector  26 . A fuel injector exit tip  102  may be placed directly into an engine combustion chamber when in use. Turning now to  FIGS. 10 and 11 , a first position of fuel injector  26  relative to fuel injector cup  36  will be explained.  FIG. 10  depicts injector inlet  56  of injector  26  slightly beyond entrance  104  of fuel injector cup  36 . That is, injector inlet  56  is slightly within fuel injector cup  36 . When injector  26  is in the position depicted in  FIG. 10 , fuel injector alignment tab  34  is at the position depicted in  FIG. 11 ; thus, first and second alignment prongs  80 ,  82  of fuel injector alignment tab  34  have not yet entered into notch  74  in flange  68  of fuel injector cup  36 . Similarly, O-ring  58  has not yet entered into an interior of fuel injector cup  36 . 
     Turning now to  FIGS. 12 and 13 ,  FIG. 12  depicts injector inlet  56  within entrance  104  of fuel injector cup  36  such that O-ring  58  contacts interior sidewall  107  of fuel injector cup  36 . More specifically, O-ring  58  contacts interior wall  107  adjacent or beside flange  68 . When injector  26  is in the position depicted in  FIG. 12 , fuel injector alignment tab  34  is at the position depicted in  FIG. 13 . Thus, first and second alignment prongs  80 ,  82  of fuel injector alignment tab  34  have entered into gap or notch  74  in flange  68  of fuel injector cup  36 . More specifically, upon first and second alignment prongs  80 ,  82  contacting a first flange sidewall  106  and a second flange sidewall  108  during insertion in a direction indicated by arrow  110 , first and second alignment prongs  80 ,  82  begin to converge or move toward each other because prongs  80 ,  82  may be made from a flexible, plastic material. Additionally, because first and second alignment prongs  80 ,  82  have angled surfaces that contact flange  68 , the insertion force necessary to compress prongs  80 ,  82  upon contact with flange  68  is reduced over prongs with a greater contact angle which would require a greater insertion force in direction depicted by arrow  110 . 
     Turning now to  FIGS. 14 and 15 ,  FIG. 14  depicts injector inlet  56  of injector  26  protruding deeper or farther within fuel injector cup  36  compared to  FIG. 12 . In  FIG. 14 , O-ring  58  contacts interior wall  107  of fuel injector cup  36  and is located beyond or deeper than flange  68 . When injector  26  is in the position depicted in  FIG. 14 , fuel injector alignment tab  34  is at the position depicted in  FIG. 15 . Thus, first and second alignment prongs  80 ,  82  of fuel injector alignment tab  34  have been compressed toward each other by contact with flange  68  and forced deeper into or through notch  74  in flange  68  of fuel injector cup  36 . First alignment prong  80  has an apex  111  while second alignment prong  82  has an apex  112 . Apex  111  is the juncture of surface  86  and surface  90  of prong  80 , and apex  112  is the juncture of surface  88  and surface  92  of prong  82 . Upon insertion, when apexes  111 ,  112  moving completely through notch  74 , prongs  80 ,  82  become locked to a degree and will require a force to remove that is greater than the force of insertion. 
     As depicted in  FIG. 15 , prongs  80 ,  82  have moved through notch  74  to the extend that apexes  110 ,  112  are on a flange top side  114  as opposed to their position in  FIGS. 11 and 13  when apexes  110 ,  112  are on a flange bottom side  116 . Thus, when apexes  110 ,  112  are on a top side  114  of flange  68 , prongs  80 ,  82  are again relaxed and not under a bending stress as none of surfaces  86 ,  88 ,  90 ,  92  are in contact with flange  68 . When fuel injector  26  and more specifically, prongs  80 ,  82  are positioned as depicted in  FIG. 15 , fuel injector  26  is secured to fuel injector cup  36  and fuel rail  24  and thus injector  26  may not easily become dislodged or disconnected from fuel injector cup  36  during shipping and also fuel injector  26  may not become misaligned with fuel injector cup  36  or fuel rail  24  because fuel injector alignment tab  34  also aligns longitudinal axis of injector  26  with fuel rail  24 . Longitudinal axis  70  of fuel injector  26  may be aligned (e.g. perpendicularly) with longitudinal axis of fuel rail  24  since a width  118  of tab head  78 , which is parallel to movement direction of prongs  80 ,  82 , has a close tolerance with width of notch  74 . That is, tab head  78  has a width  118  nearly equal to that of width of notch  74 . Although  FIG. 15  depicts a location of fuel injector alignment tab  34  relative to flange  68  such that fuel injector alignment tab  34  will not easily pass back through alignment tab  34 , because prong gap  84  is still within notch  74 , prongs  80 ,  82  may still be susceptible to compression toward each other, or movement in general if force is applied to injector  26  or fuel rail  24 . 
       FIGS. 16 and 17  depict yet another position of fuel injector alignment tab  34  relative to flange  68  of fuel injector cup  36 . More specifically, fuel injector alignment tab  34  may be positioned such that an entirely solid portion  119  of tab head  78  lies within notch  74  of flange  68 . That is, base  120  of  FIG. 17  is a non-linear or curved portion defining prong gap  84 , is not located within notch  74  of flange  68 . After installing or inserting fuel injector alignment tab  34  through notch  74 , as depicted in  FIG. 17 , no force is exerted on prongs  80 ,  82  since prongs  80 ,  82  are located above or outside of notch  74 . Thus, combined with an interference fit or a close tolerance fit of solid portion  119  of tab head  78  and flange sidewalls  106 ,  108 , non-movement of prongs  80 ,  82  may be ensured. With non-movement of prongs  80 ,  82  with at least an interference fit or a close tolerance fit between solid portion  119  of tab head  78  and flange sidewalls  106 ,  108 , alignment of injector tip  56  with fuel rail  24  may also be ensured. Additionally, to further reduce or prevent any side to side motion or movement of injector  26  within fuel injector cup  36 , O-ring  58  compresses against cup interior sidewall  107  in an interference fit, as depicted in  FIGS. 12 ,  14  and  16 . 
     The teachings of the present disclosure reveal numerous advantages. An advantage is that O-ring  58  will be uniformly compressed within fuel injector cup  36  because of fuel injector alignment tab  34 , which prevents inserting fuel injector  26  into fuel injector cup  36  in an angled manner. Thus, the longitudinal axis of fuel injector cup  36  and longitudinal axis of injector  26  will always coincide. Another advantage is that fuel injector alignment tab  34  is an integral part of fuel injector  26  as opposed to a separate piece. By integrating fuel injector  26  and fuel injector alignment tab  34  by overmolding, for example, separate pieces and additional fasteners are not necessary. Yet another advantage is that the force necessary to install and remove fuel injector alignment tab  34  from flange  68  of fuel injector cup  36  are different. The force required for installation is less than the force required for removal of the fuel injector alignment tab  34 . 
     The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the invention, and all such modifications are intended to be included within the scope of the invention.