Patent Publication Number: US-2021190023-A1

Title: Bolt style suspended fuel injector

Description:
FIELD 
     The present disclosure relates to suspended fuel injectors. 
     BACKGROUND 
     The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
     Internal combustion engines typically have a fuel rail that supplies fuel to fuel injectors. The fuel injectors have a tip that extends through an aperture in the cylinder head. The tip is configured to selectively emit fuel into the combustion chamber of the engine. The tip can be configured to emit the fuel in a specific direction and spray pattern relative to the combustion chamber such that an incorrect rotational orientation of the tip relative to the cylinder head can result in decreased performance. In typical engine configurations, the fuel rail is affixed to the engine such that the fuel rail presses an end of the fuel injector into contact with the cylinder head to hold the fuel injector in position between the fuel rail and the cylinder head. 
     SUMMARY 
     In one form, the present disclosure provides for a fuel injector assembly including a fuel cup, a fuel injector, and a bolt. The fuel cup defines a cavity and a cup inlet. The fuel injector includes an injection tip and an upper housing. The injection tip defines a fuel outlet opposite the upper housing. The upper housing defines a fuel inlet and a threaded bore. The fuel inlet is disposed within the cavity and in fluid communication with the cup inlet. The threaded bore is disposed within the fuel cup. The bolt is threadably engaged with the threaded bore. The bolt couples the upper housing to the fuel cup. 
     In another form, the present disclosure provides for a fuel injector assembly including a fuel rail, a fuel cup, a fuel injector, a bolt, and an upper seal. The fuel cup is coupled to the fuel rail. The fuel cup defines a cavity, a bolt bore, and a cup inlet. The bolt bore and cup inlet are open to the cavity. The cup inlet is configured to receive fuel from the fuel rail. The fuel injector includes an injection tip and an upper housing. The injection tip defines a fuel outlet opposite the upper housing. The upper housing defines a fuel inlet and a threaded bore. The fuel inlet is disposed within the cavity and in fluid communication with the cup inlet. The threaded bore is disposed within the fuel cup. The bolt extends through the bolt bore and is threadably engaged with the threaded bore to couple the upper housing to the fuel cup. The upper seal inhibits fluid communication from the cavity to an exterior of the fuel cup via the bolt bore. 
     In yet another form, the present disclosure provides for a fuel injector including an injection tip and an upper housing. The injection tip defining a fuel outlet. The upper housing is opposite the fuel outlet. The upper housing is disposed about a longitudinal axis of the fuel injector. A distal portion of the upper housing is coupled to the injection tip. The upper housing defines a fuel inlet configured to receive fuel from a fuel rail. A proximal portion of the upper housing defines a threaded bore coaxial with the longitudinal axis. 
     Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which: 
         FIG. 1  is a side view of a fuel injector assembly in accordance with the teachings of the present disclosure, illustrating an orientation member of a first construction in accordance with the teachings of the present disclosure; 
         FIG. 2  is a perspective view of a portion of the fuel injector assembly of  FIG. 1 ; 
         FIG. 3  is a perspective view of a portion of a fuel injector assembly similar to that of  FIG. 2  but with an orientation member of a second construction in accordance with the teachings of the present disclosure; 
         FIG. 4  is a cross-sectional view of a portion of the fuel injector assembly of  FIG. 3 ; 
         FIG. 5  is a perspective cross-sectional view of a portion of a fuel injector assembly of a third construction in accordance with the teachings of the present disclosure; 
         FIG. 6  is a cross-sectional view of a portion of a fuel injector assembly of a fourth construction in accordance with the teachings of the present disclosure; and 
         FIG. 7  is a perspective view of a portion of a fuel injector of a fifth construction in accordance with the teachings of the present disclosure. 
     
    
    
     The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
     DETAILED DESCRIPTION 
     The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. 
     In some applications, such as some vehicle engines, the contact between the cylinder head and the end of the fuel injector can transmit vibrations through or from the engine. These vibrations can manifest as audible noise or can be transmitted to other components, such as sensors for example, where vibration may be detrimental to performance or longevity of those components. 
     In an effort to reduce such vibration transmission paths, suspended injectors have been specified for some engine applications in which the suspended fuel injectors do not abut the cylinder head. However, current solutions for affixing a suspended fuel injector between the cylinder head and the fuel rail are complicated and costly. 
     The present disclosure provides for a suspended fuel injector that overcomes these and other issues with typical fuel injectors. 
     Referring to  FIGS. 1 and 2 , a fuel injector assembly  10  is illustrated with a portion of an internal combustion engine  14 . In the example provided, the internal combustion engine  14  is an engine of a vehicle (not shown), though the engine  14  may be used in other applications (e.g., machinery, generators). Examples of vehicles that may include the engine  14  may include, without limitation, automobiles, trucks, recreational vehicles, watercraft, and all-terrain vehicles. The engine  14  may provide motive power to drive wheels (not shown) of the vehicle such as through a transmission (not shown) of the vehicle for example. Additionally or alternatively, the engine  14  may charge a vehicle battery (not shown) that may supply electric power to electric motors (not shown) that provide some or all of the motive power to the wheels (e.g., an electric or hybrid vehicle). 
     In the example provided, the engine  14  is a piston-cylinder engine including a combustion chamber  74  at least partially defined by a cylinder head  46  and a piston (not shown). The combustion chamber  74  may also be at least partially defined by a portion of an engine block (not shown) of the engine  14 . 
     The fuel injector assembly  10  generally provides fuel (e.g., gasoline, diesel, ethanol) to the combustion chamber  74 . The fuel injector assembly  10  includes a fuel rail  18 , a fuel cup  22 , a fuel injector  26 , and a fastener  30 . The fuel injector assembly may also include an orientation member  34 . The fuel rail  18  generally receives fuel from a fuel supply system (not shown; e.g., a fuel tank via a fuel pump) and provides the fuel to one or more fuel cups  22  (one of which is illustrated), each of which provides fuel to a corresponding fuel injector  26  (one of which is illustrated). Each fuel injector  26  generally provides fuel to the combustion chamber  74 . 
     More specifically, the fuel rail  18  defines an internal passageway  38  that is connected for fluid communication with the fuel supply system (not shown) and configured to receive fuel from the fuel supply system. The fuel rail  18  is attached to a structure (not shown; e.g., a frame or a part of the engine  14 ) via one or more brackets (not shown). The fuel rail  18  is attached to the structure (not shown) such that the fuel rail  18  is a fixed distance from the cylinder head  46  of the engine  14 . 
     The fuel cup  22  is coupled to the fuel rail  18  (e.g., brazed or welded thereto) and defines an internal cavity  50  in fluid communication with the internal passageway  38  of the fuel rail  18  such that the fuel cup  22  can receive fuel from the fuel rail  18 . While a single fuel cup  22  is illustrated, a plurality of fuel cups  22  may be coupled to the fuel rail  18  along the length of the fuel rail  18  such that each fuel cup  22  can receive fuel from the fuel rail  18 . 
     The fuel injector  26  includes an injection tip  54 , an upper housing  58 , and an electrical connector  62 . The injection tip  54  is received through a bore  66  in the cylinder head  46  such that a terminal end  70  of the injection tip  54  is configured to spray fuel into the combustion chamber  74  of the engine  14 . The injection tip  54  may include a seal member  78  configured to form a seal with an inner surface  82  of the bore  66  of the cylinder head  46 . The injection tip  54  is disposed about a central axis  86  of the fuel injector  26  and extends longitudinally from a distal portion  90  of the upper housing  58 . 
     A proximal portion  94  of the upper housing  58  is disposed within the fuel cup  22  and configured to receive fuel therefrom. Internal valve components  96  are disposed within the upper housing  58  and configured to selectively release fuel into the combustion chamber  74  via a fuel outlet  98  defined by the terminal end  70  of the injection tip  54 . The internal valve components  96  are controlled by power and/or signals received via the electrical connector  62 . 
     The fuel outlet  98  of the injection tip  54  can be configured to produce a specific spray pattern and the orientation member  34  is configured to maintain the fuel injector  26  in a predetermined rotational orientation relative to the combustion chamber  74 . In the example provided, the orientation member  34  is a clip that includes legs  102  and a finger  104 . The legs  102  engage the upper housing  58  below the fuel cup  22  such that the orientation member does not rotate relative to the upper housing  58 . The finger  104  extends into a notch  106  defined by the fuel cup  22  such that the finger inhibits rotation of the fuel injector  26  relative to the fuel cup  22 . While shown herein as a clip, other constructions of the orientation member  34  can be used. 
     The fuel injector assembly  10  is a suspended fuel injection system such that the distal portion  90  of the upper housing  58  does not contact the engine  14 . In other words, the upper housing  58  is axially spaced apart from the cylinder head  46  by a gap  114 . In the example provided, the orientation member  34  may not be sufficient to maintain the axial position of the fuel injector  26  relative to the cylinder head  46 . As described in greater detail below, the fastener  30  (e.g., a bolt or screw) couples the upper housing  58  to the fuel cup  22  to maintain the axial position of the fuel injector  26  relative to the cylinder head  46  and to maintain the gap  114  therebetween. 
     Referring to  FIGS. 3 and 4 , a portion of a fuel injector assembly  10  of a second construction is illustrated. The fuel injector assembly  10  shown in  FIGS. 3 and 4  is similar to the fuel injector assembly  10  shown in  FIGS. 1 and 2  except that instead of the clip-type orientation member  34  ( FIGS. 1 and 2 ), the orientation member  34 ′ includes a pair of prongs  210 ,  212  that are coupled together on one end  214  to form a generally “U” shaped pin member. The end  214  of the orientation member  34 ′ is disposed external of the fuel cup  22  and each prong  210 ,  212  extends through a corresponding aperture  218 ,  220  in the fuel cup  22 . The apertures  218 ,  220  are parallel to each other, are on opposite sides of the axis  86 , and extend longitudinally through the fuel cup  22  into the cavity  50  such that the prongs  210 ,  212  are perpendicular to the axis  86 . In the example provided, the apertures  218 ,  220  extend fully through the fuel cup  22  such that the prongs  210 ,  212  exit an opposite side of the fuel cup  22 , though other configurations can be used. 
     In the example provided, the prongs  210 ,  212  are generally cylindrical in shape, though other configurations can be used. The prongs  210 ,  212  fit within corresponding channels  222 ,  224  defined by the upper housing  58  when the fuel injector  26  is positioned in the predetermined rotational orientation. In the example provided the channels  222 ,  224  are open through a radially outward surface  226  of the upper housing  58 . 
     An outer wall  110  of the fuel cup  22  includes a cup inlet  230  open to the internal passageway  38  of the fuel rail  18  ( FIG. 1 ) and open to a region  234  of the cavity  50  to provide fluid communication between the fuel rail  18  ( FIG. 1 ) and the region  234  of the cavity  50 . In the example provided, the cup inlet  230  is perpendicular to the apertures  218 ,  220 , though other configurations can be used. 
     A bottom end  238  of the fuel cup  22  defines an aperture  240  that is open into the cavity  50  such that the proximal portion  94  of the upper housing  58  of the fuel injector  26  can be inserted into the cavity  50  through the bottom end  238  of the fuel cup  22 . A top end  242  of the fuel cup  22  is opposite the bottom end  238  and is generally closed by a top wall  246  of the fuel cup  22 . The top wall  246  of the fuel cup  22  defines a fastener bore, referred to herein as a bolt bore  250 , open through the top wall  246  and into the cavity  50 . The bolt bore  250  is coaxial with the axis  86 . The cup inlet  230  is disposed axially between the top wall  246  and the apertures  218 ,  220 . In the example provided, the bolt bore  250  is not threaded and has a diameter greater than threads of an externally threaded portion  254  of the fastener  30  such that the threaded portion  254  can be received through the bolt bore  250  and the fastener  30  is free to rotate in the bolt bore  250  without translating the fastener  30  relative to the fuel cup  22 . In the example provided, a head portion  258  of the fastener  30  extends radially outward of the threaded portion  254  and engages a top surface  262  of the top wall  246  of the fuel cup  22 . 
     Returning to the example provided, a terminal end  266  of the proximal portion  94  of the upper housing  58  includes a threaded bore  270  coaxial with the axis  86  and a seal surface  274  disposed about the threaded bore  270 . The threaded bore  270  aligns with the bolt bore  250  and the threaded portion  254  of the fastener  30  is received through the bolt bore  250  to threadably engage with the threaded bore  270 . The seal surface  274  is configured to engage a mating seal surface  278  defined by the top wall  246  within the cavity  50  to form a fluid-tight seal between the proximal portion  94  and the top wall  246  to inhibit fluid from exiting the fuel cup  22  via the bolt bore  250 . In the example provided, the seal surface  274  and the mating seal surface  278  are both metal surfaces to form a metal-to-metal seal therebetween. In the example provided, the seal surface  274  and the mating seal surface  278  are both frustoconically shaped, though other shapes may be used. Thus, the seal surface  274  and the mating seal surface  278  form a first seal  282  between the upper housing  58  and the fuel cup  22 . 
     The fastener  30  can secure the fuel injector  26  to the fuel cup  22  to inhibit axial motion therebetween and maintain the gap  114  ( FIG. 1 ) between the distal portion  90  of the upper housing  58  and the cylinder head  46 . An additional thread sealant (not shown) may also optionally be used to seal the threaded portion  254  of the fastener  30  with the bolt bore  250  and/or with the threaded bore  270 . In an alternative configuration, not shown, a seal (e.g., a washer or gasket) can optionally form a seal between the head portion  258  of the fastener  30  and the top surface  262  of the top wall  246  of the fuel cup  22  to form a seal therebetween. 
     Referring specifically to  FIG. 4 , the upper housing  58  defines a fuel inlet  310  open through a radially outer surface  314  of the upper housing  58 . The fuel inlet  310  extends radially inward to a central passageway  318  that provides fuel to the injection tip  54  ( FIG. 3 ) via the internal valve components  96  ( FIG. 3 ). The fuel inlet  310  is open to the region  234  of the cavity  50  such that the fuel inlet  310  is in fluid communication with the cup inlet  230  via the cavity  50 . 
     The fuel injector assembly  10  also includes a first lower seal member  322  disposed within the cavity  50  and axially between the fuel inlet  310  and the open bottom end  238  of the fuel cup  22 . The first lower seal member  322  is an annular body (e.g., an O-ring) disposed coaxially about the upper housing  58  and in contact with the radially outer surface  314  of the upper housing  58  and an interior surface  326  of the outer wall  110  of the fuel cup  22  to form a seal therebetween. The first lower seal member  322  inhibits fuel from exiting the cavity via the open bottom end  238  of the fuel cup  22 . In the example provided, the first lower seal member  322  is also axially between the fuel inlet  310  and the orientation member  34 ′ to inhibit fuel from exiting the cavity  50  via the apertures  218 ,  220  ( FIG. 3 ). Thus, the first lower seal member  322  forms a second seal  330  between the upper housing  58  and the fuel cup  22 . 
     In the example provided, the fuel injector assembly  10  also includes a second lower seal member  334 . The second lower seal member  334  is an annular body disposed coaxially about the upper housing  58  and axially between the first lower seal member  322  and the open bottom end  238 . The second lower seal member  334  includes a frustoconical surface  338  that defines the central bore of the annular second lower seal member  334  such that the central bore of the annular second lower seal member  334  has a smaller diameter proximate to the first lower seal member  322  and a larger diameter proximate to the open bottom end  238 . The upper housing  58  defines a mating frustoconically shaped surface  346  that contacts and seals with the frustoconical surface  338  of the second lower seal member  334 . 
     An upper surface  350  of the second lower seal member  334  can contact and seal with the first lower seal member  322 . A radially outward surface  354  of the second lower seal member  334  can seal with the interior surface  326  of the outer wall  110  of the fuel cup  22 . In the example provided, the frustoconical surface  338  does not widen all the way to the radially outward surface  354 . In other words, a lower surface  358 , which can be parallel to the upper surface  350 , extends radially outward between the frustoconical surface  338  and the radially outward surface  354 . The lower surface  358  is seated on and can seal with a shoulder  362  of the upper housing  58  that extends radially outward from the radially outward surface  354 . Thus, the second lower seal member  334  can form a back-up seal for the first lower seal member  322  and the first and second lower seal members  322  and  334  can cooperate to form a lower seal assembly  364 . 
     In the example provided, the fuel injector  10  may optionally include a stopper ring  366 . The stopper ring  366  can be a snap-on ring or c-clip partially received in a circumferential groove  370  recessed radially inward from the radially outward surface  314 . The stopper ring  366  can act to inhibit the first and second lower seal members  322 ,  334  from translating off of the proximal portion  94 . 
     Referring to  FIG. 5 , a portion of a fuel injector assembly  10  of a third construction is illustrated. The fuel injector assembly  10  of  FIG. 5  is similar to the fuel injector assemblies  10  of  FIGS. 1-4 , except as otherwise shown or described herein. Specifically, the seal surface  274 ′ of the fuel injector assembly  10  of  FIG. 5  is a convex spherically shaped surface instead of the frustoconical shape of the fuel injector assembly  10  of  FIG. 4 . The spherically shaped seal surface  274 ′ can mate with the frustoconically shaped mating seal surface  278  of the fuel cup  22 . In an alternative configuration, not specifically shown, the mating seal surface  278  may be another shape, such as flat or concave spherical. While not specifically shown, the seal surface  274 ′ and/or the mating seal surface  278  can be any suitable mating shape for forming a direct contact fluid seal. 
     Referring to  FIG. 6 , a portion of a fuel injector assembly  10  of a fourth construction is illustrated. The fuel injector assembly  10  of  FIG. 6  is similar to the fuel injector assembly  10  of  FIGS. 1-5 , except as otherwise shown or described herein. Specifically, the proximal portion  94 ′ of the upper housing  58  of  FIG. 6  may or may not include the seal surface  274  ( FIG. 4 ) that engages the mating seal surface  278  ( FIG. 4 ). In the example shown, the proximal portion  94 ′ does not include the seal surface  274  ( FIG. 4 ) and the proximal portion  94 ′ does not directly contact the top wall  246  of the fuel cup  22 . Instead, a first upper seal member  510  forms the first seal  282 ′ between the upper housing  58  and the fuel cup  22 . The first upper seal member  510  is an annular body (e.g., an O-ring) disposed coaxially about the upper housing  58  and disposed axially between the fuel inlet  310  and the terminal end  266  of the proximal portion  94 . The first upper seal member  510  contacts a radially outward surface  514  of the upper housing  58  and the interior surface  326  of the outer wall  110  of the fuel cup  22  to form a seal therebetween to inhibit fuel from reaching the fastener and exiting via the bolt bore  250 . 
     In the example provided, the fuel injector assembly  10  of  FIG. 6  also includes a second upper seal member  518 . The second upper seal member  518  is an annular body disposed coaxially about the upper housing  58  and axially between the first upper seal member  510  and the terminal end  266  of the proximal portion  94 . The second upper seal member  518  includes a frustoconical surface  522  that defines the central bore of the annular second upper seal member  518  such that the central bore of the annular second upper seal member  518  has a smaller diameter proximate to the first upper seal member  510  and a larger diameter proximate to the terminal end  266  of the proximal portion  94 . The upper housing  58  defines a mating frustoconically shaped surface  530  that contacts and seals with the frustoconical surface  522  of the second upper seal member  518 . 
     A lower surface  534  of the second upper seal member  518  can contact and seal with the first upper seal member  510 . A radially outward surface  538  of the second upper seal member  518  can seal with the interior surface  326  of the outer wall  110  of the fuel cup  22 . In the example provided, the frustoconical surface  522  does not widen all the way to the radially outward surface  538 . In other words, an upper surface  542 , which can be parallel to the lower surface  534 , extends radially outward between the frustoconical surface  522  and the radially outward surface  538 . The upper surface  542  is seated on and can seal with a shoulder  546  of the fuel cup  22 . Thus, the second upper seal member  518  can form a back-up seal for the first upper seal member  510  and the first and second upper seal members  510  and  518  can cooperate to form an upper seal assembly  548 . 
     In the example provided, the fuel injector  10  may optionally include the lower stopper ring  366 . The stopper ring  366  can be a snap-on ring or c-clip partially received in the circumferential groove  370  recessed radially inward from the radially outward surface  314 . The stopper ring  366  can be between the fuel inlet  310  and the first lower seal member  322  to act to inhibit the first and second lower seal members  322 ,  334  from translating upwards relative to the proximal portion  94 ′. The fuel injector  10  may also optionally include an upper stopper ring  550 . The upper stopper ring  550  can be a snap-on ring or c-clip partially received in a circumferential groove  554  recessed radially inward from the radially outward surface  514 . The upper stopper ring  550  can be between the fuel inlet  310  and the first upper seal member  510  to act to inhibit the first and second upper seal members  510 ,  518  from translating downwards relative to the proximal portion  94 . 
     Referring to  FIG. 7 , a portion of a fuel injector assembly  10  of a fifth construction is illustrated. The fuel injector assembly  10  of  FIG. 7  is similar to the fuel injector assembly  10  of  FIGS. 1-6 , except as otherwise shown or described herein. Specifically, instead of the clip-type orientation member  34  ( FIGS. 1 and 2 ) or the pin-type orientation member  34 ′ ( FIGS. 3 and 4 ), the orientation member  34 ″ is integrally formed with the upper housing  58 . In the example provided, the orientation member  34 ″ is a protrusion or fin  710  that extends from a portion  712  of the upper housing  58  that forms part of the electrical connector  62 . The fin  710  has a shape that fits within a slot  714  defined by the fuel cup  22 . In the example provided, the slot  714  is defined by a rim  716  of the fuel cup  22  that extends radially outward of the outer wall  110 , though other configurations can be used. The fin  710  can only fit within the slot  710  when the fuel injector  26  is correctly oriented. The fin  710  cooperates with the slot  710  to inhibit rotation of the fuel injector  26  relative to the fuel cup  22 . 
     In an alternative configuration, not specifically shown, the fin  710  can extend from a different part of the upper housing  58 . In another alternative configuration, not specifically shown, the fuel cup  22  can have a protrusion or fin that fits within a slot defined by the upper housing  58 . 
     Based on the foregoing, in one form, the present disclosure is directed toward a fuel injector assembly which includes a fuel cup, a fuel injector, and a bolt. The fuel cup defines a cavity and a cup inlet. The fuel injector includes an injection tip and an upper housing. The injection tip defines a fuel outlet opposite the upper housing. The upper housing defines a fuel inlet and a threaded bore. The fuel inlet is disposed within the cavity and in fluid communication with the cup inlet. The threaded bore is disposed within the fuel cup. The bolt is threadably engaged with the threaded bore. The bolt couples the upper housing to the fuel cup. 
     In one form, the fuel cup defines a bolt bore aligned with the threaded bore. The bolt extends through the bolt bore to engage the threaded bore. 
     In another form, a surface of the upper housing contacts a surface of the fuel cup to define an upper seal that isolates the bolt bore from fluid communication with the fuel inlet. 
     In yet another form, the fuel injector assembly further includes an upper seal between the upper housing and the fuel cup. The upper seal isolates the threaded bore from fluid communication with the fuel inlet. 
     In still another form, the upper housing defines a seal surface disposed about the threaded bore that contacts a mating seal surface of the fuel cup to form the upper seal. 
     In another form, the fuel injector assembly further includes a first upper seal member disposed about the upper housing. The first upper seal member contacts the upper housing and the fuel cup to form the upper seal. 
     In yet another form, the first upper seal member is a resilient material. 
     In still another form, the fuel injector assembly further includes a second upper seal member disposed about the upper housing. The second upper seal member contacts the upper housing and the fuel cup to form a second upper seal between the upper housing and the fuel cup. The first upper seal is axially between the fuel inlet and the second upper seal. 
     In another form, the fuel injector assembly further includes a lower seal between the upper housing and the fuel cup. The fuel inlet is disposed between the upper seal and the lower seal. 
     In yet another form, the fuel injector assembly further includes a first lower seal member disposed about the upper housing. The first lower seal member contacts the upper housing and the fuel cup to form the lower seal. The first lower seal member is a resilient material. 
     In still another form, the fuel injector assembly further includes a second lower seal member disposed about the upper housing. The second lower seal member contacts the upper housing and the fuel cup to form a second lower seal between the upper housing and the fuel cup. The first lower seal is axially between the fuel inlet and the second lower seal. 
     In another form, the threaded bore is coaxial with a longitudinal axis of the fuel injector. 
     In still another form, the fuel injector assembly further includes an orientation member. The orientation member engages the fuel cup and the upper housing to inhibit rotation of the fuel injector relative to the fuel cup. 
     In yet another form, the fuel cup defines an orientation aperture open through an exterior wall of the fuel cup. The orientation member extends through the orientation aperture and engages the upper housing within the fuel cup when the upper housing is in a predetermined rotational alignment with the fuel cup. 
     In another form, the fuel injector assembly further includes an upper seal and a lower seal. The upper seal isolates the threaded bore from fluid communication with the fuel inlet. The lower seal isolates the orientation member from fluid communication with the fuel inlet. 
     In a further form, the disclosure is directed toward a fuel injector assembly which includes a fuel rail, a fuel cup, a fuel injector, a bolt, and an upper seal. The fuel cup is coupled to the fuel rail. The fuel cup defines a cavity, a bolt bore, and a cup inlet. The bolt bore and cup inlet are open to the cavity. The cup inlet is configured to receive fuel from the fuel rail. The fuel injector includes an injection tip and an upper housing. The injection tip defines a fuel outlet opposite the upper housing. The upper housing defines a fuel inlet and a threaded bore. The fuel inlet is disposed within the cavity and in fluid communication with the cup inlet. The threaded bore is disposed within the fuel cup. The bolt extends through the bolt bore and is threadably engaged with the threaded bore to couple the upper housing to the fuel cup. The upper seal inhibits fluid communication from the cavity to an exterior of the fuel cup via the bolt bore. 
     In another form, the fuel injector assembly further includes a lower seal between the upper housing and the fuel cup. The fuel inlet is axially between the upper seal and the lower seal. 
     In still a further form, the disclosure is directed toward a fuel injector including an injection tip and an upper housing. The injection tip defining a fuel outlet. The upper housing is opposite the fuel outlet. The upper housing is disposed about a longitudinal axis of the fuel injector. A distal portion of the upper housing is coupled to the injection tip. The upper housing defines a fuel inlet configured to receive fuel from a fuel rail. A proximal portion of the upper housing defines a threaded bore coaxial with the longitudinal axis. 
     In yet another form, the fuel injector further includes a seal surface disposed about the threaded bore and configured to sealingly engage a fuel cup. 
     In still another form, the fuel injector further includes an upper seal member and a lower seal member. The upper seal member is disposed about the upper housing and configured to form a seal with a fuel cup. The lower seal member is disposed about the upper housing and configured to form a seal with the fuel cup. The fuel inlet is disposed axially between the upper and lower seal members. 
     Unless otherwise expressly indicated herein, all numerical values indicating mechanical/thermal properties, compositional percentages, dimensions and/or tolerances, or other characteristics are to be understood as modified by the word “about” or “approximately” in describing the scope of the present disclosure. This modification is desired for various reasons including industrial practice, manufacturing technology, and testing capability. 
     As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.” 
     The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.