The invention relates to a fuel delivery system arrangement for connecting an electric operated fuel injector between a fuel rail and an air intake of a spark-ignited, internal combustion engine.
Spark-ignited, fuel-injected internal combustion engines are often used in automotive vehicles. Fuel is injected into an intake system of such an engine by electric operated fuel injectors of a fuel rail (sometimes referred to as a fuel manifold) assembled to the engine.
Targeted types of fuel injectors inject fuel into the vehicle engine in a direction, or directions, that are other than along the fuel injector axial centerline. A split stream fuel injector is an example of a targeted fuel injector. When a targeted fuel injector is used in an engine, the fuel injector has to have a particular angular or circumferential orientation about its centerline so that the direction(s) of fuel injection will be properly targeted. Improperly targeted fuel injectors may derogate engine performance and/or compliance with applicable vehicle emission requirements.
Proper targeting of a fuel injector typically requires a proper axial positioning of the fuel injector. This is typically achieved by positioning the fuel injector nozzle, which contains one or more metering orifices from which fuel is injected into an engine, in a fixed geometric relation to a socket receptacle of the engine intake system into which the nozzle is inserted in a sealed manner. When a fuel rail containing fuel injectors that have been properly circumferentially located in respective outlet cups of the fuel rail is assembled to an engine that has injector-receiving socket receptacles, the act of inserting the nozzles into properly sealed relationship with the socket receptacles can complete proper targeting of the fuel injectors. The achievement of the correct circumferential location of the fuel injector to the fuel rail outlet cup is referred to as “clocking” the fuel injector.
A fuel rail may comprise attachment features, aperture brackets for example, with which threaded fasteners are associated to fasten the fuel rail to an engine. Once the fuel injector nozzles have seated in properly targeted positions in the socket receptacles, a need for further tightening of such fasteners in order to secure the fuel rail to the engine may induce undesired stress, distortion and/or movement. For example, if fuel injector nozzles have been seated in properly targeted positions in respective socket receptacles in engine air intake manifold runners before the fuel rail attachment fasteners have been fully torqued, the fuel rail may distort in some way, and/or there may be some relative movement between some component parts, as the fasteners are finally tightened to full installation torque. With prevailing manufacturing methods and dimensional tolerances of manufactured parts, it seems that the possibility of such distortion, or movement of component parts, at time of fuel rail assembly to an engine, cannot be totally foreclosed in all circumstances.
It has been known to mechanically retain a fuel injector in a fuel rail outlet cup by a retention clip that constrains the two against any substantial movement, both circumferentially and axially. A fuel rail that incorporates such a capability may improve serviceability should it become necessary to remove the fuel rail from an engine and thereafter reattach it.
Due to the enhanced stringency of vehicle emission requirements and the use of four valve cylinder heads with two intake ports, it is now more important than ever to insure the fuel injectors are properly clocked. Therefore the requirements that fuel injectors be properly clocked when inadvertently twisted during assembly or maintenance operations are greater than that previously required. Many prior fuel delivery system arrangements retain the fuel injector to the cup with a double C-type clamp clip. The double C-type clamp clip has a primary C clamp which engages an arcuate slot of the injector body. The primary C clamp retains the injector body in a generally axial direction. A secondary C clamp is typically provided which extends generally perpendicular from the primary C clamp. The secondary C clamp typically has slots or projections which interact with a flange portion of an outlet cup to make it a click-on type connection. The secondary C clamp will typically have a contact surface to prevent rotation of the fuel injector body with respect to the fuel injector outlet other than its desired angular position. An example of such a clip is shown in U.S. Pat. No. 5,040,512.
There has been a tendency from many of the prior clips to lose their retention with the fuel injector body when the fuel injector is inadvertently twisted during a maintenance operation or during a misassembly.
It is desirable to provide an improved fuel delivery system wherein the clip is less susceptible to being splayed open whenever a fuel injector is torqued inadvertently.
The fuel delivery system arrangement of the present invention provides a clip having an inner circumferential surface which engages the fuel injector body but has an outer circumferential surface which is inserted within the fuel rail injector cup outlet. Therefore an inadvertent torque placed upon the fuel injector will cause the outer diameter of the clip to engage the interior of the cup and thereafter be prevented from opening as in prior clip designs.
Other features of the invention will become more apparent from a review of the ensuing drawings and description.
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The fuel injector has a body inlet portion 40 which has an inlet opening 42 extending therethrough. The inlet portion 40 is insertable within the cup 26. An O-ring 44 is sealably engaged with the inlet portion 40 of the fuel injector and additionally is sealably engaged with an interior inner diameter 46 of the cup. A mid portion 48 of the injector has slot grooves 50 (
The fuel delivery system includes an arcuate clip 60. The clip 60 functions to radially and axially retain the fuel injector 20 to the cup 26 and also functions to clock or to angularly orientate the fuel injector 20 to ensure its proper angular positional alignment along its longitudinal axis. The clip 60 has an outer periphery or circumference 62. The outer circumference 62 will be sized to be slightly greater than that than the inner diameter 46 of the cup when the clip is in its free state and slightly less when circumferentially compressed for insertion into the cup 26. The clip 60 has an inner peripheral or circumferential surface 64. The inner circumferential surface 64 of the clip has non-relative torsional engagement with the mid portion 48 of the fuel injector. The inner circumferential surface 64 has flats 66 which engage the flats 52 of the injector body. The clip 60 has an open end between the contact points 68. The distance between the contact points 68 will typically be slightly less than or the same as the width between the flats 52 of the injector body mid portion and the injector body mid portion will only come within the interior of the clip 60 by spreading apart the contact points 68. The clip 60 also has radially extending arms 70. Radially extending arms 70 each have two fingers 72 which are positioned on top of the cup flange 32.
During the assembly operation the contact points 68 are spread apart or wedged apart and ride upon the flats 52 of the fuel injector body until such time that the flats 66 are allowed to engage with the flats 52. A top or extreme sectional end of the injector body mid portion noted as item 76 (
Any inadvertent attempt to twist the fuel injector 20 will cause the clip to open up and engage the interior diameter 46 of the cup. The clip 60 will not be allowed to open up to release the fuel injector 20 unless it or the cup 26 is deformed, which will require substantial force. To release the fuel injector 20 for maintenance, the arms and fingers 72 will be deformed and removed through the slots 34.
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Clip 160 has radially extending arms 170 which include a downwardly extending portion 171, a base portion 173, an upward extending portion 175 and a downwardly extending portion 177. The arms have a flared finger 172 which has a generally horizontal downward facing contact surface 174. The shoulder also provides a generally vertical radially inward contact surface 179.
The cup flange 132 has generally radial projections 128 (shown only in
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While embodiments of the present invention have been explained it will be readily apparent to those skilled in the art of the various modifications and changes which can be made from the present invention without departing from the spirit and scope of the accompanying claims.
Number | Name | Date | Kind |
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5167213 | Bassler et al. | Dec 1992 | A |
5803052 | Lorraine et al. | Sep 1998 | A |
6019089 | Taylor et al. | Feb 2000 | A |
6668803 | McClean et al. | Dec 2003 | B1 |
Number | Date | Country | |
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20060118091 A1 | Jun 2006 | US |