The present invention relates to fuel injectors for supplying fuel to a fuel consuming device and more particularly to an arrangement for retaining such a fuel injector to a fuel rail socket of a fuel rail.
Modern internal combustion engines typically utilize one or more fuel injectors for metering a precise quantity of fuel to be combusted in respective combustion chambers such that the combustion is initiated, by way of non-limiting example only, with a spark from a spark plug. Combustion of the fuel may be used, for example, to propel a motor vehicle and to generate electricity or drive other accessories in support of operation of the motor vehicle. Fuels in liquid form that are commonly used to power the internal combustion engine include, by way of non-limiting example only, gasoline, ethanol, alcohol, diesel fuel, and the like and blends of two or more thereof. Until more recently, fuel injectors commonly referred to as port fuel injectors were predominantly used. Port fuel injectors inject fuel into a port of an intake manifold where the fuel is mixed with air prior to being drawn into the combustion chamber of the internal combustion through an intake valve of the cylinder head. A typical port fuel injector is show in U.S. Pat. No. 7,252,249 to Molnar. In order to increase fuel economy and reduce undesirable emissions produced by combustion of the fuel, direct injection fuel injectors have been increasing in use. As the name suggests, direct injection fuel injectors inject fuel directly into the combustion chamber. An example of such a direct injection fuel injector is described in Unites States Patent Application Publication No. US 2012/0067982 A1 to Perry et al., the disclosure of which is incorporated herein by reference in its entirety.
In a typical internal combustion engine, a plurality of direct injection fuel injectors such as those disclosed in Perry et al. are attached to a common volume of a fuel rail which contains pressurized fuel. The fuel rail includes a plurality of fuel rail sockets which each receive a portion of a respective fuel injector therein. In use, the pressurized fuel acts on the fuel injectors, thereby trying to push the fuel injectors out of their respective fuel rail sockets. It may be desirable to suspend the fuel injectors from their respective fuel rail sockets in order to minimize contact between the internal combustion engine and the fuel injectors, thereby minimizing noise and heat transfer. U.S. Pat. Nos. 8,646,434; 8,813,722; and U.S. Pat. No. 7,856,962 to Harvey et al.; U.S. Pat. No. 8,479,710 to Davis; U.S. Pat. No. 9,567,961 to Cass et al., and U.S. Pat. No. 7,798,127 to Notaro et al.; United Stated Patent Application Publication Nos. US 2010/0012093 A1 to Pepperine et al. and US 2015/0330347 A1 to Pohlmann et al.; and Research Disclosure Publication No. 601008 teach various arrangements for retaining a fuel injector to a fuel rail socket. However, these various arrangements for retaining the fuel injector to the fuel rail socket may be costly and difficult to implement. Furthermore, some of these arrangements for retaining the fuel injector to the fuel rail socket may not be satisfactory when subjected to fuel pressures which are ever increasing in an attempt to achieve greater efficiency and reduced emissions. Consequently, improvements in retaining the fuel injector to the fuel rail socket are always sought.
What is needed is an arrangement for retaining a fuel injector to a fuel rail socket which minimizes or eliminates one or more of the shortcomings set forth above.
Briefly described, a fuel injector retention arrangement is provided for retaining a fuel injector to a fuel rail socket of a fuel rail where the fuel injector has a fuel injector upper housing which defines a fuel inlet to the fuel injector, the fuel rail socket has a fuel rail socket body, and the fuel rail has a fuel rail volume which receives pressurized fuel. The fuel injector retention arrangement includes a fuel rail socket interior space defined within the fuel rail socket body such that the fuel rail socket interior space extends into the fuel rail socket body along a fuel rail socket axis from a fuel rail socket end surface, the fuel rail socket interior space being in fluid communication with the fuel rail volume; a fuel injector retention flange extending radially outward from the fuel injector upper housing such that the fuel injector retention flange is disposed within the fuel rail socket interior space and such that the fuel inlet is in fluid communication with the fuel rail socket interior space; a fuel rail socket slot extending radially from the fuel rail socket interior space to a fuel rail socket exterior surface and also extending axially to the fuel rail socket end surface; a fuel rail socket retention groove which extends radially outward from the fuel rail socket interior space; and a retainer which is forked, thereby including 1) a retainer first leg located between the fuel injector retention flange and the fuel rail socket end surface and extending through the fuel rail socket slot and 2) a retainer second leg located between the fuel injector retention flange and the fuel rail socket end surface and extending through the fuel rail socket slot, the retainer first leg and the retainer second leg being connected to each other at one end by a retainer base, the retainer first leg having a first retainer lobe which is convex and which extends part way into the fuel rail socket retention groove and part way into the fuel rail socket interior space, thereby supporting the fuel injector retention flange thereon and retaining the fuel injector to the fuel rail socket and the retainer second leg having a second retainer lobe which is convex and which extends part way into the fuel rail socket retention groove and part way into the fuel rail socket interior space, thereby supporting the fuel injector retention flange thereon and retaining the fuel injector to the fuel rail socket.
Another fuel injector retention arrangement includes a fuel rail socket interior space defined within the fuel rail socket body such that the fuel rail socket interior space extends into the fuel rail socket body along a fuel rail socket axis, the fuel rail socket interior space being in fluid communication with the fuel rail volume; a fuel injector retention flange extending radially outward from the fuel injector upper housing such that the fuel injector retention flange is disposed within the fuel rail socket interior space and such that the fuel inlet is in fluid communication with the fuel rail socket interior space; a fuel rail socket slot extending radially from the fuel rail socket interior space to a fuel rail socket exterior surface; a fuel rail socket retention groove which extends radially outward from the fuel rail socket interior space; and a retainer which is forked, thereby including 1) a retainer first leg located adjacent to the fuel injector retention flange and extending through the fuel rail socket slot and 2) a retainer second leg located adjacent to the fuel injector retention flange and extending through the fuel rail socket slot, the retainer first leg and the retainer second leg being connected to each other at one end by a retainer base, the retainer first leg having a first retainer lobe which is convex and which extends part way into the fuel rail socket retention groove and part way into the fuel rail socket interior space, thereby supporting the fuel injector retention flange thereon and retaining the fuel injector to the fuel rail socket and the retainer second leg having a second retainer lobe which is convex and which extends part way into the fuel rail socket retention groove and part way into the fuel rail socket interior space, thereby supporting the fuel injector retention flange thereon and retaining the fuel injector to the fuel rail socket.
A method of assembling the fuel injector retention arrangements includes positioning the fuel injector retention flange within the fuel rail socket interior space; from an initial form, elastically deforming the retainer first leg and the retainer second leg toward each other; positioning the retainer in the fuel rail socket interior space by translating the retainer along the fuel rail socket axis while the retainer first leg and the retainer second leg are elastically deformed toward each other; and after positioning the retainer in the fuel rail socket interior space, allowing the retainer first leg and the retainer second leg to rebound to the initial form, thereby causing the first retainer lobe to extend into the fuel rail socket retention groove and also causing the second retainer lobe to extend into the fuel rail socket retention groove.
The arrangements and methods described herein are simple and economical to produce and use and provides for convenient assembly along the fuel rail socket axis. Furthermore, the retainer snapping into the fuel rail socket retention groove provides robust retention of the fuel injectors and also provides inherent retention of the retainer, thereby requiring no additional features to prevent unintended removal, translation, or rotation of the retainer. Also furthermore, the fuel injector retention arrangements may allow for the fuel rail sockets to be shortened in the direction of the fuel rail socket axis which is beneficial for packaging.
This invention will be further described with reference to the accompanying drawings in which:
Reference will first be made to
With continued reference to
Fuel rail socket 26 has a fuel rail socket body 32 with a fuel rail socket interior space 34 defined therein. Fuel rail socket interior space 34 extends into fuel rail socket body 32 along a fuel rail socket axis 36 from a fuel rail socket end surface 37 of a fuel rail socket open end 38 to a fuel rail socket closed end 40 such that fuel rail socket interior space 34 is stepped, thereby defining a fuel rail socket shoulder 42 therein which faces toward fuel rail socket open end 38. Fuel rail socket 26 is fixed to fuel rail 20, by way of non-limiting example only, by welding or brazing or by being formed integrally therewith as a single piece of material. Fluid communication between fuel rail volume 24 and fuel rail socket interior space 34 is provided by a fuel passage 44 which extends from fuel rail volume 24 to fuel rail socket interior space 34 through fuel rail 20 and fuel rail socket body 32.
Features of fuel rail socket 26 which interact with a retainer 45 which retains fuel injector 22 to fuel rail socket 26 will now be described. A first fuel rail socket slot 46 extends radially from fuel rail socket interior space 34 to a fuel rail socket exterior surface 48 of fuel rail socket 26 where fuel rail socket exterior surface 48 extends around the entire periphery of fuel rail socket 26. First fuel rail socket slot 46 also extends axially, i.e. parallel to fuel rail socket axis 36, to fuel rail socket end surface 37. By way of non-limiting example only, first fuel rail socket slot 46 may extend about 25° to about 35° around fuel rail socket end surface 37. A second fuel rail socket slot 50 extends radially from fuel rail socket interior space 34 to fuel rail socket exterior surface 48 such that second fuel rail socket slot 50 is diametrically opposed to first fuel rail socket slot 46. Second fuel rail socket slot 50 also extends axially, i.e. parallel to fuel rail socket axis 36, to fuel rail socket end surface 37. By way of non-limiting example only, second fuel rail socket slot 50 may extend about 25° to about 35° around fuel rail socket end surface 37.
In addition to first fuel rail socket slot 46 and second fuel rail socket slot 50 which interface with retainer 45, fuel rail socket 26 also includes a fuel rail socket retention groove 52 which extends radially outward from fuel rail socket interior space 34 toward fuel rail socket exterior surface 48, but does not extend all the way to fuel rail socket exterior surface 48, i.e. fuel rail socket retention groove 52 extends radially outward from fuel rail socket interior space 34 only part way into fuel rail socket body 32 except at first fuel rail socket slot 46 and second fuel rail socket slot 50 as will be described in greater detail later. Fuel rail socket retention groove 52 extends axially, i.e. in a direction parallel to fuel rail socket axis 36 from a fuel rail socket retention groove upper surface 52a to a fuel rail socket retention groove lower surface 52b such that fuel rail socket retention groove upper surface 52a and fuel rail socket retention groove lower surface 52b are each traverse to fuel rail socket axis 36 and may be perpendicular to fuel rail socket axis 36 as shown in the figures. Fuel rail socket retention groove 52 extends radially outward to a fuel rail socket retention groove radially outer surface 52c which joins fuel rail socket retention groove upper surface 52a to fuel rail socket retention groove lower surface 52b and may be parallel to fuel rail socket axis 36 as shown in the figures. As illustrated herein, fuel rail socket retention groove 52 includes a fuel rail socket retention groove first portion 52d located between first fuel rail socket slot 46 and second fuel rail socket slot 50 and also includes a fuel rail socket retention groove second portion 52e located between first fuel rail socket slot 46 and second fuel rail socket slot 50 such that first fuel rail socket slot 46 and second fuel rail socket slot 50 separate fuel rail socket retention groove first portion 52d from fuel rail socket retention groove second portion 52e. Also as illustrated herein, fuel rail socket retention groove first portion 52d may extend from where first fuel rail socket slot 46 meets fuel rail socket exterior surface 48 to where second fuel rail socket slot 50 meets fuel rail socket exterior surface 48 and fuel rail socket retention groove second portion 52e may extend from where first fuel rail socket slot 46 meets fuel rail socket exterior surface 48 to where second fuel rail socket slot 50 meets fuel rail socket exterior surface 48. Alternatively, but not shown, fuel rail socket retention groove first portion 52d may extend only from where first fuel rail socket slot 46 meets fuel rail socket interior space 34 to where second fuel rail socket slot 50 meets fuel rail socket interior space 34 and fuel rail socket retention groove second portion 52e may extend only from where first fuel rail socket slot 46 meets fuel rail socket interior space 34 to where second fuel rail socket slot 50 meets fuel rail socket interior space 34.
Fuel injector 22 includes a fuel injector upper housing 54 which is received coaxially within fuel rail socket interior space 34 and which defines a fuel inlet 56 to fuel injector 22 which receives fuel from fuel rail socket interior space 34. Fuel injector upper housing 54 includes a fuel injector retention flange 58 which extends radially outward therefrom and which is disposed within fuel rail socket interior space 34 such that fuel inlet 56 is in fluid communication with fuel rail socket interior space 34. Fuel injector retention flange 58 is annular in shape and includes a fuel injector retention flange upper surface 58a which faces toward fuel rail socket closed end 40 and also includes a fuel injector retention flange lower surface 58b which faces toward fuel rail socket open end 38. A sealing arrangement 59, which may include an O-ring and one or more backup rings as illustrated in the figures, is supported by fuel injector retention flange upper surface 58a thereby providing a fuel-tight seal between fuel injector upper housing 54 and fuel rail socket 26 in order to prevent fuel from escaping to the environment from fuel rail socket interior space 34. Fuel injector retention flange lower surface 58b may be spherical or conical in shape as illustrated in the figures in order to accommodate angular misalignment between fuel injector 22 and fuel rail socket axis 36, as will be described in greater detail later, such that fuel injector retention flange lower surface 58b engages retainer 45, also as will be described in greater detail later. As used herein, the term spherical is intended to include a portion of the surface of a sphere and conical is intended to include a portion of the lateral surface of a cone.
Retainer 45 is forked, thereby including a retainer first leg 60 and a retainer second leg 62 such that one end of retainer first leg 60 and one end of retainer second leg 62 are connected to each other by a retainer base 64 where retainer first leg 60, retainer second leg 62, and retainer base 64 are preferably made of a single, unitary piece of material which may preferably be metal such as steel. Retainer first leg 60 and retainer second leg 62 are each located axially between fuel injector retention flange 58 and fuel rail socket end surface 37 and each extend through first fuel rail socket slot 46 and through second fuel rail socket slot 50. In order to secure retainer 45 to fuel rail socket 26, retainer first leg 60 includes a first retainer lobe 60a which is convex facing toward fuel rail socket retention groove radially outer surface 52c of fuel rail socket retention groove first portion 52d and which extends part way into fuel rail socket retention groove first portion 52d and part way into fuel rail socket interior space 34. Similarly, retainer second leg 62 includes a second retainer lobe 62a which is convex is convex facing toward fuel rail socket retention groove radially outer surface 52c of fuel rail socket retention groove second portion 52e and which extends part way into fuel rail socket retention groove second portion 52e and part way into fuel rail socket interior space 34. The portions of first retainer lobe 60a and second retainer lobe 62a which extend into fuel rail socket interior space 34 engage fuel injector retention flange lower surface 58b and thereby support fuel injector retention flange 58 thereon and retain fuel injector 22 to fuel rail socket 26.
Retainer first leg 60 terminates at a retainer first leg free end 60b which is distal from retainer base 64, and similarly, retainer second leg 62 terminates at a retainer second leg free end 62b which is distal from retainer base 64. Retainer first leg free end 60b and retainer second leg free end 62b are separated from each other as illustrated in
The portion of retainer first leg 60 which is between retainer base 64 and first retainer lobe 60a extends part way into fuel rail socket retention groove first portion 52d and part way into first fuel rail socket slot 46 and the portion of retainer first leg 60 which is between first retainer lobe 60a and retainer first leg free end 60b extends part way into fuel rail socket retention groove first portion 52d and part way into second fuel rail socket slot 50. Similarly, the portion of retainer second leg 62 which is between retainer base 64 and second retainer lobe 62a extends part way into fuel rail socket retention groove second portion 52e and part way into first fuel rail socket slot 46 and the portion of retainer second leg 62 which is between second retainer lobe 62a and retainer second leg free end 62b extends part way into fuel rail socket retention groove second portion 52e and part way into second fuel rail socket slot 50. It should be noted that if fuel rail socket retention groove first portion 52d extends only from where first fuel rail socket slot 46 meets fuel rail socket interior space 34 to where second fuel rail socket slot 50 meets fuel rail socket interior space 34 and fuel rail socket retention groove second portion 52e extends only from where first fuel rail socket slot 46 meets fuel rail socket interior space 34 to where second fuel rail socket slot 50 meets fuel rail socket interior space 34, then only first retainer lobe 60a and second retainer lobe 62a extend into fuel rail socket retention groove 52.
In order to accommodate angular misalignment between fuel injector 22 and fuel rail socket axis 36 while allowing fuel injector retention flange lower surface 58b to maintain contact with both retainer first leg 60 and retainer second leg 62, retainer first leg 60 has a retainer first leg surface 60d which is spherical or conical and which engages fuel injector retention flange lower surface 58b, thereby supporting fuel injector retention flange 58. Retainer first leg surface 60d is located radially outward from first retainer recess 60c relative to fuel rail socket axis 36. Similarly, retainer second leg 62 has a retainer second leg surface 62d which is spherical or conical and which engages fuel injector retention flange lower surface 58b, thereby supporting fuel injector retention flange 58. It should be noted that if fuel injector retention flange lower surface 58b is conical, then retainer first leg surface 60d a retainer second leg surface 62d are each spherical and if retainer first leg surface 60d and retainer second leg surface 62d are each conical, then fuel injector retention flange lower surface 58b is spherical. However, if fuel injector retention flange lower surface 58b is spherical, retainer first leg surface 60d and retainer second leg surface 62d may also be spherical. In this way, fuel injector 22 can be angularly misaligned with fuel rail socket axis 36 while maintaining contact of fuel injector retention flange lower surface 58b with both retainer first leg 60 and retainer second leg 62. Retainer second leg surface 62d is located radially outward from second retainer recess 62c relative to fuel rail socket axis 36.
In order to assemble fuel injector 22 to fuel rail socket 26, fuel injector upper housing 54 is inserted into fuel rail socket interior space 34 by translation along fuel rail socket axis 36 as indicated by arrow 66 in
Fuel injector retention arrangement 30 as described, utilizes retainer 45 which is a one-piece element which is simple and economical to produce and provides for convenient assembly along fuel rail socket axis 36. Furthermore, retainer 45 snapping into fuel rail socket retention groove first portion 52d and fuel rail socket retention groove second portion 52e provides robust retention of fuel injectors 22 and also provides inherent retention of retainer 45, thereby requiring no additional features to prevent unintended removal, translation, or rotation of retainer 45. Also furthermore, fuel injector retention arrangement 30 may allow for fuel rail sockets 26 to be shortened in the direction of fuel rail socket axis 36 which is beneficial for packaging.
While this invention has been described in terms of the preferred embodiments thereof, it is not intended to be so limited, but rather only to the extent set forth in the claims that follow.
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Entry |
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Disclosed Anonymously, Unique Fuel Injector Suspension Design for High Pressure Gasoline Direct Injection, Research Disclosure, published May 2014 in paper journal, published digitally Mar. 31, 2014, Research Disclosure database No. 601008, Research Disclosure, Questel Ireland Ltd, Killeman, Kilmaine, County Mayo,Ireland. |
Number | Date | Country | |
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20210079877 A1 | Mar 2021 | US |