Automotive fuel systems with graphene-incorporated elastomeric seals

Abstract

A capless fuel unit having an elongated tubular, cylindrical housing open at each end, the housing defining longitudinally spaced first and second fluid ports. A first flapper valve is associated with the first fluid port and a second flapper valve is associated with the second fluid port, the flapper valves being movable between open and closed positions and resiliently biased toward their respective closed positions. A pressure relief valve is at least partially contained within the interior of the flapper valve. An elastomeric seal arrangement incorporating graphene derivative material is disposed within the housing proximate the flapper valve to resist hydrocarbon emissions from fuel vapor escaping the unit to the atmosphere.

Description

[Technical field]

[0001] The present invention relates generally to fuel systems that are subject to hydrocarbon permeation. More specifically, the present invention teaches graphene-incorporated elastomeric seals incorporated into either vehicle fuel delivery, storage or recovery systems.

[0002] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to USSN 63 / 340,062, filed May 10, 2022. [Background technology]

[0003] Automotive fuel seals are known in the art that can be used to help reduce the permeation of hydrocarbons from different grades of gasoline within a vehicle fuel system. Strict government regulations associated with increased awareness of climate issues have led to increased control over automotive fuel emissions. In the late 1990s, U.S. automotive suppliers were forced to begin implementing ORVR (On-Board Refuelling Vapor Recovery) systems to meet EPA requirements for reducing automotive hydrocarbon emissions. The use of low permeability elastomeric seals and materials is a key component in controlling emissions in ORVR systems.

[0004] One of the most common elastomeric materials used in vehicle fuel systems to help reduce fuel permeation is FKM. This material is found in fuel pump thread ring seals, quick connector O-rings, fueling restriction vent valve / combo valve seals, inlet check valve seals, and fuel tank cap or capless seals. All of these parts contribute and add to the total amount of hydrocarbon emissions of a vehicle that are limited by government regulations. By adding graphene to FKM or other elastomers such as FVMQ or NBR, the amount of hydrocarbons that permeate through that material is reduced. FVMQ and NBR are not typically used to reduce permeation, but are often used as secondary seals to aid in other properties such as low temperature sealing. When graphene is applied to the secondary seal along with the primary seal, it only serves to improve the overall permeation of that subassembly.

[0005] More specifically, the seals used in a capless refueling system typically include one or two door seals along with one or two body or pipe seals. Additionally, there may be some type of pressure relief seal designed to allow fuel vapor pressure to escape from the fuel tank under extreme conditions. Such seals are generally constructed of FKM to reduce the amount of vapor emissions located inside the fuel filler pipe after refueling or even under normal vehicle operating conditions. As described in connection with the present invention, the addition of graphene to these seals reduces the amount of fuel vapor emissions exiting the top of the fuel filler pipe.

[0006] Graphene is a two-dimensional planar nanomaterial consisting of sp2 bonded carbon atoms packed into a honeycomb lattice. Many of the material properties that make graphene advantageous, such as high tensile strength, high thermal and electrical conductivity, and chemical and permeation resistance, stem from the unique bonding structure of planar graphene. However, the application of graphene on a macroscopic scale for applications such as in the automotive industry remains a challenge. Summary of the Invention [Means for solving the problem]

[0007] The present invention describes the use of graphene derivative elastomer composite systems to provide high quality automotive fuel system seals with improved mechanical and barrier properties. In particular, this involves the use of one or more elastomer seals incorporating graphene derivatives that can be integrated into a capless unit associated with a fuel filler tube.

[0008] In a non-limiting application, the capless fuel filling system includes an elongated tubular and cylindrical housing open at each end, typically constructed from a plastic material for inexpensive and durable construction.

[0009] First and second axially spaced apart fluid ports are formed in the housing, with the first fluid port disposed adjacent the inlet of the housing and the second fluid port disposed adjacent the outlet of the housing. The fluid ports are substantially axially aligned with one another and are sized to receive a standard fuel fill nozzle (not shown). Additionally, the design of the fluid ports in the capless unit is adapted to prevent the insertion of an unauthorized hose (such as for the theft of gasoline from the tank).

[0010] A flapper valve is associated with each of the fluid ports and is movable between an open position and a closed position. A spring biases each of the valves toward the closed position. Both flapper valves move away from the housing inlet and toward the housing outlet when moving from a closed position to an open position, such as in response to the insertion of a fuel filler pipe or nozzle. In this manner, a fuel fill nozzle inserted into the inlet end of the housing passes through both the first and second fluid ports and, in doing so, pivots the first and second flapper valves from the open position to the closed position.

[0011] As further shown, the capless unit includes a seal arrangement incorporating graphene derivatives, including each pair of outer annular body seals, along with inner annular door seals and pressure relief seals associated with each of the first and second fluid ports.

[0012] Another contemplated use of the present invention includes a graphene derivative material incorporated into an elastomeric seal associated with a quick connector device for a fuel system including a male connector defining a first body and a female connector defining a second body, the male connector mated with the female connector to define a fluid communication path. The seal arrangement incorporated into at least one of the quick connector bodies resists hydrocarbon emissions from fuel vapors escaping the unit to the atmosphere. [Brief description of the drawings]

[0013] Reference is now made to the accompanying drawings when read in conjunction with the following detailed description, in which like reference characters refer to like parts throughout the several views.

[0014] [Figure 1] FIG. 1 is a perspective view of a vehicle capless unit incorporating an elastomeric seal arrangement incorporating graphene derivative material, according to one non-limiting embodiment of the present invention.

[0015] [Diagram 2] FIG. 2 is a top cross-sectional view of the vehicle capless unit shown in FIG. 1, showing the internal arrangement of the body seal, pressure relief seal, and door seal.

[0016] [Diagram 3] FIG. 3 is a further cross-sectional view similar to FIG. 2, further illustrating an elastomeric seal arrangement for resisting the discharge of hydrocarbon vapor emissions to the atmosphere.

[0017] [Figure 4]1 is an elevational view of a fluid quick connector device incorporating graphene derivatives into an elastomeric seal according to a further embodiment of the present invention.

[0018] [Diagram 5] 1 is a cross-sectional view of a fluid connector device showing a tube having an annularly extending protrusion in an intermediate engagement position with a retainer latch;

[0019] [Figure 6] FIG. 6 is a further continued plan cross-sectional view of the fluid connector device of FIGS. 4-5, showing a tube attached through a latch and held open by the side of a separate verification member aligning with the annular bead, representing the tube in an attached position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] With reference to the accompanying drawings, the present invention discloses a capless fuel unit or assembly incorporating an elastomeric seal arrangement, for example, with graphene derivatives integrated therein. In particular, Figure 1 provides a perspective view of a vehicle capless unit, generally at 10, incorporating an elastomeric seal arrangement incorporating graphene derivatives, according to one non-limiting embodiment of the present invention.

[0021] FIG. 2 further provides a top cross-sectional view of the vehicle capless unit shown in FIG. 1 showing the internal arrangement of the body seal, pressure relief seal, and door seal, followed by FIG. 3 showing a further cross-sectional view similar to FIG. 2, further showing the arrangement of elastomeric seals for resisting emission of hydrocarbon vapor emissions to the atmosphere.

[0022] Referring again to the accompanying drawings, there is shown an elongated tubular, cylindrical housing 12 open at each end having a plastic or polymeric construction, including but not limited to nylon, which in the illustrated embodiment is fitted with a fuel filler tube 14 (see FIG. 3) such that it is exposed to the presence of hydrocarbon fuel vapors emanating from a connected fuel tank (not shown).

[0023] As further shown, the housing defines first and second longitudinally spaced fluid ports corresponding to positions of each of the first and second flapper valves 16 and 18, which are movable between open and closed positions. In one non-limiting configuration, each of the first and second flapper valves further includes first and second valve portions secured to one another by a snap fit. Also shown are a pair of springs 20 and 22 that resiliently bias the flapper valves 16 / 18 toward their respective closed positions.

[0024] 2-3 are first and second pressure relief valves 24, 26 corresponding to first and second flapper valves 16, 18. As shown, the pressure relief valves are shown housed within the flapper valves.

[0025] The present invention further illustrates an arrangement of elastomeric seals incorporating graphene derivative material disposed within the housing proximate the flapper valve to resist hydrocarbon emissions from fuel vapors escaping the unit to the atmosphere. As shown, these include a first pressure relief seal 28 and a second pressure relief seal 30, respectively, located at the pressure relief valves 24 / 26.

[0026] Also included are first and second elastomeric door seals 32 and 34 corresponding in position with the first and second flapper valves 16 and 18. Additional body seals 36 and 38 are configured within first and second axially spaced apart locations of the cylindrical housing. The graphene derivative-incorporated elastomeric seal arrangement functions to resist the emission of hydrocarbon vapor emissions to the atmosphere.

[0027] Referring now to Figure 4, an elevational view of a fluid coupling in which some or all of the elastomeric sealing components incorporate graphene derivative material is shown at 100, according to a further embodiment of the present invention. The coupling has a housing 102 having a female portion and an interconnected insertion tube 104. The tube 104 also includes a bead 106 adjacent its end that extends around the circumference of the cylindrical tube 104, the bead extending radially outward (see subsequent Figures 5-6).

[0028] The housing female portion 102 incorporates a through hole 108 that places the female portion in communication with a connected male portion 110, the through hole receiving a tube 104 having an annularly extending bead 106. The female portion 102 and male portion 110 of the quick connect housing may be constructed of any suitable material, typically including, but not limited to, plastic, and it is further envisioned that an additional hose or conduit (not shown) is secured over the reduced diameter male portion 110 such that the through hole places the attached tube 104 in communication with the outlet of the male portion 110.

[0029] A heat staking operation is used to secure a tubular outer spacer 118 within the female portion of the housing proximate the receiving ends of the tube 104 and annular bead 106. The spacer 118 is provided in combination with an arrangement of seals 120 and 122 and an intervening annular support 124 compressed between the outer spacer 118 and an inwardly facing annular shoulder location 126 to provide a pressurized seal support between the female portion 102 and the male portion 110 of the housing. As previously mentioned, the material construction of the seals 120 / 122 may incorporate graphene derivative material to resist hydrocarbon emissions from fuel vapors to the atmosphere.

[0030] The heat staking can be provided according to any number of angular offsets, including but not limited to placing the heat stake locations at 60 degree offsets (six total), as well as providing any other shape or profile. In any application, the heat staking ensures that the outer spacer is retained within the body head, avoiding instances of the outer spacer axially separating, such as after a tube and bead separation operation using the methods described below.

[0031] The female housing portion 102 further integrates an insertion end 128 (which is shown in cross section in the remaining figures) having a corresponding profile for each of the latch 130 and verification member 132. The latch and verification member are provided in a stacked arrangement and mounted within the female portion 102 in communication with the insertion direction of the tube 104 through the internal through-hole 108, which are further arranged in a stacked arrangement and supported within the end 128 through an upper located mounting slot (see inner extending edge profile 134). The insertion end 128 further has opposing side cutout profiles, one of which is shown by a peripheral edge 136 in FIG. 1, which seats the extended pair of extending sides or legs of each of the latch 130 and verification member 132 such that each of the latch and verification members presents a generally "U" shape that surrounds on three sides the cross-sectional profile of the tube 14 into which it is inserted.

[0032] Although not limited to any of the separate embodiments previously described in each of Figures 1-3 and 4-6, the group of graphene derivatives may further include, but are not limited to, any of graphene, single layer graphene, few layer graphene, graphene oxide, reduced graphene oxide, and functionalized graphene. The loading concentration of the graphene derivatives may vary from 0.1 to 60 weight percent. The sealing material may include, but are not limited to, any of fluorinated carbon-based synthetic rubber (FKM), fluorosilane or silicone rubber (FVMQ), thermoplastic vulcanizate (TPV), ethylene propylene diene monomer (EPDM), hydrogenated nitrile butadiene rubber (HNBR), or nitrile butadiene rubber (NBR).

[0033] Having described the present invention, other and additional preferred embodiments will become apparent to those skilled in the art without departing from the scope of the appended claims. It is to be further understood that the detailed description and drawings support this disclosure, the scope of which is defined by the appended claims. Although certain best modes and other embodiments for carrying out the claimed teachings have been described in detail, there are various alternative designs and embodiments for carrying out the disclosure as defined by the appended claims.

[0034] It is further understood that the foregoing disclosure is not intended to limit the present disclosure to the exact form or particular field of use disclosed. Thus, various alternative embodiments and / or modifications to the present disclosure, whether expressly described or implied herein, are possible in light of the present disclosure. Having thus described an embodiment of the present disclosure, those skilled in the art will recognize that changes can be made in form and detail without departing from the scope of the present disclosure. Thus, the present disclosure is limited only by the scope of the claims.

[0035] In the above specification, the present disclosure has been described with reference to certain embodiments. However, as will be appreciated by those skilled in the art, the various embodiments disclosed herein can be modified or implemented in various other ways without departing from the spirit and scope of the present disclosure. Thus, this description should be considered as illustrative and is for the purpose of teaching those skilled in the art how to make and use the various embodiments of the present disclosure. It should be understood that the forms of the disclosure shown and described herein should be interpreted as representative embodiments. What is typically shown and described herein may be replaced with equivalent elements, materials, processes or steps. Furthermore, certain features of the present disclosure can be utilized independently of the use of other features, as will become apparent to those skilled in the art after having the benefit of this description of the present disclosure. The terms "including," "comprising," "incorporating," "consisting of," "have," "is," and the like, used to describe and claim the present disclosure, are intended to be interpreted in a non-exclusive manner, i.e., to allow for the presence of items, parts, or elements not expressly described. References to the singular are also to be construed as relating to the plural.

[0036] Furthermore, the various embodiments disclosed herein should be construed in an illustrative and explanatory sense, and should not be construed as limiting the present disclosure in any way. Any references to joints (e.g., attached, fixed, coupled, connected, etc.) are used only to aid the reader in understanding the present disclosure, and do not create limitations with respect to the position, orientation, or use of the systems and / or methods specifically disclosed herein. Thus, any reference to joints, if any, should be interpreted broadly. Moreover, such references to joints do not necessarily imply that two elements are directly connected to each other.

[0037] Additionally, all numerical terms, such as, but not limited to, "first," "second," "third," "primary," "secondary," "main," or any other conventional and / or numerical term, should also be interpreted merely as identifiers to aid the reader in understanding the various elements, embodiments, variations and / or modifications of the disclosure, and in no way create any limitation, particularly with respect to the order or priority of any element, embodiment, variation and / or modification, relative to or in comparison to another element, embodiment, variation and / or modification.

[0038] It will also be understood that one or more of the elements shown in the drawings / diagrams may also be implemented in a more separated or integrated manner, or may be removed or rendered inoperative in certain cases, as may be useful depending on the particular application. Additionally, any signal hatches in the drawings / diagrams should be considered merely illustrative, not limiting, unless otherwise noted.

Claims

1. 1. A capless fuel unit, comprising: an elongated tubular, cylindrical housing open at each end, the housing defining first and second longitudinally spaced fluid ports; a first flapper valve associated with the first fluid port and a second flapper valve associated with the second fluid port, the first flapper valve and the second flapper valve being movable between an open position and a closed position and being resiliently biased toward their respective closed positions; a pressure relief valve housed within each of said flapper valves; an arrangement of elastomer seals incorporating graphene derivatives disposed within the housing proximate the flapper valve to resist hydrocarbon emissions from fuel vapors escaping from the unit to the atmosphere; A capless fuel unit comprising:

2. The apparatus of claim 1 , wherein the elastomeric seal further comprises first and second pressure relief seals.

3. 10. The apparatus of claim 1, further comprising first and second springs biasing the first and second flapper valves toward a closed position.

4. The apparatus of claim 1 , wherein the elastomeric seal further comprises a door seal surrounding the flapper valve.

5. The apparatus of claim 1 , wherein the elastomeric seal further comprises a body seal configured within first and second axially spaced locations of the cylindrical housing.

6. The device of claim 1 , wherein each of the first and second flapper valves further comprises first and second valve portions secured to one another by a snap fit.

7. 10. The device of claim 1, wherein the graphene derivative further comprises at least one selected from the group consisting of single layer graphene, few layer graphene, graphene oxide, reduced graphene oxide, and functionalized graphene.

8. 10. The apparatus of claim 1, wherein the elastomeric seal further comprises one of a fluorinated carbon based synthetic rubber, a fluorosilicone rubber, a thermoplastic vulcanizate, an ethylene propylene diene monomer, a hydrogenated nitrile butadiene rubber, or a nitrile butadiene rubber.

9. 1. A quick connector device for a fuel system, comprising: a male connector defining a first body and a female connector defining a second body, the male connector engaged with the female connector to define a fluid communication path; an elastomeric seal arrangement incorporated within at least one of the bodies, at least one of the elastomeric seals incorporating graphene for said resistance to hydrocarbon emissions from fuel vapors escaping from the unit to the atmosphere; A quick connector device comprising:

10. 10. The quick connector of claim 9, wherein the graphene further comprises a graphene derivative comprising at least one selected from the group consisting of single layer graphene, few layer graphene, graphene oxide, reduced graphene oxide, and functionalized graphene.

11. 10. The quick connector of claim 9, wherein the elastomeric seal further comprises one of a fluorinated carbon synthetic rubber, a fluorosilicone rubber, a thermoplastic vulcanizate, an ethylene propylene diene monomer, a hydrogenated nitrile butadiene rubber, or a nitrile butadiene rubber.

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