GB2578466A

GB2578466A - Seal assembly for pressurised fuel systems

Info

Publication number: GB2578466A
Application number: GB1817610.7A
Authority: GB
Inventors: Salamon Csaba; Paul Doherty Raymond
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2018-10-29
Filing date: 2018-10-29
Publication date: 2020-05-13
Anticipated expiration: 2038-10-29
Also published as: GB2578466B; GB201817610D0

Abstract

A seal assembly for use in a fuel tank assembly of a plug-in hybrid electric vehicle. The seal assembly comprises a sealing element (152, Fig.10), and a guide element (150) to which the sealing element is fixed. The sealing element is movable relative to the guide element to permit a degree of movement of a nozzle 120 when the nozzle is inserted within the sealing element, without breaking the seal therebetween. The guide element limits movement of the nozzle in at least one direction. Preferably, the guide element is generally rectangular and includes opposing side walls (64, Fig.5a) and opposing curved end walls (65), and consequently allows only a nozzle for a specific fuel type. The guide opening may have a central axis that is misaligned form the central axis of the sealing element. This misalignment could be adjustable when the nozzle is inserted. A retaining clip 148 may be present to fix the assembly into a fuel filler neck assembly. A second seal 138, vapour cavity 140, and vapour release valve may also be present.

Description

SEAL ASSEMBLY FOR PRESSURISED FUEL SYSTEMS

TECHNICAL FIELD

The present invention relates to a seal assembly for use in a fuel filler neck assembly for a fuel tank to prevent fuel vapour release to the external environment from the sealed fuel tank during refuelling. The invention is particularly suitable for use in the filling neck of a fuel filler neck assembly for an internal combustion engine system of a plug-in hybrid electric vehicle. Aspects of the invention relate to a seal assembly, a retainer clip for retaining the seal assembly within a fuel filler neck assembly, a fuel filler neck assembly comprising the seal assembly and a vehicle comprising the fuel filler neck assembly.

BACKGROUND

Plug-in hybrid electric vehicles (PHEV) incorporate both a main and a backup system for allowing fuel vapour release from the sealed fuel tank. In both systems, the fuel vapour is released to a carbon canister, where it is captured and can be re-used. If the fuel tank isolation valve of the main vapour release system is faulty, the backup system allows vapour release to the carbon canister during refuelling.

The backup system incorporates a dual seal configuration, whereby the fuel nozzle passes through an opening in a flexible first sealing element, before a second sealing element is opened by the action of the fuel nozzle. The vapour from the fuel tank is released into an intermediate chamber which is defined between the first and second sealing elements. Vapour exits the intermediate chamber through an umbrella valve and flows onward towards the carbon canister.

There is a risk that discrepancies between the size of the fuel nozzle and the first sealing element results in vapour release into the atmosphere, which reduces the efficiency of and increases the pollution from the vehicle. To overcome this, the nozzle opening of the first sealing element is configured to create an airtight seal with the fuel nozzle, so no vapour can escape However, a very tight seal enables little movement of the fuel nozzle during refuelling and if a user does not insert the fuel nozzle into the neck at the correct angle, the second sealing element may not be engaged properly, meaning refuelling cannot occur, and vapour cannot be released. Alternatively, the user may try to begin refuelling, leading to other problems within the system if the nozzle is not properly engaged.

Furthermore, while the second sealing element is dimensioned to discriminate against the wrong fuel nozzle size (and hence prevent mis-fuelling with the wrong type of fuel), it is conceivable that a user, who is used to forcibly inserting the fuel nozzle to achieve a tight seal, may be able to force a larger nozzle through the opening of the flexible first sealing element and attempt to refuel. While the second sealing element will not engage with the wrong nozzle, the first sealing element may be damaged by the larger diameter of the nozzle, leading to vapour escape when refuelling in future.

It is an object of the invention to provide a seal assembly which addresses the shortcomings of the prior art.

SUMMARY OF THE INVENTION

According to an aspect of the invention, there is provided a seal assembly for use in a fuel tank assembly of a plug-in hybrid electric vehicle. The seal assembly comprises a sealing element defining a seal opening for receiving a nozzle of a fuel dispensing system, in use, so as to define a seal therebetween. The sealing assembly also comprises a guide element to which the sealing element is fixed. The sealing element is movable relative to the guide element to permit a degree of movement of the nozzle when the nozzle is dropped down, within the sealing element, without breaking the seal therebetween. The guide element serves to limit movement of the nozzle in at least one direction.

A nozzle is dropped down, or has a drop down function, when released by a user. When released by the user, the weight of the nozzle causes movement from the position in which it was being held by the user to a new position. For example, the nozzle may drop vertically downwardly relative to the first position. The drop down therefore allows the user to 'rest' the nozzle while refueling.

Advantageously, therefore, the seal assembly, and in particular its movement relative to the guide element, reduces the possibility of the seal between the sealing element and the nozzle breaking when the nozzle is dropped down, permitting continued refueling without vapour release. Furthermore, dropping the nozzle down is now less likely to damage the seal assembly. The seal assembly also provides some support to the nozzle by the guide element.

Optionally, the nozzle is received through the sealing element in a first direction. The sealing element may be movable relative to the guide element in at least a second direction. The second direction may be different to the first direction, i.e. the second direction is not the same as the first direction. The guide element may serve to limit movement of the nozzle in each of the second direction and a third direction. The third direction may be different to, i.e. not the same as, the first and/or second directions, and is optionally perpendicular to the second direction.

For example, while each of the first, second, and third directions may be perpendicular, it is also intended that the third direction may be any other direction that is not the first and second directions. Direction is intended to encompass both the concept of a path and the concept of direction as would be used in relation to a vector. That is, that limiting movement in one direction describes either the limitation of movement when moving along an axis, i.e. side-to-side movement or up-and-down movement, or the limitation of movement when moved from one point towards another point, i.e. movement to one side, or movement in only the up or down direction. Thus, while the third direction may exist in a different plane to that of the first and second directions, it may also be oppositely directed to the first or second directions.

Limiting the movement of the sealing element by the guide element further protects the seal formed between nozzle and sealing element, so that the ease of use of the seal assembly is improved. The user is also likely to experience feedback if they attempt to move the sealing element and nozzle too far in one of the directions, prompting them to reduce pressure on the nozzle, and return to the desired positioning. The guide element can be considered to protect a refuelling system in use, by limiting the movement as it does.

The guide element may define a guide opening for receiving the nozzle of the fuel dispensing system and for limiting movement of the nozzle within the sealing element, in use. The guide opening may limit movement of the nozzle within the sealing element in the third direction to a greater extent than in the second direction to enable the nozzle to be dropped down.

Limiting the nozzle's movement in this manner further enhances the seal assembly's use when the nozzle is dropped down. The guide opening can limit the nozzle's movement sufficiently to ensure that the seal is maintained at all times, and that no damage is done to any component of a fuel tank assembly internally of the seal.

Optionally, the guide opening is generally rectangular. The guide opening may include first and second opposed sidewalls which cooperate with the nozzle, in use, to limit movement of the nozzle in one direction. The guide opening may include first and second opposed curved end walls which cooperate with the nozzle, in use, to limit movement of the nozzle in one direction. The guide opening may be shaped to receive only a nozzle for a specific type of fuel.

Guide openings are particularly useful in ensuring that movement of the sealing element is limited to a particular shape. A particularly useful shape is a substantially rectangular shape, having bulged, semi-circular ends. A guide opening having a rectangular shape may be dimensioned to severely restrict the movement of the guide element in one direction, while permitting greater movement in a perpendicular direction. For example, the nozzle may therefore be permitted by the guide element to move up and down, whilst being restricted from side to side movement.

Guide openings, when sized to accommodate only particular nozzle types, also have the advantage of preventing misfuelling.

The guide opening may have a guide opening central axis. The seal opening may have a seal opening central axis. The central axes may be misaligned by a degree of misalignment prior to receiving the nozzle, in use. That is, that the central axes may not be coaxial. The central axes may be parallel. The degree of misalignment may be adjustable, for example when the nozzle is received within the seal opening. Furthermore, the central axes may also be misaligned or aligned with a central axis of further components within a fuel tank assembly.

The sealing element may be configured to deform, and may be configured to deform to permit movement of the nozzle relative to the guide element, in use. By permitting a drop down function, and deforming, the sealing element maintains a predetermined position for receiving the nozzle prior to use, and is able to move comfortably when the nozzle is received. Deformation of the sealing element enables a direct connection between the guide and sealing elements, reducing the possibility of vapour release through the sealing assembly.

The seal opening may comprise a slanted (beveled) internal face for receiving the nozzle, which aids with directing the nozzle and forming a seal.

Optionally, the guide element is manufactured from a material that is mechanically harder than that of the sealing element. The guide element may therefore at least partially protect the sealing element from being struck and damaged by the nozzle when being inserted.

Optionally, the sealing element comprises a circular grommet. The circular grommet may comprise a single item, formed to directly attach to the guide element, surrounding an opening.

The seal assembly may consist of the guide element and sealing element only.

According to another aspect of the invention, there is provided a seal assembly for use in a fuel tank assembly of a plug-in hybrid electric vehicle. The seal assembly comprises a sealing element defining a seal opening for receiving a nozzle of a fuel dispensing system therethrough, in use, so as to define a seal therebetween. The nozzle is received through the seal opening in a first direction. The seal assembly comprises a guide element cooperable with the sealing element. The sealing element is slideable relative to the guide element, in a second direction that is different to the first direction, to permit a degree of movement of the nozzle, within the sealing element, without breaking the seal therebetween. The guide element serves to limit movement of the nozzle in at least one direction.

The seal assembly therefore ensures that the formation of a seal suitable for maintaining fuel vapour within a cavity is not impacted (or is less impacted) by the movement of the nozzle. The slideability of the sealing element relative to the guide element permits movement of the nozzle by the user, allowing a greater flexibility of movement and a greater usability than conventional static seals. The guide element advantageously protects the sealing element, and is useful in ensuring that, while movement of the sealing element is possible, the nozzle is not moved beyond the limits of the system.

Optionally, the guide element limits movement of the nozzle in the first and/or the second direction. The first and second directions may be perpendicular. Optionally, the guide element serves to limit movement of the nozzle in a second direction and a third direction at least. The third direction may be different to the first and second directions.

The guide element may also limit movement of the nozzle in each of three perpendicular directions.

The guide element may comprise front and rear elements for receiving the sealing element therebetween. The front and rear elements may be joined at one end to define a channel for receiving the sealing element and permitting removal of the sealing element.

The front and rear elements are particularly helpful in limiting the movement of the sealing element. The removability of the sealing element by forming an open channel is a particularly useful feature for the maintenance of the assembly in use. Having the option to replace the sealing element ensures an efficient repair process is enabled, as well as a particularly cheap one.

Optionally, the sealing element further comprises a first sealing ring that engages one of the front and rear elements of the guide element so as to define a seal therebetween.

The sealing element may further comprises a second sealing ring that engages the other of the front and rear elements of the guide element so as to define a seal therebetween. The first and second sealing rings may have different diameters, and may be concentrically arranged with the seal opening.

Advantageously, the sealing rings seal the sealing element against the guide element, so that there is no (or at least reduced) potential for vapour escape between the elements.

The guide element may define a guide opening for receiving the nozzle of the fuel dispensing system, in use. The guide opening may be formed in the front or rear element of the guide element. If the sealing assembly incorporates both sealing rings on the sealing element and a guide opening, the sealing rings should have a greater diameter than both the seal opening and the guide opening.

The guide opening may be generally rectangular. The guide opening may include first and second opposed sidewalls which cooperate with the nozzle, in use, to limit movement of the nozzle in one direction. The guide opening may include first and second opposed curved end walls, which cooperate with the nozzle, in use, to limit movement of the nozzle in one direction.

The guide element may be manufactured from a material that is mechanically harder than that of the sealing element.

The sealing element may comprise a lip portion. The lip portion may define the perimeter of the seal opening. The sealing element may comprise a body portion surrounding the lip portion. The body portion may be manufactured from a material that is mechanically harder than that of the lip portion.

The sealing element may be manufactured from a material with a relatively high elasticity. The sealing element may permit movement of the nozzle in the second direction by sliding movement of the sealing element or by deformation of the sealing element. By high elasticity, it is intended to mean that the sealing element is able to deform to receive the nozzle and is able to deform further in response to the movement of the nozzle, without being irreparably altered, or plastically deformed. In other words, the Young's Modulus of the material of the sealing element is low, and/or the yield strength of the material is also low, especially when compared with the values of these parameters for the material from which the guide element is manufactured. In this case, the seal opening may have a smaller diameter than a nozzle intended to be inserted through it, since the seal will deform to expand the opening to accommodate the nozzle.

According to another aspect of the invention, there is provided a retainer clip configured to fix the seal assembly as described above within a fuel filler neck of a vehicle.

According to another aspect of the invention, there is provided a fuel filler neck assembly for a vehicle. The fuel filler neck assembly comprises the seal assembly as described above.

The seal assembly may be fixed in place against a shoulder of the fuel filler neck by the retainer clip described above.

Optionally, the fuel filler neck assembly further comprises a second seal for a fuel tank of the fuel tank assembly. The second seal may be configured to provide access to the fuel tank when opened by the nozzle. The seal assembly and second seal may be mounted in a fuel filler neck of the fuel filler neck assembly. The seal assembly and second seal may define a vapour cavity therebetween from which vapour may be released via a vapour release valve in the fuel filler neck. In use, when a seal is formed between the nozzle and the seal assembly, and when the second seal is open, the vapour cavity may be pressurized and vapour may be released from the fuel tank into the vapour cavity for release via the valve.

According to another aspect of the invention, there is provided a vehicle comprising the fuel filler neck assembly as described above.

The vehicle may comprise an upwardly facing surface. The fuel filler neck assembly may be oriented on the vehicle such that, in use, the nozzle is inserted into the fuel filler neck assembly through the upwardly facing surface of the vehicle. The seal assembly may limit movement of the nozzle in at least two substantially horizontal directions.

Optionally, the vehicle comprises a sideward facing surface. The fuel filler neck assembly may be oriented on the vehicle such that, in use, the nozzle is inserted into the fuel filler neck assembly through the sideward facing surface of the vehicle. The seal assembly may limit movement of the nozzle in at least one substantially horizontal direction and at least one substantially vertical direction.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a vehicle incorporating a fuel filler neck assembly of the present invention; Figure 2 is a cross-sectional, side view of the fuel filler neck assembly in Figure 1 according to a first embodiment of the invention; Figure 3 is a schematic, cross-sectional, side view of a seal assembly forming a part of the fuel filler neck assembly in Figure 2; Figure 4 is a front view of a movable sealing element of the seal assembly in Figure 3; Figures 5a and 5b are a cross sectional rear view and a top view respectively of a guide element of the seal assembly in Figure 3; Figure 6 is a cross sectional front view of the seal assembly in Figure 3; Figure 7 is a representation of a retainer clip forming a part of the fuel filler neck assembly in Figure 2; Figure 8 is a front view of the fuel filler neck assembly of Figure 2, illustrating the relative positioning of the retainer clip and seal assembly; Figure 9 is a cross-sectional, side view of the fuel filler neck assembly in Figure 1 according to a second embodiment of the invention; Figures 10 to 12 are schematic, cross-sectional, side views of a seal assembly forming a part of the fuel filler neck assembly in Figure 9; Figures 13 and 14 are perspective views of the seal assembly in Figure 10; Figure 15 is a perspective cross section of the seal assembly in Figure 14; and Figures 16 and 17 are schematic, cross-sectional, side views of an alternative embodiment of the seal assembly to those shown in the previous Figures.

DETAILED DESCRIPTION

For the purpose of the following description it will be appreciated that references to upper, lower, upward, downward, above and below, for example, are not intended to be limiting and relate only to the orientation of the assembly as shown in the illustrations.

Referring to Figure 1, a vehicle 10 such as a PHEV vehicle, includes a fuel filler neck assembly 12 for a fuel tank (not shown) for storing fuel for powering the engine of the vehicle 10 during certain running periods. The fuel tank forms a part of a sealed internal combustion engine system (not shown) and the fuel filler neck assembly 12 incorporates a vapour release system to permit vapours that build up within the fuel tank when the engine is running to be released from the system in a controlled manner.

Figure 2 is a cross-sectional, side view of the fuel filler neck assembly 12 of the vehicle 10 in Figure 1. The fuel tank, to which the fuel filler neck provides fuel in use, is not shown, but is situated to the left hand side of the illustration in Figure 2.

The fuel filler neck assembly 12 includes an elongate tubular component 14 housed within a filler pipe 16. The tubular component 14 takes the form of a filler neck 18 into which a fuel dispensing nozzle 20 is inserted for delivering fuel to the tank. For the avoidance of doubt it will be appreciated that the nozzle 20 does not form part of the fuel filler neck assembly 12 but forms part of a separate and external fuel dispensing system (not shown). The nozzle 20 is inserted into the filler neck 18 via an inlet end of the filler neck 18 (the inlet end being to the right of the illustration) towards the fuel tank end of the filler neck 18 (to the left of the illustration). The nozzle 20 is inserted into the filler neck 18 in parallel with, or at a slight angle to, the filler pipe 16, and as such the filler neck assembly 12 can be considered to define a fuel dispensing direction 21, along which the nozzle 20 travels and dispenses fuel, in use.

A small rib or groove (not shown) may be incorporated into the tubular component 14 to retain an interlocking rib (not shown) of the nozzle 20 within the tank assembly 12 when fuelling of the vehicle 10 is in progress. The nozzle 20 can then be removed from the tank assembly 12 by lifting the nozzle 20 slightly before removal.

A radial outer cavity 22 is defined between the external surface of the filler neck 18 and the internal surface of the filler pipe 16, and is sealed by first and second radial seals 24 and 26. The first radial seal 24 is located further towards the inlet end of the filler neck 18 and the second radial seal 26 is located further towards the fuel tank end of the filler neck 18. A carbon canister (not shown) is connected to the radial outer cavity 22 by an opening 30 through the filler pipe 16 which is plugged with a ball valve 32.

The filler neck 18 defines an internal volume 34 which houses first and second vapour seal assemblies 36 and 38. The first and second vapour seals 36, 38 define a vapour cavity 40 therebetween. The vapour cavity 40 and radial outer cavity 22 are connected by an opening 42 through the filler neck 18 which is plugged with an umbrella valve 44.

The first vapour seal 36 extends radially inwards from the internal surface of the filler neck 18 and acts against the fuel nozzle 20, when inserted. The second vapour seal 38 is located radially inward of the second radial seal 26 and engages an internal end of the fuel nozzle 20. The second vapour seal 38 is configured to open communication between the vapour cavity 40 and the fuel tank when contact is made with the fuel dispensing nozzle 20 when it is inserted fully into the filler neck 18, and sufficient force is applied by the nozzle 20 to displace the second vapour seal 38 in the direction of the fuel tank. The first vapour seal 36 is configured to enable a fuel dispensing nozzle 20 inserted into the filler neck 18 to pass into the vapour cavity 40, whilst creating a seal with the fuel dispensing nozzle 20 so that the vapour cavity 40 is sealed from the remainder of the internal volume 34 of the filler neck 18.

Therefore, the fuel nozzle 20 is configured to pass into the fuel filler neck assembly 12 via an inlet end, form a seal with the first vapour seal 36, and to open the seal of the second vapour seal 38 prior to refuelling. In doing so, the formation of one seal and breaking of another enables vapour release, if required, from the fuel tank to the vapour cavity 40. Therefore, where a sealed system existed prior to introduction of the nozzle 20 between the second vapour seal 38 and the fuel tank, a new sealed system is formed between the fuel tank and the vapour cavity 40/first vapour seal 36. Due to a build-up of vapour within the fuel tank during operation of the vehicle 10, the sealed system formed by insertion of the fuel nozzle 20 is typically pressurised.

Returning to Figure 2, the filler neck 18 defines a shoulder 46, and the first vapour seal 36 is held in place between the shoulder 46 and a retainer clip 48. The retainer clip 48 anchors against the filler neck 18 at radially opposed recesses 49, and will be discussed in greater detail later in relation to Figures 7 and 8 below.

The first vapour seal 36 is shown in Figures 3 and 6, with the component parts of the seal 36 shown in Figures 4 and 5. As can be seen in these Figures, the first vapour seal 36 includes a guide element 50 and a movable sealing element 52, in the form of a sealable washer, mounted within the guide element 50. The washer is sealable as it is configured to form a seal with an inserted nozzle 20, as will be described in more detail below.

Both the guide element 50 and the sealing element 52 are generally circular in outer profile. In side view, and as shown in Figure 3, the guide element 50 has a U-shaped cross section defined by front and rear disc elements 54 and 56 joined by a closed base region 58 which defines a channel 59 for receiving the sealing element 52. An open top region 60 between the front and rear elements 54 and 56 permits the sealing element 52 to be inserted into the guide element 50 on assembly of the parts and to be removed and replaced easily if required. The open top region 60 is sealed by the filler neck 18 when the seal 36 is mounted in the filler neck 18 so that removal of the sealing element 52 is prohibited in use.

In use, there is no direct attachment between the guide element 50 and the sealing element 52. Therefore, the sealing element 52 is able to move by sliding, in either or both of horizontal (lateral or side-to-side) and vertical (up-and-down) directions, relative to the guide element 50 to enable the position of the inserted fuel nozzle 20 to be adjusted, relative to the filler pipe 16, as will be described in further detail below. In other words, the sealing element 52 is physically unconnected to the guide element 50, such that only the position of the front and rear elements 54, 56 and closed base region 58 of the guide element 50, and the filler neck 18 in use, constrain the movement sealing element 52. Thus, the guide element 50 can be considered to constrain movement of the sealing element 52 in the fuel dispensing direction 21 by the position of its front and rear elements 54 and 56. As will be discussed below, the guide element 50 further constrains movement of the nozzle 20 in other directions that are different and generally perpendicular to the fuel dispensing direction 21.

The guide element 50 comprises a front guide opening 62, and a rear guide opening 63. The front and rear guide openings 62 and 63 are respective openings in the front and rear elements 54 and 56. Referring especially to Figure 5a, the front guide opening 62 is generally rectangular, and in this example appears as a bulged rectangle; the sidewalls 64 being vertical, with curved end (top and bottom) walls 65. In the present embodiment, the rear guide opening 63 is of substantially similar shape as the front guide opening 62. The guide element 50 further comprises a positioning guide (not shown) that ensures that the seal assembly 36 can only be installed within the tubular component 14 in the correct orientation.

The sealing element 52 of the first vapour seal 36 is shown in Figures 3, 4 and 6, and comprises means for sealing against a nozzle 20. In this embodiment, the sealing means is a flexible lip 80 having an inner face 82 that surrounds a central opening or aperture 68 of the sealing element 52 and defines an outer perimeter of the aperture 68. The aperture 68 is configured to receive a nozzle 20 and the lip 80 is configured to form a seal with the nozzle 20 when received through the aperture 68 in use. The lip 80 is manufactured from a material suitable for forming a seal with the nozzle 20 and which is hard-wearing and low-friction. For example, Teflon or other similar compounds may be used for the lip 80.

The sealing element 52 further comprises a body portion 84 that surrounds the lip 80 and aperture 68, the body portion 84 being connected to an outer face 86 of the lip 80 at an inner face 88. The body portion 84 and lip 80 are typically fixed together using an adhesive. The body portion 84, which here comprises an annular disc formed of a resilient, fuel-resistant material, such as a plastic compound, comprises a front face 90 and a rear face 92 to which are mounted respective sealing rings 72. The sealing rings 72 abut the facing surfaces of the respective one of the front or rear elements 54, 56 of the guide element 50. The sealing rings 72 are here shown as being radially offset from one another, although they may instead be radially aligned with each other.

Preferably, the sealing rings 72 are partly inset (embedded) into the front and rear faces 90, 92 of the body portion 84 of the sealing element 52 to strengthen their attachment to the sealing element 52. In this case, providing the sealing rings 72 with different diameters and thus at different radial offsets makes it possible to avoid thinning the sealing element 52 at the same position on both sides (which would weaken the sealing element 52). More generally, it will be appreciated that the sealing rings 72 may have any suitable diameter, provided that diameter is greater than their respective guide openings 62, 63 so as to maintain the seal between sealing element 52 and guide element 50 at all positions of the sealing element 52 within the guide element 50. The two sealing rings 72 need not necessarily be coaxial, but preferably do not overlap.

Referring now to Figures 2 to 6, when refuelling is necessary, the fuel dispensing nozzle 20 is inserted by a user into the filler neck 18 and towards the first vapour seal 36. The fuel dispensing nozzle 20 passes through the guide openings 62, 63 of the guide element 50 and the aperture 68 of the sealing element 52 of the first vapour seal 36 and into the vapour cavity 40, towards the second vapour seal 38. A seal is formed between the lip 80 of the sealing element 52 and the nozzle 20. When the fuel dispensing nozzle 20 makes contact with the second vapour seal 38 and sufficient force is applied through the nozzle 20 in the direction of the seal 38 by the user, the seal 38 is displaced and refuelling of the vehicle 10 is allowed. Moreover, fuel vapour release to the vapour cavity 40 from the fuel tank is enabled. As such, the vapour cavity 40 becomes pressurised by opening the second seal 38 by the nozzle 20.

Vapour release from the vapour cavity 40 into the radial outer cavity 22 through the opening 42 in the filler neck 18 is regulated by the umbrella valve 44, which is configured to unplug the opening 42 to release vapour when the pressure in the vapour cavity 40 exceeds a predetermined value. The umbrella valve 44 prohibits movement of fuel vapour from the radial outer cavity 22 to the vapour cavity 40. Vapour can be released to the carbon canister (not shown) from the radial outer cavity 22 through the opening 30 in the filler pipe 16 by the action of the ball valve 32. As a safety feature, the ball valve 32 operates to stop liquid fuel from entering the carbon canister if fuel is dispensed from the nozzle 20 early, such that it fills the cavities 22 and 40. The carbon canister (not shown) retains the fuel vapour until it can be purged when the engine is started again, creating a less wasteful and cleaner system.

Other than via the umbrella valve 44 or through the open second vapour seal 38, fuel vapour cannot be released from the vapour cavity 40 when the fuel nozzle 20 is inserted. The inner face 82 of the lip 80 of the sealing element 52 forms a tight seal against the fuel nozzle 20, while each sealing ring 72 ensures that the vapour cannot pass through the seal 36 by an alternative route.

During refuelling, as described above, the fuel dispensing nozzle 20 is inserted into the filler neck 18 towards the first vapour seal 36. A number of features of the first vapour seal 36, which will now be discussed, aid in positioning the fuel dispensing nozzle 20 correctly.

Initially, the guide element 50 aids in positioning the fuel dispensing nozzle 20. As the guide element 50 is made of a mechanically hard material, such as steel or a fuel-resistant plastic compound, the front element 54 protects the sealing element 52 from being struck and damaged by the fuel dispensing nozzle 20. The resistance to forward movement of the fuel nozzle 20 when it touches the front element 54 of the guide element 50 should alert the user that the fuel dispensing nozzle 20 is misaligned.

Secondly, the front guide opening 62 horizontally (laterally) aligns the nozzle 20 with the sealing element 52 aperture 68 and the second vapour seal 38. Beneficially, the width of the front guide opening 62 acts as a go/no go gauge for the fuel dispensing nozzle 20, preventing mis-fuelling with the wrong type of fuel. Similarly, the aperture 68 is dimensioned to provide a secondary go/no go gauge. It will be appreciated that the guide openings 62 and 63 act to constrain the movement of the nozzle 20 when the seal has been formed, When the fuel nozzle 20 has been aligned with the front guide opening 62, the rounded, inner, sealing face 82 of the lip 80 of the sealing element 52 provides a self-centring function for the fuel dispensing nozzle 20.The placement of the fuel nozzle 20 does not have to be exact, as its movement will be corrected to the centre of the aperture 68 by the rounded face 82 to form a seal with the face 82 as it passes through.

The positioning of the fuel nozzle 20 with respect to the second vapour seal 38 does not need to be completely accurate, as when the fuel nozzle 20 is inserted through the sealing element 52, the sealing element 52 can be raised or lowered in order to vertically align the end of the fuel nozzle 20 with the second seal 38. The fuel nozzle 20 can therefore be inserted to refuel at a range of angles and refuelling can still occur.

If the first vapour seal 36 did not incorporate a movable sealing element 52, the user would have to remove and reinsert the fuel nozzle 20 if their initial attempt did not engage the second vapour seal 38 fully.

A further benefit associated with the sealing element 52 is that while being vertically adjustable, the sealing element 52 can also be rotated within the guide element 50, ensuring that when engaged with the second vapour seal 38, the fuel dispensing nozzle 20 can still be moved without disengaging or stressing the first vapour seal 36.

A degree of movement of the sealing element 52 provides more flexibility and greater convenience to the user when refuelling the vehicle 10.

Allowing the fuel dispensing nozzle 20 to move when engaged with the second vapour seal 38 allows a user to rest the nozzle 20 while automatic refuelling occurs, and also accounts for the user's arm tiring whilst refuelling. The front guide opening 62 additionally aids in this advantage of the invention, permitting a so-called 'drop down' function by facilitating vertical movement of the nozzle 20 in use without potentially damaging the seal. The vertical movement of the nozzle 20 is constrained by the base region 58 of the guide element 50 restricting the movement of the sealing element 52 within the channel 59, or by the underside of the nozzle 20 coming to rest on an upper surface of the lower part of the guide element 50.

After refuelling, the guide element 50, and particularly the restriction provided by the width of the front guide opening 62, prevents the sealing element 52 from being accidentally removed when the fuel dispensing nozzle 20 is removed.

In other embodiments of the invention, alternative front guide opening shapes and sizes are incorporated depending on the intended use and properties of the seal assembly. For example, an elliptic front guide opening provides more variety in the angle with which a fuel dispensing nozzle can pass through the sealing element aperture. However, an elliptic opening that exposes more of the sealing element may reduce the go/no-go functionality and lose the advantage of preventing mis-fuelling with the wrong type of fuel.

In the embodiment shown in the Figures, the shapes of the front and rear guide openings 62 and 63 are substantially similar. In other embodiments, however, the shape and size of the rear guide opening differs from the shape and size of the front guide opening. It is possible to incorporate many rear guide opening shapes and sizes, provided that the sealing element can be retained by the rear element of the guide element, and a seal is retained between the sealing rings of the sealing element and the internal faces of the guide element elements.

A representation of a retainer clip 48 for use in retaining a first vapour seal 36 is shown in Figure 7, and its positioning within the fuel filler neck assembly 12 relative to the first vapour seal 36 is shown in Figure 8. The retainer clip 48 is a compressible element for insertion into a filler neck 18. Having been compressed, the clip 48 is expandable to its original form to retain a seal 38 within a fuel filler neck assembly 12. As shown in Figure 7, the retainer clip 48 is formed of compressible and expandable means such as a sprung rod or pole shaped to adopt a shape that, when slightly compressed by squeezing inwardly at either end 53, 55 of the clip 48, will enable insertion into a filler neck 18. The retainer clip 48 incorporates opposed extension portions 51 configured to be received in recesses 49 within the filler neck 18 or to provide a retaining, outward force on the internal surface of the filler neck 18 to permit retention of the seal 36. The retainer clip 48 is typically manufactured from a relatively stiff, resiliently deformable material. The resilient properties of the retainer clip 48 ensure that compression of the clip 48 will not plastically deform it. Thus, squeezing of the clip 48 at its ends 53, 55 to permit insertion into the fuel filler neck assembly 12 will be followed by expansion of the clip 48 once released. It will be appreciated that it is the overall shape of the clip 48 which is compressible, rather than the material of which the clip 48 is formed. The material itself, at the thickness used to form the clip 48, is resiliently deformable and has an overall unstrained diameter which is larger than or substantially matches the interior diameter of the recesses 49 within the filler neck. When fitted into the filler neck 18, the clip 48 has a generally circular or part circular shape. However, portions of the clip 48 deviate inwardly from the circular shape, away from the wall of the filler neck 18, in order to trap the seal 36 against the shoulder 46. It will be appreciated that those parts of the clip 48 following the circular periphery engage with the wall of the filler neck 18, while those parts of the clip 48 which deviate from the circular periphery engage with the seal 36.

Figure 9 illustrates an alternative embodiment of a first vapour seal 136 within a fuel filler neck assembly 112. It will be appreciated that the fuel filler neck assembly 112 of Figure 9 shares the same or similar components as the fuel filler neck assembly 12 of Figure 2, with the exception of the first vapour seal 136, which will now be described.

The first vapour seal 136 of the embodiment is shown in greater detail in Figures 10 to 15. The seal 136 comprises a guide element 150 and a sealing element 152 fixed to a rear face 151 of the guide element 150. In an alternative embodiment, the sealing element 152 may be fixed to a front face of the guide element 150, or to both front and rear faces. Both the guide element 150 and the sealing element 152 are generally circular in outer profile as can be seen from Figure 14. As the sealing element 152 is directly attached, i.e. fixed, to the guide element 150, by means of an adhesive or other suitable attachment means, the sealing element 152 is unable to slide relative to the guide element 150 as in the embodiment shown in Figures 2 to 6. However, the sealing element 152 is configured to permit movement of a nozzle 120 relative to the guide element 150 when received within the sealing element 152, by (resilient) deformation or other means. Thus, the sealing element 152 is considered to be both fixed by direct attachment to the guide element 150, and movable relative to the guide element 150.

The guide element 150 comprises a front element 154 defining a guide opening 162. The front element 154 is connected to an annular rim 156 at the proximal edge 158 of the rim 156. The outer surface 160 of the rim 156 abuts the filler neck 118 when the vapour seal 136 is mounted within the assembly 112, and a distal edge 159 of the rim 156 abuts the shoulder 146 of the filler neck 118 to space the front element 154 from the shoulder 146. Referring especially to Figure 13, the guide opening 162 is generally rectangular, and in this example appears as a bulged rectangle; the sidewalls being vertical, with curved end walls. The guide element 150 further comprises a positioning guide 163, shown in Figure 14, that ensures that the seal assembly 152 is always installed within the tubular component 114 in the correct orientation. Here, it is shown that the rim 156 and front element 154 are integrally formed, although the guide element 150 may be formed of two or more separate parts.

The sealing element 152 is connected directly to the front element 154 of the guide element 150 at its rear face 151 and is aligned with the guide opening 162 such that it is mounted partially within the guide opening 162. The rear face 151 of the front element 154 faces inwardly towards the vapour cavity 140 when the first vapour seal 136 is mounted within the fuel filler neck assembly 112.

The sealing element 152, in the form of a circular grommet or fixed washer, comprises a front face 164, a rear face 166, and a central aperture or opening 168. The perimeter of the central aperture 168 is defined by a slanted internal face 182 which tapers away from the guide element 150 and guide opening 162. The aperture 168 in the sealing element 152 provides a self-centring function to guide the fuel dispensing nozzle 120 through the aperture 168 correctly.

Furthermore, the sealing element 152 is formed of an elastic material to permit deformation of the tapered internal face 182 of the sealing element 152 when the nozzle 120 passes through the sealing element 152, so as to form a seal therebetween.

The movement of the face 182 against the nozzle 120 ensures that the seal is formed fully between the sealing element 152 and the nozzle 120 before the nozzle 120 opens the second vapour seal 138. As shown in Figure 11, the tapered face 182 of the sealing element 152 forms a tight seal against the fuel nozzle 120. Vapour cannot pass through the first vapour seal 136 any other way due to the sealing element 152 being attached to the guide element 150.

Furthermore, the sealing element 152 permits the so-called 'drop down' function of a nozzle 120 to be used. Having inserted the nozzle 120 into the first vapour seal 136, in the manner shown in Figure 11, and then having engaged the second seal 138 to permit refuelling, the user may lower and release the fuel nozzle 120, which is able to drop downwardly. In the embodiment described in relation to Figures 2 to 6, the drop down function of the nozzle 20 was enabled by the sealing element 52 being unconnected to the guide element 50 and having the ability to slide relative to the guide element 50. Here, the nozzle 120 is permitted to drop down within the guide opening 162 by the elastic properties of the sealing element 152. Figure 12 represents a situation in which the nozzle 120 has been dropped down by the user. It can be seen that the seal with the nozzle 120 is maintained by the sealing element 152, but that the aperture 168 through the sealing element 152 has been biased downwardly, and that a greater amount of deformation has occurred in the lower part of the sealing element 152.

When the nozzle 120 is initially inserted into the aperture 168, and prior to the nozzle being dropped down, the aperture 168 and guide opening 162 are misaligned (not coaxial). That is, that the central axis of the aperture 168 is not the same as the central axis of the guide opening 162. As can be seen in Figure 15, the central axis of the aperture 168, here labelled 'A', is misaligned with the central axis of the guide opening 162, labelled B. The aperture 168 has a central axis A that, in the arrangement of Figure 15 where the movement of the aperture relative to the guide is in the vertical direction, is parallel with the central axis B of the guide opening 162 but vertically offset from it. The sealing element 152 is configured to maintain this position relative to the guide element 150 so as to facilitate receipt of the nozzle 120. The offsetting of the guide opening 162 ensures a maximum amount of drop down, while restricting movement in the opposite direction.

Furthermore, it should be noted that the guide opening 162 is also misaligned with the central axis of the guide element 150. In Figure 15, the central axis A of the aperture 168 is aligned with the central axis of the guide element 150, and so it can be seen that the central axis B of the guide opening 162 is also misaligned (not coaxial) with the guide element 150. This offsetting of the guide element 150 and opening 162 permits optimum placement of the aperture 168, and again also facilitates the drop-down function further.

An alternative embodiment of a first vapour seal 236 is shown in Figures 16 and 17, in which the sealing element 252 comprises a body portion 240 and a lip portion 242. In this embodiment, the lip portion 242 is made of the flexible material, whereas the body portion 240 is made of a material that is more robust. For example, the body portion 240 material may be a plastic or other lightweight material, providing said material is fuel-resistant.

This embodiment, which is a hybrid of the two embodiments described above, incorporates a tapered, flexible lip 280 to provide greater self-centring of a nozzle and slightly more flexibility.

Further embodiments are envisaged. For example, the lip and body portion of the sealing element of the embodiment of Figures 2 to 6 may be integrally formed of a flexible material, such as rubber, permitting high flexibility of the sealing element, and to permit the use of the drop down function of both of the above embodiments. Additionally, the lip and body portion of the sealing element of the embodiment of Figures 16 and 17 may also be integrally formed of a suitable flexible material.

Further embodiments of a first vapour seal are envisaged wherein the sealing element is bonded to the guide element. In these embodiments, the sealing element is flexibly manufactured to permit movement of an inserted nozzle. For example, this movement may be incorporated using a plurality of folds in the sealing element which create a concertina fold effect.

Claims

CLAIMS1. A seal assembly for use in a fuel tank assembly of a plug-in hybrid electric vehicle, the seal assembly comprising: a sealing element defining a seal opening for receiving a nozzle of a fuel dispensing system, in use, so as to define a seal therebetween; and a guide element to which the sealing element is fixed; wherein the sealing element is movable relative to the guide element to permit a degree of movement of the nozzle when the nozzle is dropped down, within the sealing element, without breaking the seal therebetween; and wherein the guide element serves to limit movement of the nozzle in at least one direction.
2. The seal assembly of Claim 1, wherein the nozzle is received through the sealing element in a first direction, and wherein the sealing element is movable relative to the guide element in at least a second, different direction.
3. The seal assembly of Claim 2, wherein the guide element serves to limit movement of the nozzle in each of the second direction and a third direction, the third direction being perpendicular to the second direction.
4. The seal assembly of Claim 3, wherein the guide element defines a guide opening for receiving the nozzle of the fuel dispensing system and for limiting movement of the nozzle within the sealing element, in use.
5. The seal assembly of Claim 4, wherein the guide opening limits movement of the nozzle within the sealing element in the third direction to a greater extent than in the second direction to enable the nozzle to be dropped down.
6. The seal assembly of Claim 4 or Claim 5, wherein the guide opening is generally rectangular.
7. The seal assembly of any of Claims 4 to 6, wherein the guide opening includes first and second opposed sidewalls which cooperate with the nozzle, in use, to limit movement of the nozzle in one direction.
8. The seal assembly of any of Claims 4 to 7, wherein the guide opening includes first and second opposed curved end walls which cooperate with the nozzle, in use, to limit movement of the nozzle in one direction.
9. The seal assembly of any of Claims 4 to 8, wherein the guide opening is shaped to receive only a nozzle for a specific type of fuel.
The seal assembly of any of Claims 4 to 9, wherein the guide opening has a central axis and the seal opening has a central axis, and wherein the central axes are misaligned by a degree of misalignment prior to receiving the nozzle, in use.
11. The seal assembly of Claim 10, wherein the degree of misalignment is adjustable when the nozzle is received within the seal opening.
12. The seal assembly of any preceding claim, wherein the sealing element is configured to deform to permit movement of the nozzle relative to the guide element, in use.
13. The seal assembly of any preceding claim, wherein the seal opening comprises a slanted internal face for receiving the nozzle.
14. The seal assembly of any preceding claim, wherein the guide element is manufactured from a material that is mechanically harder than that of the sealing 25 element.
15. The seal assembly of any preceding claim, wherein the sealing element comprises a circular grommet.
16. The seal assembly of any preceding claim, the seal assembly consisting of the guide element and sealing element only.
17. A retainer clip configured to fix the seal assembly of any preceding claim within a fuel filler neck assembly of a vehicle.
18. A fuel filler neck assembly for a vehicle, the fuel filler neck assembly comprising the seal assembly of any of Claims 1 to 16.
19. The fuel filler neck assembly of Claim 18, wherein the seal assembly is fixed in place against a shoulder of the fuel filler neck assembly by the retainer clip of Claim 17.
20. The fuel filler neck assembly of Claim 18 or Claim 19, further comprising a second seal for a fuel tank of the fuel tank assembly configured to provide access to the fuel tank when opened by the nozzle, the seal assembly and second seal being mounted in a fuel filler neck of the fuel filler neck assembly and defining a vapour cavity therebetween from which vapour may be released via a vapour release valve in the fuel filler neck, and wherein, in use, when a seal is formed between the nozzle and the seal assembly, and when the second seal is open, the vapour cavity is pressurized and vapour is released from the fuel tank into the vapour cavity for release via the valve.
21. A vehicle comprising the fuel filler neck assembly as claimed in any of Claims 18 to 20.
22. The vehicle of Claim 21 comprising an upwardly facing surface, and wherein the fuel filler neck assembly is oriented on the vehicle such that, in use, the nozzle is inserted into the fuel filler neck assembly through the upwardly facing surface of the vehicle and wherein the seal assembly limits movement of the nozzle in at least two substantially horizontal directions.
23. The vehicle of Claim 21 comprising an sideward facing surface, and wherein the fuel filler neck assembly is oriented on the vehicle such that, in use, the nozzle is inserted into the fuel filler neck assembly through the sideward facing surface of the vehicle and wherein the seal assembly limits movement of the nozzle in at least one substantially horizontal direction and at least one substantially vertical direction.