MULTI LAYERED SEALING STRUCTURE FOR PLASTIC FUEL
FILLER HOUSING
FIELD OF INVENTION:
[001) The present subject matter described herein, relates to a fuel filler
5 assembly or fuel box housing or fuel filler housing for a vehicle 'l.nd, in partic.1.1lar,
to a sealing structure between fuel inlet pipe and fuel filler housing mounted in
inner surface of body panel of the vehicle. More particularly, present subject
matter pertains to multilayer sealing structure around periphery of the fuel inlet
pipe and prevents leakage of fuel fumes in cabin area of the vehicle.
10 BACKGROUND AND PRIOR ART AND PROBLEM IN PRIOR ART:
[002] In known fuel system of the vehicles or automobiles or cars, fuel filler
housing is mounted inside body panel, preferably left and right side of the vehicle.
In the fuel filler housing, an inlet fuel pipe extends from fuel tank to surface of the
side body panel of the vehicle. Through the inlet fuel pipe, fuel can be refueled at
15 any time. The fuel filler housing covers upper surface of the fuel inlet pipe and
provide an opening and closing means. Upper portion of the fuel inlet pipe is
accessible from the fuel filler housing.
[003) The fuel filler housing can be made of sheet metal or plastic materials.
This invention pertains to the plastic fuel filler assemblies. The fuel filler housings
20 are injection molded housing and are generally made of two different types of
materials, one hard material and other being soft material. Generally, the hard
material is used to mold the housing and the soft materials are used to m~ke seals
of the housing. The person skilled in the art knows how to make the fuel filler
housings using inject molding.
25 [004) Fig. 1 illustrates structure of the fuel filler housing, in particularly, plastic
fuel filler housing. The fuel filler housing has a cover which includes fuel lid 1
and hinge arm 2. The hinge arm 2 connects the fuel lid 1 to fuel filler housing
(interchangeably can be called as fuel box) 4 with the help of pivot pin 3. The fuel
box 4 has an opening at bottom to receive the fuel inlet pipe. Position of the fuel
2
liq 1 is such that it is opened and closed during refueling of the vehicle. In the
existing fuel filler housing two sealing are required, i.e., one at outer surface of
the side body panel and second at the periphery of the fuel inlet pipe.
[005] In the existing designs of the second sealing, i.e., at the periphery. of the
5 fuel inlet pipe, soft material, such as rubber, generally, ethylene propylene diene
· monomer rubber (EPDM) or thermoplastic olefin (TPO/TPE) is press fitted
around the fuel inlet pipe neck and outer surface of the inner body panel of the
vehicle. The sealing is co-molded/ 2 shot molded/over-molded with the housing
hard material~ such as PP: filled with glass fiber. Primary tasks of the sealing is to
1 0 hold/allow the entry of the fuel inlet pipe in the fuel filler housing and seal the gap
between the fuel filler housing and the fuel inlet pipe; and prevents the entry of
fumes/vapors of fuel released in the fuel filler housing area inside the cabin area
of the vehicle. If soft seals are not properly ·established, it is highly possible that
the fuel vapors will leak and enter into the cabin area of the vehicle. This will lead
15 · to the discomfort of the passenger(s) inside the cabin. The body panel has opening
in the cabin area of the vehicle.
[006] Conventionally, snap-ring seal includes two functional entities, an ove~molded
hard component snap-ring and an over-molded soft component sealing
part. The hard component of an over-molded design utilizes an integrated snap
20 feature that allows it to be attached into the inner sheet metal of a motor vehicle.
The soft component of the over-molded inner snap-ring creates a flexible sealing
surface. When it is urged against the inner sheet metal.
[007] In the known designs of the second sealing 5(around fuel inlet pipe/inner
panel), it is difficult to block the entry of fuel vapors in the cabin area. The sealing
25 is supposed to prevent the entry of fuel fumes/water vapors etc. in the cabin area.
However, as the sealing part is only press fitted against fuel inlet pipe with no
positive mounting/multiple blockages to fumes entry/leakage inside cabin, to keep
the same in its position, therefore there are chanc~s of part shape getting deformed
and/or moved from its condition of interference upon being exposed to vibrations
30 during varied vehicle running conditions and exposure to dirt, water, gasoline,
IPO OtLHL 25-&1-2&18 17~42
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other reagents etc. Eventually, this may i~ad to creation of gap between the fuel
inlet pipe & rubber sealing. The created gap provides a free passage to .the fuel
fumes/water vapor to get diffused inside the cabin area of the vehicle. The
presence of the fuel fumes in the cabin area may lead to discomfort of passenger. -
5 Therefore, it is necessary to provide some additional provision for preventing the
easy entry of fumes inside cabin.
OBJECTS OF THE INVENTION:
[008] The principal objective of the present invention is to block free passage of
fuel fumes or water vapors from the fuel filler. housing to cabin area of the
10 vehicle.
[009] Another object of the present invention is to provide a sealing structure
between the periphery of the fuel inlet pipe and fuel filler housing to block the
passage of fuel fumes dr•water vapors into the cabin area of the vehicle.
[0010] Another object of the present invention is to reduce the requirement of the
15 additional part/material to make the sealing structure for blocking of the free
passage of the fuel fumes or water vapors.
[0011] Yet another object of the present invention is to allow easy assembly of.
the sealing structure and assembly of the sealing structure does not lead to paint
chip-off in the inner body panel of the vehicle. As the sealing material is EPDM
20 or TPE, they are softer material & while fitment, there is no rubbing marks/scratch
generated on painted panel. No paint peel off is there.
[0012] Yet another object of the present invention is to ensure sealing even after
the drain hole to completely block the passage of the fuel fumes or water vapors.
[0013] Yet another object of the present invention, the present sealing strm.:ture is
25 feasible from the production point of view.
SUMMARY OF THE INVENTION:
[0014] The present subject matter relates a multilayered sealing structure for the
fuel filler housing to block entry of fuel fumes or water vapors from the fuel filler
IPO DELHL 25-&l-2816 17~42
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housing to cabin area of vehicle. The sealing structure includes a circular fuel inlet
and a multilayer sealing structure. The multilayered sealing structure is disposed
around periphery of outer surface of the circular fuel inlet pipe. The multilayer
. sealing structure is disposed between the circular fuel inlet pipe and inner surface
5 of body paud of the vehicle. 'l'he multilayer sealing structure blocks movement of
the fuel fumes or water vapors from the gap betwet:u lhe circular fuel inlet pipe
and the inner surface of the body panel of the vehicle. The multilayer sealing
structure further comprises four layers of the seal at different locations to block
the movement ofthe fumes completely.
1 0 [0015] In order to further understand the characteristics and technical contents of
the present subject matter, a description relating thereto will be made with
reference to the accompanying drawings. However, the drawings are illustrative
only but not used to limit scope of the present subject matter.
BRIEF DESCRIPTION OF.THE DRAWINGS
15 [0016] It is to be noted, however, that the appended drawings illustrate only
typical embodiments of the present subject matter and ·are therefore not to be
considered for limiting of its scope, for the invention may admit to other equally
effective embodiments. The detailed description is described with reference to the
accompanying figures. In the figures, a reference number identifies the figure in
20 which the reference number first appears. The same numbers are used throughout
the figures to reference like features and components. Some embodiments of
system or methods or structure in accordance with embodiments of the present
subject matter are now described, by way of example, and with reference to the
accompanying figures, in which:
25 [0017] Fig. 1 illustrates perspective view of the fuel filler housing known in the
art;
[0018] Fig. 2 illustrates a cross sectional view of primary sealing structure (single
layer) in the fuel filler housing known in the art;
IPO D~LHI 25-81-2016 17
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[0019] Fig. 3 illustrates cross sectional v1ew of multilayer sealing structure
around the periphery of fuel inlet pipe, in accordance with an embodiment of the
present subject matter;
[0020] Fig. 4 illustrates the exploded perspective view of the multilayer sealing
5 structure around the periphery of the fuel inlet pipe, in accordance with an
embodiment of the present subject matter; and
[0021] Fig. 5 illustrates the exploded perspective view of the multilayer sealing
structure near drain hole, in accordance with an embodiment of the present subject
matter.
10 [0022] The figures depict embodiments of the present subject matter for the
purposes of illustration only. A person skilled in the art will easily recognize from
the following description that alternative embodiments of the structures and
methods illustrated herein may be employed without departing from the principles
of the disclosure described herein.
15 DESCRIPTION OF THE PREFERRED EMBODIMENTS:
[0023] The subject matter disclosed herein relates. to multilayer sealing structure
around the periphery of the circular fuel inlet pipe present in the fuel filler
housing. The multilayer sealing structure seals the gap between outer surface of
the circular fuel inlet pipe in the fuel filler housing and inner surface of the body
20 panel of the vehicle. The present multilayer sealing structure provides a positive
sealing or strong sealing between the fuel filler housing and the inner surface of
the body panel of the vehicle to block the free passage of the fuel fumes or water
vapors from the fuel filler housing to cabin area of the vehicle.
[0024] As explained above in the problem in prior art section, the vehicle can be
25 refueled from the fuel filler housing which is made of plastic material. There are
chances of fuel fumes formation during vehicle running/parked condition during
to temp/pressure variation inside fuel tank. A provision has been provided in the
fuel cap fitted on the furl inlet opening to allow a small portion of these fumes to
be released. When released, these fumes are inside fuel filler housing and there are
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chances that the same may get diffused inside vehicle cabin, if not sealed
properly.
[0025] Conventional sealing is only press fitted against fuel inlet pipe with no
positive mounting/multiple blockages to fumes entry/leakage inside cabin. There
5 are chances of part shape getting deformed and/or moved from its condition of
interference upon being exposed to vibrations during varied vehicle running
conditions and exposure to dirt,. water, gasoline, other reagents etc. Eventually,
this may lead to creation of gap between the fuel inlet pipe & rubber sealing. The
. created gap provides a free passage to the fuel fumes/water vapors to get diffused
10 inside the cabin area of the vehicle. The presence of the fuel fumes in the cabin
area may lead to discomfort of passenger.
[0026] According to an implementation of the present subject matter, a
multilayer sealing structure is provided around the periphery of the fuel inlet pipe
is described. The fuel inlet pipe is circular in shape. The present sealing structure
15 seals the gap between outer surface of the circular fuel inlet pipe in the fuel filler
housing and inner surface of the body panel of the vehicle. The present sealing
structure is in contact with the inner surface of the body panel of the vehicle and
plastic material of the fuel filler housing. The present sealing structure provides a
positive sealing or strong sealing between fuel filler housing and the inner surface
20 - of the body panel of the vehicle to block the free passage of the fuel fumes or
water vapors from the fuel filler housing to cabin area of the vehicle.
[0027] In one embodiment of the present subje.ct matter, the multilayer sealing
structure is disposed between the outer surface of the circular inlet pipe and the
inner surface of the body panel of the vehicle. The multilayered sealing structure
25 seals the gap be:tween the outer surface of the circular fuel inlet pipe and the inner
surface of the body panel of the vehicle which is connected with cabin area of the
vehicle.
[0028] In another embodiment of the present subject matter, the multilayer sealing
structure has plurality of sealing, such as primary sealing, secondary sealing,
30 tertiary sealing, and fourth sealing. The primary sealing exists between the fuel
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inlet pipe and inner surface of body panel of the vehicle. The primary sealing is a
single line contact with the outer surface of the fuel inlet pipe and is generally iri
interference design which is press fitted dming assembly. The present
embodiment refers to multilayer sealing struc~ure where all primary, secondary,
5 tertiary, de., sealing is made of single continuous rubber material, for example,
Ethylene Propylene Diene Monomer rubber (EPDM) and ThermoPlastic olefin
(TPO/TPE). Therefore, it is easy to make the multilayer sealing from a single
continuous material. The secondary sealing is in continuation of the primary
sealing. Further the secondary sealing is a point contact with the inner surface of
1 0 the body panel of the vehicle.
[0029] The tertiary sealing is also a continuation of the primary sealing which
comes after secondary sealing. The tertiary sealing is in contact with the inner
surface of the body panel of the vehicle. Further, the tertiary sealing is a lip
shaped sealing structure with required interference with the inner surface of the
15 body panel of the vehicle. Through the multilayer sealing structure, movement of
fuel fumes/water vapors into the cabin can be stopped completely.
[0030] It should be noted that the description and figures merely illustrate the
principles of the present subject matter. It should be appreciated by those skilled
in the art that conception and specific embodiment disclosed may be readily
20 utilized as a basis for modifying or designing other structures for carrying out the
i
same purposes of the present subject matter. It should also be appreciated by those
skilled in the art that by devising various arrangements that, although not
explicitly described or shown herein, embody the principles of the present subject
matter and are included within its spirit and scope. Furthermore, all examples
25 . recited herein are principally intended expressly to be for pedagogical purposes to
aid the reader in understanding the principles of the present subject matter and the
concepts contributed by the inventor(s) to furthering the art, and are to be
construed as being without limitation to such specifically recited examples and
conditions. The novel features which. are believed to be characteristic of the
30 present subject matter, both as to its organization and method of operation,
.. IP 0 DEL H .JL ·2 5.-81-2018 17 : lf2
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together with further objects and advantages will be better understood from the
following description when considered in connection with the accompanying
figures.
[0031) These and other advantages of the present subject mattt:r would be
5 described in greater detail with reference to the following figures. It shoulrl be
noted thut the:: description merely illustrates the principles of the present subject
matter. It will thus be appreciated that those skilled in the art will be able to devise
various arrangements that, although not explicitly described herein, embody the
principles of the present subject matter and are included within its scope.
10 [0032] Fig. 3 illustrates cross sectional perspective view of the multilayer sealing
structure 8 disposed between the fuel filler housing 4 and the inner surface of the
body panel of the vehicle, in accordance with an embodiment of the present
subject matter. In the said embodiment, a multilayer sealing structure 8 (or 1 0) is
disposed between outer circular surface of the fuel inlet pipe 6 and .the inner
15 surface of the body panel 7 of the vehicle. The lower part or rear part of the body
panel which is near to the rear wheel having drain hole 9 along with fourth ~ealing
15 (as shown in the figure 6) to block the movement of fumes/vapors.
[0033] Fig. 4 illustrates the structure of multilayer sealing 8 in greater detail. The
primary sealing 11 is disposed between the outer surface of the circular fuel inlet
20 . pipe 6 and the inner surface of the body panel 7 of the vehicle. The body panel of
the vehicle is sheet metal panel made of metal steel. The primary sealing 11 seals
a gap between the circular fuel inlet pipe 6 and the inner surface of the body panel
7 of the vehicle. Further, the fuel filler housing 4 is mounted inside the body panel
7 of the vehicle. The multilayer sealing structure is connected with the inner
25 surface of the body panel 7 of the vehicle at lower base and vertically with the
fuel filler housing 4.
[0034] The primary sealing 11 seals the gap and stops the movement of the
fumes/vapors from entry in the cabin area of the vehicle from the gap. The
secondary sealing 12 which is in continuation of the primary sealing 11. The
30 secondary sealing 12 is in point contact with the inner surface of the body panel 7
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IP 0 .. U 1:: L l-U .!. - ..1!.
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of the vehicle. The multilayer sealing structure 8 is over molded with the fuel
filler housing 4. These over-molding techniques and process are well known to the
person skilled in the art and therefore it will not be described in detail here to
avoid confusion and ambiguity in the present subject matter. The gap between the
5 inner panel is filled with the fuel filler housing. By design, it has been ensured
that the concerned sealing is in cnnt::~,c:-.t with inner. panel surface, even after
considering manufacturing tolerances. However, further to ascertain the same, a
positive mounting concept may or may not be used which can hold the sealing
against the inner panel. The same can be tightened with tightening feature like
10 bolts/screws/clip etc. This positive mounting can be achieved with an additional
part or integrated part.
[0035) The tertiary sealing 13 further provide a sealing with the inner surface of
the body panel 7 of the vehicle and the fuel filler housing 4. The tertiary sealing
13 is a lip shaped sealing which act as a positive sealing to avoid any gap between
15 the inner surface of the body panel 7 and the fuel filler housing 4. The tertiary
sealing 13 may or may not be pushed against the inner surface of the body panel 7
of the vehicle with the help of some 'additional part or integrated part 14. In case
to ensure strong lip sealing of the tertiary sealing 13 with the inner surface of the
body panel 7, an additional part may be fixed to the inner surface of the body
20 panel 7 by bolt mounting. As explained above, the multilayer sealing structure 8
establish a physical attachment with the inner surface of the body panei 7 of the
vehicle.
[0036] Fig. 5 illustrates the structure of fourth sealing 15 near the drain hole 9 of
the fuel filler housing 4 in greater detail. A separate sealing, i.e., fourth sealing 15
25 is provided after the drain hole 9 in the fuel filler housing 4. The drain hole 9 is
located near the rear wheel area and it is in downward direction. The fourth
sealing 15 is also made of rubber material, for example, ethylene propylene diene
monomer rubber (EPDM) and thermoplastic olefin (TPO/TPE). The fourth sealing
15 is provided after the drain hole 9 in reverse V shape where opening faces of V
30 face downward direction. In the fourth sealing 15, one side of the V shape sealing
IPO DELHI 25~Di-20l6 17~42
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is connected with the hard plastic material of the fuel filler housing 4 and another
side is against with the metal sheet of the inner surface of the body panel 7 of the
vehicle. The fourth sealing I5 stops the movement of fumes which escapes from
the drain hole 9 and blocks them entering into the connected cabin area.
5 [0037] In reference to the present subject matter, when the primary sealing II gets
deformed due to vehicle running conditions and road conditions, exposure to dirt,
water, gasoline and other reagents, there are high chances of distortion of the
primary sealing II. The primary sealing II gets deformed and a small gap is
. formed between the fuel inlet pipe 6 and primary sealing II. The fuel fumes or
I 0 water vapors escape the primary sealing II from the gap and reaches to the
secondary sealing 12. The secondary sealing 12 stops further movement of the
fumes/vapors.
[0038] In some cases where secondary sealing 12 also fails to block the fuel
fumes/water vapors from entry in the cabin area due to breakage or deformation of
15 the secondary sealing, the third sealing I J or tertiary sealing I3 blocks the free
passage of the fuel fumes/water vapors into the cabin area: The tertiary sealing I3
is a strong sealing or positive sealing which blocks the movement of fumes/vapor
completely.
[0039] Further, when minor fumes/vapors which pass through the drain hole 9,
20 the fourth sealing 15. is provided after the drain hole 9 which blocks the entry of
fuel fumes/ water vapors into the cabin area. Therefore, from the present sealing
structure we can prevent the entry of the fuel fumes or water vapors in the 'cabin
area of the vehicle completely.
[0040) Although embodiments for the present subject matter have been described
25 in language specific to structural features, it is to be understood that the present
subject matter is not necessarily limited to the specific features described. Rather,
the specific features and methods are disclosed as embodiments for the present
subject . matter. Numerous· modifications and adaptations of the
system/device/structure of the present invention will be apparent to those skilled
30 in the art, and thus it is intended by the appended claims to cover all such
II
modifications and adaptatiop.s which fall within the scope of the present subject
matter.

We claim:
1. A sealing structure for a fuel filler housing ( 4) of a vehicle, the seal
structure comprises:
a circular fuel inlet pipe (6) for receiving fuel; and
a multilayered sealing structure (8) which is disposed around
periphery of outer surface of the circular fuel inlet pipe (6).
2. The sealing structure as claimed in claim 1,. wherein the multilayered
sealing structure (8) is disposed between the outer surface of the circular fuel inlet
pipe (6) and an inner surface of body panel (7) of the vehicle, wherein the
10 multilayered sealing structure (8) seals gap between the outer surface of the
circular fuel inlet pipe (6) and the inner surface of the body panel (7) of the
·vehicle.
3. The sealing structure as claimed in claim 2, wherein the inner surface of
15 the body panel (7) is connected with cabin area of the vehicle .
.I 4. The sealing structure as claimed. in claim 1, wherein the multilayered
sealing structure (8) comprises a plurality of sealing, wherein the plurality of
sealing comprises:
20 a primary sealing (11) disposed between the outer surface of the
circular fuel inlet pipe (6) and the inner surface of body panel (7) of the
vehiCle;
a secondary sealing (12) is continuation of the primary sealing (11)
which is in contact with the inner surface of the body panel (7) of the
25 vehicle; and
30. 5.
a tertiary sealing (13) is continuation of the secondary sealing (12)
which is in contact with the inner sl.rrface of the body panel (7) of the
vehicle.
The sealing structure as claimed in claim 4, wherein the fourth sealing (13)
is a lip shaped sealing structure.
IPO DELHI 25-Bl-2Dl& 17!42
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6. The· sealing structure as claimed in claim 4, wherein the contact of the
secondary sealing is a point contact.
7. . The sealing structure as claimed in claim 4, wherein the tertiary sealing
5 (13) ·is ensured by pushing the lerliary sealing (13) against surface of the inner
surface of the body panel (7) with help of integrated part (14) which is fixed on
the inner surface of the body panel (7).
8. The sealing structure as claimed in claim 4, wherein the tertiary sealing
10 (13) is ensured by pushing the tertiary sealing (13) against surface of the inner
· panel with help of additional part (14) bolted to the inner panel.
9. The sealing structure as claimed in claim 1, wherein the sealing structure is
made of rubber material specifically Ethylene Propylene Diene Monomer · (M-
15 class) rubber (EPDM) and Thermo-Plastic Olefin (TPO/TPE
20
10. The sealing structure as claimed in claim 4, wherein the end parts of the
tertiary sealing (13) is connected with fuel box housing (4) and the inner surface
of the body panel (7) of vehicle.
11. The sealing structure as claimed in claim 4, wherein the plurality of
sealing further comprises a fourth sealing (15) present after drain hole (9) at rear
wheel area of the fuel box housing (4) to block fumes.
25 12. The sealing structure as Claimed in claim 4, wherein the tertiary sealing
(13) remains in contact with the inner surface of the body panel (7) ofthe vehicle
all time.
13. The sealing structure as claimed in claim 1, wherein the fuel box hqusing
30 (4) is made of plastic material.
14. The sealing structure as claimed in claim 1, wherein. the fuel box housing
(4) has an opening to be opened and closed by a lid body (1) mounted on the fuel
box housing ( 4 ).
5 15. The sealing structure as claimed in claim 1, wherein the multilayered
sealing structure (8) is provided by simple process of injection molding.