FIELD OF INVENTION
This invention relates to a sealing structure for plastic fuel filler assembly of vehicle.
BACKGROUND/PRIOR ART
Fuel filler assembly is commonly known to be available with vehicle, which comprises a housing adopted to connect to the vehicle and having a fuel pipe opening. It further comprises a hinge arm attached to the housing which is capable of closing and opening the fuel filler assembly. Thus the fuel filler assembly is having a housing with an opening at its base wherein the housing is covered by means of lid, attached to the hinge arm.
It can be made of sheet metal /plastic. In case of sheet metal fuel filler, sheet metal base of the housing is welded to the wheel housing surface therebehind with the provision of sealant between two welded surfaces. The sealing ensures no leakage of fumes/ water vapors etc. from the concerned area. However it adds to weight of the vehicle. Hence, for reducing weight plastic fuel filler was suggested in the art which is mounted on body panel.
Now reference may be made to fig. 1. Said plastic fuel filler assembly consists of a plastic housing Box Comp which has an injection molded housing/fuel box (1) comprising of over-molding of two different materials (usually one hard & one soft). There is a plastic injection molded hinge arm (2) fitted to said housing with the help of pivot pin(3) (plastic or metallic) and a spring inside and an injection, molded plastic fuel lid (4)fitted onto the hinge arm. The hinge arm can be integrated alongwith the plastic lid part. Alternatively the same can be fitted by various means. The rubber base of housing has an opening (5) to accommodate a fuel'filler neck for filling fuel into the fuel tank therethrough. The hinge arm is capable of closing 8s opening the fuel filler assembly when the fuel tank is required to be filled.

The rubber sealing is press fitted against the fuel filler neck thereby providing scaling between the opening in rubber base and filler neck so as to seal against the leakage. Said rubber sealing is co-molded/ 2K molded/ over-molded with the housing hard material. The sealing 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 filler neck with no positive mounting in the nearby area to keep the same in its position, therefore there 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 filler neck & rubber sealing. In this regard reference may be made to fig 2 indicating the folio wing:-
Fuel lid-1'
Hinge Arm - 2'
Fuel Box-3'
Wheel housing surface - 4'
Rubber base of housing - 5'
Pipe comp fuel filler - 6'
This gap leads to leakage from around the housing into the rear portion of cabin in flow communication therewith. This leads to diffusion of vapors especially fuel fumes in the cabin area which causes discomfort to the passenger inside the cabin. Therefore the gap is required to be effectively sealed so as to address the aforesaid issues.

The present invention focuses on the provision of sealing in the plastic fuel box area with the surrounding. So that it enables improved sealing (leak proof) of the fuel box area with its surrounding thereby preventing leakage of fuel fumes/water vapor etc. in the cabin area which if gets diffused inside the vehicle may cause discomfort to the passenger.
Some prior patent/publications may be discussed hereinbelow:
US2014084550 (Al) : Tt is directed to a sealing otructurc of a fuel inlet bux without deforming a mounting surface of a vehicle side body. The fuel inlet box comprises a main body member and a sealing member. The main body member has a box portion, and a storage wall bulging from a side wall of the box portion with a space of storing an arm portion of a lid body. The mounting surface is placed between a base portion of the storage wall and a flange portion, and faces the flange portion through a gap extending in a planar direction. A seal lip of the sealing member is secured on the flange portion, extending toward the mounting surface and inclined toward an outer peripheral side of an opening.
According to another disclosure, a fuel filler assembly for a vehicle comprising:
a housing attached to a hinge arm for closing and opening the fuel filler assembly, wherein a claw, plunger is attached to the housing for locking and unlocking the hinge arm with the housing. A seal is provided on the housing around the periphery of the claw plunger wherein the seal provides air tight budding with the hinge arm and the housing around the claw plunger when the hinge arm locks with the claw plunger.
According to another embodiment, a claw plunger is attached to the housing which has a locking head protruding through the housing; and a bellow, sealed between the locking head of the claw plunger and the housing surface wherein

the bellow is intact between the locking head of the claw plunger and the. housing.
None of the above can fulfill the requirements of the present invention for which it is designed.
OBJECTS OF THE INVENTION
An object of this invention is to propose a sealing structure for plastic fuel filler assembly of vehicle which effectively seals the housing area (fuel box area) from the cabin side of the vehicle.
Another object of this invention is to provide a sealing structure for plastic fuel filler assembly of vehicle which overcomes drawbacks of prior arts.
Further object of this invention is to propose a sealing structure for plastic fuel filler assembly of vehicle which prevents leakage of any fluid from the fuel box area into the cabin area of vehicle.
SUMMARY OF INVENTION
According to this invention there is provided a sealing structure for plastic fuel filler assembly of vehicle comprising a single piece forming substantially a ring structure, which is accommodated in the housing of said fuel filler assembly wherein outer profile of the ring structure corresponds to the inner profile of base of housing and inner profile of which is such that it maintains required clearance from the adjacent parts.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Further objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with the accompanying drawings of exemplary embodiments of invention and wherein:
Fig. 1 shows: Conventional plastic fuel filler assembly of vehicle.
Fig. 2 shows: Section of assembly of conventional plastic fuel filler assembly of vehicle on wheel housing surface.
Fig. 3A shows: One side surface of sealing structure of Present invention.
Fig. 3B shows: Another side surface of sealing structure according to present invention.
Fig. 4 shows: Mounting of sealing structure of invention onto base of housing of fuel filler assembly.
"Fig. 5 shows: Section of assembly of plastic fuel filler assembly with wheel housing surface in accordance with the present invention.
DETAIL DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE
ACCOMPANYING DRAWINGS
The instant invention teaches regarding a sealing structure for plastic fuel filler assembly, wherein the structure is placed inside the housing (fuel box) and secured to base thereof. For the same reference may be made to fig 3A and 3B. The sealing structure forms substantially a ring structure, outer profile of wliich corresponds to the inner profile of base of housing. Inner profile of the structure is such that it maintains required clearance from the adjacent parts

such as fuel ' filler neck during mounting. The thickness of said sealing structure is optimum so as to avoid war page in the course of manufacturing.
Atieast one side surface of the. sealing structure as in fig 3A may be provided with-multitude of ribs (1A). The ribs constitute strengthening ribs in order to strengthen the structure. There is provision of a plurality of through holes (2A) along the side, surface of the sealing structure maintaining a gap therebcLween for bolting the structure with the base of housing and wheel housing surface from inside said housing (fuel box) thereby applying pressure for effective sealing of the base against the back wheel housing surface.
As can be seen there is provision of uniform part section around bolt area (3A) to prevent rubber sealing from getting torn while bolted or thereafter as uniform pressure is applied on the sealing part at bolt/screw mounting.
In addition to the above, a protruded part (4A) is provided along the inner and outer circumference of one side surface of the sealing structure facing base of the housing during assembly. The assembly is carried out by means of a plurality of bolts (as shown in fig 4) to hold the structure in position which presses the rubber sealing base against the wheel housing surface. The protrusion (4A) is meant for establishing uniform contact between the base and structure.
The other side surface of the sealing structure as illustrated in fig 3B preferably bears smooth surface for aestheticness as it is exposed to user.
For mounting of the sealing structure of the invention in the housing of plastic fuel filler assembly, reference may be made to fig 5showing the following features:

Fuel lid - IB
Hinge Arm -.213
Box Housing - 3B
Ring structure - 4B
Wheel housing surface (inner panel) - 5B
Rubber sealing base - 6B
Fuel filler Neck - 7B
Bolt & Nut arrangement - 8B
The sealing structure of invention relies on the following design criteria:
© It should press the rubber sealing base against the wheel housing
surface for efficient sealing, e It should allow easy fitment with the help of bolts/screws etc. © Optimization of section to allow uniform distribution of pressure, so as to
ensure no tearing of rubber sealing post assembly and during vehicle life
span. e It should be less in weight.

Advantageous Features
- Effective sealing of the clearance between housing area (fuel box area) and cabin side of the vehicle
- No leakage of fuel fumes/vapours in the cabin side area.
- Facilitates fitting thereof.
- Efficient functioning.
-. Light in weight b}r maintaining optimum thickness.
It is to be noted that the present invention is susceptible to modifications, adaptations and changes by those skilled in the art. Such variant embodiments employing the concepts and features of this invention are intended to be within the scope of the present invention, which is further set forth under the following claims:-

WE CLAIM:
1. A sealing structure for plastic fuel filler assembly of vehicle comprising a single piece forming substantially a ring structure, which .is accommodated in the ho using of said fuel tiller assembly wherein outer profile of the ring structure corresponds to the inner profile of base of housing and inner profile of which is such that it maintains required clearance from the adjacent parts.
2. A sealing structure for plastic fuel filler assembly of vehicle as claimed in claim 1 wherein the side surface facing rubber sealing base of the housing during assembly is preferably having the ribs.
3. A sealing structure for plastic fuel filler assembly of vehicle as claimed in claim 1 or 2 wherein atleast one side surface of the ring structure is provided with a plurality of ribs constituting strengthening ribs so as to strengthen the structure.
4. A sealing structure for plastic fuel filler assembly of vehicle as claimed in any of the proceeding claims wherein the side surface directing towards the rubber sealing base comprising a protruded part along inner and outer circumference thereof.
5. A sealing structure for plastic fuel filler assembly of vehicle as claimed in any of the proceeding claims wherein the substantially ring structure is provided with multitude of through holes along side surface thereof maintaining a gap therebetween for accommodating bolt/screw there through during assembly of the structure with base and wheel housing surface.

6. A sealing structure for plastic fuel filler assembly of vehicle as claimed in any of the proceeding claims comprising of uniform part section around the bolt area to prevent rubber sealing base from getting torn owing to application of uniform pressure on the base at bolt/screw mounting.
7. A sealing structure for plastic fuel filler assembly of vehicle as claimed in any of the proceeding claims wherein the other side surface of the structure exposed to U3er is pieferably having smooth surface for aestheticness.
8. A sealing structure for plastic fuel filler assembly of vehicle as claimed in any of the proceeding claims is associated with the advantageous features such as herein described.
9. A sealing structure for plastic fuel filler assembly of vehicle substantially as herein described with reference to the accompanying drawings.