FUEL TANK FOR A MOTORCYCLE

Field of Invention

The present invention relates to a "Fuel tank for a motorcycle", more specifically relates to an inlet structure of the fuel tank for a scooter type motorcycle.

Background of the invention

Motorcycles, powered by engines normally require gasoline fuels. The fuel for running the engine is stored in the fuel tank at sufficient levels for operation of the vehicle. The fuel tank stores sufficient quantity of fuel for facilitating fuel flow to the carburettor of the internal combustion engine for continuous running of the vehicle. The fuel storage tanks are made up of metal or from suitable polymers in most of the motorcycles. In the known type of motorcycles the fuel tanks are fabricated from metal and mounted between the seat and the handle bar assembly. These fuel tanks add aesthetic appeal to the vehicles. Such exposed fuel tanks are provided with a lockable cap to avoid fuel pilferage. In some vehicles, especially in scooter type vehicles, in order to efficiently exploit the available space, the fuel tank shape and size are made suitable to the vehicle layout requirements. In many scooter-type vehicles, the fuel tank Is provided directly below the seat. In such type of vehicles, since the utility box is also located below the seat, a lock is provided to open the seat which is hinged in the front to access the utility box and the fuel tank. Such fuel tanks are normally made of polymers, such as plastic and threads are formed at the inlet portion of the fuel tank so as to accommodate a screwed type fuel tank cap. In such type of vehicles, every time the rider has to open the seat for fuel refilling and which can be done only when the rider steps out the vehicle which is not the case when fuel tanks are exposed outside. In order to avoid this problem, especially in scooter type vehicles, the fuel tank is provided in the floor board of the vehicle. The fuel inlet, is provided suitably either at the front side or at the rear side of the vehicle to facilitate fuel filling. Hoses are used to connect the fuel tank body and the fuel inlet assembly to facilitate the fuel filling process.

However this arrangement requires a long flexible hose connection with screw type hose clips to connect the inlet and fuel tank body. Further the fuel tank needs to have high ground clearance to safeguard the fuel tank from getting damaged. In addition to this there exists a chance for leakage of fuel and reduction in durability of the hose connected to the fuel tank.

Hence the objective of the invention is to provide a fuel tank for a scooter type vehicle having a lockable cap exposed outside to facilitate easy filling without the need for any hose connection and having higher ground clearance.

Object of the invention

The main object of the present invention is to provide an improved mounting structure for the fuel tank In a scooter type motorcycle, having a lockable cap and exposed outside in order to facilitate easy fuel refilling.

Another objective of the present invention is to provide a fuel tank mounted on the rear side of the scooter type vehicle to provide for easy refuelling without opening the seat.

It is further an object of the present invention to provide a fuel tank mounting structure for a scooter, capable of increasing freedom of designing a fuel tank and of facilitating mounting a fuel tank on the body of the scooter.

Yet another object of the present invention is to provide a fuel tank for a scooter type motorcycle which is of simple construction and capable of reducing the leakage of fuel through the fuel inlet part of the fuel tank.

It is further an object of the present invention to provide a fuel tank for a scooter type motorcycle without the requirement of a hose to connect the fuel tank body and the fuel inlet assembly.

It is also an object of the present invention to provide for a fuel tank having higher ground clearance compared to conventional scooter type motorcycles.

Summary

The subject matter herein described is directed to a fuel tank system for scooter type motorcycle, which is simple in construction and capable of reducing the leakage of the fuel through the fuel inlet part of the fuel tank. The present invention includes a fuel tank system mounted at a position below the vehicle rear side frame panel and behind the rider's seat.

The fuel tank system of the present invention includes a fuel tank body and a fuel inlet assembly. The fuel tank body has an extended neck portion to which the fuel inlet assembly is integrally formed and which is protruded outside the side frame panels. The fuel inlet assembly is provided on top portion of the fuel tank body in such a way so as to be exposed behind the seat. The fuel inlet assembly is made up of two parts namely an injection moulded deep drawn metallic insert and a ring made of polymer. The metallic insert is enmoulded with polymeric sharp labyrinth grooves at the bottom side, such that the labyrinth grooves of polymer formed on the outer periphery of the metallic insert facilitates an integral joint between the metallic insert and the inlet assembly of fuel tank. A polymer ring is placed at bottom portion of the fuel inlet assembly, such that ring makes contact between the bottom portion of the metallic insert and the top neck portion of the fuel tank body.

These and other features, aspects, and advantages of the present subject matter will be better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to be used to identify key features or essential of the claimed subject matter, nor it is intended to be used to limit the scope of the claimed subject matter.

Brief description of the accompanying drawings

The above and other features, aspects, and advantages of the subject matter will become better understood with regard to the following description, appended claims, and accompanying drawings where:

Fig.1 illustrates a scooter type motorcycle of the present invention;

Fig. 2 is the left side view of the fuel tank system with the resin ring and the metallic insert;

Fig. 3A is a front side view showing the metallic insert for the fuel tank provided with holes;

Fig. 3B is a sectional view illustrating the metallic inlet after injection enmoulding with resin;

Fig. 4A is a sectional view showing the injection enmoulded inlet and resin ring assembly;

Fig. 4B illustrates the sectional view of the resin ring;

Fig.5 illustrates the partial view showing the section of metallic inlet & resin fuel tank integration.

Detailed description of the preferred embodiments

The subject matter will be described with reference to the accompanying drawings.

The scooter type motorcycle, as illustrated in Fig 1, can be divided into three major portions, the front portion F, the middle portion W and the rear/tail portion R, The front portion F comprises of the head tube (16), the handle bar, the front suspension and the front wheel (14) with necessary brakes (1), to which a front fork (2) is connected to hold the front wheel. A front fender (3) is provided to cover the front wheel (14). The front panel (4) attached to the front portion of the frame structure protects the scooter type motorcycle from damages.

The middle portion l\1 comprises of the step through portion (5), which is used to carry objects by the rider. A rider's seat (6) is provided in middle portion VI of the motorcycle. The motorcycle has a stand (7) to balance the motorcycle at stand still position. An engine assembly (8) is accommodated under the front portion of rider's seat (6) for fuel combustion.

The rear/tail portion R comprises of a fuel tank assembly (100) under the rear portion of rider's seat (6) to store enough quantity of fuel. The swing arm (11) is connected from rear wheel (15) to the middle portion U in order to bind the rear wheel (15) to middle portion M of the scooter type motorcycle. A rear shock absorber (12) is mounted between the shaft of rear wheel and rider's seat (6) to increase the comfort of the rider's seat (6). The rear fender (13) is attached to the rear/tail portion R of the motorcycle so as to protect the rear wheel from mud and water splashes.

In assembling such a vehicle, especially the body covers, there are many sub assemblies and these are independently mounted onto the frame at different locations. The body covers are mounted to the frame using brackets.

Scooter-type vehicles, or scooters, include a frame assembly, which usually supports the body of a scooter, along with front (14) and rear wheels (15). A frame for a scooter-type vehicle comprises of at least one front wheel (14), at least one rear wheel (15) and a vehicle body.

The frame assembly of a scooter-type vehicle is an elongated structure, which typically extends from a forward end to a rearward end of the scooter. A handlebar assembly and a seat (6) are supported at opposing ends of the frame assembly and a generally open area is defined there between. Accordingly, the open area between the handlebar assembly and the seat assembly (6) allows the scooter to be easily straddled, or mounted, as opposed to a typical motorcycle, wherein a motorcycle fuel tank occupies the space between the handlebar assembly and the seat assembly (6). Such an arrangement may be referred to as a "step-through" frame assembly. Generally, a scooter frame assembly is constructed of a welded-up assembly of individual tubular members.

The frame assembly includes a head tube (16), which supports a front wheel (14) suspension assembly of the vehicle. A main tube (17) extends from the head tube (16) to a rearward end of the vehicle body. A swing arm (11) is pivotally supported by the main tube (17) and supports a rear wheel (15) of the vehicle. The frame assembly may include a pair of rear tubes (18) removeably coupled to the main tube (17) and defining a space there between.

The rear tubes (18) preferably supports at least one component of the scooter-type vehicle in the space, such as a fuel tank system (100), for example.

Typically, front and rear suspension assemblies are operatively positioned between the front (14) and rear wheels (15) and the frame assembly. The front suspension assembly commonly is a telescopic fork arrangement, while the rear suspension assembly is a swing type arrangement. In a scooter, the rear suspension swing arm (11) typically supports a power unit, which is configured to drive the rear wheel (15) of the scooter.

One aspect of the present invention, involves a scooter type motorcycle having at least one front wheel (14), at least one rear wheel (15), a vehicle body and a frame assembly. The frame includes a head tube (16), a main tube (17) extending downwards from the head tube (16) to the bottom of the floor board. At this particular location a bridge is provided to which the reanward end of the main tube (17) is coupled to the forward end portion of two rear tubes (18), which extends to a rearward portion of the vehicle body. The two tubes which run parallel to each other extend in the upward direction from the floorboard and are bent at an appropriate location such that it runs parallel to the floor board.

The middle portion of the said scooter type motorcycle comprises of the engine assembly (8), which is swingably mounted on the frame. One end of the engine assembly (8) is connected to the toggle link and the other end is attached to the rear wheel. The rear suspensions (12), which may either be provided on one or both sides of the vehicle body, are coupled to the rear tube (18) on one end and to the rear section of the engine (8) on the other.

The aesthetics of the rear portion of the vehicle is improved by means of the side cover frame assembly, which comprises of the side cover left and the side cover right.

A rear fender (13) that protects the rider and the engine (8) from mud and water splash is mounted on the rear tubes (19) by means of brackets and screws.

The rear tubes (18) are in turn joined at the rearmost portion by means of formed sheet metal brackets, which also act as pillion handle mounting brackets. The tail lamp along with the rear turn signal lamps are supported on the pillion handle mounting bracket.

The space between the utility box and the pillion handle mounting bracket supports the fuel tank system (100).

The present invention was conceived in view of the above problems of the prior art, and it is accordingly an object of the present invention to provide a fuel tank system (100) in rear portion (R) of a scooter-type vehicle, which makes it possible to easily perform refuelling without opening the seat.

It is accordingly the objective of the present invention to provide a fuel tank system (100) for motor scooters to be a simple construction and capable of reducing the leakage of the fuel through the fuel inlet part of the fuel tank (100). The present invention includes a fuel tank system (100) top mounted at a position below the vehicle rear side frame panel and behind the rear seat.

As shown in Fig. 2, the fuel tank system (100) comprises of a fuel tank body (101) and a fuel inlet assembly (102). The fuel tank body (101) has an extended neck shaped portion which acts as a connecting member (103), on which the fuel inlet assembly (102) is integrally formed and which Is protruded outside the rear side frame panels.

The fuel tank system (100) is located behind the rider's seat (6) on the rear tubes (18), in such a way that the fuel tank system (100) is held between the rear frames. The fuel inlet assembly (102) is provided on the top of the fuel tank body (101) in such a way so as to be exposed behind the seat (6).

As shown in Fig 3A, the fuel inlet assembly (102) is made up of two parts namely, an injection enmoulded with a deep drawn metallic insert (201) and a ring (204) made of polymer as illustrated in Fig. 4B.

As illustrated in Fig. 3B, the metallic insert (201) which is injection enmoulded is provided with adequate and sharp labyrinth grooves (202) formed at the outer periphery at its bottom most portion. Also the metallic insert (201) as can be seen in (Fig. 3A) includes a plurality of holes (203) with perforations at the bottom portion of the insert (201) for allowing the plastic material from the connecting neck portion (103) of the fuel tank body (101) to flow and fill all the holes (203), thereby facilitating an integral injection moulded joint between the metallic insert (201) and the inlet portion of the fuel tank.

The metallic insert (201) is enmoulded with sharp labyrinth grooves (202) at the bottom side, such that the labyrinth grooves (202) formed on the outer periphery of the metallic insert (201) allows for providing an integral joint between the metallic insert (201) and the inlet assembly (102) of fuel tank, which allows preventing the rotation of the fuel inlet assembly (102) integrated to plastic fuel tank body (101) and also increases the torque bearing capacity. Also the moulding of the metallic insert (201) with labyrinth grooves (202) and the fuel tank inlet assembly (102) allows to cover the surface defects of the metallic inlet (201) and to increase the dimensional stability.

The polymer ring (204), as shown in Fig. 4A is placed at bottom portion of the fuel inlet assembly (102), such that ring (204) contacts the bottom portion of the metallic insert (201) and the top neck (103) portion of the fuel tank body (101).

The ring (204) in the inlet assembly (102) acts as a stopper to avoid plastic material flow towards fuel tank cap locking zone at the fuel tank inlet in order to facilitate better and easy locking of fuel tank cap during the moulding process between the labyrinth grooves (202) of metallic insert (201) and fuel tank inlet assembly (102), and thereby providing a leak proof joint between the plastic fuel tank body (101) and fuel tank inlet assembly (102).

Fig.5 illustrates the partial view showing the section of metallic inlet and resin fuel tank integration.

Although the subject matter has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternate embodiments of the subject matter, will become apparent to persons skilled in the art upon reference to the description of the subject matter. It is therefore contemplated that such modifications can be made without departing from the spirit or scope of the present subject matter as defined.

We claim:

1) A fuel tank system (100) for storing fuel in a vehicle, said fuel tank system (100) comprising:

a fuel tank body (101) connected to the frame of the vehicle for storing fuel;

a fuel inlet assembly (102) integrally fixed to the fuel tank body (101) wherein the said fuel inlet assembly (102) comprises of:

an insert (201) enmoulded to the top of the fuel inlet assembly (102);

a ring (204) placed at the bottom portion of the fuel inlet assembly (102).

2) The fuel tank system (100) as claimed in claim 1, wherein the said insert (201) is made of metal enmoulded along with suitable resin having labyrinth grooves (202) provided at the outer periphery at the bottom most portion.

3) The fuel tank system (100) as claimed in claim 1, wherein the said insert (201) is injection enmoulded to enable integral fitment to the fuel tank inlet assembly (102).

4) The fuel tank system (100) as claimed in claim 1, wherein the said ring (204) is made of resin.

5) The fuel tank system (100) as claimed in claim 1, wherein the said ring (204) connects the bottom portion of the insert (201) to the top of the connecting portion (103) of the fuel tank body (101).

6) The fuel tank system (100) as herein substantially described and illustrated with reference to the accompanying drawings.