FUEL TANK ASSEMBLY FOR TWO WHEELERS

FIELD OF THE INVENTION

The present invention relates to a fuel tank assembly for a scooter type vehicle and more particularly to a fuel pump mounting unit disposed in the fuel tank of the scooter type vehicle.

BACKGROUND

There is known a conventional scooter type vehicle in which a part of the seat is disposed above the fuel tank comprising a vertically erect fuel pump unit, which is used to supply fuel to the carburettor. Further, the fuel tank top includes a recess through which the fuel pump unit is inserted into the fuel tank. During vehicle running condition, the fuel pump unit rotates for pumping the fuel, causing vibrations and thereby leading to transfer of load to the fuel tank top. Also, in these types of scooters, the pillion load is carried by the seat, which is disposed on the load receiving section of the fuel tank i.e. upper surface of fuel tank top, near the fuel pump mounting section, thereby leading to yielding of the fuel tank top. Thus, the fuel tank top acts as a load carrying member in the scooters having above described vehicle configuration. Therefore, it is desirable to configure a fuel tank top of substantial thickness, having enough stiffness to carry pillion load and the load due to vibrations caused by the fuel pump, so as to prevent yielding of the fuel tank top. However, increasing the thickness of the entire fuel tank top not only leads to increase in the weight of the fuel tank but also leads to increase in manufacturing costs.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide an improved fuel tank assembly for a scooter type vehicle, which improves the stiffness of the fuel tank top locally, in an area which is subject to load conditions. It is another object of the invention to provide an improved fuel tank assembly which ensures stiffness of the fuel tank top, without increasing the thickness of the fuel tank top. The present subject matter described herein relates to an improved fuel tank assembly, wherein the fuel tank assembly aids in increasing the stiffness of the fuel tank top locally. Pursuant to the present invention, a stiffness member is provided in the lower surface of a fuel tank top, in order to increase the stiffness of the fuel tank top locally. According to the present invention, the fuel tank assembly includes a fuel tank top and a fuel tank bottom, wherein, the fuel tank top comprising an upper surface and a lower surface, includes a fuel pump unit and a fuel gauge disposed on the upper surface. Further, a recess provided on the upper surface of the fuel tank top receives the mounting of the fuel pump unit. According to the present invention, the stiffness member is welded to the lower surface of the fuel tank top and below the recess provided for the mounting of the fuel pump unit.

The stiffness member, thus disposed, aids in increasing the stiffness of the fuel tank top, as it is disposed in an area of the fuel tank top, which receives significant load from a seat disposed above the fuel tank top and also due to the vibrations caused by the fuel pump unit. Moreover, since the stiffness member is directly welded to the lower surface of the fuel tank top, the time involved in assembly of the fuel tank is also less, thereby increasing productivity. Also, the number of parts used for increasing the stiffness of the fuel tank top is reduced, thereby decreasing manufacturing costs. The foregoing objective and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 illustrates a typical scooter type vehicle with a fuel tank assembly in accordance to the present invention.

Figure 2 illustrates an exploded view of the fuel pump unit disposed in the fuel tank in accordance to the present invention.

Figure 3 illustrates an enlarged cross sectional view of the fuel pump unit as mounted to the upper surface of the fuel tank top in accordance to the present invention.

Figure 4 illustrates a top view of lower surface of the fuel tank top in accordance to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Exemplary embodiments of a fuel tank assembly of a scooter type vehicle, in accordance to the present invention will be described hereunder with reference to the accompanying drawings. Various features of the fuel tank assembly in accordance to the present invention will become discernible from the following description set out hereunder. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. It is to be noted that terms "upper", "lower", "right", "left", "front", "rear", "downward", "upward", "top", "bottom" and like terms are used herein based on the illustrated state or in a standing state of the vehicle with a driver riding thereon. Furthermore, a longitudinal axis refers to a front to rear axis relative to the vehicle, while a lateral axis refers to a side to side, or left to right axis relative to the vehicle. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

Referring to Figure 1, the layout of a typical scooter type vehicle, identified generally by the reference numeral 1 is elaborated. In the present embodiment, the scooter type vehicle 1 comprises a body frame 10 having a swinging engine 30 connected thereto for vertical swinging movement, a front wheel 2, and a rear wheel 3 supported to the rear of the swinging engine 30. The body frame 10 includes a head pipe 11 at the front end of the vehicle; from the head pipe 11 extends obliquely downwardly a main tube 12; and from the main tube 12 extend a pair of left and right backstays 13 obliquely upwardly and a pair of seat rails 14 further extend approximately horizontally from the left and right backstays 13 towards a rear end of the vehicle. On the head pipe 11 disposed at a forward end of the vehicle, a handle bar 15 is supported. Further, a rear view mirror 17 is supported on the handle bar 15.

A front fork 23 is pivotally supported by the head pipe 11 such that the front fork 23 is steerable to the left and right. The front wheel 2 is journaled to the lower end of the front fork 23. A front fender 16 is arranged on the front fork 23 to cover an upper portion of the front wheel 2. A seat 20 is disposed above the seat rails 14. The layout of the seat 20 is such that two riders can be seated on a front portion and a rear portion. A fuel tank 40 is disposed below the seat, such that a centre portion of the seat 20 is disposed over the fuel tank 40. A pillion handle 25 is mounted in the underside of the seat 20. An embodiment of the fuel tank assembly 40 in accordance to the present invention is exemplified with reference to Figure 2. In the present embodiment, the fuel tank assembly 40 comprises of a fuel tank top 40a and a fuel tank bottom 40b. Further, the fuel tank top 40a comprises a plurality of peripheral plate collars 55 along its peripheral edges, wherein the peripheral plate collars 55 are provided with apertures 55a to receive fasteners used to mount the fuel tank top 40a to the fuel tank bottom 40b.

A recess 43 is formed in the upper surface 40aa of the fuel tank top 40a to receive a mounting of a fuel pump unit 44. A circular bottom flange 45, having an opening to receive a head 44a of the fuel pump unit 44 is welded to the upper surface 40aa of the fuel tank top 40a and above the recess 43. The fuel pump unit 44 is inserted into the recess 43 through the opening provided in the circular bottom flange 45. Further, a top flange 46 is fastened to the bottom flange 45, thus firmly securing the fuel pump unit 44 to the upper surface 40aa of the fuel tank top 40a in a vertically erect position. A stiffener member 60 is welded to the lower surface 40ab of the fuel tank top 40a and is disposed below the recess 43 formed in the upper surface 40aa of the fuel tank top 40a. In the present embodiment the stiffener member 60 is circular in shape. The disposition of the stiffener member 60 below the recess 43 provided for the mounting of fuel pump unit 44, aids in increasing the stiffness of the fuel tank top 40a locally.

Besides the fuel pump unit 44, a fuel gauge 65 is also mounted in the upper surface 40aa of the fuel tank top 40a. The fuel tank top 40a is also provided with a cap 56 for closing the fuel inlet. Figure 3 illustrates a cross sectional view of the fuel tank assembly 40. An enlarged view of the fuel pump unit mounting along with the stiffener member 60 is shown alongside. As may be seen in the figure, the stiffener member 60 is disposed locally below the recess 43 provided in the upper surface 40aa of the fuel tank top 40a, in a manner such that an inner circumference of the stiffener member 60 adjoins an outer circumference of the recess 43. In the present embodiment the recess 43 is formed in such a manner that a rim 43a of the recess 43 extends inwards towards the lower surface 40ab of the fuel tank top 40a. Further, a circular bottom

— - flange 45 is located and welded above the recess 43, in order to receive the mounting of the fuel pump unit 44. The bottom flange 45 is located in a manner such that its outer circumference engages with the inner circumference of the rim 43a. Further, the fuel pump unit 44 is inserted into an opening provided in the circular bottom flange 45. Thereafter, a top flange 46 secures the fuel pump unit 44 with the bottom flange 45 by means of plurality of fasteners. Thus, in the present embodiment the fuel pump unit 44 is tightly secured to the upper surface 40aa of the fuel tank top 40a in a vertically erect position by the circular bottom flange 45 and the top flange 46 from the top side and by the stiffener member 60 from the bottom side. Thereby, shaking of the fuel pump unit 44 due to vibrations is minimised and therefore transfer of load to the fuel tank top 40a is also reduced.

Besides securing the fuel pump unit 44 from the bottom side, the stiffener member 60 provides stiffness to the fuel tank top 40a from the bottom side. In the present embodiment the stiffener member 60 is composed of sheet metal and has a thickness in the range of 1 millimetre to 2 millimetres. Since the area of the fuel tank top in which the fuel pump mounting unit 40 is disposed is subject to maximum load conditions and therefore more prone to yielding, by disposing the stiffener member 60 in the same area, it is enabling the achievement of increased local stiffness without having to increase the thickness of the entire fuel tank top 40a. Figure 4 illustrates a top view of lower surface 40ab of the fuel tank top 40a. As shown in the figure, the stiffener member 60 is forged to the lower surface 40ab of the fuel tank top 40a by welding. In one embodiment the circular stiffener member 60 is spot welded to the lower surface 40ab of the fuel tank top 40a. In another embodiment the stiffener member 60 is projection welded to the lower surface 40ab of the fuel tank top 40a.

The stiffener member 60 is thus disposed in the lower surface 40ab of the fuel tank top 40a, in a manner such that it's inner circumference 60a adjoins a base of the rim 43a of the recess 43. Since the stiffness member 60 is directly welded to the lower surface 40ab of the fuel tank top 40a, the time involved in assembly of the fuel tank is less, thereby increasing the productivity. Further, since no fasteners are used to locate the stiffener member, the number of parts used to increase the stiffness of the fuel tank top is less. Thus, the stiffener member 60 as described in the above embodiments aids in increasing the stiffness of the fuel tank top 40a locally, in the area where a fuel pump unit 44 is disposed, thus improving the load bearing capacity of the fuel tank top 40a. While the present invention has been shown and described with reference to the foregoing preferred embodiments, it will be apparent to those skilled in the art that changes in form, connection, and detail may be made therein without departing from the spirit and scope of the invention as defined in the appended claims:

WE CLAIM:

1. A fuel tank assembly (40) for a scooter type vehicle (1), said fuel tank assembly (40) comprising: a fuel tank top (40a) and a fuel tank bottom (40b), wherein the fuel tank top (40a) comprising an upper surface (40aa) and a lower surface (40ab), further includes a recess (43) formed in the upper surface (40aa) to receive a fuel pump unit (44); characterized in that a stiffener member (60) is disposed in the lower surface (40ab) of the fuel tank top (40a) and below the recess (43).

2. The fuel tank assembly (40), as claimed in claim 1, wherein the stiffener member (60) is circular in shape.

3. The fuel tank assembly (40), as claimed in claim 1, wherein the stiffener member (60) has a thickness in the range of 1 millimetre to 2 millimetres.

4. The fuel tank assembly (40), as claimed in claim 1, wherein the stiffener member (60) is composed of a sheet metal material

5. The fuel tank assembly (40), as claimed in claim 1, wherein the stiffener member (60) is secured to the lower surface (40ab) of the fuel tank top (40a) by a forging process.

6. A scooter type vehicle (1) comprising the fuel tank assembly (40) as claimed in claims 1-5.