TECHNICAL FIELD
The present subject matter relates to a straddle type vehicle. More particularly, the present subject matter relates to the fuel tank assembly of the straddle type vehicles.
BACKGROUND
The straddle type vehicles are basically one of the most popular kind of the vehicle among the world's population. These kinds of vehicles are mostly powered by four stroke engines. Conventionally carburetor type system has been implemented in vehicles for supplying & metering fuel quantity to the engine. With need to enhance performance, power output & efficiency of same engine as well as reduce emissions, fuel injection system has become popular in step through type vehicles. Thus, a fuel management system is implemented in vehicles to control the fuel being supplied to the engine at right time & in right quantity.
Often with vehicles being commercialized for use in commutation and market purpose & variety of users, depending on the market needs, vehicle manufacturers often face a challenge of handling variety of fuel supply systems for same vehicle platform with variant of carburetor system or a fuel injection system. The fuel management system of the internal combustion engine has to use the combination of fuel tank along with the fuel pump module to deliver fuel in the engine with the help of the fuel injector. The vehicle fuel system is responsible for delivering the right amount of fuel from a fuel tank to the fuel injector, to maintain an appropriate amount of fuel in the engine for the process of internal combustion.
With ever increasing number of vehicles used for personal transport and its contribution to the pollution of environment in terms of the emission, the evaporative emissions also add to the pollution in terms of unburnt and burnt hydrocarbons. By very basic physical properties of the gasoline fuels primarily used for transportation, evaporative emissions are bound to exist under normal environment conditions and temperatures ranging from ambient temperatures to temperature encountered during various operating conditions. The gasoline fuel has propensity to vaporize at room temperatures within respective container and this emission needs to be purged to avoid undue pressure development in the container. Such emissions are often referred to as

evaporative emissions. There is a constant drive from manufacturers to bring down the extent of emissions in the automotive sector.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The detailed description is described with reference to the accompanying figures.
The same numbers are used throughout the drawings to reference like features and
components.
[0006] Fig.1 is an isometric view of a straddle type vehicle as per one embodiment of the
present invention.
[0007] Fig.2 is the side view of the straddle type vehicle with the fuel tank assembly as
per one embodiment of the present invention.
[0008] Fig. 3 is an assembled view of the fuel tank assembly with the wheel hugger and
rear fender as per one embodiment of the present invention
[0009] Fig. 3a is an assembled view of the fuel tank assembly with quadrants of the
wheel as per one embodiment of the present invention.
DETAILED DESCRIPTION
[00010] The conventional carburetor fuel systems lack in the several major aspects like as
lacks efficiency in terms of fuel consumption and performance of the engine. Also, majorly responsible for the emission of harmful gases which are the main cause for polluting the environment.
[00011] In order to address the shortcomings of the conventional carburetor system, an
Electronic Fuel Injection System or EFI has been developed as an improvement over the carburetor in order to calibrate and optimize the fuel/air ratio. The electronic fuel injection system or EFI is utilized to better control fuel to air ratios in order to provide better performance, improve emissions and drivability. Moreover, the need of precise fuel supply creates a necessity for introduction of Electronic Fuel Injection (EFI) system in existing carburetor vehicles.
[00012] Generally, the typical electronic fuel injection system comprises a fuel tank, a fuel
pump that is operatively coupled to the fuel tank that directs fuel into the engine. Further, as an improvement over the carburetor, the Electronic Fuel Injection system (EFI) utilizes

advanced electronic techniques to adjust the air fuel mixture to reduce the evaporative emission in the environment. Hence, as engines moved away from carburetors and towards fuel injection, the conversion of the carburetor to the Electronic Fuel Injection system (EFI) involves different types of electrical and mechanical modifications in the vehicle.
[00013] Typically, in the straddle type vehicle with a swinging powertrain e.g. a scooter
type saddle vehicle, the engine is mounted on a lower side of the storage box where the storage box is opened and closed by a seat pivotable in an up and down direction. Further, the fuel tank assembly is mounted at the rear side of the straddle type vehicle and also, the storage box is packaged in front of the fuel tank assembly. Further, the fuel tank assembly is covered by a surrounding component like storage box at the front, rear fender and wheel hugger at the bottom, side covers disposed at the side of the fuel tank assembly and tail lamp in the rear side of the fuel tank assembly.
[00014] Therefore, the conventional construction and disposition of surrounding
components in the straddle type vehicle restricts the increase in the volume of fuel tank assembly. As when the volume of the fuel tank assembly increases without changing the layouts and position of the surrounding components, it increases the challenge of interference with the surrounding components reducing the margin of operating static & dynamic clearances, potentially leading to an adverse effect on the durability of the fuel tank assembly & the vehicle as a whole.
[00015] Generally, in the fuel tank assembly of the straddle type vehicle, the fuel pump is
mounted on the top surface of the fuel tank assembly. The bottom portion of the fuel pump has typically similar operating clearance with respect to the bottom portion of the fuel tank assembly of the straddle type vehicle, which increases the volume of unused fuel in the fuel tank assembly thereby leading to high quantity of the dead fuel volume in the fuel tank assembly.
[00016] Further, in the known art, the fuel tank is disposed above the rear fender
extending on both lateral sides of the rear wheel and further, the fuel tank assembly is conforming with the profile of rear fender, potentially leading to the inadequate clearance

of dynamic interference with the surrounding components with usage including deterioration arising out of over prolonged usage.
[00017] Hence, there exists a challenge of designing an efficient fuel tank assembly,
which can be accommodated in a compact vehicle layout with adequate operating clearance without interfering with the surrounding components while ensuring increased volume of the fuel tank assembly without any major change in design and manufacturing set-up of the conventional vehicle.
[00018] Therefore, there is a need to have an improved & compact layout of the fuel tank
assembly of the straddle type vehicle which overcomes all of the above problems and other problems known in the art.
[00019] The present invention provides a solution to the above problems while meeting
the requirements of flexible platform design enabling ease of modification in vehicle from carburetor system to fuel injection system, while increasing the durability of the fuel tank assembly etc.
[00020] With the above objectives in view, the present invention relates to the
electronically controlled fuel injection system and more particularly to the improved design & compact layout of the fuel tank assembly, which ensures the increased usable volume and less dead volume in the fuel tank assembly.
[00021] As per one aspect of the present invention, the frame of the straddle type vehicle
comprises of the main tube, down tube etc., where the engine is mounted to the frame through the engine mounting bracket, ensure the swingable mounting of the engine between the upward extension of the side frames.
[00022] As per one aspect of the present invention, the fuel tank assembly has a distinct 2
step profile, ensures the increased volume in the fuel tank assembly and fuel pump is disposed vertically from the top portion of the fuel tank assembly.
[00023] Further, as per one aspect of the present invention, the fuel tank assembly is
disposed in the rear side of the straddle type vehicle having fuel inlet at the rear most side of the straddle type vehicle, which increases the ease of fuel filing in the fuel tank assembly by the riders. Further, the fuel tank assembly is disposed just above the rear fender and the wheel hugger of the rear wheel of the straddle type vehicle. Further, the canister is disposed in the side of the seat rails or pair of side tubes and the hose is

connected to the outlet of fuel tank assembly and the inlet of the canister to channelize the fuel vapor in the canister.
[00024] Further as per one aspect of the present invention, the fuel tank assembly has a
distinct 2 step profile or inverse Z profile, wherein the fuel tank lower wall has a frontal lower portion & a rearward upward portion where the rearward upward portion of the lower wall of the fuel tank is design so as not to interfere with the rear fender of the straddle type vehicle.,. The frontal downward extended portion of the fuel tank assembly extending from rear side to front side of the vehicle is disposed just above the wheel hugger of the rear wheel, which enables enhancing the volume of the fuel tank assembly enabled by the configuration of the distinct 2 step profile of the lower wall of the fuel tank assembly, without interfering with the surrounding components.
[00025] Further, as per one aspect of the present invention, considering the quadrants of
the wheel divided into four quadrants when viewed from the right side of the vehicle, then the upward portion of the fuel tank assembly lies in the first quadrant of the rear wheel (first quadrant corresponding to the top right quadrant followed by 2nd on top left in anti-clock wise direction & so on) and the frontal downward extended portion extending from rear side to front side of the vehicle lies in the second quadrant of the rear wheel. Further, as per one aspect of the present invention, the fuel tank assembly is mounted with respect to the utility box on the rear frame of the straddle type vehicle, and also, the support brackets present at the side of the rear fender supports the fuel tank assembly from both the sides, with respect to the vehicle
[00026] Further, as per one aspect of the present invention, the fuel pump is assembled
from the top of the fuel tank assembly, where at least a portion of the bottom portion of the fuel pump is disposed at least partially below the rearward upward portion of the lower wall fuel tank assembly which lies substantially above the first quadrant of the rear wheel of the straddle type vehicle. Further, as the bottom portion of the fuel pump is disposed at least partially overlapping the frontal downward extended portion of the fuel tank assembly extending from rear side to the front side of the vehicle, thereby, enabling maximum utilization of the fuel present in the fuel tank, ultimately reducing the dead volume in the fuel tank assembly.

[00027] Various other features of the invention are described in detail below with
reference to an embodiment of a two wheeled saddle type scooter vehicle with the accompanying drawings. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the corresponding reference number. With reference to the accompanying drawings, wherein the same reference numerals will be used to identify the same or similar elements throughout the several views.
[00028] Further “front” and “rear”, and “left” and “right” referred to in the ensuring
description of the illustrated embodiment refer to front and rear, and left and right directions as seen in a state of being seated on a seat of the saddle type vehicle. 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. Further, the present subject matter can also be used in any two-wheeler, but for reference, the present subject matter is explained with respect to the step through type vehicle.
[00029] Fig. 1 is an isometric view of the straddle type vehicle as per one embodiment of
the present invention. The described vehicle (100) typically includes a low-framework structure (hereinafter ‘frame’) (not shown), a display unit (not shown), a handle bar assembly (101), and a headlamp assembly (102), a plurality of body panels (103), a front wheel (104), a rear wheel (105), a plurality of suspension units (106), an internal combustion engine (hereinafter ‘engine’) (not shown), a transmission system (107), a seat assembly (108), a utility box (not shown), and a pillion handle (109).
[00030] The frame (not shown) includes a head tube, a main tube, and a pair of side
frames. The main tube extends downwards from an anterior portion of the head tube and then extends rearwards in an inclined manner. The pair of side tubes extends inclinedly upwards from the main tube, in rearward direction of the vehicle. Thus, the frame extends from a front portion (F) to a rear portion (R) of the vehicle (100).

[00031] The display unit (not shown), the handle bar assembly (101), and the headlamp
assembly (102) are disposed above the main tube (not shown), in front portion (F) of the vehicle (100). The display unit is disposed in front of the rider such that the parameters displayed on the display unit are visible to the rider.
[00032] The plurality of body panels (103) covers multiple portions of the frame (not
shown). The plurality of body panels (103) includes a front panel (103a), a leg shield (not shown), a floorboard (103b), an under-seat cover (103c), a left-side panel (103d), a right-side panel (not shown), a left-side trim cover (103e), and a right-side trim cover (not shown). The front panel (103a) and the leg shield (not shown) cover the front portion of the frame (not shown), particularly by covering the head tube and the front portion of the main tube. The floorboard (103b), the under-seat cover (103c), the left-side trim cover (103e), and the right-side trim cover (not shown) shield the center portion of the frame, particularly by covering the center and rear part of the main tube. Similarly, the left-side panel (103d) and the right-side panel (not shown) cover the rear end of the frame, particularly by covering the pair of side tubes.
[00033] The front wheel (104) is disposed in the front portion F of the vehicle (100), under
a front fender (104a). The front fender (104a) is further disposed below the front panel (103a) and the leg shield. The front fender (104a) covers at least a portion of the front wheel (104). The front wheel (104) includes a front hub (104b) and a front tire (104c), removably attached with each other.
[00034] The rear wheel (105) is disposed at the rear portion R of the vehicle (100) under a
rear fender (105a). The rear fender (105a) is further disposed below and between the left side panel (103d) and the right-side panel (not shown). The rear fender (105a) covers at least a portion of the rear wheel (105). The rear wheel (105) includes a rear hub (105b), a rear tire (105c) removably attached with each other.
[00035] The plurality of suspension units (106) includes a front suspension unit (106a)
and a rear suspension unit (106b). The front suspension unit (106a) connects the front wheel (104) to the front portion of the frame through the front hub (104b). The rear suspension unit (106b) connects the rear wheel (105) to the rear portion of the frame through the rear hub (105b). The front and rear suspension unit (106a, 106b) may include

one or more suspension units. For example, the front suspension unit (106a) may include a mono suspension or a left front suspension unit and a right front suspension unit. Similarly, the rear suspension unit (106b) may include a mono suspension or a left-rear suspension unit and a right-rear suspension unit.
[00036] The engine (not shown) is disposed behind the floorboard (103b) and the under-
seat cover (103c) and is supported between the pair of side tubes. The engine is disposed on a swing arm through one or more mounting bosses (not shown) being attached therein. A front end of the swing arm is attached to the rear portion of the main tube and a rear end of the swing arm is attached to the rear wheel (105). The engine generates fuel combustion induced power that is to be transferred to the rear wheel (105) during engine-based propulsion of the vehicle (100). The vehicle (100) may also include a motor (not shown) driven using a battery (not shown) power in case of hybrid electric vehicles.
[00037] The transmission system (107) is a power transfer system of the vehicle (100) that
transmits power either from the engine to the rear wheel (105) or from motor to the rear wheel (105), based on propulsion mode of the vehicle (100) for example electric vehicle or IC engine vehicle. In a hybrid type setup, the vehicle (100) may have multiple propulsion modes such as propulsion by the engine alone, propulsion by the motor alone, and propulsion by both the engine and the motor simultaneously.
[00038] The seat assembly (108) is disposed above the under-seat cover (103c) and
between the left-side panel (103d) and the right-side panel (not shown). The seat assembly (108) is pivotally mounted to the top portion of the under-seat cover (103c). The utility box (not shown) is disposed below the seat assembly (108). The utility box (not shown) can be accessed by opening the seat assembly (103).
[00039] The pillion handle (109) is disposed behind the seat assembly (108) and acts as a
holding support for the pillion rider. In a preferred embodiment, front end of the pillion handle (109) is attached to the rearmost portion of the frame.
[00040] Fig. 2 is the side view of the straddle type vehicle with the fuel tank assembly as
per one embodiment of the present invention. Further, as per one embodiment of the present invention, the fuel tank assembly (201) is mounted with respect to the utility box (not shown) on the rear side of the frame, and also has the fuel inlet provision (202) with

a cap, where the cap opens in an outward direction with respect to the straddle type vehicle, ensuring the ease of fuel filing to the riders. Further, as per one embodiment of the present invention, the fuel tank assembly is mounted above the rear fender and the rear wheel hugger (204). Further, as per one embodiment of the present invention, the canister (203) is disposed at the side of the seat rails, where the canister (203) is connected to the fuel tank assembly (201) through the hose, which ensures the proper channelization of the fuel vapor from the fuel tank to the canister.
[00041] Fig. 3 is an assembled view of the fuel tank assembly with the wheel hugger and
rear fender as per one embodiment of the present invention. Further, as per one embodiment of the present invention, the fuel tank assembly (201) is supported by different supporting means, for example: supporting bracket (302) extending from the rear fender (105a), ensures support to the fuel tank assembly. Further, as per one embodiment of the present invention, the fuel tank assembly (201) has a 2 step profile or the inverse Z profile, where the bottom portion of the fuel tank assembly (201) is further divided into the rearward upward portion (303) and frontal downward extended portion (304) from the vertical axis AA’ with respect to the vehicle, where the vertical axis AA’ is passing through the rear wheel axle and is perpendicular to the ground (horizontal axis) , ensuring increased volume of the fuel tank assembly.
[00042] Fig. 3a is an assembled view of the fuel tank assembly with quadrants of the
wheel as per one embodiment of the present invention. Further, as per one aspect of the present invention, the fuel pump (301) is assembled from the top portion of the fuel tank assembly (201), where the bottom portion of the assembled fuel pump (301) is below the horizontal axis BB’, where the horizontal axis BB’ is parallel to the ground. Further, the bottom portion of the assembled fuel pump (301) passes through the rearward upward portion (303) of the lower wall of fuel tank assembly in longitudinal direction, that is below the rearward upward portion (303) of the lower wall of the fuel tank assembly (201), which enables maximum utilization of the fuel present in the fuel tank assembly (201), thereby reducing the dead volume in the fuel tank assembly. Further, as per one embodiment of the present invention, the rear wheel (105) is further divided into four quadrants (307, 306, 309, 308), where the rearward upper portion (303) of the 2 step profile of fuel tank assembly (201) lies substantially in the first quadrant (307) of the rear

wheel (105), above the rear fender (105a) and the frontal downward extended portion (304) lies in the second quadrant (306) of the rear wheel (105) just above the wheel hugger (204). This configuration ensures the restriction of interference of fuel tank assembly with the surrounding components & enables a compact fuel system design with adequate working or operational dynamic as well as static clearances with vehicle aggregates. As per one embodiment of the present invention, at least a portion of the fuel pump (301) is partially overlapped with at least a portion of the rearward lower portion wall of the fuel tank assembly (201). As per another embodiment, the overlapping portion of the fuel pump is the filter (310).
[00043] The invention helps in overcoming the problem of space constraints, increased
volume of the fuel tank. Reduced dead volume, restriction of interference of the fuel tank assembly with the surrounding components and of the vehicle while maintaining the overall weight and width of the vehicle and ultimately makes it cost effective.
[00044] Advantageously, the embodiments of the present invention, describes the
potential modifications in the fuel tank assembly, where the fuel tank assembly has 2 step profile.
[00045] Many other improvements and modifications may be incorporated herein without
deviating from the scope of the invention.
List of reference symbol:
Fig. 1:
100: Straddle Type Vehicle. 101: Handle Bar Assembly
102: Head Lamp Assembly
103: Plurality of Body Panels
103a: Front Panel
103b: A Floorboard
103c: Under Seat Cover

103d: Left Side Panel
103e: Left Side Trim Cover
104: Front Wheel
104a: Front Fender
104b: Front Hub
104c: Front Tire
105: Rear Wheel
105a: Rear Fender
105b: Rear Hub
105c: Rear Tire
106: Plurality of suspension units
106a: Front Suspension Unit
106b: Rear Suspension Unit
107: Transmission System
108: Seat Assembly
109: Pillion Handle
F: Front Portion
R: Rear Portion
Fig. 2
201: Fuel Tank Assembly 202: Fuel Inlet Provision

203: Canister
204: Rear Wheel Hugger
Fig. 3
302: Supporting Bracket
303: Upward Portion
304: Slanted Downward Extended Portion
AA’: Axis with respect rear wheel axle of the vehicle
Fig. 3a:
301: Fuel Pump
BB’: Horizontal axis which passes through the upward portion of the fuel tank assembly in longitudinal direction (parallel to the ground)
307: First Quadrant
306: Second Quadrant

We Claim;
1. A straddle type vehicle (100), said vehicle (100) comprising:
a front portion (F) and rear portion (R) in said vehicle (100); a front wheel (104) is disposed in said front portion (F), under a front fender (104a); a rear wheel (105) is disposed in said rear portion (R), under a rear fender (105a); a transmission system (107) transfers power from a motor to said rear wheel (105); wherein a fuel tank assembly (201) is configured with a distinct 2 step profile, is disposed above said rear fender (105a) of said rear wheel (105) and a fuel pump (301) is disposed from a top surface of said fuel tank assembly (201) having 2 step profile.
2. The straddle type vehicle (100) as claimed in claim 1, wherein said fuel tank assembly (201) is configured with a 2-step profile with respect to AA’ axis, where said AA’ axis passes through a rear wheel axle and is perpendicular to the ground (horizontal axis).
3. The straddle type vehicle (100) as claimed in claim 1, wherein the lower wall of said fuel tank assembly (100) is divided into a rearward upward portion (303) and frontal downward extended portion (304) with respect to said axis AA’.
4. The straddle type vehicle (100) as claimed in claim 1, wherein said fuel tank assembly (201) is supported by said supporting bracket (302) extending from said rear fender (105a).
5. The straddle type vehicle (100) as claimed in claim 3, wherein said rearward upward portion (303) lies substantially in said first quadrant (307) of said rear wheel (105), above said rear fender (105a).
6. The straddle type vehicle (100) as claimed in claim 3, wherein said frontal downward extended portion (304) lies in said second quadrant (306) of said rear wheel (105), above said wheel hugger (105a).
7. The straddle type vehicle (100) as claimed in claim 1, wherein said fuel pump (301) has at least a bottom portion (310) disposed at least partially below an axis BB’.
8. The straddle type vehicle (100) as claimed in claim 7, wherein said axis BB’ passes through said rearward upward portion (303) of said lower wall of fuel tank assembly (201) in longitudinal direction.