TECHNICAL FIELD
[0001] The present subject matter relates generally to a scooter type two-wheeled vehicle. More particularly, the present subject matter relates to an evaporative emission control system for the scooter type two-wheeled vehicle.
BACKGROUND
[0002] In recent times, there has been an increasing demand to control evaporative emissions from automobiles, for example from two wheeled motorcycles including scooter type motorcycles, in view of the stringent environmental norms. Therefore, in order to control evaporative emissions, an evaporative emission control device, commonly referred to as canister is being increasingly used. Use of a canister aids in controlling evaporative emissions. The canister also enables reuse of the evaporated fuel without releasing it to the atmosphere.
[0003] Activated carbon, a major constituent of the canister plays an important role in controlling evaporative emissions. Activated carbon has a tendency to adsorb and store more amount of evaporated fuel when cooled, and desorbs the evaporated fuel easily when warmed up. Thus, temperature at which the canister is maintained is important from the point of view of efficient performance of the. canister. Moreover, it is important to ensure that hoses emerging from the canister are securely routed so that probability of snapping of the hoses is minimized. Further, it is also important to ensure that fuel entry into the canister is prevented when the scooter type vehicle falls or experiences a jerk in bumpy conditions or

when sudden brakes are applied, or to prevent a sudden slosh of fuel into the canister from the fuel tank when the vehicle is banking or when the vehicle is crossing a gradient. Furthermore, it is important to ensure that the arrangement of the canister does not affect serviceability of frequently serviceable parts such as tyres, carburetor, and air filter etc.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to reference like features and components.
[0005] Fig. 1 (a) shows a perspective view of a scooter-type two-wheeled vehicle 100.
[0006] Fig. 1 (b) shows a side view of the scooter-type two-wheeled vehicle 100 in accordance with a first embodiment of the present subject matter.
[0007] Fig. 2 (a) shows an evaporative emission control system 200 of the scooter type two-wheeled vehicle 100, in accordance with a first embodiment of the present subject matter.
[0008] Fig. 2 (b) shows the evaporative emission control system 200 of the scooter type two-wheeled vehicle 100, in accordance with an embodiment of the present subject matter.

[0009] Fig. 2 (c) shows another view of the evaporative emission control system 200, in accordance with an embodiment of the present subject matter.
[00010] Fig. 2 (d) shows yet another view of the evaporative emission control system 200, in accordance with an embodiment of the present subject matter.
[00011] Fig. 3 (a) shows a disassembled view of an evaporative emission control unit 300-1, in accordance with an embodiment of the present subject matter.
[00012] Fig. 3 (b) shows an assembled view of an evaporative emission control unit 300-2, in accordance with an embodiment of the present subject matter.
DETAILED DESCRIPTION
[00013] Typically, in two-and three-wheeled vehicles, the carbon vapor canister acts as an essential part in the evaporative emission control system. For instance, the layout constraint in case of such two-wheeled vehicles, particularly due to space limitations, makes the packaging of the canister a challenging task. Generally, the fuel vapor generated in a fuel tank of the two-wheeled vehicle is tapped and passed to the carbon vapor canister through a discharge tube. Such vapors tend to be adsorbed in the carbon inside the canister. The adsorbed vapors are in turn sent to a throttle body or carburetor of the induction system of an IC engine of the two-wheeled vehicle, by a purging action. Typically, the carbon vapor canister is positioned in such a manner that it is protected from environmental disturbances and that its core functionality is not affected under

any circumstances. Further, the canister should be mounted in such a location that optimal serviceability of adjacent/ interfacing parts/systems are always ensured.
[00014] Hence, it has always been a challenge to provide an optimal mounting location for the evaporative emission control system in a two-wheeled vehicle, more particularly, for a scooter type two-wheeled vehicle. More importantly, one or more factors affect the optimal functioning of the evaporative emission control system. For example, locating the canister of the evaporative emission control system at a position away from the fuel tank often makes the length of hose carrying tapped fuel vapors from the fuel tank to the canister longer. This largely affects the optimal performance of evaporative emission control, as larger the hose length, greater the chances of fuel vapors evaporating to atmosphere. Further, increase in length of hoses, or increase in number of bends in hoses may lead to condensation of fuel in the hoses and reduced effectiveness of purging.
[00015] Similarly, in case of conventional evaporative emission control systems, locating the canister often turn out to be cumbersome that makes assembly of the components of the evaporative emission control system difficult. Moreover, such an assembly process may lead to operator fatigue. Thus, locating the canister in an optimal location that makes the assembly process less cumbersome is necessary. Furthermore, locating the canister too close to the IC engine of the scooter type two-wheeled vehicle could make the canister to become too hot. Similarly, locating the canister too far away from the IC engine of the scooter type two-wheeled vehicle could make the canister to become too cold.

[00016] The present subject matter provides an evaporative emission control system including a canister that overcomes the above stated problems of the conventional evaporative emission control system. In an embodiment, the canister of the evaporative emission control system of the present subject matter is mounted in the vicinity of a muffler assembly of the scooter type two-wheeled vehicle. Mounting the canister at such a location ensures optimum temperature for optimal operation of the canister. Moreover, the heat provided by the exhaust system parts is sufficient for proper purging action of the canister. Further, the canister is located in such a manner that the incoming wind is made to pass through the canister mounting location that ensures sufficient cooling of the canister.
[00017] Moreover, the canister is located in such a position that in case of liquid fuel entry or water entry, the liquid can be safely discharged to the ground away from the engine and other exhaust system parts. Further, the length of the hose connecting the fuel tank and the canister is made optimal such that there are minimal losses of fuel vapor to the atmosphere. Since the canister mounting bracket is easily accessible & visible, the mounting location of the canister as described in the present subject matter provides ease of assembly of the canister and the associated hose connections, thereby reducing operator fatigue and ensuring optimal location of one or more hose clips.
[00018] The present subject matter provides a two-wheeled vehicle, more particularly, a scooter type two-wheeled vehicle having a main tube frame extending downwards from a steering column. The scooter type two-wheeled

vehicle includes an engine disposed along a longitudinal axis of the two-wheeled vehicle. In an embodiment, the engine along with a cylinder head is mounted at the end of the main tube frame on a toggle link below rear frame tube members. In one embodiment, a fuel tank is disposed on a rear side of the two-wheeled vehicle. In an embodiment, the fuel tank is disposed substantially rearward of a utility box that is disposed forwardly underneath a seat of the two-wheeled vehicle. In an embodiment, the carbon vapor canister that adsorbs the evaporated fuel vapors contained in the fuel tank is connected to the fuel tank through at least one hose. In an embodiment, the canister is mounted to a muffler-mounting bracket and disposed in a space formed between a muffler assembly and a utility box, and adjacent to the rear wheel of the two-wheeled vehicle. In one embodiment, a part of the canister extends substantially upwardly and towards a RH side of the utility box when viewed from rear of the two-wheeled vehicle. In an embodiment, the canister is oriented in such a manner that a central longitudinal axis of the canister is substantially parallel to the top surface of muffler-mounting bracket. Further, in one embodiment, the canister is connected to an air-fuel metering system through a second hose, for example, a purge hose.
[00019] Further, in an embodiment of the present subject matter, the canister is oriented in such a manner that at least one drain port of the canister is positioned to be at a lowermost point as compared to other ports of the canister. Thus, the canister is not only positioned at an optimal location, but is oriented optimally to enhance the overall functioning of the evaporative emission control system of the scooter type two-wheeled vehicle.

[00020] In an embodiment, the canister is mounted on a muffler-mounting link using at least one mounting bracket that is welded or fastened with the help of one or more fasteners. In another embodiment, the canister is mounted towards a rearward bottom of the utility box. For example, a bracket extending from the rearward bottom of the utility box enables mounting of the canister. Further, in another embodiment, the canister is capable of being mounted to an engine crankcase or a cover magneto by means of at least one bracket attached to the crankcase. In yet another embodiment, the canister of the present subject matter is capable of being mounted to a rear fender using a bracket fastened to the rear fender by means of one or more fastening elements.
[00021] These and other advantages of the present subject matter would be described in greater detail in conjunction with the figures in the following description.
[00022] Figo 1 (a) shows a perspective view of a scooter-type two-wheeled vehicle 100. In an embodiment, the scooter-type two-wheeled vehicle 100 includes a body frame assembly (not shown), for example an underbone body frame assembly, made of steel or aluminium alloy and covered by various covers. Further, in one embodiment, the body frame assembly supports a steering assembly including a steering shaft (not shown), and a handle bar assembly 101 in a front portion thereof. A front fork 102 is rotatably supported on the steering shaft. In an embodiment, the handle bar assembly 101 provided above the front fork 102 allow steering of a .front wheel 103. A headlight assembly 105 is supported on the handle bar. assembly 101. Further, in an embodiment, a front

cover 106 is provided to cover a forward facing side of the body frame assembly, and a front fender 107 is provided to cover an upper portion of the front wheel 103.
[00023] In a similar manner, left and right side covers 108 are disposed to cover left and right side surfaces of a rear portion of the body frame assembly. A seat 122 is disposed above the left and right side covers 108. In an embodiment, a fuel tank (not shown in Fig. 1 (a)) is arranged under the seat 122. An engine (not shown) is arranged downwardly and in front of the fuel tank. An air fuel mixture sent in by a throttle body or carburetor (not shown in Fig. 1 (a)) to a combustion chamber of the engine powers the engine. Furthermore, combustion gases generated by the engine is let out as exhaust from a muffler assembly 127 extending along a right hand side of the scooter type two-wheeled vehicle 100. In an embodiment, the two-wheeled vehicle 100 of the present subject matter includes a toggle link (not shown) that is supported swingably on a lower side of the left and right side covers 108. A suspension (not shown) is mounted between the body frame assembly and the engine. A rear wheel 130 is supported on a rear portion of the engine.
[00024] Fig. 1 (b) shows a side view of the scooter-type two-wheeled vehicle 100 in accordance with a first embodiment of the present subject matter. In an embodiment, an engine 132 of the scooter type two-wheeled vehicle 100 is mounted substantially horizontally to a ground surface and along a longitudinal axis of the two-wheeled vehicle 100. In an embodiment, a muffler assembly 127 extends rearwardly from an exhaust port (not shown) of the engine 132 on the RH

side of the rear wheel 130. The muffler assembly 127 extends in such a manner that a substantial space is formed between a top portion of the muffler assembly 127 and a bottom portion of a fuel tank assembly 144. In an embodiment, a canister 140 is optimally disposed in such a space formed between the top portion of the muffler assembly 127 and the bottom portion of the fuel tank assembly 144. In one embodiment, the fuel tank assembly 144 is disposed substantially above a rear fender 136 and behind a utility box 142. The utility box 142 and the fuel tank assembly 144 are disposed substantially below a seat 122. In an embodiment, the fuel tank assembly 144 is mounted to at least one rear frame member 134. The canister 140 is optimally located rearwardly above the engine 132 and forwardly upward of the muffler assembly 127, thus receiving necessary heat for effective purging. Further, in yet another embodiment, the fuel tank assembly 144 is capable of being disposed underneath a floor board 138 of the scooter type two-wheeled vehicle 100.
[00025] Fig. 2 (a) shows an evaporative emission control system 200 of the scooter type two-wheeled vehicle 100, in accordance with a first embodiment of the present subject matter. In an embodiment, the evaporative emission control system 200 includes the canister 140 mounted on to a muffler mounting link 202 of the muffler assembly 127. In an embodiment, the canister 140 is disposed substantially below and extending towards a right hand side of the fuel tank assembly 144 when viewed in vehicle width direction. In one embodiment, the fuel vapors escaping out of the fuel tank assembly 144 are tapped by means of a vapor tapper unit 206 disposed substantially upward of the fuel tank assembly

144. The tapped fuel vapors are routed to the canister 140 by the vapor tapper unit 206 through at least a first hose 204 connecting the vapor tapper unit 206 of the fuel tank assembly 144 and the canister 140.
[00026] Fig. 2 (b) shows the evaporative emission control system 200 of the scooter type two-wheeled vehicle 100, in accordance with an embodiment of the present subject matter. The carbon particles disposed inside the canister 140 adsorbs the fuel vapors entering the canister 140 from the vapor tapper unit 206. Any fuel particles that are adsorbed in the canister 140 are routed to a throttle body (not shown) of the engine (not shown) by means of a second hose 214 that is disposed between the canister 140 and the throttle body. Further, any fuel particles that are not adsorbed by the canister 140 are let out to atmosphere via either an air vent or a port (not shown). In an embodiment, the canister 140 is mounted to the muffler mounting link 202 (not shown in Fig. 2 (b)) by means of a canister mounting bracket 212. In an embodiment, the canister mounting bracket 212 is mounted on to the muffler mounting link 202 by means of one or more fastening elements (not shown). In another embodiment, the canister mounting bracket 212 is welded on to the muffler mounting link 202. In an embodiment, the first hose 204 that runs between the vapor tapper unit 206 and the canister 140 is guided by means of at least one guided coupled to a fuel cock 208 of the fuel tank assembly 144 (not shown in Fig. 2 (b)). In an embodiment, the fuel (liquid) from the fuel tank assembly 144 is routed to the fuel cock 208 by means of a third hose 210.
[00027] Fig. 2 (c) shows another view of the evaporative emission control system 200, in accordance with an embodiment of the present subject matter. In an

embodiment, muffler mounting link 202 is disposed rearwardly to the muffler assembly 127 when viewed from a right hand side of the two-wheeled vehicle 100. Further, the canister mounting bracket 212 (not shown) is also disposed rearwardly to the muffler mounting link 202, thereby ensuring that the canister mounting bracket 212 is not exposed when viewed from vehicle sideward direction. Such a mounting of the canister mounting bracket 212 ensures that the bracket 212 is not affected by external factors such as rain water, slosh, and mud. Further, such a mounting of the canister 140 also ensures that the mounting bracket 212 is not seen when viewed from sideward direction of the two-wheeled vehicle 100. Further, in an embodiment, the first hose 204 is disposed in such a manner that the fuel vapors are routed under the influence of pressure that is built up inside the fuel tank assembly 144 due to formation of fuel vapors, from the vapor tapper unit 206 to the canister 140. Similarly, the second hose 214 is disposed in such a manner that the fuel vapors are routed due to engine suction pressure from the canister 140 to the throttle body 216. In another embodiment, a purge valve (not shown) is disposed between the canister 140 and the throttle body 216. Similarly, a roll over valve (not shown) is disposed between the vapor tapper unit 206 and the canister 140.
[00028] Fig. 2 (d) shows yet another view of the evaporative emission control system 200, in accordance with an embodiment of the present subject matter. The canister 140 includes a hose guide 218 for guiding the second hose 214 routed between the canister 140 and the throttle body 216 (not shown in Fig. 2 (d)). In an

embodiment, the hose guide 218 is integrated with a canister boot member (not shown) that is circumferentially disposed around the canister 140.
[00029] Fig. 3 (a) shows a disassembled view of an evaporative emission control unit 300-1, in accordance with an embodiment of the present subject matter. Fig. 3 (b) shows an assembled view of an evaporative emission control unit 300-2, in accordance with an embodiment of the present subject matter. In an embodiment, the evaporative emission control unit 300-1 as illustrated in Fig. 3 (a) includes a canister boot member 302 that is circumferentially disposed around the canister 140 in such a manner that the canister 140 is held stably without being disturbed due to the vibrations generated by the muffler assembly 127 to which the canister 140 is mounted. In an embodiment, the canister boot member 302 includes a first receiving portion 304 for receiving the canister mounting bracket 212 (not shown) that is coupled to the muffler mounting link 202 (not shown). In an embodiment, the canister 140 includes at least two nozzles, viz., a first nozzle 306 for housing the first hose 204 connecting the canister 140 to the vapor tapper unit 206, and a second nozzle 308 for housing the second hose 214 connecting the canister 140 to the throttle body 216.
[00030] Although the subject matter has been described in considerable detail with reference to certain embodiments thereof, other embodiments are possible. It is to be understood that the aspects of the embodiments are not necessarily limited to the features described herein. Rather, the features are disclosed as embodiments of the evaporative emission control system 200 of the scooter type two-wheeled vehicle 100, and an evaporative emission control unit 300-1, 300-2.

We claim:
1. A two-wheeled vehicle (100) having an evaporative emission control system (200) for effectively purging fuel vapors formed inside a fuel tank assembly (144) of said two-wheeled vehicle (100), said two-wheeled vehicle (100) comprising:
a main tube frame extending downwardly from a steering column;
at least one rear frame member (134) extending rearwardly upward from said main tube frame;
an engine (132) mounted substantially horizontally to a ground surface and along a longitudinal axis of said vehicle (100), said engine (132) disposed at an end of said main tube frame below said rear frame member (134);
said fuel tank assembly (144) disposed substantially rearwardly of a utility box (142), said fuel tank assembly (144) and said utility box (142) disposed substantially underneath a seat (122) of said vehicle (100); wherein said evaporative emission control system (200) of said vehicle (100) comprises:
an evaporative emission control unit (300-1, 300-2) including a canister (140) for adsorbing evaporated fuel vapors from the fuel tank assembly (144), said canister (140) is disposed in a space formed between a muffler assembly (127) and said utility box (142), and wherein said canister (140) is adjacent to a rear wheel (130) of said vehicle (100) and substantially adjoining said engine (132).
2. The two-wheeled vehicle (100) as claimed in claim 1, wherein said canister (140) is connected to said fuel tank assembly (144) through at least a first hose

(204), wherein said first hose (204) carries fuel vapors tapped by a vapor tapper unit (206) of said fuel tank assembly (144) to the canister (140).
3. The two-wheeled vehicle (100) as claimed in claim 1, wherein the canister (140) is oriented substantially inclined and extending towards a vehicle widthwise direction for allowing an incoming wind to be directed towards said canister (140) for providing sufficient cooling to the canister (140).
4. The two-wheeled vehicle (100) as claimed in claim 1 or 2, wherein length of said first hose (204), and a second hose (214) for carrying fuel particles that are adsorbed in the canister (140) are routed to a throttle body of the engine (132) are made optimal for minimizing loss of fuel vapor to the atmosphere.
5. The two-wheeled vehicle (100) as claimed in claim 1, wherein said canister (140) is mounted to a muffler mounting link (202) of said muffler assembly (127) by means of a canister mounting bracket (212), and wherein said canister (140) is oriented with a central longitudinal axis of the canister (140) substantially parallel to a top surface of said muffler-mounting bracket (202).
6. The two-wheeled vehicle (100) as claimed in claim 1, wherein said canister (140) is mounted towards a rearward bottom of the utility box (132) with a bracket extending from the rearward bottom of the utility box (132) for mounting said canister (140).
7. The two-wheeled vehicle (100) as claimed in claim 1, wherein the canister (140) is mounted to at least one of a crankcase and a cover magneto of said engine (132) by means of at least one engine mounting bracket.

8. The two-wheeled vehicle (100) as claimed in claim 1, wherein the canister (140) is mounted to a rear fender by means of a rear fender mounting bracket.
9. The two-wheeled vehicle (100) as claimed in claim 1 or 5, wherein the canister mounting bracket (212) is capable of being received in a canister boot member (302), which supports the canister (140) by circumferentially wrapping a body of said canister (140), and wherein said canister boot member (302) is provided with a radially disposed slot (304) to receive the canister mounting bracket (212).
10. The two-wheeled vehicle (100) as claimed in claim 9, wherein said canister
boot member (302) is integrated with a hose guide (218) for securely guiding said
at least first hose (204) and said at least second hose (214).