MOTORCYCLE
FIELD OF THE INVENTION
The present invention relates to a motorcycle, and more particularly
to a location of a canister in a motorcycle.
BACKGROUND
Typically, a portion of the fuel stored in a fuel tank of a motorcycle
gets evaporated continuously to the atmosphere through a breather hole provided in a fuel tank cap, thereby contributing to atmospheric emissions. In order to arrest the loss of fuel due to evaporation and in order to control evaporative emissions from the fuel tank, a fuel evaporation gas emission suppression device using activated carbon, and commonly referred to as 'canister' is provided. Therefore, use of a canister aids in controlling hydrocarbon emissions. The canister also enables reuse of the evaporated fuel without releasing it to the atmosphere.
It is well known that activated carbon, a major constituent of the canister, has a tendency to adsorb evaporated fuel when cooled and desorb the evaporated fuel when warmed up. Thus, temperature at which the canister is maintained is important from the point of view of efficient performance of the canister. Specifically, it is preferred that the canister be warmed up during the operation of engine, and be cooled down when the engine is turned off, for optimal performance of the canister. Also, it is desirable to mount the canister close to the fuel tank so that a need for providing a lengthy/long discharge hose can be done away with.

In a known art, the canister is arranged in front of the engine, in a manner such that it is continuously cooled by the incoming air as the motorcycle traverses in a forward direction. However, in such an arrangement, as the canister is continuously cooled during the operation of the engine, a scope for sufficient heating of the canister, so that the adsorbed fuel vapours get effectively desorbed, is minimised. Also, this arrangement involves direct exposure of the canister to sunlight, and therefore causes the canister to get warmed up even when the engine is turned off, which is undesirable.
In another known art, the canister is disposed above a horizontally mounted engine where sufficient space is available for the arrangement of the canister around a cylinder body of said engine.
However, a suitable location for the canister in a motorcycle comprising a vertically mounted engine is desired, where very little space is available for the arrangement of the canister around a cylinder body of the engine, so that the canister meets its intended performance.
Moreover, it is desirable to optimally locate the canister in a motorcycle comprising a vertically mounted engine in a manner such that the location of the canister does not affect the functionality and serviceability of the adjacent/ interfacing parts, including a cylinder head and cylinder body of the engine.

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SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an
optimal mounting location for a canister in a motorcycle comprising a vertically mounted engine.
It is another object of the invention to provide a motorcycle including a canister that is arranged to be warmed up during the operation of the engine, and arranged to be cooled down when the engine is turned off.
It is yet another object of the invention to provide a motorcycle including a canister that is arranged to be secured from damage due to sunlight, water entry, and accidental hit by foreign bodies.
It is still another object of the invention to provide a motorcycle including a canister that is arranged in a manner such that the location of the canister does not affect the functionality and serviceability of the adjacent/ interfacing parts, including a cylinder head and cylinder body of the engine.
The present subject matter discloses a motorcycle which includes a frame main tube, a vertically mounted engine (hereinafter 'engine'), a fuel tank, a throttle body, an air filter and an evaporation controlling means namely a canister. The engine including a crankcase, a cylinder body provided above the crankcase and a cylinder head provided to the cylinder body, disposed under said frame main tube, acts as a power source of the

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motorcycle. The fuel tank arranged over the frame main tube and above the engine stores fuel to be supplied to the engine. The throttle body disposed at least partially below the fuel tank and behind the cylinder body and cylinder head and in front of the air filter supplies air fuel mixture to the engine. The air filter arranged behind the throttle body supplies clean air to throttle body. The canister is disposed in a recess formed between a lower portion of the fuel tank and the frame main tube, towards a rear portion of the fuel tank, at least partially above the throttle body and substantially behind the cylinder head.
Further, the canister comprising at least a tank port and at least a purge port and connected to the fuel tank and the throttle body, suppresses fuel vapour generated by evaporation of the fuel in the fuel tank from being emitted to the atmosphere.
In accordance with the present invention, the canister is arranged at least partially above the throttle body and substantially behind the cylinder head, accordingly, the canister is arranged to be warmed up by the incoming air carrying away heat from the cylinder body towards a rear portion of the motorcycle, when the motorcycle traverses in a forward direction. Moreover, the canister being disposed substantially behind the cylinder head, it does not get heated due to the heat radiated by the engine when the engine is turned off. Also, the canister is seldom exposed to direct sunlight as the fuel tank substantially covers an upper portion of the canister, and accordingly, the canister is arranged to be cooled down

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when the engine is turned off. Additionally, a longitudinal axis of the canister arranged substantially obliquely with respect to a ground surface facilitates quick draining of the fuel, if it enters inadvertently.
Also, the canister being disposed in a recess formed between a lower portion of the fuel tank and the frame main tube, accordingly the canister is secured from water entry and accidental hit by foreign bodies.
The disclosed mounting arrangement for the canister also helps in minimizing hose length of a tank hose and a purge hose, as the canister is disposed below the fuel tank and above the throttle body, thereby reducing the manufacturing cost and further enhancing the performance of the evaporative emission control system, by reducing evaporation losses through the walls of fuel hoses such as the tank hose and purge hose.
Further, the canister being disposed substantially behind the engine, the location of the canister does not interfere with the cylinder head of the engine, thereby facilitating the serviceability of the cylinder body and cylinder head of the engine.
Thus, the present invention aids in providing an optimal mounting location for the canister in a motorcycle comprising a vertically mounted engine.
Summary provided above explains the basic features of the invention and does not limit the scope of the invention. Additional detailed information related to the enablement of the invention will be provided in

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the detailed description and accompanying claims. Scope of the invention shall be based on the claims provided.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 illustrates a typical motorcycle including a canister in accordance
with the present invention.
Figure 2 illustrates a top view of a cut section of a fuel tank depicting the arrangement of the canister in accordance with the present invention.
Figure 3 illustrates a side view of body frame of motorcycle showing arrangement of the canister in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Different embodiments for an arrangement for a canister in a front
portion of a motorcycle in accordance to the present invention will be described hereunder with reference to the accompanying drawings. Various features of said arrangement in accordance to the present invention will become discernible from the following description set out hereunder. It is to be noted that terms "upper", "lower", "right", "left", "front", "forward", "rearward", "downward", "upward", "top", "bottom" and like terms are used herein based on the illustrated state or in a standing state of the motorcycle with a driver riding thereon. 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.

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First a description is made of an entire schematic structure of a motorcycle 10. Figure 1 is a left side view of the motorcycle 10.
As may be seen in Fig.1, motorcycle 10 includes a body frame 20 that defines the skeleton of the motorcycle 10. The motorcycle 10 includes a front wheel 30, front forks 31, a vertically mounted engine (hereinafter 'engine') 40, a throttle body 50, an air filter 60 (Refer to Fig.3), a seat 70, a rear wheel 80, a fuel tank 90 and a canister 100. Further, a head pipe 21 is provided at a front end of the body frame 20. Furthermore, a body frame main tube 22 extending rearwards from the head pipe 21 forms a front portion of the body frame 20. The fuel tank 90 is arranged over the body frame main tube 22. The seat 70 is arranged immediately behind the fuel tank 90 and is supported by the body frame 20. The engine 40 including a crankcase 41, cylinder body 42 and a cylinder head 43, the throttle body 50 and the air filter 60 are also attached to the body frame 20.
The front wheel 30 is rotatbly supported by the front forks 31 coupled to the body frame 20. The front forks 31 are coupled to a steering shaft (not shown) through a bridge 23 which is supported on the head pipe 21. The steering shaft is supported so as to be rotatable left and right with respect to a travelling direction of the motorcycle 10.
The engine 40 is a power unit that generates drive force of the motorcycle 10. The engine 40 includes a crankcase 41, cylinder body 42 and a cylinder head 43 and generates power which is transmitted to the rear wheel 80 through a drive chain. The engine 40 is an air cooled engine

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and is supported by, among other parts by a lower portion of the body frame main tube 22.
The throttle body 50 supplies an air fuel mixture to the engine 40. In this embodiment a carburettor is constituted as the throttle body 50. It is to be noted that not only a carburettor but also an electronic fuel injection (EFI) device may be used. The throttle body 50 is located behind the engine 40 and at least partially below the fuel tank 90.
Referring to Fig.3 the air filter 60 is arranged below a seat frame (not shown) and behind the throttle body 50. The air filter is coupled to the throttle body 50. The air filter supplies claen air to the throttle body 50. The air taken from the air filter 60 is mixed with the fuel by the throttle body 50 and thereafter inhaled into the cylinder body 42.
The fuel tank 90 reserves fuel to be supplied to the engine 40 through the throttle body 50. The fuel tank 90 is arranged over the body frame main tube 22 and above the engine 40.
Typically, a portion of fuel from the fuel tank 90 evaporates continuously to the atmosphere through a breather hole provided in a fuel tank cap, thereby contributing to atmospheric emissions. In order to arrest the loss of fuel due to evaporation and in order to control evaporative emissions from the fuel tank 90, an evaporative emission controlling means in the form of the canister 100 is provided. The canister 100 is a cylindrical member which has activated carbon as a constituent that aids in adsorbing fuel vapours. Further, the canister 100 includes a plurality of

ports including at least a tank port 101, and a purge port (not shown) adjacent to each and a least a fresh air intake port 103. The tank port 101 is connected to a discharge tube 105 of the fuel tank 90 to receive the fuel vapours from the fuel tank 90; the purge port is connected to purge hose 102 through which the desorbed fuel vapours are sent to the throttle body 50.
As shown in Fig 2 the canister 100 is arranged in a recess 200 formed between a lower portion of the fuel tank 90 and the body frame main tube 22. The canister 100 is arranged in a manner such that a longitudinal axis of the canister 100 is arranged substantially obliquely with respect to a ground surface.
Specifically, the arrangement of the canister 100 can be made out from Figure 3. The canister 100 is attached to an attachment structure (not shown) provided on the body frame main tube 22. As shown in Fig.3, the canister 100 is arranged at least partially below the fuel tank 90, substantially behind the cylinder body 42 and cylinder head 43, at least partially above the throttle body 50 and in front of the air filter 60. Further, the canister 100 is arranged obliquely in a manner such that the tank port 101 and the purge port faces the head pipe 21. Furthermore, the canister 100 is arranged between the fuel tank 90 and the throttle body 50 so that the canister 100 is neither far from the vapour discharge port (not shown) in the fuel tank 90 nor from the throttle body 50 thereby minimizing total length of the discharge tube 105 and the purge hose 102 connected to the

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discharge port and to the purge port respectively. Minimising total length of the discharge tube and the tank hose helps in reducing evaporative emission through permeation and also in improving cost effectiveness of the system.
Thus, the fuel vapours generated and tapped in the fuel tank 90 is passed through the discharge tube 105 of the fuel tank 90 to the canister 100. The fuel vapours passed through the discharge tube 105 and into the canister get adsorbed in the activated carbon present inside the canister 100. When the canister 100 gets sufficiently warned up the adsorbed vapours are sent to the throttle body 50 through the purge hose 102 by a purging action. Further, the canister 100 is also provided with valves to check the flow of fuel from the fuel tank 90 into the canister 100.
In accordance with the present invention, the canister 100 is arranged at least partially above the throttle body 50 and substantially behind the cylinder head 43, accordingly, the canister 100 is arranged to be warmed up by the incoming air carrying away heat from the cylinder body 42 towards a rear portion of the motorcyclelO, when the motorcycle 10 traverses in a forward direction
Also, in the above-mentioned configuration, the degree of freedom in layout of the canister is enhanced, thereby easing the serviceability of the canister and the nearby parts including the cylinder body 42 and the cylinder head 43 of the engine 40.

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The above described location and arrangement of the canister 100 does not affect the serviceability of cylinder head 43 as the canister 100 is located behind the cylinder head 43.
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 motorcycle (10) ) having a vertically mounted engine (40) and including an evaporative emission controlling means, said motorcycle (10) comprising:
a body frame main tube (22) extending rearwards from a head pipe (21);
the vertically mounted engine (40) including a crankcase (41) that houses a crankshaft, a cylinder body (42) provided above the crankcase (41), and a cylinder head (43) provided to the cylinder body (42) and disposed under said body frame main tube (22);
a fuel tank (90) disposed over the frame main tube (22);
a throttle body (50) disposed at least partially below the fuel tank (90) and substantially behind the vertically mounted engine (40);
an air filter (60) disposed substantially behind the throttle body (50) and;
a canister (100) connected to the fuel tank (90) and the throttle body (50), to suppress vapours generated by the evaporation of fuel in the fuel tank (90) from being emitted to atmosphere;
wherein the canister (100) is disposed in a recess (200) formed between a lower portion of the fuel tank (90) and the body frame main tube (22), towards a rear portion of the fuel tank (90), at least

partially above the throttle body (50), substantially behind the cylinder head (43), and in front of the air filter (60).
2. The motorcycle (10) as claimed in claim 1, wherein the canister (100) comprises a plurality of ports, including a tank port (101), a purge port, and a fresh air intake port (103).
3. The motorcycle (10) as claimed in claim 1 or claim 2, wherein the canister (100) is disposed in the recess (200) in a manner so that the tank port (101) and the purge port faces the head pipe (21).
4. The motorcycle (10) as claimed in claim 1, wherein the canister (100) is disposed in the recess (200), in a manner so that a longitudinal axis of the canister (100) is displaced substantially obliquely to a ground surface.