DESC:FIELD
The present disclosure relates to the field of mechanical engineering. In particular, the present disclosure relates to the field of two-wheeled vehicles.
BACKGROUND
Fuel vapour emission is a phenomenon where fuel vapour is formed in the fuel tank due to vaporization of fuel that takes place due to the difference in the temperature within the tank and the ambient temperature. The fuel vapour thus formed needs to be evacuated from the fuel tank to maintain optimum pressure conditions inside the fuel tank. Conventionally, this evacuation is achieved by providing a vent hole in the fuel tank cap, wherefrom the fuel vapour is released into the atmosphere, thus relieving the negative pressure formed inside the fuel tank. This is not desired because when the fuel vapours are released into the atmosphere, it causes loss of valuable fuel besides causing air pollution, as the fuel vapours contain hydrocarbons.
Typically, a system for purging fuel vapours from the fuel tank into the engine of a vehicle includes a canister. The canister is a device that is used to collect the fuel vapour formed inside the fuel tank and supplies the fuel vapour to the intake system of a two wheeled vehicle. The canister usually comprises charged charcoal to adsorb the fuel vapour and supply the adsorbed fuel vapour to the intake system of the two wheeled vehicle. Conventional mounting arrangements for mounting the canister onto the two wheeled vehicle involves the use of a hose routing arrangement that is complicated and lengthy. The successful recovery of the adsorbed fuel vapour is dependent on the proximity of the canister to the fuel tank, and the proximity of canister to point of discharge (intake system). Complicated and lengthy hose routing results in an inefficient recovery of the adsorbed fuel vapour as well as an increased cost associated with the hose routing arrangement.
Hence, there is a need for vehicle having a mounting arrangement for a canister that has a simple configuration that overcomes the above mentioned drawbacks and limitations.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows.
It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
An object of the present disclosure is to provide a system for purging fuel vapours from the fuel tank into the engine, which has a simple configuration so that the use of complicated and lengthy hose routing is avoided.
Another object of the present disclosure is to provide a system for purging fuel vapours from the fuel tank into the engine, which creates favourable conditions for successful recovery of the adsorbed fuel vapour.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure envisages a vehicle having a system for purging fuel vapours from a fuel tank into an engine of a vehicle. The vehicle comprises a frame structure which includes a box assembly frame disposed on an operative front end of the frame structure. A pair of front down tubes extends in an operative downward direction from the box assembly frame, wherein the pair of front down tubes is configured to receive leg guard mounting brackets. The frame structure further comprises a cross member tube that connects the pair to the front down tubes. A pair of rear top tubes extends from the box assembly frame along the longitudinal axis of the vehicle. A pair of rear down tubes extends in an operative downward direction from the rear top tubes. The frame structure further includes a pair of middle tubes extending in an operative downward direction from the box assembly frame, wherein the pair of rear top tubes and the pair of middle tubes are connected to each other by a pair of connecting tubes. The vehicle also comprises a canister that is in fluid communication with the fuel tank and an intake manifold of the engine via a first hose and a second hose respectively. The canister is mounted on one of the pair of middle tubes operatively between the fuel tank and the engine. The canister is configured to receive and adsorb the fuel vapours via a fuel adsorbing block contained therewithin and discharge the fuel vapours into the second hose.
Typically, the canister is mounted on the middle tube via a canister mounting arrangement. In an embodiment, the canister mounting arrangement comprises a primary mounting bracket connected to one of the pair of middle tube. A secondary mounting bracket is connectable to the primary mounting bracket and is configured to receive and support the canister. The canister mounting arrangement further includes resilient bands that are disposed on the canister and configured to be received on the secondary mounting bracket.
Typically, the primary bracket is welded to the middle tube and the secondary bracket is fastened to the primary bracket.
In an embodiment, the secondary bracket has engaging formations configured thereon to receive complementary engaging formations configured on the resilient bands.
Typically, the fluid communication of the canister with the intake manifold is regulated by a control valve.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWING
A system for purging fuel vapours from the fuel tank into the engine, of the present disclosure will now be described with the help of non-limiting accompanying drawing, in which:
Fig. 1A illustrates a side view of a vehicle having a system for purging fuel vapours from the fuel tank into the engine installed thereon, in accordance with an embodiment of the present disclosure;
Fig. 1B illustrates an isometric view of the frame structure with a canister mounted on it which is used in the system of Fig. 1A;
Fig. 1C illustrates an exploded view of a canister mounting arrangement configured on the frame structure of Fig. 1B; and
Fig. 2A and Fig. 2B illustrate sectional views of a purge valve, used in the system of Fig. 1A.
DETAILED DESCRIPTION
Generally, a system for purging fuel vapours from the fuel tank into the engine includes the use of a canister. The canister contains a fuel adsorbing material that adsorbs the fuel vapours formed in the fuel tank of the vehicle, which is desorbed later on and supplied to the intake system of the vehicle. Generally, the canister is mounted on the vehicle body such that it involves the use of lengthy and complicated hose routing to facilitate the fluid communication of the canister with the fuel tank and the intake system of the engine. This is not desired.
The present disclosure envisages a system for purging fuel vapours from the fuel tank into the engine that involves positioning the canister onto a frame structure of the vehicle such that the hose routing to facilitate the fluid communication of the canister with the fuel tank and the intake system of the engine is substantially simplified.
Fig. 1A illustrates a side view of a vehicle 1 having a system 10 for purging fuel vapours from a fuel tank 112 into an engine 120, installed thereon. The system 10 comprises a canister 110 in fluid communication with the fuel tank 112 and an intake manifold 122 of the engine 120 via a first hose (also referred to as inlet conduit 113) and a second hose (also referred to as fuel vapour outlet conduit 114) respectively. The canister 110 is configured to receive and adsorb the fuel vapours via a fuel adsorbing block contained therewithin and discharge the fuel vapours into the second hose. The canister 110 is positioned on the vehicle such that the length of the first hose and the second hose is minimal. In an embodiment, the fuel adsorbing block is charged charcoal. As can be seen the Fig. 1A, a canister 110 is placed operatively below and in close proximity of the fuel tank 112, upstream of an intake manifold 122, operatively above and in close proximity with the engine 120 and a transmission 121, and operatively in front of an air filter 123. The canister 110 is disposed operatively between the fuel tank 112 and the engine 120 such that it is in close proximity with the fuel tank 112 as well as the engine 120. The fluid communication between the fuel tank 112 and the canister 110 is established via the inlet conduit 113, wherein the inlet conduit 113 allows the fuel vapour formed inside the fuel tank to be received in the canister 110. The canister 110 further comprises the fuel vapour outlet conduit 114 and a pressure sensing conduit 115. After the entry of the fuel vapour inside the canister 110, the charged charcoal that is placed inside the canister 110 adsorbs the fuel vapour. After a certain period of time, the charged charcoal inside the canister 110 desorbs the fuel vapour thereby making it available for transfer into the intake manifold 122. A purge control valve (not shown in Fig. 1A) regulates the transfer of the fuel vapour into the intake manifold 122 of the engine 120. More specifically, the fluid communication of the canister 110 with the intake manifold 122 is regulated by the control valve.
Fig. 1B illustrates a perspective view of a frame structure 100 with the canister 110 mounted thereon. The frame structure 100 comprises a box assembly frame 101 disposed on the operative front end of the frame structure 100. The box assembly frame 101 supports the front forks, handlebar, and other components located on the operative front end of a two wheeled vehicle. The frame structure 100 also comprises a pair of front down tubes 102-1, 102-2 extending in an operative downward direction from the box assembly frame 101 that are adapted to receive leg guard mounting brackets, a cross member tube 103 that connects the pair to the front down tubes 102-1, 102-2, a pair of rear top tubes 104-1, 104-2 extending from the box assembly frame 101 along the longitudinal axis of the two wheeled vehicle, a pair of rear down tubes 105-1, 105-2 extending in an operative downward direction from the rear top tubes 104-1, 104-2, and a pair of middle tubes 106-1, 106-2 extending in an operative downward direction from the box assembly frame 101. The pair of rear top tubes 104-1, 104-2 and the pair of middle tubes 106-1, 106-2 are connected to each other by a pair of connecting tubes 107-1, 107-2. In an embodiment, the canister 110 is mounted on the frame structure 100 of the vehicle via a canister mounting arrangement 300. The canister mounting arrangement 300 installed on the frame structure 100 is also indicated in the Fig. 1B. The details of the canister mounting arrangement 300 are explained in the subsequent paragraphs.
Referring to Fig. 1C, the canister mounting arrangement 300 comprises a primary mounting bracket 108 is connected to the middle tube 106-1. In an embodiment, the primary mounting bracket 108 is welded to the middle tube 106-1. The primary mounting bracket 108 is adapted to receive a secondary mounting bracket 109 via fastener such as a bolt. The corresponding nut of the bolt is secured inside the primary mounting bracket 108. Although, a nut-bolt arrangement has been disclosed for connecting primary and secondary mounting brackets, the connecting mechanism is not limited to a nut-bolt arrangement, and any other connecting mechanism for connecting the primary and secondary mounting brackets is well within the ambit of the present disclosure. The secondary mounting bracket 109 is adapted to receive a canister 110. More specifically, the secondary mounting bracket 109 comprises engaging formations 109A adapted to receive complementary engaging formations 111A formed on at least one resilient band 111 disposed on the canister 110. In the present embodiment, the entire assembly including the primary mounting bracket 108, the secondary mounting bracket 109, and the canister 110 is located on the operative top portion of the middle tube 106-1.
Now reference will be made to Fig. 1A, Fig 2A and Fig 2B for describing the operative principle involved in transferring the fuel vapour into the intake manifold 122 of the engine 120. Fig 2A and Fig 2B indicate the sectional views of the purge control valve 200 in first and second operative conditions respectively. The purge control valve 200 comprises a housing 201 provided with a fuel vapour inlet 202, a fuel vapour outlet 203, and a sensing tube 204. The housing 201 further comprises a compression spring 205, one end of which abuts a first operative end 206 of the housing 201, and the other end abuts a diaphragm 208 disposed near a second operative end 207 of the housing 201. The fuel vapour inlet 202 is in fluid communication with the canister 110. The fuel vapour outlet 203 is located on the housing 201 spaced apart from the fuel vapour inlet 202 and near the second operative end 207 of the housing 201 operatively above the diaphragm 208. The sensing tube 204 is connected to the pressure sensing conduit 115 and the fuel vapour outlet 203 is connected to the fuel vapour outlet conduit 114. The sensing tube 204 and the fuel vapour outlet 203 are in fluid communication with the intake manifold 122 of the engine 120 through the pressure sensing conduit 115 and fuel vapour outlet conduit 114 respectively.
During the first operative condition of the purge control valve 200, the canister 110 and the intake manifold 122 are not in fluid communication with each other as the diaphragm 208, under the force of the compression spring 205, tends to obstruct the fuel vapour transfer path. The spring force of the compression spring 205 is so selected that the compression spring 205 tends to retract only after the vacuum pressure inside the intake manifold 122 reaches a predetermined value. As the vacuum pressure inside the intake manifold 122 reaches the predetermined value, the compression spring 205 starts retracting gradually, thereby sweeping the diaphragm 208 along the walls of the housing 201 making the purge control valve 200 finally assume a second operative condition as shown in Fig 2B. When the diaphragm 208 sweeps past the fuel vapour outlet 203, a fluid communication is established between the fuel vapour inlet 202 and the fuel vapour outlet 203 allowing the fuel vapour to be transferred from the canister 110 to the intake manifold 122 which in turn will be transferred to the combustion chamber of the engine 120 for purging along with the air-fuel mixture. Once the vacuum pressure in the intake manifold 122 falls below the predetermined value, the spring force of the compression spring 205 overcomes the forces exerted by the vacuum pressure, allowing the compression spring 205 to regain the original dimensions thereof under normal operating position as shown in Fig 2A. As the compression spring 205 extends to assume its normal operating position, the diaphragm 208 sweeps over the fuel vapour outlet 203 thereby disconnecting its fluid communication with the fuel vapour inlet 202. The spring force of the compression spring 205 is calibrated in line with the predetermined value of vacuum pressure at which the purging of the fuel vapour is desired. The engine 120 can be tuned for the creation of the predetermined value of vacuum pressure at the desired engine speed measured in revolutions per minute.
The canister mounting arrangement 300 of the present disclosure is such that the canister 110 is disposed in the immediate vicinity of the fuel tank 112, the engine 120, and the transmission 121. Because of such an arrangement, the lengthy hose routing from the fuel tank 112 to the canister 110 and from the canister 110 to a carburetor 116 is significantly reduced. As the length of the hose routing required is reduced, the mounting of the canister onto the frame structure 100 becomes simple, and the hose routing required is not very complicated as compared to the conventional canister mounting arrangements. Moreover, the simple configuration of the hose routing also makes it safer to handle the highly inflammable fuel vapour. This results in a simple and a cost effective canister mounting arrangement. Also, the canister mounting arrangement 300 of the present disclosure holds the canister 110 in a secure manner such that minimum vibrations and external loads are transmitted to the canister 110, thus prolonging the working life of the canister 110.
As can be understood from the accompanying figures, the present embodiment of the canister mounting arrangement 300 has been described such that the canister 110 is disposed on the secondary mounting bracket 109 in an operative vertical configuration. However, the disposition of the canister 110 onto the second mounting bracket 109 is not limited to be vertical, and it can be mounted at any angle relative to the secondary mounting bracket 109 in order to overcome the packaging constraints.
TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a system for purging fuel vapours from the fuel tank into the engine:
- which has a simple configuration so that the use of complicated and lengthy hose routing is avoided; and
- which creates favourable conditions for successful recovery of the adsorbed fuel vapour.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation. ,CLAIMS:1. A vehicle having a system for purging fuel vapours from a fuel tank into an engine, said vehicle comprising:
a frame structure which includes:
a box assembly frame;
a pair of front down tubes extending in an operative downward direction from said box assembly frame;
a cross member tube that connects said pair front down tubes;
a pair of rear top tubes extending from said box assembly frame along the longitudinal axis of said vehicle;
a pair of rear down tubes extending in an operative downward direction from said rear top tubes; and
a pair of middle tubes extending in an operative downward direction from said box assembly frame, wherein said pair of rear top tubes and said pair of middle tubes are connected to each other by a pair of connecting tubes; and
a canister in fluid communication with said fuel tank and an intake manifold of said engine via a first hose and a second hose respectively, said canister mounted on one of said pair of middle tubes operatively between said fuel tank and said engine, said canister configured to receive and adsorb said fuel vapours a via fuel adsorbing block contained therewithin and discharge said fuel vapours into said second hose.
2. The vehicle as claimed in claim 1, wherein said canister is mounted on said middle tube via a canister mounting arrangement.
3. The vehicle as claimed in claim 2, wherein said canister mounting arrangement comprises:
a primary mounting bracket connected to one of said pair of middle tube;
a secondary mounting bracket connectable to said primary mounting bracket, said secondary mounting bracket is configured to receive and support said canister; and
at least one resilient band disposed on said canister and configured to engage said secondary mounting bracket.
4. The vehicle as claimed in claim 3, wherein said primary bracket is welded to said middle tube.
5. The vehicle as claimed in claim 3, wherein said secondary bracket is fastened to said primary bracket.
6. The vehicle as claimed in claim 5, wherein said secondary bracket has engaging formations configured thereon to receive complementary engaging formations configured on said at least one resilient band.
7. The vehicle as claimed in claim 1, wherein the flow of fuel vapour from said canister into said intake manifold is regulated by a purge control valve.
8. The vehicle as claimed in claim 1, wherein the flow of fuel vapour from said canister into said carburetor is regulated by a one way valve.