AN AIR INTAKE CHAMBER

FIELD OF THE INVENTION

[0001] The present subject matter relates generally to an intake system, and more particularly, to an air intake chamber for a straddle type vehicle.

BACKGROUND OF THE INVENTION

[0002] The induction system of an internal combustion engine for a straddle type vehicle comprises of a carburettor, an air intake chamber and an intake conduit. The carburettor is made of a die cast body of complex shape into which a series of carefully machined openings are provided. A typical carburettor, made of aluminium or an aluminium alloy, is connected to the intake conduit on one side and the air intake chamber on the other side through known joining mechanisms. It mixes the air supplied by the air intake chamber with the fuel in a suitable ratio to form a combustible air-fuel mixture. At least one intake port is located in the cylinder head of the engine which is connected with the carburettor through the intake conduit. The air intake chamber supplies filtered environmental air to the carburettor and reduces induction noise. The air-fuel mixture of carburettor is supplied to the combustion chamber of the engine cylinder through intake valves for ignition. The vehicle is then powered by controlled combustion of the combustible charge.

[0003] Various types of carburettors are known including a side-draught carburettor, up-draught carburettor or a down-draught carburettor differentiated on the basis of direction of flow of environmental air. The type of carburettor used in a vehicle depends upon the location of intake port of the internal combustion engine. In the down-draught carburettor, filtered air from the air intake chamber enters from the top of the carburettor, mixes with fuel and moves downwards to the cylinder head assembly through the intake conduit. On the other hand, in a side-draught carburettor, filtered air enters through the side of the carburettor.

[0004] For different internal combustion engine layouts, the intake port positioning as well the carburettor type may be different thus demanding different location of air intake chamber. United States Patent No. 6910546 discloses an induction system including two different air intake chambers, each having its own filter, positioned at different locations around the engine. This design however is mainly helpful for V- type engines where there is space between the two engine cylinders and the design does not provide an air intake chamber adapted for use according to different engine layouts and different carburettors.
[0005] Hence, the present subject matter is directed to overcome all or any of the problems as set forth above and obviate the lacunae in the prior art. Therefore, it is an object of the present invention to provide an induction system configured to commonize an air intake chamber capable for use with various types of carburettors, the location of carburettors itself depending upon multiple intake port locations in various engines. It is another object of the present invention to disclose a structured and adaptable air intake chamber which is easy to assemble with multiple engine layouts thereby saving inventory cost, tooling cost and other related costs.

SUMMARY OF THE INVENTION
[0006] To this end, the present invention discloses an induction system for a straddle type vehicle comprising an air intake chamber and a carburettor; the air intake chamber operatively connected to the carburettor wherein the air intake chamber is configured to provide filtered air to the carburettor and wherein the said air intake chamber is independent of the type of carburettor used in the induction system. According to an aspect, the air intake chamber further comprises a plurality of air inlets for drawing in the atmospheric air into the air intake chamber and a plurality of air outlets for providing filtered air to the carburettor of the induction system wherein the said air inlets are disposed in an upper portion of the air intake chamber and the said air outlets are disposed in a lower portion of the air intake chamber.

[0007] The foregoing objectives and summary provide only a brief introduction to the present subject matter. To fully appreciate these and other objects of the present subject matter as well as the subject matter itself, all of which will become apparent to those skilled in the art, the ensuing detailed description of the subject matter and the claims should be read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The above and other features, aspects, and advantages of the subject matter will be better understood with regard to the following description, appended claims and accompanying drawings where:

FIG. 1 shows a straddle type vehicle in the form of a motorcycle.

FIG. 2 shows a top view of an air intake chamber according to the present invention.

FIG. 3 shows a side view of the air intake chamber according to the present invention.

FIG. 4 depicts a top view of the straddle type vehicle fitted with the air intake chamber according to an embodiment of the present invention.

FIG. 5 depicts a side view of the air intake chamber mounted on the straddle type vehicle in an embodiment of the present invention.

FIG. 6 shows the schematic diagram of the functioning of the air intake chamber as per the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0009] In order that those skilled in the art can understand the present invention, the invention is further described below so that various features of the induction system thereof proposed here are discernible from the description thereof set out hereunder. However these descriptions and the appended drawings are only used for those skilled in the art to understand the objects, features, and characteristics of the present invention and not to be used to confine the scope and spirit of the present invention. In the supporting FIGs, the same reference numerals are given to members and parts having the same functions. In the ensuing exemplary embodiments, the vehicle is a straddle ride type vehicle like a motorcycle. However, it is contemplated that the concepts of the present invention may be applied to other types of vehicles within the spirit and scope of this invention. Further "front" and "rear", and "left" and "right" referred to in the ensuing 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 vehicle. Furthermore, a longitudinal axis refers to a front to rear axis relative to the vehicle, while a lateral axis refers generally to a side to side, or left to right axis relative to the vehicle.

[00010] The present invention is now explained with the help of rendered figures. FIG. 1 shows a schematic view of a typical motorcycle 1 which comprises a body frame assembly made up of a number of tubes welded together. The motorcycle 1 has a steerable front wheel 11 and a driven rear wheel 12. The body frame primarily includes a head pipe 101, a main tube approximately horizontal to the ground and enclosed by various motorcycle components and a down tube 102. The head pipe 101 is disposed at a front end of the body frame of the motorcycle and a front fork 103 rotatably carries the front wheel 11. The front fork 103 may be connected to the head pipe 101 by any known type of suspension system. The head pipe 101 supports a steering shaft (not shown) disposed inside the head pipe 101. The upper and lower ends of the steering shaft are fixed on an upper bracket and the under bracket. The front end of the main tube and an upper end of the down tube 102 are connected to the head pipe 101. The down tube 102 extends obliquely downward in front of an internal combustion engine E from the head pipe 101 whereas the main tube extends rearward from the front end thereof.

[00011] The rear wheel 12 revolves about a central axle 13. The axle 13 is supported at each end by a swing arm 14, the swing arm in turn pivotally connected to the body frame of the motorcycle by a rear shock absorber 300. Generally a motorcycle may use any of the two arrangements for rear shock absorbers, namely dual shock and mono shock. However the present invention is exemplified through a dual shock absorber. The dual shock absorbers are fixed at their upper ends to the motorcycle frame. Their lower ends are fixed to the swing arm 14.

[00012] The anterior portion of the motorcycle placed forward to a fuel tank 105 comprises of a headlamp assembly, the headlamp assembly further comprising a headlamp 108 and a visor 107. The handle bar assembly further comprises of a handle bar extending transversely to the vehicle. The handle bar is rotatable along the longitudinal axis of the vehicle.

[00013] The engine E is disposed below the main tube, and the main tube supports it. The engine may be an engine of a water-cooled type or air-cooled type. Drive force output from the engine is transmitted to the rear wheel 12 via a transmission system. A front fender 104 is provided below the under bracket to avoid the motorcycle and its occupants from being splashed with mud. The fuel tank 105 is disposed above the main tube, on the upper side of the engine E, for storing the fuel for propelling the motorcycle 1. A seat 106 for a driver and a pillion is further provided, with the said seat being placed behind the fuel tank 105 and rearwardly of the main tube.

[00014] The induction system according to the present invention is now described. It is preferably placed below the fuel tank 105 and includes a carburettor and an air intake chamber. The air intake chamber is designed in such a way that it can be used across multiple intake port layouts in an internal combustion engine so as to save assembling time and costs.

[00015] FIG. 2 shows a top view of the said air intake chamber according to the present invention. The air intake chamber 200 is structured such that it can be commonized across the various intake port locations possible in an engine layout. It is of polygonal shape with a wider lower portion 202 and a comparatively narrower upper portion 201. The upper portion 201 is projected out of the air intake chamber 200 and rests on the lower portion 202. The air intake chamber 200 further comprises a plurality of air inlets for drawing in the atmospheric air into the air intake chamber and a plurality of air outlets for providing filtered air to the carburettor of the induction system, out of which only one is functional at a given point of time. In an embodiment of the present invention, the upper portion 201 has two openings 203, 204 laterally positioned to the air intake chamber 200. Both the said openings function as air inlet to guide the atmospheric air enter into the air intake chamber 200 and are present on either side of the longitudinal axis of the motorcycle 1.

[00016] FIG. 3 shows a side view of the air intake chamber 200 according to an embodiment of the
present subject matter. The lower portion 202 has at least two openings 205, 206 acting as air outlet to the carburettor (not shown). Generally only one opening is used and the other is closed. Thus, the said air
intake chamber 200 has at least four openings, two acting as filtered air outlet to the carburettor out of which only one is functional at a given point of time, whereas the other two openings act as air inlet bringing atmospheric air to inside the air intake chamber. The portion immediately below the upper portion of the air intake chamber 200 contains an air filter 207 employed for filtering and cleaning of the atmospheric air after it enters the air intake chamber. In an embodiment, the air filter may be a paper filter.

[00017] The atmospheric air enters into the air intake chamber 200 through either air inlet 203 or air inlet 204 or both. This air then moves toward the lower portion 202 of the air intake chamber where it passes through the air filter 207 and then moves out of any one of the air outlets. Only one of the air outlets operate at a time depending upon the intake port location and resultantly the type of carburettor used. For example, if a down-draught carburettor is used with the engine then the opening 206 is plugged using a suitable known mechanism whereas the filtered air to the carburettor is supplied through the opening 205. Likewise if a side-draught carburettor is used in the induction system, then the opening 205 is closed and filtered air is supplied to the carburettor through the opening 206 as illustrated in FIG. 6.

[00018] According to an aspect, the air intake chamber 200 is best suited for a straddle type vehicle with a perimeter type body frame F. FIG. 4 depicts a top view of the straddle type vehicle fitted with the air intake chamber 200 according to an embodiment of the present invention. The perimeter type body F frame covers the engine E from the sides connecting the head tube to the swing arm through the shortest possible inclined line structure and therefore provides suitable space for the mounting of air intake chamber 200. FIG. 5 shows the side view of the air intake chamber 200 mounted on the straddle type vehicle. The air intake chamber 200 is suitably supported below the fuel tank 105 and preferably towards the rear side of the cylinder head assembly of the engine E.

[00019] From the foregoing description, it will be appreciated that the present invention offers many advantages. The commonisation of the air intake chamber for use with different types of carburettors and intake port locations in engine layouts saves time by enabling faster vehicle development. It also saves inventory costs, tooling costs and other indirect costs. The present invention enables the inclusion of the aforementioned air intake chamber in the vehicle irrespective of the engine and carburettor used in the vehicle.

[00020] The present subject matter is thus described. The embodiments described are chosen to provide an illustration of principles of the invention and its practical application to enable thereby one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Therefore the forgoing description is to be considered exemplary, rather than limiting, and the true scope of the invention is that described in the appended claims.

We claim:

1. An induction system for a straddle type vehicle comprising an air intake chamber and a carburettor; the air intake chamber operatively connected to the carburettor and is configured to provide filtered air to the carburettor, wherein the said air intake chamber is independent of the type of carburettor used in the induction system and wherein further the straddle type vehicle has a perimeter type body frame.

2. The induction system as claimed in claim 1, wherein the air intake chamber further comprises a plurality of air inlets for drawing in the atmospheric air into the air intake chamber and a plurality of air outlets for providing filtered air to the carburettor of the induction system wherein the said air inlets are disposed in an upper portion of the air intake chamber and the air outlets are disposed in a lower portion of the air intake chamber.

3. The induction system as claimed in claim 2, wherein the air intake chamber has a narrow upper portion and a wider lower portion.

4. The induction system as claimed in claim 1, wherein only one of the said air outlets is functional with a particular type of carburettor at any given point of time and the other air outlet is closed.

5. The induction system as claimed in claim 4, wherein the other air outlet is closed through known mechanism like plugging.

6. The induction system as claimed in claim 1, wherein the said induction system used with the straddle type vehicle irrespective of the position of the intake port of the engine.