FIELD OF INVENTION

The present invention relates to a motorcycle and more specifically to an air filter mounting arrangement for said motorcycle.

BACKGROUND OF THE INVENTION

As is well known, the extremely compact nature of a two-wheeled vehicle gives rise to a number of design problems. Further, scooters and mopeds more particularly step through type, generally comprises a backbone type frame. The frame comprises a steering head pipe that supports a front fork. The frame also comprises a main frame member that extends rearward from the steering head pipe. The main frame member is further formed of a single tubular element.

In such vehicles, the main frame member typically forms the primary frame structure. Brackets can be provided along an intermediate portion of the main frame member and an engine can be suspended from those brackets. As can be imagined, the brackets generally protrude downward from the main frame member whereas a floorboard is secured to the upward portion of the main frame member that is often used for carrying luggage or goods.

In this type of arrangement mounting of the components of an induction system such as air cleaner, becomes difficult, owing to space limitations and further to the typical design of the frame.

In one of the prior art design the air filter is mounted below the floorboard but has limitations in accommodating the required volume of air filter any further increase in volume will impact the height of the floorboard above the ground, that results in compromise with the step through height and utility space which is undesirable, in another prior art design the air filter is mounted above the floorboard and below the seat sharing the space with the utility box. This again results in compromise with the size and space of the utility box that has its own importance thus, making it inappropriate.

SUMMARY OF THE INVENTION

Accordingly, this invention is adapted to be embodied in a step through type two wheeled vehicle having a low slug engine on a backbone type frame assembly having a main frame member extending from the head pipe, firstly, obliquely downwards, secondly, rearwards parallel to the ground defining first horizontal structure, thirdly, obliquely upwards, and finally, rearwards parallel to the ground defining second horizontal structure, said main frame member is further formed of a single tubular structure.
In an embodiment of the present invention, an air cleaner is suspended from the obliquely downwards-extending section of the main frame member whereas the engine is suspended from the first horizontal section of the body frame. This arrangement provides supply of adequate atmospheric air to the engine for its combustion without displacing the floorboard or the utility box.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a left side view of a motorcycle constructed in accordance with an embodiment of the invention.

Figure 2 is a left side view of the frame used in motorcycle of Figure 1.

Figure 3 is a prospective view of the air filter used in motorcycle of Figure 1.

DETAILED DESCRIPTION OF THE INVENTION

Referring now in detail to the drawings and initially to FIG. 1, a motorcycle constructed in accordance with an embodiment of the invention is depicted and is identified generally by the reference numeral 01. The motorcycle, as noted, has a frame assembly 02 that is comprised of a head pipe 03 and a main frame member 04 that is affixed to the head pipe 03 and extends rearward in a manner which will be described. At the rear end, a rear wheel 05 is secured to the body frame 02 through a swing arm 06 and a suspension member 07.

The head pipe 03 journals a front fork assembly 08 for steering movement about a generally vertically extending steering axis. A front wheel 09 is secured rotatably at the lower end of the front fork assembly 08 and a handlebar assembly 10 is affixed to the upper end of the front fork assembly 08 for steering of the front wheel 09 in a known manner. The front fork assembly 08 further include a suspension arrangement 11 for suspension travel of the front wheel relative to the frame assembly 02.

The main frame member 04 extends rearwards from the steering head pipe 03 firstly, obliquely downwards 04A, secondly, rearwards parallel to the ground defining first horizontal structure 04B, thirdly, obliquely upwards 04C, and finally, rearwards parallel to the ground defining second horizontal structure 04D, further said main frame member 04 is formed of a single tubular structure. A fuel tank 12 is mounted on the circumferential upper portion of the obliquely downwards-extended section 04B of the main frame member 04 and an engine 13 is suspended at an intermediate location of the first horizontal structure 04B. Above the engine 13 a floorboard 14 is secured.

A utility box 16 is provided on the circumferential upper portion of the obliquely upwards-extended section 04C of the main frame member 04. Whereas, the air filter 15 is suspended from the obliquely downwards- extended section 04B of the main frame member 04 below the fuel tank 12.

The said air filter 15 being comprised of an atmospheric air inlet 15A disposed on rear face 15C of the air filter 15 facing downwards towards the ground, so as to provide substantially unrestricted and free air flow toward the induction system, an air outlet 15B for providing clean air to the carburettor (not shown in figure) that mixes the fuel with the air, and finally the air fuel mixture is discharged to the intake ports of the engine 13, The air filter 15 also comprises of a filter element (not shown in figure) between said air inlet 15A and said air outlet 15B.

Further, as the atmospheric air inlet 15A is disposed between the air filter casing and the fuel tank 12 the entry of water and dust is minimized.

The inner face 15C of the air filter 15 has a step-structure having first and second brackets 17, 17A placed diagonally opposite to each other and protruding outwards. The depth of the step and width between the brackets 17, 17A is configured to accommodate the obliquely downwards-extended section 04B of the main frame member 04. The first bracket 17A is provided on the upper step and the second bracket 17 on the lower step.

Corresponding brackets (not shown in figure) are provided on the obliquely downwards-extended section 04B of the main frame member 04 and the air filter 15 can be bolted through the said brackets or any other appropriate means. The profile of rear face of fuel tank in an embodiment is concave to cover the downwards-extended section 04B however any appropriate shape can be used.

Further with this arrangement the floorboard 14 and utility box 16 need not be displaced upwards to accommodate the air filter 15 and substantially unrestricted and free air flow toward the induction system is provided.

It should be understood that the foregoing description is that of a preferred embodiment of the invention and that various changes and modifications may be made without departing from the spirit and scope of the invention, as defined by the appended claims.

WHAT IS CLAIMED IS:

1. A motorcycle comprising:

a) a steering head pipe;

b) a main frame member extending firstly, obliquely downwards, secondly, rearwards parallel to the ground defining first horizontal structure, thirdly, obliquely upwards, and finally, rearwards parallel to the ground defining second horizontal structure;

wherein, said main frame member is formed of a single tubular structure;

c) a fuel tank being secured to the upper circumferential portion of the downwards extending portion of said main frame member;

d) a utility box secured to the obliquely upward extending portion of said main frame member;

e) an engine being suspended from the first horizontal structure of said main frame member; and

f) an air filter to an engine is secured along the obliquely downwards extending portion of said main frame member through a plurality of bracket;

wherein, the air filter being comprised of an air inlet disposed between the air filter and the fuel tank.

2. The motorcycle, as claimed in claim 1, wherein the air filter is secured with axis parallel to the obliquely downwards extending section of the main frame member.