FIELD OF INVENTION

The present invention generally relates to an oxygen sensor mounting structure for a motorcycle and more particularly to oxygen sensor mounting structure over exhaust system of the motorcycle.

BACKGROUND OF THE INVENTION

Generally, in motorcycles oxygen sensor is mounted either over the cylinder head or exhaust pipe. For a closed loop injection system, oxygen sensor is required to detect the amount of oxygen present in the exhaust stream based on which the amount of fuel injected for the next cycle is varied. Thus calculation of the oxygen sensor in the exhaust gas should be accurate for better efficiency of the motorcycle. Due to 02 sensor mounting structure deficiencies exhaust gas leaks from the exhaust pipe and because of that amount of actual exhaust gas varies significantly. Thus oxygen level sensed by oxygen sensor is inaccurate and hence insufficient or excess amount of fuel gets into the engine which affects the efficiency of the engine.

SUMMARY OF THE INVENTION

The present invention is related to an exhaust system for a motorcycle. This exhaust system has a double layered exhaust pipe having an inner pipe and an outer pipe fixed together maintaining a space between them. Said exhaust pipe is connecting the engine to exhaust muffler to facilitate exit of exhaust air from engine to the atmosphere. An oxygen sensor is mounted on a sensor bracket fixed in a cavity which is formed by pressing an outer pipe of the exhaust pipe such that it does not affect the diameter of an inner pipe of said exhaust pipe and space between the outer pipe and the inner pipe is filled. The sensor bracket is fixed to a mounting plate which is further fixed with the outer pipe of exhaust pipe. 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 the detailed description and accompanying claims. Scope of the invention shall be based on the claims provided.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
The present invention will become more fully understood from the detailed description given herein below and the accompanying drawing which is incorporated in and constitute embodiments of the invention, illustrate several aspects of the invention and together with a description of the embodiments serve to explain the principles of the invention and thus, are not limited of the present invention and a brief description of the drawing is as follows:

Figure 1 shows the arrangement of the exhaust muffler and oxygen sensor with respect of engine in the motorcycle.

Figure 2 and Figure 3 are providing main embodiments of the invention.

Figure 4, Figure 5, Figure 6 and Figure 7 are depicting main embodiments and enabling arrangement of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The embodiments disclosed below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings. The invention may have application to all types of vehicles. Figure 1 shows a side view of a concerned two wheeled vehicle in the form of a motorcycle capable to incorporate the present invention. The motorcycle 100 comprises a body frame assembly made up of a number of tubes welded together. The motorcycle 100 has a steerable front wheel 11 and a driven rear wheel 12. The body frame primarily includes a head pipe 1 disposed at a front end of the body frame, a main tube running across the longitudinal axis of the motorcycle 100 and enclosed by several motorcycle components, and a down tube 2. A front fork 3 may be connected to the head pipe 1 by any known type of suspension system and rotatably carries the front wheel 11. The head pipe 1 supports a steering shaft (not shown) disposed inside the head pipe 1. 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 2 are connected to the head pipe 1.

The down tube 2 extends obliquely downward in front of an engine 101 from the head pipe 1 whereas the main tube extends rearward from the front end thereof. A front fender 4 is provided below the under bracket to avoid the motorcycle and its occupants from being splashed with mud. A fuel tank 5 is disposed above the main tube for storing the fuel for propelling the motorcycle 100. A seat 6 for a driver and a pillion is further provided, with the said seat 6 being placed behind the fuel tank 5 and rearwardly of the main tube. The rear wheel 12 revolves about a sprocket splined shaft (or 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 100 by a rear suspension 10. Generally a motorcycle may use any of the two arrangements for rear suspensions, namely dual suspension and mono suspension.

The anterior portion of the motorcycle placed forward to the fuel tank 5 comprises of a headlamp assembly, the headlamp assembly further comprising a headlamp 8 and a visor 7 placed forward to a handlebar assembly. The handle bar assembly further comprises of a handle bar 9 extending transversely to the vehicle and several control switches for various motorcycle operations. The said motorcycle 100 is powered by an internal combustion engine (hereinafter "engine") 101 disposed below the main tube and supported by the down tube 2. The engine 101 may be liquid-cooled or air-cooled. Drive force output from the engine 101 is transmitted to the' rear wheel 12 through a transmission system. The transmission system includes a clutch actuated by a clutch lever placed forwardly to one side of the handle bar 9, a gear box and a chain drive. The transfer of power from the engine to the rear wheel 12 takes place generally by disengaging the clutch by pulling the clutch lever and thereafter manually shifting the gears in the gear box through a foot pedal 16 manually operated by the operator of the motorcycle M.

Referring back to Figure 1, arrangement of the exhaust system 001 and oxygen sensor 103 with respect of the engine 101 and the exhaust pipe 102 is described. Oxygen sensor 103 is mounted over the exhaust pipe 102 in a cavity 104 such that it is inserted inside the exhaust pipe 102. Further, Figure 2 and Figure 3 are depicting the arrangement of oxygen sensor 103 in the cavity 104 formed in the exhaust pipe 102 such that oxygen sensor 103 is inserted inside a sensor bracket 106. Figure 4 to Figure 7 are describing main embodiments and enabling arrangement of the invention. As shown in the figures, sensor bracket 106 is fixed in the cavity 104 formed by pressing the outer pipe 104a of the exhaust pipe 102. Said outer pipe 104a is pressed in such a way that it does not affect the diameter of the inner pipe 104b of said exhaust pipe 102. By this mechanism space 104d between the outer pipe 104a and the inner pipe 104b is filled such that exhaust gas from the inner tube 104b does not get leaked in said space 104d.

Further, a mounting plate 104c is welded with the sensor bracket 106 and the outer pipe 104c such that the sensor bracket 106 is fixed with the exhaust pipe 102. This arrangement is ensures no leakage of exhaust gas inside the space 104d that leads to more accurate measurements of oxygen sensor 103 resulting in better engine efficiency.

WHAT IS CLAIMED IS

1) An exhaust system for a motorcycle comprising an exhaust pipe connecting an engine to an exhaust muffler configured to facilitate exit of exhaust gases from engine through the exhaust muffler wherein an oxygen sensor is mounted on a sensor bracket fixed in a cavity formed by pressing an outer pipe of the exhaust pipe such that it does not affect the diameter of an inner pipe of said exhaust pipe and space between the outer pipe and the inner pipe is filled and wherein the sensor bracket is fixed to a mounting plate further fixed with the outer pipe of the exhaust pipe.

2) The exhaust system, as claimed in claim 1, wherein the mounting plate is welded with the outer pipe and the sensor bracket.

3) The exhaust system, as claimed in claim 1, wherein at least one cavity is formed over the outer pipe.