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 muffler 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.
Further, if the oxygen sensor is kept in close proximity of the engine or at a place which is covered with frame structure or any other vehicle components then temperature of oxygen sensor increases abruptly because of heat of engine and exhaust air.
Further to avoid above mentioned issue, if 02 sensor is fixed at a distance from engine near the rear end of the exhaust system, again heat requirement for the sensor is not achieved as approaching exhaust air cools down as well as engine heat does not reach to that point.
In addition to heat requirement, oxygen content in the exhaust air reduces as it flows further through the exhaust pipe. Due to this variation, constant level of oxygen content in exhaust gas cannot be achieved and hence accurate measurement cannot be taken.

Above mentioned issues affects the efficiency of the engine, thus an exhaust system is required which can address above mentioned issues of oxygen sensor mounting.
SUMMARY OF THE INVENTION
The present invention is related to an exhaust system for a motorcycle. In the claimed invention an arrangement of mounting of oxygen sensor is provided. In said arrangement oxygen sensor is mounted on the side plane of the primary chamber of the exhaust system such that oxygen sensor is passing primary chamber and sensing part of the oxygen sensor is inserted into the adaptor of the catalytic convertor.
Said exhaust system is ensuring direct exhaust air entering the primary exhaust chamber and through the catalytic convertor. Distance between the exhaust port and the primary chamber is kept at predefined value such that in the proximity of the catalytic convertor oxygen content of the exhaust air stabilises. Due to this configuration oxygen content of the exhaust air can be measured more accurately.
Further, location of the oxygen sensor facilitates direct flow of the air over the oxygen sensor ensuring proper cooling resulting high durability of said sensor. At provided location of the oxygen sensor serviceability becomes easier as chances of oxygen sensor hitting the vehicle packaging are very less.
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 arrangement of the main embodiments of the invention.
Figure 2 is depicting the embodiments and arrangement with respect to the overall vehicle packaging.
Figure 3 and Figure 4 is describing the location, enabling arrangement of the essential embodiments of the oxygen sensor.
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.

Reference is made to Figure 1 to Figure 4 in order to explain the construction and enabling arrangement of the embodiments of the claimed invention.
As shown engine 117 is inclined backwards in the motorcycle and an exhaust pipe 112 is extending rearwards such it is connecting exhaust port 119 of the engine 117 with the primary chamber 103 of the exhaust system 106. Said primary chamber 103 is further connected with the secondary chamber 104 on the rear end through a secondary pipe 105.
As shown in Figure 2, said primary chamber 103 is mounted below the swing arm 102 of the vehicle in the space between the engine 117 and the rear wheel. The oxygen sensor 108 is secured in the mounting location
109 over the primary chamber 103 and protruding outwards below the
swing arm 102.
In mentioned arrangement oxygen sensor 108 remains out from the shadow of the vehicle packaging area 101 and hence circulation of flowing air remains proper through the oxygen sensor 108. Hence the cooling of oxygen sensor 108 is enhanced due to placement of the oxygen sensor 108 at a lower level below the engine 117 where air 107 flows unhindered and is in plenty of amount. This arrangement ensures proper cooling of the oxygen sensor 108 resulting in the better durability of the oxygen sensor 108.
Referring to Figure 3, oxygen sensor 109 is mounted on the side plane
110 of the primary chamber 103 in the mounting area 109. Oxygen sensor

108 is extending of the front side of the primary chamber 103 either in inclined or straight pattern based upon the mounting or packaging requirements of the vehicle 100.
Oxygen sensor 108 is placed at the junction of exhaust pipe 112 & the primary chamber 103 such that velocity & pressure of exhaust gas 115 is relatively lesser as compared to velocity and pressure at exhaust port 119 and exhaust pipe 112 as present in existing technology.
This location of the oxygen sensor 108 improves the efficiency of the sensing part 113 and hence efficiency of the engine 117 improves as air fuel mixture entering in inlet side of the engine 117 is proper.
Further, referring to the Figure 4, oxygen sensor is inserted inside the primary chamber 103 such that sensing part 113 of the oxygen sensor 108 is secured inside the adaptor 111 of the catalytic converter 111 which further is secured inside said primary chamber 103.
Mentioned adaptor 111 is connecting the exhaust pipe 112 and catalytic converter 114 and acting like an air flow passage between the two. Exhaust air 115 from the exhaust pipe 112 is passing the adaptor in.order to reaching catalytic converter 114. Mentioned exhaust air 115 comes in direct contact with the sensing part 113 of the oxygen sensor 108 due to specific inclined cut of the exhaust pipe 112.
Inclination of the engine 117 in the backwards direction reduces the length of the exhaust pipe 112 and hence distance between the exhaust port 119 and the primary chamber 108 becomes less which helps in

keeping constant level of the oxygen residue in the exhaust air 115 till the adaptor 111 location.
Due to specific mounting surface of the oxygen sensor which is an air directing structure, exhaust gas directly reaches to the oxygen sensor. Also as the oxygen level in the exhaust gas at this location is constant, accuracy of the oxygen sensor reading increases.
Said air directing structure comprises of an inclined cut for the exhaust pipe 112 due to which exhaust air directly reaches to the oxygen sensor 108/113 oxygen content of the exhaust air 115 can be measured more accurately.
Exhaust pipe 112 is cut in an inclined angle 118 and fixed with the primary chamber 103 such that the exhaust gas 115 is always directed towards oxygen sensor 108 making it more efficient in sensing the presence of gases around it.
Further, location of the oxygen sensor 108 facilitates direct flow of the air 107 over the oxygen sensor 108 ensuring proper cooling resulting high durability of said sensor 108. Serviceability of the oxygen sensor 108 becomes easier at the provided location due to ease of removal and rearrangement of the exhaust system without harming of the oxygen sensor 108.
In addition to above mentioned benefits, claimed arrangement ensures feasibility in on board diagnostic as provided oxygen sensor 108 will act in two ways. First, said oxygen sensor 108 will work as primary oxygen

sensor 108 and provide details for oxygen amount for air fuel mixture input as well as it will provided amount of oxygen immediately before the catalytic convertor 114.
In addition to mentioned primary oxygen sensor 108 only one extra/ secondary oxygen sensor will be required after the catalytic convertor 114 to find out oxygen content after the catalytic convertor 114. Inputs from both primary and secondary oxygen sensor are used to calculate the conversion efficiency and hence working condition of the catalytic convertor 114 can be found out.

WHAT IS CLAIMED IS
1) An exhaust system for a two wheeled vehicle comprising:
an exhaust pipe fixed with an exhaust port of an engine at one end and with a primary chamber of the other end, such that distance between the exhaust port and the primary chamber is predetermined;
a secondary pipe connecting the primary chamber with a secondary chamber such that air expands inside the primary chamber and secondary chamber and exits into the atmosphere through an exit in the secondary chamber; and
an oxygen sensor mounted over a side plane of the primary chamber such that oxygen sensor is inserted inside an adaptor of a catalytic convertor secured inside the primary chamber and configured to facilitate air flow passage from the exhaust pipe to the catalytic convertor;
wherein, the primary chamber is mounted below a swing arm of the vehicle in the space between the engine and a rear wheel and said oxygen sensor is secured protruding outwards below the swing arm such that oxygen sensor remains is contact with flowing air.
2) The exhaust system as claimed in claim 1, wherein the predetermined distance is defined as a distance between the exhaust port and the primary chamber in which the residual oxygen level of exhaust gas remains constant.
3) The exhaust system as claimed in claim 1, wherein the oxygen sensor is mounted on side plane of the primary chamber such that mounting

surface is forming an air directing structure to direct exhaust air to the oxygen sensor sensing tip.
4) The exhaust system as claimed in claim 3, wherein the air directing
structure comprises a predetermined inclined cut at the end of the exhaust
5 pipe.
5) A mounting arrangement of oxygen sensor on an exhaust system in a
two wheeled vehicle, comprising:
an oxygen sensor mounted over a side plane of a primary chamber of
the exhaust system, such that oxygen sensor is inserted inside an adaptor 10 of a catalytic convertor secured inside the primary chamber and
configured to facilitate air flow passage from the exhaust pipe to the
catalytic convertor;
wherein, the primary chamber is mounted below a swing arm of the
vehicle in the space between the engine and a rear wheel and said 15 oxygen sensor is secured protruding outwards below the swing arm such
that oxygen sensor remains is contact with flowing air;
wherein, an exhaust pipe is fixed with an exhaust port of an engine at
one end and with a primary chamber of the other end, such that distance
between the exhaust port and the primary chamber is predetermined;' and
20 wherein, a secondary pipe connecting the primary chamber with a
secondary chamber such that air expands inside the primary chamber and
secondary chamber and exits into the atmosphere through an exit in the
secondary chamber.

6) The mounting arrangement of oxygen sensor as claimed in claim 5, wherein the oxygen sensor is mounted on side plane of the primary chamber such that mounting surface is forming an air directing structure to direct exhaust air to the oxygen sensor sensing tip.
5 7) The mounting arrangement of oxygen sensor as claimed in claim 6, wherein the air directing structure comprises a predetermined inclined cut at the end of the exhaust pipe.
8) The mounting arrangement of oxygen sensor as claimed in claim 1, wherein the predetermined distance is defined as a distance between the
10 exhaust port and the primary chamber in which the residual oxygen level of exhaust gas remains constant.