EXHAUST SYSTEM FOR A TWO WHEELED VEHICLE FIELD OF INVENTION
[001] The present invention generally relates to an exhaust system for a two wheeled vehicle and more particularly to the expansion chambers of the exhaust system.
BACKGROUND OF THE INVENTION
—[002]—Generally—in- two -wheeled—vehicles, -exhaust-system-has- an expansion
chamber for the exhaust air. This expansion chamber is provided for expansion of the exhaust air up-to a certain volume such that the noise level in the exhaust system can be reduced. In most cases, volume of said expansion chamber is inversely proportional to the noise level or dB(A) level.
[003] To ensure minimum noise level in the exhaust system, volume of the expansion chamber is kept large that results in over hanging of the exhaust system. Due to overhanging on one side, centre of gravity (herein after CG) of the two wheeled vehicle as well as exhaust system shifts on heavier side. In order to maintain CG corresponding parts are to be kept on other side of the vehicle, which makes two wheeled vehicle bulky and heavy.
[004] Thus in lighter two wheeled vehicles control of noise level becomes very difficult, as to maintain CG small volume of expansion chamber is required that results in higher noise levels.
SUMMARY OF THE INVENTION
[005] Main objective of present invention is to provide an improved exhaust unit. Said exhaust unit has multiple expansion chambers such that a lower expansion chamber is mounted below the upper expansion chamber. The exhaust air coming out of the engine enters the lower chamber, flows through it and then enters the upper chamber, further expands and exits to the atmosphere. [006] Said lower expansion chamber is closed chamber and has an opening for exhaust gas intake from exhaust pipe and has a communicating passage for the upper expansion chamber. Said lower expansion chamber has atleast one compartment.
[007] For best enablement of the invention catalytic converter for the exhaust system is housed inside the lower expansion chamber and lower expansion chamber has larger volume that the upper expansion chamber. [008] Upper expansion chamber and lower expansion chamber are fixed with each other such that they lie in a same vertical plane. Rear end of lower expansion chamber and front end of upper expansion chamber are overlapping each other. [009] 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 DRAWINGS
[010] The present invention will become more fully understood from the
detailed description given herein below and the accompanying drawing(s).
Provided drawings are incorporated in and constitute embodiments of the
invention and illustrates several aspects of the invention and together with a
description of the embodiments serve to explain the principles of the invention.
Drawings given below are provided to support the description of the invention and
are not limiting the scope of the present invention. A brief description of the
drawing is as follows:
Figure 1 shows side view of a two wheeled vehicle depicting different
embodiments of the two wheeled vehicle.
Figure 2 is depicting the essential embodiments of the claimed invention.
Figure 3 is showing enabling arrangement of the claimed invention.
Figure 4 is describing the mounting location of claimed invention with respect to
other embodiments of the two wheeled vehicle.
DETAILED DESCRIPTION OF THE INVENTION
[Oil] 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 best enabling arrangements of the invention can be explained through all possible embodiments and examples of it. The invention may have application to all kind of two wheeled vehicles.
[012] Figure 1 to Figure 4, shows a side view of a concerned two wheeled
vehicle in the form of a motorcycle M capable to incorporate the present
invention. The motorcycle M comprises a body frame (not shown in Figure)
assembly made up of a number of tubes welded together. The motorcycle M has a
steerable front wheel 105 and a driven rear wheel 111. The body frame primarily
includes a head pipe disposed at a front end of the body frame, a main tube
running across the longitudinal axis of the motorcycle and enclosed by several
motorcycle components, and a down tube.
[013] A front fork 104 may be connected to the head pipe by any known type of
suspension system and rotatably carries the front wheel 105. The head pipe
supports a steering shaft 102 disposed inside the head pipe.
[014] Further, a front fender 103 is provided to avoid the motorcycle M and its
occupants from being splashed with mud. A fuel tank 119 is disposed above the
main tube for storing the fuel for propelling the motorcycle M. A seat 118 for a
driver and a pillion is further provided, with the said seat 118 being placed behind
the fuel tank 119 and rearwardly of the main tube.
[015] The rear wheel 111 revolves about a sprocket splined shaft (or central
axle). The axle is supported at each end by a swing arm 121, the swing arm 121 in
turn pivotally connected to the body frame of the motorcycle M by a rear
suspension. Generally a motorcycle M may use any of the two arrangements for
rear suspensions, namely dual suspension and mono suspension.
[016] The anterior portion of the motorcycle M placed forward to the fuel tank
119 comprises of a headlamp assembly 101, the headlamp assembly further
comprising a headlamp and a visor placed forward to a handlebar assembly 100. The handle bar assembly 100 further comprises of a handle bar extending transversely to the vehicle and several control switches for various motorcycle operations.
[017] The said motorcycle M is powered by an internal combustion engine 120 (hereinafter "engine") disposed below the main tube and supported by the down tube. The ensine mav be liauid-cooled or air-cooled. Drive force outDut from the engine 120 is transmitted to the rear wheel 111 through a transmission system. The transmission system includes a clutch actuated by a clutch lever placed forwardly to one side of the handle bar, a gear box and a chain drive 122. [018] During combustion process of said internal combustion engine 120 power is generated which is transferred to the rear wheel 111 through said transmission system 122. Combustion residue i.e. exhaust gases 123 flows out of the engine 120 and pass through an exhaust system 109 for processing and exit into the atmosphere.
[019] Referring to Figure 2 and Figure 3, exhaust unit 109 is shown in order to explain essential embodiments for the same. Said exhaust unit 109 has multiple expansion chambers such that a lower expansion chamber 110 which is mounted below the upper expansion chamber 112. The exhaust air 123 coming out of the engine 120 enters the lower expansion chamber 110, flows through it and then enters the upper chamber 112 further expands and exits into the atmosphere. [020] Said lower expansion chamber 110 is a closed chamber and has an opening 124 for exhaust gas 123 intake from exhaust pipe 106. Said lower
expansion chamber 110 has a communicating passage 128 for the upper expansion chamber 112. Said lower expansion chamber 110 has atleast one compartment 127.
[021] For best enablement of the invention, catalytic converter 125 for the exhaust unit 109 is housed inside the lower expansion chamber 110 and lower expansion chamber 110 has larger volume that the upper expansion chamber 112. Said UDDer expansion chamber 112 has an outlet 113 for exit of exhaust air 123 into the atmosphere.
[022] Said upper expansion chamber 112 and lower expansion chamber 110 are fixed with each other such that they lie in a same vertical plane. Rear end of lower expansion chamber 110 and front end of upper expansion chamber 112 are overlapping each other.
[023] Invention described above, ensures more expansion volume for reducing muffler noise dB(A) level without compromising on balancing overall CG of the motorcycle. CG of the motorcycle shifts downward and towards the front due to mounting location and structure of both expansion chambers of the motorcycle. [024] Further, as the first stage exhaust gas expansion happens in lower expansion chamber, temperature of flowing exhaust gas drops down in lower expansion chamber. Thus the exhaust air reaching the upper expansion chamber will be comparatively cooler due to which rider will observe lesser temperature. [025] Also due to larger surface area and volume of the expansion chambers temperature of the exhaust air will drop down faster.
[026] Further, since both the expansion chambers lies in the same vertical plane overhanging issue of the exhaust unit is solved and hence overall CG of the vehicle can be maintained even in lighter vehicles.
WHAT IS CLAIMED IS
An exhaust system for a two wheeled vehicle comprising a plurality of expansion chamber defining a lower expansion chamber mounted below the upper expansion chamber wherein lower chamber has an exhaust gas intake connected with exhaust pipe and a communicating passage is connecting lower expansion chamber and an upper expansion chamber.
The exhaust system, as claimed in claim 1, wherein the upper expansion chamber has at least one compartment.
The exhaust system, as claimed in claim 1, wherein the lower expansion chamber has atleast one compartment.
The exhaust system, as claimed in claim 1, wherein the lower expansion chamber has larger volume than the upper expansion chamber.
The exhaust system, as claimed in claim 1, wherein the lower expansion chamber and the upper expansion chamber are mounted in common vertical plane.
The exhaust system, as claimed in claim 1, wherein the rear end of the lower expansion chamber and front end of the upper expansion chamber overlap each other.
The exhaust system, as claimed in claim 1, wherein a catalytic converter is housed in the lower expansion chamber.