FIELD OF INVENTION
[0001] The present invention relates to an exhaust muffler and more particularly to use of dual tail pipe for efficient expulsion of exhaust gases from exhaust muffler into atmosphere.
BACKGROUND OF INVENTION
[0002] Typically, exhaust mufflers have a single tail pipe, which releases the exhaust gases to the environment with some velocity. Exhaust muffler is used to provide a passage for the burnt and unburnt gases to get expelled from the engine to the outer atmosphere. In addition, if exhaust gases are not expelled efficiently, it may lead to building up of backpressure of exhaust gases, which may lead to inefficient combustion of fuel inside the cylinder. If there are means to create negative pressure outside the muffler outlet, it will help the exhaust gases to be expelled from the muffler with lesser loss of energy eventually facilitating the efficient combustion of fuel inside the cylinder.
SUMMARY OF THE INVENTION
[0003] In the current invention, Bernoulli's principle is used to create negative exhaust gas pressure at the end of the tail so that this negative pressure can enhance the speed of exhaust gases coming out of the muffler. When the high velocity gas is flowing over a pipe's orifice, it generates a negative pressure in the pipe. The negative pressure is proportional to the gas velocity.

[0004] In the current invention, a second tail pipe is used whose inlet point is near to the baffle pipe outlet, this second tail pipe's outlet is positioned in such a way that it directs the gas flow just over the orifice of the main tail pipe also termed as tail pipe 1. This generates the negative pressure in the main tail pipe. Hence, in the current invention, baffle pipes and tail pipes are arranged in such a way to get the above results and these forms the important embodiments of the invention.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 Shows a two-wheeled vehicle with an exhaust muffler.
Figure 2 Illustrating baffle placement in the exhaust muffler.
Figure 3 Shows mechanism escaping of exhaust gas using dual tail pipes.
DETAILED DESCRIPTION OF THE INVENTION
[0005] In the current invention a plurality of baffles are placed at set intervals inside an exhaust muffler to re-route the exhaust gases between any two said baffles through passages created in the baffle. These passages inside the muffler through the baffles can be created through holes in the baffles or pipes used across the baffles and supported on the baffles. The pipes used for routing the exhaust gases through the baffles are hereby termed as baffle pipes.
[0006] The baffle pipe, withdrawing exhaust gases from the exhaust port of an engine is supported on one of the baffles such that the inlet of the baffle pipe is in the

compartment created by the said supporting baffle and the previous baffle as seen in the direction of the flow of the exhaust gases from exhaust port to the outside atmosphere and the outlet of the said baffle pipe is in the compartment created by the said supporting baffle and the next baffle.
[0007] Tail pipes are pipes mounted on the end cap of the exhaust muffler such that one end of the tail pipe is exposed to the atmosphere and another end of the tail pipe is in the chamber created by the end cap and the previous baffle. The baffle before the end cap supports a pipe for routing the exhaust gases, the said pipe termed as baffle pipe 16. In the current invention, tail pipe 1 also called as main tail pipe is supported on the exhaust muffler end cap, thus one end of tail pipe 1 is exposed to the outer atmosphere and another end of the tail pipe 1 is in the chamber created by the end cap and the previous baffle. Similarly, tail pipe 2 pipe is also supported on the exhaust muffler end cap, thus one end of tail pipe 2 is also exposed to the outer atmosphere and another end of the tail pipe 2 is in the chamber created by the end cap and the previous baffle.
[0008] Since the outlet of the said baffle pipe and inlet of the said tail pipe 1 are in the same compartment and another end of the said tail pipe 1 is exposed to the atmosphere, the exhaust gases coming out of the baffle pipe outlet is re routed through the inlet of the said tail pipe 1 and tail pipe 2. The current invention places the inlet of tail pipe 2 closer to the outlet of the baffle pipe as compared to the inlet of tail pipe 1. Thus the distance between the outlet of baffle pipe and inlet of tail pipe 2 is lesser than the distance between the outlet of tail pipe 1 and outlet of baffle pipe.

[0009] Also, the tail pipe 1 outlet end and tail pipe 2 outlet ends 24 & 25 respectively, are arranged in such a way that tail pipe 2's outlet 25, directs the gas flow just over the outlet 24 of tail pipe 1, thus generating a negative pressure at the outlet end 24 of tail pipe 1 due to the velocity of exhaust coming out of tail pipe 2. This negative pressure thus generated helps in increasing the gas flow through the tail pipe 1 and hence, decreases the backpressure inside the exhaust muffler.
[00010] As shown in Figure 1, motorcycle 31 consists of a fuel tank 32, an engine 33, an exhaust muffler 34. The fuel from the fuel tank 33 that gets inside the engine 33 undergoes combustion from which mechanical power is generated and it is transferred to the wheel 35. Since, combustion of fuel is an exothermic reaction; a large amount of heat is generated in this process.
[00011] Also as shown in Figure 1, one end of the exhaust muffler 34 is connected to the exhaust port of the engine 33. The exhaust gas passes through a catalytic convertor 36, which is placed inside the exhaust muffler 34. The carrying away of burnt and unburnt gases during combustion through the exhaust muffler, increases its temperature and consequently the exhaust muffler attains a very high temperature while the vehicle is in use.
[00012] Figure 2 illustrates an exhaust muffler with exhaust pipe 11, which carries the exhaust gas 20 coming out of the exhaust port of an engine into the catalytic converter 12. The muffler is supported on the frame of the vehicle through a means of mounting bracket 13, which is fixed, to the body muffler 14. There are baffles placed in the muffler

at various distances inside the muffler, which provide the desired paths for the flow of exhaust gases. The exhaust gases pass the baffles through pipes across these baffles called as baffle pipe 16. The muffler in the end is provided with an end cap 17. The positioning and placing of tail pipe 1 also called as main tail pipe shown as 18 in Figure 1 and tail pipe 2 shown as 19 in Figure 3 is an important embodiment of the current invention.
[00013] Figure 3 shows a section of the exhaust muffler depicting arrangements of baffle pipe and tail pipes. The current invention is related to the arrangement of baffle pipe, tail pipel and tail pipe 2 such that the exhaust gas flow path distance for tail pipe 2 shown as 22 in Figure 2 is less than the exhaust gas flow path distance for tail pipe 1 shown as 21 in Figure 2. In addition, another embodiment of the current invention is positioning of the tail pipe 2 outlet with respect to the tail pipe 1 outlet. The tail pipe 1 outlet shown as 24 is just above the tailpipe 2 outlet 25 such that when exhaust gases flow through the tail pipe 2 outlet in the direction 23 parallel to the outlet of tail pipe 1, a negative pressure is created at the outlet of tail pipel shown as 18 in Figure 2.
[00014] Application of Bernoulli's principle to create negative exhaust gas pressure at the end of the tail pipe (24) of an exhaust muffler (34) so that the generated negative pressure can enhance the speed of exhaust gases coming out of the muffler (34). When the high velocity exhaust gas (25) is made to flow over the pipe's orifice (24), it generates a negative pressure in the pipe. The negative pressure is proportional to the gas velocity. Use of two tail pipes(19, 24) one below another wherein one tail pipe (19) creates negative pressure at end of the other pipe (24) and aids in flow of exhaust gas at a greater speed.

We claim:
1. An exhaust muffler (34) for a vehicle comprising:
a baffle (15) , placed at intervals to re-route the exhaust gases between any two said baffles through atleast one passage (16) created in the baffle (15),
a baffle pipe (31), withdrawing exhaust gases from the exhaust port of an engine; the baffle pipe (31) supported on one of the baffles (15) such that the inlet of the baffle pipe is in the compartment created by the said supporting baffle and the exhaust pipe and outlet is in the compartment created by the said supporting baffle and the next baffle;
wherein baffle pipe (16) is supported on the ultimate baffle plate (15) and two tail pipes (19, 24) are supported on an end cap (17); the tail pipe (19) being shorter in length and below the tail pipe (24) in such a way that portion of exhaust gases coming out of the tail pipe (19) flows tangentially to the inlet of the tail pipe (24).
2. The exhaust muffler (34) as claimed in Claim 1 wherein tail pipe(19) is of smaller length than the said tail pipe (24).
3. The exhaust muffler (34) as claimed in Claim 1 wherein outlet profile of tail pipe (24) is parallel to direction of flow of exhaust gas from the said tail pipe (19).