Description:
FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]

EXHAUST MUFFLER OF A VEHICLE

HERO MOTOCORP LIMITED, an Indian Company at: The Grand Plaza, Plot No.2, Nelson Mandela Road, Vasant Kunj- Phase -II, New Delhi, India, 110 070

THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

FIELD OF THE INVENTION:
[001] The present invention relates to an exhaust muffler of a vehicle.

BACKGROUND OF THE INVENTION:
[002] An exhaust muffler is a device for reducing the exhaust noise of the exhaust gas emitted by the vehicle and lowers the exhaust noise by lowering the temperature and pressure of the exhaust gas. Typically, an exhaust muffler defines an interior space which is partitioned into a plurality of chambers by one or more separators in order to increase the attenuation effect.

[003] However, in certain cases, it is desired to provide an exhaust muffler for controlling a quality of the exhaust noise (which is dependent upon factors of the engine such asthe capacity of the engine, engine rotational speed, etc.). In particular, it is desired to control the quality of the exhaust noise without substantially affecting the performance of engine and the size of the exhaust muffler.

[004] Additionally, in certain instances, it is desired to provide an exhaust muffler that increases the exhaust noise to provide a distinctive sound effect (producing a booming effect). In particular, it is desired to increase the intensity of distinctive sound without affecting the performance of engine and the size of the exhaust muffler.

SUMMARY OF THE INVENTION:
[005] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key or essential features.

[006] Accordingly, the present invention provides an exhaust muffler of a vehicle, the exhaust muffler comprising: an outer wall, a first end wall, and a second end wall co-operating to define an internal space; a separator located between the first end wall and the second end wall thereby dividing the internal space into at least a first chamber, and a second chamber; an inlet pipe for introducing exhaust gas into the first chamber; an inter-chamber communication pipe penetrating through the separator for communicating a first part of the exhaust gas from the first chamber to the second chamber; and an outlet pipe for releasing exhaust gas into the atmosphere. In an embodiment of the invention, the outlet pipe comprises a first part protruding in the second chamber allowing entry of exhaust gas from the second chamber into the outlet pipe, a second part protruding in the first chamber allowing entry of exhaust gas from the first chamber into the outlet pipe, and a third part releasing the exhaust gas into the atmosphere.

[007] In an embodiment of the invention, the inlet pipe penetrates through the separator.

[008] In another embodiment of the invention, the inlet pipe has an outlet portion having a diameter “d”.

[009] In yet another embodiment of the invention, the inter-chamber communication pipe has a length in the range of “2.0*d” to “3.5*d” and a diameter in the range of “0.5*d” to “1.2*d”, the inter-chamber communication pipe comprises an inlet portion located in the first chamber and an outlet portion located in the second chamber.

[0010] In still another embodiment of the invention, the outlet portion of the inter-chamber communication pipe being at a distance in the range of “1.25*d” to “2.5*d” from the separator.

[0011] In a further embodiment of the invention, the outlet pipe has a length in the range of “3*d” to “6*d” and a diameter in the range of “0.75*d” to “1.25*d”.

[0012] In a furthermore embodiment of the invention, the first part being at a distance in the range of “0.5*d” to “1.5*d” from the separator.

[0013] In an embodiment of the invention, the second part comprises a proximal portion and a distal portion, the proximal portion being close to the separator and the distal portion being at a distance in the range of “1.5*d” to “3*d” from the outlet portion of the inlet pipe.

[0014] In another embodiment of the invention, the second part comprises plurality of holes.

[0015] In yet another embodiment of the invention, the holes have diameter in the range of “1/2*d” to “1/4*d”.

[0016] In still another embodiment of the invention, a number of holes being in the range of “0.6*d” to “0.9*d”, rounded off to nearest whole number.

[0017] In a further embodiment of the invention, a pitch of holes being in the range of “0.2*d” to “0.6*d”.

[0018] In a furthermore embodiment of the invention, the holes are disposed along a plurality of rows.

[0019] In an embodiment of the invention, the holes disposed such that an angle between the holes in two adjacent rows being in the range of 45o to 60o.

[0020] In another embodiment of the invention, an inside portion of the outer wall comprises at least one patch of acoustic material.

[0021] In yet another embodiment of the invention, the separator (108) comprises an aperture (142) for transporting a part of the exhaust gas from the first chamber (110) into the second chamber (112).

[0022] In a further aspect of the invention, there is provided a vehicle, comprising: an engine unit emitting exhaust gas; and an exhaust muffler attached to the engine and being adapted to reduce the exhaust noise of the exhaust gas. In a embodiment of the invention, the exhaust muffler comprising: an outer wall, a first end wall, and a second end wall co-operating to define an internal space; a separator located between the first end wall and the second end wall thereby dividing the internal space into at least a first chamber, and a second chamber; an inlet pipe for introducing exhaust gas into the first chamber; an inter-chamber communication pipe penetrating through the separator for communicating a first part of the exhaust gas from the first chamber to the second chamber; and an outlet pipe for releasing exhaust gas into the atmosphere. In another embodiment of the invention, the outlet pipe comprising a first part protruding in the second chamber allowing entry of exhaust gas from the second chamber into the outlet pipe, a second part protruding in the first chamber allowing entry of exhaust gas from the first chamber into the outlet pipe, and a third part releasing the exhaust gas into the atmosphere.

[0023] To further clarify the advantages and features of the invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES:
[0024] In order that the invention may be readily understood and put into practical effect, referencewill now be made to exemplary embodiments as illustrated with reference to theaccompanying drawings, where like reference numerals refer to identical or functionallysimilar elements throughout the separate views. The figures together with a detaileddescription below, are incorporated in and form part of the specification, and serve to furtherillustrate the embodiments and explain various principles and advantages, in accordance withthe present invention where:
[0025] Figure 1 illustrates a side view of an exemplary two wheeled vehicle, in accordance with an embodiment of the present invention;
[0026] Figure 2 illustrates a schematic view of an exhaust muffler constructed in accordance with a first embodiment of the invention;
[0027] Figure 3 illustrates flow of exhaust gas through the exhaust muffler shown in Figure 2 in accordance with an embodiment of the invention;
[0028] Figure 4 illustrates a schematic view of the exhaust muffler shown in Figure 2 particularly showing some of the dimensional details in accordance with an embodiment of the invention;
[0029] Figure 5 illustrates a close-up view of the second part of the outlet pipe flow of exhaust gas through the exhaust muffler shown in Figure 4 in accordance with an embodiment of the invention;
[0030] Figure 6 illustrates a schematic view of an exhaust muffler constructed in accordance with a second embodiment of the invention;
[0031] Figure 7 illustrates a schematic view of an exhaust muffler constructed in accordance with a third embodiment of the invention;
[0032] Figure 8 illustrates flow of exhaust gas through the exhaust muffler shown in Figure 6 in accordance with an embodiment of the invention; and
[0033] Figure 9 illustrates a sectional view of the exhaust muffler in accordance with a fourth embodiment of the invention.

[0034] It may be noted that to the extent possible, like reference numerals have been used torepresent like elements in the drawings. Further, skilled artisans will appreciate that elementsin the drawings are illustrated for simplicity and may not have been necessarily been drawn to scale. For example, the dimensions of some of the elements in the drawings may be exaggerated relative to other elements to help to improve understanding of aspects of the present invention. Furthermore, one or more elements may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in theart having the benefit of the description herein.

DETAILED DESCRIPTION OF THE INVENTION:
[0035] For the purpose of promoting an understanding of the principles of the invention, referencewill now be made to the embodiment illustrated in the drawings and specific language will beused to describe the same. It will nevertheless be understood that no limitation of the scope ofthe invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

[0036] It will be understood by those skilled in the art that the foregoing general description and thefollowing detailed description are explanatory of the invention and are not intended to be restrictive thereof.

[0037] As used in the description herein and throughout the claims that follow, the meaning of “a,”“an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also,as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.

[0038] Reference throughout this specification to “an aspect”, “another aspect” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrase “in an embodiment”, “in another embodiment”, and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

[0039] The terms "comprises", "comprising", or any other variations thereof, are intended to cover anon-exclusive inclusion, such that one or more devices or sub-systems or elements or structures orcomponents proceeded by "comprises... a" does not, without more constraints, preclude theexistence of other devices or other sub-systems or other elements or other structures or othercomponents or additional devices or additional sub-systems or additional elements oradditional structures or additional components.

[0040] As used herein, and unless the context dictates otherwise, the terms "coupled to", “connectedto”, “operably connected to”, and “operatively connected to” are intended to include both directconnection / coupling (in which two elements that are coupled / connected to each othercontact each other) and indirect coupling / connection (in which at least one additionalelement is located between the two elements). Therefore, the terms "coupled to" and "coupledwith" are used synonymously. Similarly, the terms “connected to” and “connected with” areused synonymously.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the samemeaning as commonly understood by one ordinary skilled in the art to which this inventionbelongs. The device, methods, and examples provided herein are illustrative only and notintended to be limiting.

[0042] The use of any and all examples, or exemplary language (e.g. “such as”) provided withrespect to certain embodiments herein is intended merely to better illuminate the inventionand does not pose a limitation on the scope of the invention. No languagein the specification should be construed as indicating any non-mentioned element as being essential tothe practice of the invention.

[0043] Groupings of alternative elements or embodiments of the invention disclosed herein are notto be construed as limitations. Each group member can be referred to and claimedindividually or in any combination with other members of the group or other elements foundherein. One or more members of a group can be included in, or deleted from, a group forreasons of convenience and/or patentability. When any such inclusion or deletion occurs, thespecification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used.

[0044] While the present invention is illustrated in the context of a vehicle, however, cover and aspects and features thereof can be used with other types of vehicles as well. The terms “vehicle”, “two wheeled vehicle” and “motorcycle” have been interchangeably used throughout the description. The term “vehicle” comprises vehicles such as motorcycles, scooters, bicycles, mopeds, scooter type vehicles, All-Terrain Vehicles (ATV) and the like.

[0045] The terms “front / forward”, “rear / rearward / back / backward”, “up / upper / top”, “down / lower / lower ward / downward, bottom”, “left / leftward”, “right / rightward” used therein represents the directions as seen from a vehicle driver sitting astride and these directions are referred by arrows Fr, Rr, U, Lr, L, R in the Figures.

[0046] Embodiments of the present invention will be described below in detail with reference to theaccompanying drawings.

[0047] Referring to Figure 1 there is illustrated a side view of a two-wheeled vehicle (10) according to an embodiment of the present invention. The vehicle (10) comprises, inter-alia, a front fork (12), a head pipe (14), a front fender (16), a front wheel (18), a headlight (20), a steering handle bar (22), a fuel tank (24), an engine unit (26), a rear wheel (28), a rear fender (30), a tail light (32), a seat (34), a tool box (36), a frame (38), and an exhaust pipe (100). It may be noted that the vehicle (10) is shown to have included above stated parts, however, those skilled in the art would appreciate that the vehicle (10) includes other parts which may not be relevant for explaining the present invention and hence are not shown and described.

[0048] Referring to Figure 2 there is illustrated a schematic view of an exhaust-pipe (100) constructed in accordance with a first embodiment of the invention. The exhaust-pipe (100) comprises a first end wall (104), a second end wall (106) and an outer wall (102), co-operating to define an internal space; a separator (108) located between the first end wall (102) and the second end wall (104) so as to divide the internal space into a first chamber (110) and a second chamber (112); an inlet pipe (114) for introducing exhaust gas into the first chamber(110); an inter-chambercommunication pipe (116) penetrating through the separator (108) for communicating a first part of the exhaust gas from the first chamber (110) to the second chamber (112); and an outlet pipe (118) for releasing exhaust gas into the atmosphere. The outlet pipe (118) comprises a first part (120) protruding in the second chamber (112) allowing entry of exhaust gas from the second chamber (112) into the outlet pipe (118), a second part (122) protruding in the first chamber (110) allowing entry of exhaust gas from the first chamber (110) into the outlet pipe (118), and a third part (124) releasing the exhaust gas into the atmosphere.

[0049] In an embodiment of the invention, the inlet pipe (114) penetrates through the separator (108). In another embodiment of the invention, the inlet pipe (114) has an outlet portion (126). In yet another embodiment of the invention, the inter-chamber communication pipe (116) comprises an inlet portion (128) located in the first chamber (110) and an outlet portion (130) located in the second chamber (110).

[0050] In still another embodiment of the invention, the second part (122) comprises a proximal portion (132) and a distal portion (134). In a further embodiment of the invention, the second part (122) comprises plurality of holes (136) disposed between the proximal portion (132) and the distal portion (134).

[0051] While the construction of the exhaust pipe in accordance with the first embodiment has been described above with reference to Figure 2, in Figure 3, the flow path taken by the exhaust gas is shown. In particular, it can be seen that the exhaust gas as produced by the engine exits from the inlet pipe (114) via the outlet portion (126) and enters the first chamber (110) as shown by first arrow (A1). The exhaust gas then takes a torturous route inside the first chamber (110) as depicted by a set of second arrows (A2) and a set of third arrows (A3). A first part of the exhaust gas is transported from the first chamber (110) into the second chamber (112). In particular a part of the exhaust gas enters the inlet portion (128) of the inter-chamber communication pipe (116) (which is located in the first chamber (110)) and exits from the outlet portion (130) of the inter-chamber communication pipe (116) (which is located in the second chamber (110)) as shown by fourth arrow (A4).

[0052] In an embodiment of the invention, the first part of the exhaust gas that exits from the outlet portion (130) of the inter-chamber communication pipe (116) then flows towards and enters into the first part (120) of the outlet pipe (118) which is located in the second chamber (112) as shown by sixth arrow (A6). It may be noted that the first part of the exhaust gas that exits from the outlet portion (130) of the inter-chamber communication pipe (116) may follow a torturous path as shown in fifth arrow (A5) prior to entering into the first part (120) of the outlet pipe (118).

[0053] While the inter-chamber communication pipe (116) only transports a first part of the exhaust gas from the first chamber (110) to the second chamber (112), a second part of the exhaust gas enters directly into the outlet pipe (118). In particular, a second part of the exhaust gas as present in the first chamber (110) after taking the torturous path shown by the third arrow (A3) directly enters into the second part (122) of the outlet pipe (118) by following the path shown by the seventh arrow (A7). This is possible for the reason that the second part (122) comprises plurality of holes (136) disposed between the proximal portion (132) and the distal portion (134).Thus, within the outlet pipe (118), the first part of the exhaust gas mixes with the second part of the exhaust gas and produces a distinct sound effect before exiting from the third part (124) of the outlet pipe (118) as shown by the eighth arrow (A8).

[0054] It has been observed that the distinct sound effect produced by the exhaust pipe can be modified by modifying the dimensions of one or more components and their inter-relationship. Thus, referring to Figure 4, dimensions of some of the components that has been observed to influence the distinct sound effect are described by way of non-limiting example. In an embodiment of the invention, the outlet portion (126) of the inlet pipe (114) is taken to have a diameter (D1) equal to “d”. It may be noted that portions of the inlet pipe (114) other than the outlet portion (114) may have diameter equal to “d” or diameter less than “d” or diameter greater than “d”.

[0055] For the sake of simplicity, the inter-chamber communicating pipe (116) is taken as a pipe having diameter (D2) (which may be uniform along its entire length) which is in the range of “0.5*d” to “1.2*d”. However, the inter-chamber communicating pipe (116) can have different diameters along its length, in which case, the portion having the minimum diameter will have a value of about “0.5*d” and the portion having the maximum diameter will have a value of about “1.2*d”. The length (L1) of the inter-chamber communicating pipe (116) would be typically in the range of “2.0*d” to “3.5*d”. In an embodiment of the outlet portion (130) of the inter-chamber communication pipe (116) being at a distance (L2) in the range of “1.25*d” to “2.5*d” from the separator (108).

[0056] In an embodiment of the invention, the outlet pipe (118) has a length (L3) in the range of “3*d” to “6*d”. For the sake of simplicity, the outlet pipe (118) is taken as a pipe having diameter (D3) (which may be uniform along its entire length) which is in the range of “0.75*d” to “1.25*d”. However, the outlet pipe (118) can have different diameters along its length, in which case, the portion having the minimum diameter will have a value of about “0.75*d” and the portion having the maximum diameter will have a value of about “1.25*d”. In an embodiment of the invention, the first part (120) of the outlet pipe (118) being at a distance (L4) in the range of “0.5*d” to “1.5*d” from the separator (108).

[0057] In an embodiment of the invention, the second part (122) comprises a proximal portion (132) and a distal portion (134), the proximal portion (132) being close to the separator (108) and the distal portion (134) being at a distance (L5) in the range of “1.5*d” to “3*d” from the outlet portion (126) of the inlet pipe (114).

[0058] Now referring to Figure 5, the second part (122) of the outlet pipe (118) comprises plurality of holes (136). In an embodiment of the invention, the holes (136) have diameter (D4) in the range of “1/2*d” to “1/4*d”. In an embodiment of the invention, a number of holes (136) present in the second part (122) of the outlet pipe (118) being in the range of “0.6*d” to “0.9*d”, rounded off to nearest whole number. In another embodiment of the invention, a pitch (L6) of holes (136) being in the range of “0.2*d” to “0.6*d”. In an embodiment of the invention, the plurality of holes (136) is disposed along a plurality of rows (138). In an embodiment of the invention, the holes (136) being disposed such that an angle (a) between the holes in two adjacent rows being in the range of 45o to 60o.

[0059] Now referring to Figure 6, there is illustrated an exhaust pipe (100) constructed in accordance with a second embodiment of the invention. The construction of the exhaust pipe (100) as per the second embodiment is substantially similar to the construction of the exhaust pipe (100) as per the first embodiment. Therefore, the difference between the construction of the exhaust pipe as per the first embodiment (shown in Figures 2 to 5 and described above) and the construction of the exhaust pipe as per the second embodiment (shown in Figure 6) will be described hereinafter in detail. In an embodiment of the invention, an inside portion of the outer wall (106) comprises at least one patch of acoustic material (140). By way of a first non-limiting example, a patch of acoustic material (140) may be provided in the first chamber (110). By way of a second non-limiting example, a patch of acoustic material (140) may be provided in the second chamber (112). By way of third non-limiting example, a first patch of acoustic material (140) may be provided in the first chamber (110) and a second patch of the acoustic material (140) may be provided in the second chamber (112). In an embodiment of the invention, at least one of a shape and a size of the first patch of acoustic material (140) may be same at least one of a shape and a size of the second patch of the acoustic material (140). In another embodiment of the invention, at least one of a shape and a size of the first patch of acoustic material (140) may be different from at least one of a shape and a size of the second patch of the acoustic material (140). In another embodiment of the invention, the acoustic material (140) covers at least 20% of a surface area of the inside portion of the outer wall (106). Particularly, the acoustic material (140) covers at least 40% of a surface area of the inside portion of the outer wall (106).By way of a non-limiting example, the acoustic material (140) is selected from a group comprising glass wool material, ceramic wool, and thermo plastic composite fiber, .

[0060] Now referring to Figure 7, there is illustrated an exhaust pipe (100) constructed in accordance with a third embodiment of the invention. The construction of the exhaust pipe (100) as per the third embodiment is substantially similar to the construction of the exhaust pipe (100) as per the first embodiment. Therefore, the difference between the construction of the exhaust pipe as per the first embodiment (shown in Figures 2 to 5 and described above) and the construction of the exhaust pipe as per the third embodiment (shown in Figure 7) will be described hereinafter in detail. It can be seen that the separator (108) provided within the exhaust pipe (100) as per the third embodiment comprises an aperture (142). In an embodiment of the invention, the aperture (142) has a diameter in a range of “0.6*d” to “0.9d”.

[0061] Now referring to Figure 8, the flow path taken by the exhaust gas is shown. It can be seen that while the exhaust gas gets split into a first part and a second part in the exhaust pipe (100) as per the first embodiment, the exhaust gas gets split into a first part, a second part and a third part in the exhaust pipe (100) as per the third embodiment.

[0062] In particular, it can be seen that the exhaust gas as produced by the engine exits from the inlet pipe (114) via the outlet portion (126) and enters the first chamber (110) as shown by first arrow (A1). The exhaust gas then takes a torturous route inside the first chamber (110) as depicted by a set of second arrows (A2) and a set of third arrows (A3). A first part of the exhaust gas is transported from the first chamber (110) into the second chamber (112) via the inter-chamber communicating pipe (116). In particular a part of the exhaust gas enters the inlet portion (128) of the inter-chamber communication pipe (116) (which is located in the first chamber (110)) and exits from the outlet portion (130) of the inter-chamber communication pipe (116) (which is located in the second chamber (112)) as shown by fourth arrow (A4). A third part of the exhaust gas is transported from the first chamber (110) into the second chamber (112) via the aperture (142) provided in the separator (108) as shown by the tenth arrow (A10) and the eleventh arrow (A11).

[0063] In an embodiment of the invention, the first part of the exhaust gas that exits from the outlet portion (130) of the inter-chamber communication pipe (116) mixes with the third part of the exhaust gas that exits from the aperture (142) provided in the separator (108). Thus, the first part of the exhaust gas mixes with the third part of the exhaust gas in the second chamber (112). The mixing of the first part of the exhaust gas with the third part of the exhaust gas leads to an increase in the exhaust noise (a booming effect).

[0064] Now the exhaust gas which is a combination of the first part and the third part flows towards and enters into the first part (120) of the outlet pipe (118) which is located in the second chamber (112) as shown by sixth arrow (A6). It may be noted that one or both of the first part of the exhaust gas that exits from the outlet portion (130) of the inter-chamber communication pipe (116)and third part of the exhaust gas that exits from the aperture (142) provided in the separator (108) may follow a torturous path as shown in fifth arrow (A5) prior to entering into the first part (120) of the outlet pipe (118).

[0065] While the inter-chamber communication pipe (116) only transports first part of the exhaust gas and third part of the exhaust gas from the first chamber (110) to the second chamber (112), a second part of the exhaust gas enters directly into the outlet pipe (118). In particular, a second part of the exhaust gas as present in the first chamber (110) after taking the torturous path shown by the third arrow (A3) directly enters into the second part (122) of the outlet pipe (118) by following the path shown by the seventh arrow (A7). This is possible for the reason that the second part (122) comprises plurality of holes (136) disposed between the proximal portion (132) and the distal portion (134). Thus, within the outlet pipe (118), the second part of the exhaust gas mixes with the mixture of first and third part of the exhaust gas and produces a distinct sound effect before exiting from the third part (124) of the outlet pipe (118) as shown by the eighth arrow (A8). In particular, due to the mixing of the second part of the exhaust gas with the mixture of first and third part of the exhaust gas produces a booming effect.

[0066] Now referring to Figure 9, which illustrates sectional view of the exhaust-pipe (100) in accordance with a fourth embodiment of the invention, it can be observed that the exhaust pipe (100) comprises a first end wall (104), a second end wall (106),and an outer wall (102) co-operating to define an internal space; a separator (108) located between the first end wall (102) and the second end wall (104) thereby dividing the internal space into at least a first chamber (110), and a second chamber (112). The exhaust pipe (100) further comprises an inlet pipe (114) for introducing exhaust gas into the first chamber (110); an inter-chamber communication pipe (116) penetrating through the separator (108) for communicating a first part of the exhaust gas from the first chamber (110) to the second chamber (112); and an outlet pipe (118) for releasing exhaust gas into the atmosphere, the outlet pipe (118) comprising a first part (120) protruding in the second chamber (112) allowing entry of exhaust gas from the second chamber (112) into the outlet pipe (118), a second part (122) protruding in the first chamber (110) allowing entry of exhaust gas from the first chamber (110) into the outlet pipe (118), and a third part (124) releasing the exhaust gas into the atmosphere.

[0067] The exhaust pipe (100) comprises a first patch of acoustic material (1401) on the inside portion of the outer wall (106) which is located within the first chamber (110) and a second patch of acoustic material (1402) on the inside portion of the outer wall (106) which is located within the first chamber (110). In the exhaust pipe as per the fourth embodiment, the separator (108) further comprises an aperture (142). Thus, it can be said that the fourth embodiment of a combination of the first embodiment, the second embodiment and the third embodiment.

[0068] Some of the advantages of the invention include a booming effect produced by the exhaust pipe. The booming effect is due to the mixing of the second part of the exhaust either solely with the first part of the exhaust gas (as per the first and second embodiments) or with a combination of the first part of exhaust gas and third part of the exhaust gas (as per the third and fourth embodiments). It has been observed that the sound effect which is produced has a balance of low and high frequency sound.

[0069] Additionally, a backpressure of the exhaust gas on the engine is reduced. Due to reduction in the backpressure applied by the exhaust gas on the engine, a performance of the engine is substantially improved. As the exhaust pipe reduces the backpressure applied by the exhaust gas on the engine, it is possible to handle higher quantity of exhaust gas produced by the engine for the same size of the exhaust pipe.

[0070] Furthermore the construction of the exhaust pipe is simple in terms a number of components and an arrangement of the components within the exhaust pipe (100). Thus, a cost of manufacturing, a time for manufacture the exhaust pipe (100) is substantially low.

[0071] While specific language has been used to describe the disclosure, any limitations arising onaccount of the same are not intended. As would be apparent to a person in the art, variousworking modifications may be made to the method in order to implement the inventiveconcept as taught herein.

[0072] The figures and the forgoing description give examples of embodiments. Those skilled in theart will appreciate that one or more of the described elements may well be combined into asingle functional element. Alternatively, certain elements may be split into multiplefunctional elements. Elements from one embodiment may be added to another embodiment.The scope of embodiments is by no means limited by these specific examples. Additionally, numerous variations, whether explicitly given in the specification or not, such as differencesin structure, dimension, and use of material, are possible.
, Claims:WE CLAIM:

1. An exhaust muffler (100) of a vehicle, the exhaust muffler (100) comprising:
a first end wall (102), a second end wall (104), and an outer wall (106) co-operating to define an internal space;
a separator (108) located between the first end wall (102) and the second end wall (104) thereby dividing the internal space into at least a first chamber (110), and a second chamber (112);
an inlet pipe (114) for introducing exhaust gas into the first chamber (110);
an inter-chamber communication pipe (116) penetrating through the separator (108) for communicating a first part of the exhaust gas from the first chamber (110) to the second chamber (112); and
an outlet pipe (118) for releasing exhaust gas into the atmosphere, the outlet pipe (118) comprising a first part (120) protruding in the second chamber (112) allowing entry of exhaust gas from the second chamber (112) into the outlet pipe (118), a second part (122) protruding in the first chamber (110) allowing entry of exhaust gas from the first chamber (110) into the outlet pipe (118), and a third part (124) releasing the exhaust gas into the atmosphere.

2. The exhaust muffler (100) as claimed in claim 1, wherein the inlet pipe (114) penetrates through the separator (108); and the inlet pipe (114) has an outlet portion (126) having a diameter (D1) equal to “d”.

3. The exhaust muffler (100) as claimed in claim 1, wherein the inter-chamber communication pipe (116) has a length (L1) in the range of “2.0*d” to “3.5*d” and a diameter (D2) in the range of “0.5*d” to “1.2*d”, the inter-chamber communication pipe (116) comprises an inlet portion (128) located in the first chamber (110) and an outlet portion (130) located in the second chamber (110); the outlet portion (130) of the inter-chamber communication pipe (116) being at a distance in the range of “1.25*d” to “2.5*d” from the separator (108).

4. The exhaust muffler (100) as claimed in claim 1, wherein the outlet pipe (118) has a length in the range of “3*d” to “6*d”; and the outlet pipe (118) has a diameter in the range of “0.75*d” to “1.25*d”.

5. The exhaust muffler (100) as claimed in claim 1, wherein the first part (120) of the outlet pipe (118) being at a distance in the range of “0.5*d” to “1.5*d” from the separator (108); and the second part (122) of the outlet pipe (118) comprises a proximal portion (132) and a distal portion (134), the proximal portion (132) being close to the separator (108) and the distal portion (134) being at a distance in the range of “1.5*d” to “3*d” from the outlet portion (126) of the inlet pipe (114).

6. The exhaust muffler (100) as claimed in claim 1, wherein the second part (122) comprises plurality of holes (136).

7. The exhaust muffler (100) as claimed in claim 6, wherein at least one of:
the holes (136) have diameter in the range of “1/2*d” to “1/4*d”;
a number of holes (136) being in the range of “0.6*d” to “0.9*d”, rounded off to nearest whole number;
a pitch of holes (136) being in the range of “0.2*d” to “0.6*d”;
the holes (136) are disposed along a plurality of rows (138); and
the holes (136) disposed such that an angle between the holes in two adjacent rows being in the range of 45o to 60o.

8. The exhaust muffler (100) as claimed in claim 1, an inside portion of the outer wall (106) comprises at least one patch of acoustic material (140).

9. The exhaust muffler (100) as claimed in claim 1, wherein the separator (108) comprises an aperture (142) for transporting a part of the exhaust gas from the first chamber (110) into the second chamber (112).

10. A vehicle (10), comprising:
an engine unit (26) emitting exhaust gas; and
an exhaust muffler (100) attached to the engine (26) and being adapted to reduce the exhaust noise of the exhaust gas; the exhaust muffler (100) comprising:
a first end wall (102), a second end wall (104) and an outer wall (106)co-operating to define an internal space;
a separator (108) located between the first end wall (102) and the second end wall (104) thereby dividing the internal space into at least a first chamber (110), and a second chamber (112);
an inlet pipe (114) for introducing exhaust gas into the first chamber (110);
an inter-chamber communication pipe (116) penetrating through the separator (108) for communicating a first part of the exhaust gas from the first chamber (110) to the second chamber (112); and
an outlet pipe (118) for releasing exhaust gas into the atmosphere, the outlet pipe (118) comprising a first part (120) protruding in the second chamber (112) allowing entry of exhaust gas from the second chamber (112) into the outlet pipe (118), a second part (122) protruding in the first chamber (110) allowing entry of exhaust gas from the first chamber (110) into the outlet pipe (118), and a third part (124) releasing the exhaust gas into the atmosphere.