FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
AND
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See section 10; Rule 13)
TITLE OF THE INVENTION “AN EXHAUST SYSTEM”
APPLICANT(S)
TATA MOTORS PASSENGER VEHICLES LIMITED
Floor 3, 4, Plot-18, Nanavati Mahalaya,
Mudhana Shetty Marg, BSE,
Fort, Mumbai - 400001
Maharashtra, India
Nationality Indian.
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed.

TECHNICAL FIELD OF THE INVENTION
[0001] Present invention, in general, relates to a field of automobiles. Particularly, but not exclusively, the present invention relates to an exhaust system for an internal combustion engine. Further, embodiments of the present invention discloses at least one perforation pipe unit for the exhaust system of a vehicle.
BACKGROUND OF THE INVENTION
[0002] Conventionally, exhaust gases discharged from an internal combustion engine are directed to an exhaust pipe. The exhaust pipe conveys exhaust gases from the engine through an exhaust inlet port to other exhaust system components, such as exhaust manifold, muffler unit, etc. disposed to the exhaust pipe.
[0003] Typically, due to the flow of exhaust gas through the exhaust pipe and the exhaust system components disposed to the exhaust pipe, undesirable exhaust noise is generated in the form of a pulsating acoustic pressure waves. Generally, the exhaust noise is generated when exhaust gases carried from the engine rapidly expands at an exhaust inlet port, and thus low-frequency sound is generated when the exhaust gas flows through the exhaust pipe from the exhaust inlet port. Also, due to difference in cross-sectional areas of the exhaust pipe and the other exhaust system components, an incident wave and reflective wave are created at interactions between at least a portion of the exhaust pipe and the exhaust manifold, and between at least other portion of the exhaust pipe and the muffler unit. As a result, a cumulative of incident wave and reflective wave forms a high-amplitude and low-frequency standing/acoustic pressure wave due to constructive interference, thereby generating low-frequency noise.

[0004] In an existing exhaust system for vehicles, a plurality of resonators are disposed to the exhaust pipe in an attempt to attenuate certain resonance frequencies generated by the exhaust system. These resonators, also referred as pre-silencer units, are typically configured to break standing wave created in the exhaust system at a predetermined engine RPM. A typical resonator includes an acoustic chamber with baffles and a glass wool, and a metallic shell covering the acoustic chamber. The acoustic chamber, in particular, includes a perforated pipe with a 360 degrees of perforation phasing. The acoustic chamber of the resonator is adapted for cancelling the acoustic pressure wave of higher amplitude to create a high-frequency sound waves. Although effective, however, the addition of said plurality of resonators is expensive. Moreover, each of the plurality of resonators are often relatively large in size and this increases the overall-weight of the exhaust system on the vehicle and hence provides limited noise attenuation.
[0005] Present invention is directed to overcome one or more limitations stated above or any other limitations associated with the known arts.
SUMMARY OF THE INVENTION
[0006] One or more shortcomings of the prior art are overcome by a system as claimed and additional advantages are provided through the device and a system as claimed in the present invention. Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention.
[0007] In one non-limiting embodiment of the invention, an exhaust system for an internal combustion engine of a vehicle includes an exhaust pipe configured for carrying exhaust gases from the engine. The exhaust system further includes at least

one perforation pipe unit disposed on the exhaust pipe. The at least one perforation pipe unit includes at least one perforated pipe area integrally formed in at least a region on the exhaust pipe, and a cover member adapted for covering the at least one perforated pipe area by being secured to an outer periphery of the at least a region along at least a partial circumferential surface of the second pipe portion.
[0008] In an embodiment, the at least one perforated pipe area includes a plurality of perforation holes being integrally formed in the at least a region on the second pipe portion. Each of the plurality perforation holes comprises a predetermined diameter in a range of 1mm to 5mm.
[0009] In an embodiment, the cover member may include at least one bleeding hole of a predetermined size formed in at least a portion thereof.
[0010] In an embodiment, the plurality of perforation pipe units are disposed on the second pipe portion at a plurality of predetermined first antinode points such that each of the plurality of perforation pipe units are located at a predetermined distance from one another. Further, a predefined plurality of standing waves formed from the interactions between at least two perforation pipe units includes a plurality of maximum amplitude values that corresponds to a plurality of second antinode points.
[0011] In an embodiment, each of the plurality of perforation pipe units may be disposed along a plurality of possible percentage values of 50% to 75% of a predetermined length of the second pipe portion of the exhaust pipe.
[0012] In an embodiment of the present invention, the plurality of perforation holes are formed in a predetermined phasing in a range of 0 degree to 180 degrees along the

at least a partial circumferential surface in the at least a region of the second pipe portion.
[0013] In an embodiment, the cover member may further include at least one sound absorbing member made up of material such as glass wool.
[0014] In an embodiment, the at least one sound absorbing member conform to a predetermined profile of the cover member. The at least one sound absorbing member is detachably secured to at least an inner surface of cover member such that upon securement of the cover member to the at least one sound absorbing member, the at least one sound absorbing member is disposed between the cover member and the at least one perforated pipe area.
[0015] In an embodiment, the cover member is fixedly secured to the at least a region through welding.
[0016] In an embodiment, the cover member includes a predefined profile including at least a C-shaped profile portion and configured to conform to the at least partial circumferential surface of the exhaust pipe.
[0017] In an embodiment of the present invention, the plurality of the perforation holes are formed along a predetermined length of the exhaust pipe such that the plurality of the perforation holes are significantly aligned with an exhaust gas flow direction to vent out a predetermined exhaust gas in a predefined direction during an exhaust gas flow through the exhaust pipe.
[0018] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described

above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0019] The novel features and characteristics of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives, and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiments when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:
[0020] Figure. 1 illustrates a perspective view of an exhaust system for an internal combustion engine including a plurality of perforation pipe units, in accordance with an embodiment of the present invention.
[0021] Figure. 2 shows the exhaust system for the engine illustrating the plurality of perforation pipe inits including a cover member and at least one perforated pipe area, in accordance with an embodiment of the present invention.
[0022] Figure. 3 shows an enlarged exploded view of at least one perforation pipe unit disposed to at least a region on an exhaust pipe, in accordance with an embodiment of the present invention.
[0023] Figure. 4 shows a schematic view of the exhaust system illustrating a plurality of standing wave amplitudes including a first standing wave amplitude, a second standing wave amplitude and a third standing wave amplitude, in accordance with an embodiment of the present invention.

[0024] Figure. 5 illustrates a block diagram for the exhaust system, in accordance with an embodiment of the present invention.
[0025] The figures depict embodiments of the invention for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the system and method illustrated herein may be employed without departing from the principles of the invention described herein.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The foregoing has broadly outlined the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which forms the subject of the claims of the invention. It should be appreciated by those skilled in the art that, the conception and specific embodiments disclosed may be readily utilized as a basis for modifying other devices, systems, assemblies and mechanisms for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that, such equivalent constructions do not depart from the scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristics of the invention, to its device or system, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.
[0027] The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusions, such that a system or a device that

comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device. In other words, one or more elements in a system or apparatus proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.
[0028] Embodiments of the present invention relates to an exhaust system for an internal combustion engine. Specifically, the present invention discloses a plurality of perforations pipe units for the exhaust system of a vehicle. Conventionally, the exhaust system of the vehicle is provided with an exhaust pipe, which carries an exhaust gas flow from the internal combustion engine during the operation of the internal combustion engine.
[0029] An existing exhaust system includes a plurality of resonators, also referred as a pre-silencer unit, configured to reduce undesirable low-frequency noise generated due to constructive interference created in the form of a cumulative standing wave of incident wave and reflected wave. Typically, each of the plurality of the resonators comprises a perforated metal pipe covered by a round metallic shell. With such known structure, the typical resonator is costly, large in size and heavy in weight, and hence use of resonators to attenuate a low-frequency noise generated in the exhaust system is generally expensive, in addition, this further increases overall weight of the exhaust system.
[0030] Accordingly, the present invention relates to an exhaust system for an internal combustion engine with an improved, efficient and cost-effective mechanism of attenuating a low-frequency noise generated in the exhaust system. In an embodiment, the exhaust system includes an exhaust pipe including a first pipe portion and a second pipe portion. A catalytic converter is positioned to at least an upstream section of the

first pipe portion and a muffler unit is connected to the catalytic converter. The muffler unit is disposed to at least a downstream section of the first pipe portion. The exhaust system further includes a plurality of perforation pipe units disposed on the second pipe portion. Each of the plurality of perforation pipe units includes at least one perforated pipe area being integrally formed in at least a region on the second pipe portion, and a cover member adapted for covering the at least one perforated pipe area by being secured to an outer periphery of the at least a region along at least a partial circumferential surface of the second pipe portion.
[0031] Advantageously, as per an embodiment of the present invention, the disclosed plurality of perforation pipe units adapted for an exhaust system eliminates the requirement of utilizing a conventional large-size resonator for attenuating low-frequency acoustic noise generated in the exhaust system, and additionally provides an improved and an effective mechanism for exhaust noise reduction at significantly low-cost. Furthermore, the disclosed at least one perforated pipe area of each of the perforation pipe units are integrally formed with at least of portion of the exhaust pipe. The cover member is adapted for covering the at least one perforated pipe area. This reduces the overall number of parts in the exhaust system, and thereby facilitates in a light weight perforation pipe units to function as an effective noise attenuating unit for the exhaust system.
[0032] In an embodiment of the present invention, with the use of the disclosed perforation pipe units, the cost of the overall exhaust system is significantly reduced by approximately 15 percentage as compared with the cost of typical resonator. At the same time, a predetermined weight of the overall exhaust system is a significantly reduced weight by an approximate percentage weight value of 20 percentage less weight as compared with the weight of the typical resonator.

[0033] Furthermore, the disclosed cover member adapted to cover the at least one perforated area significantly eliminates the risk of leakage of exhaust gases above a optimum level, thereby protecting one or more elongated members such as wiring harness, brake wire, and other electronic and electrical components such as sensors packaged in the vicinity of the exhaust system from burning and damage due to high temperature exhaust gases.
[0034] Also, it is advantageous to package the plurality of perforation pipe units at a plurality of predetermined first antinode points on the second pipe portion such that each of the plurality of perforation pipe units are located at a predetermined distance from one another. With such an arrangement of the plurality of perforation pipe units, a predefined plurality of standing waves formed from the interactions between at least two perforation pipe units includes a plurality of maximum amplitude values that corresponds to a plurality of second antinode points. At the plurality of second antinode points, a predetermined acoustic pressure is high with a low- frequency. Whereas, upon formation of the predefined plurality of standing waves, the plurality of first antinode points corresponds to a plurality of node points with a minimum amplitude value, thereby generating a predefined high frequency acoustic pressure and significantly attenuating the low-frequency acoustic noise generated in the exhaust system.
[0035] Reference will now be made to the exemplary embodiments of the invention, as illustrated in the accompanying drawings. Wherever possible, same numerals have been used to refer to the same or like parts. The following paragraphs describe the present invention with reference to Figures. 1-5. It is to be noted that the exhaust system may be employed in any vehicle including but not limited to a passenger vehicle, a utility vehicle, commercial vehicles, and any other vehicle with an exhaust system.

[0036] A vehicle disclosed herein includes a prime mover such as, an IC engine, which operates by combustion of fuel. For sake of simplicity vehicle is not illustrated in the Figures.
[0037] Figure. 1 illustrates a perspective view of an exhaust system (100) for an internal combustion engine (200) (shown in Figure 2), in accordance with an embodiment of the present invention. The exhaust system (100) includes an exhaust pipe (107) being connected to the engine (200) through an exhaust inlet port (108). The exhaust pipe (107) is configured to carry exhaust gases from the engine (200) through the exhaust inlet port (108) along an exhaust flow path. The exhaust pipe (107) also includes an exhaust outlet port (109) adapted for releasing treated exhaust gas to environment. In an illustrated embodiment, the exhaust pipe (100) includes a first pipe portion (105) and a second pipe portion (106). A catalytic converter (101) is positioned to at least an upstream section (110) of the first pipe portion (105). A muffler unit (102) is connected to the catalytic converter (101). The muffler unit (102) is disposed to at least a downstream section (111) of the first pipe portion (105). The catalytic converter (101) and the muffler unit (102) are configured for treating the exhaust gases for cooling, or for removing solid constituents contained therein.
[0038] In an illustrated embodiment, a plurality of perforation pipe units (103), (104) are disposed on the second pipe portion (106). The plurality of perforation pipe units (103), (104) are located at a predetermined distance from one another.
[0039] In an illustrated embodiment, a plurality of clamping members (100a), (100b), (100c) are fixedly attached to at least a portion of the exhaust pipe (107). The plurality of clamping members (100a), (100b), (100c) are configured for detachably fastening the exhaust system (100) to a vehicle chassis (not shown).

[0040] Figure. 2 is a perspective view of the exhaust system (100) for the engine (200) illustrating the plurality of perforation pipe inits (103), (104), in accordance with an embodiment of the present invention. The plurality of perforation pipe units (103), (104) are disposed on the second pipe portion (106). In an illustrated embodiment, each of the plurality of perforation pipe units (103), (104) includes at least one perforated pipe area (201), (202) and a cover member (203), (204). In an illustrated embodiment, the at least one perforated pipe area (201), (202) is integrally formed in at least a region (205), (206) on the second pipe portion (106), and the cover member (203), (204) is adapted for covering the at least one perforated pipe area (201), (202) by being secured to an outer periphery (301) of the at least a region (205), (206) along at least a partial circumferential surface (303) of the second pipe portion (106). The at least one perforated pipe area (201), (201) includes a plurality of perforation holes (207) being integrally formed in the at least a region (205), (206) on the second pipe portion such that each of the plurality perforation holes (207) are equally spaced from each other. In an illustrated embodiment, each of the plurality perforation holes (207) comprises a predetermined diameter in a range of 1mm to 5mm.
[0041] In an illustrated embodiment, the plurality of the perforation holes (207) are formed along a predetermined length (L) of the at least a region (205), (206) of the exhaust pipe (107), such that the plurality of the perforation holes (207) are significantly aligned with an exhaust gas flow direction to vent out a predetermined exhaust gas in a predefined direction (400), (401) during an exhaust gas flow through the exhaust pipe (107). Further, in an illustrated embodiment, each of the plurality of perforation pipe units (103), (104) are disposed along a plurality of possible percentage values of 50% to 75% of a predetermined length (L’) of the second pipe portion (106) of the exhaust pipe (107).

[0042] Figure. 3 shows an enlarged exploded view of at least one perforation pipe unit (103) of the plurality of the perforation pipe units (103), (104), in accordance with an embodiment of the present invention. In an illustrated embodiment of present Figure 3, only one perforation pipe unit (103) is shown. It is to be noted that other perforation pipe units of the plurality of perforation pipe units (103), (104) has symmetrical shape, structure and configuration.
[0043] As per an illustrated embodiment, the at least one perforation pipe unit (103) is disposed on the second pipe portion (106). In an illustrated embodiment, the at least one perforation pipe unit (103) includes at least one perforated pipe area (103) and the cover member (203). In an illustrated embodiment, the cover member (203) is configured to be secured to at least a region (205) on the exhaust pipe (107) such that upon securement, a predetermined perforated pipe area (201) formed in the at least a region (205) is sufficiently covered by the cover member (103).
[0044] In an embodiment and by way of example for attenuating a high predetermined acoustic pressure, the cover member (203), (204) may further include at least one sound absorbing member (not shown) made up of material such as glass wool. More particularly, the glass-wool is configured to absorb a high frequency noise generated in the exhaust system (100). The at least one sound absorbing member is configured to conform substantially to a predetermined profile of the cover member (203), (204). The at least one sound absorbing member is detachably secured to at least an inner surface of the cover member (203), (204) such that upon securement of the cover member (203), (204) to the at least one sound absorbing member, the at least one sound absorbing member is disposed between the cover member (203), (204) and the at least one perforated pipe area (201), (202). Also, the cover member (203), (204) is fixedly secured to the at least a region (205), (206) through welding. In an illustrated

embodiment, the cover member (203), (204) is made up of materials such as stainless steel.
[0045] As per an illustrated embodiment, the plurality of perforation holes (107) are formed in a predetermined phasing of 180 degrees along the at least a partial circumferential surface (303) in the at least a region (205) of the second pipe portion (106). Further, as per an illustrated embodiment, the plurality of the perforation holes (207) are formed along a predetermined length (L) of the at least a region (205), such that the plurality of the perforation holes (207) are significantly aligned with an exhaust gas flow direction to vent out a predetermined exhaust gas in a predefined direction (400), (401) (shown in Figure 4) during an exhaust gas flow through the exhaust pipe (107).
[0046] Again referring to Figure 1, in the illustrated embodiment, the at least one perforated pipe area (201), (202) includes a plurality of perforation holes (207) being integrally formed in the at least a region (205), (206) on the second pipe portion In an illustrated embodiment, the cover member (203), (204) includes a predefined profile including at least a C-shaped profile portion (302) and configured to conform to the at least partial circumferential surface (303) of the exhaust pipe (107). This packaging of at least one perforation pipe unit (103) significantly eliminates the risk of leakage of exhaust gases above the optimum level.
[0047] It is to be noted that since the temperature of exhaust gas varies with an engine speed, load condition and capacity, thus the at least one cover member (203) is provided with one or more configuration features. A predetermined tuning of the one or more configuration features of the at least one cover member (203) significantly depends on the engine speed and capacity. That is, referring to an example, for a higher capacity engine and at a predetermined engine speed, the temperature of the exhaust

gases may reach above a predetermined temperature. In such condition, the at least one cover member (203) may include at least one bleeding hole (300) of a predetermined size formed in at least a portion thereof. The at least one bleeding hole (300) may be tuned for facilitating venting out of a predetermined amount of the exhaust gas from the predetermined perforated pipe area (201) through the at least one bleeding hole (300) to outside. Further, in some example, the one or more configuration features of the cover member (203), (204) may include the at least one bleeding hole (300) and the at least one sound absorbing member such as glass wool. In such scenario, the glass wool is configured to facilitates in substantially reducing the leakage of exhaust gases from cover member (203), (204), thereby maintaining the venting out of the exhaust gases from the exhaust pipe (107) to a predefined limit.
[0048] In another example, the one or more configuration features of the at least one cover member (203) may corresponds to elimination of the bleeding holes from the at least one cover member (203) when the temperature of the exhaust gases is below the predetermined temperature, thereby facilitating the venting out of the exhaust gas up to an optimum level. In other words, the disclosed one or more configuration features of the at least one cover member (203) facilitates the venting out of the exhaust gas to a predefined level and thereby prevents leakage of the exhaust gas to outside. This further eliminates the risk of damage of one or more electronic components in the vicinity of the exhaust system from the high temperature exhaust gas.
[0049] Figure. 4 shows a schematic view of the exhaust system (100) illustrating the plurality of perforation pipe units (103), (104) disposed on the second pipe portion (106) in accordance with an embodiment of the present invention. In an illustrated embodiment, the plurality of perforation pipe units (103), (104) are disposed at a plurality of predetermined first antinode points (A’), (B’) such that each of the plurality of perforation pipe units (103), (104) are located at a predetermined distance from one

another. With such an arrangement of the plurality of perforation pipe units (103), (104) on the second pipe portion (106), a predefined plurality of standing waves (403a), (403b), are formed from the interactions between at least two perforation pipe units (103), (104). In an illustrated embodiment, the predefined plurality of standing waves (403a), (403b), (403c) includes a plurality of maximum amplitude values that corresponds to a plurality of second antinode points (A), (B). Further, at the plurality of second antinode points (A), (B), a predetermined acoustic pressure is high with a low- frequency. Whereas, upon formation of the predefined plurality of standing waves (403a), (403b), (403c) the plurality of first antinode points (A’), (B’) corresponds to a plurality of node points with a minimum amplitude value, thereby generating a predefined high frequency acoustic pressure and significantly attenuating the low-frequency acoustic noise generated in the exhaust system (100).
[0050] In an illustrated embodiment, the plurality of perforation pipe units (103), (104) are disposed on the second pipe portion (106). In an illustrated embodiment, each of the plurality of perforation pipe units (103), (104) includes the at least one perforated pipe area (103), (104) and the cover member (203), (204). The at least one perforated pipe area (201), (202) includes a plurality of perforation holes (207) being integrally formed in the at least a region (205), (206) on the second pipe portion (106). In an illustrated embodiment, the plurality of the perforation holes (207) are formed along a predetermined length (L) of the at least a region (205), such that the plurality of the perforation holes (207) are significantly aligned with an exhaust gas flow direction to vent out a predetermined exhaust gas in a predefined direction (400), (401) (shown in Figure 4) during an exhaust gas flow through the exhaust pipe (107).
[0051] Figure. 5 illustrates a block diagram for the exhaust system (100), in accordance with an embodiment of the present invention. In an illustrated embodiment, the exhaust system (100) includes the exhaust pipe (107). The exhaust pipe (107) is

configured to carry exhaust gases from the engine (200) through the exhaust inlet port (108). In an illustrated embodiment, the plurality of perforation pipe units (103), (104) are disposed on the second pipe portion (106). The catalytic converter (101) is positioned to the at least an upstream section (110) (shown in Figure 1) of the first pipe portion (105). The muffler unit (102) is connected to the catalytic converter (101) and is disposed to at least a downstream section (111) of the first pipe portion (105). The exhaust pipe (107) also includes an exhaust outlet port (109) adapted for releasing treated exhaust gas to environment. The plurality of perforation pipe units (103), (104) are disposed on the second pipe portion (106).
[0052] Although, the above description relates to a plurality of perforation pipe units. However, the subject invention is also applicable to a single perforation pipe unit or any number of perforation pipe units being disposed on the exhaust pipe.
[0053] It should be imperative that the construction and configuration of the system and any other elements or components described in the above detailed description should not be considered as a limitation with respect to the figures. Rather, variation to such structural configuration of the elements or components should be considered within the scope of the detailed description.
Equivalents:
[0054] With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

[0055] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of
A, B, and C” would include but not be limited to systems that have A alone, B alone,
C alone, A and B together, A and C together, B and C together, and/or A, B, and C
together, etc.). In those instances where a convention analogous to “at least one of A,
B, or C, etc.” is used, in general such a construction is intended in the sense one having

skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”
[0056] In addition, where features or aspects of the invention are described in terms of Markush groups, those skilled in the art will recognize that the invention is also thereby described in terms of any individual member or subgroup of members of the Markush group.
[0057] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Referral Numerals:

Reference Number Description
100 Exhaust system
100a, 100b, 100c A plurality of clamping members
101 Catalytic converter
102 Muffler unit
103, 104 A plurality of perforation pipe units
105 A first pipe portion
106 A second pipe portion
107 Exhaust pipe
108 An exhaust inlet port
109 An exhaust outlet port
110 At least an upstream section
111 At least a downstream section
200 An internal combustion engine
201, 202 At least one perforated pipe area
203, 204 A cover member
205, 206 At least a region of the second pipe portion
207 A plurality of perforation holes
300 At least one bleeding hole
301 An outer periphery of the at least a region of the second pipe portion
302 At least a C-shaped profile portion of the cover member
303 at least a partial circumferential surface

400, 401 A predefined direction of venting out of a predetermined exhaust gas
L A predetermined length of the at least one region
L’ A predetermined length of the second pipe portion of the exhaust pipe
403a, 403b, 403c A predefined plurality of standing waves
A’, B’ A plurality of first node points
A, B A plurality of second antinode points

We Claim:
1. An exhaust system (100) for an internal combustion engine (200) of a vehicle, the
exhaust system (100) comprising:
an exhaust pipe (107) carrying exhaust gases from the engine (200); and
at least one perforation pipe unit (103) disposed on the exhaust pipe (107), the at least one perforation pipe unit (103) including at least one perforated pipe area
(203) integrally formed in at least a region (205) on the exhaust pipe (107), and a
cover member (203) adapted for covering the at least one perforated pipe area (203)
by being secured to an outer periphery (301) of the at least a region (205) along at
least a partial circumferential surface (303) of the exhaust pipe (107).
2. The exhaust system (100) as claimed in claim 1, wherein the at least one perforated pipe area (201), (202) includes a plurality of perforation holes (207) being integrally formed in the at least a region (205), (206) on the second pipe portion (106), each of the plurality perforation holes (207) comprising a predetermined diameter in a range of 1mm to 5mm.
3. The exhaust system (100) as claimed in claim 1, wherein the cover member (203),
(204) further includes at least one bleeding hole (300) of a predetermined size
formed in at least a portion thereof.
4. The exhaust system (100) as claimed in claim 1, wherein the plurality of perforation
pipe units (103), (104) are disposed on the exhaust pipe (107) at a plurality of
predetermined first antinode points (A’), (B’) such that each of the plurality of
perforation pipe units (103), (104) are located at a predetermined distance from one
another, wherein a predefined plurality of standing waves (403a), (403b), (403c)
formed from the interactions between at least two perforation pipe units (103),

(104) includes a plurality of maximum amplitude values that corresponds to a plurality of second antinode points.
5. The exhaust system (100) as claimed in claim 1, wherein each of the plurality of perforation pipe units (103), (104) is further disposed along a plurality of possible percentage values of 50% to 75% of a predetermined length (L’) of the second pipe portion (106) of the exhaust pipe (107).
6. The exhaust system (100) as claimed in claim 1, wherein the plurality of perforation holes (107) are formed in a predetermined phasing in a range of 0 degree to 180 degrees along the at least a partial circumferential surface (303) in the at least a region (205), (206) of the second pipe portion (106).
7. The exhaust system (100) as claimed in claim 1, wherein the cover member (203), (204) further includes at least one sound absorbing member made up of material such as glass wool.
8. The exhaust system (100) as claimed in claim 1, wherein the at least one sound absorbing member conform to a predetermined profile of the cover member (203), (204), wherein the at least one sound absorbing member is detachably secured to at least an inner surface of cover member (203), (204) such that upon securement of the cover member (203), (204) to the at least one sound absorbing member, the at least one sound absorbing member is disposed between the cover member (203), (204) and the at least one perforated pipe area (201), (202).
9. The exhaust system (100) as claimed in claim 1, wherein the cover member (203), (204) is fixedly secured to the at least a region (205), (206) through welding.

10. The exhaust system (100) as claimed in claim 1, wherein the cover member (203), (204) includes a predefined profile including at least a C-shaped profile portion (302) and configured to conform to the at least partial circumferential surface (303) of the exhaust pipe (107).
11. The exhaust system (100) as claimed in claim 1, wherein the plurality of the perforation holes (207) are formed along a predetermined length (L) of the at least a region (205), (206) on the exhaust pipe (107), such that the plurality of the perforation holes (207) are significantly aligned with an exhaust gas flow direction to vent out a predetermined exhaust gas in a predefined direction (400), (401) during an exhaust gas flow through the exhaust pipe (107).