CA2730209A1 - Improved sound-attenuating muffler having reduced back pressure - Google Patents
Improved sound-attenuating muffler having reduced back pressure Download PDFInfo
- Publication number
- CA2730209A1 CA2730209A1 CA2730209A CA2730209A CA2730209A1 CA 2730209 A1 CA2730209 A1 CA 2730209A1 CA 2730209 A CA2730209 A CA 2730209A CA 2730209 A CA2730209 A CA 2730209A CA 2730209 A1 CA2730209 A1 CA 2730209A1
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- Canada
- Prior art keywords
- chamber
- muffler
- perforated pipe
- exhaust gases
- housing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
- F01N1/00—Silencing apparatus characterised by method of silencing
- F01N1/08—Silencing apparatus characterised by method of silencing by reducing exhaust energy by throttling or whirling
- F01N1/083—Silencing apparatus characterised by method of silencing by reducing exhaust energy by throttling or whirling using transversal baffles defining a tortuous path for the exhaust gases or successively throttling exhaust gas flow
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
- F01N1/00—Silencing apparatus characterised by method of silencing
- F01N1/003—Silencing apparatus characterised by method of silencing by using dead chambers communicating with exhaust gas flow passages
- F01N1/006—Silencing apparatus characterised by method of silencing by using dead chambers communicating with exhaust gas flow passages comprising at least one perforated tube extending from inlet to outlet of the silencer
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
- F01N1/00—Silencing apparatus characterised by method of silencing
- F01N1/08—Silencing apparatus characterised by method of silencing by reducing exhaust energy by throttling or whirling
- F01N1/10—Silencing apparatus characterised by method of silencing by reducing exhaust energy by throttling or whirling in combination with sound-absorbing materials
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
- F01N1/00—Silencing apparatus characterised by method of silencing
- F01N1/24—Silencing apparatus characterised by method of silencing by using sound-absorbing materials
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
- F01N2240/00—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being
- F01N2240/20—Combination or association of two or more different exhaust treating devices, or of at least one such device with an auxiliary device, not covered by indexing codes F01N2230/00 or F01N2250/00, one of the devices being a flow director or deflector
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Exhaust Silencers (AREA)
- Separating Particles In Gases By Inertia (AREA)
Abstract
The present invention relates to an improvement muffler that includes an improved inlet configuration having first and second sequential chambers with a perforated central pipe passing longitudinally through a central region of both chambers for directing the exhaust gases into the third chamber in which the deflection element is deployed. Additionally, the partition separating the first and second chamber has a hole that enables some of the gas to pass from the first chamber into the second chamber not through the central pipe.
Description
Title: Improved Sound-Attenuating Muffler Having Reduced Back Pressure FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to sound-attenuating mufflers for internal combustion engines and, more particularly, to sound-attenuating mufflers generating reduced back pressure.
Numerous muffler constructions have been proposed for the attenuation of the sound component of an exhaust gas stream from an internal combustion engine.
The present invention is an improvement to the low back-pressure sound-attenuating mufflers of U.S. Patent Nos. 6,286,623 and 6,776,257 to the present inventor and incorporated herein by reference.
The low back-pressure sound-attenuating mufflers of U.S. Patent Nos.
6,286,623 an 6,776,257 are weft suitecFfor sports cars.
There is therefore a need for a low back-pressure sound-attenuating muffler having a lower decibel output than the previous mufflers so as to be usable on regular passenger vehicles.
SUMMARY OF THE INVENTION
The present invention is a low back-pressure sound-attenuating muffler having a lower decibel output than the previous mufflers so as to be usable on regular passenger vehicles.
According to the teachings of the present invention there is provided, a muffler for an internal combustion engine comprising: (a) a housing having an inlet end with an inlet opening formed for a flow of exhaust gases into the housing and an outlet end with an outlet opening formed for a discharge of exhaust gases from the housing; (b) a first chamber and a second chamber sequentially arranged within the housing; (c) a perforated pipe passing longitudinally through a central region of both the first and the second chambers such that the perforated pipe extends partially into the first chamber, extends a full length of the second chamber;
wherein the perforations allow the exhaust gases to enter the perforated pipe so as to be directed through an interior of the perforated pipe and into the third chamber and a partition separating the first and the second chambers includes a hole that enables some of the exhaust gases to pass from the first chamber into the second chamber without passing through the central perforated pipe.
According to a further teaching of the present invention, the perforated pipe as-a-di rnet that is-W5%-f-10% o-of---tie-diar e r of he lit opening:
According to a further teaching of the present invention, an upstream end of the perforated pipe is partially sealed.
According to a further teaching of the present invention, an upstream end of the perforated pipe is 60%-80% open.
According to a further teaching of the present invention, perforations in the perforated pipe extending partially into the first chamber cover 25%-35% of the surface of the perforated pipe and, perforations in the perforated pipe extending the full length of the second chamber cover 60%-75% of the surface of the perforated pipe.
According to a further teaching of the present invention, there is also provided: (d) a third chamber containing a deflection element, the perforated pipe extending so as to open at its downstream end into a third chamber, thereby directing the exhaust gases toward the deflection element; and (e) a fourth chamber configured to channel the flow of gas to the outlet opening.
According to a further teaching of the present invention, the deflection element is a hollow pyramid having interior surfaces and exterior surfaces joining at a first end to form a pyramidal apex, the pyramidal apex pointing toward the inlet end of the muffler and extending at a second end to form an open base interconnected to a partition separating the third and the fourth cambers.
According to a further teaching of the present invention, the deflection element is a dome-shaped partition having an exterior surface, a first end of the - ex-tenor-sur-face-pointing ow-ar-d the inle-t-end-0f the-muff r; m&-widening-out-at-a-second end to form a base interconnected to a partition separating the third and the fourth cambers.
There is also provided according to the teachings of the present invention, a muffler for an internal combustion engine comprising: (a) a housing having an inlet end with an inlet opening formed for a flow of exhaust gases into the housing and an outlet end with an outlet opening formed for a discharge of exhaust gases from the housing; (b) at least a first chamber, an intermediate and a last chamber sequentially arranged within the housing, the intermediate chamber containing a deflection element chosen from a group including: (i) a hollow pyramid; and (ii) a dome-shaped partition; (c) a pipe passing longitudinally through the first chamber so as to open at its downstream end into the intermediate chamber, thereby directing the exhaust gases toward the deflection element; and (d) a perforated pipe extending through the last chamber, the perforated pipe having an upstream opening into the intermediate chamber and configured to channel the exhaust gas to the outlet opening.
According to a further teaching of the present invention, the pipe passes longitudinally through an axially central region of the first chamber.
According to a further teaching of the present invention, a partition separating the first and the intermediate chambers includes a hole that enables some of the exhaust gases to pass freely between the first chamber and the intermediate chamber.
According to a further teaching of the present invention, the first chamber 5- e-xtends-be-;w-ee-n-4-0%-85%-of-the total4eng -oftbe-housing:
According to a further teaching of the present invention, the last chamber extends between 5%-80% of the total length of the housing.
According to a further teaching of the present invention, there is also provided a sound-attenuating material deployed in at least one of the first chamber, the intermediate chamber and the last chamber.
According to a further teaching of the present invention, the sound-attenuating material is configured from at least one chosen from the group that includes mineral fibers and synthetic fibers.
The present invention relates to sound-attenuating mufflers for internal combustion engines and, more particularly, to sound-attenuating mufflers generating reduced back pressure.
Numerous muffler constructions have been proposed for the attenuation of the sound component of an exhaust gas stream from an internal combustion engine.
The present invention is an improvement to the low back-pressure sound-attenuating mufflers of U.S. Patent Nos. 6,286,623 and 6,776,257 to the present inventor and incorporated herein by reference.
The low back-pressure sound-attenuating mufflers of U.S. Patent Nos.
6,286,623 an 6,776,257 are weft suitecFfor sports cars.
There is therefore a need for a low back-pressure sound-attenuating muffler having a lower decibel output than the previous mufflers so as to be usable on regular passenger vehicles.
SUMMARY OF THE INVENTION
The present invention is a low back-pressure sound-attenuating muffler having a lower decibel output than the previous mufflers so as to be usable on regular passenger vehicles.
According to the teachings of the present invention there is provided, a muffler for an internal combustion engine comprising: (a) a housing having an inlet end with an inlet opening formed for a flow of exhaust gases into the housing and an outlet end with an outlet opening formed for a discharge of exhaust gases from the housing; (b) a first chamber and a second chamber sequentially arranged within the housing; (c) a perforated pipe passing longitudinally through a central region of both the first and the second chambers such that the perforated pipe extends partially into the first chamber, extends a full length of the second chamber;
wherein the perforations allow the exhaust gases to enter the perforated pipe so as to be directed through an interior of the perforated pipe and into the third chamber and a partition separating the first and the second chambers includes a hole that enables some of the exhaust gases to pass from the first chamber into the second chamber without passing through the central perforated pipe.
According to a further teaching of the present invention, the perforated pipe as-a-di rnet that is-W5%-f-10% o-of---tie-diar e r of he lit opening:
According to a further teaching of the present invention, an upstream end of the perforated pipe is partially sealed.
According to a further teaching of the present invention, an upstream end of the perforated pipe is 60%-80% open.
According to a further teaching of the present invention, perforations in the perforated pipe extending partially into the first chamber cover 25%-35% of the surface of the perforated pipe and, perforations in the perforated pipe extending the full length of the second chamber cover 60%-75% of the surface of the perforated pipe.
According to a further teaching of the present invention, there is also provided: (d) a third chamber containing a deflection element, the perforated pipe extending so as to open at its downstream end into a third chamber, thereby directing the exhaust gases toward the deflection element; and (e) a fourth chamber configured to channel the flow of gas to the outlet opening.
According to a further teaching of the present invention, the deflection element is a hollow pyramid having interior surfaces and exterior surfaces joining at a first end to form a pyramidal apex, the pyramidal apex pointing toward the inlet end of the muffler and extending at a second end to form an open base interconnected to a partition separating the third and the fourth cambers.
According to a further teaching of the present invention, the deflection element is a dome-shaped partition having an exterior surface, a first end of the - ex-tenor-sur-face-pointing ow-ar-d the inle-t-end-0f the-muff r; m&-widening-out-at-a-second end to form a base interconnected to a partition separating the third and the fourth cambers.
There is also provided according to the teachings of the present invention, a muffler for an internal combustion engine comprising: (a) a housing having an inlet end with an inlet opening formed for a flow of exhaust gases into the housing and an outlet end with an outlet opening formed for a discharge of exhaust gases from the housing; (b) at least a first chamber, an intermediate and a last chamber sequentially arranged within the housing, the intermediate chamber containing a deflection element chosen from a group including: (i) a hollow pyramid; and (ii) a dome-shaped partition; (c) a pipe passing longitudinally through the first chamber so as to open at its downstream end into the intermediate chamber, thereby directing the exhaust gases toward the deflection element; and (d) a perforated pipe extending through the last chamber, the perforated pipe having an upstream opening into the intermediate chamber and configured to channel the exhaust gas to the outlet opening.
According to a further teaching of the present invention, the pipe passes longitudinally through an axially central region of the first chamber.
According to a further teaching of the present invention, a partition separating the first and the intermediate chambers includes a hole that enables some of the exhaust gases to pass freely between the first chamber and the intermediate chamber.
According to a further teaching of the present invention, the first chamber 5- e-xtends-be-;w-ee-n-4-0%-85%-of-the total4eng -oftbe-housing:
According to a further teaching of the present invention, the last chamber extends between 5%-80% of the total length of the housing.
According to a further teaching of the present invention, there is also provided a sound-attenuating material deployed in at least one of the first chamber, the intermediate chamber and the last chamber.
According to a further teaching of the present invention, the sound-attenuating material is configured from at least one chosen from the group that includes mineral fibers and synthetic fibers.
According to a further teaching of the present invention, the hollow pyramid deflection element has interior surfaces and exterior surfaces joining at a first end to form a pyramidal apex, the pyramidal apex pointing toward the inlet end of the muffler and extending at a second end to form an open base interconnected to a partition separating the intermediate and the last cambers.
According to a further teaching of the present invention, the dome-shaped partition deflection element has an exterior surface, a first end of the exterior surface pointing toward the inlet end of the muffler, and widening out at a second end to form an open base interconnected to a partition separating the intermediate and the third cambers.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:
SIG-l-is-a-p-exspectie c-ut_o4)en-vievL-o tl e rr ffler o U.S Patent: No.
6,286,623;
FIG. 2 is a perspective, cut-open view of the muffler of U.S. Patent No.
6,776,257;
FIG. 3 is a perspective, cut-open view of a first preferred embodiment of a muffler constructed and operational according to the teachings of the present invention;
FIG. 4 is a perspective, cut-open view showing the flow path of exhaust gases through the embodiment of FIG. 3;
According to a further teaching of the present invention, the dome-shaped partition deflection element has an exterior surface, a first end of the exterior surface pointing toward the inlet end of the muffler, and widening out at a second end to form an open base interconnected to a partition separating the intermediate and the third cambers.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:
SIG-l-is-a-p-exspectie c-ut_o4)en-vievL-o tl e rr ffler o U.S Patent: No.
6,286,623;
FIG. 2 is a perspective, cut-open view of the muffler of U.S. Patent No.
6,776,257;
FIG. 3 is a perspective, cut-open view of a first preferred embodiment of a muffler constructed and operational according to the teachings of the present invention;
FIG. 4 is a perspective, cut-open view showing the flow path of exhaust gases through the embodiment of FIG. 3;
FIG. 5 is a perspective, cut-open view of a second preferred embodiment of a muffler constructed and operational according to the teachings of the present invention;
FIG. 6 is a perspective, cut-open view showing the flow path of exhaust gases through the embodiment of FIG. 5;
FIG. 7 is a perspective, cut open view of a third preferred embodiment of a muffler constructed and operational according to the teachings of the present invention having a pyramidal deflection element; and FIG. 8 is a perspective, cut-open view of a fourth preferred embodiment of a muffler constructed and operational according to the teachings of the present invention having a dome-shaped deflection element.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is a low back-pressure sound-attenuating muffler having-a-Io er__decib~l~utput~har~the pze~io a ffexs o as t4 be usable on regular passenger vehicles.
The principles and operation of low back-pressure sound-attenuating muffler according to the present invention may be better understood with reference to the drawings and the accompanying description.
By way of introduction reference is made to the prior art low back-pressure sound-attenuating mufflers of V.S. Patent Nos. 6,286,623 and 6,776,257 to the present inventor and incorporated herein by reference.
it should be noted that as used herein, references to sequence such as first, intermediate and last refer to the relationship of elements in the drawings and are not intended to limit the scope of the present invention.
Figure 1 shows a cut open view of the muffler 200 of U.S. Patent No.
6,286,623. The muffler 200 consists of an elongated housing 202 having an inlet 206 for introducing the exhaust gases, an outlet 208 for discharging the exhaust gases, a pyramidal partition 250 and converging partitions 240 and 260.
The exhaust gases from the internal combustion engine are introduced into the muffler 200 through the inlet 206. The exhaust gases enter the housing 202 and flow longitudinally through the length of muffler 200 passing first through chamber 212. The exhaust gases exit chamber 212 through an opening in partition 240.
Partition 240 is shaped like a funnel (or truncated pyramid), disposed such that the opening in the partition 240 centers the flow of exhaust gases within housing 202.
The flow exhaust gases then enters the second chamber 214 and encounters the apex 1-5 230-of-pyrarni-dal partition Z-5O; causing-t-he-Howto-lie-dofleeted-alo g he xt iDr faces of pyramidal partition 250 and towards the interior surface of the outer wall of housing 202.
The exhaust gases flow through the four spaces 252 formed by the rugose base of the pyramidal partition 250. A substantial first portion of the exhaust gases continue to flow in the direction of the outlet pipe 208, thereby creating a low pressure region inside the pyramidal partition 250. Consequently, a second portion of the exhaust gases changes direction and enters (is drawn into) the inside region of pyramidal partition 250 before continuing toward the outlet pipe 208. The exhaust gases flow through converging partition 260, which is substantially identical in shape and in disposition to converging partition 240. Thus, the flow of exhaust gases enters the third chamber 216 and is again centered within the housing 202 by the partition outlet 224 before being discharged through outlet pipe 208.
Figure 2 shows a perspective, cut-open view of the muffler 300 of U.S.
Patent No. 6,776,257. Muffler 300 includes an elongated housing 302 having an inlet 306 for introducing the exhaust gases, an outlet 308 for discharging the exhaust gases, a main partition 350, and an aligning partition 340.
The exhaust gases from the internal combustion engine are introduced through the inlet 306. The exhaust gases enter housing 302 and flow longitudinally through the length of muffler 300 passing first through chamber 312. The exhaust gases exit chamber 312 through an opening in partition 340. Partition 340 is preferably shaped like a funnel (or truncated pyramid), and most importantly, is disposed such that the exhaust gas flow is centered within the housing 302 as the ex-haunt aces-enter th,e~--see-ond-chamber 314-and-floe-how of--exact-gases-encounters the top of domed partition 350, causing the flow to be deflected along the exterior face of domed partition 350.
The exhaust gases flow through openings 352 in the sides of domed partition 350 Openings 352 are preferably disposed on opposite sides of domed partition 350.
Subsequently, the exhaust gases continue to flow in the direction of outlet pipe 308, thereby creating a low pressure region inside domed partition 350.
Consequently, a portion of the exhaust gases change direction and enter (are drawn into) the inside of domed partition 350 before continuing in the direction of outlet pipe 308. The exhaust gases flow through converging partition 360, which is advantageously similar in shape and in disposition to converging partition 340, and enter the third chamber 316 before being discharged through outlet pipe 308.
Generally speaking, the embodiments of U.S. Patent Nos. 6,286,623 and 6,776,257 as briefly described above include an inlet chamber, a deflection chamber in which a deflection element is deployed and an outlet chamber.
The first to preferred embodiments of the present invention relate to an improvement that may be used to benefit both of the previous muffler embodiments described above. Specifically, the present invention includes an improved inlet configuration having first and second sequential chambers with a perforated central pipe passing longitudinally through a central region of both chambers for directing the exhaust gases into the third chamber in which the deflection element is deployed. Additionally, the partition separating the first and second chamber has a hole that enables some of the gas to pass from the first chamber into the second 5 chamber et thr-ough-theme-entr-al-pipe.
Described below are two exemplary embodiments of the present invention The first preferred embodiment of Figures 3 and 4 relates to a muffler combining the features of the present invention with the pyramidal partition deflection element of U.S. Patent No. 6,286,623. The second preferred embodiment of Figures 5 and relates to a muffler combining the features of the present invention with the domed partition deflection element of U.S. Patent No. 6,776,257 Referring now to the drawings, Figures 3 and 4 illustrate a muffler 2 generally defined by a housing 4. An inlet 6 is provided in the inlet end of the muffler for introducing exhaust gases into the first chamber 10. The improved inlet configuration has the first chamber 10 and a second chamber 12 sequentially arranged within muffler 2. A perforated pipe 20, with its upstream end 22 partially sealed, passing longitudinally through a central region of both the first 10 and the second 12 chambers such that perforated pipe 20 extends partially into the first chamber 10 and extends the full length of the second chamber 12. Perforated pipe 20 extends at its downstream end 24 through partition 40 and opens into the third chamber 14. The perforations 26a allow the exhaust gases to enter the perforated pipe 20 from the first chamber 10, while perforations 26b allow the exhaust gases to enter the perforated pipe 20 from the second chamber 12. Once the exhaust gases enter perforated pipe 20 they are directed through the interior of perforated pipe 20 and into the third chamber 14. As illustrated here, the perforations 26 are formed over a predetermined percentage of the surface of pipe 20.
The partition 30 separating the first and second chambers includes a I -preferably round-hole-3-2 that-enables-semo--ef-the-gas-to pass-rem-thefirst-chambe 10 into the second chamber 12 without passing through the central perforated pipe 20. Exhaust gases that enter the second chamber 12 then pass through the perforations 26 in the section of perforated pipe 20 deployed in second chamber 12.
It will be appreciated that hole 32 may be of substantially any suitable size and shape.
With this basic understanding of the general structure of the first two chambers of the muffler, it will be appreciated that inlet 6 is configured for attachment to the exhaust pipe of the vehicle on which the muffler is deployed and therefore may vary in diameter depending on the specifications of the of the vehicle manufacturer. It will be appreciated that inlet 6 may be configured as more that one inlet pipe. It will be readily understood that in such an embodiment, the percentages listed herebelow are applied to the combined size of all inlet pipes.
Similarly, the outlet pipe 8 may be configured as more that one outlet pipe and the percentages listed herebelow are applied to the combined size of all outlet pipes.
In order for the muffler of the present invention to perform at an optimum level, perforated pipe 20 has a diameter that is 100%-130% of the diameter of inlet pipe 6. It will be appreciated that perforated pipe 20 may be implemented as more than one perforated pipe as long as the ratio of 100%-130% of the diameter of inlet pipe 6 is maintained. The upstream end 22 of the perforated pipe 20 is partially sealed so as to be 60%-80% open. The perforation holes in the perforated pipe may range from 15mm-S5mm in diameter. Perforations 26a cover between 20%-40% of the surface of perforated pipe 20, while perforations 26b cover 50%-90%
of i 5--tZe-&urface of perforated pipe 20.- 4ole 2-configured-in partit:ion-30-has a-dia ter that is 60%-80% of the diameter of perforated pipe 20. It will be appreciated that hole 32 may be implemented as a plurality of holes configured in partition 30, however, the combined size of the opening still falls within the range of 60%-80%
of the diameter of perforated pipe 20. Further, embodiments in which the second chamber 12 is subdivided into a number of chambers through which perforated pipe 20 passes are within the scope of the present invention. It should be noted that these specifications apply to the embodiment of the present invention described bellow with regard to Figures 5 and 6, as well as any muffler constructed and operational according to the teachings of the present invention.
Similar to the muffler of Figure 1, the flow of exhaust gases is centered within the housing 4 as the exhaust gases leaves the downstream end 24 of the perforated pipe 20, enters the third chamber 14. The flow of exhaust gases encounters the apex of pyramidal partition 50, which is spaced a distance of 20mm 60mm from the downstream end 24 of the perforated pipe 20, causing the flow to be deflected along the exterior faces of pyramidal partition 50 and towards the interior surface of the outer wall of housing 4.
The exhaust gases flow then through the four spaces 52 formed by the rugose base of the pyramidal partition 50. A substantial first portion of the exhaust gases continue to flow in the direction of the outlet pipe 120, thereby creating a low pressure region inside the pyramidal partition 150. Consequently, a second portion of the exhaust gases changes direction and enters (is drawn into) the inside region of pyramidal-partition a0-befor"ont-inuing~-ow,ard-the-outlet-pipe 8 Thhee aus gases-flow through partition 60 and is again centered within the housing 100 as the exhaust gases enter the fourth chamber 16 before being discharged through outlet pipe 8, formed in the outlet end of the muffler.
The arrows in Figure 4 illustrate the flow path of the exhaust gases through this embodiment of the muffler of the present invention.
Figures 5 and 6 illustrate a muffler 102 generally defined by a housing 4, which includes an inlet configuration similar to the embodiment of Figures 3 and 4, therefore, the same reference numerals are used here to refer to corresponding components. It will be appreciated that the specifications relating to component size detailed above apply equally here as well.
An inlet 6 is provided in the inlet end of the muffler for introducing exhaust gases into the first chamber 10. The improved inlet configuration of this embodiment also has the first chamber 10 and a second chamber 12 sequentially arranged within muffler 102. A perforated pipe 20, with its upstream end 22 sealed, passing longitudinally through a central region of both the first 10 and the second 12 chambers such that perforated pipe 20 extends partially into the first chamber 10 and extends the full length of the second chamber 12. Perforated pipe 20 extends at its downstream end 24 through partition 40 and opens into the third chamber 14.
The perforations 26 allow the exhaust gases to enter the perforated pipe 20 so as to be directed through the interior of perforated pipe 20 and into the third chamber 14.
The partition 30 separating the first and second chambers includes a preferably round hole 32 that enables some of the gas to pass from the first chamber 1 5-10-into the-se wnd-chamber T-2-ithout p- as ing-through-the-centr-al-per-for-atzdpipe-20. Exhaust gases that enter the second chamber 12 then pass through the perforations 26 in the section of perforated pipe 20 deployed in second chamber 12.
It will be appreciated that in this embodiment as well, hole 32 may be of substantially any suitable size and shape.
Similar to the muffler of Figure 2, the exhaust gas flow is centered within the housing 4 as the exhaust gases leaves the downstream end 24 of the perforated pipe 20, and enters the third chamber 14 and the flow of exhaust gases encounters the top of domed partition 150, causing the flow of exhaust gases to be deflected along the exterior face of domed partition 150. Dome-shaped partition 150 having an exterior surface, a first end of the exterior surface points toward the inlet end of the muffler, and widening out at a second end to form a base, said dome-shaped partition having at least two partition openings disposed between said first end and said second end of said exterior surface The exhaust gases flow through openings 152 in the sides of domed partition 150. Openings 152 are preferably disposed on opposite sides of domed partition 150.
Subsequently, the exhaust gases continue to flow in the direction of outlet pipe 8 formed in the outlet end of the muffler, thereby creating a low pressure region inside domed partition 150. Consequently, a portion of the exhaust gases change direction and enter (are drawn into) the inside of domed partition 150 before continuing in the direction of outlet pipe 8. The exhaust gases flow through an opening (not shown) partition 160, and enter the fourth chamber 16 before being -15 disc-harmed--thr-ough-outlet-pipe-S:
The arrows in Figure 6 illustrate the flow path of the exhaust gases through this embodiment of the muffler of the present invention.
The embodiment of Figure 7 relates to a third preferred embodiment 400 of the muffler combining features of the present invention with the pyramidal partition deflection element of U.S. Patent No. 6,286,623.
Figure 7 illustrates muffler 400 of the present invention generally defined by a housing 401 and end walls 402 and 406. An inlet 408 for introducing exhaust gases into the muffler 400 is provided in end wall 402. The inlet configuration. of the mufflers of the present invention includes an inlet pipe 409 that is axially centered within the housing 401 and extends from the inlet 408 through the first chamber 403 and opens at its downstream end into the intermediate chamber 417 sequentially arranged within muffler 400.
As the flow of exhaust gases leaves the downstream end of pipe 409 and enters the intermediate chamber 417, the flow of exhaust gases encounters the apex of pyramidal deflection element 410 causing the flow to be deflected along the exterior faces of pyramidal deflection element 410 and towards the interior surface of the outer wall of housing 401. It will be appreciated that although pipe 409 and the apex of pyramidal deflection element 410 are illustrated herein as substantially axially centered within the housing 401, it is within the scope of the present invention to provide a non-straight pipe that extends from an inlet that is not axially centered within the housing 401 to a downstream end that is aligned with the apex of pyramidal deflection element 410, which need not be axially centered within the Sousing-404:
Opening 413 configured in interior partition wall 404 allows exhaust gasses to enter the first chamber 403 and thereby alleviate some excess pressure that may from in the intermediate chamber 417. It will be appreciated that interior partition wall 404 may be configured with a single opening 413 as illustrated herein, or with a plurality of opening to allow passage of exhaust gasses between the first 403 and intermediate 417 chambers.
The exhaust gases then flow through the four spaces 418 formed at the base of the pyramidal deflection element 410. A substantial first portion of the exhaust gases continue to flow in the direction of the opening 414 to the perforated pipe 411, thereby creating a low pressure region inside the pyramidal deflection element 410. Consequently, a second portion of the exhaust gases changes direction and enters (is drawn into) the inside region of pyramidal deflection element 410 before continuing toward opening 414. The flow pattern thus created serves to decrease the sounds associated with the exhaust.
Perforated pipe 411 extends from opening 414 through the last chamber 407 to the outlet pipe 412. As the exhaust gases flow through perforated pipe 411, the associated sound waves pass freely through the perforations 416 into the last chamber 407 and are thereby further dissipated. Preferably, as illustrated herein, the last chamber 407 contains a sound-attenuating material made from mineral fibers or synthetic fibers either individually or in combination. Such fibers include, but are not limited to, Asbestos fibers, basalt fibers, mineral wool, glass wool, metal wools such as steel wool and bronze wool, carbon fiber and aramid fiber such as Kevlaro.
-1-5 T-he-embodiment-of figure- Vr-efates-t~~s cond-pr-e-fe dembodlment-50Q
of the muffler combining the features of the present invention with the dome-shaped deflection element of U.S. Patent No. 6,776,257. Muffler 500 is generally defined by a housing 501 and end walls 502 and 506. An inlet 508 for introducing exhaust gases into the muffler 500 is provided in end wall 502. The inlet configuration of the mufflers of the present invention includes an inlet pipe 509 that is axially centered within the housing 501 and extends from the inlet 508 through the first chamber 503 and opens at its downstream end into the intermediate chamber 517 sequentially arranged within muffler 500.
As the flow of exhaust gases leaves the downstream end of pipe 509 and enters the intermediate chamber 517, the flow of exhaust gases encounters the top of the dome-shaped deflection element 520, causing the flow of exhaust gases to be deflected along the exterior face of dome-shaped deflection element 520. Dome-shaped deflection element 520 has an exterior surface, a first end of the exterior surface points toward the inlet end of the muffler and widens out at a second end to form a base. The dome-shaped deflection element also has at least two partition openings 522 disposed between the first end and the second end preferably formed at the base end_ The exhaust gases flow through openings 522 in the sides of dome-shaped deflection element 520. Openings 522 are preferably disposed on opposite sides of dome-shaped deflection element 520.
It will be appreciated that although pipe 509 and the dome-shaped deflection element 520 are illustrated herein as substantially axially centered within the housing 501, here too, it is within the scope of the present invention to provide a 3 n on-straight-pipet-iat-extends from -an inlet-the-is-riot ax4ally c nt-e-r-ed-withi;t-~--th housing 501 to a downstream end that is aligned with the apex of dome-shaped deflection element 520, which need not be axially centered within the housing 501.
As discussed above, here too, opening 513 configured in interior partition wall 504 allows exhaust gasses to enter the first chamber 503 and thereby alleviate some excess pressure that may from in the intermediate chamber 517. It will be appreciated that in this embodiment as well, interior partition wall 504 may be configured with a single opening 513 as illustrated herein, or with a plurality of opening to allow passage of exhaust gasses between the first 503 and intermediate 517 chambers.
As the exhaust gases flow through the openings 522 formed at the base of the dome-shaped deflection element 520, a substantial first portion of the exhaust gases continue to flow in the direction of the opening 514 to the perforated pipe 511, thereby creating a low pressure region inside the dome-shaped deflection element 510. Consequently, a second portion of the exhaust gases changes direction and enters (is drawn into) the inside region of dome-shaped deflection element 510 before continuing toward opening 514. Here too, the flow pattern thus created serves to decrease the sounds associated with the exhaust.
Perforated pipe 511 extends from opening 514 through the last chamber 507 to the outlet pipe 512. As the exhaust gases flow through perforated pipe 511, the associated sound waves pass freely through the perforations 516 into the last chamber 507 and are thereby further dissipated. Preferably, as illustrated herein, the 1 S--las"hamber 50-7~ontai s ound-attenuating-material-made from mineral-fibers-or synthetic fibers either individually or in combination, as mentioned above.
With this basic understanding of the general structure of the preferred embodiments 400 and 500 of the muffler of the present invention, it will be appreciated that inlets 408 and 508 are configured for attachment to the exhaust pipe of the vehicle on which the muffler is deployed and therefore may vary in diameter depending on the specifications of the of the vehicle manufacturer.
It will be appreciated that inlets 408 and 508 may be configured as two or more inlet pipes 409 and 509 that come together and have a single downstream end that is aligned with the apex of the deflection element. Similarly, the outlet pipes 412 and 512 may be configured as more than one outlet pipe.
It should be noted that the first chamber 403 and 503 may extend for a distance of 10%-85% of the total length of the muffler 400 and 500. Further, the first chamber may be configured as more than one chamber.
Similarly, the last chamber 407 and 507 may extend for a distance of 5%-80% of the total length of the muffler 400 and 500, and the last chamber may be configured as more than one chamber.
Further, although the sound-attenuating material 415 and 515 is illustrated herein as being deployed in the last chamber 407 and 507, it will be appreciated that sound deadening material may be deployed in any of the first 403 and 503, intermediate 417 and 517 and last 407 and 507 chambers either individually or in combination. Also, the sound-attenuating material may deployed so as to partially fill or fully fill the chamber in which it is deployed.
It will be appreciated that the above descriptions are intended only to serve as examples and that many other embodiments are possible within the spirit and the scope of the present invention.
FIG. 6 is a perspective, cut-open view showing the flow path of exhaust gases through the embodiment of FIG. 5;
FIG. 7 is a perspective, cut open view of a third preferred embodiment of a muffler constructed and operational according to the teachings of the present invention having a pyramidal deflection element; and FIG. 8 is a perspective, cut-open view of a fourth preferred embodiment of a muffler constructed and operational according to the teachings of the present invention having a dome-shaped deflection element.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is a low back-pressure sound-attenuating muffler having-a-Io er__decib~l~utput~har~the pze~io a ffexs o as t4 be usable on regular passenger vehicles.
The principles and operation of low back-pressure sound-attenuating muffler according to the present invention may be better understood with reference to the drawings and the accompanying description.
By way of introduction reference is made to the prior art low back-pressure sound-attenuating mufflers of V.S. Patent Nos. 6,286,623 and 6,776,257 to the present inventor and incorporated herein by reference.
it should be noted that as used herein, references to sequence such as first, intermediate and last refer to the relationship of elements in the drawings and are not intended to limit the scope of the present invention.
Figure 1 shows a cut open view of the muffler 200 of U.S. Patent No.
6,286,623. The muffler 200 consists of an elongated housing 202 having an inlet 206 for introducing the exhaust gases, an outlet 208 for discharging the exhaust gases, a pyramidal partition 250 and converging partitions 240 and 260.
The exhaust gases from the internal combustion engine are introduced into the muffler 200 through the inlet 206. The exhaust gases enter the housing 202 and flow longitudinally through the length of muffler 200 passing first through chamber 212. The exhaust gases exit chamber 212 through an opening in partition 240.
Partition 240 is shaped like a funnel (or truncated pyramid), disposed such that the opening in the partition 240 centers the flow of exhaust gases within housing 202.
The flow exhaust gases then enters the second chamber 214 and encounters the apex 1-5 230-of-pyrarni-dal partition Z-5O; causing-t-he-Howto-lie-dofleeted-alo g he xt iDr faces of pyramidal partition 250 and towards the interior surface of the outer wall of housing 202.
The exhaust gases flow through the four spaces 252 formed by the rugose base of the pyramidal partition 250. A substantial first portion of the exhaust gases continue to flow in the direction of the outlet pipe 208, thereby creating a low pressure region inside the pyramidal partition 250. Consequently, a second portion of the exhaust gases changes direction and enters (is drawn into) the inside region of pyramidal partition 250 before continuing toward the outlet pipe 208. The exhaust gases flow through converging partition 260, which is substantially identical in shape and in disposition to converging partition 240. Thus, the flow of exhaust gases enters the third chamber 216 and is again centered within the housing 202 by the partition outlet 224 before being discharged through outlet pipe 208.
Figure 2 shows a perspective, cut-open view of the muffler 300 of U.S.
Patent No. 6,776,257. Muffler 300 includes an elongated housing 302 having an inlet 306 for introducing the exhaust gases, an outlet 308 for discharging the exhaust gases, a main partition 350, and an aligning partition 340.
The exhaust gases from the internal combustion engine are introduced through the inlet 306. The exhaust gases enter housing 302 and flow longitudinally through the length of muffler 300 passing first through chamber 312. The exhaust gases exit chamber 312 through an opening in partition 340. Partition 340 is preferably shaped like a funnel (or truncated pyramid), and most importantly, is disposed such that the exhaust gas flow is centered within the housing 302 as the ex-haunt aces-enter th,e~--see-ond-chamber 314-and-floe-how of--exact-gases-encounters the top of domed partition 350, causing the flow to be deflected along the exterior face of domed partition 350.
The exhaust gases flow through openings 352 in the sides of domed partition 350 Openings 352 are preferably disposed on opposite sides of domed partition 350.
Subsequently, the exhaust gases continue to flow in the direction of outlet pipe 308, thereby creating a low pressure region inside domed partition 350.
Consequently, a portion of the exhaust gases change direction and enter (are drawn into) the inside of domed partition 350 before continuing in the direction of outlet pipe 308. The exhaust gases flow through converging partition 360, which is advantageously similar in shape and in disposition to converging partition 340, and enter the third chamber 316 before being discharged through outlet pipe 308.
Generally speaking, the embodiments of U.S. Patent Nos. 6,286,623 and 6,776,257 as briefly described above include an inlet chamber, a deflection chamber in which a deflection element is deployed and an outlet chamber.
The first to preferred embodiments of the present invention relate to an improvement that may be used to benefit both of the previous muffler embodiments described above. Specifically, the present invention includes an improved inlet configuration having first and second sequential chambers with a perforated central pipe passing longitudinally through a central region of both chambers for directing the exhaust gases into the third chamber in which the deflection element is deployed. Additionally, the partition separating the first and second chamber has a hole that enables some of the gas to pass from the first chamber into the second 5 chamber et thr-ough-theme-entr-al-pipe.
Described below are two exemplary embodiments of the present invention The first preferred embodiment of Figures 3 and 4 relates to a muffler combining the features of the present invention with the pyramidal partition deflection element of U.S. Patent No. 6,286,623. The second preferred embodiment of Figures 5 and relates to a muffler combining the features of the present invention with the domed partition deflection element of U.S. Patent No. 6,776,257 Referring now to the drawings, Figures 3 and 4 illustrate a muffler 2 generally defined by a housing 4. An inlet 6 is provided in the inlet end of the muffler for introducing exhaust gases into the first chamber 10. The improved inlet configuration has the first chamber 10 and a second chamber 12 sequentially arranged within muffler 2. A perforated pipe 20, with its upstream end 22 partially sealed, passing longitudinally through a central region of both the first 10 and the second 12 chambers such that perforated pipe 20 extends partially into the first chamber 10 and extends the full length of the second chamber 12. Perforated pipe 20 extends at its downstream end 24 through partition 40 and opens into the third chamber 14. The perforations 26a allow the exhaust gases to enter the perforated pipe 20 from the first chamber 10, while perforations 26b allow the exhaust gases to enter the perforated pipe 20 from the second chamber 12. Once the exhaust gases enter perforated pipe 20 they are directed through the interior of perforated pipe 20 and into the third chamber 14. As illustrated here, the perforations 26 are formed over a predetermined percentage of the surface of pipe 20.
The partition 30 separating the first and second chambers includes a I -preferably round-hole-3-2 that-enables-semo--ef-the-gas-to pass-rem-thefirst-chambe 10 into the second chamber 12 without passing through the central perforated pipe 20. Exhaust gases that enter the second chamber 12 then pass through the perforations 26 in the section of perforated pipe 20 deployed in second chamber 12.
It will be appreciated that hole 32 may be of substantially any suitable size and shape.
With this basic understanding of the general structure of the first two chambers of the muffler, it will be appreciated that inlet 6 is configured for attachment to the exhaust pipe of the vehicle on which the muffler is deployed and therefore may vary in diameter depending on the specifications of the of the vehicle manufacturer. It will be appreciated that inlet 6 may be configured as more that one inlet pipe. It will be readily understood that in such an embodiment, the percentages listed herebelow are applied to the combined size of all inlet pipes.
Similarly, the outlet pipe 8 may be configured as more that one outlet pipe and the percentages listed herebelow are applied to the combined size of all outlet pipes.
In order for the muffler of the present invention to perform at an optimum level, perforated pipe 20 has a diameter that is 100%-130% of the diameter of inlet pipe 6. It will be appreciated that perforated pipe 20 may be implemented as more than one perforated pipe as long as the ratio of 100%-130% of the diameter of inlet pipe 6 is maintained. The upstream end 22 of the perforated pipe 20 is partially sealed so as to be 60%-80% open. The perforation holes in the perforated pipe may range from 15mm-S5mm in diameter. Perforations 26a cover between 20%-40% of the surface of perforated pipe 20, while perforations 26b cover 50%-90%
of i 5--tZe-&urface of perforated pipe 20.- 4ole 2-configured-in partit:ion-30-has a-dia ter that is 60%-80% of the diameter of perforated pipe 20. It will be appreciated that hole 32 may be implemented as a plurality of holes configured in partition 30, however, the combined size of the opening still falls within the range of 60%-80%
of the diameter of perforated pipe 20. Further, embodiments in which the second chamber 12 is subdivided into a number of chambers through which perforated pipe 20 passes are within the scope of the present invention. It should be noted that these specifications apply to the embodiment of the present invention described bellow with regard to Figures 5 and 6, as well as any muffler constructed and operational according to the teachings of the present invention.
Similar to the muffler of Figure 1, the flow of exhaust gases is centered within the housing 4 as the exhaust gases leaves the downstream end 24 of the perforated pipe 20, enters the third chamber 14. The flow of exhaust gases encounters the apex of pyramidal partition 50, which is spaced a distance of 20mm 60mm from the downstream end 24 of the perforated pipe 20, causing the flow to be deflected along the exterior faces of pyramidal partition 50 and towards the interior surface of the outer wall of housing 4.
The exhaust gases flow then through the four spaces 52 formed by the rugose base of the pyramidal partition 50. A substantial first portion of the exhaust gases continue to flow in the direction of the outlet pipe 120, thereby creating a low pressure region inside the pyramidal partition 150. Consequently, a second portion of the exhaust gases changes direction and enters (is drawn into) the inside region of pyramidal-partition a0-befor"ont-inuing~-ow,ard-the-outlet-pipe 8 Thhee aus gases-flow through partition 60 and is again centered within the housing 100 as the exhaust gases enter the fourth chamber 16 before being discharged through outlet pipe 8, formed in the outlet end of the muffler.
The arrows in Figure 4 illustrate the flow path of the exhaust gases through this embodiment of the muffler of the present invention.
Figures 5 and 6 illustrate a muffler 102 generally defined by a housing 4, which includes an inlet configuration similar to the embodiment of Figures 3 and 4, therefore, the same reference numerals are used here to refer to corresponding components. It will be appreciated that the specifications relating to component size detailed above apply equally here as well.
An inlet 6 is provided in the inlet end of the muffler for introducing exhaust gases into the first chamber 10. The improved inlet configuration of this embodiment also has the first chamber 10 and a second chamber 12 sequentially arranged within muffler 102. A perforated pipe 20, with its upstream end 22 sealed, passing longitudinally through a central region of both the first 10 and the second 12 chambers such that perforated pipe 20 extends partially into the first chamber 10 and extends the full length of the second chamber 12. Perforated pipe 20 extends at its downstream end 24 through partition 40 and opens into the third chamber 14.
The perforations 26 allow the exhaust gases to enter the perforated pipe 20 so as to be directed through the interior of perforated pipe 20 and into the third chamber 14.
The partition 30 separating the first and second chambers includes a preferably round hole 32 that enables some of the gas to pass from the first chamber 1 5-10-into the-se wnd-chamber T-2-ithout p- as ing-through-the-centr-al-per-for-atzdpipe-20. Exhaust gases that enter the second chamber 12 then pass through the perforations 26 in the section of perforated pipe 20 deployed in second chamber 12.
It will be appreciated that in this embodiment as well, hole 32 may be of substantially any suitable size and shape.
Similar to the muffler of Figure 2, the exhaust gas flow is centered within the housing 4 as the exhaust gases leaves the downstream end 24 of the perforated pipe 20, and enters the third chamber 14 and the flow of exhaust gases encounters the top of domed partition 150, causing the flow of exhaust gases to be deflected along the exterior face of domed partition 150. Dome-shaped partition 150 having an exterior surface, a first end of the exterior surface points toward the inlet end of the muffler, and widening out at a second end to form a base, said dome-shaped partition having at least two partition openings disposed between said first end and said second end of said exterior surface The exhaust gases flow through openings 152 in the sides of domed partition 150. Openings 152 are preferably disposed on opposite sides of domed partition 150.
Subsequently, the exhaust gases continue to flow in the direction of outlet pipe 8 formed in the outlet end of the muffler, thereby creating a low pressure region inside domed partition 150. Consequently, a portion of the exhaust gases change direction and enter (are drawn into) the inside of domed partition 150 before continuing in the direction of outlet pipe 8. The exhaust gases flow through an opening (not shown) partition 160, and enter the fourth chamber 16 before being -15 disc-harmed--thr-ough-outlet-pipe-S:
The arrows in Figure 6 illustrate the flow path of the exhaust gases through this embodiment of the muffler of the present invention.
The embodiment of Figure 7 relates to a third preferred embodiment 400 of the muffler combining features of the present invention with the pyramidal partition deflection element of U.S. Patent No. 6,286,623.
Figure 7 illustrates muffler 400 of the present invention generally defined by a housing 401 and end walls 402 and 406. An inlet 408 for introducing exhaust gases into the muffler 400 is provided in end wall 402. The inlet configuration. of the mufflers of the present invention includes an inlet pipe 409 that is axially centered within the housing 401 and extends from the inlet 408 through the first chamber 403 and opens at its downstream end into the intermediate chamber 417 sequentially arranged within muffler 400.
As the flow of exhaust gases leaves the downstream end of pipe 409 and enters the intermediate chamber 417, the flow of exhaust gases encounters the apex of pyramidal deflection element 410 causing the flow to be deflected along the exterior faces of pyramidal deflection element 410 and towards the interior surface of the outer wall of housing 401. It will be appreciated that although pipe 409 and the apex of pyramidal deflection element 410 are illustrated herein as substantially axially centered within the housing 401, it is within the scope of the present invention to provide a non-straight pipe that extends from an inlet that is not axially centered within the housing 401 to a downstream end that is aligned with the apex of pyramidal deflection element 410, which need not be axially centered within the Sousing-404:
Opening 413 configured in interior partition wall 404 allows exhaust gasses to enter the first chamber 403 and thereby alleviate some excess pressure that may from in the intermediate chamber 417. It will be appreciated that interior partition wall 404 may be configured with a single opening 413 as illustrated herein, or with a plurality of opening to allow passage of exhaust gasses between the first 403 and intermediate 417 chambers.
The exhaust gases then flow through the four spaces 418 formed at the base of the pyramidal deflection element 410. A substantial first portion of the exhaust gases continue to flow in the direction of the opening 414 to the perforated pipe 411, thereby creating a low pressure region inside the pyramidal deflection element 410. Consequently, a second portion of the exhaust gases changes direction and enters (is drawn into) the inside region of pyramidal deflection element 410 before continuing toward opening 414. The flow pattern thus created serves to decrease the sounds associated with the exhaust.
Perforated pipe 411 extends from opening 414 through the last chamber 407 to the outlet pipe 412. As the exhaust gases flow through perforated pipe 411, the associated sound waves pass freely through the perforations 416 into the last chamber 407 and are thereby further dissipated. Preferably, as illustrated herein, the last chamber 407 contains a sound-attenuating material made from mineral fibers or synthetic fibers either individually or in combination. Such fibers include, but are not limited to, Asbestos fibers, basalt fibers, mineral wool, glass wool, metal wools such as steel wool and bronze wool, carbon fiber and aramid fiber such as Kevlaro.
-1-5 T-he-embodiment-of figure- Vr-efates-t~~s cond-pr-e-fe dembodlment-50Q
of the muffler combining the features of the present invention with the dome-shaped deflection element of U.S. Patent No. 6,776,257. Muffler 500 is generally defined by a housing 501 and end walls 502 and 506. An inlet 508 for introducing exhaust gases into the muffler 500 is provided in end wall 502. The inlet configuration of the mufflers of the present invention includes an inlet pipe 509 that is axially centered within the housing 501 and extends from the inlet 508 through the first chamber 503 and opens at its downstream end into the intermediate chamber 517 sequentially arranged within muffler 500.
As the flow of exhaust gases leaves the downstream end of pipe 509 and enters the intermediate chamber 517, the flow of exhaust gases encounters the top of the dome-shaped deflection element 520, causing the flow of exhaust gases to be deflected along the exterior face of dome-shaped deflection element 520. Dome-shaped deflection element 520 has an exterior surface, a first end of the exterior surface points toward the inlet end of the muffler and widens out at a second end to form a base. The dome-shaped deflection element also has at least two partition openings 522 disposed between the first end and the second end preferably formed at the base end_ The exhaust gases flow through openings 522 in the sides of dome-shaped deflection element 520. Openings 522 are preferably disposed on opposite sides of dome-shaped deflection element 520.
It will be appreciated that although pipe 509 and the dome-shaped deflection element 520 are illustrated herein as substantially axially centered within the housing 501, here too, it is within the scope of the present invention to provide a 3 n on-straight-pipet-iat-extends from -an inlet-the-is-riot ax4ally c nt-e-r-ed-withi;t-~--th housing 501 to a downstream end that is aligned with the apex of dome-shaped deflection element 520, which need not be axially centered within the housing 501.
As discussed above, here too, opening 513 configured in interior partition wall 504 allows exhaust gasses to enter the first chamber 503 and thereby alleviate some excess pressure that may from in the intermediate chamber 517. It will be appreciated that in this embodiment as well, interior partition wall 504 may be configured with a single opening 513 as illustrated herein, or with a plurality of opening to allow passage of exhaust gasses between the first 503 and intermediate 517 chambers.
As the exhaust gases flow through the openings 522 formed at the base of the dome-shaped deflection element 520, a substantial first portion of the exhaust gases continue to flow in the direction of the opening 514 to the perforated pipe 511, thereby creating a low pressure region inside the dome-shaped deflection element 510. Consequently, a second portion of the exhaust gases changes direction and enters (is drawn into) the inside region of dome-shaped deflection element 510 before continuing toward opening 514. Here too, the flow pattern thus created serves to decrease the sounds associated with the exhaust.
Perforated pipe 511 extends from opening 514 through the last chamber 507 to the outlet pipe 512. As the exhaust gases flow through perforated pipe 511, the associated sound waves pass freely through the perforations 516 into the last chamber 507 and are thereby further dissipated. Preferably, as illustrated herein, the 1 S--las"hamber 50-7~ontai s ound-attenuating-material-made from mineral-fibers-or synthetic fibers either individually or in combination, as mentioned above.
With this basic understanding of the general structure of the preferred embodiments 400 and 500 of the muffler of the present invention, it will be appreciated that inlets 408 and 508 are configured for attachment to the exhaust pipe of the vehicle on which the muffler is deployed and therefore may vary in diameter depending on the specifications of the of the vehicle manufacturer.
It will be appreciated that inlets 408 and 508 may be configured as two or more inlet pipes 409 and 509 that come together and have a single downstream end that is aligned with the apex of the deflection element. Similarly, the outlet pipes 412 and 512 may be configured as more than one outlet pipe.
It should be noted that the first chamber 403 and 503 may extend for a distance of 10%-85% of the total length of the muffler 400 and 500. Further, the first chamber may be configured as more than one chamber.
Similarly, the last chamber 407 and 507 may extend for a distance of 5%-80% of the total length of the muffler 400 and 500, and the last chamber may be configured as more than one chamber.
Further, although the sound-attenuating material 415 and 515 is illustrated herein as being deployed in the last chamber 407 and 507, it will be appreciated that sound deadening material may be deployed in any of the first 403 and 503, intermediate 417 and 517 and last 407 and 507 chambers either individually or in combination. Also, the sound-attenuating material may deployed so as to partially fill or fully fill the chamber in which it is deployed.
It will be appreciated that the above descriptions are intended only to serve as examples and that many other embodiments are possible within the spirit and the scope of the present invention.
Claims (17)
1. A muffler for an internal combustion engine comprising:
(a) a housing having an inlet end with at least one inlet opening formed for a flow of exhaust gases into said housing and an outlet end with an outlet opening formed for a discharge of exhaust gases from said housing;
(b) a first chamber and a second chamber sequentially arranged within said housing;
(c) a perforated pipe passing longitudinally through a central region of both said first and said second chambers such that said perforated pipe extends partially into said first chamber, extends a full length of said second chamber;
wherein said perforations allow said exhaust gases to enter said perforated pipe so as to be directed through an interior of said perforated pipe and into a third chamber and a partition separating said first and said second chambers includes a hole that enables some of said exhaust gases to pass from said first chamber into the second chamber without passing through said central perforated pipe.
(a) a housing having an inlet end with at least one inlet opening formed for a flow of exhaust gases into said housing and an outlet end with an outlet opening formed for a discharge of exhaust gases from said housing;
(b) a first chamber and a second chamber sequentially arranged within said housing;
(c) a perforated pipe passing longitudinally through a central region of both said first and said second chambers such that said perforated pipe extends partially into said first chamber, extends a full length of said second chamber;
wherein said perforations allow said exhaust gases to enter said perforated pipe so as to be directed through an interior of said perforated pipe and into a third chamber and a partition separating said first and said second chambers includes a hole that enables some of said exhaust gases to pass from said first chamber into the second chamber without passing through said central perforated pipe.
2. The muffler of claim 1, wherein said perforated pipe has a diameter that is 100%-130% of the diameter of said inlet opening.
3. The muffler of claim 1, wherein an upstream end of said perforated pipe is partially sealed.
4. The muffler of claim 3, wherein said upstream end of said perforated pipe is 60%-80% open.
5. The muffler of claim 1, wherein perforations in said perforated pipe extending partially into said first chamber cover 20%-40% of a surface of said perforated pipe and, perforations in said perforated pipe extending said full length of said second chamber cover 50%-90% of said surface of said perforated pipe.
6. The muffler of claim 1, further including:
(d) said third chamber containing a deflection element, said perforated pipe extending so as to open at its downstream end into said third chamber, thereby directing said exhaust gases toward said deflection element; and (e) a fourth chamber configured to channel a flow of gas to said outlet opening.
(d) said third chamber containing a deflection element, said perforated pipe extending so as to open at its downstream end into said third chamber, thereby directing said exhaust gases toward said deflection element; and (e) a fourth chamber configured to channel a flow of gas to said outlet opening.
7. The muffler of claim 6, wherein said deflection element is a hollow pyramid having interior surfaces and exterior surfaces joining at a first end to form a pyramidal apex, said pyramidal apex pointing toward said inlet end of the muffler and extending at a second end to form an open base interconnected to a partition separating said third and said fourth cambers.
8. The muffler of claim 6, wherein said deflection element is a dome-shaped partition having an exterior surface, a first end of said exterior surface pointing toward said inlet end of the muffler, and widening out at a second end to form a base interconnected to a partition separating said third and said fourth cambers.
9. A muffler for an internal combustion engine comprising:
(a) a housing having an inlet end with an inlet opening formed for a flow of exhaust gases into said housing and an outlet end with an outlet opening formed for a discharge of exhaust gases from said housing;
(b) at least a first chamber, an intermediate and a last chamber sequentially arranged within said housing, said intermediate chamber containing a deflection element chosen from a group including:
(i) a hollow pyramid; and (ii) a dome-shaped partition;
(c) a pipe passing longitudinally through said first chamber so as to open at its downstream end into said intermediate chamber, thereby directing said exhaust gases toward said deflection element; and (d) a perforated pipe extending through said last chamber, said perforated pipe having an upstream opening into said intermediate chamber and configured to channel said exhaust gas to said outlet opening.
(a) a housing having an inlet end with an inlet opening formed for a flow of exhaust gases into said housing and an outlet end with an outlet opening formed for a discharge of exhaust gases from said housing;
(b) at least a first chamber, an intermediate and a last chamber sequentially arranged within said housing, said intermediate chamber containing a deflection element chosen from a group including:
(i) a hollow pyramid; and (ii) a dome-shaped partition;
(c) a pipe passing longitudinally through said first chamber so as to open at its downstream end into said intermediate chamber, thereby directing said exhaust gases toward said deflection element; and (d) a perforated pipe extending through said last chamber, said perforated pipe having an upstream opening into said intermediate chamber and configured to channel said exhaust gas to said outlet opening.
10. The muffler of claim 1, wherein said pipe passes longitudinally through an axially central region of said first chamber.
11. The muffler of claim 1, wherein a partition separating said first and said intermediate chambers includes a hole that enables some of said exhaust gases to pass freely between said first chamber and said intermediate chamber.
12. The muffler of claim 1, wherein said first chamber extends between 10%-85% of the total length of said housing.
13. The muffler of claim 1, wherein said last chamber extends between 5%-80% of the total length of said housing.
14. The muffler of claim 1, further including a sound-attenuating material deployed in at least one of said first chamber, said intermediate chamber and said last chamber.
15. The muffler of claim 6, wherein said sound -attenuating material is configured from at least one chosen from the group that includes, mineral fibers and synthetic fibers.
16. The muffler of claim 1, wherein said hollow pyramid deflection element has interior surfaces and exterior surfaces joining at a first end to form a pyramidal apex, said pyramidal apex pointing toward said inlet end of the muffler and extending at a second end to form an open base interconnected to a partition separating said intermediate and said last cambers.
17. The muffler of claim 1, wherein said dome-shaped partition deflection element has an exterior surface, a first end of said exterior surface pointing toward said inlet end of the muffler, and widening out at a second end to form an open base interconnected to a partition separating said intermediate and said third cambers.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US12/170,443 US7708114B2 (en) | 2008-07-10 | 2008-07-10 | Sound-attenuating muffler having reduced back pressure |
| US12/170,443 | 2008-07-10 | ||
| US12/245,870 US7708115B2 (en) | 2008-10-06 | 2008-10-06 | Sound-attenuating muffler having reduced back pressure |
| US12/245,870 | 2008-10-06 | ||
| PCT/IB2009/052827 WO2010004476A1 (en) | 2008-07-10 | 2009-06-30 | Improved sound-attenuating muffler having reduced back pressure |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2730209A1 true CA2730209A1 (en) | 2010-01-14 |
Family
ID=41506727
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2730209A Abandoned CA2730209A1 (en) | 2008-07-10 | 2009-06-30 | Improved sound-attenuating muffler having reduced back pressure |
Country Status (4)
| Country | Link |
|---|---|
| CN (1) | CN102112710A (en) |
| BR (1) | BRPI0915748A2 (en) |
| CA (1) | CA2730209A1 (en) |
| WO (1) | WO2010004476A1 (en) |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2881852A (en) * | 1956-06-14 | 1959-04-14 | Gen Motors Corp | Exhaust muffler means |
| US6241044B1 (en) * | 1999-02-05 | 2001-06-05 | Komatsu Ltd. | Exhaust silencer and communicating pipe thereof |
| US6776257B1 (en) * | 2003-05-13 | 2004-08-17 | Silent Exhaust Systems Ltd. | Sound-attenuating muffler having reduced back pressure |
-
2009
- 2009-06-30 CN CN200980127831.2A patent/CN102112710A/en active Pending
- 2009-06-30 BR BRPI0915748A patent/BRPI0915748A2/en not_active IP Right Cessation
- 2009-06-30 CA CA2730209A patent/CA2730209A1/en not_active Abandoned
- 2009-06-30 WO PCT/IB2009/052827 patent/WO2010004476A1/en not_active Ceased
Also Published As
| Publication number | Publication date |
|---|---|
| BRPI0915748A2 (en) | 2019-09-24 |
| WO2010004476A1 (en) | 2010-01-14 |
| CN102112710A (en) | 2011-06-29 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |