초록 ▼

The invention relates to an exhaust silencer or muffler for an internal combustion engine, in particular a silencer with the damping characteristics of a resonator with the absorptive characteristics of a dissipative silencer. The silencer of the present invention provides an improved silencer or mu

The invention relates to an exhaust silencer or muffler for an internal combustion engine, in particular a silencer with the damping characteristics of a resonator with the absorptive characteristics of a dissipative silencer. The silencer of the present invention provides an improved silencer or muffler for use with an internal combustion engine that incorporates both a dissipative silencer and a resonator in a single muffler assembly suitable for use with standard automotive construction techniques.

대표청구항 ▼

We claim: 1. A silencer for an internal combustion engine comprising: an outer shell having a body and first and second ends; an exhaust duct carrying exhaust gasses through said body; a dissipative silencer positioned within said body and surrounding said exhaust duct; a Helmholtz resonator compri

We claim: 1. A silencer for an internal combustion engine comprising: an outer shell having a body and first and second ends; an exhaust duct carrying exhaust gasses through said body; a dissipative silencer positioned within said body and surrounding said exhaust duct; a Helmholtz resonator comprising a chamber and a throat positioned within said body, wherein said exhaust duct is a perforated exhaust duct and at least one perforation is acoustically coupled to said resonator throat, said throat of said Helmholtz resonator running substantially the length of said dissipative silencer; and a connector component interconnecting said dissipative silencer and said Helmholtz resonator. 2. The silencer of claim 1, wherein at least one perforation is acoustically coupled to said dissipative silencer. 3. The silencer of claim 1, wherein said exhaust duct penetrates the dissipative silencer and the Helmholtz resonator chamber, said exhaust duct having a plurality of perforations along first and second portions of said duct and no perforations along a third portion of said duct, wherein said first portion of the exhaust duct is acoustically coupled to the throat of the Helmholtz resonator, said second portion of the duct is acoustically coupled to the dissipative silencer and said third portion of the duct penetrates the resonator. 4. The silencer of claim 1, wherein the chamber of said resonator includes a porous material. 5. The silencer of claim 4, wherein said porous material is a fibrous material. 6. The silencer of claim 4, wherein said porous material is selected from the group consisting essentially of glass fibers and mineral wool fibers. 7. The silencer of claim 6, wherein said porous material is a high temperature resistant glass fiber. 8. The silencer of claim 1, wherein said dissipative silencer includes at least one baffle within said dissipative silencer. 9. The silencer of claim 8, wherein said at least one baffle separates the dissipative silencer into multiple independent acoustic chambers. 10. The silencer of claim 1, further comprising: a first end of the silencer; and a second end of the silencer, the chamber of the Helmholtz resonator being positioned at the second end of the silencer wherein the dissipative silencer is positioned between the first and second ends of the silencer, and the throat of the Helmholtz resonator is acoustically coupled to the exhaust duct adjacent the first end of the silencer. 11. The silencer of claim 10, wherein exhaust is input into the silencer at the first end of the silencer. 12. The silencer of claim 10, wherein exhaust is input into the silencer at the second end of the silencer. 13. The silencer of claim 10, wherein the throat has a generally annular cross section. 14. The silencer of claim 10, wherein the throat has a generally circular cross section. 15. The silencer of claim 1 further comprising: a fibrous fill material within said resonator. 16. The silencer of claim 15 wherein said resonator includes at least one wall and the fibrous fill material lines at least one wall of said resonator. 17. The silencer of claim 1 further comprising: at least one baffle within said dissipative silencer. 18. A silencer for an internal combustion engine comprising: an outer shell having a body and first and second ends; an exhaust duct having a plurality of perforations along a first and a second portion of said duct; a resonator comprising a chamber and a throat positioned within said body, wherein said throat is acoustically coupled to at least one perforation in said first section of said exhaust duct; and a dissipative silencer positioned within said body and surrounding said second portion of said exhaust duct; wherein said exhaust duct penetrates the dissipative silencer and the resonator chamber, said exhaust duct having a plurality of perforations along a first and second portion of said duct and a third portion of said duct having no perforations, wherein said first section of the duct is acoustically coupled to the throat of the resonator, said second section of the duct is acoustically coupled to the dissipative silencer and said third section of the duct penetrates the resonator; and a connector component interconnecting said dissipative silencer and said resonator; wherein said throat of said resonator runs substantially the length of said dissipative silencer. 19. The silencer of claim 18, wherein the chamber of the resonator is positioned at a second end of the outer shell, said dissipative silencer being positioned between said first and second ends, and wherein the throat of the resonator is acoustically coupled to the exhaust duct adjacent the first end of the shell. 20. The silencer of claim 19, wherein exhaust is input into the silencer at the first end of the chamber. 21. The silencer of claim 19, wherein exhaust is input into the silencer at the second end of the silencer. 22. The silencer of claim 19, wherein the throat has a generally annular cross section and encompasses the dissipative silencer. 23. The silencer of claim 19, wherein the throat has a generally circular cross section. 24. The silencer of claim 18 further comprising: a fibrous fill material within said resonator. 25. The silencer of claim 24 wherein said resonator includes at least one wall and the fibrous fill material lines at least one wall of said resonator. 26. The silencer of claim 18 further comprising: at least one baffle within said dissipative silencer. 27. A silencer comprising: an outer shell having a body and first and second ends; a resonator including a chamber and a throat positioned within said body; a dissipative silencer positioned within said body; and an exhaust duct having a first perforated portion and a second perforated portion, said first and second perforated portions being in fluid communication and separated by said throat of said resonator, said exhaust duct carrying exhaust gasses through said body; wherein said exhaust duct penetrates the dissipative silencer and extends the length of said resonator chamber and said dissipative silencer; and wherein said first and second portions of said exhaust duct are positioned in a substantially horizontal orientation and centrally located within said outer shell to provide substantially equal amounts of acoustic fill material on opposing sides of said exhaust duct; and wherein said chamber of said resonator is positioned circumferentially around said dissipative chamber. 28. The silencer of claim 27, wherein said first and second perforated portions are substantially equal in length. 29. The silencer of claim 27, the dissipative silencer being positioned between the first and second ends and the throat of the resonator being acoustically coupled to the exhaust duct. 30. The silencer of claim 29, wherein exhaust is input into the silencer at the first end of the outer shell. 31. The silencer of claim 29, wherein exhaust is input into the silencer at the second end of the outer shell. 32. The silencer of claim 29, wherein the throat has a generally annular cross section and encompasses the dissipative silencer. 33. The silencer of claim 29, wherein the throat has a generally circular cross section. 34. The silencer of claim 27 further comprising: a fibrous fill material within said resonator. 35. The silencer of claim 34 wherein said resonator includes at least one wall and the fibrous fill material lines at least one wall of said resonator. 36. The silencer of claim 27 further comprising: at least one baffle within said dissipative silencer. 37. A silencer comprising: an outer shell having first and second ends; a resonator comprising a chamber and a throat positioned within said outer shell; a dissipative silencer positioned within said body and including acoustic fill material; an inlet exhaust duct entering the outer shell through said first end, carrying exhaust gasses through said dissipative silencer, said inlet exhaust duct being centrally located within said outer shell to provide substantially equal amounts of said acoustic fill material on opposing sides of said exhaust duct; an outlet exhaust duct penetrating said resonator and exiting through said second end, said outlet exhaust duct being offset from said inlet exhaust duct; an intermediate chamber within said outer shell in fluid communication with said first and second exhaust ducts and said resonator throat; and a baffle within said dissipative silencer separating the silencer into separate acoustical chambers, said acoustic fill material being in both said chambers. 38. The silencer of claim 37 further comprising: a fibrous fill material within said resonator. 39. The silencer of claim 38 wherein said resonator further comprises: at least one wall and the fibrous fill material lines at least one wall of said resonator. 40. The silencer of claim 37 further comprising: a plurality of baffles within said dissipative silencer. 41. A silencer comprising: an outer shell having first and second ends; a resonator comprising a chamber and a throat positioned within said outer shell, said resonator including a hollow wall separating said throat from said chamber; a dissipative silencer positioned within said body; an inlet exhaust duct entering the outer shell through said first end, carrying exhaust gasses through said dissipative silencer, said first exhaust duct having a plurality of perforations within said dissipative silencer and being aligned with said throat; an outlet exhaust duct penetrating said resonator and exiting through said second end, said outlet exhaust duct being located adjacent said throat such that said throat is defined between said outlet exhaust duct and said wall; an intermediate chamber within said outer shell in fluid communication with said inlet and outlet exhaust ducts and said throat of said resonator; and a fibrous fill material within said resonator, said fibrous fill material lining said resonator and filling said hollow wall. 42. The silencer of claim 41 wherein said resonator further comprises: at least one wall and the fibrous fill material lines at least one wall of said resonator. 43. The silencer of claim 41 further comprising: a plurality of baffles within said dissipative silencer.