Acoustic muffler

• US 4,846,302 A
• Filed: 08/08/1986
• Issued: 07/11/1989
• Est. Priority Date: 08/08/1986
• Status: Expired due to Fees

• Current Assignee: Tenneco Incorporated (Apollo Global Management, Inc.)
• Original Assignee: Tenneco Incorporated (Apollo Global Management, Inc.)
• Inventors: Hetherington, Theodore W.
• Primary Examiner(s): Fuller, Benjamin R.
• Application Number:
  US06/894,634
• Time in Patent Office: 1,068 Days
• Field of Search: 181/241, 181/243, 181/256, 181/265, 181/266, 181/258, 181/272, 181/247-255, 181/223, 181/231, 55/276, 55/DIG. 30, 55/DIG. 31
• US Class Current: 181/243
• CPC Class Codes: F01N 1/02 by using resonance
• CPC Class Codes: F01N 1/084 the gases flowing through the silencer two or more times longitudinally in opposite directions, e.g. using parallel or concentric tubes
• CPC Class Codes: F01N 1/10 in combination with sound-absorbing materials F01N1/125 takes precedence
• CPC Class Codes: F01N 1/24 by using sound-absorbing materials F01N1/04, F01N1/06, F01N1/10, F01N1/14, F01N1/16 take precedence
• CPC Class Codes: F01N 2310/02 Mineral wool, e.g. glass wool, rock wool, asbestos or the like
• CPC Class Codes: F01N 2490/155 being disposed one after the other in flow direction
• CPC Class Codes: Y10S 55/30 Exhaust treatment

Abstract

A sound attenuating muffler for motor vehicle exhaust systems contains a fibrous glass cartridge with a binder-hardened outer shell surrounding a soft fibrous core through which a gas flow tube extends.

Claims

1. An acoustic muffler for attenuating sound in motor vehicle exhaust gases comprising a housing having inlet and outlet means for gas flow, means for providing a chamber having an annular outer wall defining a shape of the chamber, a cartridge composed of a soft core of unbonded fibrous glass sound absorbent material and including an annular fibrous hard outer shell of bonded fibrous glass sound absorbent material preformed to and retaining said chamber shape, gas flow means in said cartridge for allowing gas to flow through said soft core, said hard outer shell confining and holding said soft core so that said cartridge is adapted to be handled as a one piece component in assembly of the muffler, said cartridge having a slip fit inside said chamber with said outer shell engaging said annular wall, and gas passage means for the flow of exhaust gas between the inlet and outlet means and providing for acoustic communication of the exhaust gas with the gas flow means for the core of said cartridge.

2. A muffler as set forth in claim 1 wherein said gas flow means comprises at least one hole extending through said core and a preforated sleeve of high temperature withstanding material extending along a length of the hole.

3. A muffler as set forth in claim 2 wherein said gas passage means includes a gas tube extending through said perforated sleeve and having openings into the perforated sleeve to provide said acoustic communication.

4. A muffler as set forth in claim 1 wherein the fibers of said fibrous glass are about 7 microns in diameter and said fibrous glass core is unbonded and unlubricated.

5. An acoustic component for a motor vehicle exhaust muffler provided with inlet and outlet means for gas flow comprising a cartridge composed of a soft core of unbonded sound absorbent fibrous glass and a hard, molded annular outer shell of fibrous glass surrounding and containing said core to confine and hold said core and preformed to a predetermined shape whereby said fibrous glass cartridge may be handled efficiently in production and assembly of a muffler and inserted by slip fit into a muffler housing, and gas flow means through said core for allowing gas to flow from said inlet to said outlet means.

6. A component as set forth in claim 5 wherein said gas flow means comprises at least one hole extending longitudinally through said core and a preforated sleeve of high temperature withstanding material extending along a length of the hole.

7. An acoustic muffler for attenuating sound in motor vehicle exhaust gases comprising a tubular housing having inlet and outlet means for gas flow, said housing having a transverse chamber and at least one longitudinally extending gas flow tube passing through the chamber, a cartridge sized and shaped to fill said chamber and having an opening through said cartridge for passage of said gas flow tube, said cartridge being composed entirely of non-metallic fibrous sound absorbent material and having a soft core of said fibrous material in unbonded condition and a hard outer tubular shell of bonded fibrous material conforming in shape and and size to said tubular housing, whereby said cartridge is adapted to slip fit as a unit into said tubular housing and into said chamber with an outside of the outer tubular shell substantially in contact with an inside of said tubular housing, said hard outer tubular shell confining and holding said soft core fibrous material so that said cartridge may be handled efficiently in production and during assembly of said muffler.

8. A muffler as set forth in claim 7 including a perforated sleeve of high temperature withstanding material extending along a length of said opening in said cartridge, said gas flow tube extending through said sleeve.