Noise attenuation assembly

• US 20040149514A1
• Filed: 02/05/2003
• Published: 08/05/2004
• Est. Priority Date: 02/05/2003
• Status: Active Grant

• Current Assignee: ET US Holdings LLC (Forvia SE)
• Original Assignee: Arvin Technologies, Inc. (Meritor, Inc. (Nevada))
• Inventors: Bogard, Joseph T.
• Granted Patent: US 6,913,112 B2
• Time in Patent Office: Days
• US Class Current: 181/252
• CPC Class Codes: F01N 1/003 by using dead chambers communicating with gas flow passages resonance chambers F01N1/02; chambers containing sound-absorbing materials F01N1/24
• CPC Class Codes: F01N 1/04 having sound-absorbing materials in resonance chambers
• CPC Class Codes: F01N 1/10 in combination with sound-absorbing materials F01N1/125 takes precedence

Abstract

The present invention provides a noise attenuation assembly having at least one noise prevention pad disposed within an annular gap formed between a gas passage tube and an overlap tube. The noise prevention pad prevents the two tubes from becoming in contact during thermal expansion of the tubes, and allows the tubes to contract without causing “Tick and Ping” noise, during a cool down.

Claims

1. A noise attenuation assembly comprising:

a shell defining an interior chamber;

a passage tube having an inlet end coupled to a first end of said shell and an outlet end coupled to a second end of said shell;

an overlap tube concentric to and surrounding an overlap portion of said passage tube, said overlap tube forms an annular gap with said overlap portion of said passage tube, said overlap portion of said passage tube defining at least one opening in communication with said annular gap, said annular gap having a closed end and an open end in communication with said interior chamber; and

at least one noise prevention pad disposed within said annular gap, said noise prevention pad having a first surface in contact with said overlap portion of said passage tube, and a second surface in contact with said overlap tube.

2. The noise attenuation assembly of claim 1, wherein said passage tube has an inner wall defining a gas passage, and an outer wall having said noise prevention pad attached thereon.

3. The noise attenuation assembly of claim 2, wherein said noise prevention pad is spot welded to said outer wall of said passage tube.

4. The noise attenuation assembly of claim 1, wherein a plurality of said noise prevention pads is spaced along the circumference of said outer wall of said passage tube, forming a plurality of channels between said noise prevention pads.

5. The noise attenuation assembly of claim 1, wherein said noise prevention pad is made of a heat resistant material.

6. The noise attenuation assembly of claim 5, wherein said noise prevention pad includes a steel wool pad.

7. The noise attenuation assembly of claim 5 wherein said noise prevention pad includes a stainless steel wool pad.

8. The noise attenuation assembly of claim 7, wherein said stainless steel wool pad defines fine needles protruding from said first surface.

9. The noise attenuation assembly of claim 5, wherein said noise prevention pad is a ceramic material.

10. A pipe assembly comprising:

an inner pipe defining a gas passage;

an outer pipe defining another gas passage, said outer pipe having an overlap portion surrounding an overlap portion of said inner pipe;

said another gas passage in communication with said gas passage of said inner pipe;

said overlap portions forms an annular gap open at an overlap end of said outer pipe; and

a least one noise prevention pad disposed within said annular gap keeping said overlap portions from coming in contact.

11. The pipe assembly of claim 10, wherein said inner pipe has an outer wall and said noise prevention pad attached thereon.

12. The pipe assembly of claim 11, wherein said noise prevention pad is spot welded to said outer wall of said inner pipe.

13. The pipe assembly of claim 11, wherein each of said noise prevention pads is disposed along the circumference of said outer wall of said inner pipe, leaving a plurality of channels therebetween for sound communication.

14. The pipe assembly of claim 10, wherein said noise prevention pad is made of a heat resistant material.

15. The pipe assembly of claim 14, wherein said noise prevention pad includes a steel wool pad.

16. The pipe assembly of claim 14 wherein said noise prevention pad includes a stainless steel wool pad.

17. The pipe assembly of claim 16, wherein said stainless steel wool pad defines fine needles protruding from said first surface.

18. The pipe assembly of claim 14, wherein said noise prevention pad is made of a ceramic material.