Flutter dampened exhaust valve

1. A snap-action valve assembly for an exhaust system comprising:

a first conduit extending along a central axis to define an exhaust passageway therein;

a valve flap disposed within said exhaust passageway for controlling exhaust flow through said exhaust passageway;

a shaft supporting said valve flap in said exhaust passageway for rotation about a pivot axis between a closed position and an open position; and

a mass damper external to said first conduit that is rotatably coupled to said shaft such that said mass damper rotates with said shaft, said mass damper including a linear segment extending along a primary mass damper axis between a pair of damper ends, a first transverse segment, and a second transverse segment, said first and second transverse segments extending from said pair of damper ends, and each of said first and second transverse segments extending in a transverse direction relative to said primary mass damper axis.

2. The snap-action valve assembly of claim 1 , wherein said primary mass damper axis is transverse to said pivot axis.

3. The snap-action valve assembly of claim 2 , wherein said linear segment and said first and second transverse segments create a distributed mass around said pivot axis that has an inertial value that ranges from 250 to 400 gram-square millimeters.

4. The snap-action valve assembly of claim 2 , wherein said first and second transverse segments extend from said pair of damper ends in opposite transverse directions such that said first and second transverse segments are transverse to both said primary mass damper axis and said pivot axis.

5. The snap-action valve assembly of claim 2 , wherein said first and second transverse segments extend from said pair of damper ends in identical transverse directions such that said first and second transverse segments are transverse to said primary mass damper axis and parallel to said pivot axis giving said mass damper a U-like shape.

6. The snap-action valve assembly of claim 2 , wherein said first and second transverse segments extend from said pair of damper ends in opposite directions such that said first and second transverse segments are transverse to both said primary mass damper axis and said pivot axis and wherein said first and second transverse segments are curved giving said mass damper a S-like shape.

7. The snap-action valve assembly of claim 2 , wherein said first and second transverse segments extend from said pair of damper ends in a common plane and curve around at least part of said first conduit giving said mass damper a C-like shape.

8. The snap-action valve assembly of claim 2 , wherein said first and second transverse segments are equally spaced from said pivot axis.

9. The snap-action valve assembly of claim 2 , wherein said first and second transverse segments are unevenly spaced from said pivot axis.

10. The snap-action valve assembly of claim 9 , wherein said linear segment includes a flattened portion of reduced cross-sectional width between said pivot axis and said first transverse segment.

11. The snap-action valve assembly of claim 9 , wherein said linear segment is attached to said shaft such that said primary mass damper axis is vertically oriented when said valve flap is positioned half way between said closed position and said open position.

12. The snap-action valve assembly of claim 2 , wherein said shaft includes an axle portion, an external shaft segment, a lever arm, and a spring attachment arm, wherein at least part of said axle portion is disposed within said first conduit, wherein said external shaft segment, said lever arm, and said spring attachment arm are external to said first conduit, wherein said valve flap is carried on said axle portion such that said axle portion of said shaft rotates with said valve flap, wherein said axle portion is co-axially aligned with said pivot axis of said valve flap, wherein said mass damper is attached to said external shaft segment, wherein said axle portion extends between said external shaft segment and said lever arm, wherein said spring attachment arm defines a spring attachment arm axis that is parallel to and spaced from said pivot axis, wherein said lever arm extends transversely between said axle portion and said spring attachment arm of said shaft, and wherein said first conduit includes an anchor post extending outwardly from said first conduit.

13. The snap-action valve assembly of claim 12 further comprising:

a tension spring having a helical main body disposed between first and second hook ends, said first hook end of said tension spring being retained on said spring attachment arm of said shaft and said second hook end of said tension spring being retained on said anchor post, said tension spring biasing said valve flap to said closed position.

14. A snap-action valve assembly for an exhaust system comprising:

a first conduit extending along a central axis to define an exhaust passageway therein;

a valve flap disposed within said exhaust passageway for controlling exhaust flow through said exhaust passageway, said valve flap extending in a valve flap plane, said valve flap including a first arcuate edge;

a pad carried on said valve flap including a body portion and an end portion that extends over said first arcuate edge of said valve flap;

a shaft supporting said valve flap in said exhaust passageway for rotation between a closed position and an open position, said end portion of said pad contacting an inside surface of said first conduit when said valve flap is in said closed position;

said valve flap including a resilient tongue disposed between said valve flap and said body portion of said pad that is angled up and is spaced away from said first arcuate edge of said valve flap;

said pad being attached to and supported by said resilient tongue; and

said resilient tongue extending from said valve flap at a first angle relative to said valve flap plane that changes as said resilient tongue deflects in response to said end portion of said pad contacting said inside surface of said first conduit when said valve flap pivots to said closed position.

15. The snap-action valve assembly of claim 14 , wherein said valve flap includes a first side that faces upstream in said exhaust passageway, a second side that faces downstream in said exhaust passageway, a first valve flap ear disposed to one side of said shaft, and a second valve flap ear disposed to an opposite side of said shaft relative to said first valve flap ear, said first valve flap ear having a greater surface area than said second valve flap ear.

16. The snap-action valve assembly of claim 15 , wherein said resilient tongue is attached to said first side of said valve flap and extends from said first valve flap ear at first angle relative to said valve flap plane such that said resilient tongue deflects towards said first arcuate edge of said valve flap as said end portion of said pad makes contact with said inside surface of said first conduit to dampen vibration related harmonics and excessive valve flutter.

17. The snap-action valve assembly of claim 15 , wherein said resilient tongue is attached to said second side of said valve flap and extends from said second valve flap ear at said first angle relative to said valve flap plane such that said resilient tongue deflects away from said valve flap plane as said end portion of said pad makes contact with said inside surface of said first conduit to dampen vibration related harmonics and excessive valve flutter.

18. The snap-action valve assembly of claim 15 , wherein said shaft is mounted off-center in said exhaust passageway such that a pivot axis is spaced from said central axis of said first conduit.

19. A snap-action valve assembly for an exhaust system comprising:

a first conduit extending along a central axis to define an exhaust passageway therein;

a valve flap disposed within said first conduit for controlling exhaust flow through said exhaust passageway;

a shaft supporting said valve flap in said exhaust passageway for rotation about a pivot axis between a closed position and an open position;

said valve flap extending in a valve flap plane, said valve flap including a first arcuate edge and a pair of side edges;

said valve flap having an first side and a second side opposite said first side;

a pad including a body portion that is attached to said first side of said valve flap and an end portion that extends over said first arcuate edge;

said end portion of said pad contacting an inside surface of said first conduit when said valve flap is in said closed position; and

said pad including at least one side wing extending from said body portion of said pad that wraps around at least one of said side edges of said valve flap to contact said second side of said valve flap, said at least one side wing being sized for contact with said inside surface of said first conduit when said valve flap is in said open position to dampen vibration related harmonics and valve flap flutter.

20. The snap-action valve assembly of claim 19 , wherein said pad includes first and second side wings that extend in opposite directions from said body portion of said pad, wrap around said side edges of said valve flap, and extend at least partially across said second side of said valve flap.