U.S. patent application number 11/544201 was filed with the patent office on 2007-05-17 for exhaust silencer.
Invention is credited to Jason M. Sicotte.
Application Number | 20070107981 11/544201 |
Document ID | / |
Family ID | 38039590 |
Filed Date | 2007-05-17 |
United States Patent
Application |
20070107981 |
Kind Code |
A1 |
Sicotte; Jason M. |
May 17, 2007 |
Exhaust silencer
Abstract
An exhaust silencer includes a flow pipe supported in a housing.
A space is defined between the flow pipe and the housing. At least
one movable flap is located in the space and is resiliently biased
to a closed position and movable by exhaust gas pressure from said
closed position to an opened position. The at least one flap
provides less restriction to exhaust gas flow through the space in
the opened position as compared to the closed position. The one or
more flaps are pivotably supported on a spring-biased hinge
assembly or are provided as part of a resiliently deformable baffle
plate that uncovers flow apertures under force of exhaust pressure.
The baffle plate is selectively removable by an end-user to allow
for maximum exhaust flow when desired. The flow pipe can be omitted
in a base plate only version.
Inventors: |
Sicotte; Jason M.; (Bristol,
CT) |
Correspondence
Address: |
FAY SHARPE LLP
1100 SUPERIOR AVENUE, SEVENTH FLOOR
CLEVELAND
OH
44114
US
|
Family ID: |
38039590 |
Appl. No.: |
11/544201 |
Filed: |
October 6, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60724460 |
Oct 7, 2005 |
|
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|
Current U.S.
Class: |
181/237 |
Current CPC
Class: |
F01N 1/165 20130101;
F01N 1/166 20130101; F01N 13/20 20130101; F01N 1/18 20130101; F01N
1/22 20130101 |
Class at
Publication: |
181/237 |
International
Class: |
F01N 1/16 20060101
F01N001/16 |
Claims
1. An exhaust silencer comprising: a housing; a flow pipe supported
in said housing; a space defined between said flow pipe and said
housing; at least one movable flap located in said space and
resiliently biased to a closed position and movable by exhaust gas
pressure from said closed position to an opened position, wherein
said at least one flap provides less restriction to exhaust gas
flow through said space in said opened position as compared to said
closed position.
2. The exhaust silencer as set forth in claim 1, wherein said at
least one flap pivots between said closed and opened positions.
3. The exhaust silencer as set forth in claim 2, wherein said at
least one flap comprises first and second separate flaps that each
pivot between said closed and opened positions.
4. The exhaust silencer as set forth in claim 3, further comprising
at least one spring engaged with said first and second flaps to
bias said first and second flaps to their respective closed
positions.
5. The exhaust silencer as set forth in claim 4, further comprising
first and second hinges that extend between said flow pipe and said
housing, wherein said first and second flaps are each connected to
both said first and second hinges, and wherein said at least one
spring is a torsion spring connected to one of said first and
second hinges.
6. The exhaust silencer as set forth in claim 5, wherein said at
least one spring comprises first and second springs respectively
connected to said first and second hinges, wherein each of said
first and second springs is engaged with both of said first and
second flaps.
7. The exhaust silencer as set forth in claim 6, further comprising
first and second stops located between said housing and said flow
pipe, said first and second stops abutting said first and second
flaps, respectively, when said first and second flaps are in their
respective closed positions.
8. The exhaust silencer as set forth in claim 7, wherein said first
and second flaps define a 180 degree angle therebetween when the
first and second flaps moved to their closed positions, and wherein
said first and second flaps define therebetween an angle of less
than 180 degrees when the first and second flaps are moved their
respective opened positions.
9. The exhaust silencer as set forth in claim 7, wherein said flow
pipe is located centrally in said housing so that said space
defined between said housing and said flow pipe is an annular space
that encircles said flow pipe.
10. The exhaust silencer as set forth in claim 9, wherein said
first and second hinges are arranged in diametrically opposed
locations relative to each other.
11. The exhaust silencer as set forth in claim 10, wherein said
flow pipe defines an unobstructed flow path from an open upstream
end to an open downstream end thereof.
12. The exhaust silencer as set forth in claim 1, wherein said at
least one flap is defined as part of a flexible metal baffle that
is secured in said space, wherein said at least one flap moves from
said closed position to said opened position by resilient
deformation of said metal baffle under force of exhaust gas
pressure in said space, and wherein said at least one flap
resiliently moves from said opened position to said closed position
when said exhaust gas pressure in said space subsides.
13. The exhaust silencer as set forth in claim 12, wherein said at
least one flap comprises first and second flaps.
14. The exhaust silencer as set forth in claim 13, wherein said
first and second flaps are defined by said metal baffle as a
one-piece construction.
15. The exhaust silencer as set forth in claim 12, further
comprising a base plate secured in said space between said flow
pipe and said housing, said base plate defining at least one flow
aperture, wherein said metal baffle is secured to said base plate
and occludes said at least one flow aperture when in said closed
position and moves away from said at least one flow aperture when
in said opened position.
16. The exhaust silencer as set forth in claim 15, wherein said
metal baffle is secured to said base plate by at least one
removable fastener that allow for selective separation of said
baffle from said base plate for maximum exhaust flow.
17. The exhaust silencer as set forth in claim 16, wherein said
base plate comprises an outer flange that is secured to said
housing and comprises a pipe support aperture through which said
flow pipe extends, and wherein said baffle comprises an opening
through which said flow pipe extends.
18. The exhaust silencer as set forth in claim 12, wherein said
metal baffle comprises a flexible metal sheet.
19. The exhaust silencer as set forth in claim 1, wherein said at
least one flap is defined by a stack of at least two flexible metal
baffles that are secured in said space, wherein said at least one
flap moves from said closed position to said opened position by
resilient deformation of said stack of metal baffles under force of
exhaust gas pressure in said space, and wherein said at least one
flap resiliently moves from said opened position to said closed
position by relative flattening of said stack of metal baffles when
said exhaust gas pressure in said space subsides.
20. The exhaust silencer as set forth in claim 20, further
comprising a base plate secured in said space between said flow
pipe and said housing, said base plate defining at least one flow
aperture, wherein said stack of metal baffles is secured to said
base plate and occludes said at least one flow aperture when in
said closed position and moves away from said at least one flow
aperture when in said opened position.
21. An exhaust silencer comprising: a housing; a base plate secured
in the housing, the base plate comprising at least one main flow
opening and at least one secondary flow opening; at least one
flexible metal baffle secured to the base plate and normally
resiliently biased to a closed position where it covers the
secondary flow aperture, wherein said baffle is resiliently movable
by exhaust gas pressure from said closed position to an opened
position where it moves away from the at least one secondary flow
opening to allow exhaust gas flow through the at least one
secondary flow opening.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from and benefit of the
filing date of U.S. provisional application Ser. No. 60/724,460
filed Oct. 7, 2005, and said provisional application is hereby
incorporated by reference into the present specification.
BACKGROUND
[0002] Silencers for automobile exhaust systems are known. One type
of silencer is known as an active silencer due to its capacity to
adjust in response to pressure of exhaust gases in the system. As
such, at low engine revolutions per minute (RPM) with
correspondingly low exhaust pressure, the silencer remains
substantially closed to increase exhaust backpressure and reduce
noise, while increase in engine RPM causes a corresponding increase
in exhaust gas pressure which, in turn, is used to open the
silencer against the closing force of a biasing spring to reduce
backpressure which causes an increase in exhaust noise and engine
power. While known active silencers are superior to passive
silencers, which merely restrict exhaust flow by constant amount,
known active silencers have also been deemed deficient for
complexity, cost, insufficient backpressure reduction when opened,
reliability and other reasons. As such, a need has been identified
for a new and improved active exhaust silencer.
SUMMARY
[0003] In accordance with one aspect of the present invention, an
exhaust silencer includes a housing and a flow pipe supported in
the housing. A space defined between the flow pipe and the housing.
At least one movable flap is located in the space and is
resiliently biased to a closed position and movable by exhaust gas
pressure from the closed position to an opened position. The flap
provides less restriction to exhaust gas flow through the space in
the opened position as compared to the closed position.
[0004] In accordance with another aspect of the present invention,
and exhaust silencer includes a housing and a base plate secured in
the housing. The base plate defines at least one main flow opening
and at least one secondary flow opening. At least one flexible
metal baffle is secured to the base plate and is normally
resiliently biased to a closed position where it covers the
secondary flow aperture. The baffle is resiliently movable by
exhaust gas pressure from its closed position to an opened position
where it moves away from the secondary flow opening(s) to allow
exhaust gas flow therethrough.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a cross-sectional view of an exhaust silencer
formed in accordance with the present development;
[0006] FIG. 2 is an end view of the exhaust silencer taken along
view line 2-2 of FIG. 1 and shows the silencer in its closed state
(note that in FIG. 2, the exhaust silencer is not sectioned as in
FIG. 1);
[0007] FIG. 3 is an end view that corresponds to FIG. 2, but shows
the exhaust silencer in its opened state;
[0008] FIG. 4 is an end view similar to FIG. 2, but shows an
exhaust silencer formed in accordance with an alternative
embodiment (a portion of the baffle is broken away to reveal an
underlying baffle base plate);
[0009] FIG. 5 is a sectional view of the exhaust silencer of FIG.
4, as taken along line 5-5 of FIG. 4;
[0010] FIG. 6 is a sectional view that is similar to FIG. 5, but
shows an alternative embodiment of an exhaust silencer formed in
accordance with the present development.
[0011] FIG. 7 is a sectional view that is similar to FIG. 6, but
shows another alternative embodiment of an exhaust silencer formed
in accordance with the present development.
DETAILED DESCRIPTION
[0012] FIGS. 1-3 illustrate an exhaust silencer ES formed in
accordance with a first embodiment of the present development for
use in silencing/tuning the exhaust of an internal combustion
engine such as used to propel a vehicle such as an automobile,
boat, etc. or for some other purpose.
[0013] As illustrated herein, the silencer ES is intended to be
retro-fitted into an existing exhaust tailpipe T using one or more
fasteners F1 such as a bolt, rivet, screw, etc., or by other means
such as welding, friction-fit or the like to secure the silencer to
the tailpipe T. In particular, the exhaust silencer ES comprises an
outer housing tube H that is fitted into the tailpipe T, and the
fasteners F1 or other means are used to fixedly secure the housing
tube H relative to the tailpipe T. If necessary and/or desired, a
spacer or gasket K can be used to surround the housing tube H to
fill any space defined between the tailpipe T and housing tube H.
In some cases, such as when the silencer ES is supplied as original
equipment, the tailpipe T, itself, provides the housing tube H, and
the fasteners F1 are not needed.
[0014] At least one open flow pipe P is located, preferably
concentrically, in the housing tube H and secured therein by
rivets, bolts, screws and/or other fasteners F2 (FIG. 1) that
engage the housing tube H and open flow pipe P. This open flow pipe
P has an upstream end P1 and a downstream end P2 and allows
free-flow of exhaust gases therethrough from the upstream end P1 to
the downstream end P2 so that exhaust gases can flow from an
upstream position in the tailpipe T toward the outlet O of the
tailpipe T as indicated by arrow A1 in FIG. 1.
[0015] An annular space B is defined between the pipe P and the
housing H. First and second flow-control flaps C1,C2 are located in
the annular space B, near an outer end thereof. These flaps C1,C2
move between a closed position (FIGS. 1 and 2) where they are
arranged at a 180 degree angle relative to each other or are
otherwise arranged to substantially block the flow of exhaust gases
through the annular space B from an upstream location in the
tailpipe T to the tailpipe outlet O (see arrows A2), and an opened
position (FIG. 3 and phantom lines of FIG. 1) where they define an
included angle .THETA. of less than 180 degree or are otherwise
arranged so as to allow flow of exhaust gases through the annular
space B from an upstream location in the tailpipe T to the tailpipe
outlet O (see arrows A3). The flaps C1,C2 are located near the
downstream/outer end P2 of the pipe P so that the pipe P does not
interfere with pivoting movement of the flaps C1,C2.
[0016] As is easily seen in FIG. 3, the flow-control flaps C1,C2
are pivotally connected to the housing tube H and the open flow
pipe P. In particular, first and second hinges G1,G2 defined by
pins or the like and extend between the housing tube and pipe P in
diametrically opposed locations, and the flaps C1,C2 are each
pivotally connected to both hinges G1,G2. At least one of the
hinges G1,G2 comprises a torsion spring N or the like that includes
feet N1,N2 that are engaged respectively with the flaps C1,C2 to
bias the flaps C1,C2 to their closed positions (FIG. 2) where they
obstruct the flow of exhaust gases through the annular space B (as
shown, each hinge G1,G2 comprises a separate spring N). The
spring(s) N is (are) selected so that the flaps C1,C2 are able to
pivot against the spring(s) N as shown by arrows A4 when the
exhaust gas pressure in the annular space B exceeds a select
threshold, which will vary depending upon the desired performance
characteristics and the particular vehicle or other application. In
one embodiment, the flaps are intended to stay closed during idle
of an automobile, to open slightly (i.e., move 10 degrees or so
from vertical) during normal vehicle acceleration, and open
substantially (i.e., move at least 30 degrees from vertical) during
hard acceleration.
[0017] When the exhaust gas pressure in the annular space B
subsides, the springs N1,N2 return the flaps C1,C2 toward and/or
fully to their closed positions. Stops M1,M2 are provided and
engage the flaps C1,C2, respectively, when the flaps are closed to
prevent movement of the flaps C1,C2 beyond their closed positions
under force of springs N1,N2. As shown, the stops M1,M2 are defined
by indented portions of the housing tube H, but can be defined by
rivets, tabs, screws or other suitable fixed member that extends
into the annular space B.
[0018] Those of ordinary skill in the art will recognize that when
the flaps C1,C2 are closed, exhaust gas flow and noise are
restricted owing to the fact that the only path for the exhaust
gases to flow to the tailpipe outlet O is via pipe P (except for
any leakage around flaps C1,C2). When the flaps C1,C2 open under
exhaust pressure, the exhaust gas flow and engine performance and
noise increase, because the exhaust gases are able to flow to the
tailpipe outlet O through the pipe P and also through the annular
space B. As such, the exhaust silencer ES provides a self-adjusting
capability that is responsive to exhaust gas pressure that varies
with driving habits or other causes of variations in exhaust gas
pressure.
[0019] Except for the optional gasket K, the components of the
exhaust silencer are preferably defined from a metal such as steel
or stainless steel using grades and alloys that are known in the
exhaust arts. The springs N1,N2 are preferably metal and defined
from suitable spring wire such as (by way of example only)
stainless steel, Inconel, or other metal with sufficient resistance
to elevated temperature creep and fatigue.
[0020] FIGS. 4 and 5 illustrate an alternative exhaust silencer ES'
formed in accordance with the present development. The silencer ES'
is intended for the same application and use and to perform the
same function as the silencer ES, but includes a different
silencing mechanism. Components of the silencer ES' that correspond
to components of the silencer ES are labeled with reference
characters that correspond to those used in FIGS. 1-3, but include
a primed (') suffix.
[0021] The silencer ES' is intended to be retro-fitted into an
existing exhaust tailpipe T' using one or more fasteners F1' such
as a bolt, rivet, screw, etc., or by other means such as welding,
friction-fit or the like that engage the tailpipe T' and housing
tube H'. In particular, the exhaust silencer ES' comprises an outer
housing tube H' that is fitted into the tailpipe T', and the
fasteners F1' or other means are used to fixedly secure the housing
tube H' relative to the tailpipe T'. If necessary and/or desired, a
gasket K' can be used to surround the housing tube H' to fill any
space defined between the tailpipe T' and housing tube H'. In some
cases, such as when the silencer ES' is supplied as original
equipment, the tailpipe T', itself, provides the housing tube H',
and the fasteners F1' are not needed.
[0022] At least one open flow pipe P' is located, preferably
concentrically, in the housing tube H'. The pipe P' is secured in
this position by one or more rivets, bolts, screws and/or other
fasteners F2' that engage the housing tube H' and open flow pipe
P'. This open flow pipe P' has an open upstream end P1' and an open
downstream end P2' so as to allow free-flow of exhaust gases
therethrough from an upstream position in the tailpipe T' toward
the outlet O' of the tailpipe T' as indicated by arrow A1'. An
annular space B' is defined between the flow pipe P' and the
housing tube H'.
[0023] A baffle base plate D' is closely fitted in the housing tube
H' and is secured in this position. As shown, the baffle base plate
D' includes an outer flange DF' that is engaged by the fasteners
F1' or welding or the like to secure the baffle base plate D' in
its operative position in the housing tube H'. The baffle base
plate D' also defines a central pipe-support aperture DA' through
which the open flow pipe P' extends. An optional fastener F3' or a
spot weld, or other means is used to secure the pipe P' to the
baffle base plate D'. The baffle base plate D' defines one or more
flow apertures DE' that provide a path for exhaust gases to flow
from an upstream location in the tailpipe T', through the annular
space B' and through the base plate D' to the tailpipe outlet
O'.
[0024] To regulate the flow of exhaust gases through the flow
apertures DE' of the base plate D', at least one flexible baffle J'
is secured adjacent the downstream side of the base plate D'(facing
tailpipe outlet O'). The baffle J' is preferably defined by a
flexible metal sheet that includes an opening JO' through which the
flow pipe P' is loosely received. As shown, the baffle J' is
secured directly to the base plate D' by one or more rivets, screws
or other fasteners F4'. In some cases, the fasteners F4' are
preferably non-removable and in others, the fasteners F4' are
screws or other removable fasteners that allow a user to change
baffles J' or add (by stacking) additional baffles J' to control
exhaust flow. As is shown in FIG. 4 and in solid lines in FIG. 5,
the baffle J' has a natural flat shape when relaxed or in a free
state so that the baffle J' is in a closed position and covers the
flow apertures DE' of the base plate D' and inhibit or
substantially block flow of exhaust gases therethrough from the
annular space B' to the tailpipe outlet O'. The baffle J' is
flexible and bends under force of exhaust pressure in the annular
space B' to an opened position, as shown in broken lines in FIG. 5
and as indicated by arrows A5' where the flow apertures DE' are at
least partially uncovered by flaps C1',C2' of the baffle J' to
allow flow of exhaust gases through the annular space B from an
upstream location in the tailpipe T to the tailpipe outlet O (see
broken arrows A6' in FIG. 5). Those of ordinary skill in the art
will recognize that the first and second flaps C1',C2' of the
baffle J' correspond to the flaps C1,C2 of the exhaust silencer ES
illustrated in FIGS. 1-3. In the closed position, the flaps are
arranged at an angle of 180 degrees relative to each other and,
when opened, are moved inward toward each other against the natural
bias of the baffle J'. As shown herein, the flaps C1',C2' are part
of a one-piece baffle J'. Alternatively, the baffles C1',C2' can be
part of separate baffles J', each of which is secured to the base
plate D'.
[0025] The baffle J' is selected so that it bends to the opened
position to allow exhaust gas flow through the flow apertures DE'
when the exhaust gas pressure in the annular space B exceeds a
select threshold, which will vary depending upon the desired
performance characteristics and the particular vehicle or other
application. In one embodiment, the baffle J' is intended to stay
closed during idle of an automobile, to open slightly and partially
uncover the apertures DE' during normal vehicle acceleration, and
to open fully during hard acceleration to at least substantially
uncover the apertures DE'. When the exhaust pressure in the annular
space B' subsides, the baffle J' resiliently returns to its
normally closed position, which is a relatively flattened (not
necessarily completely flat) state relative to the opened
position.
[0026] Those of ordinary skill in the art will recognize that when
the baffle J' is closed, exhaust gas flow and noise are restricted
owing to the fact that the only path for the exhaust gases to flow
to the tailpipe outlet O' is via open pipe P' (except for some
leakage around the baffle base plate D' and/or leakage through flow
apertures DE'). When the baffle J' opens, the exhaust gas flow and
engine performance and noise increase, because the exhaust gases
are able to flow to the tailpipe outlet O' through both the pipe P'
and also through the annular space B' via apertures DE'. As such,
the exhaust silencer ES' provides a self-adjusting capability that
is responsive to exhaust gas pressure that varies with driving
habits or other causes of variations in exhaust gas pressure.
[0027] Except for the optional gasket K, which can be a heat/fire
resistant insulation material, components of the exhaust silencer
ES' are preferably defined from a metal such as steel or stainless
steel using grades and alloys that are known in the exhaust arts.
The baffle J' is preferably defined from metal such as (by way of
example only) stainless steel, Inconel, or other metal with
sufficient resistance to elevated temperature creep and fatigue,
having a thickness, e.g., in the range of 0.005 inches to 0.015
inches (the thickness is varied to control the exhaust pressure
required to flex the baffle J' to its opened position). If desired,
the user can selectively remove the baffle ' to allow full exhaust
flow under all conditions by removing screws F4'. Also, the baffle
J' can be changed by a user to control the opening pressure (by
replacing a baffle J' with another having different flexibility),
and multiple baffles J' (of same or varied thickness/flexibility)
can be stacked against the base plate D' if desired to increase the
pressure required to open the flow apertures DF'.
[0028] FIG. 6 is a sectional view that is similar to FIG. 5, but
shows an alternative embodiment of an exhaust silencer 2ES' formed
in accordance with the present development. The exhaust silencer
2ES' is identical to the silencer ES' except as shown and/or
described herein. Specifically, in the silencer 2ES', the base
plate 2D' includes only a single flow aperture DE'. One or more
baffles 2J' (two as shown in FIG. 6) are stacked adjacent each
other and secured to the base plate 2D' by on or more fasteners
F4', preferably located as shown, on an opposite side of the flow
pipe P' relative to the flow aperture DE', e.g., at a 180 degree
angle relative to the center of the flow aperture DE', or at least
spaced sufficiently far from the aperture(s) DE' so that the one or
more baffles 2J' can flex away from the base plate 2D' as shown.
Each baffle 23' is identical to the baffle J' disclosed above,
except for the location of the fastener F4'. The opening 2JO' of
each baffle 2J' loosely accommodates the outer end P2' of the flow
pipe P' so that the baffles 2J' can move relative to the flow pipe
as described and shown herein. FIG. 6 shows the baffles 2J' in the
flexed, opened position, spaced from flow aperture DE' to allow
exhaust flow through the flow aperture DE' as indicated by arrow
A6'. When exhaust pressure in the space B' subsides, the baffles
2J' will move naturally by their own resilient nature to a closed
position where they cover the flow aperture DE' to impede exhaust
flow through the space B', which closed position is a relatively
flattened (not necessarily completely flat) state for the baffles
2J' relative to their opened position. Using one or more like
baffles 2J', a user can adjust the exhaust pressure required to
open/close the baffle(s) 2J', which is desirable to adjust for
different horsepower engines, etc. Thus, for example, for a lower
horsepower engine, the user can choose to use a single baffle 2J'
that will more easily flex to the opened position, while two or
more baffles 2J' can be used for a higher horsepower engine so that
the baffles are more resistant to moving to the opened position,
requiring more exhaust pressure in the space B' to do so.
[0029] In another alternative embodiment 3ES' as shown in FIG. 7,
the flow pipe P' of FIGS. 4 and 5 or of FIG. 6 is not used. The
base plate aperture DA' is left open to define a main opening for
unrestricted exhaust flow A1' through the housing H' to the
tailpipe outlet O', while the base plate flow aperture(s) DE'
provide a secondary opening for exhaust flow only when the
baffle(s) 2J' (or J') are flexed from the closed to the opened
position by exhaust pressure as described herein. The opening 2JO'
in the baffle(s) 2J' is registered with the base plate aperture DA'
so that the baffle(s) 2J' do not block exhaust flow therethrough
(i.e., through the main opening) even when the baffle(s) 2J' are in
the closed position.
[0030] While considerable emphasis has been placed on the preferred
embodiments, it will be appreciated that other embodiments can be
made and that many changes can be made in the preferred embodiments
without departing from the principles of the invention, and it is
intended that the following claims be construed literally and/or
according to the doctrine of equivalents as broadly as
possible.
* * * * *