U.S. patent application number 13/343963 was filed with the patent office on 2012-07-19 for exhaust assembly for use with a combustion engine.
Invention is credited to Mario Mueller, Frank Johan Hubert Nottelman, Sjoerd Henricus Anna Ottenheim.
Application Number | 20120181106 13/343963 |
Document ID | / |
Family ID | 43878064 |
Filed Date | 2012-07-19 |
United States Patent
Application |
20120181106 |
Kind Code |
A1 |
Nottelman; Frank Johan Hubert ;
et al. |
July 19, 2012 |
Exhaust Assembly For Use With A Combustion Engine
Abstract
An exhaust assembly having a first combustion gas flow route, a
second combustion flow route, and a valve. The first combustion gas
flow route includes at least one sound damper. The at least one
sound damper is a high-frequency damper adapted to dampen primarily
higher frequencies of the frequency spectrum being contained in the
combustion gas. The second combustion gas flow route has
substantially no sound damping, so that the first and second
combustion gas flow routes have different damping characteristics.
The valve is operable selectively by an operator and adapted to
selectively divide an approximately constant stream of combustion
gases from an engine selectively over the first and second
combustion gas flow routes, irrespective of the volume of the
combustion gase.
Inventors: |
Nottelman; Frank Johan Hubert;
(Belfeld, NL) ; Ottenheim; Sjoerd Henricus Anna;
(Reuver, NL) ; Mueller; Mario; (Stammheim,
DE) |
Family ID: |
43878064 |
Appl. No.: |
13/343963 |
Filed: |
January 5, 2012 |
Current U.S.
Class: |
181/228 |
Current CPC
Class: |
F01N 2470/02 20130101;
F01N 2590/04 20130101; F01N 2240/36 20130101; F01N 1/10 20130101;
F01N 1/168 20130101; F01N 1/24 20130101; F01N 1/166 20130101; F01N
1/006 20130101 |
Class at
Publication: |
181/228 |
International
Class: |
F01N 13/08 20100101
F01N013/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 14, 2011 |
DE |
20 2011 001 554.8 |
Claims
1. An exhaust assembly for use with a combustion engine, said
exhaust assembly comprising; a first combustion gas flow route,
wherein the first combustion gas flow route includes at least one
sound damper, said at least one sound damper being a high-frequency
damper, wherein the high-frequency damper is adapted to dampen
primarily higher frequencies of the frequency spectrum being
contained in the combustion gas; a second combustion gas flow
route, wherein the second combustion gas flow route has
substantially no sound damping, so that the first and second
combustion gas flow routes have different damping characteristics;
and a valve operable selectively by an operator during use of the
exhaust assembly with a combustion engine being coupled thereto,
and wherein the valve is adapted to selectively divide an
approximately constant stream of combustion gases from an engine
over the first and second combustion gas flow routes, irrespective
of the volume of the combustion gases.
2. The exhaust assembly according to claim 1, in which the
high-frequency damper is a closed sound-trapping chamber which is
in communication with the first combustion gas flow route via sound
passage openings, wherein the sound passage openings are not part
of the first combustion gas flow route and substantially are not
passed through by the combustion gas.
3. The exhaust assembly according to claim 2, in which the
sound-trapping chamber is filled with a damping material.
4. The exhaust assembly according to claims 1, in which the exhaust
assembly has a gas-tight housing and a perforated inner tube being
placed at a distance therefrom, wherein the housing at one side
thereof is closed around the inner tube, and wherein the valve is
located for complete or partial closing of the inner tube, and
wherein when the valve is opened, the second combustion gas flow
route uninterruptedly extends through the inner tube in order to
form a free flow route, while when the valve is closed, the first
combustion gas flow route extends via the inner tube and
perforation openings formed therein through a bypass duct between
the inner tube and the housing, and wherein a cylindrical
sound-trapping chamber is arranged in the housing which is in
communication with the first combustion gas flow route via the
sound passage openings.
5. The exhaust assembly according to claim 2, in which the
cylindrical sound-trapping chamber is formed by a gas-tight outer
housing wall and a perforated inner sound passage wall.
6. The exhaust assembly according to claim 5, in which a deflection
element is provided in the first combustion gas flow route, by
means of which the flow route of the combustion gases is extended
along the perforated inner sound passage wall of the sound-trapping
chamber.
7. The exhaust assembly according to claim 2, in which additional
sound passage openings are also provided between the second
combustion gas flow route and the sound-trapping chamber.
8. The exhaust assembly according to claim 2, in which additional
sound passage openings are also provided between a common flow
route, which is jointly formed by the first and the second
combustion gas flow route, and the sound-trapping chamber.
9. The exhaust assembly according to claim 4, in which the inner
tube has sound passage openings which are not part of the first
combustion gas flow route and substantially are not passed through
by the combustion gas.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims the benefit of German Patent
Application No. 10 2011 001 554.8 filed Jan. 14, 2011, which is
fully incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
FIELD OF THE INVENTION
[0003] The present invention relates to an exhaust assembly for use
with a combustion engine. Such an exhaust assembly is known from
document DE 697 02 447 T2.
BACKGROUND OF THE INVENTION
[0004] In the known exhaust assembly two separate combustion gas
flow routes can be controlled to change the damping characteristic
of the exhaust assembly. In this context, in particular a rotatably
mounted valve can be employed as the control means, making it
possible to selectively block or open the combustion gas flow
routes in order to change the gas distribution in the two
combustion gas flow routes. Thereby, the exhaust assembly is
characterized in that the two combustion gas flow routes have a
different damping characteristic. The first combustion gas flow
route is characterized by damping means enabling muffling of the
combustion gases being discharged by the exhaust assembly. The
second combustion gas flow route, by contrast, is characterized in
that no damping means at all or else only attenuated damping means
are provided, so that combustion gases being discharged along the
second combustion gas flow route are not muffled at all or are
muffled in an attenuated fashion.
[0005] As a result, by controlling the control means, the user is
provided with the option to selectively change the damping
characteristic of the exhaust assembly. When the combustion gases
are routed via the first combustion gas flow route, the combustion
gases are muffled and noise emissions are correspondingly reduced.
If the combustion gases, by contrast, are routed via the second
combustion gas flow route, the combustion gases are discharged
without being muffled while enabling a correspondingly enhanced
performance of the combustion engine, and cause a higher noise
level.
[0006] Said known exhaust assemblies are employed in particular in
large-volume combustion engines of motorcycles. The users of such
motorcycles preferably desire to have a maximum low-frequency noise
characteristic reminiscent of a bubbling sound. Tests have now
shown that the control means being required in exhaust assemblies
of this generic type, which are frequently designed in the type of
a valve flap, give rise to the generation of undesirable relatively
high-frequency noise, whereas the desirable low-frequency parts are
filtered out by the damping means in the first combustion gas flow
route. As a result, the known exhaust assemblies of the control
means for changing the damping characteristic thus have a noise
characteristic which is widely criticized in respect of the
frequency distribution.
SUMMARY OF THE INVENTION
[0007] Thus, it is an object of the present invention to suggest a
novel exhaust assembly for use with a combustion engine, which has
a damping characteristic that can be selectively changed while
providing an enhanced noise characteristic.
[0008] This object is attained in one embodiment by an exhaust
assembly having a first combustion gas flow route, a second
combustion flow route, and a valve. The first combustion gas flow
route includes at least one sound damper. The at least one sound
damper is a high-frequency damper adapted to dampen primarily
higher frequencies of the frequency spectrum being contained in the
combustion gas. The second combustion gas flow route has
substantially no sound damping, so that the first and second
combustion gas flow routes have different damping characteristics.
The valve is operable selectively by an operator and adapted to
selectively divide an approximately constant stream of combustion
gases from an engine over the first and second combustion gas flow
routes, irrespective of the volume of the combustion gase.
[0009] The inventive exhaust assembly is based on the fundamental
idea that the damping means of the first combustion gas flow route
comprise a high-frequency damper, wherein said high-frequency
damper is adapted to dampen primarily higher frequencies of the
frequency spectrum being contained in the combustion gas. The term
"high-frequency damper" thus is supposed to mean that the
high-frequency damper is suitable for damping the relatively higher
frequencies of the frequency spectrum being contained in the
combustion gas. In fact it does not refer to the damping of
high-frequency oscillations of the electromagnetic wave spectrum.
The damping of said higher frequencies of the frequency spectrum
being contained in the combustion gas significantly enhances the
noise characteristic of the exhaust assembly, since the undesirable
higher frequencies are eliminated, respectively reduced. By
contrast, the high-frequency damper has no significant impact on
the desirable lower frequencies of the frequency spectrum being
contained in the combustion gas. The constructional design of the
high-frequency damper of the inventive exhaust assembly is
basically optional. However, here the high-frequency damper is
preferably designed in the type of a closed sound-trapping chamber
which is in communication with the first combustion gas flow route
via sound passage openings. Said sound passage openings here are
not part of the first combustion gas flow route and substantially
are not passed through by the combustion gas. Instead, only the
sound waves pass through the sound passage openings and are damped
selectively in the closed sound-trapping chamber to the effect that
primarily higher frequencies are eliminated or reduced. By
contrast, the desirable lower frequencies are not impaired at all
or else only very slightly by the closed sound-trapping
chamber.
[0010] In order to enhance the desirable damping effect for damping
the higher frequencies of the frequency spectrum being contained in
the combustion gas, the sound-trapping chamber can be filled with a
damping material, for instance damping wool.
[0011] A particularly simple and inexpensively producible
embodiment of the inventive exhaust assembly can be obtained if the
exhaust assembly has a gas-tight housing and a perforated inner
tube which is placed at a distance therefrom. In this regard, the
housing at one side thereof is closed around the inner tube and is
connected to a combustion gas supply pipe via connecting means.
Furthermore, valve means for completely or partially closing the
inner tube are provided at a distance from the connecting means.
When the valve means are opened, the combustion gas is enabled to
uninterruptedly pass through the inner tube into the environment,
so that the inner tube forms the second combustion gas flow route
when the valve means are opened. When the valve means are closed,
the combustion gas is prevented from being discharged through the
inner tube and instead is deflected at the valve means. As a
result, the combustion gas then initially passes through the inner
tube and through perforation openings formed therein into a bypass
which comprises the inner tube in a cylindrical fashion and is part
of the first combustion gas flow route. From said bypass, the
combustion gas is then enabled to flow back again through
perforation openings into the inner tube, in order to be discharged
therefrom into the environment, or else the combustion gas is
directly discharged from the bypass into the environment. In the
bypass being located downstream of the perforation openings of the
inner tube, it is possible to optionally install damping means. On
the inside of the housing, which as such forms the outside of the
bypass for the first combustion gas flow route, it is possible to
arrange sound passage openings of the cylindrically designed
sound-trapping chamber. As a result, the combustion gas is then
discharged through the bypass and thereby passes through the sound
passage openings of the sound-trapping chamber which surrounds said
bypass in a cylindrical fashion.
[0012] In the exhaust assembly having the inner tube and the valve
means, it is particularly advantageous if the cylindrical
sound-trapping chamber is formed by a gas-tight outer housing wall
and a perforated inner sound passage wall. The perforations in the
sound passage wall thereby are not required to be formed
completely, but partial perforation of the sound passage wall in
many cases is already sufficient.
[0013] In order to enhance the desirable damping effect for damping
the higher frequencies of the frequency spectrum being contained in
the combustion gas, according to a preferred alternative
embodiment, provision can be made for a deflection element in the
first combustion gas flow route, by means of which the flow route
of the combustion gases along the perforated inner sound passage
wall of the sound-trapping chamber is extended. By means of said
extended flow path along the sound passage wall of the
sound-trapping chamber, a correspondingly larger part of the sound
waves is passed through the sound passage walls and is damped to a
correspondingly higher extent.
[0014] In order to be able to eliminate, respectively reduce, the
undesirable higher frequencies of the frequency spectrum being
contained in the combustion gas even when said frequencies are
produced during the discharge along the second combustion gas flow
route, additional sound passage openings can also be provided
between the second combustion gas flow route and the sound-trapping
chamber. As a consequence, the sound-trapping chamber is capable of
damping in combination the higher frequencies of the frequency
spectrum being contained in the combustion gas both in the first
combustion gas flow route and in the second combustion gas flow
route.
[0015] In order to realize the combined damping of the higher
frequencies both in the second combustion gas flow route and in the
first combustion gas flow route, the additional sound passage
openings can also be arranged in the common flow route which is
jointly formed by the first and the second combustion gas flow
route.
[0016] If an embodiment of the exhaust assembly is used which has
an inner tube, said inner tube preferably can also have sound
passage openings which are not part of the first combustion flow
route and which substantially are not passed through by the
combustion gas.
[0017] Two embodiments of the inventive exhaust assembly are
schematically illustrated in the drawings and will be explained
hereinafter by way of example.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In the drawings:
[0019] FIG. 1 shows a first embodiment of an inventive exhaust
assembly in a longitudinal cross-sectional view;
[0020] FIG. 2 shows a second embodiment of an inventive exhaust
assembly in a longitudinal cross-sectional view.
DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS
[0021] FIG. 1 shows a first embodiment 01 of an inventive exhaust
assembly which is connected to a combustion engine (not shown) via
a combustion gas supply pipe 02. The exhaust assembly 01 is
substantially composed of an inner tube 03, a gas-tight housing 04
and valve means 05. By swiveling of the valve means 05, the
cross-section of the inner tube 03 can be opened and closed in an
operator-controlled fashion. When the valve means 05 are opened,
the combustion gas flowing from the combustion gas supply pipe 02
into the exhaust assembly is enabled to flow through the inner tube
03 into the environment without any significant damping and without
any interruption. Said undamped and uninterrupted flow route
through the inner tube 03 forms the second combustion gas flow
route within the meaning of the present invention.
[0022] When the valve means 05 are closed, as is exemplarily shown
in FIG. 1, the flow route is interrupted by the inner tube 03 and
the combustion gas flows through openings 06 into a cylindrical
bypass duct 07. At the end of the bypass duct 07, the combustion
gases then again flow back through openings 08 into the inner tube
03 and from there into the environment. This corresponds to the
first combustion gas flow route within the meaning of the present
invention and is schematically illustrated by the flow arrows
09.
[0023] The bypass duct 07 on the outside is limited by a perforated
inner sound passage wall 10 which has a plurality of sound passage
openings. By means of said sound passage openings in the sound
passage wall 10, the bypass duct 07 of the first combustion gas
flow route is connected to a cylindrical sound-trapping chamber 11
which is formed between the gas-tight outer housing wall 04 and the
perforated inner sound passage wall 10. The higher frequencies
generated in the bypass duct 07 of the first combustion gas flow
route are strongly damped when passing through the sound passage
openings in the sound passage wall 10. Damping wool 12, which is
shown in FIG. 1 using dashed lines, is filled into the
sound-trapping chamber 11 for enhancing the damping effect. The
perforation of the sound passage wall 10 continues at the
transition zone to the inner tube 03 so that the inner tube 03 also
features the only schematically illustrated sound passage openings
13. By means of the sound passage openings 13 in the inner tube 03,
the higher frequencies of the frequency spectrum being contained in
the combustion gas can also be damped when the valve means 05 are
opened.
[0024] FIG. 2 shows a second embodiment 14 of an inventive exhaust
assembly which in turn has a combustion gas supply pipe 02 for
supplying the combustion gases from a combustion engine. The
exhaust assembly 14 is also substantially composed of an inner tube
15, a housing wall 16 and valve means 17. When the valve means 17
are opened, the combustion gas is enabled to uninterruptedly flow
out of the combustion gas supply pipe 02 into the environment. Due
to the missing damping effect, enhanced efficiency is attained
while increased noise emissions are caused. When the valve means 17
are closed, the combustion gases flow through openings 18 into a
bypass duct 19, wherein the combustion gases are deflected into the
opposite direction at a deflection element 20. At the end of the
bypass duct 19, the combustion gases then flow through openings 21
and 22 back into the inner tube 15 and from there into the
environment. The bypass duct 19 in the exhaust assembly 14 in turn
is included in a cylindrical sound-trapping chamber 23, the inner
sound passage wall 24 thereof being perforated with a plurality of
only schematically illustrated sound passage openings 25. The sound
waves passing through the sound passage openings 25 out of the
bypass duct 19 into the sound-trapping chamber 23 are strongly
damped in terms of the higher frequencies being contained in the
frequency spectrum, thus enabling the desirable damping effect. By
means of the deflection element 20 the flow route of the combustion
gases along the sound passage wall 24 having the sound passage
openings 25 is strongly extended and the damping effect is
correspondingly enhanced. The damping wool 26 in the sound-trapping
chamber 23 again is shown in FIG. 2 using dashed lines. The front
part of the inner tube 15 can equally be perforated with sound
passage openings 25 upstream of the openings 18 in order to enable
the passage of sound waves when the valve means 17 are opened.
* * * * *