U.S. patent application number 11/467185 was filed with the patent office on 2007-03-01 for sound reduction system with sound reduction chamber.
This patent application is currently assigned to L&L Products, Inc.. Invention is credited to William J. Barz, Henry E. Richardson.
Application Number | 20070045042 11/467185 |
Document ID | / |
Family ID | 37802477 |
Filed Date | 2007-03-01 |
United States Patent
Application |
20070045042 |
Kind Code |
A1 |
Barz; William J. ; et
al. |
March 1, 2007 |
SOUND REDUCTION SYSTEM WITH SOUND REDUCTION CHAMBER
Abstract
A sound reduction system is provided. The system is preferably
designed to allow air or other fluid to flow through the system
while lessening the amount of sound flowing through the system.
Inventors: |
Barz; William J.; (St.
Clair, MI) ; Richardson; Henry E.; (Washington,
MI) |
Correspondence
Address: |
DOBRUSIN & THENNISCH PC
29 W LAWRENCE ST
SUITE 210
PONTIAC
MI
48342
US
|
Assignee: |
L&L Products, Inc.
Romeo
MI
|
Family ID: |
37802477 |
Appl. No.: |
11/467185 |
Filed: |
August 25, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60711101 |
Aug 25, 2005 |
|
|
|
Current U.S.
Class: |
181/250 ;
181/266; 181/276 |
Current CPC
Class: |
B60H 2001/006 20130101;
B60H 1/00564 20130101 |
Class at
Publication: |
181/250 ;
181/266; 181/276 |
International
Class: |
F01N 1/02 20060101
F01N001/02; F01N 1/08 20060101 F01N001/08 |
Claims
1. A system for reducing the passage of sound from a first location
to a second location, the system comprising; a structure of an
article of manufacture; and a housing adjacent the structure and
adjacent a fluid flow path, the housing defining a chamber,
wherein. i. the flow path allows fluid flow from the first location
to the second location; and ii. the flow path is adjacent the
chamber such that sound can enter the chamber, reflect of one or
more walls of the chamber and be canceled.
2. A system as in claim 1 wherein the housing is substantially
entirely formed of plastic.
3. A system as in claim 1 wherein the housing is attached to the
structure and includes an opening aligned with an opening of the
structure and seal provides sealing between the housing and the
structure at the opening of the housing, the structure or both.
4. A system as in claim 1 wherein the housing defines a first
opening and a second opening along the fluid flow path.
5. A system as in claim 1 wherein the housing defines a rear wall
that has a depth (D) from the entry location into the chamber of
0.106 meters.+-.30%.
6. A system as in claim 1 wherein the housing has rear walls at
multiple depths for canceling sound at various different
frequencies.
7. A system as in claim 1 wherein the chamber is adjacent to the
fluid flow path such that first sound from the external environment
enters the chamber, is reflected off of a rear wall of the chamber
and cancels other second sound entering the chamber such that the
first and second sound do not continue along the fluid flow path,
the second sound having a wavelength within 6 cm of the first
sound, the rear wall being a distance of within 4 cm of a 1/4 of
the wavelength of the first and/or second sound from a central area
of an opening that provides fluid communication to the passenger
compartment.
8. A system as in claim 1 wherein the structure is part of an
automotive vehicle.
9. A system as in claim 8 wherein the structure is a pillar of the
automotive vehicle.
10. A system for reducing the passage of sound from a first
location to a second location, the system comprising: a structure
of an automotive vehicle, the structure having one or more openings
for providing fluid communication between an internal cabin of an
automotive vehicle and an external environment surrounding the
vehicle; an housing associated with the structure of the automotive
vehicle, wherein: i. the housing substantially surrounds a chamber;
and ii. the housing includes one or more openings for providing
fluid communication between the internal cabin of the automotive
vehicle and the external environment surrounding the vehicle; and
iii. sound enters the housing through the one or more openings of
the housing and is reflected off one or more walls defining the
chamber thereby canceling at least a portion of the sound.
11. A system as in claim 10 wherein the housing is formed
substantially entirely of plastic.
12. A system as in claim 10 wherein the structure is a pillar of an
automotive vehicle.
13. A system as in claim 10 wherein the housing includes a first
opening in fluid communication with the chamber and a second
opening.
14. A system as in claim 13 wherein the chamber is located beside a
path from the first opening to the second opening.
15. A system as in claim 14 wherein the chamber is located closer
to a distal end of the housing relative to both the first and
second openings.
16. A system as in claim 10 wherein an annular seal extends about a
periphery of the housing.
17. A system as in claim 16 wherein the seal is formed of a heat
activatable material that foams and cures upon exposure to elevated
temperatures.
18. A system for reducing the passage of sound from a first
location to a second location, the system comprising: a structure
of an automotive vehicle, the structure having one or more openings
for providing fluid communication between an internal cabin of an
automotive vehicle and an external environment surrounding the
vehicle, wherein the structure of the automotive vehicle is a
pillar; an housing associated with the structure of the automotive
vehicle, wherein: i. the housing substantially surrounds a chamber;
and ii. the housing includes one or more openings for providing
fluid communication between the internal cabin of the automotive
vehicle and the external environment surrounding the vehicle; iii.
sound enters the housing through the one or more openings of the
housing and is reflected off one or more walls defining the chamber
thereby canceling at least a portion of the sound; and iv. the
chamber is adjacent to a fluid flow path between the first and
second openings such that first sound from the external environment
enters the chamber, is reflected off of a rear wall of the chamber
and cancels other second sound entering the chamber such that the
first and second sound do not continue along the fluid flow path,
the second sound having a wavelength within 6 cm of the first
sound, the rear wall being a distance of within 4 cm of a 1/4 of
the wavelength of the first and/or second sound from a central area
of an opening that provides fluid communication to the passenger
compartment.
19. A system as in claim 18 wherein the housing is substantially
entirely formed of plastic.
20. A system as in claim 18 wherein an annular seal extends about a
periphery of the housing.
Description
CLAIM OF PRIORITY
[0001] This application claims the benefit of the filing date of
U.S. Provisional Application No, 60/711,101 filed Aug. 25,
2005.
FIELD OF THE INVENTION
[0002] The present invention relates generally to a sound reduction
system and a method of using the system to reduce noise for
articles of manufacture such as transportation vehicles (e.g.,
automotive vehicles, trains or the like)
BACKGROUND OF THE INVENTION
[0003] For many years, industry (e.g., the transportation industry)
has been concerned with designing systems for limiting the transfer
of sound to certain locations such as the passenger compartment of
an automotive vehicle. In certain instances, however, it can also
be desirable for these systems to allow a fluid such as air to flow
through the system while still maintaining the ability of the
system to limit sound transfer. For example, it may be desirable
for air to flow through a system in order to relieve elevated air
pressure in a passenger compartment of an automotive vehicle (e.g.,
when a door of that vehicle is closed or the HVAC system is turned
on). Thus, the present invention seeks to provide a system that
limits sound transfer, but which also allows a fluid such as air to
flow through at least a portion of the system.
SUMMARY OF THE INVENTION
[0004] A system for reducing the passage of sound from a first
location to a second location is disclosed. The system typically
includes a structure of an article of manufacture and a housing
adjacent the structure and adjacent a fluid flow path. The flow
path typically allows fluid flow from the first location to the
second location and the flow path is typically adjacent a chamber
such that sound can enter the chamber, reflect of one or more walls
of the chamber and be canceled. The system has been found
particularly effective for reducing noise in automotive
vehicles.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The features and inventive aspects of the present invention
will become more apparent upon reading the following detailed
description, claims, and drawings, of which the following is a
brief description:
[0006] FIG. 1 is a perspective view of an exemplary sound reduction
system according to one aspect of the present invention.
[0007] FIG. 2 is a sectional view of the exemplary sound reduction
system of FIG.
[0008] FIG. 3 is a perspective view of a portion of the exemplary
chamber of a sound reduction system according to an aspect of the
present invention.
[0009] FIG. 4 is a side view of the exemplary sound reduction
system of FIG. 1 being assembled to an exemplary structure of an
article of manufacture.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0010] The present invention is predicated upon providing a sound
reduction system for reducing the amount of sound passing from a
first location to a second location. The sound reduction system has
found particular utility for automotive vehicles although it is
contemplated that the system may be applied to a variety of
articles of manufacture such as airplanes, boats, buildings,
furniture, appliances or the like.
[0011] Accordingly, the system of the present invention typically
includes one or more of the following: [0012] 1) a structure of an
article of manufacture (e.g., an automotive vehicle) that
preferably includes a wall having an opening; [0013] 2) a housing
configured for attachment to the structure wherein: the housing
typically substantially surrounds a chamber; the housing typically
includes one or more openings (e.g., a first opening and a second
opening) in fluid communication with the chamber; and the chamber
is typically located beside a path through or connecting the one or
more openings; and [0014] 3) optionally, a seal is associated with
the housing and configured for sealing between the housing and the
structure of the article of manufacture.
[0015] Typically, the system is designed such that sound waves
entering the housing are reflected off of one or more walls
defining the chamber. After refection, the reflected sound waves
interact (e.g., collide) with other sound waves (e.g., incoming
sound waves), reflected or non-reflected, entering or moving within
the chamber. Typically, and without being bound by any particularly
theory, the interaction of these sound waves tends to cancel or
otherwise at least partially destroy the sound waves thereby
reducing the amount of sound exiting the housing relative to the
amount of sound entering the housing.
[0016] Referring to FIGS. 1-3, there is illustrated an exemplary
system 10 according to an aspect of the present invention. The
system 10 is generally designed for reducing sound, particularly
undesirable noise, within an article of manufacture such as an
automotive vehicle. The system includes a housing 12 surrounding a
substantial portion (e.g., at least 50%, 70%, 90% or more) or
substantially the entirety of an internal chamber 14. The housing
12 additionally includes (e.g., defines) one or more openings 16,
18. As used herein, the housing can be any member or structure or
group of members or structures that surround and/or define a
substantial portion of an internal chamber.
[0017] Housing will typically have no specific shape unless
otherwise specifically recited. It should also be noted that the
housing may include pad of the structure to which it is installed
(as is described further below). For example, a portion of the
housing may generally define a cavity, but may only substantially
surround the internal chamber when that portion of the housing is
attached to a wall of a structure such that the wall completes the
housing such that the housing substantially entirely surrounds the
internal chamber.
[0018] The illustrated housing 12 is shaped as a rectangular box
with five sides. The housing may be formed of a variety of
materials such as polymeric materials (e.g., plastics), metals,
glass, fibrous materials, combinations thereof or the like.
[0019] The one or more openings of the system or housing will
typically assist in providing a flow path for allowing fluid to
flow therethrough. Moreover, the one or more openings will
typically be in fluid communication with the chamber of the
housing. In the embodiment illustrated, the housing includes a
first opening 16 in fluid communication with a second opening 18.
As illustrated by a curved or bent arrow 22, a fluid flow path
interconnects or provides fluid communication between the first
opening 16 and the second opening 18.
[0020] The chamber of the system is typically in fluid
communication with the one or more openings of the housing or
system and the chamber is configured for receiving sound (i.e.,
sound waves) that enter the housing through the one or more
openings. The chamber is typically located adjacent (e.g., beside)
the flow path created by the one or more openings. In the
embodiment of FIGS. 1, 2 and 4, the chamber 14 is located beside
the path 22 traveling from the first opening 16 to the second
opening 16. Moreover, the exemplary chamber 14 is located closer to
a first end 26 of the housing 12 relative to both the first and
second openings 16, 18.
[0021] It is contemplated that the chamber may have a single
consistent or multiple different depths relative to the one or more
openings of the housing. As used herein, a depth or depths of the
chamber are distances between the one or more openings to one or
more rear walls. Typically, a depth can be measured as the length
of a line segment that extends from a rear wall to a closest center
point of the closest of the one or more openings. The center point
is a point at which the line segment extends half way across the
openings. Such a depth measurement is labeled (D) in FIGS. 1 and 2.
A single consistent depth can be achieved by having a rear wail
(i.e., a wall furthest from the one or more openings) that is
substantially consistently equidistant (i.e., within 5 cm, more
typically within 2 cm and even more typically within 1 cm of
equidistant) from the center points of the one or more openings.
Such a rear wall 30 is illustrated in the embodiment of FIGS. 1 and
2 and such wall 30 is substantially equidistant at a distance (D)
from the opening 18 of the housing 12.
[0022] In the particular embodiment illustrated, the housing 12,
the chamber 14 or both are divided into multiple sub-chambers 34 by
one or more (e.g., 1, 2, 3, 4, 5, or more) divider walls 36. Each
sub-chamber 34 provides access to the rear wall and/or extends from
the openings 16, 18 to or toward the rear wall 30.
[0023] As suggested, the chamber of the present invention may have
multiple depths. Multiple depths can be achieved by angling or
contouring the rear wall or, alternatively, providing multiple rear
walls at multiple different distances from the one or more
openings. Advantageously, whether using a single or multiple
depths, the chamber can be tuned for diminishing or canceling
certain undesirable sound or noise as discussed further below. A
chamber 40 of FIG. 3 is illustrated to include multiple rear walls
42, 44, 46, 48, 50 at multiple depths.
[0024] Optionally, the sound reduction system of the present
invention may include a sealing material for attaching and/or
sealing the system or housing to a structure of an article of
manufacture. The system 10 of FIGS. 1-3 includes a sealing material
56 extending about an attachment 58 of the housing 12 or system 10.
In the exemplary embodiment illustrated the sealing material 56
extends substantially continuously about the attachment 58.
Generally, the skilled artisan will be able to think of several
attachments and/or sealing materials that may be employed within
the scope of the present invention.
[0025] The sealing material may be formed of a variety of materials
since, as the skilled artisan would recognize, many different
suitable sealing materials have been or will be developed. As one
example, the sealing material may be formed of material including
or substantially entirely comprised of a polymeric material that
includes an elastomer, a plastic or a combination thereof.
[0026] In one preferred embodiment, the sealing material is formed
of an activatable material. Various activatable materials may be
employed in the present invention. For example, a heat activated
material having foamable characteristics may be employed. The
material may be generally dry to the touch or tacky and can be
placed upon or adjacent any of the components of the housing or
system in any form or desired pattern, placement, or thickness.
Exemplary materials include L-5248, L-7002, L-7102, L-7104, L2105
and L-5204 foams available through L&L Products, Inc. of Romeo,
Mich.
[0027] A number of reinforcing, sealing and/or baffling materials
are known in the art and may also be used to produce foam. A
typical foam includes a polymeric base material, such as an epoxy
resin, an ethylene-based polymer, an acrylate and/or acetate based
material or a combination thereof which, when compounded with
appropriate ingredients (typically a blowing and curing agent),
expands and cures in a reliable and predictable manner upon the
application of heat or the occurrence of a particular ambient
condition. From a chemical standpoint for a thermally-activated
material, the structural foam is usually initially processed as a
flowable thermoplastic material before curing. Typically, the
material will cross-link upon curing (e.g., become thermoset),
which makes the material incapable of further flow.
[0028] Examples of preferred foam formulations are EVA based and
epoxy-* based materials that are commercially available from
L&L Products of Romeo, Mich., under the designations L7220,
L5206, L5207, L5208, L5209, L5218, L5224, L-5248, XP321 and XP721.
Other suitable sealing materials include elastomeric materials
(e.g., elastomeric gaskets). Additional materials include
polyurethanes or other materials all of which may be formed into
gaskets or other configurations.
[0029] The system of the present invention may be employed in
several different articles of manufacture as previously discussed.
Thus, the system may be assembled to multiple different structures
For exemplary purposes, however,
[0030] the system 10 of FIGS. 1-2 is shown as being assembled to a
structure 70 (e.g., a pillar or rearward wall of a passenger
compartment) of an automotive vehicle (e.g., a car, a truck, an SUV
or the like) in FIG. 4.
[0031] Preferably, although not required, the structure to which
the system is assembled will be configured for allowing the passage
of a fluid (e.g., air) between a first location within the article
of manufacture and a second location within the article of
manufacture or external to the article of manufacture. For example,
a pillar structure or other structure (e.g., a rearward passenger
compartment wall) of an automotive vehicle may have an opening in
fluid communication with an interior space or cabin (e.g.,
passenger compartment) of an automotive vehicle and in fluid
communication with an external or ambient environment surrounding
the vehicle. In this manner, air can flow into or out of it the
interior cabin for avoiding undesirable low or high levels of
pressure within the interior cabin. Generally, the system of the
present invention is installed to such a structure such that the
fluid or air flow is directed through the one or more openings of
the housing or system.
[0032] In FIG. 4, the structure 70 illustrated is in fluid
communication with an interior cabin of a vehicle and an exterior
environment surrounding the vehicle through one or more openings 74
in the structure 70. The system 10 is installed to the structure 70
by attaching the housing 12 to the structure 70 such that the one
or more opening 16, 18 of the housing are in fluid communication
with the opening 74 of the structure 70. In the embodiment
illustrated, the attachment 58 is interference fit within the
opening 74 of the structure 30 thereby aligning and allowing fluid
communication between the opening 74 of the structure and the
second opening 18 of the housing 12. Such attachment also places
the first opening 16 of the housing 12 in fluid communication with
an external or ambient environment 80 surrounding the vehicle.
Thus, both the first opening 16 and the second opening 18 are in
fluid communication with the passenger compartment and the ambient
environment Once installed, the first and second openings 16; 18 of
the housing 12 may be in fluid communication with the passenger
compartment directly or through second any openings (not shown) in
the structure or other par of the vehicle.
[0033] Preferably, upon installation, the sealing material 56
creates a substantially fluid tight seal between the structure 70
and the housing 12 and/or attachment 58 thereby encouraging any
flow of air to go through the openings 16, 18 of the housing 12.
Such a seal may be created by interference fitting the attachment,
the sealing material 56 or both with the opening 74 of the
structure 70. When an activatable material is employed as the
sealing material, the activatable material is typically heat
activated (e.g., in a paint or e-coat bake oven) to expand (e.g.,
foam) and cure thereby adhering the material to the structure, the
housing or both. It is also contemplated that the system, and
particularly the housing, may be attached additionally or
alternatively to the structure with one or more fasteners (e.g.,
mechanical fasteners such as push pins, brackets and screws or
others).
[0034] Advantageously, the system of the present invention can be
employed in a situation where it is desirable to inhibit the
transmission of sound while still allowing the flow of a fluid such
as air therethrough. For example, in FIG. 4, the structure 70 of
the vehicle remains in fluid communication with the interior cabin
(e.g., passenger compartment) of the vehicle and in fluid
communication with an ambient environment 80 surrounding the
vehicle as discussed. Thus, for is example, upon closing of a
vehicle door, use of an air conditioning system or the like, air
from the interior cabin can flow to the ambient environment thereby
avoiding an undesirable elevated pressure within the cabin of the
vehicle. In addition, sound waves (e.g., noise) from the ambient
environment or other locations of the vehicle that go into the
housing (typically through the first opening 16) will typically go
into the chamber 14. These sound waves will then be reflected
within the chamber 14 (e.g., off of one or more rear walls) and
such sound waves will tend to cancel or reduce each other thereby
limiting the amount of sound that travels to the cabin of the
vehicle.
[0035] As is known, sound waves can have many different
frequencies. Thus, as an added advantage to the system of the
present invention, the chamber 14 can be designed to target
reduction of particular frequencies. It has been found that the
depth (D) or depths (e.g., D.sub.1, D.sub.2, D.sub.3, D.sub.4) of
the chamber 14 can be tuned to target particular frequencies.
Generally, it is believed that the depth (D) or depths (e.g.,
D.sub.1, D.sub.2, D.sub.3, D.sub.4) should be 1/4 of the wavelength
of the sound or noise that it is desirable to cancel. Thus, a
single depth can be employed for significantly reducing sound waves
of one particular range of frequencies while multiple depths can be
employed for reducing sound waves of multiple different frequency
ranges.
[0036] Setting a depth to 1/4 of a particular wavelength will
typically assist in canceling noise at a particular frequency of
the wavelength and a range of frequencies above and below that
particular frequency. Thus, the system is not limited to canceling
only sound at the particular frequency that corresponds to the
wavelength for which the depth is 1/4 that wavelength but can
cancel ranges of sound.
[0037] For guidance the following table is provided for assisting
in determining the depth or depths suitable for the chamber when
targeting certain frequency ranges: TABLE-US-00001 TABLE
Frequencies (Hz) Wavelengths (m) Depths (m) 250 .+-. 10% 1.360 .+-.
20% 0.340 .+-. 30% 500 .+-. 10% 0.680 .+-. 20% 0.170 .+-. 30% 800
.+-. 10% 0.425 .+-. 20% 0.106 .+-. 30% 1000 .+-. 10% 0.340 .+-. 20%
0.085 .+-. 30% 2000 .+-. 10% 0.170 .+-. 20% 0.043 .+-. 30% 4000
.+-. 10% 0.085 .+-. 20% 0.021 .+-. 30%
[0038] For the present invention, the use of .+-.a percentage means
plus or minus the percentage of that number. For example 100.+-.30%
means 70 to 130. One particularly desirable range or frequencies
that are desirable to eliminate are in the 800.+-.20% Hz.
[0039] In addition to the above, it is contemplated that the sound
reduction system may include other features as well. For example
the one or more openings of the housing may be covered with
actuation or moving members such as flaps. Such member would
typically cover the one or more openings until air pressure
gradients cause the members to move and uncover the openings such
that air can flow through the openings. It is also contemplated
that one or more masses of material such as foam or activatable
material may be located within the chamber for assisting in
absorbing sound.
[0040] Unless stated otherwise, dimensions and geometries of the
various structures depicted herein are not intended to be
restrictive of the invention, and other dimensions or geometries
are possible. Plural structural components can be provided by a
single integrated structure. Alternatively, a single integrated
structure might be divided into separate plural components. In
addition, while a feature of the present invention may have been
described in the context of only one of the illustrated
embodiments, such feature may be combined with one or more other
features of other embodiments, for any given application. It will
also be appreciated from the above that the fabrication of the
unique structures herein and the operation thereof also constitute
methods in accordance with the present invention.
[0041] The preferred embodiment of the present invention has been
disclosed. A person of ordinary skill in the art would realize
however, that certain modifications would come within the teachings
of this invention. Therefore, the following claims should be
studied to determine the true scope and content of the
invention.
* * * * *