U.S. patent application number 12/264378 was filed with the patent office on 2009-05-21 for damping structure.
Invention is credited to Jun-Hyun Han, Kwang-Koo Jee, Yoon-Bae Kim.
Application Number | 20090126289 12/264378 |
Document ID | / |
Family ID | 40640504 |
Filed Date | 2009-05-21 |
United States Patent
Application |
20090126289 |
Kind Code |
A1 |
Jee; Kwang-Koo ; et
al. |
May 21, 2009 |
DAMPING STRUCTURE
Abstract
The present invention relates to a damping structure which is
capable effectively damping vibration of a structure. The damping
structure includes a vibration controlling medium fixed at a
structure and vibrating with an amplitude greater than that of the
structure upon vibration and a damper vibrating separately from the
vibration controlling medium as a result of being loosely fitted
into the vibration controlling medium or a damper supporter
extended therefrom, and thus having a vibration frequency different
from that of the vibration controlling medium.
Inventors: |
Jee; Kwang-Koo; (Seoul,
KR) ; Kim; Yoon-Bae; (Seoul, KR) ; Han;
Jun-Hyun; (Seoul, KR) |
Correspondence
Address: |
OSTROLENK FABER GERB & SOFFEN
1180 AVENUE OF THE AMERICAS
NEW YORK
NY
100368403
US
|
Family ID: |
40640504 |
Appl. No.: |
12/264378 |
Filed: |
November 4, 2008 |
Current U.S.
Class: |
52/167.2 |
Current CPC
Class: |
F16F 7/10 20130101; F16F
7/104 20130101 |
Class at
Publication: |
52/167.2 |
International
Class: |
E04B 1/98 20060101
E04B001/98 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 8, 2007 |
KR |
10-2007-0113848 |
Claims
1. A damping structure comprising: a vibration controlling medium
fixed at a structure and vibrating with an amplitude greater than
that of the structure upon vibration; and a damper vibrating
separately from the vibration controlling medium as a result of
being loosely fitted into the vibration controlling medium or a
damper supporter extended therefrom, and thus having a vibration
frequency different from that of the vibration controlling
medium.
2. The damping structure of claim 1, wherein the damper is loosely
fitted by passing through a hole formed at the vibration
controlling medium or a damper supporter extended therefrom.
3. The damping structure of claim 2, further comprises a sub damper
loosely encompassing the damper.
4. The damping structure of claim 2, wherein the damper is formed
in a rivet shape.
5. The damping structure of claim 2, further comprises a sub damper
disposed in the damper and vibrating separately from the
damper.
6. The damping structure of claim 1, wherein the damper is loosely
encompassing the vibration controlling medium or a damper supporter
extended therefrom.
7. The damping structure of claim 1, wherein the damper is disposed
in the damper supporter.
8. The damping structure of claim 1, wherein the damper is defined
by a space formed by the damper supporter and the vibration
controlling medium.
9. The damping structure of claim 1, wherein the damper separately
vibrates in a state that one point thereof is fixed at the
vibration controlling medium or the damper supporter extended
therefrom.
10. The damping structure of claim 1, wherein the vibration
controlling medium is implemented as a plate having a thickness
thinner than a plate forming the structure.
11. The damping structure of claim 10, wherein the vibration
controlling medium is implemented as the plate having a thickness
of 0.5.about.3.5.
12. The damping structure of claim 1, wherein the vibration
controlling medium is adhered to the structure in a welding
manner.
13. The damping structure of claim 2, wherein the vibration
controlling medium is implemented as a plate having a thickness
thinner than a plate forming the structure.
14. The damping structure of claim 3, wherein the vibration
controlling medium is implemented as a plate having a thickness
thinner than a plate forming the structure.
15. The damping structure of claim 4, wherein the vibration
controlling medium is implemented as a plate having a thickness
thinner than a plate forming the structure.
16. The damping structure of claim 5, wherein the vibration
controlling medium is implemented as a plate having a thickness
thinner than a plate forming the structure.
17. The damping structure of claim 6, wherein the vibration
controlling medium is implemented as a plate having a thickness
thinner than a plate forming the structure.
18. The damping structure of claim 7, wherein the vibration
controlling medium is implemented as a plate having a thickness
thinner than a plate forming the structure.
19. The damping structure of claim 8, wherein the vibration
controlling medium is implemented as a plate having a thickness
thinner than a plate forming the structure.
20. The damping structure of claim 9, wherein the vibration
controlling medium is implemented as a plate having a thickness
thinner than a plate forming the structure.
21. The damping structure of claim 13, wherein the vibration
controlling medium is implemented as the plate having a thickness
of 0.5.about.3.5.
22. The damping structure of claim 14, wherein the vibration
controlling medium is implemented as the plate having a thickness
of 0.5.about.3.5.
23. The damping structure of claim 15, wherein the vibration
controlling medium is implemented as the plate having a thickness
of 0.5.about.3.5.
24. The damping structure of claim 16, wherein the vibration
controlling medium is implemented as the plate having a thickness
of 0.5.about.3.5.
25. The damping structure of claim 17, wherein the vibration
controlling medium is implemented as the plate having a thickness
of 0.5.about.3.5.
26. The damping structure of claim 18, wherein the vibration
controlling medium is implemented as the plate having a thickness
of 0.5.about.3.5.
27. The damping structure of claim 19, wherein the vibration
controlling medium is implemented as the plate having a thickness
of 0.5.about.3.5.
28. The damping structure of claim 20, wherein the vibration
controlling medium is implemented as the plate having a thickness
of 0.5.about.3.5.
Description
RELATED APPLICATION
[0001] The present disclosure relates to subject matter contained
in priority Korean Application No. 10-2007-0113848, filed on Nov.
8, 2007, which is herein expressly incorporated by reference in its
entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a damping structure which
is capable of effectively damping vibration of structures.
[0004] 2. Background of the Invention
[0005] Vibration of a structure causes great damage to a workplace.
The vibration of the structure causes a noise. And, the noise may
cause a noise-induced hearing loss to workers, which takes the
first rank in vocational diseases and causes the workers to shirk
working in a manufacturing part. Also, the vibration causes
weariness and cracks to the structure such as a manufacturing
plant. In addition, due to the vibration, it may be difficult to
perform precise processes.
[0006] Various methods for suppressing vibration of a structure
have been proposed so far.
[0007] One of them is using a special alloy having a high vibration
damping (absorbing) force in itself. However, this method requires
composition of the special alloy and a special process, thus it is
seriously difficult to satisfy all of a cost, a mechanical
performance and vibration suppression performance. Various alloys,
such as Fe--Al based, Fe--Cr based, Mn--Cu based alloys, have been
developed, however, they have hardly been commercially used.
[0008] As another method, a composite resin metallic plate in which
a resin is interposed between metallic plates, that is, a sandwich
steel plate structure is proposed. This structure implements
excellent damping characteristic and mechanical performance.
However, a special device is required for fabrication, which causes
a fabrication cost to increase. And, it has an inferior welding or
molding characteristic, thus it has a limitation to be used.
[0009] Besides, there are a method for increasing a mass and
stiffness using a thick material and a method using a cover or a
noise suppresser. However, these methods respectively have
drawbacks that a weight may increase and that it is effective only
in a limited space.
SUMMARY OF THE INVENTION
[0010] Therefore, a first object of the present invention is to
provide a damping structure which is excellent in aspects of a
cost, a mechanical characteristic and vibration damping performance
and has compatibility with various devices.
[0011] A second object of the present invention is to provide a
damping structure which is capable of being easily fabricated
because it can be installed only by a simple process and of
reducing an installation cost and time. Particularly, the damping
structure according to the present invention is configured to be
installed in a state that a structure to be damped is an end
product, accordingly it is capable of obtaining a damping effect by
simply installing the damping structure without changing a
structure of a pre-fabricated device.
[0012] A third object of the present invention is to provide a
damping structure which is capable of substantially damping
vibration without increase of a weight and of being installed
regardless of an installation space.
[0013] A fourth object of the present invention is to provide a
damping structure which is capable of damping vibration of a
structure formed by a thick metallic plate or a container for
storing liquid.
[0014] To achieve these and other advantages and in accordance with
the purpose of the present invention, as embodied and broadly
described herein, there is provided a damping structure comprising
a vibration controlling medium fixed at a structure and vibrating
with an amplitude greater than that of the structure upon
vibration; and a damper vibrating separately from the vibration
controlling medium as a result of being loosely fitted into the
vibration controlling medium or a damper supporter extended
therefrom, and thus having a vibration frequency different from
that of the vibration controlling medium.
[0015] The foregoing and other objects, features, aspects and
advantages of the present invention will become more apparent from
the following detailed description of the present invention when
taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The accompanying drawings, which are included to provide a
further understanding of the invention and are incorporated in and
constitute a part of this specification, illustrate embodiments of
the invention and together with the description serve to explain
the principles of the invention.
[0017] In the drawings:
[0018] FIG. 1 is a side view showing a damping structure in
accordance with a first exemplary embodiment of the present
invention;
[0019] FIG. 2 is a section view showing a structure of a damper
used in the damping structure of FIG. 1;
[0020] FIG. 3 is a view schematically showing a device for
measuring a specific damping capacity according to a thickness of a
metallic plate;
[0021] FIG. 4 is a graph showing a method for measuring a strain
caused by free vibration of a metallic plate;
[0022] FIG. 5 is a graph showing a specific damping capacity
according to a thickness of a metallic plate;
[0023] FIG. 6 is a view schematically describing a principle
applied to the present invention;
[0024] FIGS. 7 to 19 are section views or perspective view showing
damping structures in accordance with each embodiment of the
present invention; and
[0025] FIG. 20 is a graph showing results of measurement of
specific damping capacity in a comparative example and a preferred
example of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0026] Description will now be given in detail of the present
invention, with reference to the accompanying drawings.
[0027] The present invention is configured to attach a vibration
controlling medium to a structure and then control vibration of the
vibration control medium so as to control vibration of the
structure.
[0028] Referring to FIG. 1, a damping structure 1 in accordance
with a first embodiment of the present invention includes a
vibration controlling medium 10 and a damper 20 controlling
vibration of the vibration controlling medium 10.
[0029] The vibration controlling medium 10 is configured to be
fixed to a structure (S) in a welding manner, and to have amplitude
greater than that of the structure (S) at a time of vibration. To
this end, in this embodiment, the vibration controlling medium 10
is implemented as a plate having a thickness lower than that of a
plate forming the structure (S). The vibration controlling medium
10 may be formed of various materials such as metal, ceramic,
rubber according to a vibration condition.
[0030] Also, the damper 20 is loosely fitted into the vibration
controlling medium 10, and thus separately vibrates from the
vibration controlling medium 10. Accordingly, the damper 20 has a
vibration frequency different from that of the vibration
controlling medium 10. Referring to FIG. 2, the damper 20 is
loosely fitted into the vibration controlling medium 10 by passing
through a hole formed at the vibration controlling medium 10,
accordingly the damper 20 vibrated separately from the vibration
controlling medium 10. In this embodiment, the damper 20 is formed
in a rivet shape, but it is not limited thereto. And, though it is
not shown, the damper 20 also may be loosely fitted into a damper
supporter extended from the vibration controlling medium 10 by
passing through a hole formed at the damper supporter.
[0031] In the present invention, a principle that the damper 20
controls the vibration of the vibration controlling medium 10 is
using a collision between two members 10, 20 respectively
vibrating. That is, when respectively vibrating the damper 20 and
the vibration controlling medium 10, two members 10, 20 collide
with each other because each vibration frequency of the two members
10, 20 is different from each other. Accordingly, the vibration can
be damped.
[0032] To properly execute a performance of the damping structure,
effect of the collision between two members 10, 20 should be great.
Thus, the amplitude of the vibration controlling medium 10 should
be large. A simple method for increasing the amplitude of the
vibration control medium 10 is reducing a thickness of the
vibration controlling medium 10. However, a metallic plate forming
a structure used for a plant has a thickness of 10 mmin many cases,
and it is difficult to make a hole in a container containing fluid
therein. Therefore, in the present invention, the vibration
controlling medium is attached to a structure and then the
vibration of the vibration controlling medium is controlled using
the damper so as to control the vibration of the structure, rather
than directly installing the damper at the structure.
[0033] To research how thick the metallic plate should be so as to
be suitable for the damper shown in FIG. 2, multiple metallic
plates 30 having different thickness from each other are made to
have holes and then a damper 40 formed in a rivet shape same as
FIG. 2 is installed in each hole, as shown in FIG. 3. A strain gage
sensor is attached onto each metallic plate 30. And then, each
metallic plate 30 executes in a free vibration mode so as to
measure a strain. The measured strain is represented in FIG. 4 and
evaluated as a Specific Damping Capacity (SDC) of the following
formula (I):
SDC=(.epsilon..sup.2.sub.n-.epsilon..sup.2.sub.n+1)/.epsilon..sup.2.sub.-
n Formula (1)
[0034] Here, .epsilon..sub.n denotes a strain occurring at a time
of n.sup.th vibration and .epsilon..sub.n+1 denotes a strain
occurring at a time of n+1.sup.th vibration. Since an elastic
energy is proportional to the square of a value of the strain, the
formula (1) indicates a ratio of an energy absorbed when vibration
of one cycle is generated.
[0035] FIG. 5 shows an SDC according to a thickness of the metallic
plate 30. Referring to FIG. 5, approximately 25% of SDC was
obtained when the thickness of the metallic plate is 0.5 mm. The
SDC rose to the maximum as 43% and 40% respectively, when each
thickness of the metallic plates is respectively 1.0 mm and 1.5 mm
and then drastically decreased. And, when the thickness of the
metallic plate is over 3.5 mm, the vibration damping effect was
hardly obtained. This is because, in the same strain, a thin
metallic plate increases the amplitude to enhance the collision
effect of the damper, but a thick metallic plate decreases the
amplitude upon vibration so as to lower the collision effect.
Therefore, when using the damper shown in FIG. 2, the thickness of
the metallic plate has great influence thereon. The vibration
damping effect can be greatly obtained in a thickness of
0.5.about.3.5 mm, preferably, 1.about.1.5 mm.
[0036] In many cases, structures or manufacturing facilities at a
noisy place such as a plant are formed by a steel plate having a
thickness of several tens of mm. In these cases, if the damper
having the structure shown in FIG. 2 is directly installed, the
vibration damping effect is hardly obtained as shown in FIG. 5.
[0037] To solve such problem, the present invention is configured
to adhere a thin plate 60 to serve as a vibration controlling
medium onto a thick plate 50 forming a structure in a welding
manner. When an impact is applied to the thick plate 50 from
outside, both of the plates 50, 60 may vibrate together. In this
case, the thick plate 50 may vibrate with small amplitude and the
thin plate 60 may vibrate with large amplitude. Here, if the thin
plate 60 is forced not to vibrate, the thick plate 50 may easily
stop vibrating. Accordingly, when adhering the thin plate 60 having
a proper thickness onto the thick plate 50, as shown in FIG. 6, and
then installing the damper configured as shown in FIG. 2 at the
thin plate 60, it is capable of easily damping the vibration. The
thick plate 50 corresponds to the structure (S) shown in FIG. 1 and
the thin plate 60 corresponds to the vibration controlling medium
10 shown in FIG. 1. As aforementioned, the thin plate, that is, the
vibration controlling medium, had better have a thickness of
0.5.about.3.5 mm, preferably, 1.about.1.5 mm so as to enhance the
vibration damping effect.
[0038] The damper 20 shown in FIGS. 1 and 2 can be configured to
have various modifications. The modifications are illustrated in
FIGS. 7 to 19. However, the present invention is not limited to the
modifications.
[0039] Referring to FIG. 7, the damping structure according to the
present invention further includes a sub damper 130 formed in a
washer shape and loosely encompassing the damper 120, as well as
the damper 120 formed in the rivet shape loosely fitted into the
vibration controlling medium 110 with passing through a hole formed
in the vibration controlling medium 110. Here, the sub damper 130
has a vibration frequency different from that of the vibration
controlling medium 110 and assists the damper 120 executing the
damping operation. As another embodiment, the reference numeral 110
in FIG. 7 may be a damper supporter extended from the vibration
controlling medium, not the vibration controlling medium. Here, the
term "extended" may be applied to both a case that the damper
supporter is coupled and fixed to the vibration controlling medium,
as a member separated from the vibration controlling medium, and a
case that the damper supporter is integrally formed with the
vibration controlling medium.
[0040] Referring to FIGS. 8 and 9, damping structures according to
the present invention further include sub dampers 230, 230a
disposed in dampers 220, 220a and vibrating with being separated
from dampers 220, 220a, respectively, as well as the dampers 220,
220a loosely fitted into a vibration controlling medium 210 with
passing through a hole formed in the vibration controlling medium
210. As another embodiment, the reference numeral 210 in FIGS. 8
and 9 may be a damper supporter extended from the vibration
controlling medium, not the vibration controlling medium.
[0041] Referring to FIGS. 10 to 13, dampers 320, 420, 420a, 420b
forming a damping structure according to the present invention
loosely encompass damper supporter 340, 440, 440a, 440b extended
from a vibration controlling medium. As another embodiment, a
reference numeral 340 shown in FIG. 10 may not denote the damper
supporter but denote the vibration controlling medium.
[0042] Referring to FIG. 14, a damper 520 forming a damping
structure of the present invention is disposed in a damper
supporter 540 extended from a vibration controlling medium 510.
[0043] Referring to FIGS. 15 and 16, dampers 620, 620a forming
damping structures of the present invention are defined by a space
formed by the damper supporters 640, 640a and the vibration
controlling medium 610.
[0044] Referring to FIGS. 17 to 19, dampers 720, 720a, 720b forming
damping structures of the present invention separately vibrate in a
state that each one point thereof is fixed at a vibration
controlling medium 710. As another embodiment, the reference
numeral 710 shown in FIGS. 17 to 19 may denote a damper supporter
extended from the vibration controlling medium, not the vibration
controlling medium.
EMBODIMENT
[0045] A vibration experiment was executed with respect to a carbon
steel plate of 250 mm (length).times.250 mm (width).times.15 mm
(thickness). In a comparative example, there was no additional
installation. In a comparative example, metallic plates
respectively having a length of 100 mm, a width of 15 mm and a
thickness of 1.0 mm were adhered to four edges of the carbon steel
plate. And then, the dampers formed in a rivet shape were installed
as shown in FIG. 1 by boring holes in the metallic plate.
[0046] After impacting the carbon steel plate by shooting a steel
ball of 1 kgin a speed of 1 m/sec, the vibration of the carbon
steel plate was measured using a strain gage sensor attached onto
the carbon steel plate. As a result, in case of the comparative
example, the vibration lasted for approximately 0.2 seconds after
the impact. On the other hand, in case of the preferred example,
the vibration lasted for approximately 0.05 seconds, that is,
one-fourth of the vibration time of the comparative example, which
means that the preferred example obtained a great vibration damping
effect (refers to FIG. 20).
[0047] The foregoing embodiments and advantages are merely
exemplary and are not to be construed as limiting the present
disclosure. The present teachings can be readily applied to other
types of apparatuses. This description is intended to be
illustrative, and not to limit the scope of the claims. Many
alternatives, modifications, and variations will be apparent to
those skilled in the art. The features, structures, methods, and
other characteristics of the exemplary embodiments described herein
may be combined in various ways to obtain additional and/or
alternative exemplary embodiments.
[0048] According to the present invention, the vibration
controlling medium is adhered onto the structure and then the
vibration of the vibration controlling medium is controlled using
the damper having a simple structure, accordingly it is capable of
efficiently damping the vibration of the structure. Also, it is
capable of easily controlling vibration with a low cost even in
case of a thick plate or a container for storing liquid, the
container having difficulty in installation of the damper.
[0049] As the present features may be embodied in several forms
without departing from the characteristics thereof, it should also
be understood that the above-described embodiments are not limited
by any of the details of the foregoing description, unless
otherwise specified, but rather should be construed broadly within
its scope as defined in the appended claims, and therefore all
changes and modifications that fall within the metes and bounds of
the claims, or equivalents of such metes and bounds are therefore
intended to be embraced by the appended claims.
* * * * *