U.S. patent application number 11/260483 was filed with the patent office on 2006-05-04 for damper for speaker.
This patent application is currently assigned to PIONEER CORPORATION. Invention is credited to Satoshi Hachiya, Toshihiro Ishigaki, Kazuma Ito, Saori Kuroda, Reo Tanaka.
Application Number | 20060093817 11/260483 |
Document ID | / |
Family ID | 36262320 |
Filed Date | 2006-05-04 |
United States Patent
Application |
20060093817 |
Kind Code |
A1 |
Ishigaki; Toshihiro ; et
al. |
May 4, 2006 |
Damper for speaker
Abstract
A damper for a speaker includes a first fiber having a tensile
strength of equal to or larger than 17 cN/dtex and a second fiber
having a tensile elastic modulus of equal to or smaller than 200
cN/dtex. Thereby, necessary tensile strength and elasticity can be
ensured. In addition, the ratio of the first fiber to the total
amount of the first and second fibers is from 10% to 90%. If the
ratio of the first fiber is smaller than 10%, the necessary tensile
strength and elasticity cannot be obtained. Meanwhile, if the ratio
of the first fiber becomes larger than 90%, punching property at
the time of damper manufacture deteriorates. Thus, it is preferred
that the first fiber is included at the above ratio.
Inventors: |
Ishigaki; Toshihiro;
(Tendo-shi, JP) ; Hachiya; Satoshi; (Tendo-shi,
JP) ; Tanaka; Reo; (Osaka, JP) ; Kuroda;
Saori; (Osaka, JP) ; Ito; Kazuma; (Osaka,
JP) |
Correspondence
Address: |
NIXON & VANDERHYE, PC
901 NORTH GLEBE ROAD, 11TH FLOOR
ARLINGTON
VA
22203
US
|
Assignee: |
PIONEER CORPORATION
Tokyo
JP
TOHOKU PIONEER CORPORATION
Tendo-shi
JP
|
Family ID: |
36262320 |
Appl. No.: |
11/260483 |
Filed: |
October 28, 2005 |
Current U.S.
Class: |
428/364 |
Current CPC
Class: |
H04R 9/043 20130101;
Y10T 428/2913 20150115; D02G 3/047 20130101 |
Class at
Publication: |
428/364 |
International
Class: |
D02G 3/00 20060101
D02G003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 28, 2004 |
JP |
2004-314167 |
Claims
1. A damper for a speaker comprising: first fiber having a tensile
strength of equal to or larger than 17 cN/dtex; and second fiber
having a tensile elastic modulus of equal to or smaller than 200
cN/dtex.
2. The damper for the speaker according to claim 1, wherein a ratio
of the first fiber to a total amount of the first and second fibers
is from 10% to 90%.
3. The damper for the speaker according to claim 1, wherein the
first fiber is one of a para-type aromatic polyamide fiber, an
aromatic polyester fiber, a polyimide fiber, a high tensile
strength polyethylene fiber and a polypara phenylene benzobis
imidazole fiber.
4. The damper for the speaker according to claim 1, wherein the
second fiber is one of a meta-type aromatic polyamide fiber, a
polyester fiber, an acrylic fiber, a polyhenylenesulfide fiber, a
polyamide fiber and a cotton fiber.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a damper for a speaker
device.
[0003] 2. Description of Related Art
[0004] Conventionally, a woven fabric using a meta-type aromatic
polyamide fiber thread, a thread made by mixed-spinning or twining
a meta-type aromatic polyamide thread and a cotton thread, a
polyester fiber thread, a thread made by mixed-spinning or twining
the polyester fiber thread and the cotton thread, and the cotton
thread is generally used as a fabric material of a damper
supporting a vibration system of a speaker device. In addition, the
fabric material including the above-mentioned fibers is normally
impregnated with a thermosetting resin such as a phenol resin, and
is formed by hot press into the damper.
[0005] Examples of the damper for the speaker using the
above-mentioned threads are disclosed in Japanese Patent No.
3287750, Japanese Patent Publication No. 58-30796, and Japanese
Patent Applications Laid-open under No. 8-149597, No. 10-322796 and
No. 62-258596.
[0006] Since strength of the fabric material of the fiber used for
the above-mentioned damper is low, there is a problem in a recent
high-powered speaker that the damper is cut during the operation of
the speaker. Therefore, it is necessary to improve elasticity and
tensile strength of the damper fabric material.
[0007] For the purpose of solving such a problem, there is proposed
a technique of using double fabric materials. However, there are
such problems that the material cost increases, the weight of the
damper increases, a follow-up ability to vibration operation
becomes insensitive and the attached fabric materials peel off.
SUMMARY OF THE INVENTION
[0008] The present invention has been achieved in order to solve
the above problems. It is an object of this invention to provide a
damper for a speaker which has sufficient strength and which never
breaks even when it is applied to a large input speaker.
[0009] According to one aspect of the present invention, there is
provided a damper for a speaker including: first fiber having a
tensile strength of equal to or larger than 17 cN/dtex; and second
fiber having a tensile elastic modulus of equal to or smaller than
200 cN/dtex. Thereby, it becomes possible to ensure the necessary
tensile strength and elasticity.
[0010] In a form of the above damper for the speaker, a ratio of
the first fiber to a total amount of the first and second fibers
may be from 10% to 90%. If the ratio of the first fiber is smaller
than 10%, the necessary tensile strength and elasticity cannot be
obtained. Meanwhile, if the ratio of the first fiber is larger than
90%, a punching property at the time of manufacturing damper
deteriorates. Therefore, it is preferred that the first fiber is
included in the above-mentioned ratio.
[0011] In a preferred example, the first fiber may be a para-type
aromatic polyamide fiber, an aromatic polyester fiber (a high
tensile strength polyarylate fiber), a polyimide fiber, a high
tensile strength polyethylene fiber or a polypara phenylene
benzobis imidazole fiber. Further, in another preferred example,
the second fiber may be a meta-type aromatic polyamide fiber, a
polyester fiber, an acrylic fiber, a polyhenylenesulfide fiber, a
polyamide fiber or a cotton fiber.
[0012] The nature, utility, and further features of this invention
will be more clearly apparent from the following detailed
description with respect to preferred embodiment of the invention
when read in conjunction with the accompanying drawings briefly
described below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 shows a plan view of a damper according to an
embodiment of the present invention;
[0014] FIGS. 2A and 2B show partly-enlarged views of the damper
according to the embodiment of the present invention;
[0015] FIG. 3 schematically shows a manufacturing process of the
damper according to the embodiment;
[0016] FIGS. 4A and 4B show a result of a tensile strength test;
and
[0017] FIG. 5 shows results of tensile strength tests of various
kinds of mixed-woven fabrics.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] The preferred embodiments of the present invention will now
be described below with reference to the attached drawings.
[Structure of Damper]
[0019] FIG. 1 shows a plan view of the damper according to the
present invention. In a speaker device, a damper 10 is fixed to a
voice coil bobbin which vibrates in accordance with an input signal
and a frame of the speaker device body, thereby to elastically
support the voice coil bobbin. Specifically, an inner peripheral
edge 10a is fixed to the voice coil bobbin, and an outer peripheral
edge 10b is fixed to the frame of the speaker device body. In
addition, in the damper 10, plural concentric corrugations 10d are
formed from the inner peripheral edge to the outer peripheral edge.
The damper 10 of the present invention is applicable to various
kinds of speaker devices, irrespective of structures and driving
systems.
[0020] FIGS. 2A and 2B show partly-enlarged views of the damper
according to an embodiment of the present invention. FIG. 2A is the
partly-enlarged view of the damper 10 according to a first
embodiment, which enlarges an area 20 shown in FIG. 1. As shown in
FIG. 2A, the damper 10 is made of a fabric material in which a
fiber having tensile strength of equal to or larger than 17 cN/dtex
and a fiber having a tensile elastic modulus of equal to or smaller
than 200 cN/dtex are used together at the same time. Hereinafter,
the two fibers are referred to as "first fiber" and "second fiber",
respectively.
[0021] "Tensile strength" is a value obtained by dividing a maximum
load (FB), applied until breaking of a material at the time of
applying a tensile load to the material, by an original
cross-sectional area (A) of the material, and it can be expressed
by an equation as follows. Tensile strength TB=FB/A [MPa]
Therefore, as the tensile strength becomes larger, the material
hardly tears, which means that mechanical strength to the tensile
load is high. In addition, "tensile elastic modulus" is a ratio of
a tensile stress within a tensile proportion limit and distortion
caused, at the time of applying the tensile load to an object.
[0022] The examples of the first fiber having the tensile strength
of equal to or larger than 17 dN/dtex are the high tensile strength
fabrics, such as the para-type aromatic polyamide fiber, the
aromatic polyester fiber (high tensile strength polyarylate fiber),
the polyimide fiber and a ultrahigh molecular weight polyethylene
fabric.
[0023] In addition, the examples of the second fiber having the
tensile elastic modulus of equal to or smaller than 200 cN/dtex are
the meta-type aromatic polyamide fiber, the polyester fiber, the
acrylic fiber, the polyphenylenesulfide fiber and a polyethylene
naphthalate fiber.
[0024] In the first embodiment shown in FIG. 2A, each of a first
fiber 31 and a second fiber 32 is alternately arranged to form the
damper 10. Meanwhile, in the second embodiment shown in FIG. 2B,
the first fiber 31 and the second fiber 32 are used in a ratio of
1:5 to form the damper 10. In this manner, the ratio of using the
first fiber and the second fiber is not limited to 1:1, and the
different ratio of using them may be used.
[0025] However, as for the ratio of the first fiber and the second
fiber, the ratio of the first fiber to the whole damper has to be
within 10% to 90%. This is because, if the first fiber is smaller
than 10% of the whole damper, the elasticity and the tensile
strength as the damper fabric material are undesirably
insufficient, similarly to the case that only the second fiber is
used (i.e., the ratio of the first fiber is 0%). Meanwhile, if the
ratio of the first fiber is larger than 90% of the whole damper,
the punching property for punching the damper 10 from the fabric
material into an annular shape shown in FIG. 1 at the time of the
manufacturing damper is decreased, and an efficiency of operation
is undesirably lowered.
[0026] A thread forming the first and second fibers is not limited
to a spun yarn, and a long fiber, a short fiber, a mixed fiber of
them or a finished yarn are applicable. In addition, the
thicknesses of the first fiber and the second fiber may be same or
different.
[0027] Diameters (thicknesses) of the above-mentioned first and
second fibers preferably range from 0.3 dtex to 10 dtex. The fibers
thinner than this range are not preferable because the spinning
property and handling property deteriorate. The fibers thicker than
this range are not preferable because the stress at the time of
curving becomes high, which problematically promotes peeling off
the phenol resin.
[0028] As described above, in the present invention, the damper for
the speaker is formed by using the first fiber having the tensile
strength of equal to or larger than 17 cN/dtex and the second fiber
having the tensile elastic modulus of equal to or smaller than 200
cN/dtex. Thereby, it becomes possible to obtain effects of
improving the elasticity, the tensile strength, durability of the
speaker and punching property of the damper.
[0029] FIG. 3 schematically shows a manufacturing process of the
damper. First, a whole cloth of the fabric material made of the
above-mentioned first and second fibers is impregnated with the
phenol resin. The whole cloth of the fabric material impregnated
with the phenol resin is dried with hot air, and the corrugations
10d shown in FIG. 1 are formed thereto in a hot press process.
Then, in a die cutting process, the fabric material is punched into
the annular shape as shown in FIG. 1. In this way, the damper 10 is
manufactured.
EXPERIMENTAL EXAMPLE
[0030] Next, the description will be given of confirmatory
experimental examples of the above-mentioned respective effects by
the damper of the present invention. In experiments below, a fabric
material of threads of yarn count 10 is used, and the number of
woven warp and weft threads in the fabric material is 25/inch. In
addition, as the first fiber having the tensile strength of equal
to or larger than 17 cN/dtex, a para-type aromatic polyamide fiber
"TECHNORA" (Registered Trademark) produced by TEIJIN TECHNO
PRODUCTS LIMITED is used. As the second fiber having the tensile
elastic modulus of equal to or smaller than 200 cN/dtex, "CONEX"
(Registered Trademark) produced by the same company is used. As
shown in FIG. 2A, each of the first and second fibers is
alternately woven to form the fabric material of the damper.
(Experiment of Elasticity)
[0031] The damper fabric material is cut into a width of 20 mm, and
a 400 g weight is attached thereto. Then, an experiment of curving
the material at the rate of 36 times per minute in a to-and-fro of
180.degree. (90.degree. on one side) is executed. In this
experiment, a number of times at which the damper fabric material
is torn is measured (1 to-and-fro is counted 1 time). The damper
fabric material made of only the second fiber tore at the curving
number of 15000 to 20000 times. Meanwhile, as for the fabric
material according to the above-mentioned embodiment, made of the
first and second fibers, the second fiber was cut at the curving
number of 50000 times, but the first fiber was not cut at the
curving number of 100000 times. Therefore, the fabric material
itself did not tear. As a result, it is confirmed that the
elasticity of the damper fabric material of the present invention
using the first and second fibers is improved.
(Experiment of Tensile Strength)
[0032] The tensile strength of the damper fabric material cut into
a width of 25 mm is measured. FIG. 4A shows a measured result
thereof. The fabric material using only the second fiber tore at
about 650 N. Meanwhile, the fabric material according to the above
embodiment, using the first and second fibers, tore at about 1250
N. As a result, it is confirmed that the tensile strength of the
damper fabric material of the present invention using the first and
second fibers is improved to be approximately double.
[0033] In the case of the fabric material using only the first
fiber, the impregnating property of the phenol resin to the fabric
material is low. Thus, when the stress is set to about 800 N at the
time of the tensile experiment, the weft (cross threads) of the
fabric material held by a tensile testing machine slid and fell
out. FIG. 4B shows this state. When the broken line area 40 is held
by a holding tool of the tensile testing machine and the stress is
applied thereto, the warp remain without being cut, but the weft
slid and shifted. Thereby, it is found out that strength in
practical use of the damper fabric material using the first and
second fibers according to the embodiment of the present invention
is higher.
(Durability Test)
[0034] For the speaker device including the damper fabric material
made of only the second fiber and the speaker device including the
damper made of the first and second fibers according to the
embodiment of the present invention, the continuous-time operation
with 800 W input is executed. The damper made of only the second
fiber is cut within the continuous-time operation of 72 hours.
Meanwhile, the damper made of the first and second fibers according
to the embodiment is not cut within the continuous-time operation
of 72 hours. As a result, it is confirmed that the durability of
the speaker device using the damper fabric material of the present
invention is improved.
(Damper Punching Test)
[0035] In the die-cutting process of the damper shown in FIG. 3,
the damper fabric material using only the second fiber cannot be
die-cut (cut with a die). On the other hand, the damper fabric
material using the first and second fibers according to the
embodiment can be die-cut without any trouble.
[0036] After the forming process by the hot press, the die-cut
process for punching the fabric material into the damper shape can
be easily executed for the second fiber having the tensile elastic
modulus of equal to or smaller than 200 cN/dtex. Meanwhile, even
though the punching is executed for the first fiber having the
tensile strength of equal to or larger than 17 cN/dtex similarly to
the second fiber, the first fiber cannot be often cut due to the
high tensile strength, and the productivity lowers. It is confirmed
that since the damper fabric material according to the embodiment
of the present invention includes the second fiber having the
tensile elastic modulus of equal to or smaller than 200 cN/dtex,
the punching is easier and the productivity is higher compared with
the damper fabric material using only the first fiber.
[0037] In the above embodiment, as the first fiber and the second
fiber, TECHNORA and CONEX are used for the experiment,
respectively. However, even if each of the first and second fibers
using other threads of yarn count 10 is alternately woven such that
the number of woven warp and weft threads is 25/inch, thereby to
manufacture the damper, it is possible to obtain the damper with
the high tensile strength, durability and productivity. FIG. 5
shows tensile strength measuring data by each combination. In the
punching test shown in FIG. 5, it is examined whether or not the
fabric material impregnated with the phenol resin and then formed
by the hot-press can be cut into the damper by the punching in the
damper manufacturing line. As for an item "punching property" shown
in FIG. 5, ".largecircle." shows that the punching is sufficiently
possible, and "X" shows that the punching is impossible.
[0038] In FIG. 5, used "TECHNORA" produced by TEIJIN TECHNO
PRODUCTS LIMITED is used as the para-type aromatic aramid fiber,
"VECTRAN" produced by KURARAY CO., LTD. is used as the aromatic
polyester fiber, "DYNEEMA" produced by TOYOBO.CO., LTD. is used as
a high tensile strength polyethylene fiber, "P84" produced by
TOYOBO.CO., LTD. is used as a polyimide fiber, "ZYLON" produced by
TOYOBO.CO., LTD. is used as a polyphenylene benzobis oxazole fiber
(PBO fiber), "CONEX" produced by TEIJIN TECHNO PRODUCTS LIMITED is
used as the meta-type aromatic polyamide fiber, "TETORON" produced
by TEIJIN TECHNO PRODUCTS LIMITED is used as a polyester fiber,
"VONNEL" produced by MITSUBISHI RAYON CO., LTD. is used as the
acrylic fiber, "TORCON" produced by TORAY INDUSTRIES, INC. is used
as the polyphenylenesulfide fiber, and "TORAY NYLON" produced by
TORAY INDUSTRIES, INC. is used as the polyamide fiber.
[0039] The invention may be embodied on other specific forms
without departing from the spirit or essential characteristics
thereof. The present embodiments therefore to be considered in all
respects as illustrative and not restrictive, the scope of the
invention being indicated by the appended claims rather than by the
foregoing description and all changes which come within the meaning
an range of equivalency of the claims are therefore intended to
embraced therein.
[0040] The entire disclosure of Japanese Patent Application No.
2004-314167 filed on Oct. 28, 2004 including the specification,
claims, drawings and summary is incorporated herein by reference in
its entirety.
* * * * *