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JP2003199192

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DESCRIPTION JP2003199192
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a
speaker damper which is a support system of a diaphragm and a speaker using the damper.
[0002]
2. Description of the Related Art The structure of a conventional speaker and a damper for a
speaker will be described. FIG. 34 is a cross-sectional view showing a structure of a speaker using
a conventional damper. This speaker has a voice coil bobbin 1, a diaphragm 2, a damper 3P, an
edge 4 and a frame 5, as shown in the figure. In the figure, Z indicates the vibration direction of
the voice coil bobbin 1 at the time of operation of the speaker, and R indicates the direction
perpendicular to the Z direction, that is, the radial direction of the speaker.
[0003]
The voice coil 1a is wound around the lower part of the voice coil bobbin 1 and is elastically held
on the frame 5 together with the diaphragm 2 by the damper 3P. The outer peripheral portion of
the diaphragm 2 is vibratably supported by the frame 5 by the edge 4. A magnetic circuit is
formed by the magnet 6, the yoke 7 and the plate 8, and a magnetic flux is generated in the
magnetic gap 9. When a signal current is applied to the voice coil 1a located in the magnetic gap
9, the magnetic flux of the magnetic gap 9 causes the voice coil bobbin 1 to vibrate in the Z
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direction with a driving force proportional to the signal current. The vibration is transmitted to
the diaphragm 2 and a sound is emitted.
[0004]
In such a conventional speaker, in order to vibrate the voice coil bobbin 1 and the diaphragm 2
following the signal current, the cross-sectional shape of the damper 3P is made to be a
waveform. The damper 3P is made easy to vibrate in the Z direction by making the radial
direction of the damper extendible. However, if the cross-sectional shape of the damper 3P is a
waveform, the damper 3P easily vibrates in the R direction. Ideally, the voice coil bobbin 1 and
the diaphragm 3 need only vibrate in the Z direction in proportion to the signal current.
However, in an actual speaker, vibration in the R direction is induced simultaneously with
vibration in the Z direction due to variations in assembly, variations in weight balance, and the
manner of loading due to the installation method.
[0005]
Vibration in the R direction is called a rolling phenomenon. When the rolling phenomenon
occurs, the voice coil 1a strikes the yoke 7 or the plate 8 at the time of operation of the speaker,
an abnormal sound is generated, or the voice coil 1a is destroyed. In addition, if the distance
between the magnetic gaps 9 is increased to prevent the contact phenomenon, the efficiency of
the electroacoustic conversion of the speaker is reduced. Therefore, if the occurrence of the
rolling phenomenon can be suppressed while keeping the gap of the magnetic gap 9 at a
predetermined value, generation of abnormal sound and destruction of the voice coil 1a can be
prevented, and a high-performance speaker with high efficiency can be realized. .
[0006]
There is a damper for a speaker which enhances the rigidity of the damper and prevents the
lowest resonance frequency from changing depending on the level of the signal current (see
Patent Document 1). As shown in FIGS. 1 and 2 of Document 1, a rigid portion 17 is provided on
the inner peripheral portion of the damper member 4. The rigid portion is characterized by
using, for example, a honeycomb structure, a resin sheet, paper, metal, or a material having
rigidity more than the material of the outer peripheral portion. As a result, as shown in FIG. 3,
even if the input power changes, the lowest resonance frequency f0 is less likely to fluctuate.
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2
This invention does not aim to suppress the rolling phenomenon and to ensure the linearity of
the amplitude of the diaphragm.
[0007]
There is also a speaker damper that increases the rigidity of the damper and prevents the lowest
resonance frequency from being displaced by the level of the signal current (see Patent
Document 2). As shown in FIG. 1 and FIG. 2 of the document 2, a raised portion 15 such as a rib
is provided on the inner peripheral portion of the damper member 4. This invention is a device
for preventing the change of the lowest resonance frequency f0 depending on the input level
because the function of the damper for a large amplitude woofer is different between the small
amplitude and the large amplitude. This invention also does not aim to suppress the rolling
phenomenon and to ensure the linearity of the amplitude of the diaphragm.
[0008]
[Patent Document 1] Japanese Utility Model Application Publication No. Sho 62-109596 (Page 1
to 5 pages, FIG. 1, FIG. 2) [Patent Document 2] Japanese Utility Model Application Publication No.
62-109597 (Page 1 to 5 pages, FIG. 1, FIG. 2) Figure)
[0009]
FIG. 35 is a cross-sectional view of a virtual loudspeaker using a flat damper.
If the damper 3Q is completely made flat as in the speaker of this figure, it becomes difficult to
move in the R direction, and the rolling phenomenon can be suppressed. However, at the same
time, since the damper 3Q hardly vibrates in the Z direction, the linearity of the amplitude of the
diaphragm 2 with respect to the driving force can not be obtained, the sound quality of the
speaker is significantly impaired, and the maximum sound pressure is also reduced.
[0010]
In FIG. 36, the planar damper 3Q used in the speaker shown in FIG. 35 is to be analyzed, the
outer periphery of the damper is fixed, a force in the Z direction is applied to the inner periphery,
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and each part of the damper is in the Z direction. When it is made to displace, it is a
characteristic view showing the relation between the radius position and the stress added to the
part. The horizontal axis of FIG. 36 indicates the radial position of each portion in the damper,
and the vertical axis indicates the stress applied to each portion of the damper. As can be
understood from this characteristic, the parts where the stress is large are the outer peripheral
part and the inner peripheral part of the damper. Therefore, if these parts are made to have a
wave-like shape so as to be easily movable in the Z direction, and other parts are made flat so as
to be difficult to move in the R direction, the rolling phenomenon is suppressed and the linearity
of the amplitude of the diaphragm is It should be possible to realize an excellent damper without
damage.
[0011]
The present invention has been made in view of such conventional problems, and it is possible to
hold the diaphragm in a vibratable manner and at the same time secure the linearity of the
amplitude in the vibration direction Z, the voice coil bobbin and the diaphragm It is an object of
the present invention to realize a speaker damper capable of suppressing a rolling phenomenon,
and to provide a speaker using this damper.
[0012]
The invention according to claim 1 of the present application is a speaker damper constituted by
an annular member so as to have a central opening, wherein at least one concave or convex
annular waveform is formed on the outer peripheral portion. An outer peripheral waveform
portion, an inner peripheral waveform portion having at least one concave or convex annular
waveform on an inner peripheral portion adjacent to the central opening, and the outer
peripheral waveform portion provided between the outer peripheral waveform portion and the
inner peripheral waveform portion And a flat portion having a flat surface.
[0013]
The invention according to claim 2 of the present application is characterized in that, in the
speaker damper according to claim 1, the annular width of the flat portion is equal to or greater
than the groove width of the annular waveform of the outer peripheral waveform portion or the
inner peripheral waveform portion. It is a thing.
[0014]
The invention according to claim 3 of the present application is characterized in that, in the
speaker damper according to claim 1, the outer peripheral contour and the inner peripheral
contour of the outer peripheral waveform portion are elliptical, and at least the outer peripheral
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contour of the flat portion is elliptical. It is said that.
[0015]
The invention of claim 4 of the present application is the damper for a speaker according to
claim 1, wherein the Young's modulus in the radial direction of the flat portion is the Young's
modulus in the radial direction of the outer circumferential wave portion and the Young in the
radial direction of the inner circumferential wave portion. It is characterized in that it is larger
than at least one of the rates.
[0016]
The invention according to claim 5 of the present application is the damper for a speaker
according to claim 1, further comprising an outer connecting portion having an annular
waveform at the boundary between the flat portion and the outer circumferential waveform
portion, the flat portion and the inner circumferential waveform portion An inner connection
portion having an annular corrugation is provided at the boundary of
[0017]
The invention of claim 6 of the present application is the speaker damper according to claim 5,
wherein the groove height of the annular waveform of the outer connection portion is smaller
than the groove height of the annular waveform of the outer peripheral waveform portion, and
the annular waveform of the inner connection portion The groove height of the groove is smaller
than the groove height of the annular waveform of the inner peripheral wave portion.
[0018]
The invention according to claim 7 of the present application is the speaker damper according to
claim 5, wherein the Young's modulus of the outer connection portion and the inner connection
portion in the radial direction is the Young's modulus of the outer peripheral waveform portion
and the inner peripheral waveform portion in the radial direction. It is characterized by being
smaller than.
[0019]
The invention according to claim 8 of the present application is the damper for a speaker
according to claim 5, wherein the visco-elastic properties of the outer connecting portion and the
inner connecting portion are larger than the visco-elastic viscosities of the outer peripheral
waveform portion and the inner peripheral waveform portion. It is characterized by
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5
[0020]
The invention according to claim 9 of the present application is characterized in that, in the
speaker damper according to claim 1, a plurality of protrusions are provided on at least one of
the upper surface and the lower surface of the flat portion in order to suppress resonance of the
flat portion. It is said that.
[0021]
The invention according to claim 10 of the present application is characterized in that, in the
speaker damper according to claim 9, the protrusions are arranged radially along the annular flat
surface of the flat portion.
[0022]
The invention according to claim 11 of the present application is the damper for a speaker
according to claim 9, characterized in that the projection is a bar-like projection, and the crosssectional shape is a polygon.
[0023]
The invention according to claim 12 of the present application is the damper for a speaker
according to claim 9, wherein the projection is a linear projection formed radially on the annular
flat surface of the flat portion, and the cross-sectional shape of the linear projection is It is
characterized in that it is a polygon.
[0024]
The invention according to claim 13 of the present application is the damper for a speaker
according to claim 12, characterized in that the protrusions are alternately arranged on the
upper surface and the lower surface of the flat portion so as to be adjacent in the circumferential
direction. is there.
[0025]
The invention according to claim 14 of the present application is the damper for a speaker
according to claim 9, wherein the projection is a linear projection formed in an annular flat
surface of the flat portion, the direction and the length being random, The cross-sectional shape
of the projection is a polygon.
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[0026]
The invention according to claim 15 of the present application is the damper for a speaker
according to claim 9, wherein the projection is a quadrangular pyramid whose rhombic bottom
surface is positioned on an annular flat surface of the flat portion, and the quadrangular pyramid
is the annular flat. It is characterized by being arranged radially along the surface.
[0027]
The invention according to claim 16 of the present application is the damper for a speaker
according to claim 9, characterized in that the projection is made of any material of metal,
polymer resin and visco-elastic body.
[0028]
The invention according to claim 17 of the present application is a speaker frame, a diaphragm
in which an outer peripheral portion is vibratably held on the speaker frame to give air vibration,
and a cylindrical voice coil bobbin joined to an inner peripheral portion of the diaphragm. And a
voice coil wound around the voice coil bobbin, a magnetic circuit for applying an electromagnetic
force to the voice coil, and an outer peripheral portion is vibratably held by the speaker frame so
as to axially vibrate the voice coil bobbin. A speaker comprising: a damper, wherein the damper
is the speaker damper according to any one of claims 1 to 16.
[0029]
According to an eighteenth aspect of the present invention, there is provided a speaker frame, a
diaphragm in which an outer peripheral portion is vibratably held on the speaker frame to give
air vibration, and a cylindrical voice coil bobbin joined to an inner peripheral portion of the
diaphragm. A voice coil wound around the voice coil bobbin, a magnetic circuit for applying an
electromagnetic force to the voice coil, and an outer peripheral portion is vibratably held by the
speaker frame, at two different axial positions of the voice coil bobbin A speaker comprising first
and second dampers, the inner periphery of which is fixed and holds the voice coil bobbin in the
axial direction so that the voice coil bobbin can be vibrated in the axial direction, wherein the
first and second dampers It is a damper for speakers according to any one of claims 1 to 10,
characterized in that inner peripheral portions thereof are fixed at two different axial positions of
the voice coil bobbin. Is shall.
[0030]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A speaker and a speaker damper
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in each embodiment of the present invention will be described with reference to the drawings.
The same components as those of the conventional speaker shown in FIG. 34 are assigned the
same reference numerals and detailed explanations thereof will be omitted.
[0031]
(First Embodiment) FIG. 1 is a plan view showing a structure of a speaker damper (hereinafter
simply referred to as a damper) according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view showing the shape of the damper when it is cut so as to include
the central axis of the damper.
The damper 3A of the present embodiment is formed of an annular member so as to have a
hollow opening as shown in FIG.
The portion of the waveform which is a repetition of unevenness is formed in the inner
peripheral portion, and this is made the inner peripheral waveform portion 11.
In addition, a portion of a waveform which is a repetition of unevenness is formed in the outer
peripheral portion, and this is used as the outer peripheral waveform portion 12.
Such a concave or convex annular groove is called an annular corrugation.
[0032]
Further, a flat portion 10 having an annular flat surface parallel to the radial direction of the
damper is formed between the inner circumferential waveform portion 11 and the outer
circumferential waveform portion 12.
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8
The inner side of the inner peripheral waveform portion 11 is opened in a true circular shape so
that the voice coil bobbin 1 can be fixed.
When the damper 3A is incorporated into a speaker, as shown in FIG. 2, the vibration direction of
the voice coil bobbin 1 is taken as a Z axis, and the radial direction of the damper 3A is taken as
R.
[0033]
The effect of the damper by such a structure is demonstrated.
By providing the flat portion 10, the damper 3A does not easily expand and contract in the R
direction.
With regard to the vibration direction of the voice coil bobbin 1, the presence of the inner
circumferential waveform portion 11 and the outer circumferential waveform portion 12 makes
it easy to move the inner circumferential portion and the outer circumferential portion to which
stress is largely applied.
Therefore, the elastic fatigue of the damper material can be reduced, and the vibration in the Z
direction of the damper 3A is less likely to be disturbed.
As a result, the voice coil bobbin 1 is less likely to cause the rolling phenomenon, and a speaker
damper having excellent linearity can be obtained.
[0034]
FIG. 3 is a frequency characteristic diagram showing the vibration amplitude of the voice coil of
the speaker when a constant signal current is applied.
The horizontal axis represents frequency in logarithmic scale (log frequency), and the vertical
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axis represents relative amplitude value.
C in the figure indicates an amplitude value.
D indicates the lowest resonance frequency of the speaker, E indicates the most likely rolling
frequency of the conventional waveform damper (hereinafter referred to as rolling frequency),
and F indicates the rolling frequency when the damper of Embodiment 1 is used.
[0035]
The amplitude of the loudspeaker diaphragm generally attenuates at a rate of 12 dB per octave
above the lowest resonance frequency.
Therefore, the higher the frequency, the smaller the amplitude.
Therefore, by increasing the rolling frequency, it is possible to reduce the amount of rolling
amplitude.
Therefore, it is not necessary to narrow the magnetic gap more than necessary, and the contact
accident of the voice coil can be prevented.
As an example, a comparative example in the case where the conventional damper having the
same overall length (outside diameter size) seen from the cross section and the damper of the
first embodiment is applied to a speaker is shown in the table below and FIG. It is shown in 6.
[0036]
In the table below, the ratio of the rolling frequency to the lowest resonant frequency is Ra, the
value of the rolling frequency is fR when the lowest resonant frequency is 100 Hz, the amplitude
amount in the R direction at the rolling frequency is AR, and the maximum in the Z direction The
amplitude is AZ. Example of RafR AR AZ Conventional Example 4.82 482 Hz 100% 100%
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Embodiment 1 5.79 579 Hz 75.8% 100%
[0037]
FIG. 4 is an explanatory view showing the dimensions of a part of the voice coil bobbin and the
damper 3P of the conventional example. FIG. 5 is an explanatory view showing the dimensions of
a part of the voice coil bobbin and the damper 3A of the present embodiment. FIG. 6 is a
characteristic diagram showing the relationship between the driving force and the amount of
displacement of the inner peripheral portion of the damper 3P and the damper 3A in the Z
direction when the voice coil bobbin 1 is driven in the Z direction. From FIG. 6 and the above
table, it can be seen that the damper 3A in the embodiment 1 has an excellent effect in
suppressing the rolling phenomenon without reducing the maximum amplitude of the
diaphragm.
[0038]
In the damper 3P of FIG. 4 or FIG. 34, the number of concaves and convexes is 10 in total, while
in the damper 3A shown in FIG. 1 or 5, the number of concaves and convexes of the inner
circumferential waveform portion 11 is three. The number of concaves and convexes in the outer
peripheral waveform portion 12 is three, that is, the number of annular waveforms is six in total.
That is, without changing the outer diameter of the damper, a portion in which the number of
concaves and convexes is reduced is taken as the flat portion 10. The number of annular
waveforms may be any number, and can be arbitrarily selected in accordance with the ease of
manufacture, the linearity with respect to amplitude, and the shape of the speaker. According to
various experimental results, it has been found that the annular width W of the flat portion 10
should be equal to or greater than the groove width of the annular waveform of the outer
peripheral waveform portion or the inner peripheral waveform portion.
[0039]
Further, the material of the flat portion 10 may be made higher than the Young's modulus than
the material of the inner and outer peripheral waveform portions. For example, the flat portion
10 is made of plastic, and the inner circumferential wave portion 11 and the outer
circumferential wave portion 12 are made of cloth. The Young's modulus in the radial direction
of the flat portion may be greater than at least one of the Young's modulus in the radial direction
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of the outer circumferential wave portion and the Young's modulus in the radial direction of the
inner circumferential wave portion. In this case, since the rigidity of the flat portion 10 is
increased, the effect of suppressing the rolling phenomenon is further increased.
[0040]
Second Embodiment A damper according to a second embodiment of the present invention will
now be described. 7 is a plan view showing the structure of the damper in the present
embodiment, FIG. 8 is a sectional view taken along the line O-P in FIG. 7, and FIG. 9 is a sectional
view taken along the line OQ in FIG. The damper 3B is formed of an annular member whose
outer shape is an elliptical shape, and has an opening of a perfect circle in the same manner as
the first embodiment in order to join the voice coil bobbin 1 on the inner peripheral portion. The
damper 3B includes at least a flat portion 10A having an elliptical outer peripheral contour, an
outer peripheral waveform portion 12A having an outer peripheral contour and an inner
peripheral contour elliptical, and an inner peripheral waveform portion 11A having an outer
peripheral contour fitted to the flat portion 10A. Have. As shown in FIG. 7, the short axis
direction of the damper is S, and the long axis direction of the damper is L. As can be seen from
the comparison between FIGS. 8 and 9, the width or interval of the concave or convex of each
corrugation is particularly large in the L-axis direction.
[0041]
The effect of the damper by said structure is demonstrated. The stiffness of the elliptical damper
is governed by the shape in the minor axis direction. By setting the area in the major axis
direction of the flat portion 10A large, it is possible to suppress the rolling phenomenon without
largely changing the lowest resonance frequency of the speaker, as compared with an elliptical
damper having a normal waveform.
[0042]
10, 11, and 12 are diagrams showing other configuration examples of the damper according to
the present embodiment. 10 is a plan view of the damper 3C, FIG. 11 is a cross-sectional view of
FIG. 10 taken along the line O-P, and FIG. 12 is a cross-sectional view taken along the line O-Q of
FIG. As shown in FIG. 10, the damper 3C has a flat portion 10B, an inner peripheral waveform
portion 11B, and an outer peripheral waveform portion 12B. As described above, the minor
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12
diameter of the outer periphery and the minor diameter of the inner periphery of the flat portion
10B may be the same. Even with such a structure, the rolling phenomenon can be suppressed
without significantly changing the lowest resonance frequency of the speaker.
[0043]
Third Embodiment A damper according to a third embodiment of the present invention will now
be described. FIG. 13 is a cross-sectional view showing the structure of the damper in the present
embodiment. The damper 3D has a flat portion 10C, an inner peripheral waveform portion 11C,
and an outer peripheral waveform portion 12C. The inner connection portion 13 is formed at the
boundary between the flat portion 10C and the inner circumferential waveform portion 11C. The
outer connection portion 14 is also formed at the boundary between the flat portion 10C and the
outer peripheral waveform portion 12C. In the figure, Z indicates the vibration direction of the
voice coil when this damper 3D is used as a speaker, and R indicates the radial direction of the
damper 3D.
[0044]
The inner connection portion 13 is formed in an annular waveform having a height (depth) equal
to or less than the height (or depth) of one concave or convex groove of the inner and outer
peripheral wave portions, and is flat with the inner peripheral wave portion 11C. Connect with
the inner circumference of the part 10C. The outer connection portion 14 has an annular
waveform equal to or less than the height (or groove depth) of one concave or convex groove
portion of the inner and outer peripheral waveform portions, and connects the outer peripheral
waveform portion 12C and the outer periphery of the flat portion 10C.
[0045]
By providing the flat portion 10C, the damper 3D is unlikely to expand and contract in the R
direction, as in the embodiments described above. With respect to the Z direction which is the
vibration direction of the voice coil bobbin 1, a desired amplitude is secured by providing the
inner circumferential waveform portion 11C and the outer circumferential waveform portion
12C. Further, as shown in FIG. 36, elastic fatigue of the damper material can be reduced by
making it easy to move the portion where the stress of the flat damper is large. For this reason,
the amplitude limitation of the vibration of the inner peripheral part of damper 3D is relieved. As
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a result, the rolling phenomenon hardly occurs, and a speaker damper having excellent linearity
can be obtained. The above effects are the same as in the first embodiment.
[0046]
Further, the flat portion 10C and the inner circumferential waveform portion 11C are coupled via
the inner connection portion 13, and the flat portion 10C and the outer circumferential
waveform portion 12C are coupled via the outer circumferential connection portion 14.
Therefore, the inner peripheral waveform portion 11C and the outer peripheral waveform
portion 12C can be easily moved, and the linearity is further improved. Further, when a large
input is applied and vibrated with a large amplitude, the stress applied to the connection portion
between the flat portion and the waveform portion can be dispersed as compared with the case
where the inner connection portion and the outer connection portion are not provided. For this
reason, the durability of the damper is improved, and the effect of preventing elastic fatigue and
breakage of the connection portion can be obtained.
[0047]
Although the number of concaves or convexes of the inner connection portion 13 or the outer
connection portion 14 is two in FIG. 13, it may be any number. Further, it is preferable that the
Young's modulus in the radial direction of the outer connection portion and the inner connection
portion be smaller than the Young's modulus in the radial direction of the outer peripheral
waveform portion and the inner peripheral waveform portion. If the material of the connecting
portion is made of a material having a Young's modulus smaller than that of the inner and outer
peripheral wave portions as described above, the mobility and the linearity are further improved.
In addition, if the visco-elastic properties of the outer connecting portion and the inner
connecting portion are made of a material higher than the visco-elasticity in the radial direction
of the outer peripheral waveform portion and the inner peripheral waveform portion, strain due
to stress can be absorbed by internal loss. In this case, the durability of the damper is further
improved. Further, by selecting the material and the shape, the linearity of the damper, the
rolling suppression effect, the durability, the ease of manufacturing can be improved, and the
minimum resonance frequency of the speaker can be finely adjusted.
[0048]
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14
Fourth Embodiment Next, a damper according to a fourth embodiment of the present invention
will be described. FIG. 14 is a plan view showing the structure of the damper in the present
embodiment, and FIG. 15 is a cross-sectional view taken along the line O-P in FIG. The damper 3E
has a flat portion 10D, an inner peripheral waveform portion 11D, and an outer peripheral
waveform portion 12D. And many projection parts 15 are provided in flat part 10D. In the
present embodiment, the shape of the protrusion 15 is hemispherical, but the diameter and the
arrangement position thereof are random. Note that Z in FIG. 15 indicates the vibration direction
of the voice coil when the damper 3E is used as a speaker, and R indicates the radial direction of
the damper.
[0049]
The effect of the damper by said structure is demonstrated. By providing the flat portion 10D, the
damper 3E does not easily expand and contract in the R direction. With respect to the Z direction
which is the vibration direction of the voice coil bobbin, a desired amplitude can be secured by
providing the inner circumferential waveform portion 11D and the outer circumferential
waveform portion 12D. Further, as shown in FIG. 36, elastic fatigue of the damper material can
be reduced by making it easy to move the portion where the stress of the flat damper is large.
Therefore, the vibration of the damper 3E can not be suppressed. In addition, the rolling
phenomenon is less likely to occur, and a speaker damper with excellent linearity can be
obtained. Thus, the same effect as that of the first embodiment can be obtained.
[0050]
On the other hand, the flat portion 10D is likely to resonate at a frequency at which the width W
in the circumferential direction is a half wavelength because of the cross-sectional shape. For this
reason, resonance may impair the sound quality of the speaker. By providing the projections 15
as shown in FIGS. 14 and 15 on the flat portion 11D, the resonance points can be dispersed.
Therefore, it is possible to prevent the sound quality from being deteriorated at a specific
resonance frequency. In addition, the strength in the R direction is increased by the presence of
the protrusions, so the effect of suppressing the rolling phenomenon is further increased. In
addition, in FIG. 15, although the protrusion part 15 is provided so that it may protrude upwards,
the same effect is acquired even if it makes it protrude downward.
[0051]
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15
16-20 is a figure which shows the other structural example of the damper of this Embodiment.
FIG. 16 is a cross-sectional view showing the configuration of a damper 3F having a hollow
protrusion. The damper 3F of FIG. 16 has a flat portion 10E, an inner peripheral waveform
portion 11E, and an outer peripheral waveform portion 12E. The hemispherical shell-like
protrusions 15A may be provided on one surface of the flat portion 10E, or may be provided on
both surfaces.
[0052]
FIG. 17 is a cross-sectional view showing the configuration of a damper 3G having a projection
filled inside (hereinafter referred to as solid). The damper 3G of FIG. 17 has a flat portion 10F, an
inner peripheral waveform portion 11F, and an outer peripheral waveform portion 12F. Then,
the flat portion 10F is provided with a hemispherical protrusion 15B whose inside is filled. When
a die material is pressed by a sheet-like material having a uniform thickness to form a damper,
the inside becomes hollow as shown in FIG. When the damper is molded by injection of resin, the
inside of the projection is filled as shown in FIG. The designer can freely select the material in
consideration of the weight of the damper, the resonance suppression effect, the rolling
suppression effect, and the formability.
[0053]
FIG. 18 is a plan view showing the configuration of a damper 3H having a bar-like projection
having a triangular cross section, and FIG. 19 is a cross-sectional view taken along the line O-P of
FIG. The damper 3H shown in FIGS. 18 and 19 has a flat portion 10G, an inner peripheral
waveform portion 11G, and an outer peripheral waveform portion 12G. Then, a bar-like
projection 15C having a triangular cross section is provided on the flat portion 10G. The length,
direction, and formation position of the protrusions 15C are random as shown in FIG.
[0054]
FIG. 20 is a cross-sectional view showing the configuration of a damper 3I having a bar-like
protrusion having a rectangular cross section. The damper 3I shown in FIG. 20 has a flat portion
10H, an inner circumferential waveform portion 11H, and an outer circumferential waveform
portion 12H. The flat portion 10H is provided with a bar-like protrusion 15D having a square
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cross section. Also in this case, the linear projections 15D are randomly arranged. These barbs
may be made of a material different from that of the damper 3H or 3I and be fixed to the annular
flat surface. For example, it is also possible to integrally form the portion other than the bar-like
projections with cloth, mold the bar-like protrusions with plastic or aluminum, and attach the
bar-like protrusions to the flat portion 10H later. If the bar-like projections are made of a
material having a high Young's modulus, the effect of reinforcing the flat portion is increased,
and the rolling phenomenon suppressing effect and the resonance suppressing effect are
improved. Further, if the bar-like projections are made of a material with high viscoelasticity such
as rubber, the resonance sharpness of the flat portion can be lowered, and the resonance
suppressing effect is improved. Of course, the cross-sectional shape of the linear projections may
be semicircular or any polygonal shape.
[0055]
Fifth Embodiment Next, a damper according to a fifth embodiment of the present invention will
be described. FIG. 21 is a plan view showing the structure of the damper in the present
embodiment. 22 is an O-P cross-sectional view of FIG. 21, and FIG. 23 is an A-B cross-sectional
view of FIG. The damper 3J has a flat portion 10J, an inner peripheral waveform portion 11J, and
an outer peripheral waveform portion 12J. And the radial projection part 16 is provided in the
flat part 10J. The radial protrusions 16 are formed in a hollow stripe shape having a triangular
cross section as shown in FIG. The radial protrusions 16 are radially disposed along the radial
direction of the damper 3J as shown in FIG. In addition, Z shown in FIG. 22 shows the vibration
direction of the voice coil at the time of using this damper 3J for a speaker, R shows the radial
direction of damper 3J.
[0056]
The effect of the damper by said structure is demonstrated. By providing the flat portion 10J, the
damper 3J does not easily expand and contract in the R direction. With respect to the Z direction
which is the vibration direction of the voice coil bobbin, the place where the stress of the flat
damper is largely applied is easily moved by the inner circumferential waveform portion 11J and
the outer circumferential waveform portion 12J. For this reason, the amplitude at the time of
vibration of damper 3J is secured. As a result, it is possible to obtain a speaker damper which is
less likely to cause a rolling phenomenon and has excellent linearity. Thus, the same effect as
that of the first embodiment can be obtained.
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[0057]
On the other hand, because of the cross-sectional shape of the flat portion, it becomes easy to
resonate at a frequency that makes the width W in the circumferential direction a half
wavelength. The resonance may impair the sound quality of the speaker. By providing the radial
projections 16 on the flat portion 10J of the present embodiment, the flat portion 10J can be
reinforced to suppress resonance. Further, since the radial protrusions 16 increase the strength
in the R direction, the effect of suppressing the rolling phenomenon is increased. This effect is
similar to that of the third embodiment.
[0058]
The other structural example of a radial projection part is shown in FIGS. 24-26. In FIG. 23, the
hollow radial projections 16 are provided to project above the flat portion 10J. However, as
shown by the flat portion 10K in FIG. 24, the same effect can be obtained by projecting the radial
protrusions 16A upward and downward. Alternatively, the radial protrusions may be protruded
in both the upper and lower directions, and may be alternately arranged in the circumferential
direction.
[0059]
Further, as shown by the flat portion 10L in FIG. 25, the cross-sectional shape of the radial
projection 16B may be a hollow quadrilateral. Furthermore, as shown by the flat portion 10M in
FIG. 26, the cross-sectional shape of the radial projection 16C may be a solid triangle. These
shapes can be arbitrarily selected by the designer taking into consideration the ease of molding,
the effect of suppressing resonance of the flat portion, the effect of suppressing the rolling
phenomenon, and the weight of the damper.
[0060]
The radial projections in the present embodiment may be made of another material and fixed to
the flat portion. For example, parts other than the radial projections may be integrally formed of
cloth, and the radial projections may be formed of plastic or aluminum and attached to a flat part
later. As described above, when the radial projections are made of a material having a high
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Young's modulus, the effect of reinforcing the flat portion is increased, and the suppressing effect
of the rolling phenomenon and the suppressing effect of the resonance are improved. If the radial
projections are made of a material with high viscoelasticity such as rubber, the resonance
sharpness of the flat portion can be lowered, and the resonance suppression effect is improved.
[0061]
Another configuration example of the damper according to the present embodiment is shown in
FIGS. FIG. 27 is a plan view showing the configuration of the damper 3L. 28 is a partial
perspective view of FIG. 27, FIG. 29 is a cross-sectional view taken along the line O-P of FIG. 27,
and FIG. 30 is a cross-sectional view taken along the line A-B of FIG. The damper 3L has a flat
portion 10N, an inner peripheral waveform portion 11K, and an outer peripheral waveform
portion 12K. The flat portion 10N is provided with a quadrangular pyramidal protrusion 16D.
[0062]
As shown in FIGS. 27 and 28, the projection 16D is in the shape of a hollow square weight
having a rhombus on the bottom. Since the projection 16D having such a shape further enhances
the effect of reinforcing the flat portion, the effects of suppressing the resonance of the flat
portion 10N and suppressing the rolling phenomenon are significantly increased. In FIG. 30, the
projection 16D is provided so as to protrude upward, but may be protruded downward. Another
structural example of the protrusion is shown in FIG. In the flat portion 10P of FIG. 31, the
protrusions 16E are formed so as to alternately protrude vertically. The same effect is obtained in
this case as well.
[0063]
Sixth Embodiment Next, as a sixth embodiment of the present invention, a speaker provided with
the damper of the above embodiment will be described. FIG. 32 is a cross-sectional view of the
structure of the loudspeaker (part 1) in the present embodiment, and the same parts as those of
the loudspeaker shown in FIG. This speaker is configured to include a voice coil bobbin 1, a
diaphragm 2, a damper 3A, an edge 4, and a frame 5. The voice coil bobbin 1 is held by the
damper 3A. Then, the voice coil bobbin 1 is vibrationally supported by the frame 5 together with
the diaphragm 2. The outer peripheral portion of the diaphragm 2 is supported by the frame 5
by the rolled edge 4. A magnetic circuit is formed by the magnet 6, the yoke 7 and the plate 8. A
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desired magnetic flux density is secured in the magnetic gap 9 of the magnetic circuit. Then, the
voice coil 1 a is held in the magnetic gap 9. In the figure, Z indicates the vibration direction of the
voice coil bobbin, and R indicates the radial direction of the damper perpendicular to the
vibration direction.
[0064]
FIG. 33 is a cross-sectional view of the structure of the loudspeaker (2) in this embodiment, and
the same parts as those of the loudspeaker shown in FIG. 32 will be described with the same
reference numerals. The speaker includes a voice coil bobbin 1, a diaphragm 2, a first damper
3M, a second damper 3N, an edge 4, and a frame 5. The voice coil bobbin 1 is held by two
coaxial dampers 3M and 3N. Then, the voice coil bobbin 1 is vibrationally supported by the
frame 5 together with the diaphragm 2. The outer peripheral portion of the diaphragm 2 is
supported by the frame 5 by the rolled edge 4.
[0065]
The operation of the speaker in the above configuration will be described. When a signal current
is applied to the voice coil 1a, the voice coil bobbin 1 vibrates with a driving force proportional to
the signal current by the magnetic flux of the magnetic gap 9. The vibration is transmitted to the
diaphragm 2 and a sound is emitted.
[0066]
As shown in FIG. 34, many conventional speakers are provided with a damper having a waved
portion formed on the entire surface, but if this damper is shown in the first to fifth
embodiments, the speaker is Rolling phenomenon can be effectively suppressed. In addition to
such an effect, in the loudspeaker shown in FIG. 33, the voice coil bobbin 1 is further supported
by the first damper and the second damper, so that the effect of suppressing the rolling
phenomenon is significantly increased. Further, by limiting the upper limit value of the elastic
deformation of one of the dampers to a predetermined value, it is possible to suppress the
excessive amplitude of the diaphragm at the time of excessive input and to prevent the
performance deterioration as the speaker.
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[0067]
The two dampers may be a combination of the same dampers shown in the first embodiment, or
may be a combination of the dampers shown in the first to fifth embodiments. The designer can
freely select it while considering the suppression effect of the rolling phenomenon and the
linearity in the vibration direction.
[0068]
As described above, in the speaker damper of the present invention, the rolling phenomenon of
the diaphragm and the voice coil bobbin can be suppressed by providing the flat portion between
the outer peripheral waveform portion and the inner peripheral waveform portion. The linearity
of the vibration of the diaphragm can be realized from small amplitude to large amplitude.
[0069]
Further, by providing the projection on the flat portion of the damper, the rigidity of the flat
portion can be improved, and the resonance of the flat portion itself can be suppressed.
In this case, it is possible to prevent the deterioration of the sound quality due to the resonance
of the flat portion.
[0070]
Moreover, according to the speaker of the present invention, the rolling phenomenon can be
suppressed even when the diaphragm vibrates with a large amplitude. Therefore, the contact
accident at the time of high power driving of the voice coil is eliminated. Further, the positional
accuracy when attaching the voice coil bobbin and the damper to the magnetic circuit is relaxed,
and the manufacturing yield as a speaker is improved.
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