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JP2010258538

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DESCRIPTION JP2010258538
PROBLEM TO BE SOLVED: To provide a speaker excellent in reproduction sound quality, which
has a high connection strength between a first diaphragm, a second diaphragm, and a voice coil
bobbin constituting a vibration system and which has few peak dips in sound pressure frequency
characteristics. Do. A speaker includes a first diaphragm disposed on the front side for emitting
sound waves, and a second diaphragm disposed on the back side of the first diaphragm and
connected to the outer circumferential side of the first diaphragm on the outer circumferential
side thereof. A diaphragm, and a voice coil including a substantially cylindrical bobbin in which
the inner peripheral sides of the first diaphragm and the second diaphragm are respectively
separated and connected, and the first diaphragm is folded back from the outer peripheral end
thereof And an engagement ridge portion defining a convex ridge line portion on the front side
and defining an engagement recess on the back side of the ridge line portion, and the second
diaphragm has an outer peripheral end portion The mode frequency f2 at which the second
diaphragm is divided and vibrated is set higher than the mode frequency f1 at which the first
diaphragm is divided and vibrated. There is. [Selected figure] Figure 9
スピーカー
[0001]
The present invention relates to a speaker that uses a diaphragm that is lightweight, has high
rigidity, and has a wide piston vibration zone, and in particular, a first diaphragm disposed on the
front side that emits sound waves, and a speaker that is disposed on the back side of the first
diaphragm. A speaker having a speaker vibrating system of a double diaphragm structure
including a second vibrating plate and a bobbin of a voice coil connected to the first vibrating
plate and the second vibrating plate.
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1
[0002]
In the speaker, an assembly structure in which an inner peripheral end of a speaker diaphragm
(in particular, a cone type diaphragm) is adhered with an adhesive to a cylindrical side surface of
a cylindrical voice coil bobbin is often used.
Some conventional speakers attempt to reduce the number of assembly steps by devising this
assembly structure. In addition, in a speaker provided with a cone-shaped diaphragm or a domeshaped diaphragm, a double vibration that improves the strength of the speaker vibration system
by providing a cone-shaped diaphragm behind the diaphragm exposed to the front side. Board
structure may be adopted.
[0003]
Conventionally, for example, in a speaker in which a central portion of a diaphragm is coupled to
a voice coil embedded in a magnetic gap of a magnetic circuit, the diaphragm has two or more
sheets in which one of a half apex angle and a curvature is different. There is a speaker
characterized in that it is configured using a cone of U.S. Pat. Moreover, as a speaker of the
double diaphragm structure according to the applicant of the present invention, the respective
outer peripheral portions of two cone-shaped diaphragm base materials having different half
apex angles are adhered to each other, and the inner periphery of a common edge member The
respective inner peripheral portions of the diaphragm base are connected to the common voice
coil bobbin with a gap therebetween, and the core material is inserted in the gap between the
two diaphragm bases. There is a speaker characterized in that a diaphragm having a filled
structure is held by a frame through the edge (Patent Document 2).
[0004]
Further, in the inverted dome type speaker in which the shape of the diaphragm is a front
longitudinal cross section and the curved surface protrudes downward in a dome shape, the
diaphragm 1 is formed by injection molding mainly made of thermoplastic resin and concentric
on the back surface of the diaphragm 1 A plurality of ring-shaped ribs 15a, 15b, 15c, 15d are
provided, and the voice coil bobbin 2 is fixed to the diaphragm 1 with one of the ribs 15 as a
guide, and the voice coil bobbin 2 There is a speaker in which a ring-shaped throat 22 is
disposed between the two and the other rib of the rib group 15 (Patent Document 3).
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2
[0005]
Further, a speaker diaphragm which does not have a dual diaphragm structure according to the
applicant of the present invention has a first diaphragm portion 5, a second diaphragm portion 6
integrally formed with the first diaphragm portion 5, and a first vibration. The first diaphragm
portion 5 and the second diaphragm portion 6 are provided with a mounting portion 7 which is
provided on the back side of the joint portion between the plate portion 5 and the second
diaphragm portion 6 so as to be protruded and to which one end of the voice coil bobbin is
attached. The base material is impregnated with a thermosetting resin, and the mounting portion
7 is formed by curing the thermosetting resin (Patent Document 4).
There is also a speaker diaphragm having a base and a surface material disposed on one side of
the base and including a woven fabric of polyethylene naphthalate fibers (Patent Document 5).
These speaker diaphragms reduce the transmission loss of the driving force from the voice coil
bobbin, and particularly in the latter case, realize a speaker diaphragm excellent in the balance
between the Young's modulus and the internal loss. Can improve the S / N ratio.
[0006]
JP-A-63-155900 (FIG. 1) JP-A-62-68394 (FIGS. 1 to 3) JP-A-9-247791 (FIG. 3) Patent No.
3846497 (FIG. 1) Fig. 4) Japanese Patent Application Publication No. 2007-259261
[0007]
However, the speaker vibration system of the conventional double diaphragm structure is not
sufficient.
With the first diaphragm on the front side and the second diaphragm on the back side, the
speaker vibration system with a double diaphragm structure whose weight tends to be heavy is
generally used to enhance the reproduction efficiency of the speaker. It is necessary to reduce
the weight. In the speaker vibration system having a double diaphragm structure, if rigidity is
insufficient due to weight reduction unless the first diaphragm on the front side and the second
diaphragm on the rear side are respectively designed optimally, the respective diaphragms There
is a problem that the influence of the divided vibration mode in the above appears at a low
frequency. That is, the speaker vibration system of the double diaphragm structure in which the
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3
first diaphragm and the second diaphragm are combined including the bobbin of the voice coil
has a peak on the sound pressure frequency characteristic when the rigidity as the coupled
structure becomes low. -There is a problem that the dip becomes large and the piston vibration
area becomes narrow, which may cause the deterioration of the reproduction sound quality.
[0008]
The present invention has been made to solve the above-mentioned problems of the prior art,
and its object is to connect a first diaphragm constituting a vibration system, a second
diaphragm, and a bobbin of a voice coil. It is an object of the present invention to provide a
speaker excellent in reproduction sound quality in which the rigidity of the speaker vibration
system having the double diaphragm structure is high and the peak dip on the sound pressure
frequency characteristic is small.
[0009]
The speaker according to the present invention includes a substantially cone-shaped first
diaphragm disposed on the front side for emitting a sound wave, and a diaphragm disposed on
the back side of the first diaphragm and connected to the outer periphery of the first diaphragm
on the outer circumferential side And a voice coil including a substantially cylindrical bobbin in
which inner peripheral sides of the first diaphragm and the second diaphragm are respectively
separated and connected, and the first diaphragm is The second diaphragm has an engagement
ridge portion extended so as to be folded back from the outer peripheral end and defining a
convex ridge on the front side and defining an engagement recess on the rear side of the ridge.
The frequency f2 of the mode in which the outer peripheral side of the second diaphragm is
divided and vibrates and the outer peripheral side of the first diaphragm is divided and vibrated.
The frequency is set higher than the frequency f1 of the mode.
[0010]
Preferably, in the speaker according to the present invention, the Young's modulus E2 of the
second diaphragm is smaller than the Young's modulus E1 of the first diaphragm, or the internal
loss δ2 of the second diaphragm is that of the first diaphragm. It is larger than the internal loss
δ1, or the specific gravity 22 of the second diaphragm is smaller than the specific gravity 11 of
the first diaphragm.
[0011]
Preferably, in the speaker of the present invention, the first diaphragm has a substrate formed by
impregnating a base material including a woven or non-woven fabric made of fibers with a
thermosetting resin containing an unsaturated polyester resin, (2) The vibration plate has a base
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having a paper material formed by papermaking of paper fibers as a base material.
[0012]
In addition, preferably, in the speaker according to the present invention, the first diaphragm and
the second diaphragm have a base having a paper material formed by paper-making paper fibers
as a base material.
[0013]
More preferably, in the speaker according to the present invention, the first diaphragm further
includes a surface material adhered to the front side of the base, and the surface material is any
of plain weave, twill weave, and forceps weave. It comprises a woven fabric of silk fibers or
polyethylene naphthalate fibers.
[0014]
Preferably, in the speaker according to the present invention, the outer periphery coupled to the
frame, the inner periphery coupled to the outer periphery of the first diaphragm or the second
diaphragm, and the outer periphery and the inner periphery are defined. It further comprises an
edge having a supported movable portion and an annular recess with which the engagement
ridge of the first diaphragm engages.
[0015]
Preferably, in the speaker according to the present invention, the frame is connected to a damper
in which an inner peripheral end is connected to a bobbin of a voice coil, a frame in which an
outer peripheral part of an edge and an outer peripheral end of the damper are connected, And a
magnetic circuit having a magnetic air gap in which the coil of the coil is disposed.
[0016]
Hereinafter, the operation of the present invention will be described.
[0017]
The speaker according to the present invention includes a substantially cone-shaped first
diaphragm disposed on the front side for emitting a sound wave, and a diaphragm disposed on
the back side of the first diaphragm and connected to the outer periphery of the first diaphragm
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on the outer circumferential side And a voice coil including a substantially cylindrical bobbin in
which inner peripheral sides of the first diaphragm and the second diaphragm are respectively
separated and connected.
Preferably, in the speaker according to the present invention, the outer periphery coupled to the
frame, the inner periphery coupled to the outer periphery of the first diaphragm or the second
diaphragm, and the outer periphery and the inner periphery are defined. A frame having an edge
having a supported movable portion, a damper whose inner peripheral end is connected to the
bobbin of the voice coil, a frame where the outer peripheral portion of the edge and the outer
peripheral end of the damper are connected, And a magnetic circuit having a magnetic air gap in
which a coil of the voice coil is disposed.
Therefore, the speaker of the present invention is an electrodynamic speaker having a speaker
vibration system with a double diaphragm structure.
[0018]
The first diaphragm is extended so as to be folded back from its outer peripheral end, and has an
engaging ridge portion which defines a convex ridge on the front side and defines an
engagement recess on the rear side of the ridge.
The engagement flange portion of the first diaphragm enhances the strength on the outer
peripheral side of the first diaphragm and engages with the annular recess of the edge.
In addition, the second diaphragm has an engagement portion at its outer peripheral end that
engages with the engagement recess of the first diaphragm, and the first adhesive and the second
vibration are applied by the first adhesive applied thereto. The board is connected.
Therefore, the first diaphragm and the second diaphragm are separated from each other on the
inner peripheral side thereof and coupled to the bobbin of the substantially cylindrical voice coil,
and thus constitute a speaker vibration system that is a strong structure having a substantially
triangular cross section. Do.
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The first diaphragm is formed integrally with the base on the inner peripheral side of the
substantially cone-shaped base, with the connecting part connected to the end of the bobbin and
the central part covering the inner peripheral side of the connecting part. It may be in the form
of a dome, or in the form of a cone integrated with a dust cap.
[0019]
Here, in the second diaphragm, the frequency f2 of the lowest mode in which the outer
peripheral side divides and vibrates is set higher than the frequency f1 of the lowest mode in
which the outer peripheral side of the first diaphragm divides. It is a diaphragm whose rigidity is
higher than that of the first diaphragm.
Further, Young's modulus E2 of the second diaphragm is smaller than Young's modulus E1 of the
first diaphragm, or internal loss δ2 of the second diaphragm is lower than internal loss δ1 of
the first diaphragm. The specific gravity ρ2 of the second diaphragm is set larger than the
specific gravity 11 of the first diaphragm.
Specifically, the first diaphragm is a speaker diaphragm in which a substrate is formed by
impregnating a thermosetting resin containing an unsaturated polyester resin into a base
material including a woven or non-woven fabric made of fibers, or a paper It is a speaker
diaphragm in which a substrate having a base material made of paper material formed by making
paper into a base material is formed, preferably a silk fiber or a silk fiber made of plain weave,
twill weave or satin weave. It further comprises a facing comprising a woven fabric of
polyethylene naphthalate fibers on the front side.
The second diaphragm is a speaker diaphragm in which a base having a paper material formed
by paper-making of paper fibers as a base material is molded.
[0020]
In the speaker vibrating system having a double diaphragm structure according to the present
invention, the outer peripheral edge portion of the second diaphragm defined as a portion to
which the inner peripheral portion of the edge is connected is the second diaphragm between the
first diaphragm and the second diaphragm The separation space is formed such that the distance
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7
separating from the engagement portion toward the inner circumferential side increases. By
providing this separated space, the outer peripheral side of the first diaphragm that emits sound
waves on the front side is reinforced by the outer peripheral side of the more rigid second
diaphragm, which has a higher frequency at which divided vibration occurs from the first
diaphragm. As a result, it is possible to push up the frequency of the mode in which the outer
peripheral side starts divided vibration to a higher frequency, and to expand the piston vibration
region. In addition, when the second adhesive different from the first adhesive is applied and
filled in the separated space defined between the first diaphragm and the second diaphragm, the
inside is relatively soft. Since the large loss second adhesive suppresses the divided vibration of
the first diaphragm and the second diaphragm, it is possible to realize a speaker excellent in
reproduced sound quality with less peak dip in sound pressure frequency characteristics.
[0021]
The speaker according to the present invention can provide a speaker excellent in reproduction
sound quality, having high rigidity of a speaker vibration system having a double diaphragm
structure and less peak-dip on sound pressure frequency characteristics.
[0022]
It is a figure explaining the speaker 1 by preferable embodiment of this invention.
(Example 1) It is a principal part enlarged view explaining the speaker vibration system of the
speaker 1 of this invention. (Example 1) It is a principal part enlarged view explaining the
speaker vibration system of the speaker 100 of a comparative example. (Comparative example) It
is a graph explaining the speaker diaphragm outer periphery intensity | strength of the speaker 1
of this invention, and the speaker 100 of a comparative example. (Example 1, Comparative
Example 1) It is a graph explaining the acoustic characteristic of the speaker 1 of this invention
and the speaker 100 of a comparative example. (Example 1, Comparative Example 1) FIG. 7 is an
enlarged view of an essential part for explaining a speaker vibration system of a speaker 21
according to another example of the present invention. (Embodiment 2) FIG. 7 is an enlarged
view of a main part for explaining a speaker vibration system of a speaker 22 according to
another embodiment of the present invention. (Embodiment 3) FIG. 14 is an enlarged view of a
main portion for explaining a speaker vibration system of a speaker 23 according to another
embodiment of the present invention. (EXAMPLE 4) It is a figure explaining the speaker 31 by
other preferable embodiment of this invention. (Example 5) FIG. 15 is a view for explaining a
speaker 41 according to another preferred embodiment of the present invention. (Example 6)
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[0023]
Hereinafter, although the speaker by the preferred embodiment of the present invention is
explained, the present invention is not limited to these embodiments.
[0024]
FIG. 1 is a schematic cross-sectional view of a speaker 1 according to a preferred embodiment of
the present invention.
Further, FIG. 2 is an enlarged view of a main part for explaining a speaker vibration system of the
speaker 1, and is a cross-sectional view in which an X portion illustrated in FIG. In addition, as
described later, a part of the structure of the speaker 1, an internal structure, and the like are
omitted. Further, in the speaker 1, the upper side of the speaker diaphragm 5 as the first
diaphragm to be exposed is the front side, and the lower side to which the magnetic circuit 10 is
attached is the rear side.
[0025]
The speaker 1 is an electrodynamic speaker having a caliber of about 15 cm and provided with a
bullet-like equalizer 9, and is provided with a substantially cone-shaped first diaphragm 5
disposed on the front side for emitting sound waves, and a first diaphragm A substantially coneshaped second diaphragm 6 which is disposed on the back side of the fifth side and is connected
to the outer circumferential side of the first diaphragm 5 on the outer circumferential side, and
the inner circumferential sides of the first diaphragm 5 and the second diaphragm 6 A voice coil
bobbin 2 having a substantially cylindrical shape, which is separated and connected, and a voice
coil 3 wound around the lower end portion of the voice coil bobbin 2 constitute a speaker
vibration system having a double diaphragm structure. The voice coil bobbin 2 and the voice coil
3 are disposed in the magnetic air gap of the magnetic circuit 10 fixed to the frame 8 and
displace in the magnetic air gap according to the input signal so that the speaker of the double
diaphragm structure of the speaker 1 Drive the vibration system. Further, the speaker vibration
system of the double diaphragm structure of the speaker 1 is supported so as to be vibrated in
the vertical direction as illustrated by the damper 4 and the edge 7 whose outer peripheral side
is fixed to the frame 8.
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[0026]
The voice coil bobbin 2 is made of, for example, aluminum having a material thickness of 0.05
mm, the voice coil 3 is wound around the lower end thereof, and the reinforcing paper is wound
around the outer curved surface where the voice coil 3 is not wound. In general, they are formed
in a cylindrical shape having a diameter of about 39.0 mm. The voice coil bobbin 2 may also be
formed of polyimide film, duralumin, silter, capton or the like. A tinsel wire (not shown) is
soldered and fixed to the voice coil 3, and the other end of the tinsel wire is fixed so as to be
conductive to a terminal (not shown) fixed to the frame 8. Voice signal current is supplied to the
voice coil 3 through these terminals and the tinsel wire.
[0027]
The inner diameter end of the damper 4 is connected to the outer curved surface of the voice coil
bobbin 2 by an adhesive. The outer diameter end of the damper 4 is adhesively fixed to the
damper fixing portion of the frame 8. The damper 4 may be an annular ring-shaped corrugation
damper which is formed by impregnating a resin such as a phenol resin with a flexible fiber
woven fabric as a base material, and is formed of another material. It is also good. For example, it
may be a butterfly damper which has an arm connecting the inner ring and the outer ring and is
formed of metal or resin. The frame 8 is a frame of aluminum die-cast formed in a basket shape,
and is connected to the magnetic circuit 10 by a plurality of screws. The frame 8 may be an iron
plate frame press-formed into a basket shape corresponding to the speaker vibration system
having a double diaphragm structure.
[0028]
The magnetic circuit 10 has an annular top plate 11 fixed to the frame 8 and a pole which has a
cylindrical pole and a center pole and a flat underplate inserted in a circular hole formed at the
center of the top plate 11. 12 and an annular magnet 13. The top plate 11 and the pole 12 form
a circular magnetic air gap having a uniform width. The magnet 13 is bonded so as to be held
between the top plate 11 and the under plate of the pole 12. The magnet 13 of the present
embodiment is a ferrite based magnet, and may be an Nd-Fe-B based rare earth magnet having a
larger residual magnetization and coercivity, and having a smaller volume or a stronger
coercivity. In the magnetic circuit 10 of the present embodiment, the cancel magnet 14 is
magnetized and coupled on the back side of the underplate of the pole 12 so as to have magnetic
polarity in the reverse direction to the magnet 13, and the back side of the cancel magnet 14.
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And a cover 15 magnetically shielded to cover the entire magnetic circuit 10.
[0029]
The equalizer 9 is a shell-shaped member formed of an alloy containing aluminum in the present
embodiment, and is formed on the center pole of the pole 12 of the magnetic circuit 10 so that
the pointed end side protrudes from the neck portion of the first diaphragm 5. It is connected
and fixed. The equalizer 9 fills in the cylindrical internal space formed by the voice coil bobbin 2
and a part of the space surrounded by the first diaphragm 5 having a substantially cone shape,
eliminates air occupying these spaces, and prepares directivity characteristics. Flatten the sound
pressure frequency characteristics. The equalizer 9 connected to the magnetic circuit 10 is
preferably formed of a nonmagnetic member such as brass or resin.
[0030]
The first diaphragm 5 is a diaphragm exposed on the front side when the speaker 1 having the
speaker vibration system having a double diaphragm structure is viewed from the front, and the
first diaphragm 5 is substantially defined by a curved line whose cross-sectional shape is
smoothly continuous. The diaphragm is a cone-shaped diaphragm, and has a substantially coneshaped diaphragm portion 5a and an engaging flange 5b extended so as to be folded back from
the outer peripheral end. The substantially cone-shaped diaphragm portion 5a has an inner
diameter of about 39.5 mm in diameter, an outer diameter of about 113.5 mm in diameter, and a
height of about 26.8 mm. The engagement collar 5b having a length of about 1.5 mm defines a
convex ridge 5c on the front side and an engagement recess 5d on the back of the ridge 5c, as
shown in FIG. Do. The inner diameter end of the first diaphragm 5 is connected to the outer
curved surface of the voice coil bobbin 2 by an acrylic adhesive.
[0031]
The first diaphragm 5 of the present embodiment is a base formed by impregnating a
thermosetting resin with a base material which is a laminate including a woven fabric layer or a
non-woven fabric layer made of inorganic fibers or natural fibers (diaphragm portion 5a , An
engagement flange 5b, a ridge 5c, and an engagement recess 5d. And a facing 5e adhered to the
front side of the base. Specifically, the substrate is obtained by laminating two layers of nonwoven fabric of Technora fiber, impregnating the unsaturated polyester resin, and hot pressing.
10-05-2019
11
Unsaturated polyester has a high curing rate and a low curing temperature, so that the substrate
can be produced by short-time hot press molding. In addition, the surface material 5e is obtained
by applying a thermoplastic adhesive to this substrate and drying it, and a woven fabric of silk
fibers of satin weave is made to be integrated by heat press forming. The woven fabric of satinwoven silk fibers forming the surface material 5e has silk raw yarns of 21/2 d 129 yarns / cm
and weft yarns 21/2 d 53 yarns / cm, and the composition ratio of warp yarns to weft yarns is 2.
It was 43 and was made with 2 steps and 5 pieces of satin weave.
[0032]
As a result, the first diaphragm 5 of this embodiment has the following physical properties, and
the frequency f1 of the lowest mode in which the outer peripheral side of the single first
diaphragm 5 is divided and vibrated is set to about 3.5 kHz. ing. (Example 1): 1st diaphragm 5
thickness t1 0.3 mm weight 3.8 g basis weight 428 g / m <2> Young's modulus E11 (transverse
direction) 6.4E + 9Pa Young's modulus E12 (latitude direction) 5.5E + 9Pa internal loss tan δ1
0.1 Density (specific gravity) 11 1.2 g / cm <3>
[0033]
The second diaphragm 6 is a diaphragm that hides on the rear side when the speaker 1 having
the double diaphragm structure and the speaker vibration system is viewed from the front, and
the first diaphragm 5 has a smoothly continuous sectional shape. Is a substantially cone-shaped
diaphragm defined by a different R curve and a straight line, and as illustrated in FIG. 2, the
substantially cone-shaped diaphragm portion 6a and the outer peripheral end portion of the first
diaphragm 5 are And an engaging portion 6b engaged with the engaging recess 5d. The
substantially cone-shaped diaphragm portion 6a has an inner diameter of about 39.5 mm in
diameter, an outer diameter of about 111.5 mm, and a height of about 31.2 mm. The inner
diameter end of the second diaphragm 6 is connected to the outer curved surface of the voice
coil bobbin 2 by an acrylic adhesive so as to be separated from the inner diameter end of the first
diaphragm 5.
[0034]
The second diaphragm 6 of the present embodiment has a paper base formed by papermaking,
and a plurality of through holes are concentrically arranged in the vicinity of the inner peripheral
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end of the diaphragm portion 6a, It is formed. The Young's modulus E2 of the second diaphragm
6 is smaller than the Young's modulus E11 to E12 of the first diaphragm 5, and the internal loss
δ2 of the second diaphragm 6 is the internal loss δ1 of the first diaphragm 5. The specific
gravity 22 of the second diaphragm 6 is set smaller than the specific gravity 11 of the first
diaphragm 5.
[0035]
As a result, the second diaphragm 6 of this embodiment has the following physical properties,
and the frequency f2 of the lowest mode in which the outer peripheral side of the single second
diaphragm 6 is divided and vibrated is set to about 4.0 kHz. ing. (Example 1): Second diaphragm
6 thickness t2 0.5 mm weight 2.2 g basis weight 257 g / m <2> Young's modulus E2 2.37 E + 9
Pa internal loss tan δ2 0.02 density (specific gravity) 22 0.5 g / cm < 3>
[0036]
The edge 7 is an annular shape or a ring-shaped corrugation edge that vibratably supports a
speaker vibration system having a double diaphragm structure, and an outer peripheral portion 7
a adhesively fixed to an edge fixing portion of the frame 8; An inner peripheral portion 7b
connected to the outer peripheral side of the second diaphragm 6 from the back side, a movable
support portion 7c forming a corrugation between the outer peripheral portion 7a and the inner
peripheral portion 7b, and a corrugation of the movable support portion 7c And an annular
recess 7d engaged with the engagement flange 5b of the first diaphragm 5 from the front side on
the inner peripheral side. The edge 7 of this embodiment is formed by pressure heating a suedelike artificial leather made of ultrafine fibers of polyester having flexibility, and a paper gasket 7e
is adhered to the front side of the outer peripheral portion 7a. ing. The support movable portion
7c of the edge 7 of the present embodiment has a corrugation in which the height of the peak
portion which is convex forward becomes smaller as going from the outer peripheral side to the
inner peripheral side.
[0037]
As shown in FIG. 2, at the outer peripheral end of the diaphragm portion 5a of the first
diaphragm 5, an engagement collar 5b including a base material or a thermosetting resin is
formed. The engagement flange portion 5b functions as a rib that reinforces the diaphragm
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13
portion 5a at the outer peripheral end of the diaphragm portion 5a to enhance the strength on
the outer peripheral side, and on the opposite side of the diaphragm portion 5a to the
substantially cone shape. Since it is formed as a folded ridge portion, a convex ridge portion 5c is
defined on the front side, and an engagement recess 5d is defined on the back side of the ridge
portion 5c. In the case of the speaker 1 of the present embodiment, the second diaphragm 6 has
an engagement portion 6 b at its outer peripheral end that engages with the engagement recess
5 d of the first diaphragm 5, and the edge 7 Since the inner circumferential portion 7b of the first
diaphragm 5 is adhesively fixed, the engagement flange 5b of the first diaphragm 5 engages with
the annular recess 7d of the support movable portion 7c formed by the corrugation of the edge
7.
[0038]
That is, in the speaker 1 of the present embodiment, in the step of bonding the outer peripheral
end of the first diaphragm 5 to the vibration system formed by the second diaphragm 6 and the
edge 7, the engagement flange 5 b of the first diaphragm 5 is Can be bonded to the voice coil
bobbin 2 and the second diaphragm 6 without tilting the first diaphragm 5 by engaging the
annular recess 5 d formed by the corrugation of the edge 7. The second diaphragm 6 has an
engaging portion 6 b at its outer peripheral end that engages with the engaging recess 5 d of the
first diaphragm 5. Therefore, when the first adhesive Ad 1 is applied to the second diaphragm 6,
the first diaphragm 5 is And the second diaphragm 6 are connected. As shown in FIG. 1, the first
diaphragm 5 and the second diaphragm 6 are separated from each other at their inner peripheral
sides and connected to the voice coil bobbin 2 having a substantially cylindrical shape, so that a
strong structure having a substantially triangular cross section Constitute a speaker vibration
system having a double diaphragm structure.
[0039]
Further, in the speaker vibration system of the double diaphragm structure of the speaker 1 of
the present embodiment, the outer peripheral edge portion of the second diaphragm 6 defined as
a portion to which the inner peripheral portion 7 b of the edge 7 is connected is the first
diaphragm Between the space 5 and the space 5, a separation space Y is formed in which the
distance separating from the engagement portion 6b of the second diaphragm 6 toward the inner
circumferential side becomes large. The separation space Y is a triangular space having a sharp
cross section defined between the back surface of the first diaphragm 5 and the front surface of
the second diaphragm 6 as illustrated in FIG. By providing this separated space Y, the outer
peripheral side of the second diaphragm 6, which is higher in frequency at which the outer
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peripheral side of the first diaphragm 5, which radiates sound waves on the front side, is divided
by the first diaphragm 5, is reinforced. Structure is realized.
[0040]
In the case of the present embodiment, the first adhesive Ad1 applied to the engagement recess
5d of the first diaphragm 5 and the engagement portion 6b of the second diaphragm 6 engaged
therewith is a rubber adhesive. The adhesive has a relatively high Young's modulus after curing
and a high hardness and hardness, and an internal loss is small. Further, in the case of the
present embodiment, the second adhesive Ad2 different from the first adhesive Ad1 is applied to
the separation space Y defined between the first diaphragm 5 and the second diaphragm 6 Be
filled. The second adhesive Ad2 is an acrylic resin emulsion adhesive, and is an adhesive having a
relatively small Young's modulus after curing of the adhesive, a small hardness and softness, and
a large internal loss. For example, in the case of the present example, the first adhesive Ad1 has a
Young's modulus of 7.3E + 8 Pa after the adhesive is cured, and an internal loss of 0.161 after
the adhesive is cured. Hardness is about 27 points with a type A durometer conforming to K
6253. On the other hand, the second adhesive Ad2 has a Young's modulus of 6.5 E + 7 Pa after
the adhesive is cured, and an internal loss of 0.30 and a hardness of about 8 points after the
adhesive is cured. . That is, the first adhesive Ad1 is a harder adhesive than the second adhesive
Ad2. The first adhesive Ad1 and the second adhesive Ad2 are preferably separately applied so as
not to be mixed.
[0041]
FIG. 3 is an enlarged view of a main part illustrating a speaker vibration system of the speaker
100 of the comparative example. The speaker 100 of the comparative example is an
electrodynamic speaker in which a portion illustrated as a cross-sectional view enlarged in FIG. 3
has a speaker vibration system of a double diaphragm structure different from the speaker 1 of
the present embodiment. The speaker vibration system of the speaker 100 of the comparative
example is configured of a first diaphragm 50, a second diaphragm 60, and an edge 70.
Accordingly, illustration and description of the voice coil bobbin 2, the voice coil 3, the damper 4,
the frame 8, the equalizer 9 and the magnetic circuit 10 which are common to each other will be
omitted.
[0042]
10-05-2019
15
The first diaphragm 50 is a diaphragm exposed on the front side when the speaker 100 of the
comparative example is viewed from the front, and is a substantially cone-shaped diaphragm
whose cross-sectional shape is defined by a smoothly continuous curve, It has the diaphragm
part 50a of substantially cone shape, and the engagement collar part 50b extended so that it may
return from the outer peripheral end part. The engagement collar portion 50b defines a convex
ridgeline portion 50c on the front side, and defines an engagement recess 50d on the back side
of the ridgeline portion 50c. The inner diameter end of the first diaphragm 50 is connected to
the outer curved surface of the voice coil bobbin 2 with an adhesive. Further, as in the first
diaphragm 5 of the previous embodiment, the first diaphragm 50 has a thermosetting resin on a
base material that is a laminate including a woven fabric layer or a non-woven fabric layer made
of inorganic fibers or natural fibers. It is obtained by laminating two layers of a non-woven fabric
of Technora fiber, including a base material impregnated and formed, and a surface material 50e
adhered to the front side of the base material, and impregnating an unsaturated polyester resin
and hot pressing it. .
[0043]
The second diaphragm 60 is a diaphragm hidden behind when the speaker 100 of the
comparative example is viewed from the front, and is defined by an R curve and a straight line
different from the first diaphragm 50 whose cross-sectional shape is smoothly continuous. , And
is engaged with the substantially cone-shaped diaphragm portion 60a and the outer peripheral
end of the diaphragm portion 60a engaged with the engagement recess 50d of the first
diaphragm 50, as shown in FIG. And a portion 60b. The inner diameter end of the second
diaphragm 60 is connected to the outer curved surface of the voice coil bobbin 2 so as to be
separated from the inner diameter end of the first diaphragm 50 by an adhesive. Further, the
second diaphragm 60 has a paper base formed by papermaking.
[0044]
The edge 70 is an annular corrugation edge that vibratably supports the speaker vibration
system having a double diaphragm structure, and the outer peripheral portion 70 a adhesively
fixed to the edge fixing portion of the frame 8, and the second diaphragm 60 On the outer
peripheral side of the inner peripheral portion 70b connected from the back side, the movable
support portion 70c forming a corrugation between the outer peripheral portion 70a and the
inner peripheral portion 70b, and the innermost surface of the corrugation of the movable
support portion 70c And an annular recess 70d engaged with the engagement flange 50b of the
10-05-2019
16
first diaphragm 50 from the side. The edge 70 of the comparative example is formed by pressure
heating a suede-like artificial leather made of ultrafine fibers of polyester having flexibility, and a
paper gasket 70e is adhered to the front side of the outer peripheral portion 70a. There is. In
addition, the support movable portion 70c of the edge 70 of the comparative example has a
corrugation in which the height of the peak portion which is convex forward as going from the
outer peripheral side to the inner peripheral side does not change.
[0045]
However, in the speaker vibration system of the double diaphragm structure of the speaker 100
of the comparative example, the outer peripheral edge portion of the second diaphragm 60
defined as the portion to which the inner peripheral portion 70 b of the edge 70 is connected is
the first diaphragm 50. And the adhesive, and the separation space Y is not formed between the
first diaphragm 50 and the first embodiment. That is, since the first diaphragm 50 and the
second diaphragm 60 are in close contact with each other and connected, the inner peripheral
portion 70b of the edge 70 is connected on the inner peripheral side of the outer peripheral edge
of the second diaphragm 60 In the non-portions, the space Y 'as illustrated in FIG. 3 is formed,
which increases in the distance from the engaging portion 60b of the second diaphragm 60
toward the inner circumferential side. In the speaker vibration system of the double diaphragm
structure of the speaker 100 of the comparative example, although the material having the same
configuration as the double diaphragm structure of the speaker 1 of the previous embodiment is
used, the first diaphragm 50 and the first diaphragm (2) Since the shape is different so that the
outer peripheral edge of the diaphragm 60 is in close contact with a wide area, the rigidity of this
part is insufficient and the part becomes easily bendable. That is, the outer peripheral portion
approaches flat and becomes heavy and divided and vibrates. As a result, the piston vibration
area is narrowed.
[0046]
FIG. 4 is a graph for explaining the peripheral strengths of the speaker diaphragms of the
speaker 1 of the present example and the speaker 100 of the comparative example. The speaker
vibration system of the double diaphragm structure constituted by the voice coil bobbin 2 and
the first diaphragm 5 and the second diaphragm 6 is fixed at the point a0 shown in the cross
sectional view of FIG. When weighting is given, the horizontal axis of the graph of FIG. 3 shows
the absolute value of static weight, and the vertical axis shows the absolute value of
displacement. In the first embodiment, UP is displaced in the upward direction, and DOWN is
displaced in the downward direction. The two trajectories do not largely deviate, and the
10-05-2019
17
symmetry in the vertical direction can be secured. When these trajectories are averaged, the
static load necessary for displacing the point a1 of the loudspeaker vibration system of the first
embodiment by 1 mm while fixing the point a0 is calculated to be about 52.0 kgf. On the other
hand, in the case of the comparative example 100, the deviation of the two trajectories becomes
large when displaced upward or downward, and the symmetry in the vertical direction is
reduced. In addition, when these trajectories are averaged, the static load required to displace
point a1 of the speaker vibration system of Comparative Example 100 by 1 mm while fixing
point a0 is calculated to be about 47.1 kgf Compared to the case of Example 1, it is about 10.4%
lower. As described above, the loudspeaker vibration system of the loudspeaker 1 of the present
embodiment can increase the peripheral strength of the loudspeaker diaphragm compared to the
conventional double diaphragm structure as the comparative example 100.
[0047]
FIG. 5 is a graph for explaining the acoustic characteristics of the speaker 1 of the present
embodiment and the speaker 100 of the comparative example. In the double diaphragm
structure of the speaker 1 of the present embodiment, the frequency fh of the lowest mode which
is the first mode in which the outer peripheral side starts divided vibration is about 4.2 kHz, and
at frequencies lower than that, the first vibration The plate 5 and the second diaphragm 6 are in
piston oscillation. The speaker vibration system of the double diaphragm structure forming the
separation space Y of the speaker 1 of the present embodiment has a frequency f1 of a mode in
which the outer peripheral side of the first diaphragm 5 starts divided vibration, and the outer
peripheral side is higher The second vibration plate 6 having the mode frequency f2 can be
pushed up to a higher frequency (about 4.2 kHz in this embodiment) to widen the piston
vibration area. On the other hand, in the double diaphragm structure of the speaker 100 of the
comparative example, the frequency fh of the first mode in which the outer peripheral side starts
divided vibration is about 3.2 kHz, and the first diaphragm 50 and the second diaphragm 60 are
pistons The vibrating area is narrow.
[0048]
In a speaker vibration system that does not have a general double diaphragm structure, there is a
problem that the resonance peak becomes sharper and larger if the cone shape is made deeper
or a high rigidity material is used, and the speaker diaphragm is damped. In the case of
suppressing the peak of this resonance by using a material having a high rate, there is a problem
that it is difficult to achieve the compatibility with the rigidity for realizing a sufficient piston
regeneration zone. In the speaker 1 having the speaker vibration system of the double diaphragm
10-05-2019
18
structure, the basic characteristic is mainly determined by the sound wave radiated from the first
diaphragm 5, so that the region where the first diaphragm 5 vibrates is expanded Preferably, the
second diaphragm 6 is connected to the second diaphragm 6. At that time, since the upper limit
of the piston region is determined by the frequency of the mode in which the outer peripheral
side which is the lowest resonance mode of the first diaphragm 5 starts divided vibration, it is
desired to extend this to a high frequency as much as possible.
[0049]
However, in the double diaphragm structure of the speaker 1 of the present embodiment, it is
possible to achieve both the high rigidity and the high attenuation rate. The first diaphragm 5 is
made of a rigid material capable of securing a sufficient piston regeneration zone, and the second
diaphragm 6 has a loss capable of sufficiently suppressing the mode in which the outer
peripheral side of the first diaphragm 5 starts divided vibration. It is preferable to use a
lightweight material with a high internal loss value. The Young's modulus E2 of the second
diaphragm 6 is smaller than the Young's modulus E1 of the first diaphragm 5, or the internal loss
δ2 of the second diaphragm 6 is compared to the internal loss δ1 of the first diaphragm 5
Preferably, the specific gravity 22 of the second diaphragm 6 is smaller than the specific gravity
11 of the first diaphragm 5. Therefore, in the speaker 1 having the speaker vibration system of
the double diaphragm structure, a diaphragm having a cone-shaped base whose base material is
a paper material formed by forming paper fibers in the second diaphragm 6 is adopted.
[0050]
In addition, as a base material which comprises the base | substrate of the 1st diaphragm 5,
according to a use and the objective, arbitrary appropriate woven or nonwoven fabrics and
arbitrary appropriate thermosetting resin may be employ | adopted. The substrate may be a
woven fabric or a non-woven fabric alone, or may be a laminate having a plurality of non-woven
fabrics, or a laminate of a woven fabric and a non-woven fabric. The non-woven fabric typically
includes para-aramid fibers, meta-aramid fibers, rayon fibers, cotton fibers, ultra-high strength
polyethylene fibers, polyarylate fibers and the like. Examples of the woven fabric include
polytrimethylene terephthalate and polyethylene naphthalate (PEN) fibers. The woven or nonwoven fibers may be natural fibers or inorganic fibers as described above.
[0051]
10-05-2019
19
Further, like the first diaphragm 5 of the present embodiment, the surface material 5 e may or
may not be provided. In the surface material 5e, the woven fabric having anisotropy is a plain
weave, twill weave, twill weave, satin weave, satin weave, satin weave, in which the size ratio of
the warp and weft of the woven fabric is about 1.2 or more. In any of the woven fabrics of the
above, Young's modulus changes largely depending on the background, and in the first
diaphragm 5 provided with the surface material 5e, the resonance frequency in the high region is
dispersed, and the sound pressure frequency characteristic tends to be flat. Also, the feeling of
high frequency sound is eliminated and it becomes very easy to hear. The anisotropically woven
fabric forming the surface material 5e is a woven fabric of twill (shrink) weave or tweezers
(tweezers) weave whose size ratio of the warp and weft of the woven fabric is about 1.2 or more.
And at least at least silk fibers (including silk raw yarn and silk spinning), cotton fibers, wool
fibers, polyester fibers, polyethylene naphthalate fibers, nylon fibers, aramid fibers, acrylic fibers,
polylactic acid fibers, glass fibers and carbon fibers It is sufficient if it contains one fiber. Also, in
the case of a satin weave, the warps are dense relative to the plain weave and twill weave and the
weave points are scattered, so a smooth and glossy appearance is obtained, so it is placed on the
front side. It is suitable for the surface material 5e of the first diaphragm 5 having a substantially
cone shape.
[0052]
Further, in the speaker 1 of the present embodiment, the separation space Y defined between the
first diaphragm 5 and the second diaphragm 6 constituting the double diaphragm structure is
different from the first adhesive Ad1 in the first embodiment. (2) Since the adhesive Ad2 is
applied and filled, the second adhesive Ad2 having a large internal loss suppresses the divided
vibration of the first diaphragm 5 and the second diaphragm 6, and further, the peak · on the
sound pressure frequency characteristic It is possible to realize a speaker excellent in
reproduction sound quality with less dip and less harmonic distortion. The first adhesive Ad1 and
the second adhesive Ad2 differ not only in the constituent components but also in the value of
Young's modulus after curing and also in the value of internal loss. In order to enhance the
rigidity of the speaker vibration system of the double diaphragm structure of the present
embodiment and to suppress the division vibration, the hardness after the second adhesive Ad2
is relatively cured compared to the first adhesive Ad1 is low. It is desirable that it is soft and has
a small value of Young's modulus and a large value of internal loss.
[0053]
10-05-2019
20
In the case of the present embodiment, the inner peripheral portion 7b of the edge 7 is bonded to
the outer peripheral side of the second diaphragm 6 from the back side and connected. However,
the edge 7 b may be bonded so as to overlap the front surface side of the outer diameter end of
the first diaphragm 5, and in this case as well, the engagement flange portion 5 b of the first
diaphragm 5 can support and move It may be engaged with the annular recess 7d of the portion
7c. It is possible to bond the voice coil bobbin 2 and the second diaphragm 6 without tilting the
first diaphragm 5, and to realize a speaker vibration system of a double diaphragm structure
having sufficient rigidity.
[0054]
In addition, although the speaker 1 of the present embodiment is an electrodynamic speaker
including the bullet-shaped equalizer 9 and not including the dust cap covering the upper end
side of the cylindrical voice coil bobbin 2, the present invention is limited to such an
embodiment. It is not a thing. When the bullet-shaped equalizer 9 is not provided, a dust cap
connected to the voice coil bobbin 2 or the first diaphragm 5 may be provided.
[0055]
FIG. 6 is an enlarged view of the main part illustrating the speaker vibration system of the
speaker 21 (not shown) according to another preferred embodiment, and in the same manner as
in FIG. 2 of the previous embodiment, the X part shown in FIG. It is sectional drawing to which
the part corresponded to was expanded. The speaker 21 is a common speaker except that the
configuration of the first diaphragm 5 constituting the double diaphragm structure is different
from that of the speaker 1 of the previous embodiment. Therefore, the description of the
configurations of the voice coil bobbin 2, the second diaphragm 6, and the edge 7 which are
common to each other will be omitted.
[0056]
Like the first diaphragm 5 of the previous embodiment, the first diaphragm 5 of the present
embodiment is thermosetting on a base material that is a laminate including a woven fabric layer
or a non-woven fabric layer made of inorganic fibers or natural fibers. It includes a base (a
diaphragm portion 5a, an engagement ridge portion 5b, a ridge portion 5c, and an engagement
recess 5d) which is formed by being impregnated with a resin. The diaphragm is different in that
10-05-2019
21
it does not have the surface material 5e adhered to the front side of the base in the case of the
previous embodiment, and the base is exposed on the front side. Specifically, the substrate is
obtained by laminating a non-woven fabric of Technora fiber and a non-woven fabric of cotton,
impregnating the unsaturated polyester resin, and hot pressing. The inner diameter end of the
first diaphragm 5 is connected to the outer curved surface of the voice coil bobbin 2 by an
acrylic adhesive.
[0057]
As a result, the first diaphragm 5 of the present embodiment has the following physical
properties, and the frequency f1 of the mode in which the outer peripheral side of the single first
diaphragm 5 is divided and vibrated is set to about 3.0 kHz. The first diaphragm 5 of the present
embodiment does not have the surface material 5e, and therefore does not exhibit remarkable
anisotropy such that the Young's modulus changes largely depending on the background.
However, since the first diaphragm 5 of this embodiment can be reduced in weight by the
amount not including the surface material 5 e, the reproduction efficiency of the speaker 21 can
be enhanced. (Example 2) First diaphragm 5 thickness t1 0.22 mm weight 3.1 g basis weight 349
g / m <2> Young's modulus E1 6.5 E + 9 Pa internal loss tan δ1 0.07 density (specific gravity)
11 1.3 g / cm < 3>
[0058]
Further, the second diaphragm 6 of the present embodiment is the same as the previous
embodiment, and as a result, the Young's modulus E2 of the second diaphragm 6 is compared
with the Young's modulus E1 of the first diaphragm 5. The internal loss δ2 of the second
diaphragm 6 is larger than the internal loss δ1 of the first diaphragm 5, and the specific gravity
22 of the second diaphragm 6 is greater than the specific gravity 11 of the first diaphragm 5
Meet the set relationship.
[0059]
Further, the speaker vibration system of the double diaphragm structure of the speaker 21 of the
present embodiment is a second diaphragm 6 defined as a portion to which the inner peripheral
portion 7b of the edge 7 is connected as in the case of the previous embodiment. The outer
peripheral edge portion of the second diaphragm 6 forms a separation space Y between the first
diaphragm 5 and the distance from the engaging portion 6b of the second diaphragm 6 toward
the inner circumferential side.
10-05-2019
22
Therefore, by providing this separated space Y, the outer periphery of the first diaphragm 5 that
emits sound waves on the front side can be divided and vibrated more than the first diaphragm 5,
and the outer periphery of the second diaphragm 6 is even stronger. A structure is realized in
which the side reinforces.
[0060]
In the double diaphragm structure of the speaker 21 of the present embodiment, the frequency
fh of the first mode in which the outer peripheral side starts divided vibration is about 4.0 kHz,
and at frequencies below that, the first diaphragm 5 and the second vibration The plate 6 is
vibrating in a piston. In the speaker vibration system of the double diaphragm structure forming
the separation space Y of the speaker 1 of the present embodiment, the frequency f1 of the
lowest mode in which the outer peripheral side of the first diaphragm 5 starts divided vibration,
and the outer peripheral side divided vibration. The second diaphragm 6 having a higher mode
frequency f2 to be started can push up to a higher frequency to expand the piston vibration area
more than in the past.
[0061]
As shown in FIG. 6, separately from the first adhesive Ad1, which is a rubber-based adhesive
applied to the engaging recess 5d of the first diaphragm 5 and the engaging portion 6b of the
second diaphragm 6, as shown in FIG. The different second adhesive Ad 2 may not necessarily be
applied to the separation space Y defined between the first diaphragm 5 and the second
diaphragm 6. Of course, the second adhesive Ad2 is the same acrylic resin emulsion adhesive as
in the previous embodiment, and the adhesive has a relatively small Young's modulus after
curing and is soft and has a large internal loss, It may be separately applied so as not to mix with
the first adhesive Ad1.
[0062]
FIG. 7 is an enlarged view of the main part illustrating the speaker vibration system of the
speaker 22 (not shown) according to another preferred embodiment, and in the same manner as
in FIG. 2 of the previous embodiment, the X part shown in FIG. It is sectional drawing to which
10-05-2019
23
the part corresponded to was expanded. The speaker 22 is a common speaker except that the
configuration of the first diaphragm 25 constituting the double diaphragm structure is different
from that of the previous embodiment, as compared with the speaker 1 or 21 of the previous
embodiment. . Therefore, the description of the configurations of the voice coil bobbin 2, the
second diaphragm 6, and the edge 7 which are common to each other will be omitted.
[0063]
The first diaphragm 25 of the present embodiment differs from the first diaphragm 5 of the
previous embodiment in that a base (a diaphragm portion 25a, an engaging lever, and the like) is
made of a paper material formed by making paper fibers. It includes a portion 25b, a ridge
portion 25c, and an engagement recess 25d. And a surface material 25e adhered to the front side
of the substrate and exposed to the front side. The base of the first diaphragm 25 is a paper cone
formed by papermaking, press-dried, cut and shaped, and a substantially cone-shaped diaphragm
having substantially the same dimensions as in the previous embodiment except for the paper
material. A point including a portion 25a, an engagement ridge portion 25b extended so as to be
folded back from the outer peripheral end thereof, a ridge line portion 25c convex on the front
side, and an engagement recess 25d on the back side of the ridge line 25c Match on. Since the
paper material is lightweight, inexpensive and inexpensive, the first diaphragm 25 can be
realized at low cost.
[0064]
Further, as the surface material 25 e of the present embodiment, a woven fabric of polyethylene
naphthalate fibers different from the case of the surface material 5 e provided in the first
diaphragm 5 of the first embodiment is used. The twill weave of polyethylene naphthalate fibers
forming the surface material 25e is one in which the composition ratio of warps and wefts of 40
yarns of 270 d / cm and yarns of 270 d / 31 / cm is 1.29. / 2 twill weave. The surface material
25e is obtained by applying a thermoplastic adhesive to this substrate and drying it, and then
woven a twill woven polyethylene fiber along with a hot melt film, and heat pressing these to
form the first diaphragm 25. Integrate as. The inner diameter end of the first diaphragm 25 is
connected to the outer curved surface of the voice coil bobbin 2 by an acrylic adhesive as in the
case of the previous embodiment.
[0065]
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24
As a result, the first diaphragm 25 of the present embodiment has the following physical
properties, and the frequency f1 of the mode in which the outer peripheral side of the single first
diaphragm 25 is divided and vibrated is set to about 2.8 Hz. (Example 3): 1st diaphragm 25
thickness t1 0.28 mm weight 3.0 g basis weight 338 g / m <2> Young's modulus E11
(longitudinal direction) 3.5E + 9 Pa Young's modulus E12 (latitude direction) 3.1E + 9 Pa internal
loss tan δ1 0.15 density (specific gravity) 11 1.0 g / cm <3>
[0066]
Further, the second diaphragm 6 of this embodiment is the same as that of the previous
embodiment, and as a result, the Young's modulus E2 of the second diaphragm 6 corresponds to
the Young's modulus E11 to E12 of the first diaphragm 25. In comparison, the internal loss δ2
of the second diaphragm 6 is larger than the internal loss δ1 of the first diaphragm 25, and the
specific gravity 22 of the second diaphragm 6 is the same as the specific gravity 11 of the first
diaphragm 25. Satisfy the relationship set smaller compared.
[0067]
Further, the speaker vibration system of the double diaphragm structure of the speaker 22 of the
present embodiment is a second diaphragm 6 defined as a portion to which the inner peripheral
portion 7b of the edge 7 is connected as in the case of the previous embodiment. The outer
peripheral edge portion of the second diaphragm 25 forms a separation space Y between the
first diaphragm 25 and the distance from the engaging portion 6b of the second diaphragm 6
toward the inner circumferential side.
Therefore, by providing this separation space Y, the outer periphery of the first diaphragm 25
that emits sound waves on the front side can be divided and vibrated more than the first
diaphragm 25, and the outer periphery of the second diaphragm 6 is even stronger. A structure
is realized in which the side reinforces.
[0068]
In the double diaphragm structure of the speaker 22 of the present embodiment, the frequency
fh of the first mode in which the outer peripheral side starts divided vibration is about 4.0 kHz,
and at frequencies lower than that, the first diaphragm 5 and the second vibration The plate 6 is
10-05-2019
25
vibrating in a piston. The speaker vibration system of the double diaphragm structure forming
the separation space Y of the speaker 22 of the present embodiment has a frequency f1 of the
mode in which the outer peripheral side of the first diaphragm 25 starts divided vibration, and
the outer peripheral side is higher in which divided vibration starts. The second vibration plate 6
having the mode frequency f2 can be pushed up to a higher frequency to expand the piston
vibration region more than in the prior art.
[0069]
The surface material 25e of the first diaphragm 25 of the present embodiment is a woven fabric
of twill weave of polyethylene naphthalate fiber, and the woven fabric having anisotropy is a
warp and weft of the woven fabric. Since the size of the composition ratio is about 1.2 or more,
the change in Young's modulus according to the longitudinal direction becomes large. In the first
diaphragm 25 including the surface material 25e, the resonance frequency in the high region is
dispersed, the sound pressure frequency characteristic is likely to be flat, and the high region is
not severe in terms of hearing, and it becomes very easy to hear.
[0070]
The first adhesive Ad1 applied to the engagement recess 25d of the first diaphragm 25 and the
engagement portion 6b of the second diaphragm 6 engaged here is the same rubber-based
adhesive as in the previous embodiment. It is an adhesive which has a relatively large Young's
modulus after curing of the adhesive, is hard and has a small internal loss. In addition, the second
adhesive Ad2 different from the first adhesive Ad1 and applied and filled in the separation space
Y defined between the first diaphragm 25 and the second diaphragm 6 is the embodiment
described above. The same acrylic resin emulsion adhesive as in the case of (1) may be used as
long as it has a relatively small Young's modulus after curing and is soft and has a large internal
loss. For example, in the case of using an epoxy-based adhesive, which is relatively hard and is
harder than the rubber-based adhesive but not the rubber-based adhesive, or the acrylic
adhesive, the second adhesive Ad2 is used as the first adhesive Ad1. Rubber adhesive may be
used. The first adhesive Ad1 and the second adhesive Ad2 are preferably separately applied so as
not to be mixed.
[0071]
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26
FIG. 8 is an enlarged view of the main part illustrating the speaker vibration system of the
speaker 23 (not shown) according to another preferred embodiment, and in the same manner as
FIG. 2 of the previous embodiment, the X part shown in FIG. It is sectional drawing to which the
part corresponded to was expanded. The speaker 23 is a speaker common to the speaker 1 of the
previous embodiment except that the configuration of the first diaphragm 5 constituting the
double diaphragm structure is different from that of the first embodiment. Therefore, the
description of the configurations of the voice coil bobbin 2, the second diaphragm 6, and the
edge 7 which are common to each other will be omitted.
[0072]
Like the first diaphragm 25 of the third embodiment, the first diaphragm 25 of the present
embodiment is a base (a diaphragm portion 25 a, engagement) using a paper material formed by
forming paper fibers as a substrate. It includes a ridge portion 25b, a ridge line portion 25c, and
an engagement recess 25d. And the diaphragm which is exposed to the front side, and differs
from the diaphragm 3 in that it does not have the surface material 25e adhered to the front side
of the base in the case of the third embodiment. Specifically, as described above, the base of the
first diaphragm 25 is a paper cone which is made by paper making, press drying, and cut and
formed. The inner diameter end of the first diaphragm 25 is connected to the outer curved
surface of the voice coil bobbin 2 with an acrylic adhesive.
[0073]
Even if the first diaphragm 25 of the present embodiment is a paper cone having a paper
material as a base, it has the following physical properties, and the frequency f1 of the mode in
which the outer peripheral side of the single first diaphragm 25 divides and vibrates is , Is set to
about 2.5kHz. The first diaphragm 25 of the present embodiment does not have the surface
material 25 e, and therefore does not exhibit remarkable anisotropy such that the Young's
modulus changes largely depending on the background. However, since the first diaphragm 25
of the present embodiment can be reduced in weight by the amount not provided with the
surface material 25 e, the reproduction efficiency of the speaker 21 can be enhanced. (Example
4): First diaphragm 25 thickness t1 0.35 mm Weight 2.5 g Basis weight 281 g / m <2> Young's
modulus E 2.6 E + 9 Pa Internal loss tan δ1 0.13 Density (specific gravity) 11 0.80 g / cm < 3>
[0074]
The second diaphragm 6 of this embodiment is the same as that of the previous embodiment,
10-05-2019
27
and as a result, the Young's modulus E2 of the second diaphragm 6 is smaller than the Young's
modulus E1 of the first diaphragm 25. The internal loss δ2 of the second diaphragm 6 is larger
than the internal loss δ1 of the first diaphragm 25, and the specific gravity 22 of the second
diaphragm 6 is smaller than the specific gravity 11 of the first diaphragm 25. Meet the set
relationships.
[0075]
In addition, the speaker vibration system of the double diaphragm structure of the speaker 23 of
the present embodiment is a second diaphragm 6 defined as a portion to which the inner
peripheral portion 7b of the edge 7 is connected as in the case of the previous embodiment. The
outer peripheral edge portion of the second diaphragm 25 forms a separation space Y between
the first diaphragm 25 and the distance from the engaging portion 6b of the second diaphragm 6
toward the inner circumferential side.
Therefore, by providing this separation space Y, the outer periphery of the first diaphragm 25
that emits sound waves on the front side can be divided and vibrated more than the first
diaphragm 25, and the outer periphery of the second diaphragm 6 is even stronger. A structure
is realized in which the side reinforces.
[0076]
In the double diaphragm structure of the speaker 23 of the present embodiment, the frequency
fh of the first mode in which the outer peripheral side starts divided vibration is about 3.5 kHz,
and at frequencies lower than that, the first diaphragm 25 and the second vibration The plate 6
is vibrating in a piston. The speaker vibration system of the double diaphragm structure forming
the separation space Y of the speaker 1 of the present embodiment has a frequency f1 of the
mode in which the outer peripheral side of the first diaphragm 25 starts divided vibration, and
the outer peripheral side is higher The second diaphragm 6 having the lowest order mode
frequency f2 can be pushed up to a higher frequency to expand the piston vibration region more
than in the prior art.
[0077]
10-05-2019
28
FIG. 9 is a schematic cross-sectional view of a speaker 31 according to another preferred
embodiment of the present invention. The speaker 31 does not have the bullet-shaped equalizer
9 in comparison with the speaker 1 of the previous embodiment, and the other constitution is
different from that of the previous embodiment in the configuration of the first diaphragm
constituting the double diaphragm structure. Is an almost common speaker. Specifically, the
speaker 31 is different in that it has the first diaphragm 35 formed by integrating the inverted
dome-shaped central portion 33 integrally with the diaphragm portion 35a, and does not include
the cannonball-like equalizer 9, It is common in the point provided with the 2nd diaphragm 6
common to an example, etc. Therefore, the description of the common configuration is omitted.
[0078]
Like the first diaphragm 25 of the previous embodiment, the first diaphragm 35 constituting the
speaker 31 is a base (a diaphragm part, an engagement lever, and the like) having a paper
material formed by forming paper fibers as a substrate Part, ridge line part, engagement recess.
Is a diaphragm exposed to the front side, and is a diaphragm not provided with the surface
material 25e bonded to the front side of the base. Specifically, the base of the first diaphragm 35
is a paper cone which is made by making paper, pressing and drying, cutting the outer peripheral
side leaving the central portion 33. The first diaphragm 35 has a connecting portion 32
connected to the end of the voice coil bobbin 2 on the inner peripheral side of the substantially
cone-shaped base, and an inverted dome-shaped central portion 33 covering the inner peripheral
side of the connecting portion 32. And are formed integrally with the substrate. The connecting
portion 32 is defined by a step that is formed in an annular shape, or a rib whose thickness
changes in part. The end of the voice coil bobbin 2 is connected to the connecting portion 32 of
the first diaphragm 35 with an acrylic adhesive.
[0079]
Even if the first diaphragm 35 of the present embodiment is a paper cone using a paper material
as a base material, the first diaphragm 35 has the following physical properties, and in the lowest
order mode in which the outer peripheral side of the single first diaphragm 35 divides and
vibrates. The frequency f1 is set to about 2.8 kHz. The first diaphragm 35 of this embodiment
does not have a surface material, and therefore does not exhibit remarkable anisotropy such that
the Young's modulus changes largely depending on the background. However, since the first
diaphragm 35 of the present embodiment can be reduced in weight by the amount without the
surface material, the reproduction efficiency of the speaker 31 can be enhanced. (Example 5):
First diaphragm 35 thickness t1 0.35 mm weight 2.5 g basis weight 281 g / m <2> Young's
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modulus E1 2.6 E + 9 Pa internal loss tan δ1 0.13 density (specific gravity) 11 0.8 g / cm < 3>
[0080]
In addition, the speaker vibration system of the double diaphragm structure of the speaker 31 of
the present embodiment is the second diaphragm 6 defined as a portion to which the inner
peripheral portion 7b of the edge 7 is connected as in the case of the previous embodiment. The
outer peripheral edge portion of the second diaphragm 35 forms a separation space Y between
the first diaphragm 35 and the distance from the engaging portion 6b of the second diaphragm 6
toward the inner circumferential side. Therefore, by providing this separation space Y, the outer
periphery of the first diaphragm 35 that radiates sound waves on the front side can be divided
and vibrated more than the first diaphragm 35, and the outer periphery of the second diaphragm
6 is stronger. A structure is realized in which the side reinforces.
[0081]
The first diaphragm 35 of the present embodiment has its central portion 33 to increase its
rigidity, so a more robust double diaphragm structure is realized, and the frequency of the mode
in which the outer peripheral side starts divided vibration is made higher The piston vibration
area can be expanded. Further, since the first diaphragm 35 is provided with the connecting
portion 32 connected to the end of the voice coil bobbin 2, the voice coil bobbin 2 is closely
connected to the first diaphragm 35 and has a double diaphragm structure with high rigidity.
The vibration system of the speaker is configured. Therefore, it is possible to realize the speaker
31 excellent in the reproduction sound quality with less peak dip on the sound pressure
frequency characteristic.
[0082]
FIG. 10 is a schematic cross-sectional view of a speaker 41 according to another preferred
embodiment of the present invention. The speaker 41 is substantially the same as the speaker 31
of the previous embodiment except that the configuration of the first diaphragm 45 constituting
the double diaphragm structure is different from that of the first embodiment. . Specifically, the
speaker 41 is different in that it includes a first diaphragm 45 formed by integrating the domeshaped central portion 43 with the diaphragm portion, and includes the second diaphragm 6
common to the previous embodiment. It is common in points. Therefore, the description of the
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common configuration is omitted.
[0083]
Similarly to the first diaphragm 5 of the previous embodiment, the first diaphragm 45
constituting the speaker 41 is thermally cured on a base material that is a laminate including a
woven fabric layer or a non-woven fabric layer made of inorganic fibers or natural fibers. It is a
diaphragm which is provided with a base formed by impregnating a base resin and a surface
material 44 adhered to the front side of the base, and the surface material 44 is exposed on the
front side. Specifically, the substrate is obtained by laminating Technola fiber non-woven fabric
and cotton non-woven fabric, impregnating with unsaturated polyester resin and heat-press
forming, and the surface material 44 is a thermoplastic adhesive on this substrate And a woven
fabric of silk fibers of satin weave is placed along with the hot melt film, and these are integrated
by heat pressing. The woven fabric of satin-woven silk fiber forming the surface material 44 is
composed of silk raw yarn with 21 / 2d 130 yarns / cm and weft 21 / 3d 49 yarns / cm with a
composition ratio of 1.77 It was made with 3 pieces and 5 pieces of satin weave.
[0084]
The first diaphragm 45 of this embodiment has the following physical properties, and the
frequency f1 of the mode in which the outer peripheral side of the single first diaphragm 45 is
divided and vibrated is set to about 3.5 Hz. Since the first diaphragm 45 of the present
embodiment includes the surface material 44 made of satin-woven silk fiber, the first diaphragm
45 exhibits anisotropy in which Young's modulus largely changes depending on the background.
In the first diaphragm 45 including the surface material 44, the resonance frequency in the high
region is dispersed, the sound pressure frequency characteristic is likely to be flat, and the high
frequency is not severe in terms of auditory sense, and it becomes very easy to hear. (Example 6):
1st diaphragm 45 thickness t1 0.3 mm weight 3.9 g weight 439 g / m <2> Young's modulus E11
(longitudinal direction) 3.5E + 9Pa Young's modulus E12 (latitude direction) 3.1E + 9Pa internal
loss tan δ1 0.1 Density (specific gravity) 11 1.2 g / cm <3>
[0085]
Therefore, the speaker vibration system of the double diaphragm structure of the speaker 41 of
the present embodiment is the second diaphragm 6 defined as a portion to which the inner
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31
peripheral portion 7b of the edge 7 is connected as in the case of the previous embodiment. The
outer peripheral edge portion of the second diaphragm 45 forms a separation space Y between
the first diaphragm 45 and the distance from the engaging portion 6b of the second diaphragm 6
toward the inner circumferential side. Therefore, by providing this separation space Y, the outer
periphery of the first diaphragm 45 that emits sound waves on the front side can be divided and
vibrated more than the first diaphragm 45, and the outer periphery of the second diaphragm 6 is
stronger. A structure is realized in which the side reinforces.
[0086]
In addition, the first diaphragm 45 has a connecting portion 42 connected to the end of the voice
coil bobbin 2 on the inner peripheral side of the substantially cone-shaped base, and a domeshaped central portion 43 covering the inner peripheral side of the connecting portion 42. And
are formed integrally with the substrate. The connection portion 42 is defined by a plurality of
circularly spaced conical projections. The conical protrusion is a substantially conical protrusion
formed by curing a thermosetting resin so as to protrude from the back side of the diaphragm
portion 45 a of the first diaphragm 45. That is, the conical projections are preferably molded of
unsaturated polyester without a substrate. As the curing speed is high and the curing
temperature is low, the connection 42 is obtained which is easy to manufacture and has excellent
internal loss. Since the connecting portion 42 is impregnated with the thermosetting resin on the
base of the diaphragm portion 45a, the thermosetting resin is dropped onto the shape portion of
the connecting portion 42 of the mold and cured, so that the manufacturing is extremely
important. Be simplified.
[0087]
The first diaphragm 45 of the present embodiment has the central portion 43 to increase the
rigidity of the first diaphragm, so a more robust double diaphragm structure is realized, and the
frequency of the mode in which the outer peripheral side starts divided vibration Can be pushed
to a higher frequency to expand the piston vibration area. Further, since the first diaphragm 45
includes the connecting portion 42 connected to the end of the voice coil bobbin 2, the double
diaphragm having high rigidity so that the voice coil bobbin 2 is closely connected to the first
diaphragm 45. The vibration system of the speaker of structure is constituted. Therefore, it is
possible to realize the speaker 41 excellent in reproduced sound quality with less peak dip on the
sound pressure frequency characteristic.
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[0088]
Although the preferred embodiments of the present invention have been described, the present
invention is not limited to these embodiments. In the speaker of the present invention provided
with a first diaphragm formed by impregnating a substrate with a thermosetting resin, the
connecting portion 42 of the first diaphragm 45 is formed by curing of the thermosetting resin,
for example. And a plurality of conical projections which project to the back side and are
annularly spaced apart, and the plurality of conical projections define a connecting portion 42 to
which one end of the voice coil bobbin 2 is connected. If so, the size and arrangement of the
conical projections do not matter.
[0089]
The vibration system of the speaker of the present invention can be suitably applied to a speaker
used for various applications (home use, car use). Furthermore, it can be applied to any speaker,
such as a woofer that reproduces particularly in the low frequency region, or a full range speaker
that reproduces also in the high frequency region. Further, the vibration system of the present
invention can be applied not only to the speaker but also to the microphone.
[0090]
1, 21, 22, 23, 31, 41, 100 Speaker 2 voice coil bobbin 3 voice coil 4 damper 5, 25, 35, 45, 50
first diaphragm 5 a, 25 a diaphragm portion 5 b, 25 b engagement collar 5 c, 25c ridge portion
5d, 25d engaging recess 5e, 25e, 44 surface material 6, 60 second diaphragm 6a, 60a
diaphragm portion 6b, 60b engaging portion 7, 70 edge 7a, 70a outer peripheral portion 7b, 70b
inner peripheral portion 7c, 70c support movable part 7d, 70d annular recess 8 frame 9
equalizer 10 magnetic circuit
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