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DESCRIPTION JP2008167137

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DESCRIPTION JP2008167137
An object of the present invention is to provide a speaker capable of suppressing the generation
of noises even when the outer surface is provided with a center cap formed by a complicated
curved surface. A speaker includes a magnetic circuit unit and a vibrating unit. The vibrating
portion includes a diaphragm and a center cap 16 which are vibrated by the magnetic circuit
portion. The cap main body 53 of the center cap 16 is provided with a convex central portion 55
in the acoustic radiation direction and a peripheral edge portion 56 connected to the outer edge
of the central portion 55 and formed in a convex shape opposite to the acoustic radiation
direction. The center cap 16 is formed with a concave cross section 63 from the central portion
55 to the outer edge. A center cap reinforcing plate 57 for improving the mechanical strength of
the center cap 16 is attached to the back surface 53 b of the center cap 16. [Selected figure]
Figure 2
スピーカ
[0001]
The present invention relates to, for example, a speaker that vibrates a diaphragm by supplying
an audio current to generate a sound.
[0002]
For example, various speakers are conventionally mounted on a vehicle as a moving body.
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The speaker includes a bottomed cylindrical frame, a vibrating portion housed in the frame, and
a magnetic circuit portion attached to the frame and generating a driving force in the vibrating
portion.
[0003]
The vibrating portion is housed in the frame. The vibration unit includes a voice coil to which an
audio current is supplied, a diaphragm attached to the voice coil, and a center cap (for example,
see Patent Document 1) attached to the acoustic radiation direction side of the diaphragm. . The
center cap is made of resin. The center cap is integrally formed with a cap main body formed in a
thin plate shape and having a central portion formed in a curved surface shape convex toward
the acoustic radiation direction, and a protrusion protruding from the back surface of the cap
main body. The driving force refers to an electromagnetic force (also referred to as Lorentz force)
generated when a voice current flows through the voice coil. Hereinafter, the surface on the
acoustic radiation side where the speaker emits sound is referred to as the outer surface, and the
surface opposite to the acoustic radiation side is referred to as the back surface.
[0004]
The magnetic circuit unit includes a permanent magnet, and a voice coil is disposed in the
magnetic gap.
[0005]
In the speaker having the above-described configuration, an electromagnetic current (Lorentz
force) acts on the voice coil by supplying a voice current to the voice coil, thereby vibrating the
diaphragm and responding to the above-described voice current. Sound is generated in the
direction of acoustic radiation.
JP 2000-270396 A
[0006]
The center cap of the speaker shown in Patent Document 1 described above is formed in a
simple shape in which the cap body is curved in a convex direction toward the sound radiation
direction, and the protrusion is integrally formed on the outer surface. There is a problem that
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dents called sinks occur.
[0007]
In addition, the dent on the outer surface of the center cap impairs the aesthetic appearance and
is undesirable, and there is a problem that a crack or the like is generated on the outer surface.
Further, as described above, the center cap whose outer surface is formed by a simple curved
surface has a problem of generating noise when the diaphragm is vibrated.
[0008]
In addition, when the diaphragm is vibrated with a large amplitude, a large phase difference
occurs between the sound wave generated from the center and the sound wave generated from
the outer periphery particularly in the shape of the center cap as described above, and the
acoustic characteristics are degraded. There is a problem of causing
[0009]
The present invention takes as an example the problem to address such problems.
An object of the present invention is, for example, to provide a speaker capable of suppressing
the generation of noises even when the center cap is provided with a complex curved outer
surface, and the strength of the center cap is increased. To provide a reliable speaker capable of
reproducing sound over a long period of time.
[0010]
In order to solve the above problems and achieve the object, the speaker of the present invention
according to claim 1 comprises a frame, a magnetic circuit unit supported by the frame, and a
vibrating unit supported by the frame, The vibration unit includes a voice coil to which an audio
current is supplied, a vibrating plate vibrating by a driving force acting on the voice coil, and a
center cap attached to the vibrating plate, and a central portion of the center cap is acoustic. A
convex shape is formed in a radial direction, and a concave cross section from the central portion
to the outer edge portion of the center cap is formed, and the outer surface of the center cap is
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formed in a gentle curved surface, the center A center cap reinforcing plate is attached to the
back of the cap.
[0011]
Hereinafter, an embodiment of the present invention will be described.
The speaker according to one embodiment of the present invention improves the mechanical
strength and rigidity of the center cap by attaching a center cap reinforcing plate to the back
surface of the center cap, and the center cap vibrates together with the diaphragm. Restraint. By
doing this, the projecting portion is integrally provided on the back surface side of the center cap
to cause sinks and the like on the outer surface, and the appearance is not impaired. Also, the
mechanical strength of the center cap can be increased. Furthermore, it is possible to suppress
the generation of abnormal noise in the center cap when the diaphragm is vibrated.
[0012]
In addition, the outer surface of the center cap of this embodiment has a convex central portion
and a concave cross-sectional portion extending from the central portion to the outer edge
portion, as compared with a simple shape in which the central portion is convexly formed in the
acoustic radiation direction Is formed and formed into a gentle curved surface, so that it has a
nearly flat shape. Therefore, the phase difference between the sound wave generated from the
center of the center cap and the sound wave generated from the outer edge can be reduced.
Therefore, it is possible to suppress the generation of abnormal sound that is seen as sharp peaks
and valleys (referred to as peak dip) in the sound pressure frequency characteristics, particularly
on the central axis of the speaker.
[0013]
In the speaker according to the other embodiment, by forming a rib on the back surface of the
center cap, mechanical strength and rigidity of the center cap are improved, and the center cap is
prevented from vibrating with the diaphragm. ing. By doing this, the mechanical strength of the
center cap can be increased. Furthermore, while the center cap can suppress generation of
abnormal noise when the diaphragm vibrates, peaks and valleys (peaks and peaks) are generated
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in the sound pressure frequency characteristics particularly on the central axis of the speaker, as
in the embodiment described above. It is possible to suppress the generation of abnormal sound,
which is seen as dip).
[0014]
The center cap reinforcing plate may include the reinforcing plate main body and the projecting
portion. In this case, the mechanical strength and rigidity of the center cap reinforcing plate itself
can be reliably improved, so that the mechanical strength of the center cap can be reliably
improved, and the center cap can generate noise when the diaphragm is vibrated. It can be
prevented reliably.
[0015]
Furthermore, the central portion of the center cap may further form a convex cross-sectional
portion to the outer edge portion. In this case, the outer surface of the center cap has a shape
more flatter than the simple shape in which the central portion is convexly formed in the acoustic
radiation direction, and particularly the sound pressure frequency on the central axis of the
speaker It is possible to reliably suppress the generation of abnormal noise, which is seen as
sharp peaks and valleys (referred to as peak dip) in characteristics.
[0016]
Further, a drive cone for transmitting the vibration of the voice coil may be provided on the
diaphragm to provide a sealed space between the diaphragm, the frame, and the drive cone. In
this case, since the gas in the space attenuates the vibration of the diaphragm, it is not necessary
to provide a damper used for the conventional speaker. Therefore, the configuration of the
speaker can be simplified. Furthermore, since the strength of the center cap can be increased to
prevent the center cap from vibrating together with the diaphragm, a highly reliable speaker
capable of reproducing sound over a long period of time can be provided.
[0017]
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One embodiment of the present invention will be described with reference to FIGS. A speaker 1
according to an embodiment of the present invention shown in FIG. 1 is mounted on an
automobile or the like as a moving body to provide voice information to the occupants of the
automobile.
[0018]
As shown in FIG. 1, the speaker 1 includes a frame 4, a magnetic circuit unit 2, a vibrating unit 3,
and a wiring structure unit 5.
[0019]
As shown in FIG. 1, the frame 4 includes a frame body 20, a connector frame (not shown), and a
gasket 23.
[0020]
The frame body 20 is made of metal such as aluminum.
The frame main body 20 protrudes from an annular bottom portion 24, a cylindrical cylindrical
portion 25 formed to rise from the outer peripheral edge of the bottom portion, and an inner
surface (also referred to as an inner side surface or an inner peripheral surface) of the cylindrical
portion 25 And a flange portion 26.
[0021]
The flange portion 26 is formed in an annular shape and protrudes from the inner surface of the
cylindrical portion 25 toward the inside of the cylindrical portion 25.
The flange portion 26 is provided along the inner surface of the cylindrical portion 25 over the
entire circumference of the cylindrical portion 25. Further, the flange portion 26 is provided with
one hole into which a tube member (not shown) to be described later is press-fit. This hole, of
course, passes through the frame body 20 of the frame 4, i.e. the flange portion 26.
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[0022]
The connector frame is attached to the frame body 20. The connector frame is attached with a
connector that can be connected to the above-described amplifier mounted on a car or the like.
The connector may be a connector not only connectable to the amplifier but also connectable to
another electronic device.
[0023]
The gasket 23 is formed in an annular shape. The gasket 23 is superimposed on the outer edge
portion (outer periphery) of the frame main body 20, and is fixed to the frame main body 20 by
an adhesive or the like with an edge 18 described later between the outer edge portion. The
gasket 23 fixes the diaphragm 15 described later to the frame body 20 with the edge 18
interposed between the gasket 23 and the outer edge of the frame body 20.
[0024]
Further, the magnetic circuit unit cover 22 is attached to the frame 4 via the magnetic circuit unit
2. The magnetic circuit unit cover 22 includes an annular bottom portion 30 and a cylindrical
portion 31 formed to rise from the outer peripheral edge of the bottom portion 30. The magnetic
circuit unit cover 22 is fixed to a yoke 7 of the magnetic circuit unit 2 described later by bolts 32.
The plate 9 is fixed to the frame body 20 by bolts 33. The magnetic circuit unit cover 22 is fixed
to the frame main body 20 via the yoke 7 and the plate 9 described above, and is coaxial with the
frame main body 20. The term "coaxial" as used herein means that the central axes of the
magnetic circuit unit cover 22 and the frame main body 20 are substantially the same.
[0025]
The magnetic circuit unit 2 is fixed to both the magnetic circuit unit cover 22 and the frame main
body 20 described above, and is attached (supported) to the frame 4. As shown in FIG. 1, the
magnetic circuit unit 2 includes a yoke 7 made of a magnetic body (so-called paramagnetic body
or ferromagnetic body) or the like, a magnet 8 and a magnetic body (so-called paramagnetic
body or ferromagnetism) And a plate 9 made of body or the like. The yoke 7 is an external
magnetic magnetic circuit integrally including an annular bottom plate 10 and a cylindrical
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center pole 11 formed to rise from the inner edge of the bottom plate 10. In this embodiment, an
external magnet type magnetic circuit is disclosed. However, the present invention relates to an
internal magnet type magnetic circuit or a magnetic circuit using both an internal magnet type
and an external magnet type (a magnet is disposed inside and outside a voice coil bobbin) Circuit)
may be applied. In the present embodiment, the center pole is formed with an opening that leads
to the outside of the speaker device, but in the present invention, the opening may not be formed.
[0026]
The magnet 8 is formed in an annular shape. The inner diameter of the magnet 8 is larger than
the outer diameter of the center pole 11. The magnet 8 is superimposed on the bottom plate 10
through the center pole 11 inside. The magnet 8 described above may be excited by a permanent
magnet or a DC power supply.
[0027]
The plate 9 is formed in an annular shape. The inner diameter of the plate 9 is larger than the
outer diameter of the center pole 11. The plate 9 is superimposed on the magnet 8 in a state
where it passes through the center pole 11 of the yoke 7 and the voice coil bobbin 13 described
later. The yoke 7, the magnet 8 and the plate 9 described above are coaxially arranged such that
their centers are substantially the same. For this reason, the inner peripheral surfaces of the
magnet 8 and the plate 9 are spaced from the outer peripheral surface of the center pole 11 of
the yoke 7.
[0028]
Further, the yoke 7 described above is fixed to the cover 22 for the magnetic circuit portion by
bolts 32 penetrating the annular bottom portion 30 and the bottom plate 10. Further, the plate 9
is fixed to the frame body 20 by screwing a bolt 33 so as to penetrate the bottom 24 of the frame
body 20. Thus, the magnetic circuit unit 2 is fixed to the frame 4 by fixing the plate 9 to the
frame main body 20 and fixing the bottom plate 10 to the magnetic circuit unit cover 22. Of
course, the yoke 7, the magnet 8 and the plate 9 are arranged coaxially with the frame 4.
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[0029]
With the configuration described above, the magnetic circuit unit 2 forms a magnetic gap G
having a large magnetic flux density between the outer peripheral surface of the center pole 11
of the yoke 7 and the inner peripheral surface of the plate 9.
[0030]
The vibrating portion 3 is housed (supported) in the frame main body 20 of the frame 4.
The vibration unit 3 includes a voice coil 12, a voice coil bobbin 13, a drive cone 14, a diaphragm
15, a center cap 16, and the like. Two voice coils 12 are provided in the present embodiment,
and two voice coils 12 are wound together around the outer periphery of the voice coil bobbin
13 (not shown). Further, these voice coils 12 are disposed in the above-described magnetic gap G
of the magnetic circuit unit 2 before driving the diaphragm 15. Voice current is supplied to the
voice coil 12.
[0031]
The voice coil bobbin 13 is formed in a cylindrical shape. The inner diameter of the voice coil
bobbin 13 is formed larger than the outer diameter of the center pole 11 of the yoke 7. The outer
diameter of the voice coil bobbin 13 is smaller than the inner diameter of the plate 9 and the
magnet 8. The voice coil bobbin 13 is disposed coaxially with the yoke 7, the plate 9, the voice
coil 12, and the like. One end of the voice coil bobbin 13 is inserted into the magnetic gap G, and
the voice coil 12 is attached to the outer periphery of the one end. The voice coil bobbin 13 is
movably supported along the central axis of the yoke 7 by the drive cone 14, the diaphragm 15,
and the like. The central axis of the yoke 7 is substantially the same as the central axis of the
speaker 1.
[0032]
The drive cone 14 transmits the vibration of the voice coil 12 to a diaphragm 15 described later.
The drive cone 14 is made of resin. The drive cone 14 is formed in an annular shape, and the
inner edge thereof is attached to the outer peripheral surface of the voice coil bobbin 13. An
elastically deformable edge 17 formed in an annular shape is attached to the outer edge of the
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drive cone 14 by an adhesive or the like. The bonding between the edge 17 and the drive cone
14 can be performed using a known means such as screwing or sewing in addition to the
adhesive. The outer edge portion of the edge 17 is sandwiched between the flange portion 26 of
the frame main body 20 and a positioning member 34 described later of the wiring structure
portion 5 and fixed thereto. That is, the drive cone 14 is attached to the frame body 20 or frame
4 via the edge 17.
[0033]
The diaphragm 15 is made of resin. The diaphragm 15 is formed in an annular shape. The
diaphragm 15 is fixed with a part of the drive cone 14 and, in particular, grooves indicated by
reference numerals 50, 51 and 52 in FIG. An edge 18 having a semicircular cross-sectional shape
is attached to the outer edge portion of the diaphragm 15 by an adhesive or the like. The outer
edge of the edge 18 is sandwiched between the outer edge of the cylindrical portion 25 of the
frame body 20 and the gasket 23 and fixed thereto. That is, the diaphragm 15 is attached to the
frame body 20 or the frame 4 through the edge 18.
[0034]
The center cap 16 is formed of a resin having large mechanical strength such as an ABS resin.
The center cap 16 is formed in a circular shape as shown in FIGS. 2 and 3. The outer diameter of
the center cap 16 is larger than the inner diameter of the diaphragm 15 and smaller than the
outer diameter of the diaphragm 15. The outer edge of the center cap 16 is bonded to the
diaphragm 15 using an adhesive or the like.
[0035]
As shown in FIGS. 2 and 3, the center cap 16 includes a cap main body 53 whose outer surface
53a is formed in a gentle curved surface, and a step 54 integrally formed with the cap main body
53. . The outer surface 53 a is the outer surface of the center cap 16. The cap body 53 integrally
includes a central portion 55 formed in a convex shape in the acoustic radiation direction, and a
plurality of (four in the illustrated example) peripheral portions 56 connected to the outer edge
of the central portion 55. The planar shape is formed in the shape of a shuriken (or flower). The
peripheral portions 56 are spaced apart from each other at equal intervals in the circumferential
direction, and are formed in a convex shape in the opposite direction of the acoustic radiation
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direction. For this purpose, the center cap 16 is formed between the central portion 55 and the
outer edge of the peripheral portion 56 over the entire circumference, as viewed in the acoustic
radiation direction, with a concave cross section 63 having a concave shape.
[0036]
As shown in FIG. 4, in the cap body 53, ie, the center cap 16, the central portion 55 described
above is convex toward the acoustic radiation direction, and the concave cross-sectional portion
63 is formed between the central portion 55 and the outer edge of the peripheral portion 56. Is
formed, and the outer surface 53a is formed in a gentle curved surface. That is, the center cap 16
is formed with a concave cross-sectional portion 63 from the central portion 55 to the outer edge
portion. No ridge line is formed on the outer surface 53a of the cap body 53 at all.
[0037]
The stepped portion 54 is provided between the peripheral edge portions 56 adjacent to each
other, and is formed in a flat plate shape. Further, the stepped portion 54 is disposed on the side
of the magnetic circuit portion 2 so as to be lower than the central portion 55 and the peripheral
portion 56 of the cap main body 53. The stepped portion 54 forms a step between the central
portion 55 and the peripheral portion 56 of the cap main body 53. The center cap 16 described
above is formed to have a constant thickness across the cap main body 53 and the step 54.
Further, at the central portion 55 of the cap main body 53 of the center cap 16, a protruding pin
61 is provided which protrudes in the direction opposite to the acoustic radiation direction.
[0038]
A center cap reinforcing plate 57 is attached to the back surface 53 b of the outer surface 53 a of
the cap body 53 of the center cap 16 described above. The center cap reinforcing plate 57 is
made of paper and formed in a thin plate shape. As shown in FIG. 5A, the planar shape of the
center cap reinforcing plate 57 is formed like a shuriken (flower) like the cap main body 53.
[0039]
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As shown in FIGS. 5 (a) and 5 (b), the center cap reinforcing plate 57 is reinforced so as to be
spaced apart from the reinforcing plate body 58 in close contact with the back surface 53b of the
cap body 53 and the back surface 53b of the cap body 53. A projection 59 projecting in the
direction opposite to the sound radiation direction from the plate body 58 is integrally provided.
At the center of the reinforcing plate body 58, a positioning hole 62 into which the projecting pin
61 penetrates is provided. The projection 59 is formed in an annular shape coaxial with the cap
body 53, ie, the center cap 16. In the center cap reinforcing plate 57 described above, the
reinforcing plate main body 58 is bonded to the cap main body 53, that is, the back surface 53 b
of the center cap 16 with an adhesive or the like to improve the mechanical strength of the
center cap 16.
[0040]
In the present embodiment, the center cap reinforcing plate 57 is made of paper, but in the
present invention, known materials such as polypropylene and acrylic resin can be used. Further,
in the present invention, the center cap reinforcing plate 57 may be formed by injection molding.
Further, in the present invention, in order to reduce the equivalent mass of the vibrating portion
3, the center cap reinforcing plate 57 may be formed of a foamed acrylic resin or the like.
[0041]
Of course, the drive cone 14, the diaphragm 15 and the center cap 16 of the vibration unit 3
described above are disposed coaxially with the frame 4 and the magnetic circuit unit 2. When
the current (sound current) according to the voice information is supplied to the voice coil 12,
the vibration unit 3 vibrates the diaphragm 15 to which the vibration of the voice coil 12 is
transmitted by the drive cone 14 along the central axis described above. And generate a sound
according to the audio current. That is, the diaphragm 15 vibrates by the driving force acting on
the voice coil 12.
[0042]
A space K surrounded by the drive cone 14, the diaphragm 15 and the edges 17 and 18
described above and the inner surface of the frame main body 20 of the frame 4 is sealed. That
is, the space K surrounded by the drive cone 14, the diaphragm 15 and the edges 17, 18 and the
inner surface of the frame main body 20 of the frame 4 is kept airtight.
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[0043]
For this reason, when the voice coil bobbin 13 vibrates along the central axis direction and the
drive cone 14 and the vibration plate 15 vibrate, the above-described vibration unit 3 generates a
space K between the drive cone 14 and the vibration plate 15. By repeating the compression and
expansion due to the displacement of the drive cone 14 and the diaphragm 15 and the
displacement of the edges 17 and 18, the air-bearing property of the present invention exhibits
the spring property as an air spring.
[0044]
In this embodiment, when the effective area of the diaphragm 15 is S1 and the effective area of
the drive cone 14 is S2, the difference S between the effective areas is S = S1-S2, and the drive
cone 14 and the diaphragm 15 Assuming that the volume V of air in the enclosed space K
between them, the stiffness which is a constant representing the spring property of the above air
spring is proportional to S / V.
That is, in the present embodiment, the air in the sealed space K between the drive cone 14 and
the diaphragm 15 is expressed, and the diaphragm 15 operates with a very large amplitude due
to the spring property as an air spring, etc. It is possible to suppress the abnormal behavior of
the speaker 1, to reproduce the acoustic characteristics of the speaker 1 for a long time, and to
maintain the reliability of the speaker 1 even if the diaphragm 15 is vibrated with a large
amplitude for a long time.
[0045]
In the speaker 1 having the above-described configuration, a voice current is supplied to the
voice coil 12 through a lead wire or the like (not shown), and the voice coil 12 disposed in the
magnetic gap G according to the voice current is along the central axis described above. To
vibrate. Then, the voice coil bobbin 13 in which the voice coil 12 is wound around the outer
periphery vibrates along with the drive cone 14 and the diaphragm 15 along the central axis.
That is, the vibration of the voice coil 12 is transmitted by the drive cone 14 and the diaphragm
15 vibrates to generate a sound according to the audio current.
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[0046]
According to the present embodiment, since the center cap reinforcing plate 57 is attached to the
back surface 53b of the cap body 53 of the center cap 16, a protrusion is integrally provided on
the back surface 53b side of the center cap 16 and hidden on the outer surface 53a. Etc., and the
mechanical strength of the center cap 16 can be improved. Therefore, the mechanical strength of
the center cap 16 can be improved, and the center cap 16 can be prevented from vibrating
together with the drive cone 14 and the diaphragm 15. Therefore, it is possible to prevent the
center cap 16 from generating noise when the diaphragm 15 vibrates.
[0047]
The center cap reinforcing plate 57 includes a reinforcing plate main body 58 and a projecting
portion 59. Therefore, since the rigidity of the center cap reinforcing plate 57 itself can be surely
increased, the mechanical strength or the rigidity of the center cap 16 can be surely increased.
When the diaphragm 15 vibrates, the center cap 16 generates noise. Can be reliably suppressed.
[0048]
The outer surface 53a of the center cap 16 has a nearly flat shape as compared to a simple shape
in which the central portion 55 is formed in a convex shape in the acoustic radiation direction.
Therefore, the phase difference between the sound wave generated from the central portion 55
of the center cap 16 and the sound wave generated from the outer edge portion can be reduced.
Therefore, especially on the central axis of the speaker 1, the generation of abnormal sound
caused by the disturbance of acoustic characteristics, which is seen as sharp peaks and valleys
(referred to as peak dip) in the sound pressure frequency characteristics, is suppressed. be able
to.
[0049]
The speaker 1 includes the drive cone 14 and the diaphragm 15, and by sealing the space K
between the frame 4 and the drive cone 14 and the diaphragm 15, it is not necessary to provide
a damper, and the configuration of the speaker 1 itself Can be simplified. Furthermore, since the
speaker 1 includes the above-described center cap reinforcing plate 57, the strength of the
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center cap 16 can be increased to prevent the center cap 16 from vibrating together with the
diaphragm 15. Therefore, the sound can be reproduced over a long period of time It can be made
highly reliable.
[0050]
Further, the speaker 1 has a spring property as an air spring expressed by air in a sealed space K
between the drive cone 14 and the diaphragm 15 as vibration energy of the voice coil bobbin 13,
the drive cone 14 and the diaphragm 15. In order to absorb the vibration of the voice coil bobbin
13 and to damp the vibration of the voice coil bobbin 13, it is not necessary to provide a damper
such as provided in a conventional speaker. That is, in the speaker 1 of the present embodiment,
the drive cone 14 and the diaphragm 15 themselves also serve as a damper for damping the
vibration of the drive cone 14, the diaphragm 15 and the voice coil bobbin 13. There is no need
to install a damper for supporting the voice coil bobbin 13 at the rear of the motor, and the axial
dimension can be shortened by omitting the damper and its installation space, and the thickness
reduction required for audio systems etc. mounted in automobiles etc. Can be realized.
[0051]
Moreover, the drive cone 14 coaxially mounted behind the diaphragm 15 to realize the space K
between the sealed drive cone 14 and the diaphragm 15 may be made of the same material as
the diaphragm 15, Since mechanical fatigue is less likely to occur as compared with the
conventional bellows-type damper, it is possible to prevent the deterioration of the reliability of
the speaker device due to the mechanical fatigue of the component parts, and to realize the
longer life of the speaker 1.
[0052]
Furthermore, a damper having a bellows structure (corrugation damper) is a voice coil to prevent
the roll (movement in the direction perpendicular to the central axis of the voice coil) of vibration
parts such as a voice coil, a voice coil bobbin and a diaphragm. It is deformed in a direction
perpendicular to the central axis of the coil, etc., to prevent the rolling, but there is no local
deformation of the drive cone 14 and the diaphragm 15, so rolling that causes muddy sound
quality It is possible to realize high quality sound reproduction without turbidity, without
generation of a unique vibration which is seen in the phenomenon or a rubbing sound which is
generated when the voice coil bobbin 13 contacts the plate 9 or the magnet 8 or the like.
[0053]
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15
And in the speaker 1 of this embodiment, when the diaphragm 15 is vibrating, the air in the
space K between the sealed drive cone 14 and the diaphragm 15 is repeatedly compressed and
expanded. Since the deformation due to the air pressure (back pressure) received on the back
side of the drive cone 14 and the edges 17 and 18 of the diaphragm 15 is less likely to occur, the
above-described unique vibration or rubbing noise is not generated. The drive cone 14 and the
diaphragm 15 can be vibrated with a large amplitude, and the sound can be reproduced at a
large volume.
Further, the drive cone 14 and the edge 17 can suppress abnormal behavior such as the
diaphragm 15 operating with a very large amplitude by an air spring expressed by air in the
space K, and the acoustic characteristics of the speaker 1 can be continued. It is possible to
reproduce the acoustic characteristics of the speaker 1 for a long time, and to maintain the
reliability of the speaker 1 even if the diaphragm 15 is vibrated with a large amplitude for a long
time.
[0054]
Next, the inventors of the present invention performed simulation using the speaker 1 of the
embodiment described above.
The simulation result is shown in FIG. The comparative example 1 shown by the alternate long
and short dash line in FIG. 6 shows the center cap 16 having a thickness of 1.0 mm without the
center cap reinforcing plate 57 attached in the above-described embodiment.
[0055]
The product 1 of the present invention shown by the solid line in FIG. 6 shows the center cap 16
with the thickness of 1.0 mm attached with the center cap reinforcing plate 57 shown in the
above-mentioned embodiment, and is shown by the solid line in FIG. The invention 2 shows the
center cap 16 having a thickness of 1.2 mm attached with the center cap reinforcing plate 57
shown in the above-described embodiment. The product 3 of the present invention shown by a
solid line in FIG. 6 has the center cap reinforcing plate 57 attached thereto in the abovedescribed embodiment (see the center cap 16 shown in FIG. 9 and the speaker 1 shown in FIG.
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16
Instead, the rib 64 is formed on the back surface 53b, and the center cap 16 having a thickness
of 1.2 mm is shown.
[0056]
In FIG. 6, the center cap 16 of the present invention products 1, 2, 3 and the comparative
example 1 described above is applied to the outer edge portion with a constant force equivalent
to 1 G (9.8 m / s <2>) at a predetermined frequency. The change in stress (N / m <2>) acting on
the bottom of the dent of the peripheral portion 56 described above was examined when it was
vibrated (vibration).
[0057]
According to FIG. 6, the stress acting on the bottom of the dent of the aforementioned peripheral
portion 56 of the present invention 1 becomes about 60% of the stress acting on the bottom of
the dent of the aforementioned peripheral portion 56 of the comparative example 1. The stress
acting on the bottom of the dent of the peripheral portion 56 of the product 2 of the present
invention is about 50% of the stress acting on the bottom of the dent of the peripheral portion 56
of the comparative example 1 The stress acting on the bottom of the dent of the peripheral
portion 56 described above is about 80% of the stress acting on the bottom of the dent of the
peripheral portion 56 described in Comparative Example 1.
For this reason, in the invention products 1, 2 and 3, the center cap 16 is less likely to be
deformed than the comparative example 1, and it can be suppressed that the center cap 16 is
deformed and abnormal noise is generated when the diaphragm 15 vibrates. It became clear.
[0058]
In FIG. 7 and FIG. 8, the same parts as those of the above-described embodiment are indicated by
the same reference numerals and the description thereof is omitted. In FIG. 7, the center cap
reinforcing plate 57 is formed of foamed acrylic as a foamed resin, and is formed in a plate shape
having a constant thickness. In FIG. 7, the reinforcing plate main body 58 is formed so as not to
be in contact with the entire back surface 53 b of the cap main body 53, and the projecting
portion 59 is not provided.
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[0059]
In FIG. 8, the center cap reinforcing plate 57 is made of polypropylene as a resin by injection
molding. In FIG. 8, the reinforcing plate main body 58 is formed in a thin plate shape so as to be
in close contact with the entire back surface 53 b of the cap main body 53, and a projecting
portion 59 protruding from the reinforcing plate main body 58 in the opposite direction to the
acoustic radiation direction is provided. There is. The projecting portion 59 integrally extends at
the center of the reinforcing plate main body 58, and linearly extends in the radial direction of
the reinforcing plate main body 58. The plurality of protrusions 59 are provided such that the
angle between the protrusions 59 adjacent to each other is 45 degrees.
[0060]
In the embodiment described above, two drive cones 14 and 15 and edges 17 and 18 are
provided, but in the present invention, one or three or more drive cones 14 and 15 and edges 17
and 18 may be provided. In the embodiment described above, two voice coils 12 are provided,
and four tinsel wires 36 and four lead wires 37 are provided. However, in the present invention,
one or three or more voice coils 12 may be provided, and two or four or more tinsel wires 36 and
two or more lead wires 37 may be provided.
[0061]
In the above-described embodiment, the center portion 16 of the center cap 16 is formed in a
convex shape in the acoustic radiation direction, and the concave cross-sectional portion 63 is
formed from the center portion 55 to the outer edge portion. The shape of the center cap 16 is
not particularly limited to the shape of the embodiment described above.
[0062]
For example, in the present invention, as shown in FIGS. 9 and 10, the center cap 16 may have a
rib 64 formed on the back surface 53b.
However, parts common to the above-described embodiment are denoted by the same reference
numerals, and the description thereof is omitted.
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[0063]
In the speaker 1 shown in FIG. 9, on the back surface 53b (see FIG. 10) of the center cap 16, a
plurality of ribs 64 linearly extending radially from the central portion 55 toward the outer edge
portion are formed. Further, as shown in FIG. 10, the rib 64 is disposed along the concave cross
section 63 of the center cap 16. Furthermore, the plurality of ribs 64 are spaced apart from one
another in the circumferential direction of the center cap 16.
[0064]
The center cap 16 shown in FIG. 9 has a concave cross-sectional portion 63 as compared with a
simple shape in which the central portion 55 is formed in a convex shape in the acoustic
radiation direction, so the rigidity is increased and vibration is generated. Even if the plate 15 is
vibrated to a large extent, the occurrence of dents on the outer surface 53a can be suppressed.
[0065]
Further, since the rib 64 formed on the back surface 53b of the center cap 16 is provided along
the concave cross section 63, the rigidity of the concave cross section 63 can be increased, and
the diaphragm 15 is vibrated with a large amplitude. At the same time, it is possible to suppress
the occurrence of dents in the center cap 16.
[0066]
Further, in order to increase the rigidity of the center cap 16 shown in FIGS. 9 and 10, the center
cap reinforcing plate 57 described in the above-described embodiment may be attached to the
back surface 53b.
[0067]
Further, in the present invention, as shown in FIG. 11, a convex cross section 65 may be further
formed between the concave cross section 63 and the outer edge of the center cap 16 (however,
the embodiment described above). The same parts as in (1) will be assigned the same reference
numerals and explanations thereof will be omitted).
The convex cross-sectional portion 65 is disposed on the outer periphery of the concave cross-
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sectional portion 63, and is formed in a convex shape in the acoustic radiation direction.
Also in the case shown in FIG. 11, the outer surface 53a of the center cap 16 is of course formed
in a gentle curved surface.
[0068]
Furthermore, in the present invention, although not shown, a concave cross section may be
further formed between the convex cross section 65 and the outer edge, and the phase difference
with each sound wave generated from the center cap 16 is substantially the same. Thus, it is
possible to use a shape close to a flat shape.
Also in these cases, the center cap reinforcing plate 57 may be attached or the rib 64 may be
formed.
[0069]
According to the embodiment described above, the following speaker 1 can be obtained.
[0070]
(Supplementary Note) A frame 4, a magnetic circuit unit 2 supported by the frame 4, and a
vibrating unit 3 supported by the frame 4. The vibrating unit 3 includes a voice coil 12 to which
an audio current is supplied. The diaphragm 15 vibrates by the driving force acting on the voice
coil 12, and the center cap 16 attached to the diaphragm 15. The central portion 55 of the center
cap 16 is convexly directed in the acoustic radiation direction. The concave section 63 is formed
from the center section 55 to the outer edge of the center cap 16, and the outer surface 53 a of
the center cap 16 is formed to have a gentle curved surface. A speaker 1 characterized in that a
center cap reinforcing plate 57 is attached to the back surface 53b.
[0071]
Since the center cap reinforcing plate 57 is attached to the back surface 53b of the center cap 16
according to the remark, the projecting portion is integrally provided on the back surface 53b
side of the center cap 16 to make a sink or the like on the outer surface 53a. It is possible to
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improve the mechanical strength of the center cap 16 and prevent the center cap 16 from
vibrating together with the diaphragm 15 without loss.
Therefore, it is possible to prevent the center cap 16 from generating noise when the diaphragm
15 vibrates.
[0072]
In addition, the Example mentioned above only showed the typical form of this invention, and
this invention is not limited to an Example.
That is, various modifications can be made without departing from the scope of the present
invention.
[0073]
It is a sectional view of a speaker concerning one example of the present invention. It is a
perspective view of the center cap of the speaker shown by FIG. It is the perspective view seen
from the back side of the center cap shown by FIG. It is sectional drawing in alignment with the
IV-IV line in FIG. (A) is a front view of the center cap reinforcement board affixed on the center
cap shown by FIG. 3, (b) is sectional drawing in alignment with the VB-VB line | wire in Fig.5 (a).
It is explanatory drawing which shows the change of the stress which acts on the bottom of the
dent of this invention goods 1 and 2 and comparative example 1 and 2. FIG. (A) is a front view of
the modification of the center cap reinforcement board shown by FIG. 5, (b) is sectional drawing
in alignment with the VIIB-VIIB line | wire in FIG. 7 (a). (A) is a side view of the other modification
of the center cap reinforcement board shown by FIG. 5, (b) is the top view seen from the arrow
VIIIB direction in Fig.8 (a). It is sectional drawing of the speaker concerning the other Example of
this invention. It is the perspective view seen from the back side of the center cap with which the
speaker shown by FIG. 9 is equipped. FIG. 10 is a cross-sectional view of a loudspeaker according
to still another embodiment of the present invention.
Explanation of sign
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[0074]
Reference Signs List 1 speaker 2 magnetic circuit portion 3 vibration portion 4 frame 12 voice
coil 14 drive cone 15 vibration plate 16 center cap 53 a outer surface 53 b back surface 55
central portion 56 peripheral portion 57 center cap reinforcing plate 58 reinforcing plate main
body 59 projecting portion 63 concave section 64 rib 65 convex cross section K space
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