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JP2006013587

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DESCRIPTION JP2006013587
PROBLEM TO BE SOLVED: To provide a speaker device which realizes high quality sound
reproduction by suppressing vibration of a magnetic circuit. SOLUTION: A speaker device
suitable for use in vehicles is generated by a main circuit portion that performs a main function
of emitting a sound wave to the sound output side, and a magnetic circuit due to vibration of a
vibration system of the main portion during driving. It has a vibration suppression unit that
suppresses vibration. The voice coil of the main body portion and the voice coil of the vibration
suppression portion are wound in opposite directions, and the effective wire lengths of the voice
coil of the main body portion and the voice coil of the vibration suppression portion are
respectively set equal. When a current (electric signal) of the same phase and the same
magnitude is applied to the voice coils of the main body and the vibration suppressing portion,
the voice coil bobbin of the main body and the voice coil bobbins of the vibration suppressing
portion are the same in opposite directions. Because they move by the force of, the opposite
reaction acts on the common magnetic circuit and they mutually cancel each other. For this
reason, it can suppress that a vibration arises in a magnetic circuit, and can prevent that noise
generate | occur | produces from the attachment part to the cabinet for vehicles, etc. of a speaker
apparatus. [Selected figure] Figure 1
Speaker device
[0001]
The present invention relates to a method of suppressing vibration of a speaker device.
[0002]
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1
2. Description of the Related Art An on-vehicle speaker device is conventionally known that
includes a magnetic circuit having a yoke, a magnet and a pole piece, and a vibration system
having a voice coil bobbin, a voice coil, a diaphragm and a frame.
In such a speaker device, a frame having a function of supporting a magnetic circuit or a
vibration system is attached to a mounting portion such as a cabinet or a door.
[0003]
However, in such a speaker device, since the frame is attached to a mounting portion such as a
cabinet, the following problems occur. In such a speaker device, when the voice coil bobbin
moves in the axial direction, the magnetic circuit receives the reaction force. For this reason,
vibration occurs in the magnetic circuit. And the vibration which generate | occur | produced in
the magnetic circuit is further transmitted to attachment parts, such as a cabinet, via a flame |
frame. For this reason, in such a speaker device, since sound waves (disturbing sound waves)
other than the sound waves emitted from the diaphragm are emitted from the mounting portion
such as the cabinet, there is a problem that high quality sound reproduction can not be realized.
[0004]
As a speaker device capable of eliminating this kind of defect, for example, by using a single
speaker, by attaching a vibrating body consisting of a movable body and a weight to the yoke
constituting the speaker, the reaction caused by the diaphragm is eliminated. There is known a
speaker device that prevents the swing of the speaker box (see, for example, Patent Document 1).
[0005]
Also, by using a single speaker in the same manner as described above, by attaching a vibrating
body that doubles as a cap on the top of the voice coil bobbin constituting the speaker or on the
inclined portion of the cone inner periphery of the vibrating plate, the reaction caused by the
vibrating plate is eliminated. There is known a speaker device in which the swing of the speaker
box is suppressed (see, for example, Patent Document 2).
[0006]
Also, by using a single speaker as described above and attaching a vibrating body consisting of a
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2
movable body, a weight and an outer ring on the gasket that constitutes the speaker, the reaction
caused by the diaphragm is eliminated and the swing of the speaker box is suppressed. A speaker
device designed to do this is known (see, for example, Patent Document 3).
[0007]
There is also known a speaker device in which a vibration associated with a reaction reaction of
the movement of the diaphragm is suppressed by mounting a weight on the back side of the
magnetic circuit (see, for example, Patent Document 4).
There is also known a speaker device capable of increasing the sound pressure in the low range
and making the reaction force between the upper and lower sides and the left and right sides of
the speaker box cancel each other (see, for example, Patent Document 5).
[0008]
JP-A 2000-59879 JP-A 11-346399 JP-A 2000-41279 JP-A 2002-152884 JP-A 2000-23275
[0009]
As problems to be solved by the present invention, the above-mentioned ones can be mentioned
as an example.
An object of the present invention is to provide a speaker device which realizes high-quality
sound reproduction by suppressing vibration of a magnetic circuit.
[0010]
The invention according to claim 1 is a speaker device, including a first magnetic circuit and a
first vibration unit driven by the first magnetic circuit, and emitting a sound wave to the sound
output side A second magnetic circuit driven in a direction opposite to the first vibrating unit by
the main body having a function, a second magnetic circuit integrally formed with the first
magnetic circuit, and the second magnetic circuit And a vibration suppression unit having a
vibration unit, wherein the second vibration unit is configured to cause the second magnetic
circuit to perform a vibration that cancels the vibration given by the first vibration unit to the
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first magnetic circuit. It is characterized by giving.
[0011]
In a preferred embodiment of the present invention, the speaker device has a first magnetic
circuit and a first vibration unit driven by the first magnetic circuit, and has a function of
emitting an acoustic wave to the sound output side. A second vibration circuit driven in a
direction opposite to the first vibration unit by the second magnetic circuit integrally formed with
the first magnetic circuit, and the second magnetic circuit integrally formed with the first
magnetic circuit; And the second vibration unit gives the second magnetic circuit a vibration that
cancels the vibration given by the first vibration unit to the first magnetic circuit.
[0012]
The above speaker device has a first magnetic circuit and a first vibrating portion, and includes a
main body having a function of emitting a sound wave on the sound output side.
By driving the first magnetic circuit, the first vibration unit can be driven to emit a sound wave to
the sound output side.
The speaker device further includes a second magnetic circuit integrally formed with the first
magnetic circuit, and a second vibration unit driven in a direction opposite to the first vibration
unit by the second magnetic circuit. The vibration suppression part which it has is provided.
By driving the second magnetic circuit, the second vibration unit can be driven in the direction
opposite to the driving direction of the first vibration unit.
Since the first magnetic circuit and the second magnetic circuit are integrally formed, magnetic
fields of substantially the same magnitude are formed in the corresponding magnetic gaps.
[0013]
In this speaker device, when only the first vibrating portion of the main body portion is driven,
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the reaction generates vibration in the first and second magnetic circuits. Therefore, when the
speaker device is attached to a mounting portion such as a vehicle cabinet via a frame, for
example, vibrations generated by the first and second magnetic circuits are transmitted to the
mounting portion via the frame. Unnecessary sound waves (disturbing sound waves) are emitted
from the attachment to the sound emitting side. As a result, high quality sound reproduction can
not be realized.
[0014]
However, in this speaker device, the second vibration unit applies, to the second magnetic circuit,
a vibration that cancels the vibration that the first vibration unit applies to the first magnetic
circuit. Therefore, in the first and second magnetic circuits, the force (vibration) generated by the
reaction with the drive of the first vibration unit, and the force generated by the reaction with the
drive of the second vibration unit ( The vibration) can be mutually canceled to suppress the
occurrence of vibration in the first and second magnetic circuits. Therefore, when the speaker
device is attached to an attachment portion such as a vehicle cabinet via a frame, for example,
transmission of vibration from the first and second magnetic circuits to the attachment portion
can be suppressed. Therefore, it can suppress that an unnecessary sound wave (interference
sound wave) is radiated | emitted from the attachment part to the sound emission side. Thereby,
high quality sound reproduction can be realized.
[0015]
In one aspect of the above speaker device, the second vibration unit has a reaction in the same
size and a reverse direction as the reaction given to the first magnetic circuit by the vibration of
the first vibration unit. Give to 2 magnetic circuits. Since the first magnetic circuit and the second
magnetic circuit are integrally formed, the forces applied to the magnetic circuit cancel each
other and the vibration of the magnetic circuit is prevented. In a preferred embodiment, the first
and second magnetic circuits are constituted by the same pole piece, magnet and plate.
[0016]
In another aspect of the above speaker device, the first vibration unit includes a first voice coil
bobbin, a first voice coil, a first damper, and a diaphragm, and the second vibration is provided.
The unit includes a second voice coil bobbin, a second voice coil, a second damper, and a dummy
weight.
01-05-2019
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[0017]
According to this aspect, since the first vibration unit includes the first voice coil bobbin, the first
voice coil, the first damper, and the diaphragm, it is possible to drive the first magnetic circuit by
driving the first magnetic circuit. The vibration unit 1 can be driven in the axial direction of the
speaker device.
Thereby, the sound wave can be emitted through the diaphragm to the sound output side. On the
other hand, the second vibration unit includes a second voice coil bobbin, a second voice coil, a
second damper, and a dummy weight. Therefore, by driving the second magnetic circuit, the
second vibration unit can be driven in the axial direction of the speaker device. Further, since the
dummy weight is provided, the mass of the second vibrating portion can be changed by adjusting
the weight of the dummy weight. In a preferred example, the dummy weight can be set to a
weight such that the mass of the first vibrating portion and the mass of the second vibrating
portion are the same. This makes it possible to drive the first vibrating unit and the second
vibrating unit with the same force. In addition, since a diaphragm is not provided in the 2nd
vibration part, an unnecessary sound wave is not generated from the 2nd vibration part.
[0018]
In another aspect of the above speaker device, the first voice coil and the second voice coil have
the same effective wire length and are wound in relatively opposite directions, It further
comprises a signal supply circuit that supplies the same electrical signal to the voice coil and the
second voice coil.
[0019]
In this aspect, the first voice coil and the second voice coil have the same effective wire length
and are wound in opposite directions.
Further, since the magnetic flux densities of the first magnetic circuit and the second magnetic
circuit are substantially the same, the first vibrating portion and the second vibrating portion are
driven in the opposite direction by the force of the same magnitude. This prevents vibrations
occurring in the magnetic circuit.
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[0020]
In a preferred embodiment of the above speaker device, the dummy weight has the same mass as
the diaphragm of the first vibrating portion. As a result, the weight of the first vibrating unit and
the mass of the second vibrating unit can be equalized, and the first vibrating unit and the second
vibrating unit can be driven with the same force. It becomes.
[0021]
In another aspect of the above speaker device, the main body portion and the vibration
suppression portion are respectively set to the same lowest resonance frequency. As a result, it is
possible to suppress the occurrence of vibration in the first and second magnetic circuits over the
entire band of the reproducible frequency of the speaker device.
[0022]
Hereinafter, preferred embodiments of the present invention will be described with reference to
the drawings. The present invention is to suppress the vibration of the magnetic circuit in the
speaker device. In the embodiment of the present invention, a plurality of sets of magnetic
circuits and vibration systems are provided, and one of them is made to function as vibration
suppression means of the magnetic circuit. This suppresses the vibration generated in the
magnetic circuit when the speaker device is driven. In addition, when this speaker device is
attached to an attachment portion such as a vehicle cabinet via a frame, for example, the
vibration suppressing means is functioned to cause the vibration generated in the magnetic
circuit to be attached via the frame. Prevent it from being transmitted to As a result, the sound
wave (disturbing sound wave) other than the sound wave emitted from the diaphragm is
suppressed from being emitted from the mounting portion to the sound emission side, and highquality sound reproduction is realized.
[0023]
First Embodiment (Configuration of Speaker Device) FIG. 1 schematically shows a schematic
configuration of a speaker device 100 according to a first embodiment of the present invention.
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FIG. 1 shows a cross-sectional view of the speaker device 100 taken along a plane including the
central axis. Hereinafter, the configuration and the like of the speaker device 100 according to
the first embodiment will be described with reference to FIG.
[0024]
The speaker device 100 has a main body that performs a main function of emitting a sound wave
to the sound output side, and a vibration suppression portion that cancels vibration generated in
the magnetic circuit due to vibration of the vibration system of the main body during driving.
And other members. The speaker device 100 can be suitably used in a state of being attached to
a mounting portion such as a cabinet or a door as a vehicle speaker.
[0025]
The main body includes a magnetic circuit 50 having a yoke 1a and a center pole 1b which are
components of the pole piece 1, a magnet 2 and a plate 3, a voice coil bobbin 4, a voice coil 5, a
damper 6, a frame 7, a diaphragm 8 and And a vibration system 60 having a dustproof cap 9.
[0026]
First, the configuration of the magnetic circuit 50 of the main unit will be described.
[0027]
The pole piece 1 has a substantially cylindrical center pole 1b formed substantially at the center,
a substantially cylindrical yoke 1c formed at a predetermined distance from the center pole 1b,
and a lower end of the center pole 1b. And a yoke 1a having a flange shape formed between the
lower portion and the lower portion of the yoke 1c.
Among the components of the pole piece 1, the yoke 1 a and the center pole 1 b constitute a
magnetic circuit 50 together with the magnet 2 and the plate 3.
[0028]
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The magnet 2 has a substantially annular shape, and is disposed at a position overlapping on the
yoke 1a.
The plate 3 has a substantially annular shape, and is disposed at the overlapping position on the
magnet 2.
[0029]
In the magnetic circuit 50, a magnetic circuit is mainly formed by the magnet 2, the plate 3, the
yoke 1a and the center pole 1b, and the magnet gap 30 formed between the inner peripheral
wall of the plate 3 and the outer peripheral wall of the center pole 1b is a magnet The magnetic
flux of 2 is concentrated.
[0030]
Next, the configuration of the vibration system 60 of the main body will be described.
[0031]
The voice coil bobbin 4 has a substantially cylindrical shape.
The vicinity of the lower end portion of the outer peripheral wall of the voice coil bobbin 4 is
opposed to the inner peripheral wall of the plate 3 at a constant distance.
On the other hand, the vicinity of the lower end portion of the inner peripheral wall of the voice
coil bobbin 4 is opposed to the outer peripheral wall of the center pole 1b at a constant interval.
An air gap (magnetic gap 30) is formed between the outer peripheral wall of the center pole 1b
and the inner peripheral wall of the opposing plate 3.
[0032]
The voice coil 5 is wound around the lower end of the outer peripheral wall of the voice coil
bobbin 4. The voice coil 5 is wound around the voice coil bobbin 4 with a fixed winding width
and a fixed direction, which will be described later. The voice coil 5 has a plus / minus lead wire
01-05-2019
9
(not shown). The lead on the positive side is an input wiring of the L (or R) channel signal, and
the lead on the negative side is an input wiring of the ground (GND: ground) signal. Each lead is
electrically connected to a terminal (not shown) provided on the frame 7. An electric signal for
one channel is input to the voice coil 4 from the side of an amplifier (not shown) via each
terminal.
[0033]
The damper 6 has a substantially ring shape, and has an elastic portion formed by concentrically
forming a plurality of corrugations. The damper 6 movably supports the voice coil bobbin 4. The
inner peripheral edge portion of the damper 6 is fixed in the vicinity of the upper end portion of
the outer peripheral wall of the voice coil bobbin 4. On the other hand, the outer peripheral edge
portion of the damper 6 is fixed on the second flange portion 7 b provided on the frame 7.
[0034]
Various components of the speaker device 100 are fixed to the frame 7 and serve to support the
speaker device 100. The frame 7 can be made of various materials, but in order to reduce its
weight, it is preferable to use a resin material. The frame 7 has a first flange portion 7a, a second
flange portion 7b, and a third flange portion 7c.
[0035]
The first flange portion 7 a is formed at the lower end portion of the frame 7. The first flange
portion 7a has an opening 7ab at a position where a projection 1ca of a yoke 1c described later
is inserted. The projection 1ca is inserted into the opening 7ab, and the frame 7 is fixed to the
yoke 1c in a state where the upper portion of the projection 1ca is crimped by a caulking device
(not shown). The second flange 7 b is formed at an upper position near the first flange 7 a. The
outer peripheral edge portions of the dampers 6 and 12 are respectively mounted on the second
flange portion 7b. For this reason, the second flange portion 7 b plays a role of supporting the
dampers 6 and 12. The third flange portion 7 c is formed at the upper end portion of the frame
7. The outer peripheral edge portion of the diaphragm 8 is attached onto the third flange portion
7c. For this reason, the third flange portion 7 c plays a role of supporting the diaphragm 8.
01-05-2019
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[0036]
The diaphragm 8 is a so-called cone-shaped diaphragm, and is bonded and joined to a separate
edge portion 8a, or is integrally formed with the edge portion 8a. Various materials such as
paper-based, polymer-based, and metal-based can be applied to the diaphragm 8 in accordance
with various applications. The outer peripheral edge portion of the edge portion 8a is fixed on
the third flange portion 7c formed on the upper end portion of the frame 7 as described above.
On the other hand, the inner peripheral edge portion of the diaphragm 8 is fixed in the vicinity of
the upper end portion of the outer peripheral wall of the voice coil bobbin 4.
[0037]
The dustproof cap 9 has a substantially dome shape and is attached to a position near the inner
peripheral edge of the diaphragm 8 on the sound output side. The dustproof cap 9 has a function
of preventing foreign matter such as dust from invading the inside of the speaker device 100.
[0038]
In the main body described above, when an electric signal is input from the amplifier to the
terminal, the electric signal is supplied to the voice coil 5 through the lead wires of the voice coil
5. As a result, driving force is generated in the voice coil 5 in the magnetic gap 30, and the
diaphragm 8 is vibrated in the axial direction of the speaker device 100. Thereby, the diaphragm
8 emits a sound wave to the sound emission side.
[0039]
On the other hand, the vibration suppression unit includes the magnetic circuit 51 including the
yoke 1 a and the yoke 1 c which are components of the pole piece 1, the magnet 2 and the plate
3, the voice coil bobbin 10, the voice coil 11, the damper 12 and the dummy weight 13. And a
vibration system 61 having
[0040]
First, the configuration of the magnetic circuit 51 of the vibration suppression unit will be
described.
01-05-2019
11
[0041]
The yoke 1 a and the yoke 1 c which are components of the pole piece 1 constitute a magnetic
circuit 51 together with the magnet 2 and the plate 3.
[0042]
The configuration of the yoke 1a is as described above.
The yoke 1c extends from the vicinity of the outer peripheral edge of the yoke 1a toward the
sound output side and has a substantially cylindrical shape.
On the upper end face of the yoke 1c, the above-described substantially cylindrical projection
1ca is formed.
The configurations of the magnet 2 and the plate 3 are as described above.
[0043]
In the magnetic circuit 51, a magnetic circuit is mainly constituted by the magnet 2, the plate 3,
the yoke 1a and the yoke 1c, and the magnetic gap 31 formed between the outer peripheral wall
of the plate 3 and the inner peripheral wall of the yoke 1c is It concentrates the magnetic flux. As
described above, since the magnetic circuit 50 of the main body and the magnetic circuit 51 of
the vibration suppression unit are integrally formed, the magnetic gaps 30 and 31 corresponding
to them form magnetic fields of substantially the same magnitude. There is.
[0044]
Next, the configuration of the vibration system 61 of the vibration suppression unit will be
described.
[0045]
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12
The voice coil bobbin 10 has a substantially cylindrical shape, and has a diameter larger than
that of the voice coil bobbin 4.
The vicinity of the lower end portion of the outer peripheral wall of the voice coil bobbin 10 is
opposed to the inner peripheral wall of the yoke 1 c at a constant distance. On the other hand,
the vicinity of the lower end portion of the inner peripheral wall of the voice coil bobbin 10 is
opposed to a part of the outer peripheral wall of the magnet 2 and the outer peripheral wall of
the plate 3 at a constant interval. An air gap (magnetic gap 31) is formed between the inner
peripheral wall of the yoke 1c and the outer peripheral wall of the opposing plate 3.
[0046]
The voice coil 11 is wound around the lower end portion of the outer peripheral wall of the voice
coil bobbin 10. The voice coil 11 is wound around the voice coil bobbin 10 with a fixed winding
width and a fixed direction, which will be described later. The voice coil 11 has a plus / minus
lead wire (not shown). The lead on the positive side is an input wiring of the L (or R) channel
signal, and the lead on the negative side is an input wiring of the ground (GND: ground) signal.
Each lead is electrically connected to a terminal (not shown) provided on the frame 7. An electric
signal for one channel is input to the voice coil 11 from the side of an amplifier (not shown) via
each terminal.
[0047]
The damper 12 has a substantially ring shape, and has an elastic portion formed by
concentrically forming a plurality of corrugations. The damper 12 movably supports the voice
coil bobbin 10. The inner peripheral edge portion of the damper 12 is fixed in the vicinity of the
upper end portion of the outer peripheral wall of the voice coil bobbin 10. On the other hand, the
outer peripheral edge portion of the damper 12 is fixed on the second flange portion 7 b
provided on the frame 7.
[0048]
The dummy weight 13 plays a role as a weight in the vibration suppression unit. The dummy
01-05-2019
13
weight 13 is a mass obtained by adding the additional mass of air to the weight of the vibration
system, specifically, the weight such that the vibration system 60 of the main body and the
vibration system 61 of the vibration suppression unit have the same mass. It is set. The dummy
weight 13 has a substantially ring shape, and has a diameter substantially the same as the
diameter of the voice coil bobbin 10. The dummy weight 13 is attached to the upper end portion
of the voice coil bobbin 10. In addition, various materials such as paper-based, polymer-based,
and metal-based can be applied to the dummy weight 13.
[0049]
In the vibration suppression unit described above, when an electrical signal is input from the
amplifier to the terminal unit, the electrical signal is supplied to the voice coil 11 through the
lead wires of the voice coil 11. As a result, a driving force is generated in the voice coil 11, and
the voice coil bobbin 10 and the like vibrate in the axial direction of the speaker device 100. In
addition, since a diaphragm is not provided in the vibration suppression part, even if the
vibration system 61 vibrates, an unnecessary sound wave will not generate | occur | produce.
[0050]
As other members, a fixing screw 72 and the like can be mentioned. The fixing screw 72 has a
function of fixing the speaker device 100 to the mounting portion 70 such as a cabinet for a
vehicle. Specifically, the fixing screw 72 fixes the third flange portion 7 c of the frame 7 and the
mounting portion 70. Thus, the speaker device 100 is fixed to the mounting portion 70 via the
fixing screw 72.
[0051]
(Method of Suppressing Vibration of Magnetic Circuit) First, prior to describing the method of
suppressing vibration of a magnetic circuit according to the first embodiment of the present
invention, vibration is generated in a magnetic circuit or the like with reference to a speaker
device according to a comparative example. Explain the principle. FIG. 2 shows a cross-sectional
view of the speaker device 500 according to the comparative example, cut along a plane
including the central axis.
01-05-2019
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[0052]
The speaker device 500 according to the comparative example has substantially the same
configuration as the speaker device 100 according to the first embodiment. However, the former
is different from the latter in that it is composed of a single magnetic circuit and a vibration
system, and does not have a vibration suppressor. Therefore, in the following, the same
components as those of the speaker device 100 according to the first embodiment are denoted
by the same reference numerals, and the description thereof is omitted.
[0053]
In the speaker device 500, when an electric signal is input to the voice coil 5 from the amplifier
via the terminal portion, the voice coil bobbin 4 moves in the axial direction of the speaker device
500, that is, in the arrow Y1 direction and the arrow Y2 direction. Therefore, the magnetic circuit
55 including the pole piece 1, the magnet 2 and the plate 3 moves in the direction opposite to
the moving direction of the voice coil bobbin 4 under the reaction force. Specifically, when the
voice coil bobbin 4 moves in the arrow Y1 direction, the magnetic circuit 55 receives the reaction
force and moves in the arrow Y4 direction opposite to the arrow Y1 direction. On the other hand,
when the voice coil bobbin 4 moves in the arrow Y 2 direction, the magnetic circuit 55 receives
the reaction force and moves in the arrow Y 3 direction opposite to the arrow Y 2 direction. As
described above, since the magnetic circuit 55 receives the reaction force as the voice coil bobbin
4 moves, vibration occurs in the magnetic circuit 55. The vibration generated in the magnetic
circuit 55 is transmitted to the frame 7 as indicated by the arrow Y7, and the vibration
transmitted to the frame 7 is further transmitted to the mounting portion 70 such as a cabinet
for a vehicle. Therefore, in the speaker device 500, the attachment portion 70 vibrates at the
time of driving, and an unnecessary sound wave (other than the direct sound emitted from the
diaphragm 8) in the direction shown by the arrow Y8 from the attachment portion 70,
Interference sound waves) are emitted. Accordingly, it is difficult for the speaker device 500 to
realize high-quality sound reproduction.
[0054]
Next, a method of suppressing vibration of the magnetic circuits 50 and 51 by the speaker device
100 according to the first embodiment will be described.
[0055]
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In the speaker device 100 according to the first embodiment, when the voice coil bobbin 4 moves
in the vertical direction of the speaker axis, the magnetic circuits 50 and 51 receive the reaction
force.
For this reason, in the magnetic circuits 50 and 51, vibration occurs as the voice coil bobbin 5
moves. In order to suppress the vibration generated by such magnetic circuits 50 and 51, a
mechanism is provided which moves in the opposite direction to the moving direction of the
voice coil bobbin 4 and with the same force, and the mechanism simultaneously with the driving
of the voice coil bobbin 4 Drive. Thereby, in the magnetic circuits 50 and 51, the force (vibration)
generated by the reaction with the movement of the voice coil bobbin 4 and the force (vibration)
generated by the reaction with the movement of the voice coil bobbin 10 cancel each other. It is
possible to suppress the occurrence of vibration in the magnetic circuits 50 and 51.
[0056]
Therefore, in the speaker device 100, a vibration suppression unit is provided as one
corresponding to the above-described mechanism, and the vibration suppression unit is
simultaneously operated when the main unit is operated. However, in this case, the abovedescribed effects of the present invention can not be obtained unless the voice coil bobbin 4 of
the main body portion and the voice coil bobbin 10 of the vibration suppression portion move in
opposite directions with the same force.
[0057]
Therefore, in the speaker device 100, the effective wire lengths of the voice coil 5 and the voice
coil 11 are made equal, and the winding direction of the voice coil 5 on the voice coil bobbin 4
and the winding direction of the voice coil 11 on the voice coil bobbin 10 are It is in the opposite
relationship. The former can move the voice coil bobbin 4 and the voice coil bobbin 10 with the
same force, and the latter can move the voice coil bobbin 4 and the voice coil bobbin 10 in
opposite directions.
[0058]
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16
Here, the effective wire length and the winding direction of the voice coils 5 and 11 will be
described with reference to FIGS. 3 and 4. FIG. 3 shows a partial plan view of the state where the
voice coils 5 and 11 etc. in FIG. 1 are observed from the sound output side to the back side. In
FIG. 3, for the sake of convenience, the minimum components are shown. FIG. 4 is a partial plan
view corresponding to FIG. 3 and shows a modification in which the winding direction of the
voice coil 5 with respect to the voice coil bobbin 4 and the winding direction of the voice coil 11
with respect to the voice coil bobbin 10 are respectively set to the same direction. .
[0059]
First, the effective wire lengths of the voice coils 5 and 11 will be described.
[0060]
In general, the force "F" generated in the voice coil is expressed by the following equation: F (N) =
B (T) × L (m) × I (A) (Equation 1)
Here, “B” indicates the magnetic flux density of the magnetic circuit, “L” indicates the
effective wire length of the voice coil, and “I” indicates the current applied to the voice coil. In
the above equation 1, the parentheses indicate physical quantities (units).
[0061]
In order to move the voice coil 5 and the voice coil 11 with the same force, the force "F1" of the
voice coil 5 and the force "F2" of the voice coil 11 are respectively equal to each other according
to the above equation 1. It should be adjusted to become
[0062]
Therefore, first, considering the magnetic flux density "B" which is one of the parameters, since
the magnetic circuit 50 and the magnetic circuit 51 have substantially the same configuration of
the magnetic circuit, the magnetic flux density "B1" of the magnetic circuit 50 and the magnetic
circuit 51 The magnetic flux density "B2" is substantially the same.
Thus, it is not necessary to adjust the magnetic flux density "B" in equation 1 above.
01-05-2019
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[0063]
Next, for the current “I” which is one of the parameters, in order to make the current “I1”
applied to the voice coil 5 and the current “I2” applied to the voice coil 11 identical, It suffices
to supply a signal. That is, an audio signal to be reproduced may be supplied to the voice coils 5
and 11. As described above, since the vibration suppression unit is not provided with the
diaphragm, the vibration suppression unit does not emit a sound wave even if an audio signal is
supplied.
[0064]
Next, the effective wire length “L” of the voice coil, which is one of the parameters, is
examined. As shown in FIG. 3, the radius r 2 of the voice coil bobbin 10 is larger than the radius r
1 of the voice coil bobbin 4. Therefore, in order to make the effective wire length "L11" of the
voice coil 5 with respect to the voice coil bobbin 4 and the effective wire length "L12" of the
voice coil 11 with respect to the voice coil bobbin 10 respectively equal, It is necessary to adjust
the number of turns of the voice coil 11 with respect to the voice coil bobbin 10 and the number
of turns of the voice coil 5 with respect to the voice coil bobbin 4 respectively.
[0065]
Based on the above examination result, in the speaker device 100, the same voice signal is
applied to the voice coil 5 and the voice coil 11. Further, the number of turns of the voice coil 5
with respect to the voice coil bobbin 4 is set so that the effective line length "L11" of the voice
coil 5 with respect to the voice coil bobbin 4 and the effective line length "L12" with the voice
coil 11 with respect to the voice coil bobbin 10 are the same. And the number of turns of the
voice coil 11 with respect to the voice coil bobbin 10 are adjusted. As a result, in the speaker
device 100, the winding width "d1" of the voice coil 5 wound around the voice coil bobbin 4
becomes larger than the winding width "d2" of the voice coil 11 wound around the voice coil
bobbin 10.
[0066]
01-05-2019
18
Next, the winding direction of the voice coils 5 and 11 will be described. As shown in FIG. 3, the
voice coil 5 is wound around the voice coil bobbin 4 counterclockwise and with a constant
winding width "d1". On the other hand, the voice coil 11 is wound around the voice coil bobbin
10 clockwise and with a constant winding width "d2". For this reason, in the speaker device 100,
when current of the same phase is applied to the voice coils 5 and 11, respectively, the voice coil
bobbins 4 and 10 move in opposite directions with each other according to Fleming's left-hand
rule.
[0067]
Note that, instead of this example, the voice coil 5 is wound clockwise and around the voice coil
bobbin 4 with a fixed winding width “d1”, and the voice coil 11 is rotated counterclockwise
and with a fixed winding width “d2”. It may be wound around ten. Also in this case, when
current of the same phase is applied to the voice coils 5 and 11, respectively, the voice coil
bobbins 4 and 10 move in opposite directions to each other. That is, by making the winding
directions of the voice coil 5 and the voice coil 11 opposite to each other and applying the
current of the same phase, the direction of the reaction occurring in both coils at the time of
driving is made opposite to cancel the vibration occurring in the magnetic circuit. Can.
[0068]
Also, instead of this example, as shown in FIG. 4, the voice coil 5 is wound clockwise (or
counterclockwise) and with a constant winding width “d1” around the voice coil bobbin 4 and
the voice coil 11 clockwise. The voice coil bobbin 10 may be wound (or counterclockwise) with a
constant winding width "d2". That is, the voice coils 5 and 11 may be wound in the same
direction. However, in this case, when current of the same phase is applied to the voice coils 5
and 11, the voice coil bobbins 4 and 10 move in the same direction, respectively, according to
Fleming's left-hand rule, to obtain the effects of the present invention. Can not. Therefore, in this
case, it is necessary to apply current in reverse phase to the voice coils 5 and 11. Then, the voice
coil bobbins 4 and 10 can be moved in opposite directions to each other.
[0069]
In the speaker device 100 having the above configuration, when current (electric signal) having
01-05-2019
19
the same phase and the same magnitude is input to the voice coils 5 and 11 from the amplifier
side, the voice coil bobbins 4 and 11 are as follows: Work. When the voice coil bobbin 4 moves in
the direction of arrow Y1 with a constant force, the voice coil bobbin 10 moves in the direction
of arrow Y5 with the same force as the constant force. On the other hand, when the voice coil
bobbin 4 moves in the direction of the arrow Y2 with a constant force, the voice coil bobbin 10
moves in the direction of the arrow Y6 with the same force as the constant force.
[0070]
Thereby, in the magnetic circuits 50 and 51, the force (vibration) generated by the reaction with
the movement of the voice coil bobbin 4 and the force (vibration) generated by the reaction with
the movement of the voice coil bobbin 10 cancel each other. As a result, the generation of
vibration in the magnetic circuits 50 and 51 can be suppressed. As a result, it is possible to
effectively suppress the transmission of vibration from the magnetic circuits 50 and 51 side to
the mounting portion 70 such as a cabinet via the frame 7. Therefore, it can suppress that an
unnecessary sound wave (disturbing sound wave) is radiated | emitted from the attachment part
70 to arrow Y 8 direction shown in FIG. 1, and the speaker apparatus 100 can reproduce |
regenerate a high quality sound.
[0071]
Further, in the speaker device 100, when the lowest resonance frequency on the main body side
and the lowest resonance frequency on the vibration suppression side are different from each
other, the force (vibration) transmitted to the magnetic circuits 50 and 51 through the voice coil
bobbins 4 and 10 The size of each differs depending on the frequency band of the audio signal
that drives the speaker device. Therefore, depending on the frequency band of the audio signal,
in the magnetic circuits 50 and 51, the force (vibration) generated by the reaction with the
movement of the voice coil bobbin 4 and the reaction with the movement of the voice coil bobbin
10 are generated. The cancellation effect with the force (vibration) is reduced, and the vibration
suppression effect of the magnetic circuits 50 and 51 is reduced. Therefore, in the speaker
device 100, in order to avoid the occurrence of such a defect, the respective minimum resonance
frequencies of the main body portion and the vibration suppression portion are set to be the
same.
[0072]
01-05-2019
20
In general, the lowest resonance frequency “Fs” of the speaker device is expressed by the
following equation: Fs = (1⁄2π) × √ {(1 / Cms) × Mms} (Expression 2) Here, “Cms” indicates
compliance (reciprocal of spring constant), and “Mms” indicates moving mass (sum of
vibration system weight and added mass of air). In the above Equation 2, the unit of the lowest
resonance frequency "Fs" is (Hz), the unit of compliance "Cms" is (m / N), and the unit of moving
mass "Mms" is (g) is there.
[0073]
Therefore, in order to make the lowest resonance frequency “Fs1” of the main body and the
lowest resonance frequency “Fs2” of the vibration suppression part on the basis of the above
equation 2, for example, the compliance “Cms1” of the main body It is necessary to make the
compliance "Cms2" of the vibration suppression unit the same, and to make the moving mass
"Mms1" of the main body and the moving mass "Mms2" of the vibration suppression unit the
same.
[0074]
Therefore, in the speaker device 100, for example, the elastic performance of the elastic portion
of the damper 6 of the main body portion and the elastic performance of the elastic portion of
the damper 12 of the vibration suppression portion are adjusted to be the same. The compliance
“Cms1” of and the compliance “Cms2” of the vibration suppression unit are set to be the
same.
Further, by adjusting the weight of the dummy weight 13 provided in the vibration suppression
unit, the mass of the vibration system 60 of the main body and the mass of the vibration system
61 of the vibration suppression unit are set to be the same. There is. The additional mass of the
air of the main body portion and the additional mass of the air of the vibration suppressing
portion are also set to be the same. Thus, in the speaker device 100, the moving mass "Mms1" of
the main body and the moving mass "Mms2" of the vibration suppression unit are set to be the
same. Therefore, in the speaker device 100, the minimum resonance frequency “Fs1” of the
main body and the minimum resonance frequency “Fs2” of the vibration suppression unit are
set to be the same according to Equation 2 above.
[0075]
01-05-2019
21
Thereby, in the speaker device 100, generation of vibration in the magnetic circuits 50 and 51
can be suppressed by the above-described method of suppressing vibration of the magnetic
circuits 50 and 51 over the entire band of the reproducible frequency. Therefore, in the speaker
device 100, it is possible to suppress the emission of unnecessary sound waves (disturbing sound
waves) from the attachment portion 70 in the direction of the arrow Y8 shown in FIG. 1 over the
entire range of the reproducible frequencies. Thus, the speaker device 100 can reproduce high
quality sound over the entire band of the reproducible frequency.
[0076]
In the speaker device 100, the above-described vibration suppression method of the magnetic
circuits 50 and 51 is set to be effective below the frequency at which the frame 7 causes divided
vibration (vibration similar to rolling). The reason for this is that if the vibration of the magnetic
circuits 50 and 51 is suppressed by the vibration suppression method of the magnetic circuits 50
and 51 described above and the frame 7 causes divided vibration, the vibration is transmitted to
the magnetic circuits 50 and 51. As a result, the vibration suppression effect of the magnetic
circuits 50 and 51 is reduced.
[0077]
Second Embodiment In the speaker device 100 according to the first embodiment, the main body
is disposed on the central axis side, and the vibration suppressing portion is disposed between
the outside of the main body and the frame 7 Thus, the vibration of the magnetic circuit or the
like is suppressed, and the unnecessary sound wave is prevented from being emitted from the
mounting portion 70 such as the cabinet for the vehicle. On the other hand, in the speaker device
200 according to the second embodiment, the vibration suppressing portion is disposed on the
central axis side, and the main body portion is disposed between the outside of the vibration
suppressing portion and the frame. The same effect as that of the first embodiment can be
obtained.
[0078]
(Configuration of Speaker Device) FIG. 5 schematically shows a schematic configuration of a
speaker device 200 according to a second embodiment of the present invention. FIG. 5 shows a
01-05-2019
22
cross-sectional view of the speaker device 200 taken along a plane including the central axis. The
configuration and the like of the speaker device 200 according to the second embodiment will be
described below with reference to FIG.
[0079]
The speaker device 200 includes a main body that performs a main function of emitting a sound
wave to the sound output side, and a vibration suppression portion that suppresses vibration
generated in the magnetic circuit due to vibration of a vibration system of the main body during
driving. And other members. The speaker device 200 can be suitably used in a state of being
attached to a mounting portion such as a cabinet or a door as a vehicle speaker. The main body
includes a magnetic circuit 52 having the yoke 21a and the yoke 21c which are components of
the pole piece 21, the magnet 22 and the plate 23, the voice coil bobbin 14, the voice coil 15, the
damper 16, the frame 17, the diaphragm 18 and dustproof And a vibration system 62 having a
cap 19.
[0080]
First, the configuration of the magnetic circuit 52 of the main unit will be described.
[0081]
The pole piece 21 has a substantially cylindrical center pole 21b formed substantially at the
center, a substantially cylindrical yoke 21c formed at a predetermined distance from the center
pole 21b, and a lower end of the center pole 21b. And a yoke 21a having a flange shape formed
between the lower portion and the lower end portion of the yoke 21c.
Among the components of the pole piece 21, the yoke 21 a and the yoke 21 c constitute a
magnetic circuit 52 together with the magnet 22 and the plate 23.
[0082]
The magnet 22 has a substantially annular shape, and is disposed at a position overlapping on
the yoke 21a. The plate 23 has a substantially annular shape, and is disposed at an overlapping
01-05-2019
23
position on the magnet 22.
[0083]
In the magnetic circuit 52, a magnetic circuit is mainly formed by the magnet 22, the plate 23,
the yoke 21a and the yoke 21c, and the magnetic gap 33 formed between the outer peripheral
wall of the plate 23 and the inner peripheral wall of the yoke 21c is It concentrates the magnetic
flux.
[0084]
Next, the configuration of the vibration system 62 of the main body will be described.
[0085]
The voice coil bobbin 14 has a substantially cylindrical shape.
The vicinity of the lower end portion of the outer peripheral wall of the voice coil bobbin 14 is
opposed to the inner peripheral wall of the yoke 21 c at a predetermined interval.
On the other hand, the vicinity of the lower end portion of the inner peripheral wall of the voice
coil bobbin 14 is opposed to a part of the outer peripheral wall of the plate 23 and a part of the
outer peripheral wall of the magnet 22 at a constant interval. An air gap (magnetic gap 33) is
formed between the outer peripheral wall of the plate 23 and the inner peripheral wall of the
opposing yoke 21c.
[0086]
The voice coil 15 is wound around the lower end of the outer peripheral wall of the voice coil
bobbin 14 clockwise as viewed from the sound output side. Further, the effective wire length of
the voice coil 15 is set to the same length as the effective wire length of the voice coil 111
described later. Since the voice coil 15 is wound around the voice coil bobbin 14 having a
diameter larger than the diameter of the voice coil bobbin 110, the number of turns of the voice
coil 15 on the voice coil bobbin 14 is smaller than the number of turns of the voice coil 111 on
the voice coil bobbin 110. ing. For this reason, the winding width of the voice coil 15 is smaller
01-05-2019
24
than the winding width of the voice coil 111, which is not particularly shown in FIG.
[0087]
The damper 16 has a substantially ring shape, and has an elastic portion formed by
concentrically forming a plurality of corrugations. The damper 16 movably supports the voice
coil bobbin 14. The inner peripheral edge portion of the damper 16 is fixed in the vicinity of the
upper end portion of the outer peripheral wall of the voice coil bobbin 14. On the other hand, the
outer peripheral edge portion of the damper 16 is fixed on the second flange portion 17 b
provided on the frame 17.
[0088]
Various components of the speaker device 200 are fixed to the frame 17 and serve to support
the speaker device 200. The frame 17 has a first flange portion 17a, a second flange portion 17b,
and a third flange portion 17c.
[0089]
The first flange portion 17 a is formed at the lower end portion of the frame 17. The first flange
portion 17a has an opening 17ab at a position where a protrusion 21ca of a yoke 21c described
later is inserted. The projecting portion 21ca is inserted into the opening 17ab, and the frame 17
is fixed to the yoke 21c in a state where the upper portion of the projecting portion 21ca is
crimped by a caulking device (not shown). The second flange portion 17 b is formed at a
substantially central position of the frame 17. The outer peripheral edge portion of the damper
16 is attached onto the second flange portion 17 b. The third flange portion 17 c is formed at the
upper end portion of the frame 17. The outer peripheral edge portion of the diaphragm 18 is
attached onto the third flange portion 17c. For this reason, the third flange portion 17 c plays a
role of supporting the diaphragm 18.
[0090]
The diaphragm 18 is a so-called cone-shaped diaphragm, and is bonded and joined to a separate
01-05-2019
25
edge portion 18a, or is integrally formed with the edge portion 18a. The outer peripheral edge
portion of the edge portion 18a is fixed on the third flange portion 17c formed on the upper end
portion of the frame 17 as described above. On the other hand, the inner peripheral edge portion
of the diaphragm 18 is fixed in the vicinity of the upper end portion of the outer peripheral wall
of the voice coil bobbin 14.
[0091]
The dustproof cap 19 has a substantially dome shape and is attached to a position near the inner
peripheral edge of the diaphragm 18 on the sound output side. The dustproof cap 19 functions
to prevent foreign matter such as dust from entering the inside of the speaker device 200.
[0092]
In the main body described above, when an electric signal is input from the amplifier to the
terminal, the electric signal is supplied to the voice coil 15 through the lead wires of the voice
coil 15. As a result, driving force is generated in the voice coil 15 in the magnetic gap 33, and the
diaphragm 18 is vibrated in the axial direction of the speaker device 200. Thereby, the
diaphragm 18 emits a sound wave to the sound emission side.
[0093]
The vibration suppression unit includes a magnetic circuit 53 having a yoke 21a and a center
pole 21b, which are components of the pole piece 21, a magnet 22 and a plate 23, a voice coil
bobbin 110, a voice coil 111, a damper 112 and a dummy weight 113. And a system 63.
[0094]
First, the configuration of the magnetic circuit 53 of the vibration suppression unit will be
described.
[0095]
The yoke 21 a and the center pole 21 b which are components of the pole piece 21 constitute a
magnetic circuit 53 together with the magnet 22 and the plate 23.
01-05-2019
26
[0096]
The configurations of the yoke 21a and the center pole 21b, and the magnet 22 and the plate 23
are as described above.
[0097]
In the magnetic circuit 53, the magnet 22, the plate 23, the yoke 21a, and the center pole 21b
constitute a magnetic circuit, and the magnet gap 32 formed between the inner peripheral wall
of the plate 23 and the outer peripheral wall of the center pole 21b is a magnet 22 magnetic
fluxes are concentrated.
As described above, since the magnetic circuit 52 of the main body and the magnetic circuit 53
of the vibration suppression unit are integrally formed, magnetic fields of approximately the
same magnitude are formed in the corresponding magnetic gaps 32 and 33. There is.
[0098]
Next, the configuration of the vibration system 63 of the vibration suppression unit will be
described.
[0099]
The voice coil bobbin 110 has a substantially cylindrical shape and has a diameter smaller than
the diameter of the voice coil bobbin 14.
The vicinity of the lower end portion of the outer peripheral wall of the voice coil bobbin 110 is
opposed to the inner peripheral wall of the plate 23 at a constant distance.
On the other hand, the vicinity of the lower end portion of the inner peripheral wall of the voice
coil bobbin 110 is opposed to the outer peripheral wall of the center pole 21b at a
predetermined interval.
An air gap (magnetic gap 32) is formed between the inner peripheral wall of the plate 23 and the
01-05-2019
27
outer peripheral wall of the opposing center pole 21b.
[0100]
The voice coil 111 is wound around the lower end of the outer peripheral wall of the voice coil
bobbin 110 counterclockwise as viewed from the sound output side.
In this example, as in the first embodiment, currents (electric signals) having the same phase and
the same magnitude are applied to the voice coils 15 and 111 from the amplifier side. .
Alternatively, as described above, the voice coil 15 may be wound counterclockwise and the
voice coil 111 may be wound clockwise.
[0101]
Since the voice coil 111 is wound around the voice coil bobbin 110 having a diameter smaller
than the diameter of the voice coil bobbin 14, the number of turns of the voice coil 111 on the
voice coil bobbin 110 is larger than the number of turns of the voice coil 15 on the voice coil
bobbin 14. ing. For this reason, the winding width of the voice coil 15 is smaller than the winding
width of the voice coil 111, which is not particularly shown in FIG.
[0102]
In this example, the voice coils 15 and 111 are wound in the opposite direction, and the current
of the same phase is applied. Instead, the voice coils 15 and 111 are wound in the same
direction, and the current of the opposite phase is applied. You may do it.
[0103]
The damper 112 has a substantially ring shape, and has an elastic portion formed by
concentrically forming a plurality of corrugations.
The damper 112 movably supports the voice coil bobbin 110. The inner peripheral edge portion
of the damper 112 is fixed to the upper end portion of the outer peripheral wall of the center
01-05-2019
28
pole 21b. On the other hand, the outer peripheral edge portion of the damper 112 is fixed in the
vicinity of the upper end of the inner peripheral wall of the voice coil bobbin 110.
[0104]
The dummy weight 113 plays a role as a weight in the vibration suppression unit. The dummy
weight 113 is a mass obtained by adding the additional mass of air to the weight of the vibration
system, specifically, the weight such that the vibration system 62 of the main body portion and
the vibration system 63 of the vibration suppression portion have the same mass. It is set. The
dummy weight 113 has a substantially cap shape and is attached at a position where the top of
the voice coil bobbin 110 is closed. Various materials such as paper-based, polymer-based, and
metal-based can be applied to the dummy weight 113. Although the dummy weight has a cap
shape in this example, it may have a ring shape as in the first embodiment instead.
[0105]
In the vibration suppression unit described above, when an electrical signal is input from the
amplifier side to the terminal unit, the electrical signal is supplied to the voice coil 111 through
the lead wires of the voice coil 111. As a result, a driving force is generated in the voice coil 111,
and the voice coil bobbin 110 and the like are vibrated in the axial direction of the speaker
device 200. However, since the diaphragm wave is not provided in the vibration suppression
unit, unnecessary sound waves are not generated.
[0106]
(Method of Suppressing Vibration of Magnetic Circuit) Next, a method of suppressing the
vibration of the magnetic circuit according to the second embodiment will be described. The
vibration suppression method of the magnetic circuits 52 and 53 in the speaker device 200
according to the second embodiment is substantially the same as the vibration suppression
method of the magnetic circuit in the speaker device 100 according to the first embodiment
described above. It simplifies and explains.
[0107]
01-05-2019
29
In the speaker device 200, when an electric signal is input to the voice coil 15 from the amplifier
side via the terminal portion, the voice coil bobbin 14 moves in the axial direction of the speaker
device 200, that is, in the arrow Y1 direction and the arrow Y2 direction. At this time, if the
vibration suppressing method of the magnetic circuits 52 and 53 according to the second
embodiment is not applied, the magnetic circuits 52 and 53 move in the direction opposite to the
moving direction of the voice coil bobbin 14 under the reaction force. . Then, the vibration
generated in the magnetic circuits 52 and 53 is further transmitted to the mounting portion 70
such as a cabinet for a vehicle via the frame 17, and an unnecessary sound wave (disturbing
sound wave) is transmitted from the mounting portion 70 in the arrow Y8 direction. It is emitted.
[0108]
Therefore, in the speaker device 200 according to the second embodiment, as in the speaker
device 100 according to the first embodiment, when the main body portion is operated, the
vibration suppression unit is simultaneously operated. Thereby, the vibration of the magnetic
circuits 52 and 53 can be suppressed. The specific method is described below.
[0109]
In the speaker device 200, as described above, the winding direction of the voice coil 15 with
respect to the voice coil bobbin 14 and the winding direction of the voice coil 111 with respect to
the voice coil bobbin 110 are respectively reversed. In the speaker device 200, currents (electric
signals) having the same phase and the same magnitude are applied to the voice coils 15 and
111, respectively. Therefore, in the speaker device 200, when currents (electric signals) having
the same phase and the same magnitude are applied to the voice coils 15 and 111 from the
amplifier side, the voice coil bobbins 14 and 110 operate as follows. . When the voice coil bobbin
14 moves in the direction of arrow Y1 with a constant force, the voice coil bobbin 110 moves in
the direction of arrow Y5 with the same force as the constant force. On the other hand, when the
voice coil bobbin 14 moves in the arrow Y2 direction with a constant force, the voice coil bobbin
110 moves in the arrow Y6 direction with the same force as the constant force.
[0110]
01-05-2019
30
Thus, in the magnetic circuits 52 and 53, the force (vibration) generated by the reaction with the
movement of the voice coil bobbin 14 and the force (vibration) generated by the reaction with
the movement of the voice coil bobbin 110 cancel each other. As a result, the generation of
vibration in the magnetic circuits 52 and 53 can be suppressed. As a result, it is possible to
effectively suppress transmission of vibration from the magnetic circuits 52 and 53 through the
frame 17 to the mounting portion 70 such as a cabinet for a vehicle. Therefore, it can suppress
that an unnecessary sound wave (interference sound wave) is emitted from the attachment part
70 in the arrow Y 8 direction shown in FIG. Thereby, the speaker device 200 can reproduce high
quality sound.
[0111]
Further, in the speaker device 200, when the lowest resonance frequency on the main body side
and the lowest resonance frequency on the vibration suppression side are different from each
other, the force (vibration) transmitted to the magnetic circuits 52 and 53 through the voice coil
bobbins 14 and 110. The size of each varies with the frequency. For this reason, also in the
second embodiment, in the speaker device 200, the respective minimum resonance frequencies
of the main body portion and the vibration suppression portion are set to be the same. Thus, in
the speaker device 200, unnecessary sound waves (disturbance from the attachment portion 70
in the direction of the arrow Y 8 shown in FIG. 5) over the entire band of the reproducible
frequency as in the speaker device 100 according to the first embodiment. Sound waves can be
suppressed. As a result, the speaker device 200 can reproduce high quality sound over the entire
band of the reproducible frequency.
[0112]
Further, in the speaker device 200, as in the speaker device 100 according to the first
embodiment, the above-mentioned effect is produced at the frequency 17 or less at which the
frame 17 causes divided vibration (vibration similar to rolling) in order to exert the effects of the
present invention reliably. The vibration suppression method of the magnetic circuits 52 and 53
is set to be effective.
[0113]
[Modifications] In each of the above-described embodiments, the present invention is applied to a
speaker device for reproducing low-pitched sound having a cone-shaped diaphragm, but the
present invention is not limited to this and a dome-shaped diaphragm suitable for high-pitched
sound reproduction The present invention can also be applied to a speaker device that has
01-05-2019
31
[0114]
BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing which shows typically the structure
of the speaker apparatus of 1st Example of this invention.
Sectional drawing which shows typically the structure of the speaker apparatus which concerns
on a comparative example.
The partial top view explaining the effective wire length and winding direction of each voice coil
of a main-body part and a vibration suppression part. The partial top view explaining the
effective wire length and winding direction of each voice coil of the main-body part which
concerns on a modification, and a vibration suppression part. Sectional drawing which shows
typically the structure of the speaker apparatus of 2nd Example of this invention.
Explanation of sign
[0115]
1, 21 pole piece 2, 22 magnet 3, 23 plate 4, 10, 14, 110 voice coil bobbin 5, 11, 15, 111 voice
coil 6, 12, 16, 112 damper 7, 17 frame 8, 18 diaphragm 9, Reference Signs List 19 dustproof cap
13, 113 dummy weight 50, 51, 52, 53, 55 magnetic circuit 60, 61, 62, 63 vibration system 70
attachment portion 100, 200, 500 speaker device
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