JP2003244790

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DESCRIPTION JP2003244790
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a
speaker used for various audiovisual devices.
[0002]
2. Description of the Related Art The prior art will be described with reference to the side
sectional view of the speaker shown in FIG.
[0003]
In the figure, 1 is a magnet, 2 is an upper yoke provided on the upper surface of the magnet 1, 3
is a lower yoke provided on the lower surface of the magnet 1, 4 is a center pole continuous with
the lower yoke 3, 5 is an upper A magnetic gap between the inner peripheral surface of the yoke
2 and the outer peripheral surface of the center pole 4, a frame 6 adhesively bonded to the upper
surface of the upper yoke 2, and a voice coil 7 having a coil portion disposed in the magnetic gap
5. A damper 8 has an inner periphery fixed to the voice coil 7 and an outer periphery fixed to the
frame 6. A diaphragm 9 has an inner periphery fixed to the voice coil 7 and an outer periphery
fixed to the frame 6 through an edge 10 to be described later. Is an edge where the inner
periphery is fixed to the diaphragm 9 and the outer periphery is fixed to the frame 6 (a magnetic
circuit is formed by the magnet 1, the upper yoke 2 and the lower yoke 3 having the center pole
4).
[0004]
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The operation of the loudspeaker configured as described above will be described below.
When current flows in the coil portion wound around the voice coil 7, the current is orthogonal
to the magnetic field in the magnetic gap 5, and according to Fleming's law, a force is generated
in a direction perpendicular to each of the magnetic field and the current.
At this time, the damper 8 and the edge 10 support the voice coil 7 so as to be concentric with
the center pole 4, and when the diaphragm 9 vibrates, the middle point in the thickness direction
of the upper yoke 2 and the coil winding width of the voice coil 7 It acts as a spring in the
direction of amplitude in which a force is applied to make the points coincide, and the voice coil
7 and the diaphragm 9 oscillate while being supported by the damper 8 and the edge 10. As a
result, air is vibrated to generate compression waves, which are heard as sounds.
[0005]
However, in the above-described speaker configuration, the asymmetry of the supporting force of
the damper 8 and the edge 10 and the asymmetry of the back pressure applied to the diaphragm
9 when the speaker is attached to the speaker box and reproduced Depending on the nature, the
vibration system may not perform the ideal piston movement and may cause a rolling
phenomenon.
[0006]
FIG. 10 is a diagram showing the movement of the diaphragm 9 and the voice coil 7 during
rolling by arrows, but as shown in the figure, when this phenomenon occurs, the voice coil 7
contacts the yokes 2 and 3 and abnormal noise In order to prevent the occurrence of damage or
breakage, the magnetic gap 5 is widely provided in advance.
[0007]
The smaller the magnetic gap 5, the greater the magnetic flux density obtained and the higher
the efficiency, but the wider the efficiency, the lower the efficiency.
[0008]
Furthermore, when a rolling phenomenon occurs at a specific frequency, as shown in FIG. 10, the
entire diaphragm 9 does not move in phase but moves partially in reverse phase, so that the
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sound pressure frequency characteristic is disturbed. Occur.
[0009]
Further, as shown in the force-displacement characteristic of the damper 8 (FIG. 11), the
relationship between the force and the displacement of the damper 8 is not linear, and further
has a hysteresis, so that harmonic distortion occurs in the sound pressure frequency
characteristic. .
[0010]
An object of the present invention is to provide an excellent speaker which solves the abovementioned subject.
[0011]
SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a speaker
according to claim 1 of the present invention comprises a magnetic circuit having at least a
center pole, and a frame coupled to the magnetic circuit. A speaker comprising: a diaphragm
having an outer periphery coupled to the frame via an edge; and a voice coil integrated on an
inner periphery of the diaphragm, the speaker being provided vertically projecting from the
center pole And an elastic disk provided on the inner periphery of the voice coil mounted on the
shaft, and the elastic disk restricts the swaying of the voice coil at the time of vertical movement,
thereby rolling the diaphragm. The noise is suppressed to prevent the generation of abnormal
noise and the damage of the voice coil.
[0012]
According to a second aspect of the present invention, the shaft and the disk according to the
first aspect are integrally formed, and can contribute to reduction of the number of parts and
improvement of the workability.
[0013]
According to the third aspect of the present invention, the disk according to the first aspect is
supported by the shaft so as to move up and down, and the disk and the voice coil are integrally
formed. It can contribute to the improvement of
[0014]
According to a fourth aspect of the speaker of the present invention, the shaft according to the
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first aspect is supported on the center pole so as to be vertically movable, and the shaft, the disk,
and the voice coil are integrally formed. Can contribute to the reduction of
[0015]
According to the fifth aspect of the speaker of the present invention, the disk according to the
first aspect is supported on the shaft so as to be vertically movable, and the shaft is integrally
formed with the center pole, thereby reducing the number of parts. Can contribute to the
improvement of work efficiency.
[0016]
According to a sixth aspect of the speaker of the present invention, the projection is provided on
the outer circumference of the disk according to the first aspect, the second aspect or the fifth
aspect, and the outer circumference of the disk in sliding contact with the inner circumference of
the voice coil. By providing a projection on the surface, the possibility of an obstacle is further
reduced as a smooth sliding contact as a guide of the voice coil.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a loudspeaker according
to the present invention will be described below with reference to FIGS. 1 to 8. FIG.
[0018]
In the description, the same parts as in the prior art will be assigned the same reference
numerals and explanations thereof will be omitted.
[0019]
(First Embodiment) FIG. 1 is a side sectional view of an embodiment of a speaker according to the
present invention, FIG. 2 (a) is a side sectional view of a disk which is the same main part, and
FIG. FIG. 3 is a top view, FIG. 3 is a sound pressure frequency characteristic and a third harmonic
distortion characteristic view, and FIG. 4 (a) is a side cross sectional view of an axis and a disc
which are main parts of the other development example. 4 (b) is a top view of the same, FIG. 5 (a)
is a side sectional view of a voice coil and a disk which are the main parts of the other developed
example, and FIG. 5 (b) is a top view. 6 (a) is a side sectional view of a voice coil, a disk, and a
shaft which are the main parts of the other developed example, FIG. 6 (b) is a top view thereof,
and FIG. FIG. 8 is a side sectional view of a shaft and a center pole which are main parts of an
example, and FIG. 8 is a side sectional view of a shaft, a center pole and a disk which are main
parts of the other development example.
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[0020]
The difference from the prior art will be described with reference to FIG. 1. 11 is an axis fixed on
the center pole 4 and 12 is a disk fixed on the axis and guiding the inner periphery of the voice
coil 7 It is formed by the metal plate which has, or resin which becomes flexible and becomes an
elastic body.
[0021]
Incidentally, as shown in FIG. 2, the disk 12 is constituted by an annular portion 12a, an inner
periphery 12b bonded and adhered to the shaft 11, an arm portion 12c overlying the outer
periphery 12a and the inner periphery 12b and having elasticity as a shape. It has a shape.
[0022]
The configuration in which the inner periphery of the voice coil 7 is guided by the disk 12
suppresses the sway of the voice coil 7 due to the rolling phenomenon of the diaphragm 9 to
prevent the generation and damage of abnormal noise due to the sway of the voice coil 7 during
the vertical movement. At the same time, by making the disk 12 an elastic body, the vibration of
the voice coil 7 is suppressed while being suppressed, and the disk 12 itself prevents generation
of abnormal noise due to a collision with the voice coil 7 etc. The air gap 5 can be narrowed, the
efficiency can be improved, and by eliminating the conventional damper, the acoustic
characteristics due to the damper can also be improved.
[0023]
FIG. 3A shows the sound pressure frequency characteristics of the speaker according to the
present embodiment, and the improvement of the sound pressure is confirmed as compared with
that of the conventional one (B), and the third harmonic of the speaker according to the present
embodiment The wave distortion C was also confirmed to be lower than that of the conventional
one (D).
[0024]
FIGS. 4A to 9 show the main parts of a developed example of the present embodiment, and
according to FIG. 4, 13 is a disk formed by integral resin molding of a disk 12a and a shaft 11a,
which reduces the number of parts. In addition, it is intended to improve the ease of
incorporation into the speaker and the speaker.
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[0025]
Further, in the developed example of FIG. 5, the disc 13 b and the voice coil 7 a are integrally
resin-molded to form the disc 14, and similar to the developed example of FIG. It is intended to
improve the quality.
[0026]
Further, in the developed example of FIG. 6, the disk 13c, the voice coil 7b, and the shaft 11b are
integrally resin-molded to constitute the disk 15, thereby further reducing the number of parts
and improving the workability of incorporation into the speaker. It is a thing.
[0027]
Further, in the developed example of FIG. 7, the lower yoke 16 is formed by simultaneously
molding the shaft 11c and the center pole 4a of the lower yoke portion 3a with magnetic metal,
and although the object is different, the number of parts is the same as the developed example
described above. To improve the ease of installation and integration into the speaker.
[0028]
Further, FIG. 8 simultaneously forms the lower yoke 17 by molding the magnetic metal
simultaneously with the shaft 11d and the center pole 4b of the lower yoke portion 3b, and also
forms a disk 13e in which a plurality of arc-shaped projections 13d are integrally formed on the
outer periphery simultaneously. It forms, and while aiming at the reduction of the number of
parts and the improvement of the workability of incorporation in a speaker, contact and sliding
contact with inner circle of voice coil 7 and disk 13e can be smoothly performed by a plurality of
projections 13d. It is.
[0029]
The shape of the disk 13e can be applied to the disk and the disk of the present embodiment, and
the same effect as the voice coil 7 can be obtained.
[0030]
As described above, according to the present embodiment, by performing the support of the
voice coil without using the damper, as described above, the efficiency can be improved and the
sound pressure frequency characteristic can be improved and the distortion can be reduced.
[0031]
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Although the external magnetic type is used as the magnetic circuit in the present embodiment,
in the case of a speaker type using a voice coil and a diaphragm, application to a speaker of an
internal magnetic type or another type of known magnetic circuit Is also possible.
[0032]
As described above, the speaker according to the present invention suppresses the vibration of
the voice coil at the time of vertical movement and controls the rolling of the diaphragm to
improve the sound pressure of the sound pressure frequency characteristic and reduce the
distortion. Enables provision of a speaker.
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