close

Вход

Забыли?

вход по аккаунту

JPH01274600

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JPH01274600
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a
loudspeaker, in particular an inductive loudspeaker. SUMMARY OF THE INVENTION A
loudspeaker according to the present invention comprises a diaphragm having an annular
conductive portion, a feed coil disposed to face the R-shaped portion with a predetermined gap,
and a magnetic circuit to which the feed coil is attached. A damper mounted on the magnetic
circuit and vibratably supporting the diaphragm is integrally formed with the conductive portion.
Therefore, the heat can be dissipated efficiently from the damper. And attachment and removal
of a diaphragm become very easy. [Prior Art] In a conventional speaker, particularly an inductive
speaker, a driving force is obtained by supplying an audio signal current to a voice coil in a direct
current magnetic field. The voice signal current is normally supplied to the voice coil from the
outside by a lead wire fixed to a cone paper as a diaphragm. SUMMARY OF THE INVENTION As
described above, in the conventional inductive speaker, the voice signal current is externally
supplied to the voice coil by the lead wire in order to obtain the driving force. However, in the
conventional induction type speaker provided with such a lead wire, there is a disadvantage that
the lead wire is easily cut by the reciprocating motion of the diaphragm. On the other hand, even
when the lead wire is not cut, distortion of the sound is likely to occur because the linearity in
reciprocating motion of the diaphragm is disturbed, and the lead wire itself resonates to generate
abnormal noise. there were. Furthermore, there is a disadvantage that the assembly is
troublesome because the lead wire must be drawn out from the narrow gap of the speaker for
positioning, bonding and fixing during manufacture. Therefore, in order to eliminate the various
defects described above, Japanese Patent Publication No. 56-27039 discloses an induction type
speaker in which the lead wire is removed. In the induction type speaker disclosed in the above
publication, the drive coil is disposed in the vicinity of the voice coil wound around the voice coil
bobbin while removing the lead wire. Then, an audio signal current is supplied to the drive coil,
05-05-2019
1
and an audio signal is supplied from the drive coil to the voice coil by magnetic induction. That is,
when an AC signal from the power amplifier of the audio frequency flows to the drive coil, an AC
magnetic flux corresponding to the input waveform is generated from the drive coil by the AC
signal. Interlock. On the other hand, since the voice coil is short-circuited by itself, a short-circuit
current flows in the voice coil by the above-mentioned alternating current magnetic flux.
Because the voice coil is located in the magnetic field created by the pole piece and the ambient
magnetic scratch, the voice coil exerts a force proportional to the product of the strength of the
magnetic field and the short circuit current. This force causes the cone integrally formed with the
voice coil bobbin to vibrate from the voice coil through the voice coil bobbin, and the sound is
emitted from the cone like a normal speaker. In the technique disclosed in the above-mentioned
publication, although the various defects caused by the lead wire are eliminated because the lead
wire is removed, the following problems are separately caused. . Since the voice coil is generally
fixed to the voice coil bobbin with an adhesive, there is a disadvantage that the driving force
generated in the voice coil is difficult to be directly transmitted to the cone. Also, although the
voice coil necessarily generates heat due to the short circuit current, it has a disadvantage that it
is difficult to dissipate the heat well. Generally, in order to improve the sensitivity of the speaker,
it is required to narrow the gap (magnetic gap) between the coil bobbin and the drive coil and to
wind the voice coil many times in this gap. Ru. Therefore, the diameter of the metal wire used for
the voice coil necessarily becomes smaller, and the heat capacity of the above-mentioned metal
wire becomes smaller. As a result, coupled with the problem of heat dissipation as described
above, the voice coil is easily disconnected due to heat generation, which results in the
disadvantage that the current capacity is limited. Furthermore, there is a disadvantage that the
paper voice coil bobbin is carbonized due to the repeated heat generation described above.
Therefore, an induction type speaker has been proposed in Japanese Utility Model Application
Laid-Open No. 50-105438, in which the above-mentioned lead wire as well as the voice coil has
been removed. That is, in the magnetic gap portion in the magnetic circuit, a diaphragm having
an annular conductive portion is vibratably supported by a damper, and a feed coil electrically
coupled to the conductive portion by mutual induction is disposed oppositely. It is set up. In this
speaker, the voice coil is removed by generating an induction current based on mutual induction
in an annular conductive portion formed in a part of the diaphragm. In the technique disclosed in
the above-mentioned publication, since the voice coil as well as the lead wire is removed, various
defects caused by the lead wire, the voice coil and the like are eliminated. However, since the
damper that supports the diaphragm is generally solidified and formed by impregnating a cloth
material with phenol, it can not dissipate heat generated by the conductive part. There was a
problem.
In addition, since the materials of the diaphragm and the damper are completely different, they
can not be integrally formed, and attachment and detachment of the damper must be performed
05-05-2019
2
each time the diaphragm is attached and detached. Therefore, there is a problem that the
workability is bad and it takes a very long time at the time of manufacture and repair. Therefore,
an object of the present invention is to provide a speaker in which the damper and the
conductive portion are integrally formed. [Means for Solving the Problems] In the speaker
according to the present invention, a diaphragm having an annular conductive portion, a feed
coil disposed to face the conductive portion with a predetermined gap, and a feed coil are
attached. A damper provided with a magnetic circuit and attached to the magnetic circuit to
vibratably support the diaphragm is integrally formed with the conductive portion. [Operation]
When an alternating current as a voice signal is supplied to the feeding coil, an alternating
magnetic flux is generated, and an induction current of the same frequency is induced in the
annular conductive portion based on the linkage flux due to this. . The induced current of the
conductive portion acts on the DC magnetic field at the position of the magnetic gap to excite the
diaphragm to emit a sound wave. At this time, since an induced current flows in the conductive
part, heat is generated by the resistance component of the conductive part. However, this heat is
conducted from the conductive portion to the damper, and is efficiently dissipated by the
damper. In addition, since the conductive portion and the damper are integrally formed, it is not
necessary to attach and detach the diaphragm, and the workability is greatly improved. An
embodiment of the present invention will be described below with reference to the drawings.
This embodiment is an application of the present invention to a dome-shaped speaker as shown
in FIG. 1 to FIG. The description will be made in the following order. (A) First Embodiment (B)
Second Embodiment (C) Modification (A) First Embodiment FIGS. 1 and 2 show the first
embodiment according to the present invention. It is done. In the configuration shown in FIG. 1,
the speaker 1 is mainly composed of a diaphragm 2, a primary feeding coil 3, a plate 4, a magnet
5, and a yoke plate 6. The dome-shaped diaphragm 2 has an annular conductive portion 8 at the
opening edge 7 and a damper 9 integrally formed on the i-type portion 8. The diaphragm 2 is
made of a thin plate-like good conductor such as aluminum, beryllium, magnesium or the like.
The diaphragm 2 is vibratably supported by the damper 9 in a state where the conductive
portion 8 is positioned in the magnetic gap portion 10. The damper 9 has a spring property, is
annularly formed around the conductive portion 8, and is fixed on the plate 4.
The above-mentioned magnetic gap 10 is annularly formed between the plate 4 and the pole
piece 11 of the yoke plate 6. The primary feeding coil 3 electrically couples the annular
conductive portions 8 by mutual induction action, and is disposed opposite to the conductive
portions 8 with a predetermined gap. The primary feed coil 3 is disposed opposite to the outer
periphery corresponding position or the inner periphery corresponding position of the
conductive portion 8 The primary feed coil 3 in the example shown in the figure corresponds to
the outer periphery of the annular conductive portion 8 It is fixed to one side end face 12 of the
plate 4 in order to make it work. When the primary feeding coil 3 is provided at a position
corresponding to the inner circumference of the conductive portion 8, the primary feeding coil 3
is fixed to the outer circumference 13 of the pole piece 11. The primary feeding coil 3 may be
05-05-2019
3
provided at both the outer periphery corresponding position or the inner periphery
corresponding position of the conductive portion 8. The plate 4, the magnet 5, the yoke plate 6,
and the pole piece 11 constitute a magnetic circuit. That is, as shown in FIG. 1, the magnet 5 is
fixed to the outer peripheral portion on the yoke plate 6, and the plate 4 is fixed to the outer
peripheral portion on the magnet 5. A magnetic circuit is formed with the magnetic gap lO
separated by a path from the magnet 5 to the plate 4 and from the magnet 5 to the yoke plate 6
and the pole piece 11 of the yoke plate 6. Next, an example of the state in which the diaphragm 2
is formed will be described with reference to FIG. First, the opening edge 15 of the cylindrical
body 14 as shown in FIG. 2A is folded to form an annular peripheral edge 16 as shown in FIG.
2B. Next, a damper 9 having a spring property is annularly formed at the peripheral portion 16
described above. At this time, an annular fixing portion 17 to the plate 4 is also formed. Thus, the
diaphragm 2 is formed. The means for forming the diaphragm 2 can be selected appropriately as
a press or the like. Next, the operation of the speaker 1 will be described. When an alternating
current as a voice signal is supplied to the primary feeding coil 3, an alternating magnetic flux
corresponding to a human power waveform is generated. Due to the flux linkage, an inductive
current of the same frequency is induced in the annular conductive portion 8 by the mutual
induction phenomenon. このN1. Since the portion 8 is located in the magnetic gap 10, a force
proportional to the product of the strength of the direct current magnetic field in the magnetic
gap lO and the induced current acts on the conductive portion 8, ie, The induction current of the
portion 8 acts on the DC magnetic field in the magnetic gap 10 to drive the diaphragm directly to
emit an acoustic wave.
At this time, since an induced current flows in the conductive portion 8, heat is generated by the
resistance component of the conductive portion 8. However, this heat is transmitted from the
conductive portion 8 to the damper 9 and dissipated by the damper 9. By the way, in the high
frequency part of the audio signal, the reciprocating motion of the diaphragm 2 is relatively
small (but, since the damper 9 has a spring property, it can sufficiently follow the reciprocating
motion of the diaphragm 2. Further, since the diaphragm 2 is also integrally formed with the
damper 9, it is easy to attach to and detach from the plate 4. In this speaker 1, the diaphragm 2
as the vibration system and the primary feeding coil 3 on the fixed side are mechanically
separated and electrically coupled by mutual induction, so that the conventional voice can be
obtained. It can operate in the state which does not arrange a coil, a voice coil bobbin, a lead
wire, etc. Therefore, since the conductive portion 8 as a driving force generation source can be
integrally formed with the diaphragm 2, it is possible to solve all the problems associated with
the connection thereof. That is, cutting of the lead wire, generation of abnormal noise due to lead
resonance, inhibition of linearity due to the lead wire, generation of sound distortion due to it,
indirect transmission of driving force by the adhesive of the voice coil, voice coil Problems such
as disconnection due to heat and carbonization of the voice coil bobbin are eliminated. As a
result, excellent vibration characteristics and sound quality can be obtained, and a wide degree of
freedom can be provided to the acoustic characteristics. (B) Second Embodiment The second
05-05-2019
4
embodiment differs from the first embodiment in the method of forming the diaphragm 20. An
example of the formation of the diaphragm 20 in the second embodiment is shown in FIG. A
hemispherical body 21 is shown in FIG. 3A, and an annular plate 22 is shown in FIGS. 3B and 3C,
respectively. First, as shown in FIGS. 3D and 3E, an annular conductive portion 23, a damper 24
and a fixing portion 25 are formed on the plate 22, respectively. Next, as shown in FIG. 3F, the
diaphragm 20 is formed by connecting the hemispherical body 21 and the plate 22. The other
configurations and operations are the same as those of the first embodiment, and the redundant
description will be omitted. (C) Modification A modification is shown in FIG. This is to prevent the
induction current induced in the conductive portion 8 from flowing to the damper 9, and as
shown in FIG. 4, the notch 31 is formed in the connecting portion 30 to the diaphragm 2 of the
damper 9 It is annularly formed. The incision 31 reduces the area which can be conducted, and
the resistance value is relatively increased. As a result, the flow of the induced current into the
damper 9 is prevented, and the efficiency of the current can be enhanced.
In the first and second embodiments and the modification, although the dome-shaped speaker is
described as an example, the present invention is not limited to this and, of course, can be
applied to a cone-shaped speaker. is there. Further, although the illustrated example is an
external magnet type in which the magnet 5 is disposed on the outer periphery, it is of course
possible to apply the same to an internal magnetic type in which the magnet 5 is disposed on the
pole piece 11. According to the present invention, since the damper attached to the magnetic
circuit and supporting the diaphragm in a vibrating manner is integrally formed with the
conductive portion, the heat generated in the conductive portion is dissipated more efficiently
than the damper. It has the effect of being able to As a result, the current capacity in the
conductive portion of the diaphragm is increased, and there is an effect that a large induced
current can be flowed to the conductive portion. And there is an effect that attachment and
removal of a diaphragm can be made extremely easy. This has the effect that the workability at
the time of manufacture and repair can be greatly improved. In addition, since the conventional
voice coil, voice coil bobbin, lead wire, etc. are not disposed, cutting of the lead wire, generation
of abnormal noise due to resonance of the lead wire, inhibition of linearity due to the lead wire
and distortion of sound due to it There is an effect that the problems such as the generation of
noise, the indirect transmission of the driving force by the adhesive of the voice coil, the
disconnection due to the heat of the voice coil and the carbonization of the voice coil bobbin are
eliminated. Further, since the damper has a spring property, it has an effect that the followability
to the reciprocating motion of the diaphragm is improved particularly in the high region.
[0002]
Brief description of the drawings
05-05-2019
5
[0003]
FIG. 1 is a sectional view showing a first embodiment of the present invention, FIG. 2 is an
explanatory sectional view showing a method of forming the diaphragm shown in FIG. 1, and FIG.
3 is a second embodiment. Sectional drawing equivalent to 2 figures, FIG. 4 is the elements on
larger scale of the modification of the modification of this invention.
Explanation of main symbols in the drawings 1: Speaker 2, 20: Diaphragm, 3: 1 Primary feeding
coil, 4 nibrates, 5: Magnet, 6: Yoke plate, 8.23: Conductive part, 9.24: Damper, ll: Pole piece.
Agent Attorney Sugiura Masatoshi, v / 1 Skier sectional view Fig. 1 Man 4 Fig. 2 Fig. 2 (i surface
Megumi Akira) (LtIt surface explanatory drawing) Fig. 3
05-05-2019
6
1/--страниц
Пожаловаться на содержимое документа