close

Вход

Забыли?

вход по аккаунту

?

JP2006020139

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 JP2006020139
PROBLEM TO BE SOLVED: To provide a speaker requiring a high output sound pressure and a
speaker magnetic circuit used therefor, which is an inexpensive external magnet type magnetic
circuit, which keeps the magnetic flux density distribution of magnetic gaps high in a wide range,
Increase the density enough. SOLUTION: The magnetic circuit for a speaker according to the
present invention comprises a plate, a main magnet whose upper surface is fixed to the lower
surface of the plate, a yoke whose flat plate is fixed to the lower surface of the main magnet, and
a pole of the yoke. A first sub magnet whose lower surface is fixed to the upper surface; a pole
piece whose lower surface is fixed to the upper surface of the first sub magnet; and a second sub
magnet whose lower surface is fixed to the upper surface of the pole piece The main magnet and
the first sub magnet and the second sub magnet, which are respectively magnetized, have the
same polarity on the lower surface side of the main magnet, the upper surface side of the first
sub magnet, and the lower surface side of the second sub magnet. [Selected figure] Figure 1
Speaker magnetic circuit and speaker
[0001]
The present invention relates to a speaker magnetic circuit, and more particularly to a speaker
requiring a high output sound pressure and a speaker magnetic circuit used therein.
[0002]
FIG. 4 (a) is a plan view for explaining the conventional speaker magnetic circuit 1, and FIG. 4 (b)
is a sectional view taken along the line A-A '.
13-05-2019
1
The speaker magnetic circuit 1 includes a plate 2, a pole piece 3 and a main magnet 4, and an
inner diameter side surface of the plate 2 and an outer diameter side surface of a pole portion of
the pole piece 3 define a magnetic gap 5. The main magnet 4 has a top surface fixed to the
bottom surface of the plate 2 and a bottom surface fixed to the flat plate of the pole piece 3.
Typically, the main magnet 4 is a ferrite magnet having ferromagnetism. The gap 5 is located
outside the area defined by the gap 5. This speaker magnetic circuit 1 is generally referred to as
an external magnet type magnetic circuit, and is inexpensive for the performance obtained, and
thus is used in many speakers.
[0003]
In the case of a speaker requiring high output sound pressure, it is necessary to increase the
magnetic flux density B of the magnetic gap 5, and in the case of an external magnet type
magnetic circuit, the main magnet 4 is enlarged and so on. It copes by increasing the magnetic
force. FIG. 2 is a graph showing the distribution of the magnetic flux density B at the magnetic air
gap 5 of the speaker magnetic circuit 1. For example, curve (b) represents an example of a
conventional external magnet type magnetic circuit of a speaker of 8 cm diameter, which is about
0.98 Tesla at the highest magnetic flux density. For example, in order to increase the magnetic
flux density B to 1.0 Tesla or more in the external magnet type magnetic circuit, the main magnet
4 becomes considerably large, and thus the weight of the magnetic circuit and the entire speaker
becomes heavy.
[0004]
FIG. 5 is a cross-sectional view for explaining another conventional speaker magnetic circuit 1. 5
(a) is a plan view, and FIG. 5 (b) is an A-A 'sectional view. The speaker magnetic circuit 1 is an
internal magnetic type magnetic circuit in which the magnet is positioned inside the area defined
by the magnetic gap 5 in plan view, and the magnets 6 and 8 of the same polarity sandwiching
the top plate 7. It is a repulsive type magnetic circuit which makes In the internal magnetic type
magnetic circuit and the repulsive type magnetic circuit, the weight of the entire magnetic circuit
and the speaker can be reduced, but in order to sufficiently increase the magnetic flux density B
of the magnetic gap 5, an expensive magnet such as a neodymium magnet is used. In order to
secure the magnetomotive force, it must be used in a large size, which is disadvantageous in cost.
13-05-2019
2
[0005]
Conventionally, in order to increase the magnetic flux density of the magnetic gap of the
inexpensive external magnetic type magnetic circuit, a fixed magnet is newly provided on the
upper surface of the center pole of the external magnetic type magnetic circuit, and the magnetic
pole on the center pole side of the fixed magnet is There is one in which the same pole surface as
the magnetic pole generated on the center pole of the external magnetic type magnetic circuit is
obtained (Japanese Patent Application Laid-Open No. 2001-147118).
[0006]
Patent Document 1: Japanese Patent Application Laid-Open No. 10-112896 (FIGS. 1 to 4)
[0007]
However, in the speaker external magnetic type magnetic circuit of the prior art, when a
particularly high output sound pressure is required for a small speaker, the magnetic flux density
of the magnetic gap may not be able to be increased sufficiently and sufficiently.
When a fixed magnet is newly provided on the top surface of the center pole of the external
magnetic type magnetic circuit (FIG. 4 of Patent Document 1), the magnetic flux density
distribution (curve a) of the magnetic gap in the range where the voice coil is located is The
range above and below the curve b) may coexist, and as a result, there is a problem that the
average magnetic flux density can not be increased sufficiently.
[0008]
The present invention has been made to solve the above-mentioned problems of the prior art,
and the object thereof relates to a magnetic circuit for a speaker, and more particularly to a
speaker requiring high output sound pressure and a magnetic for the speaker used therein. The
present invention relates to a circuit, which is an inexpensive external magnet type magnetic
circuit, and is to provide a speaker magnetic circuit which can keep the magnetic flux density
distribution of the magnetic gap high in a wide range and increase the average magnetic flux
density as necessary.
[0009]
The speaker magnetic circuit according to the present invention is a speaker magnetic circuit in
13-05-2019
3
which the inner diameter side of the plate and the pole piece outer diameter side define a
magnetic gap, and the main magnet has an upper surface fixed to the plate and the lower surface
of the plate. A yoke having a flat plate fixed to the lower surface of the main magnet, a first sub
magnet having the lower surface fixed to the upper surface of the pole of the yoke, and a lower
surface having the upper surface fixed to the first sub magnet A pole piece and a second sub
magnet whose lower surface is fixed to the upper surface of the pole piece, and the polarities of
the magnetized main magnet, first sub magnet and second sub magnet are respectively on the
lower surface side of the main magnet The same polarity is applied to the upper surface side of
the first sub magnet and the lower surface side of the second sub magnet.
[0010]
Furthermore, in the speaker magnetic circuit of the present invention, when the speaker
magnetic circuit is viewed in plan, the main magnet is located outside the region defined by the
magnetic gap, and the first sub magnet and the second sub magnet are in the magnetic gap.
Located inside the defined area.
[0011]
Still preferably, in a speaker magnetic circuit according to the present invention, the main
magnet is a ferrite magnet, and the first sub magnet and the second sub magnet are neodymium
magnets.
[0012]
Furthermore, preferably, the speaker magnetic circuit of the present invention further includes a
connecting and fixing member, and the connecting and fixing member connects and fixes the
pole upper surface of the yoke and the pole piece.
[0013]
Furthermore, the speaker of the present invention includes the speaker magnetic circuit of any of
the above-described present invention, a voice coil disposed in the magnetic gap of the magnetic
circuit, and a diaphragm to which the voice coil is coupled.
[0014]
Hereinafter, the operation of the present invention will be described.
[0015]
13-05-2019
4
In the speaker magnetic circuit of the present invention, the plate inner diameter side surface
and the pole piece outer diameter side surface define a magnetic air gap.
In addition, the polarities of the magnetized main magnet, the first sub magnet and the second
sub magnet fixed to the plate and the pole piece respectively are the lower surface side of the
main magnet, the upper surface side of the first sub magnet and the second sub magnet On the
lower side of the same polarity.
Therefore, in the speaker magnetic circuit of the present invention, the magnetic flux density
distribution of the magnetic gap is obtained by combining the magnetic flux due to the
magnetomotive force of the main magnet and the magnetic flux repelled by the magnetomotive
force of the first sub magnet and the second sub magnet. It can be kept high and the average
magnetic flux density can be increased sufficiently.
As a result, the magnetic flux density of the magnetic gap can be increased compared to the
conventional speaker magnetic circuit.
In a preferred embodiment, the speaker of the present invention further comprises a voice coil
disposed in the magnetic gap of the magnetic circuit, and a diaphragm to which the voice coil is
coupled, using the magnetic circuit for a speaker of the present invention Thus, a speaker
capable of reproduction at high output sound pressure is provided.
[0016]
In a preferred embodiment, in the speaker magnetic circuit of the present invention, when the
speaker magnetic circuit is viewed in plan, the main magnet is located outside the area defined
by the magnetic gap, and the first sub magnet and the second sub magnet Are located inside the
defined area of the magnetic gap.
The main magnet constitutes a so-called external magnet type magnetic circuit, and the first sub
magnet, the pole piece and the second sub magnet constitute a so-called repulsive type magnetic
circuit, and as a result, compared to the conventional magnetic circuit for a speaker The magnetic
13-05-2019
5
flux density can be increased.
In the speaker magnetic circuit of the present invention, the magnetic flux from the external
magnet type magnetic circuit and the magnetic flux from the repulsive type magnetic circuit do
not cancel each other in the range of the magnetic gap, so the upper surface of the center pole of
the conventional external magnet type magnetic circuit. The magnetic flux distribution in the
magnetic gap is improved symmetrically in the vertical direction as compared with the case
where a fixed magnet is newly provided.
Therefore, the speaker magnetic circuit of the present invention can keep the magnetic flux
density distribution of the magnetic gap high in a wide range, and can increase the average
magnetic flux density as necessary.
[0017]
In a preferred embodiment, in the speaker magnetic circuit of the present invention, the main
magnet is a ferrite magnet, and the first sub magnet and the second sub magnet are neodymium
magnets.
Therefore, since an inexpensive ferrite magnet can be used as a main magnet and a neodymium
magnet having high cost but strong magnetomotive force can be used as a first sub magnet and a
second sub magnet with a small volume, the magnetic flux density distribution of the magnetic
gap is kept high. On the other hand, the cost of the entire speaker magnetic circuit can be
reduced.
[0018]
In a further preferred embodiment, the speaker magnetic circuit of the present invention further
comprises a connecting and fixing member, and the connecting and fixing member connects and
fixes the pole top surface of the yoke and the pole piece. The connection fixing member is, for
example, a screw, and is connected to a screw hole provided on the upper surface of the pole
portion of the yoke through a through hole provided in the pole piece. In the process of
completing the speaker magnetic circuit of the present invention, the external magnet type
magnetic circuit consisting of the main magnet and the repulsion type magnetic circuit consisting
13-05-2019
6
of the first sub magnet, the pole piece and the second sub magnet are respectively magnetized
These may be connected by the connecting and fixing member. Therefore, it is possible to easily
obtain a speaker magnetic circuit that can keep the magnetic flux density distribution of the
magnetic gap of the present invention high in a wide range.
[0019]
The speaker magnetic circuit and the speaker according to the present invention are inexpensive
external magnetic type magnetic circuits, particularly in the speaker requiring high output sound
pressure and the speaker magnetic circuit used therefor, and the magnetic flux density
distribution of the magnetic gap It is possible to provide a speaker magnetic circuit that can be
kept high in a wide range and can increase the average magnetic flux density as necessary.
[0020]
The magnetic circuit for a speaker according to the present invention is an inexpensive external
magnet type magnetic circuit, which keeps the magnetic flux density distribution of the magnetic
gap high in a wide range and increases the average magnetic flux density as needed. This is
realized by combining the magnetic flux due to the magnetic flux and the magnetic flux repelled
by the magnetomotive force of the first sub magnet and the second sub magnet.
[0021]
Hereinafter, a speaker magnetic circuit and a speaker according to preferred embodiments of the
present invention will be described, but the present invention is not limited to these
embodiments.
[0022]
FIG. 1 is a view for explaining a speaker magnetic circuit 1 according to a preferred embodiment
of the present invention.
1 (a) is a plan view, and FIG. 1 (b) is an A-A 'sectional view.
The speaker magnetic circuit 1 includes a plate 2, a yoke 3, a pole piece 7, a main magnet 4, a
first sub magnet 6 and a second sub magnet 8.
13-05-2019
7
[0023]
The plate 2, the yoke 3 and the pole piece 7 are typically made of a metal such as iron or a soft
magnetic material such as ferrite.
For example, the plate 2 and the pole piece 7 are disk-shaped metal plates, and the plate 2 is
provided with a through hole, and the inner diameter side surface of the through hole of the
plate 2 and the outer diameter side surface of the pole piece 7 are magnetic for speaker The
magnetic air gap 5 of the circuit 1 is defined. The yoke 3 includes a flat plate portion 3a and a
pole portion 3b protruding from the center of the flat plate portion 3a. Further, the main magnet
4, the first sub magnet 6 and the second sub magnet 8 are ferromagnetic magnets and have a
magnetomotive force and a coercivity in the magnetized state. Here, the main magnet 4 is a
ferrite magnet, and the first sub magnet 6 and the second sub magnet 8 are neodymium
magnets.
[0024]
The lower surface portion of the plate 2 is fixed to the upper surface portion of the main magnet
4, and the lower surface portion of the main magnet 4 is fixed to the flat plate portion 3 a of the
yoke 3. The first sub magnet 6 has its lower surface fixed to the upper surface of the pole 3b of
the yoke 3, the pole piece 7 has its lower surface fixed to the upper surface of the first sub
magnet 6, and the second sub magnet 8 has The lower surface portion is fixed to the upper
surface portion of the pole piece 7. The height of the pole portion 3b of the yoke 3 is such that
the inner diameter side surface of the plate 2 and the outer diameter side surface of the pole
piece 7 face each other. As a result, the magnetic air gap 5 is defined by the inner diameter side
of the plate 2 and the outer diameter side of the pole piece 7. The fixing of each component is
performed by defining the positional relationship between each component using an assembly jig
and fixing each component with an adhesive.
[0025]
Here, when the speaker magnetic circuit 1 is viewed in a plan view, the main magnet 4 is located
outside the region defined by the magnetic gap 5 and constitutes a so-called external magnet
type magnetic circuit. In addition, the first sub magnet 6 and the second sub magnet 8 are
13-05-2019
8
located inside the area defined by the magnetic gap 5 to constitute a so-called repulsive magnetic
circuit. The polarities of the magnetized main magnet 4 and the first sub magnet 6 and the
second sub magnet 8 are on the lower surface side of the main magnet 4, the upper surface side
of the first sub magnet 6 and the lower surface side of the second sub magnet 8. , The same
polarity. Therefore, in the speaker magnetic circuit 1 of the present invention, the magnetic gap
due to the magnetomotive force of the main magnet 4 and the magnetic flux repelled by the
magnetomotive force of the first sub magnet 6 and the second sub magnet 8 are combined to
form the magnetic gap. The magnetic flux density distribution can be kept high, the vertical
symmetry of the magnetic flux density distribution can be improved, and the average magnetic
flux density can be increased sufficiently.
[0026]
In terms of cost, among the components of the speaker magnetic circuit 1, the magnet occupies a
high ratio. The main magnet 4 of the speaker magnetic circuit 1 is an inexpensive ferrite magnet,
and the first sub magnet 6 and the second sub magnet 8 can be neodymium magnets that are
expensive but have a strong magnetomotive force. Therefore, since it is possible to use expensive
neodymium magnets with high magnetomotive force as the first sub magnet 6 and the second
sub magnet 8 with a small volume, the magnetic flux density distribution of the magnetic gap 5
can be kept high while the speaker The cost of the entire magnetic circuit 1 can be reduced.
[0027]
FIG. 2 is a diagram showing the magnetic flux density distribution of the magnetic gap 5 of the
speaker magnetic circuit 1. Curve (a) is an example of the speaker magnetic circuit 1 of the
present invention, and curve (b) is a comparative example of the external magnetic circuit of the
prior art, and the dimensions of major parts such as the magnetic gap 5 Is the same. Here, a
curve (a) showing an example shows a magnetic flux density as high as about 1.40 [T] in a range
t1 corresponding to the thickness dimension of the plate 2 or the thickness dimension of the pole
piece 7 and shows a comparative example It is possible to obtain a higher value than the curve
(b) showing. Furthermore, the curve (a) representing the embodiment does not fall below the
curve (b) representing the comparative example even in the range t2 in which the voice coil is
located. Therefore, in the speaker magnetic circuit 1 of the present invention, as a result, the
average magnetic flux density can be increased as necessary. In the present example and the
comparative example, the magnetic circuit 1 used for a speaker provided with a cone-shaped
diaphragm having an aperture of 8 cm, wherein the thickness dimension t1 of the plate 2 and the
pole piece 7 = 4.0 mm, the voice coil is positioned The range t2 = 6.0 mm.
13-05-2019
9
[0028]
The speaker (not shown) of the present invention including the speaker magnetic circuit 1
further includes a voice coil disposed in the magnetic gap 5 and a diaphragm to which the voice
coil is coupled. The speaker of the present invention can keep the magnetic flux density
distribution of the magnetic gap 5 high, and therefore, by using the speaker magnetic circuit 1,
reproduction with high output sound pressure becomes possible. For example, while the output
sound pressure level of the speaker provided with the cone-shaped diaphragm having an
aperture of 8 cm is 83.1 dB / W / m in the case of the embodiment of FIG. 2 and the comparative
example, the embodiment Then, 84.6 dB / W / m can be realized. At the same time, since the cost
of the speaker magnetic circuit 1 is reduced, the cost of the entire speaker can be reduced even if
the speaker is required to reproduce at high output sound pressure.
[0029]
The speaker magnetic circuit and the speaker according to the present invention are not limited
to the diameter and size of the above embodiment. Even if it is a speaker of other calibers, it
should just be a speaker provided with a magnetic circuit which uses a ferrite magnet as a main
magnet, and is not limited to these embodiments.
[0030]
FIG. 3 is a view for explaining a speaker magnetic circuit 1 according to another preferred
embodiment of the present invention. FIG. 3A is a plan view, and FIG. 3B is a cross-sectional view
taken along the line A-A '. The speaker magnetic circuit 1 includes a plate 2, a yoke 3, a pole
piece 7, a main magnet 4, a first sub magnet 6, a second sub magnet 8, and a connecting and
fixing member 9. For example, the connecting and fixing member is a nonmagnetic screw 9, and
the screw 9 connects and fixes the pole 3 b upper surface of the yoke 3 and the pole piece 7.
Specifically, the first sub-magnet 6, the pole piece 7 and the second sub-magnet 8 have through
holes, and the screw 9 passes through these through holes and a screw hole 3c provided on the
upper surface of the pole portion 3b of the yoke 3 Link.
[0031]
13-05-2019
10
In the process of completing the speaker magnetic circuit 1 of the present invention, the external
magnet type magnetic circuit comprising the main magnet 4 and the repulsion type magnetic
circuit comprising the first sub magnet 6, the pole piece 7 and the second sub magnet 8 are
respectively It is sufficient to magnetize and connect them with a screw 9 which is a connecting
and fixing member. The fixing of the respective components of the external magnet type
magnetic circuit and the repelling type magnetic circuit is performed by fixing the respective
components with an adhesive. Thereafter, the magnetic gap 5 is defined using an assembly jig,
and the external magnetic magnetic circuit and the repulsive magnetic circuit are connected by
the screw 9. It is difficult to define the magnetic circuit 5 by bringing a magnetic force close to
each other because the magnetized external magnetic type magnetic circuit and the repulsion
type magnetic circuit mutually act, but by connecting with the screw 9, an adhesive As compared
with fixing only by itself, the assembly jig can be removed before the adhesive completely
solidifies. Then, the number of speaker magnetic circuits 1 that can be manufactured per unit
time can be increased, and as a result, the manufacturing cost of the speaker magnetic circuit 1
can be reduced.
[0032]
Although the connecting and fixing member 9 is a nonmagnetic screw 9 in this embodiment, the
present invention is not limited to this. Any means may be used as long as the magnetic force
acting on the magnetized external magnetic circuit and the repulsive magnetic circuit can be
connected with a larger force before the adhesive is completely solidified. For example, the
connecting and fixing member 9 may be a projection provided on the upper surface of the pole
portion 3b of the yoke 3. By caulking this projection, the external magnet type magnetic circuit
and the repulsive type magnetic circuit are connected. It is also good. By connecting by the
connecting and fixing member 9, as compared with the case of fixing only by the adhesive, if the
assembly jig can be removed before the adhesive is completely solidified, the manufacturing cost
can be reduced.
[0033]
The speaker magnetic circuit and the speaker according to the present invention are particularly
useful in a speaker that requires particularly high output sound pressure and a speaker magnetic
circuit used therefor. In particular, since the magnetic flux density distribution of the magnetic
gap can be kept high in a wide range, it is suitable for a large speaker having a large
13-05-2019
11
displacement of the diaphragm or a speaker for a subwoofer device for compensating for the
bass reproduction capability.
[0034]
It is a figure explaining the magnetic circuit for speakers by a desirable embodiment of the
present invention. (Example 1) It is a graph showing distribution of magnetic flux density B in a
magnetic air gap of a magnetic circuit for a speaker. It is a figure explaining the magnetic circuit
for speakers by other preferable embodiment of this invention. (Example 2) FIG. 7 is a view for
explaining a conventional speaker magnetic circuit. It is a figure explaining the conventional
other magnetic circuit for speakers.
Explanation of sign
[0035]
1 Speaker magnetic circuit 2 plate 3 yoke, pole piece 4 main magnet 5 magnetic air gap 6 first
sub magnet 7 pole piece 8 second sub magnet 9 connecting member
13-05-2019
12
Документ
Категория
Без категории
Просмотров
0
Размер файла
22 Кб
Теги
jp2006020139
1/--страниц
Пожаловаться на содержимое документа