close

Вход

Забыли?

вход по аккаунту

?

JP2001239210

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 JP2001239210
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the
structure of a multi-functional sounding body which responds to a plurality of frequency bands
and outputs sound frequency or lower frequency vibration.
[0002]
2. Description of the Related Art A vibration (vibration) which can be sensed in response to an
electrical input at an acoustic frequency of, for example, several hundreds to several kilohertz,
and also to an electrical input at a low frequency of around 10 to 100 Hz. A multi-function
sounding body that also outputs is known. Since this is a single acoustic transducer and can
generate a plurality of types of signals, it is highly effective as a means for downsizing and cost
reduction of devices such as mobile phones. FIGS. 4 and 5 schematically show the structure of a
conventional multi-function sound generator.
[0003]
FIG. 4 is a cross-sectional view schematically showing the structure of a multi-function sounding
body according to a first prior art example. A cover 1 is a case made of a synthetic resin and has
a substantially box shape. A diaphragm 2 is for sound output, and its peripheral portion is fixed
to the cover 1 so that the voice coil 3 is integrated. A cylindrical permanent magnet 5 is
13-05-2019
1
magnetized in the axial direction of the cylinder and fixed to the central portion of a cylindrical
cup-shaped yoke 7 made of a high magnetic permeability material. A top plate 6 is a pole piece
which is also made of a high permeability material and is fixed to the upper end of the
permanent magnet 5.
[0004]
The permanent magnet 5, the top plate 6 and the yoke 7 constitute a magnetic circuit. A
suspension spring 8 is fixed to the yoke 7. The suspension spring 8 has a plurality of arm-like
portions (represented only in cross section) extending outward of the yoke 7, and the outer end
of this arm is fixed to the cover 1. Therefore, the magnetic circuit is elastically suspended on the
arm-like portion of the suspension spring 8 and can integrally vibrate in the axial direction
(vertical direction in the figure). The ring-shaped part of the outer periphery of the yoke 7 has an
additional mass 9 and occupies the outside of the main part of the magnetic circuit, and serves as
an additional mass for lowering the natural frequency of the magnetic circuit sufficiently lower
than the magnetic flux passage. Have. Therefore, the yoke 7 may be made of different material
and coupled.
[0005]
The magnetic flux generated by the permanent magnet 5 is concentrated in a ring-shaped
magnetic gap between the peripheral side surface of the top plate 6 and the inner surface near
the cup-shaped upper end of the yoke 7, and a cooperative magnetic field is formed. A voice coil
3 is inserted in the magnetic gap, and when a signal current of an acoustic frequency flows in the
voice coil, the diaphragm 2 vibrates to emit sound. The cover 1 is fixed to an outer wall or a
circuit board (not shown) of the small-sized electroacoustic apparatus.
[0006]
With such a configuration, when a drive current is input to the voice coil 3 from an external
circuit (not shown), an electromagnetic force is generated relatively between the voice coil 3 and
the magnetic circuit. If the drive current is an acoustic or audio frequency, the magnetic circuit
does not respond because its natural frequency is much lower, and only the diaphragm 2 vibrates
to output an acoustic. However, if the drive current has a low frequency close to the natural
frequency of the magnetic circuit, the diaphragm 3 hardly responds, and the magnetic circuit
13-05-2019
2
resonates and vibrates in the axial direction with a large amplitude. Then, in an environment that
dislikes sound, or conversely, in an environment where noise is large and the sound signal is
inappropriate, a signal is generated due to silent and sensational vibration.
[0007]
Generally, a magnetic circuit always has a leakage flux, and it is not preferable to reach a distant
place because it affects other parts and devices, so it is not preferable to have some kind of antimagnetic measures. The ring-shaped groove 11 provided in the yoke 7 in FIG. 4 is provided to
prevent the leakage of the magnetic flux. That is, since the inside of the groove 11 provided in
the high magnetic permeability material has high magnetic resistance, the permanent magnet 5
→ top plate 6 → magnetic air gap → upper end of the yoke 7 → lower end of the yoke 7 →
permanent magnet 5 It is less likely to cross this part and leakage to the outside will be reduced,
ie magnetic shielding will take place and the flux will be concentrated in the required magnetic
gap.
[0008]
FIG. 5 is a cross-sectional view showing an outline of the structure of a multi-function sound
generator according to a second prior art. The structure is almost the same as that of the first
prior art shown in FIG. 4, and the reference numerals given to the respective parts are also
common. The difference from the first conventional example is the leakage magnetic flux
preventing structure, and in the second conventional example, the magnetic shielding member
10 is made of a material having a magnetic permeability higher than that of the material of the
yoke 7 instead of the grooves. As close to the magnetic gap. Most of the magnetic flux emanating
from the permanent magnet passes through the inside of the magnetic reluctance ring 10 with
low reluctance, and the ratio of the leakage magnetic flux decreases.
[0009]
The above-mentioned prior art all adopt an inner magnet type structure in which the yoke
surrounds a permanent magnet located at the central shaft. On the other hand, there is an
external magnet type structure in which the permanent magnet is ring-shaped and the main part
of the magnetic flux generated by the permanent magnet is concentrated in the magnetic gap
inside the permanent magnet ring. Try to adopt the configuration. The external magnet type
13-05-2019
3
structure can easily make the volume of the permanent magnet larger than that of the internal
magnet type, and can utilize large magnetic energy. Also, if the volume of the permanent magnet
is reduced, there is an advantage that a relatively thin magnetic circuit can be designed. However,
since the permanent magnet is on the outer side, the leakage flux to the outside tends to be a
little large, and it is necessary to effectively suppress this, but a highly effective leakage flux
prevention structure in the outer ear type structure has been proposed Absent.
[0010]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a structure
capable of effectively reducing the leakage flux to the outside of a multifunctional sounding body
adopting an external magnet type structure and sufficiently exhibiting the advantages of the
external magnet type. It is.
[0011]
SUMMARY OF THE INVENTION In order to solve the above problems, the multifunctional
sounding body of the present invention has the following features.
(1) A cover, a diaphragm supported by the cover and vibrating by receiving an electromagnetic
force of an acoustic frequency, and a cover having a relatively low frequency which is elastically
supported by the elastic member by the elastic member, the diaphragm And a permanent magnet
including a magnetic field for generating the electromagnetic force, and comprising a relatively
large mass magnetic circuit, wherein the diaphragm or the magnetic circuit is mainly adapted to
the electric input of a plurality of frequency bands. In the multi-function sounding body that
vibrates in response to this, the permanent magnet forms a ring shape to form the magnetic field
inside, and the magnetic flux leaks to the outside of the housing outside the permanent magnet.
A ring-shaped magnetic shielding member made of a high permeability material is disposed to
reduce the magnetic field.
[0012]
In addition, the multifunctional sounding body of the present invention may further include at
least one of the following features. (2) The elastic member is a plate-like member disposed in
parallel to two sheets, and the magnetic shielding member is disposed so as to be sandwiched by
the two elastic members.
13-05-2019
4
[0013]
(3) The magnetic shielding member is insert molded in the cover.
[0014]
(4) The cover is made of a synthetic resin material mixed with a high permeability material
powder.
[0015]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a cross-sectional view of
a multi-function type sounding body which is an example of an embodiment of the present
invention.
About the part which has commonality to what was already demonstrated by FIG. 5 and FIG. 6,
the same symbol and name are attached | subjected and the overlapping description is
abbreviate | omitted.
The following parts are mainly different from the conventional example. (1) The permanent
magnet 5 has a ring shape (magnetization in the thickness direction) instead of a cylindrical
shape and occupies the outside of the magnetic circuit to form a so-called external magnet type
structure. Along with this, the pole piece 4 corresponding to the yoke 7 of the conventional
example has a soft magnetic portion of high magnetic permeability that is not the outer
peripheral portion but the core portion as shown in the perspective view of FIG. The top plate 6
is also ring-shaped unlike the prior art.
[0016]
(2) The upper and lower suspension springs 8a and 8b, which are elastic members for elastically
supporting the magnetic circuit, are integrally formed on the upper cover 1a and the lower cover
1b by insert molding. Being standardized. This structure and the processing method therefor are
the eyes of the present invention. In addition, the planar shape of the cover is not square but
circular. The upper and lower covers are joined together during assembly of the multifunctional
13-05-2019
5
sounding body (the upper and lower arms are oriented 90 ° differently). In the inside, the
magnetic circuit is elastically suspended by the respective arms of the upper and lower
suspension springs as in the prior art.
[0017]
(3) In the external magnet type structure, a strong air gap magnetic flux can be obtained using a
large volume permanent magnet, but the magnetic flux leaking from the permanent magnet to
the outside tends to be relatively large. Therefore, the outside slightly away from the outer
periphery of the permanent magnet 5 is surrounded by the magnetic shielding ring 10 made of a
high magnetic permeability material, and the leakage flux is collected in the magnetic shielding
ring to minimize the leakage to the outside. In the present embodiment, the magnetic shield ring
10 also plays a role in assembling the sounding body.
[0018]
FIG. 2 (a) is a plan view of the upper cover in one example of the embodiment of the present
invention described above, and FIG. 2 (b) is a plan view of the lower cover as well. . The upper
suspension spring 8a and the lower suspension spring 8b are both flat and have concentric ring
portions on the inner and outer sides, and both rings are connected by a pair of substantially
semi-circular arm portions arranged point-symmetrically There is. The outer ring is molded in the
cover, the inner ring is shown in FIG. 1, the lower suspension spring 8b is at the step on the
lower surface of the pole piece 4, and the upper suspension spring 8a is at the step on the upper
surface of the top plate 6. It is fixed by press fitting.
[0019]
Although the upper cover 1a and the lower cover 1b both have a substantially ring shape, the
upper cover 1a has a terminal portion 1f which is a rectangular projecting portion. Two terminal
pins 1g are planted in this part. At the time of assembling the multi-function sounding body, lead
wires from both ends of the voice coil 3 are connected to these. Further, a part of the upper
suspension spring 8a penetrates the terminal portion 1f and extends to the outside, which
becomes the ground terminal 8d. The lower cover 1b and the lower suspension spring 8b are
insert-molded with the lower portion of the magnetic shield ring 10. The upper portion of the
magnetic shield ring 10 protrudes from the upper surface of the lower cover 1b. A ring-shaped
13-05-2019
6
notch for accommodating this portion is provided on the lower surface of the upper cover 1a,
and when the upper and lower covers are put together and fixed and integrated, the magnetic
shield ring 10 also serves to position both of them. A diaphragm 2 with a concentric crease is
adhered to the upper portion of the upper cover 1a at its outer peripheral portion.
[0020]
Although one example of the embodiment of the present invention has been described above, it
goes without saying that the present invention is not limited to this embodiment. For example,
the shape of the cover, the shape and number of arms of the suspension spring, the number of
arms, the shape of the diaphragm, the shape of the permanent magnet, the shape of the pole
piece, the shape of the top plate, and the additional mass The shape of the other details, the
addition of other members, the material of each part, and the like can be variously changed.
[0021]
(1) In the present invention, since the ring-shaped magnetic shielding member is disposed on the
outside of the ring-shaped permanent magnet, the leakage flux can be reduced even in the
external-magnet-type structure despite the simple structure. There is an effect that can be made
small enough.
[0022]
(2) Further, by arranging the ring-shaped magnetic shielding member between the two elastic
members, it is possible to realize an effective magnetic shielding structure without increasing the
outer diameter of the multi-function sounding body.
[0023]
(3) Further, the configuration in which the magnetic shielding member is insert-molded in the
cover has an effect of being able to automatically arrange the magnetic shielding member at the
correct position inside the multifunctional sounding body.
In addition, there is an effect that the positioning of the two covers can be correctly performed
through the magnetic shielding member.
13-05-2019
7
[0024]
(4) Further, by using a synthetic resin material in which material powder of high magnetic
permeability is mixed in the cover, it is possible to share the magnetic shielding effect on the
cover and to perform magnetic shielding more effectively.
13-05-2019
8
Документ
Категория
Без категории
Просмотров
0
Размер файла
17 Кб
Теги
jp2001239210
1/--страниц
Пожаловаться на содержимое документа