close

Вход

Забыли?

вход по аккаунту

?

JP2001326996

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 JP2001326996
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an
electromagnetic acoustic transducer that generates sound by electromagnetic acoustic
conversion.
[0002]
2. Description of the Related Art An electromagnetic acoustic transducer has a magnetic circuit
from the magnet until the magnetic field from the magnet passes through the base member, the
magnetic core and the diaphragm to return to the magnet again, and an electric vibration signal
is transmitted to the coil wound around the magnetic core. The vibration magnetic field
generated by the coil is superimposed on the static magnetic field of the magnetic circuit, and the
vibration of the diaphragm is transmitted to the air to generate sound.
[0003]
When the electromagnetic acoustic transducer is mounted on an electronic device such as a
mobile phone, it is often mounted on a circuit board along with other electronic components.
Therefore, the sound generated by the electromagnetic acoustic transducer is transmitted
through the internal space of the device, passes through the gap of the device case or a
predetermined opening, and is emitted to the outside of the device. At this time, in order to
03-05-2019
1
maintain the sound pressure outside the device at a certain level or more, it is necessary to
reduce the acoustic loss from the electroacoustic transducer to the outside of the device as much
as possible. As a measure against this, an acoustic guide member is provided in the gap between
the electroacoustic transducer and the device case to prevent the diffusion of acoustics.
[0004]
Such an acoustic guide member is considered to be separately attached when the circuit board is
incorporated into the device case in the assembly process of the device, but it leads to an
increase in the number of parts and the number of assembly steps. Therefore, handling as a
single part with an acoustic guide member contributes to cost reduction.
[0005]
Conventionally, when attaching an acoustic guide member to an electromagnetic acoustic
transducer, it has been fixed using a double-sided adhesive tape or an adhesive. However, the
acoustic guide member is made of an elastomer, silicone rubber, or the like. In the case of (1),
sufficient fixing strength was not obtained because of poor adhesion to the adhesive tape and the
adhesive. Therefore, the acoustic guide member may fall off during component transportation or
assembly. In addition, when the adhesive tape or the adhesive agent protrudes in the attaching
process, it may cause a problem in the subsequent process, and the process control is
complicated.
[0006]
As related prior art, there are JP-A-10-20864 and JP-A-11-249662. In the former case, a locking
claw is formed on the sound leakage prevention member, and the sound leakage hole is hooked
and fixed to the sound emission hole. In the latter case, a locking hole is formed in the vicinity of
the sound output hole and fixed by fitting.
[0007]
However, since the shape of the space around the sound emission hole greatly affects the
03-05-2019
2
acoustic characteristics, even if the locking claw of the sound leakage preventing member can
not achieve the initial acoustic characteristics. Further, even if designed in anticipation of the
influence of the locking claw, the product specification without the sound leakage preventing
member can not be coped with, resulting in useless variety increase. Similarly for the latter, if it is
necessary to increase the fixing strength of the sound leakage preventing member, it is necessary
to increase the size of the locking hole, which results in an adverse effect on the acoustic
characteristics.
[0008]
An object of the present invention is to provide a compact, high sound pressure electroacoustic
transducer in which the fixing strength between the elastic member and the transducer body is
high without adversely affecting the acoustic characteristics of the transducer body.
[0009]
SUMMARY OF THE INVENTION According to the present invention, a diaphragm made of a
magnetic material, an electromagnetic coil for supplying an oscillating magnetic field to the
diaphragm, a diaphragm and an electromagnetic coil, and the diaphragm being generated And a
resilient member for guiding the sound from the sound emission hole, the elastic member
engaging with the outer surface of the housing member It is an electroacoustic transducer
characterized by having a joint part.
[0010]
According to the present invention, by providing the elastic member with the engaging portion
engaged with the outer surface of the housing member, it is possible to maintain appropriate
acoustic characteristics without causing a change in the space shape around the sound emission
hole, and the elastic member Can be sufficiently high.
Moreover, since it can fix without using an adhesive tape and an adhesive agent, a manufacturing
man-hour and quality control cost can be reduced.
[0011]
Further, the present invention accommodates a diaphragm made of a magnetic material, an
electromagnetic coil for supplying an oscillating magnetic field to the diaphragm, a diaphragm
and an electromagnetic coil, and emits the sound generated by the diaphragm to the outside. A
03-05-2019
3
housing member having a sound emission hole formed therein, and an elastic member for
guiding a sound from the sound emission hole, the housing member has a leg having a
predetermined height from the bottom surface, and the elastic member is a leg It is an
electromagnetic acoustic transducer characterized by having an engaging part which engages
with a part.
[0012]
According to the present invention, by providing the elastic member with the engaging portion
engaged with the leg portion of the housing member, it is possible to maintain appropriate
acoustic characteristics without causing a change in the space shape around the sound emission
hole and The fixing strength of the member can be sufficiently high.
Moreover, since it can fix without using an adhesive tape and an adhesive agent, a manufacturing
man-hour and quality control cost can be reduced.
[0013]
Also, by forming a leg portion of a predetermined height on the bottom surface of the housing
member, a fixed space can be secured between the bottom surface of the housing member and
the circuit board, and other electronic components can be mounted in this space. The mounting
density of the circuit board is significantly improved.
[0014]
Further, the present invention accommodates a diaphragm made of a magnetic material, an
electromagnetic coil for supplying an oscillating magnetic field to the diaphragm, a diaphragm
and an electromagnetic coil, and emits the sound generated by the diaphragm to the outside. A
housing member in which a sound emission hole is formed, an elastic member for guiding the
sound from the sound emission hole, and a winding member for winding and fixing the elastic
member and the housing member It is an electromagnetic acoustic transducer.
[0015]
According to the present invention, by winding and fixing the elastic member and the housing
member using the winding member, appropriate acoustic characteristics can be maintained
03-05-2019
4
without causing a change in the space shape around the sound emission hole. The fixing strength
of the elastic member can be sufficiently high.
Moreover, since it can fix without using an adhesive tape and an adhesive agent, a manufacturing
man-hour and quality control cost can be reduced.
[0016]
DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an exploded perspective view
showing an example of an electromagnetic acoustic transducer according to the present
invention.
2 (a) is a front view as viewed from the sound output hole 11 side, and FIG. 2 (b) is a bottom
view.
Fig.3 (a) is a side view, FIG.3 (b) is an end elevation along the AA line of Fig.2 (a).
[0017]
The electromagnetic acoustic transducer 1 is configured such that the base 24, the magnetic core
22, the coil 23, the magnet 25, the support ring 26, and the diaphragm 20 are accommodated on
the lower housing 30, and the upper housing 10 is mounted. It has a flat shape. The dimensions
excluding the leg 33 are, for example, about width W 10 mm × length D 11 mm × height 3 mm,
and the dimensions of the leg 33 are, for example, height Ha = 2.7 mm and length Da = 2.2 mm.
[0018]
The lower housing 30 is formed of a synthetic resin such as a thermoplastic resin, and has an
annular protrusion 31 having a circumference of about 5/6, and a part of a disc is cut out on the
inside of the protrusion 31 A plate-like base 24 having a substantially D-shape is mounted. A
cylindrical magnetic core 22 is erected at the center of the base 24, and a coil 23 is wound
around the magnetic core 22. The base 24 and the magnetic core 22 may be formed of a
03-05-2019
5
magnetic material, and both may be integrated by press fitting or the like to form a single pole
piece member.
[0019]
The magnet 25 has an annular shape smaller than the inner diameter of the protrusion 31 and is
disposed concentrically with the magnetic core 22 on the base 24. An annular internal space is
secured between the magnet 25 and the coil 23.
[0020]
The support ring 26 is formed of a nonmagnetic material, and the outer diameter of the support
ring 26 is slightly smaller than the inner diameter of the projection 31 and is disposed in contact
with the base 24. A plurality of annular steps are formed on the inner side of the support ring 26.
Among them, the back side of the projection 27 abuts on the upper surface and the outer surface
of the magnet 25 to regulate the position of the magnet 25. A horizontal pedestal 28 is annularly
formed on the upper portion of the projection 27. The disc-shaped diaphragm 20 is mounted on
the pedestal 28, and the diaphragm 20 is positioned by an annular step.
[0021]
The diaphragm 20 is formed of a magnetic material and is supported by the pedestal 28 of the
support ring 26 at its peripheral edge, and a constant gap is secured between the center of the
back surface of the diaphragm 20 and the tip of the magnetic core 22. A disk-shaped magnetic
piece 21 is fixed at the center of the front surface of the diaphragm 20, and the mass of the
diaphragm 20 is increased to improve the vibration efficiency of air.
[0022]
The upper housing 10 is formed of a synthetic resin such as a thermoplastic resin, and formed in
a box shape so as to fit the shape of the lower housing 30. The upper housing 10 and the lower
housing 30 are joined by an adhesive, ultrasonic welding or the like.
03-05-2019
6
[0023]
A sound output hole 11 is formed on the side surface of the upper housing 10 closer to the leg
33 among the side surfaces. Since a reinforcement bridge is provided at the center of the sound
emission hole 11, it looks like two openings in appearance. Inside the upper housing 10, as
shown in FIG. 3B, a projection 15 is formed in contact with the upper surface of the support ring
26 to regulate the position of the support ring 26.
[0024]
In the state where the upper housing 10 is mounted, the protrusion 14 is formed at the center of
the ceiling surface of the upper housing 10 with a predetermined gap from the magnetic piece
21 of the diaphragm 20. The projection 14 has a function to prevent the diaphragm 20 from
falling off or being deformed when a strong impact is applied to the converter main body, and is
formed at a height that does not disturb normal vibration of the diaphragm 20.
[0025]
A leg portion 33 is formed on the bottom surface of the lower housing 30 near the sound output
hole 11. As shown in FIG. 2 (a), in order to facilitate mold removal during molding, the entire
lower side has a tapered shape. Further, as shown in FIG. 2B, the rear surface of the leg portion
33 is formed in a concave curved shape in order to secure a space as large as possible behind the
leg portion 33. The leg 33 may be formed integrally with the lower housing 30 or may be
configured as a separate member.
[0026]
By providing such legs 33, a component space of, for example, height Ha = 2.7 mm, length about
9 mm, width W10 mm can be secured on the bottom surface of lower housing 30, and therefore
the mounting density of the circuit board can be increased. .
[0027]
03-05-2019
7
As shown in FIG. 3A, cylindrical storage holes are formed at two positions on both sides of the
bottom surface of the leg portion 33, and the coil spring-like terminals 52 are respectively
stored.
In the lower housing 30, two conductive members 50 are disposed along the both ends by insert
molding or the like. The rear end of each conductive member 50 is exposed at the upper surface
corner of the lower housing 30 to form a connection land 50a, and the front end of the
conductive member 50 is exposed at the upper surface corner of the lower housing 30 to form a
connection land 50b.
[0028]
The lead wires 23a and 23b of the coil 23 are drawn out to the connection land 50a through the
notch of the base 24. The connection lands 50 a and the lead wires 23 a and 23 b of the coil 23
are electrically connected by soldering or the like to form a connection processing unit 51. The
connection land 50 b and the root side of the terminal 52 are electrically connected by soldering
or the like to form a connection processing unit 53.
[0029]
By arranging the connection processing parts 51 and 53 at the upper corner of the upper surface
of the lower housing 30, the space around the support ring 26 can be effectively used, the parts
can be thinned, and the height at the time of mounting can be reduced. .
[0030]
Next, the operation will be described.
Referring to FIG. 3B, magnet 25 is magnetized in the thickness direction. For example, when the
bottom surface of magnet 25 is magnetized to the N pole and the top surface is magnetized to
the S pole, magnet 25 comes out from the bottom surface of magnet 25 Magnetic lines of force
pass along the path of the peripheral portion of the base 24 → the central portion of the base 24
→ the magnetic core 22 → the central portion of the diaphragm 20 → the peripheral portion of
the diaphragm 20 → the upper surface of the magnet 25 to form a closed magnetic circuit. Do.
The magnet 25 has a function of supplying a static magnetic field to such a magnetic circuit, and
03-05-2019
8
the diaphragm 20 is stably supported in a state of being attracted to the magnetic core 22 and
the magnet 25 by the static magnetic field.
[0031]
The coil 23 wound around the magnetic core 22 supplies an oscillating magnetic field to the
magnetic circuit when the electric vibration signal is supplied from the circuit board via the
terminal 52 and the lead wires 23a and 23b. Then, the diaphragm 20 vibrates due to the
superposition of the static magnetic field and the oscillating magnetic field, and the air on the
upper surface side and the air on the bottom surface of the diaphragm 20 vibrate.
[0032]
The front space Va of the diaphragm 20 forms a resonance chamber, and when the vibration
frequency of the diaphragm 20 substantially matches the resonance frequency of the resonance
chamber, a sound with a high sound pressure level is generated. The sound is emitted from the
sound emission hole 11 to the outside.
[0033]
At this time, by forming the sound output hole 11 at a position closer to the upper surface of the
upper housing 10 than the bottom surface of the leg 33 on the side surface of the upper housing
10, the acoustic transmission space from the front space of the diaphragm 20 to the sound
output hole 11 Has a relatively flat frequency characteristic, and a compact, high sound pressure
electromagnetic acoustic transducer can be realized.
[0034]
FIG. 4 is a partial cross-sectional view showing the electroacoustic transducer 1 mounted on an
electronic device.
Here, a mobile phone is illustrated as an electronic device.
Various electronic components are mounted on both sides of the circuit board 80 and housed in
casings 83 and 84.
03-05-2019
9
[0035]
A hollow gasket 86 made of a rubber material or the like is attached to the electromagnetic
acoustic transducer 1, and the whole is sandwiched between the casing 83 and the circuit board
80. At this time, since the coil spring-like terminals 52 elastically contact the circuit board 80, an
electrical connection becomes possible, and a soldering-free assembly is realized. The gasket 86
has a function of communicating the sound emission hole 11 with the external opening 85 to
guide the sound from the sound emission hole 11, and the hollow portion of the gasket 86 works
as a resonance chamber of the diaphragm 20.
[0036]
Further, since the leg portion 33 is provided on the bottom surface of the electromagnetic
acoustic transducer 1 closer to the sound output hole 11, the electronic component can be
disposed behind the leg portion 33, which contributes to high density mounting of the electronic
component.
[0037]
The electromagnetic acoustic transducer 1 according to the present invention is of a closed type
that does not emit the back surface sound of the diaphragm 20 to the outside.
Therefore, even when the speaker 81 is disposed, for example, in the vicinity of the
electromagnetic acoustic transducer 1, the back sound does not leak to the speaker opening 82
and become offensive to a call, and high-density mounting of electronic components can be
realized.
[0038]
Further, by forming the electromagnetic acoustic transducer 1 in a closed type without the back
surface acoustic emission hole, the possibility of foreign matter entering from the emission hole
is eliminated, which contributes to the improvement of the reliability of the parts.
[0039]
03-05-2019
10
FIG. 5 is an exploded perspective view showing the mounting state of the gasket 86. As shown in
FIG.
The gasket 86 includes a front surface abutting portion 88 in close contact with the front surface
of the upper housing 10 and the leg portion 33, an upper surface sheet portion 89 in close
contact with the upper surface of the upper housing 10, and a horn portion 87 extending in a
tapered shape from the sound output hole 11 It consists of The inlet side opening of the horn
portion 87 is shaped to cover the periphery of the sound output hole 11, and the outlet side
opening 87a of the horn portion 87 is in close contact with the outer opening 85 of the device
casing 83 as shown in FIG. On the left and right sides of the front abutment portion 88,
sandwiching portions 88a sandwiching the front side of the electromagnetic acoustic transducer
1 are formed.
[0040]
FIG. 6 is a perspective view showing a first embodiment of the present invention. This is viewed
from the bottom rear side, and the top sheet portion 89 of the gasket 86 and the upper housing
10 and the lower housing 30 of the electromagnetic acoustic transducer 1 are wound and fixed
by a band member 90. The band member 90 is formed of a shrink film (heat shrink film), rubber,
or the like.
[0041]
By adopting such a fixing method, since it is possible to fix with high strength without using an
adhesive tape or an adhesive, it is possible to reduce the number of manufacturing steps and the
quality control cost.
[0042]
FIG. 7 is a perspective view showing a second embodiment of the present invention.
This is viewed from the bottom rear side, and a band portion 88 b is integrally formed so as to
surround the leg portion 33 from the left and right sides of the front abutment portion 88.
03-05-2019
11
[0043]
The band portion 88b engages with the leg portion 33, so that high strength can be fixed without
using an adhesive tape or an adhesive, so that the gasket 86 can be reliably prevented from
falling off, reducing the number of manufacturing steps and the quality control cost. it can.
[0044]
FIG. 8 is a perspective view showing a third embodiment of the present invention.
This is viewed from the bottom rear side, and the engaging projection 88 c is integrally formed
so as to extend rearward from the center of the lower side of the front abutment portion 88. At
the center of the bottom surface of the leg portion 33, an engagement groove 33a which is
substantially the same as the width and thickness of the neck of the engagement projection 88c
is formed.
[0045]
When the engaging projection 88c engages with the leg portion 33, it can be fixed with high
strength without using an adhesive tape or adhesive, so that the gasket 86 can be reliably
prevented from falling off, and the manufacturing man-hour and quality control cost Can be
reduced.
[0046]
FIG. 9 is a perspective view showing a fourth embodiment of the present invention.
This is viewed from the bottom rear side, and a pair of left and right engaging claws 88d engaged
with the rear surface of the leg 33 from the left and right sides of the front abutment portion 88
are integrally formed.
[0047]
Such engagement claws 88d engage with the leg portions 33, so that they can be fixed with high
03-05-2019
12
strength without using an adhesive tape or adhesive, so that the gasket 86 can be reliably
prevented from falling off, and the manufacturing man-hour and quality control cost can be
reduced. It can be reduced.
[0048]
As described above in detail, according to the present invention, the elastic member may be
provided with an engaging portion which engages with the outer surface or the leg portion of the
housing member, or the elastic member and the housing member may be wound and fixed. Thus,
since the gasket 86 can be fixed with high strength without using an adhesive tape or an
adhesive, dropping off of the gasket 86 can be reliably prevented, and the number of
manufacturing steps and the quality control cost can be reduced.
Moreover, according to the fixing structure of the present invention, appropriate acoustic
characteristics can be maintained without causing a change in the space shape around the sound
emission hole.
[0049]
Brief description of the drawings
[0050]
1 is an exploded perspective view showing an example of the electromagnetic acoustic
transducer according to the present invention.
[0051]
2 (a) is a front view as viewed from the sound output hole 11 side, and FIG. 2 (b) is a bottom
view.
[0052]
3 (a) is a side view, and FIG. 3 (b) is an end view taken along the line A-A of FIG. 2 (a).
[0053]
4 is a partial cross-sectional view showing a state in which the electromagnetic acoustic
03-05-2019
13
transducer 1 is mounted on an electronic device.
[0054]
5 is an exploded perspective view showing the mounting state of the gasket 86.
[0055]
6 is a perspective view showing a first embodiment of the present invention.
[0056]
7 is a perspective view showing a second embodiment of the present invention.
[0057]
8 is a perspective view showing a third embodiment of the present invention.
[0058]
9 is a perspective view showing a fourth embodiment of the present invention.
[0059]
Explanation of sign
[0060]
DESCRIPTION OF SYMBOLS 1 electromagnetic acoustic converter 10 upper housing 11 sound
emission hole 20 diaphragm 22 magnetic core 23 coil 23a, 23b lead wire 24 base 25 magnet 26
support ring 30 lower housing 33 leg 50 conductive member 50a, 50b connection land 51, 53
connection processing Section 52 Terminal 86 Gasket 88b Band 88c Engaging projection 88d
Engaging claw 90 Band member
03-05-2019
14
Документ
Категория
Без категории
Просмотров
0
Размер файла
24 Кб
Теги
jp2001326996
1/--страниц
Пожаловаться на содержимое документа