JP3952943B2 - Speaker - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a speaker used in various audio equipment and information communication equipment.
[0002]
[Prior art]
A conventional loudspeaker will be described with reference to FIG.
[0003]
FIG. 8 shows a cross-sectional view of a conventional speaker.
[0004]
The magnet 1 magnetized as shown in FIG. 8 is sandwiched between an upper plate 2 and a yoke 3 made of a single iron-based material to constitute an inner magnet type magnetic circuit 4. A frame 6 is coupled to the yoke 3 of the magnetic circuit 4, and a diaphragm 7 is bonded to the peripheral edge of the frame 6. The voice coil 8 coupled to the diaphragm 7 is coupled so as to fit into the magnetic gap 5 of the magnetic circuit 4 (see, for example, Patent Document 1).
[0005]
[Patent Document 1]
JP-A-2001-238297 [0006]
[Problems to be solved by the invention]
The above-described speaker is intended to reduce the thickness of a set such as a mobile phone, and in order to reduce the thickness of the speaker, the thickness of each component is reduced. However, if the material thickness of the yoke 3 is designed to be thin in order to reduce the material of the yoke 3, magnetic saturation occurs, resulting in a magnetic circuit 4 in which the magnetic energy of the magnet 1 cannot be fully utilized, and the magnetic flux density is reduced. It had the subject that it fell and the sound pressure level of a speaker fell.
[0007]
The present invention solves the above-described problems, and provides an excellent speaker capable of improving the sound pressure level of the speaker while reducing the thickness.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the present invention has the following configuration.
[0009]
According to the first aspect of the present invention, the yoke is made of at least two kinds of materials having different saturation magnetic flux densities, and the entire contact portion of the yoke with the magnet is more saturated than the other portions of the yoke. It is composed of a material having a high magnetic flux density . With this configuration, a material with high saturation magnetic flux density is used for the entire contact part with the magnet in the part where magnetic saturation is likely to occur, and the conventional material is used for the part where magnetic saturation is difficult to occur. By changing the material of the bottom surface of the yoke according to the distribution, the magnetic flux of the magnet can be used effectively even if the yoke is thinned, and the sound pressure level of the speaker can be improved.
[0010]
According to a second aspect of the present invention, a plate made of a material having a saturation magnetic flux density higher than that of the yoke is disposed between the bottom surface of the yoke and the magnet. With this configuration, since the magnetic energy of the magnet can be effectively used, it is possible to improve the sound pressure level of the speaker while reducing the thickness.
[0011]
According to a third aspect of the present invention, a recess is provided inside the bottom surface of the yoke, and a plate body made of a material having a saturation magnetic flux density higher than that of the yoke is disposed in the recess. With this configuration, since the magnetic energy of the magnet can be effectively used, it is possible to improve the sound pressure level of the speaker while reducing the thickness.
[0012]
The invention according to claim 4 of the present invention is used for the speaker according to any one of claims 1 to 3 in which a plate body made of a material having a high saturation magnetic flux density is formed into a disk shape. . With this configuration, it is possible to effectively utilize the magnetic energy of the magnet by simply processing a material having a high saturation magnetic flux density.
[0013]
In the invention according to claim 5 of the present invention, the thickness of the plate formed of a material having a high saturation magnetic flux density is continuously varied. With this configuration, a material having a high saturation magnetic flux density is optimally disposed without waste according to the magnetic flux density of the magnet, so that the magnetic energy of the magnet can be effectively utilized while minimizing cost increase.
[0014]
In the invention according to claim 6 of the present invention, the thickness of the plate formed of a material having a high saturation magnetic flux density is varied stepwise. This configuration makes it possible to optimally arrange materials with high saturation magnetic flux density without waste according to the magnetic flux density of the magnet, and to easily construct materials with high saturation magnetic flux density that are difficult to process normally, increasing costs. It is possible to effectively use the magnetic energy of the magnet while minimizing it.
[0015]
The invention according to claim 7 of the present invention is constructed by using permendur as a material having a high saturation magnetic flux density. With this configuration, since the magnetic energy of the magnet can be effectively utilized to the limit by using a material with a particularly high saturation magnetic flux density, it is possible to achieve a great improvement in the sound pressure level of the speaker while achieving a reduction in thickness.
[0016]
In the invention according to claim 8 of the present invention, at least two types of saturation magnetic flux densities are different by sharing a part of yokes of two integrated speakers having a configuration in which sound is generated in opposite directions. It is composed of materials. With this configuration, by arranging a material having a high saturation magnetic flux density in the shared yoke, it is possible to effectively utilize the magnetic energy of the magnet and to improve the sound pressure level of the speaker while reducing the thickness.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0018]
(Embodiment 1)
Hereinafter, the first aspect of the present invention will be described with reference to the first embodiment.
[0019]
FIG. 1 is a cross-sectional view of a speaker according to an embodiment of the present invention.
[0020]
As shown in FIG. 1, a magnetized disk-shaped magnet 21 is sandwiched between a disk-shaped upper plate 22 and a dish-shaped yoke 23 made of two or more kinds of materials having different saturation magnetic flux densities. A magnetic circuit 24 is configured. A ring-shaped frame 26 is coupled to the yoke 23 of the magnetic circuit 24, a disk-shaped diaphragm 27 is bonded to the frame 26, and a cylindrical voice coil 28 coupled to the diaphragm 27 is connected to the magnetic circuit 24. Are arranged so as to fit in the magnetic gap 25.
[0021]
Here, this configuration uses a material with a high saturation magnetic flux density (for example, iron with a low carbon content) for the portion where magnetic saturation is likely to occur, that is, the entire joint portion of the yoke 23 with the magnet 21, that is, the bottom portion 23a. A conventional material (iron having a higher carbon content than the material of the bottom portion 23a) is used for the portion where the saturation hardly occurs, that is, the side wall portion 23b of the yoke 23. With this configuration, even if the yoke 23 is thinned, the magnetic flux of the magnet 21 can be used effectively, so that the sound pressure level of the speaker can be improved.
[0022]
(Embodiment 2)
The second aspect of the present invention will be described below with reference to the second embodiment.
[0023]
FIG. 2 shows a cross-sectional view of the magnetic circuit of the speaker of one embodiment of the present invention.
[0024]
The difference from the first embodiment is that the disc-shaped bottom surface portion 23c of the yoke 23 is made of a material having a high saturation magnetic flux density. With this configuration, it is possible to improve the sound pressure level of the speaker while reducing the thickness.
[0025]
(Embodiment 3 )
Hereinafter, the third embodiment with reference to FIG. 3, described the invention described in particular claim 3 of the present invention.
[0026]
FIG. 3 shows a cross-sectional view of the magnetic circuit of the speaker according to the embodiment of the present invention.
[0027]
The difference from the first embodiment is that a disc-shaped plate body 23e made of a material having a high saturation magnetic flux density is disposed between the bottom surface portion of the yoke 23 and the magnet 21. With this configuration, the magnetic energy of the magnet 21 can be effectively utilized, so that the sound pressure level of the speaker can be improved while reducing the thickness.
[0028]
(Embodiment 4 )
The fourth embodiment of the present invention will be described below with reference to the fourth embodiment.
[0029]
FIG. 4 shows a cross-sectional view of the magnetic circuit of the speaker of one embodiment of the present invention.
[0030]
The difference from the first embodiment is that a recess 23A is provided by a counterbore inside the bottom surface of the yoke 23, and a disc-shaped plate body 23f made of a material having a high saturation magnetic flux density is disposed in the recess 23A. . With this configuration, the magnetic energy of the magnet 21 can be effectively utilized, so that the sound pressure level of the speaker can be improved while reducing the thickness.
[0031]
(Embodiment 5 )
Hereinafter, with reference to the fifth embodiment will be described the invention described in particular claim 5 of the present invention.
[0032]
FIG. 5 shows a cross-sectional view of the magnetic circuit of the speaker of one embodiment of the present invention.
[0033]
A difference from the first embodiment is that a disc 23h is provided between the magnet 21 and the yoke 23 in a disc shape made of a material having a high saturation magnetic flux density and whose thickness is continuously varied from the center toward the outer periphery. That is. With this configuration, the material of the magnet 21 has a high saturation magnetic flux density in a high portion of the magnet 21 with a high magnetic flux density and is optimally disposed in a low portion with little waste. Energy can be used effectively.
[0034]
Therefore, the sound pressure level of the speaker can be improved while reducing the thickness.
[0035]
(Embodiment 6 )
The sixth aspect of the present invention will be described below with reference to the sixth embodiment.
[0036]
FIG. 6 shows a cross-sectional view of the magnetic circuit of the speaker of one embodiment of the present invention.
[0037]
The difference from the first embodiment is that a disk-shaped plate body 23j is formed of a material having a high saturation magnetic flux density, and the material thickness is increased stepwise from the center toward the outside. With this configuration, the plate body 23j made of a material having a high saturation magnetic flux density can be optimally disposed without waste by making the outer side of the magnet 21 having a high magnetic flux density thick. Further, even a material having a high saturation magnetic flux density, which is difficult to process normally, can be easily configured with the plate body 23j having this shape, and the magnetic energy of the magnet 21 can be effectively utilized while minimizing cost increase. Can do.
[0038]
Therefore, the sound pressure level of the speaker can be improved while reducing the thickness.
[0039]
(Embodiment 7 )
The seventh aspect of the present invention will be described below with reference to the seventh embodiment.
[0040]
The present invention uses a permendule as a material having high saturation magnetic flux density used in the Modes 1 6 of the embodiment, which is constituted of any one speaker of claim 6 according to claims 1. According to this configuration, since the magnetic energy of the magnet 21 can be effectively utilized to the limit by using a material having an extremely high saturation magnetic flux density, it is possible to achieve a great improvement in the sound pressure level of the speaker while achieving a reduction in thickness.
[0041]
(Embodiment 8 )
The eighth embodiment of the present invention will be described below with reference to the eighth embodiment.
[0042]
FIG. 7 shows a cross-sectional view of the magnetic circuit of the speaker of one embodiment of the present invention.
[0043]
The difference from the first embodiment is that the bottom surface portion 23k of the yokes 23 of the two integrated speakers having a structure for generating sound in opposite directions is shared and made of a material having a high saturation magnetic flux density. It is. According to this configuration, the shared yoke 23 is formed of a material having a high saturation magnetic flux density, so that the magnetic energy of the magnet 21 can be effectively used efficiently, and the sound pressure level of the speaker can be improved while reducing the thickness. be able to.
[0044]
In particular, in this configuration, the magnetic energy of two magnets 21 passes through the shared portion of the bottom surface portion 23k of the yoke 23 as compared with the case where there is only one speaker. Is very big.
[0045]
【The invention's effect】
As described above, in the speaker of the present invention, the yoke is composed of at least two kinds of materials having different saturation magnetic flux densities. In other words, a material with high saturation magnetic flux density is used for the part where magnetic saturation is likely to occur, and the conventional material is used for the part where magnetic saturation is difficult to occur. As a result, the sound pressure level of the speaker can be improved.
[0046]
As described above, the present invention can provide an excellent speaker capable of improving the sound pressure level of the speaker while being thin, and its industrial value is very large.
[Brief description of the drawings]
1 is a cross-sectional view of a speaker according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of a speaker according to another embodiment of the present invention. FIG. 3 is a cross-sectional view of a speaker according to another embodiment of the present invention. 4 is a sectional view of a speaker according to another embodiment of the present invention. FIG. 5 is a sectional view of a speaker according to another embodiment of the present invention. FIG. 6 is a sectional view of a speaker according to another embodiment of the present invention. FIG. 7 is a cross-sectional view of a speaker according to another embodiment of the present invention. FIG. 8 is a cross-sectional view of a conventional speaker.
DESCRIPTION OF SYMBOLS 21 Magnet 22 Upper plate 23 Yoke 23A Shared yoke 23a Yoke bottom 24 Magnetic circuit 25 Magnetic gap 26 Frame 27 Diaphragm 28 Voice coil

Claims (8)

A magnetic circuit comprising a magnet, a plate and a yoke; a voice coil disposed in a magnetic gap of the magnetic circuit; and a diaphragm coupled to the voice coil, wherein the yoke has at least two types of saturation magnetic flux densities. A loudspeaker constructed of a different material and having the entire contact portion of the yoke with the magnet made of a material having a saturation magnetic flux density higher than that of other portions of the yoke .   The speaker according to claim 1, wherein a plate body made of a material having a saturation magnetic flux density higher than that of the yoke is disposed between the bottom surface of the yoke and the magnet.   The speaker according to claim 1, wherein a concave portion is provided inside the bottom surface portion of the yoke, and a plate body made of a material having a higher saturation magnetic flux density than the yoke is disposed in the concave portion. The speaker according to any one of claims 1 to 3 , wherein the plate body made of a material having a high saturation magnetic flux density has a disc shape. The speaker according to any one of claims 1 to 4, wherein the thickness of the plate formed of a material having a high saturation magnetic flux density is continuously varied. The speaker according to any one of claims 1 to 4, wherein the thickness of the plate formed of a material having a high saturation magnetic flux density is varied stepwise. The speaker according to any one of claims 1 to 6, wherein permendur is used as a material having a high saturation magnetic flux density. A speaker in which a part of two integrated yokes of a speaker having a configuration for generating sound in opposite directions is shared, and the shared yoke is made of at least two kinds of materials having different saturation magnetic flux densities. A speaker in which the entire contact portion of the yoke with the magnet is made of a material having a higher saturation magnetic flux density than other portions of the yoke .

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