JP2000358296A - Speaker and speaker device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance magnetomotive force, to enlarge the magnetic flux density in a magnetic gap and to effectively utilize the whole magnetomotive force by arranging a plate consisting of a magnetic body being larger than the outer diameter of first and second magnets at the upper side and/or the lower side of the first and second magnets. SOLUTION: A speaker device is provided with a second magnet 6 which is constituted of a ring shape ferrite or the like with a diameter which is nearly the same as the outer diameter ϕM of the first magnet 1 and a second disk- shaped or ring-shaped plate 11 having the diameter ϕP being sufficiently larger than the outer diameter ϕM of the second magnet 6. The second plate 11 is constituted of the magnetic body having a high magnetic permeability. When each thickness of the first and the second magnets 1 and 6 is made to be T1, a diameter difference 2D in the case the diameters of the first and the second plates 2 and 11 are ϕP and the diameters of the first and the second magnets 1 and 6 are ϕM is indicated by 2D=ϕP-ϕM. In this case, D is selected to be >=T1 so that the magnetic flux density of the magnetic gap part is increased by about 10%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker and an improvement of a speaker having a magnetic circuit capable of increasing a magnetic flux density in a magnetic gap of the speaker and the speaker.

[0002]

2. Description of the Related Art FIG. 10 shows a magnetically shielded speaker 10 which has been frequently used. The magnetic circuit of the magnetic shield type speaker 10 has a columnar center pole 3a at the center of a yoke 3 made of a substantially disk-shaped metal, is integrated with the yoke 3, and has a substantially inverted T-shaped cross section. ing. On the lower side of the yoke 3, a concentric second magnet 6 serving as a cancel magnet magnetized with S and N in the thickness direction is bonded via an adhesive or the like.

[0003] On the yoke 3, a first magnet 1 concentrically formed as a main magnet and magnetized with N and S in the thickness direction and opposite to the second magnet 6 in the thickness direction is bonded with an adhesive. A plate 2 made of a concentric metal is joined to the first magnet 1 with an adhesive or the like, and a magnetic circuit from the first magnet 6 to the plate 2 is surrounded by a shield cover 7 made of a bottomed cylindrical metal. As a result, one pole (N pole) of the second magnet 6 and the outer peripheral portion of the plate 2 are opposed to each other, so that it is of a magnetic-shield type.

A frame 5 pressed with metal or the like in a funnel shape is fixed on the upper side of the plate 2 with rivets, and a voice is inserted into a magnetic gap 4 formed between the inner diameter of the plate 2 and the outer diameter of the center pole 3a. Voice coil bobbin 9 wound with coil 8
Is inserted into the outer diameter of the guide spacer inserted into the center pole 3a, and the inner diameter of the corrugated concentric damper 14 inserted into the middle position of the voice coil bobbin 9 is bonded to the outer diameter of the voice coil bobbin 9 with an adhesive. Then, by joining the outer diameter to the outer periphery of the bottom of the frame 5, the voice coil 8 including the voice coil bobbin 9 is pivotally attached to the frame 5 so as to be vertically swingable.

Further, an inner diameter of a diaphragm 15 having a cone-shaped fixed edge or a free edger 16 is joined to an upper end of the voice coil bobbin 9, and an outer periphery of the edge 16 is joined to a maximum opening of the frame 5 via a gasket 18. By joining the upper opening of the voice coil bobbin 9 with a dome-shaped cap 17 for preventing dust from entering, the vibration system is pivotally attached to the frame 5 so as to swing up and down.

[0006]

According to the magnetic shield type speaker described with reference to FIG. 10, there are two types of leakage magnetic fluxes φ _L1 and φ _L2 generated between the outer and inner diameters of the first and second magnets 1 and 6. The total magnetomotive force obtained by adding the first and second magnets 1 and 6 could not be effectively used in the magnetic gap 4, and only about 1/3 of the total magnetomotive force could be used. In other words, if the magnetomotive force of one magnet is set to “1” in the magnetic circuit of the anti-magnetic type, even if two magnets 1 and 6 are used,
Due to the relationship that they were joined to each other with opposite polarities instead of double magnetomotive force, only a magnetomotive force of about 1.2 could be produced.

SUMMARY OF THE INVENTION The present invention has solved the above-mentioned problems. The problem to be solved by the present invention is that a magnetic plate or yoke is interposed below a second magnet which is a cancel magnet. Just by making it sufficiently larger than the outer diameter, the magnetomotive force is increased and the magnetic flux density in the magnetic gap is reduced to 1
An object of the present invention is to provide a speaker and a speaker device capable of effectively utilizing the total magnetomotive force by increasing the value by about 0%.

[0008]

The loudspeaker of the present invention has a first feature.
And a speaker having a magnetic circuit using the second magnet, wherein a plate made of a magnetic material larger than the outer diameter of the first and second magnets is placed above and below the first and second magnets, or at least. It is arranged on either one.

The speaker device according to the present invention comprises a magnetic circuit having first and second magnets, and a plate made of a magnetic material having a diameter larger than the outer diameter of the first and second magnets, which is above and below the first and second magnets. A speaker provided on the side or at least one of them is disposed in a speaker box.

According to the loudspeaker and the loudspeaker apparatus of the present invention, a plate made of a magnetic material having a diameter sufficiently larger than the outer diameter of the magnet is provided on the upper and / or lower side or at least one of the first and second magnets. Just by arranging it, the magnetic flux density of the magnetic gap can be increased by about 10%.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a speaker according to the present invention will be described below in detail with reference to FIGS. FIG. 1 is a side sectional view of a speaker of the present invention, FIG. 2 is a side sectional view of another speaker of the present invention, and FIGS. 3 and 4 are side sectional views of still another speaker of the present invention.

FIGS. 1 to 4 constitute a magnetic circuit of a magnetic shield type in the same manner as described in detail with reference to FIG.

In the magnetic circuit of the speaker 10 shown in FIG. 1, a columnar center pole 3a and a magnet guide 3b composed of a step formed in a disk-like portion are integrated at the center of a yoke 3 made of substantially disk-shaped pure iron or the like. The cross section is formed in a substantially inverted T-shape.

On the yoke 3, an inner diameter portion of the first magnet 1 constituting a main magnet such as a ring-shaped ferrite is fitted into a magnet guide 3b of the yoke 3 and joined via an adhesive.

Next, a gap guide having a predetermined gap width is inserted into the center pole 3a, the inner diameter of the ring-shaped first plate 2 is inserted into the outer diameter of the gap guide, and the first magnet is inserted via an adhesive. 1. Join on top.

On the first plate, a frame 5 press-formed with metal or the like in a funnel shape is fixed with tacks or the like.

By magnetizing N, S, for example, in the thickness direction of the first magnet 1 in the above-mentioned sub-assembly state,
The yoke 3 is magnetized to the S pole and the first plate 2 is magnetized to the N pole.

Next, a second magnet 6 made of a ring-shaped ferrite or the like serving as a cancel magnet having substantially the same diameter as the outer diameter φ _M of the first magnet 1, and an outer diameter φ of the second magnet 6 A disk-shaped or ring-shaped second plate 11 having a diameter φ _p sufficiently larger than _M is prepared.

The second plate 11 is made of a magnetic material having a high magnetic permeability. The sub-assembled magnetic circuit in which the second magnet 2 is bonded to the second plate 6 with an adhesive is applied to the second magnet 6 in the thickness direction of the second magnet 6 and in the same direction as the first magnet 1, for example, on the second plate 11 side. Is the N pole, and the magnet side is magnetized to the S pole.

Second magnet 6 reversely magnetized as described above
To the yoke 3 so that the yoke 3 has the same polarity, for example, the S pole.
To the bottom surface of the device via an adhesive.

Inner diameter of first plate 2 and center pole 3
a, the inner diameter of the voice coil bobbin 9 around which the voice coil 8 is wound is inserted into the outer diameter of the guide spacer inserted into the center pole 3a, and the outer diameter of the voice coil bobbin 9 is inserted into the magnetic gap 4 formed between the outer diameters of the voice coil bobbin 9. A voice including the voice coil bobbin 9 is joined by bonding the inner diameter of the corrugated concentric damper 14 inserted into the middle position of the voice coil bobbin 9 to the outer diameter of the voice coil bobbin 9 via an adhesive, and bonding the outer diameter to the outer circumference of the bottom of the frame 5. The coil 8 is pivotally attached to the frame 5 so as to be vertically swingable.

Further, the inner diameter of a diaphragm 15 having a cone-shaped fixed edge or free edge 16 is joined to the upper end of the voice coil bobbin 9, and the outer periphery of the edge 16 is joined to the largest opening of the frame 5 via a gasket 18. Then, by joining the upper opening of the voice coil bobbin 9 so as to cover it with a dome-shaped cap 17 for preventing dust from entering, the vibration system is pivotally attached to the frame 5 so as to be swingable.

The first and second magnets 1 having the above configuration
And the thickness of 6 when the T _1, the diameter of the first and second plates 2 and 11 and phi _P, the diameter difference when the diameter phi _M of the first and second magnet 1 and 6 2D are 2D =
It becomes a φ _P -φ _M. By selecting D at this time as D ≧ T ₁ , the magnetic flux density of the magnetic gap 4 can be increased by about 10%.

In FIG. 1, the first and second magnets 1 and 6
Of the diameter phi _M and the difference _{φ P -φ M = 2D / 2} = D between the diameter phi _P of the first and second plates 2 and 11, first and second
Table 1 shows the magnetic flux density of the magnetic gap 4 when the thickness T ₁ of the magnets 1 and 6 is compared with FIG. 1 and FIG. 10 of the conventional example.

[0025]

[Table 1]

According to the configuration of FIG. 1, the diameter φ _P of the first and second plates 2 and 11 is sufficiently larger than the diameter φ _M of the first and second magnets 1 and 6, and
And the interval between the second plates 2 and 11 T _T = 2T ₁ +
The spacing of the T ₂ also are taken sufficiently leakage magnetic flux phi _L1 and phi
_By reducing _L2 as shown in Table 1, the magnetic flux density in the magnetic gap 4 is increased by about 10%.

2 to 4 are substantially the same as those in FIG. 1. In the description of the present invention, corresponding parts are denoted by the same reference numerals, and redundant description will be omitted.

The speaker 10 of FIG. 2 has a shield cover 7 made of a cylindrical magnetic material or the like having high magnetic permeability between the outer circumferences of the first and second plates 2 and 11. Therefore, since the first and second plates 2 and 11 have the same polarity, the magnetic flux in the shield cover 7 repels each other, and the first and second magnets 1 and 6 Since the distance D to the south pole is sufficiently large, no leakage magnetic flux φ _L1 is generated as shown by a virtual line.

FIGS. 3 and 4 have substantially the same structure as FIG.
The shield cover 7 is made of a magnetic material having a high magnetic permeability and has a cylindrical shape with a bottom. The bottom of the shield cover 7 and the bottom of the second plate 11 are joined with an adhesive, and the cylindrical portion of the shield cover 7 is formed. It extends to the outer periphery of the first plate 2.

In FIG. 3, the extended cylindrical portion of the shield cover 7 is completely joined to the outer periphery of the first plate 2 as in FIG. 2, and in the case of FIG. A sufficiently wide gap G is provided on the outer periphery of one plate 2. (Even the conventional magnetic shield type shown in FIG. 10 has a gap or is about 0.5 mm.)

Further, in FIG. 3 and FIG.
1 is formed in a ring shape and is pierced in the center of the second plate 11
Diameter of the inner diameter φ_P1Of the inner diameter of the second magnet 6
Diameter φ _M1Take the yoke 3 and the second plate 1
Leakage magnetic flux φ between inner diameters between 1 _L2Is made to reduce
You.

FIGS. 5 to 8 show still another embodiment of the loudspeaker according to the present invention. FIG. 5 is shown in FIG. 1 and FIG.
7 corresponds to FIG. 3, and FIG. 8 corresponds to FIG. 4. Since the magnetic circuits are different from those of FIGS. 1 to 4, only the magnetic circuits of FIGS. 5 to 8 will be described below.

In FIGS. 5 to 8, the magnetic circuit used in the speaker of this embodiment is of a magnetic shield type. That is, the inner diameter of the ring-shaped second magnet 6, which constitutes a cancel magnet magnetized in the thickness direction, for example, N and S, is formed above the center pole 3a planted in the center of the disc-shaped yoke 3, and the inner diameter of the magnet guide 3b. And joined via an adhesive.

In this case, the diameter φ _Y of the disk portion of the yoke 3 is selected to be sufficiently larger than the diameter φ _{M of} the second magnet 6, and the thickness T ₁ of the second magnet 6 is also selected to be thick.

Further, a second plate 11 formed in a ring shape is joined to the upper surface of the second magnet 6 with an adhesive. In this case, a gap guide is inserted into the center pole 3a so that the inner diameter of the second plate 11 and the outer diameter of the center pole 3a become a predetermined dimensional gap of the magnetic gap 4.

The outer diameter of the second plate 11 is selected to be smaller than the outer diameter of the second magnet 6.

On the second plate 11, a ring-shaped first magnet 1 magnetized with, for example, S and N is bonded via an adhesive in a direction opposite to the thickness direction of the second magnet 6 serving as a main magnet. I do.

Next, a ring-shaped first plate 2 having substantially the same diameter as the outer diameter of the yoke 3 is joined to the upper surface of the first magnet 1 via an adhesive.

A frame 5 pressed with a funnel-shaped metal or the like is fixed on the upper side of the plate 2 by tacking or the like, and a vibration system similar to that shown in FIGS. .

The speaker 1 having the magnetic circuit having the above configuration
According to 0, the magnetic flux flows from the N pole of the second magnet 6 through the second plate 11 and the magnetic gap 4 to the S pole of the second magnet 6 from the yoke 3 via the center pole 3a. The first magnetic flux φ ₁ and the N pole of the first magnet 1 pass through the second pole 11 and the magnetic gap 4 through the center pole 3 a and the magnetic gap between the center poles 3 a and the first plate 2. And the magnetic flux φ ₂ flowing in the magnetic path to the S pole of the first magnet 1, the utilization efficiency of the conventional external magnet type in the magnetic gap 4 is reduced by the first and second magnets 1, 2. Compared to the case where the magnetomotive force is not used, which is about 1/3 of the total magnetomotive force, the magnetic flux density of the magnetic gap 4 is increased, the driving force of the diaphragm is almost doubled, and a magnetic shield type can be obtained. Have been.

The diameter φ _M of the first and second magnets 1 and 6 and the diameter φ of the first plate 2 and the yoke 3 in FIG.
It has a difference _{φ Y -φ M = 2D / 2} = D and the first and the same magnetic circuit and a thickness T ₁ and FIG. 1 and FIG. 1 of the second magnet 1 and 6 of the _Y, the first and second Table 2 shows the magnetic flux density of the magnetic gap 4 when compared with the speaker in which the diameter of the plate No. 2 is small.

[0042]

[Table 2]

According to the configuration of FIG. 5, the first plate 2
Diameter φ of yoke 3_YTo the first and second magnets 1 and
6 large enough compared to the diameter of 6 and the first plate
Spacing T between 2 and yoke 3_T= 2T₁+ T_TwoIs enough
Leakage flux φ _L1Reduce the magnetic air gap
The magnetic flux density in the part 4 is increased to 10%.

In the case of FIG. 6, the outer periphery of the first plate and the yoke of FIG. 5 is surrounded by the same cylindrical shield cover 7 between the first plate 2 and the yoke 3 as in FIG. 8
In the case of (1), the first plate 2 and the yoke are surrounded by the bottomed cylindrical shield cover 7 so as to abut or oppose each other as in FIGS.

According to the loudspeaker 10 having the configuration shown in FIGS. 6 and 7, not only the magnetic shield type configuration can be achieved, but also the magnetic flux density passing through the magnetic gap 4 can be further increased as compared with the case shown in FIG.

That is, in addition to the magnetic fluxes φ ₁ and φ ₂ described with reference to FIG.
Plate 11 → magnetic gap 4 → center pole 3a downward → yoke 3 → shield cover 7 → first plate 2 →
The magnetic flux φ ₃ passing through the magnetic path to the S pole of the first magnet 1 and the magnetic flux coming out of the N pole of the first magnet 1 → the second plate 11 → the magnetic gap 4 → upward on the center pole 3a → Magnetic gap between center pole 3a and first plate 2 →
First plate 2 → Shield cover 7 → Yoke 3 → Second
The magnetic flux in the magnetic gap 4 is further increased by the magnetic flux φ ₄ passing through the magnetic path of the S pole of the magnet 6.

In the configuration shown in FIG. 8, the gap G between the inner periphery of the cylindrical portion of the shield cover 7 and the first plate 2 is sufficiently large, so that the magnetic flux density in the magnetic gap 4 is almost the same as in FIG. It becomes possible to make it the type speaker 10.

FIG. 9 shows an ordinary box-shaped speaker box 21.
A speaker 23 having a duct opening 23a is provided in the baffle board 22 of the speaker box 21. A speaker sound emission hole 22a is formed in the baffle board 22, and the speaker 10 described in detail in FIG. 4 is fixed to the speaker sound emission hole 22a. Things.

According to the loudspeaker device having this configuration, the magnetomotive force in the magnetic gap 4 is increased only by increasing the size of the yoke or the first or second plate, so that a small loudspeaker capable of expanding the low range is provided. can get.

[0050]

According to the speaker and the speaker device of the present invention, the following effects can be obtained. (1) According to the present invention, the leakage magnetic flux on the outer periphery of the magnet can be reduced only by providing the second plate made of a magnetic material or the like having a diameter sufficiently larger than the second magnet below the second magnet constituting the cancel magnet. A speaker and a speaker device which can decrease and increase the magnetomotive force of the magnetic gap by 10% or more can be obtained. (2) According to the present invention, only by providing a yoke sufficiently larger than the diameter of the second magnet below the second magnet constituting the cancel magnet, the leakage magnetic flux on the outer periphery of the magnet is reduced, and the generation of the magnetic gap is generated. A speaker and a speaker device capable of increasing the magnetic force by 10% or more can be obtained.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing one embodiment of a speaker of the present invention.

FIG. 2 is a sectional view showing another embodiment of the speaker of the present invention.

FIG. 3 is a side sectional view (I) showing still another embodiment of the speaker of the present invention.

FIG. 4 is a side sectional view (II) showing still another embodiment of the speaker of the present invention.

FIG. 5 is a side sectional view (III) showing still another embodiment of the speaker of the present invention.

FIG. 6 is a side sectional view (IV) showing still another embodiment of the speaker of the present invention.

FIG. 7 is a side sectional view (V) showing still another embodiment of the speaker of the present invention.

FIG. 8 is a side sectional view (VI) showing still another embodiment of the speaker of the present invention.

FIG. 9 is a side sectional view showing one embodiment of the speaker device of the present invention.

FIG. 10 is a side sectional view of a conventional speaker.

[Explanation of symbols]

1,6 first and second magnets, 2,11 first and second plates, 3 yokes, 10 speakers

Continued on the front page (72) Inventor Ikuo Shinohara 6-35 Kita Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 5D012 BB03 BB04 BB05 BB09 EA03 FA08

Claims (4)

[Claims] 1. A speaker having a magnetic circuit using first and second magnets, wherein a plate made of a magnetic material having a diameter larger than the outer diameter of the first and second magnets is provided. A loudspeaker characterized by being disposed on an upper side and / or a lower side or at least one of them. 2. The speaker according to claim 1, wherein the lower plate is a yoke. 3. The loudspeaker according to claim 1, wherein a shield cover is provided so that an outer periphery of the lower plate and an outer periphery of the upper plate face or contact with each other. 4. A magnetic circuit having first and second magnets, wherein a plate made of a magnetic material having a larger diameter than the outer diameter of the first and second magnets is provided on the upper and lower sides of the first and second magnets. A loudspeaker device, wherein a loudspeaker provided on at least one of the loudspeakers is disposed in a loudspeaker box.