JP2002300695A - Speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that the conventional speaker needs to prevent a damper supporting a movable part from contacting to a magnetic field generator and hence takes a space between the damper and the field generator to result in the increase of the thickness. SOLUTION: A magnetic material-made movable yoke 29 is up and down movably supported with dampers 31, 32 and voice coils C1, C2 are provided inside the yoke 29. In a frame 22 a magnetic field generator 23 is secured inside the voice coils C1, C2. Thus the yoke 29 is movable up and down, together with the voice coils C1, C2, this having no need of leaving a space for oscillation between the yoke and the dampers, unlike the conventional one, and hence making the speaker thin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loudspeaker in which a magnetic drive means can be arranged in a thin space and a movable range in the amplitude direction of a diaphragm can be provided.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view showing a conventional speaker.

A speaker 1 shown in FIG. 3 has a frame 2 formed of an aluminum alloy or the like. The frame 2 has a cone portion 2A and a storage portion 2B provided on the bottom side thereof. A pedestal 2C protruding forward is formed at the bottom of the storage section 2B, and the magnetic field generating section 3 is provided on the pedestal 2C. The magnetic field generator 3 includes a cylindrical lower yoke 4, a magnet 5, and an upper yoke 6.
Are laminated.

A cylindrical outer yoke 7 is fixed to the inner peripheral surface of the storage section 2B, and a first magnetic gap G1 is formed at a portion where the outer peripheral surface of the lower yoke 4 and the inner peripheral surface of the outer yoke 7 face each other. ,
A second magnetic gap G2 is formed at a portion where the outer peripheral surface of the upper yoke 6 and the inner peripheral surface of the outer yoke 7 face each other.

[0005] A front end 12 a of a conical diaphragm 12 is supported via a deformable member 11 on a flange 2 D at the front edge of the cone 2 A of the frame 2. Further, the base end 12 b of the diaphragm 12 is bonded to a connection portion 9 c on the upper outer peripheral surface of the cylindrical bobbin 9. Further, an outer peripheral edge of a bellows-shaped damper member 10 is fixed to the step portion 2a of the cone portion 2A, and a center portion of the damper member 10 is bonded to an upper end of the bobbin 9 at the connection portion 9c. . The bobbin 9 and the diaphragm 12 are supported by the damper member 10 so as to be able to vibrate vertically in the drawing.

[0006] On the outer peripheral surface of the bobbin 9, there are provided two voice coils 9a and 9b wound by conductors covered with an insulating material, and the voice coil 9a is inserted into the first magnetic gap G1. Then, the voice coil 9b is inserted in the second magnetic gap G2.

In the speaker 1, the voice coils 9a, 9a located in the magnetic gaps G1, G2 of the magnetic field generator 3 are provided.
When an audio signal is given to b, the bobbin 9 and the diaphragm 12 are vibrated by an electromagnetic force generated between the current of the audio signal and the magnetic field in each of the magnetic gaps G1 and G2 to generate sound.

[0008]

However, in the conventional speaker 1, the damper member 10 is connected to the outer periphery of the bobbin 9 at the connecting portion 9c, and the voice coils 9a and 9b provided on the bobbin 9 are driven by a magnetic field. Because of the structure inserted between the generating part 3 and the outer yoke 7, the connecting part 9c
It is necessary to provide an allowance L for the bobbin 9 to vibrate in the vertical direction between the upper yoke 7 and the upper end surface 7a of the outer yoke 7.

If the clearance L is small, the connecting portion 9c of the bobbin 9 hits the upper end of the outer yoke 7 when the diaphragm 12 and the bobbin 9 vibrate with a large amplitude, so that an impact sound and chattering sound are generated. Become. Therefore, the margin L needs to be set sufficiently long, and the whole speaker 1 has a vertically thick shape.

In particular, in the speaker 1 which needs to generate a large output in a low frequency range, a large amplitude vibration may be temporarily given to the bobbin 9 by an audio signal given to the voice coils 9a and 9b. . Therefore, in this type of speaker 1, it is necessary to secure the margin L sufficiently long, and the thickness of the speaker is inevitably increased.

An object of the present invention is to solve the above-mentioned conventional problems, and it is an object of the present invention to provide a speaker capable of increasing the amplitude of a diaphragm and a movable portion even if the overall thickness is reduced.

[0012]

SUMMARY OF THE INVENTION The present invention comprises a frame,
In a speaker provided with a vibrating body supported by the frame and magnetic driving means for driving the vibrating body, in the magnetic driving means, a magnetic field generating unit is fixed to the frame side, and together with the vibrating body A movable yoke and a movable coil formed of a magnetic material are provided in the movable portion that vibrates, and the movable coil is located between the magnetic field generating portion and the movable yoke with a gap provided between the magnetic field generating portion and the movable yoke. It is characterized by being opposed.

In the present invention, since the movable coil and the movable yoke vibrate together with the vibrating body, even if the diaphragm and the movable yoke vibrate with a large amplitude, the damper member for supporting the movable portion, the movable yoke and the movable yoke are provided. Can not be hit. Therefore, the movable margin L as in the conventional example shown in FIG.
It is no longer necessary to provide a speaker, and the speaker can be made thinner, the amplitude of the movable portion can be increased, and the speaker can be configured as a large output.

The vibrating body has a conical shape with a large diameter at the front end facing the sound generation direction and a small diameter at the base end facing the magnetic drive means. The movable yoke is connected to the base end of the vibrating body. It is preferable that a damper member is provided between the movable yoke and the frame so as to support the movable yoke so as to vibrate.

Further, in the magnetic driving means, the magnetic field generating section is fixed to the center side, and outside the magnetic field generating section,
The cylindrical movable yoke and the movable coil installed on an inner peripheral surface of the movable yoke are provided, and the movable yoke is oscillated between the outer peripheral surface of the movable yoke and the frame. It can be configured as provided with a damper member.

As described above, by directly connecting the movable yoke and the vibrator and directly connecting the movable yoke and the damper member, the positions of the vibrator and the movable coil can be made closer to each other, and furthermore, the speaker Can be made thin.

It is preferable that the upper and lower portions of the movable yoke have a shape in which the outer peripheral surface gradually faces toward the center toward the end.

Further, when the frame is provided with a guide member for movably guiding the movable yoke in the axial direction thereof, the gap between the movable coil and the magnetic field generator provided on the fixed side is optimized. Can be set to

For example, the magnetic field generating section is formed by stacking a lower yoke, a magnet and an upper yoke. The magnetic field generating section is provided between the lower yoke and the movable yoke and between the upper yoke and the movable yoke. This is where the moving coil is located. However, the magnetic field generating unit may be formed by only a magnet, and the movable coil may be formed by one coil facing the magnet.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of a speaker according to the present invention, and FIG. 2 is a perspective view showing a movable yoke, a first damper member and a guide member.

The frame 22 of the speaker 20 shown in FIG.
Is a cup-shaped storage section 22A provided on the lower side,
A cone portion 22B extending forward from the upper opening end of the storage portion 22A. The storage section 22A and the cone section 22B may be integrally formed by a mold, or may be formed separately and assembled by screwing or the like. In this embodiment, the storage portion 22A and the cone portion 22B are formed by die-casting using an aluminum alloy or the like.

A magnetic driving means is provided inside the storage section 22A. This magnetic drive means is provided with a magnetic field generator 23 on the fixed part side, and voice coils C1 and C2 as movable coils and a movable yoke 29 on the movable part.

A pedestal 22C which protrudes forward is formed at the center of the bottom of the storage portion 22A.
The magnetic field generator 23 is provided on 2C. The magnetic field generator 23 includes a lower yoke 24 and a magnet 2 from below.
5 and the upper yoke 26 are superimposed, each of which has a columnar shape. And the magnet 2
5 is magnetized so that the upper surface and the lower surface have different magnetic poles. The lower yoke 24, the magnet 25, and the upper yoke 26 are integrally fixed by the magnetic attraction of the magnet 25 and the adhesive force of the adhesive. The lower yoke 24 is fixed to the upper surface of the pedestal 22C by bonding or screwing.

As a movable portion of the magnetic drive means, a thin cylindrical movable yoke 29 and voice coils C1 and C2 serving as movable coils provided on the inner peripheral surface of the movable yoke 29.
Is provided.

The movable yoke 29 is made of Fe, Ni or C
It is formed of a soft magnetic material having a high magnetic permeability such as o and a high saturation magnetic flux density. As shown in FIGS. 1 and 2, at the upper and lower portions of the movable yoke 29, the outer peripheral surface thereof has a tapered surface 2 that gradually faces toward the center toward the upper and lower ends.
9a and 29b are formed.

The voice coils C1 and C2 are formed by winding a conductive wire covered with an insulating material, or by a cylindrical flexible printed board having a thin-film coil pattern. The voice coils C1 and C2 are spaced apart in the axial direction of the movable yoke 29,
9 is adhered and fixed to the inner surface of the substrate 9. The winding directions of the voice coil C1 and the voice coil C2 are opposite to each other, and the voice coil C1 and the voice coil C2 are connected in series.

A step 22E is formed circumferentially on the inner peripheral surface of the storage section 22A of the frame 22, and the step 22E is formed.
, A cylindrical fixing member 30 is fitted. An outer peripheral portion of a first damper member 31 is fixed to a lower end surface 30a of the fixing member 30, and an outer peripheral portion of a second damper member 32 is fixed to an upper end surface 30b of the fixing member 30.

The first damper member 31 and the second damper member 32 are formed of a paper material, a paper material whose surface is coated with a resin, a thin resin plate, or the like.
The damper members 31 and 32 are corrugated, and concavo-convex portions that repeat in the radial direction are formed concentrically.

The inner edge 31 of the first damper member 31
a is a lower connecting portion 29 of the outer peripheral surface of the movable yoke 29;
c is bonded with an adhesive. The inner edge 32a of the second damper member 32 is bonded to the upper connecting portion 29d of the outer peripheral surface of the movable yoke 29 with an adhesive.

The movable yoke 29 is supported by the first and second damper members 31 and 32 and is positioned so as to be concentric with the outer peripheral surface of the magnetic field generating section 23.
The voice coil C1 faces the outer peripheral surface of the lower yoke 24 via a magnetic gap G1, and the voice coil C2 faces the outer peripheral surface of the upper yoke 26 via a magnetic gap G2.

A guide member 27 made of synthetic resin is provided around the movable yoke 29. As shown in FIG. 2, the guide member 27 is provided with a plurality of guide pieces 27b extending vertically on a ring-shaped base 27a. The center hole 27c of the base 27a is
The guide pieces 27b are positioned so as to be arranged concentrically with the center of the storage portion 22A by being fitted to the outer peripheral portion of a pedestal 22C that is raised at the bottom of the storage portion 22A. And
The base 27a is fixed to the upper surface of the bottom 22a of the storage section 22A by fixing means such as bonding or screwing.

As shown in FIG. 2, insertion holes 31c into which the respective guide pieces 27b can be inserted with a margin are formed in the inner peripheral portion of the first damper member 31, respectively. Each guide piece 27b extending from the base 27a is inserted into each of the insertion holes 31c, and faces the outer peripheral surface of the movable yoke 29 via a minute gap. When the movable yoke 29 vibrates up and down, the guide piece 27b prevents the movable yoke 29 from touching in the left-right direction.

In the magnetic drive means of the speaker 20 shown in FIG. 1, the magnetic flux from the N pole of the magnet 25
4 from the side of the magnetic gap G1 and voice coil C1
And enters the movable yoke 29. Further, the magnetic flux enters the upper yoke 26 from the upper inner peripheral surface of the movable yoke 29 through the voice coil C2 and the magnetic gap G2.

Here, tapered surfaces 29a and 29b are formed at the upper and lower ends of the outer peripheral surface of the movable yoke 29, and these tapered surfaces 29a and 29b are used for a circular path of magnetic flux passing through the movable yoke 29. Since the tapered surfaces 29a and 29b are provided along the shape, the weight of the movable yoke 29 can be reduced without lowering the efficiency of magnetic flux passing through the movable yoke 29.

At the upper end of the movable yoke 29, a rear end 34a of a cone-shaped vibration plate (vibration body) 34 is adhered and fixed. The front end of the diaphragm 34 has an annular edge 33.
Is supported by a flange portion 22D formed at the front end of the cone portion 22B of the frame 22 so as to be able to vibrate. Reference numeral 35 denotes a dome member that closes the central opening of the diaphragm 34.

When voice signals of opposite directions are applied to the voice coils C1 and C2, an electromagnetic driving force according to Fleming's left-hand rule is applied to the voice coils C1 and C2 to which the magnetic flux from the magnetic field generating unit 23 interlinks. Act, the movable yoke 29 is vibrated in the axial direction, and the diaphragm 34 vibrates together with the movable yoke 29 to generate a sound corresponding to the audio signal.

At this time, since the movable yoke 29 is held up and down at the center of the first damper member 31 and the second damper member 32, the movable yoke 29 is restrained so as not to swing right and left. It will vibrate. Therefore,
Magnetic gap G between lower yoke 24 and voice coil
1, and the magnetic gap G2 between the upper yoke 26 and the voice coil C2 is always uniform all around the magnetic field generator 23. Accordingly, the magnetic drive efficiency is improved, and a good sound without sound distortion can be generated.

Further, the outer peripheral surface of the movable yoke 29 is regulated by the guide piece 27b, and the guide piece 27b regulates the movable yoke 29 from swinging largely right and left. Therefore, when a large external acceleration is applied to the movable yoke 29 in the left-right direction due to an external impact or the like,
The movable yoke 29 can be prevented from oscillating in the left-right direction, and the deformation and breakage of the damper members 31 and 32 can be prevented. That is, the guide piece 27b functions as a guide portion when the movable yoke 29 is vibrated in the axial direction, and also functions as a regulating portion that regulates the movable yoke 29 from swinging in a direction crossing the axis.

The movable yoke 29 has a voice coil C
Since it vibrates up and down integrally with C1 and C2, there is no need to provide a margin L between the yoke and the damper member as in the conventional example shown in FIG. In the structure shown in FIG. 1, a margin La for vibration is provided between the lower end of the movable yoke 29 and the bottom 22a of the storage portion 22A (the base 27a of the guide member 27). If a margin Lb for vibration is provided between the movable yoke 29 and the dome member 35, the movable yoke 29 can be moved within the range of the margins La and Lb.
Can be greatly vibrated up and down. Therefore, the overall structure can be reduced in thickness, the amplitude of the diaphragm 34 can be increased, and a high-output speaker can be configured. In particular, a large output can be realized in a low frequency range.

In particular, the movable yoke 29 has the damper member 3
1 and 32 and the front end 34a of the diaphragm 34 are directly connected to each other.
Can be arranged close to each other up and down, and the thickness dimension of the top and bottom can be made extremely small.

In this embodiment, the magnetic field generator 2
3, a lower yoke 24 and an upper yoke 26 are provided.
The two voice coils C1 and C2 face the lower yoke 24 and the upper yoke 26, but a magnet is provided in the magnetic field generating portion in the radial direction, and one magnet opposed to the outer peripheral surface of the magnet is provided. The structure provided with the voice coil may be sufficient.

[0043]

As described above, according to the present invention, even if the whole speaker is made thin, the amplitude of the movable part and the diaphragm can be increased, and for example, a large output in a low frequency range can be obtained. It is.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a speaker according to the present invention;

2 is a perspective view showing a movable yoke, a first damper member, and a guide member of the speaker shown in FIG. 1,

FIG. 3 is a sectional view showing a conventional speaker.

[Explanation of symbols]

 Reference Signs List 20 speaker 22 frame 22A storage section 22B cone section 24 lower yoke 25 magnet 26 upper yoke 27 guide member 29 movable yoke 31 first damper member 32 second damper member 34 diaphragm (vibrator) C1 voice coil (movable coil) C2 Voice coil (moving coil) G1 Magnetic gap G2 Magnetic gap

Claims (7)

[Claims] 1. A speaker provided with a frame, a vibrating body supported by the frame, and a magnetic driving unit for driving the vibrating body, wherein the magnetic driving unit has a magnetic field generating unit fixed to the frame side. A movable yoke and a movable coil formed of a magnetic material are provided on a movable portion that vibrates together with the vibrator, and the movable coil is located between the magnetic field generator and the movable yoke. A loudspeaker characterized in that the loudspeaker faces a magnetic field generating unit via a gap. 2. The vibrating body has a conical shape having a large diameter at a front end facing a sound generation direction and a small diameter at a base end facing a magnetic driving means, and the movable yoke is connected to a base end of the vibrating body. The speaker according to claim 1, wherein 3. The loudspeaker according to claim 1, wherein a damper member is provided between said movable yoke and said frame so as to support said movable yoke so as to be able to vibrate. 4. The magnetic drive unit, wherein the magnetic field generating unit is fixed to a center side, and the movable yoke is provided outside the magnetic field generating unit and on a cylindrical inner surface of the movable yoke. The speaker according to claim 1, wherein a coil is provided, and a damper member that supports the movable yoke so as to vibrate is provided between an outer peripheral surface of the movable yoke and the frame. 5. The loudspeaker according to claim 4, wherein the upper and lower portions of the movable yoke have a shape in which an outer peripheral surface gradually faces toward a center toward an end. 6. The speaker according to claim 1, wherein the frame is provided with a guide member that guides the movable yoke movably in an axial direction thereof. 7. The magnetic field generator includes a lower yoke, a magnet, and an upper yoke which are overlapped with each other. The magnetic field generator is provided between the lower yoke and the movable yoke and between the upper yoke and the movable yoke. The speaker according to any one of claims 1 to 6, wherein the movable coil is located.