JP2573966Y2 - Speaker - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention uses one magnet and magnetic gaps are formed at two places in a magnetic path, and the two magnetic gaps are symmetrically arranged above and below a single bobbin. The present invention relates to an improvement of a magnetic circuit portion in a speaker in which voice coils wound separately are arranged.

[0002]

2. Description of the Related Art Hitherto, the impedance of a voice coil in a high frequency range has been suppressed to prevent a decrease in the efficiency of a treble portion, and to cancel the nonlinearity of a drive system to suppress distortion of reproduced sound. In order to obtain a left and right sum signal reproduction sound in a super low frequency range in a stereo by a simple means, as shown in FIG. 5 and described in Japanese Utility Model Laid-Open No. 63-23896, Using the magnet 23, the magnet 23
The upper plate 21 and the lower plate 22 fixed to the upper and lower surfaces respectively form magnetic gaps in the upper and lower portions of the center pole 24, and the two magnetic gaps are symmetrical to the upper and lower portions of the single bobbin 27. Voice coil 28 wound around
The speaker which arranges each 29 is put into practical use.
In FIG. 5, 31 is a diaphragm, 32 is a frame for holding the diaphragm and the like, 33 is an edge of the diaphragm, and 35 is a damper.

[0003]

A conventional loudspeaker having such a structure is composed of an upper plate 21 and a lower plate 22.
In order to hold the center pole and the center pole 24 concentrically, a yoke 30 fixed across both the lower plate 22 and the center pole 24 at the bottom of the magnetic circuit is used. There is a problem to be solved that the part is heavy and large.

Accordingly, the present invention has solved the above-mentioned disadvantages of the prior art, and has reduced the thickness after assembly by directly supporting a center pole by a joint from a magnet sandwiched between upper and lower plates. An object of the present invention is to provide a speaker having a plurality of voice coils.

[0005]

The loudspeaker according to the present invention for achieving the above object will be described with reference to FIGS. 1 to 3 showing an embodiment. Magnetic gaps 5 and 6 are formed symmetrically above and below the center pole 4 by the upper plate 1 and the lower plate 2 fixed to the upper and lower surfaces, and the upper and lower magnetic gaps 5 and 6 have a diaphragm 15 at one end. A symmetrically wound voice coil 8, 9 disposed above and below a single bobbin 7 to which the bobbin 7 is coupled.
Slits or windows 10 are formed at a plurality of positions between the voice coils 8 and 9, and a non-centering hole for holding the center pole 4 concentrically with respect to the magnet 3, the upper plate 1 and the lower plate 2. The speaker is characterized in that a plurality of joints 11 made of a magnetic material penetrate the slit 10 and are arranged so as to straddle the inner peripheral surface of the magnet 3 and the outer peripheral surface of the center pole 4.

FIG. 4 shows a sectional view of a second device according to the present invention, in which an upper pole 12 fixed to the upper and lower surfaces of a magnet 3 is provided.
A ring-shaped yoke 14 is arranged outside the lower pole 13 and the inner peripheral surface of the yoke 14 and the outer surfaces of the upper pole 12 and the lower pole 13 symmetrically define the magnetic gaps 5 and 6 above and below the yoke 14. The voice coils 8, 9 symmetrically wound around the upper and lower portions of a single bobbin 7 having a diaphragm 15 fixed at one end to the upper and lower magnetic gaps 5, 6 are formed. In the speaker, slits or windows 10 are formed at a plurality of locations in the bobbin 7 between the voice coils 8 and 9, and a yoke 14 is concentric with the magnet 3, the upper pole 12 and the lower pole 13. A plurality of joints 11 made of a non-magnetic material for holding the magnets are arranged so as to penetrate the slit 10 and straddle the outer peripheral surface of the magnet 3 and the inner peripheral surface of the yoke 14. A speaker characterized by.

Further, according to the first and second inventions, the speaker is characterized in that the joint 11 is made of a conductive material and has a vertically symmetric shape.

[0008]

In the loudspeaker having such a structure, a joint 11 for holding the upper and lower plates 1 and 2 and the center pole 4 concentrically is present inside the magnetic circuit, and on the back of the magnetic circuit. Since only a thin dust-proof cloth is present and the support member such as the yoke 30 of the conventional magnetic circuit does not protrude, it is possible to provide a very thin and compact magnetic circuit speaker having two sets of driving parts. .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The first embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view of the loudspeaker of the embodiment in two directions, and FIG. Each section is shown in FIG.
In the directions of arrows OY and OX indicated in FIG.

In the magnetic circuit, an upper plate 1 and a lower plate 2 are fixed to the upper and lower surfaces of a ring-shaped magnet 3, and a plurality of center poles 4 made of a non-magnetic material (four in this embodiment). The magnetic gaps 5 and 6 are formed symmetrically above and below the center pole 4 by being held from the inner peripheral surface of the magnet 3 so as to be concentric with the upper plate 1 and the lower plate 2 by the joint 11.

In the two magnetic air gaps 5, 6, voice coils 8, 9 symmetrically wound around the upper and lower portions of a single bobbin 7 are arranged, as shown in detail in FIG. In addition, slits or windows 10 are formed at a plurality of positions in a portion between the voice coils 8 and 9 of the bobbin 7 so that the joint 11
Is arranged between the inner peripheral surface of the magnet 3 and the outer peripheral surface of the center pole 4 through the window 10, so that the movement of the voice coil during the operation of the speaker is not hindered.

The magnetic circuit is mounted on the bottom of a frame 16 and a diaphragm 15 connected to the bobbin 7 has an edge 17 inside the frame 16 like a conventional speaker.
And a damper 18 so as to be able to vibrate.

A dust-proof cloth 19 is adhered to the back surface of the magnetic circuit to prevent dust from entering the magnetic gap. In the case of a short voice coil in which the winding width of the voice coils 8 and 9 is shorter than the thickness of the upper and lower plates as in the present embodiment, the dustproof cloth 19 is directly adhered to the lower plate as described above. When a long voice coil is used, the dustproof cloth 19 is arranged at a distance equal to the sum of the protrusion amount of the voice coil and the dimension corresponding to the maximum amplitude of the speaker, for example, separated from the back surface of the magnetic circuit using a spacer or the like. It is natural that we must do it.

FIG. 3 shows a modification of the loudspeaker according to the present invention. The joint 11 is made of a non-magnetic material having conductivity, the cross section of the loudspeaker is symmetrical in the vertical direction. Ring 20 made of non-magnetic material having
Are arranged, the joint 11 is radially connected to the ring 20 to be integrated, and the joint is used as a short ring for suppressing current distortion. In such a variant, not only the magnetic gap but also the joint 11
In order to make the cross-sectional shape symmetrical in the vertical direction, it is necessary to make the eddy current generated in the joint 11 and the action and effect of the eddy current on the voice coil equally symmetrical in each of the upper and lower driving units. Because.

As another form of the above-mentioned modified example, a shallow ring groove is formed in a side surface portion of the center pole 4 excluding a portion corresponding to a magnetic gap, and a conductive non-magnetic ring is inserted into the groove. (Not shown).

Although the magnetic circuit of the above-described embodiment is of the outer magnet type, the configuration of the present invention can be adopted even for an inner magnet type magnetic circuit. FIG. 4 shows an embodiment of the second invention of the present application, in which an upper pole 12 and a lower pole 13 are fixed to the upper and lower surfaces of the magnet 3, and the upper pole 12 and the lower pole 13 are fixed.
A yoke 14 having a U-shaped cross section and a ring shape is disposed on the outer side of the upper pole 12.
The magnetic gaps 5 and 6 are formed symmetrically above and below the yoke 14 by the outer surface of the lower pole 13 and the lower pole 13.

Thereafter, as in the first invention, voice coils 8, 9 symmetrically wound around the upper and lower portions of a single bobbin 7 having a diaphragm 15 fixed at one end to upper and lower magnetic air gaps 5, 6 respectively.
, The voice coil 8 of the bobbin 7,
9, a plurality of slits or windows 10 are formed at a plurality of locations, and a plurality of nonmagnetic materials for holding the yoke 14 concentrically with respect to the magnet 3, the upper pole 12, and the lower pole 13. A joint 11 penetrates the slit 10 and is disposed so as to straddle the outer peripheral surface of the magnet 3 and the inner peripheral surface of the yoke 14. The structure for holding the diaphragm 15 inside the frame 16 is the same as in the first invention.

The magnetic circuit of each of the above embodiments is divided into an inner peripheral part and an outer peripheral part with a cylindrical surface including a magnetic gap as a boundary, preliminarily processed, and after fitting a voice coil bobbin, If the joint 11 is attached to a center pole, a yoke, and a magnet with a small screw or an adhesive, it can be easily assembled.

As described above, the speaker according to the present invention has been described in detail based on the embodiment which is considered to be representative. However, the embodiment of the speaker according to the present invention is not limited to the structure of the above-described embodiment. The present invention can be appropriately modified and implemented as long as it has the constituent features described in the claims for utility model registration, exhibits the effects of the present invention, and has the effects described below.

[0020]

[Effect] The speaker according to the present invention has the following effects.

(1) As a loudspeaker having a drive unit at two locations on a single voice coil bobbin, it suppresses the impedance rise of the voice coil in the high frequency range, thereby preventing the efficiency of the treble part from lowering and preventing the drive system from being inefficient. The distortion of the reproduced sound can be suppressed by canceling the linearity. Therefore, a reproduced sound having excellent frequency characteristics and a low distortion can be obtained.

(2) Left and right sum signal reproduced sounds in a super low frequency range in a stereo can be obtained by simple means.

(3) Since the joint for supporting the center pole or yoke and the magnet concentrically is mounted inside the magnetic circuit, the size of the magnetic circuit is reduced.

(4) By using the assembling buhin (joint) as a short ring, high quality sound quality can be expected without requiring special parts for improving sound quality.

(5) The same magnetic circuit can support both a high-quality speaker and an LR-integrated speaker.

(6) In the case of a speaker provided with two coils on the same bobbin, a change in magnetic flux density due to the position of the coil can be canceled due to the vertical symmetry of the magnetic circuit and the vertical symmetry of the joint. Therefore, non-linear distortion is reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view in two directions of a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of a main part, illustrating a relationship between a center pole, a voice coil bobbin, and a joint, and showing cutting directions in FIGS. 1, 3, and 4;

FIG. 3 is a sectional view in two directions of a modification of the first embodiment;

FIG. 4 is a sectional view in two directions of the second invention.

FIG. 5 is a cross-sectional view of a conventional magnetic circuit unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper plate 2 Lower plate 3 Magnet 4 Center pole 5 Magnetic gap 6 Magnetic gap 7 Bobbin 8 Voice coil 9 Voice coil 10 Slit or window 11 Joint 12 Upper pole 13 Lower pole 14 Yoke 15 Vibration plate 16 Frame 17 Edge 18 Damper 19 Dustproof Cloth 20 Ring

Claims (3)

(57) [Scope of request for utility model registration] An upper plate (1) and a lower plate (2) fixed to an upper surface and a lower surface of a ring-shaped magnet (3) symmetrically above and below a center pole (4) by magnetic gaps (5). (6) is formed and symmetrically wound around the upper and lower portions of a single bobbin (7) having a diaphragm (15) fixed at one end to the upper and lower magnetic air gaps (5) and (6). In the speaker having the voice coils (8) and (9) arranged therein, slits or windows (10) are provided at a plurality of locations on the bobbin (7) between the voice coils (8) and (9). ), And a plurality of joints (11) made of a non-magnetic material for holding the center pole (4) concentrically with respect to the magnet (3), the upper plate (1) and the lower plate (2). ) Passes through said slit or window (10) The speaker is disposed so as to extend over the inner peripheral surface of the magnet (3) and the outer peripheral surface of the center pole (4). 2. A ring-shaped yoke (14) is arranged outside the upper pole (12) and the lower pole (13) fixed to the upper and lower surfaces of the magnet (3). Magnetic gaps (5) and (6) are formed symmetrically above and below the yoke (14) by the peripheral surface and the outer surfaces of the upper pole (12) and the lower pole (13).
The diaphragm (1) is provided at one end in the upper and lower magnetic gaps (5) and (6).
5) A speaker in which voice coils (8) and (9) wound symmetrically around a single bobbin (7) to which a bobbin (7) is fixed are arranged. Slits or windows (10) are formed at a plurality of locations between the voice coils (8) and (9), and a magnet (3), an upper pole (12), and a lower pole (1) are formed.
A plurality of joints (11) made of a non-magnetic material for holding the yoke (14) concentrically with respect to the slit (3) penetrate the slit or window (10).
The speaker is disposed so as to straddle the outer peripheral surface of the first member and the inner peripheral surface of the yoke (14). 3. The loudspeaker according to claim 1, wherein the joint is made of a non-magnetic conductor and has a vertically symmetrical shape.