JPH08317489A - Speaker device - Google Patents

Abstract

PURPOSE: To provide the speaker device of a magnetic shielding type for not using a cancel magnet. CONSTITUTION: Normal speakers which are not the magnetic shielding type are attached back to back on the mutually opposing side plates 36 of a thin speaker box 35, the magnet 13 of one of the speakers functions as cancel magnet to the magnet 13 of the other speaker and the magnets 13 of the pair of speakers mutually cancel leakage magnetic fluxes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker device, and more particularly to a speaker device comprising a plurality of speakers in which magnetic flux is prevented from leaking from a magnetic circuit to the outside.

[0002]

2. Description of the Related Art A widely used dynamic speaker is a magnet, a yoke, a center pole,
A magnetic circuit is formed by the plate, a voice coil is arranged in the gap between the center pole and the plate, and a signal current is passed through the voice coil to vibrate the diaphragm to which the voice coil is attached. ing.

Such a speaker is provided with a magnet to form a magnetic circuit as described above, and the magnetic flux generated by this magnet passes through the gap between the center pole and the plate. However, some of the magnetic flux leaks and diverges toward the outside.

In order to prevent such leakage magnetic flux, a magnetic shield type speaker as shown in FIG. 12 is used.
This speaker includes a yoke 1, a main magnet 2 and a plate 3.
To form a magnetic circuit, the voice coil 4 is arranged in the gap between the plate 3 of this magnetic circuit and the center pole of the yoke 1, and the diaphragm 5 is moved by passing a signal current through the voice coil 4. I try to make it vibrate.

A cancel magnet 6 is attached to the lower surface of the plate 1, and the cancel magnet 6 is magnetized in the direction opposite to that of the main magnet 2. To cancel each other.

In addition to the above-mentioned structure, the magnetic shield type speaker shown in FIG. 13 has a shield shield 7 made of iron so as to cover the outside of the magnetic circuit having the cancel magnet 6 attached to the bottom thereof to enhance the magnetic shield effect.

[0007]

As described above, in the conventional magnetically shielded speaker, the cancel magnet 6 magnetized in the opposite direction to the main magnet 2 is attached to the rear side of the main magnet 2, and the cancel magnet 6 is used. The leakage flux of the main magnet 2 is canceled. Furthermore, FIG.
As shown in FIG. 3, an iron shield cover 7 is attached so as to cover the main magnet 2 and the cancel magnet 6 to enhance the magnetic shield effect.

According to this structure, the cancel magnet 6 and the shield cover 7 are required, which increases the size of the speaker in the axial direction. Therefore, there is a problem that a flat speaker cannot be provided. Further, there is a problem that the cost of the speaker is increased by adding the cancel magnet 6 or the shield cover 7.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a speaker device capable of producing a magnetic shielding effect without adding a cancel magglut.

[0010]

The present invention comprises a pair of loudspeakers, which are arranged back to back so that the back sides of the respective magnetic circuits are in contact with or close to each other, and the magnets of the magnetic circuits of the respective loudspeakers are of the other type. The present invention relates to a speaker device that functions as a magnetic shield magnet for a magnet of a magnetic circuit of a speaker.

If shield rings are attached to the outer peripheral portions of the pair of speakers and the pair of speakers are arranged back-to-back with each other, the tip portions of the shield rings may be in contact with or close to each other. Also, a single shield ring common to the pair of speakers may be fitted to the outer peripheral portions of the magnetic circuits of the pair of speakers arranged back to back.

The pair of speakers may each be provided with a cup-shaped shield cover, and the bottom plate portions of these shield covers may be attached by being sandwiched between a magnet and a frame constituting a magnetic circuit. Alternatively, each of the pair of speakers may include a plate having a cup shape, and the cylindrical portions of these plates may form a shield cover.

The pair of speakers arranged back to back are mounted outward in the openings of the opposite side plates of the speaker box facing each other, and the reflector is provided obliquely to the pair of side plates. Good. A pair of speakers placed back to back in the speaker box may constitute a left channel speaker and a right channel speaker.

[0014]

Since the magnets of the magnetic circuit of the pair of speakers, which are arranged back to back, function as magnetism-shielding magnets for the magnets of the magnetic circuit of the other speaker, the leakage magnetic fluxes from the magnets of the pair of speakers are mutually different. Canceled.

[0015]

FIG. 1 shows the structure of a speaker used in a speaker device according to an embodiment of the present invention. The speaker has a frame 10 made of a rigid body. The magnetic circuit 11 is attached to the bottom of the frame 10. The magnetic circuit 11 includes a plate 12, and the plate 12 is fixed to the bottom of the frame 10. A ring-shaped magnet 13 is attached to the lower side of the plate 12, and the magnet 1
The bottom surface of 3 is received by the yoke 14. A center pole 15 is provided at the center of the yoke 14 so as to project upward.

A portion between the outer peripheral portion of the center pole 15 and the inner peripheral portion of the center opening of the plate 12 constitutes a gap, and the voice coil 18 is arranged in this gap. The bobbin 19 of the voice coil 18 has a tubular shape and extends upward, and a diaphragm 20 made of cone paper is fixed to the tip side of the bobbin 19. The outer peripheral portion of the diaphragm 20 is fixed to the inner peripheral surface of the frame 20 on the front end side by a fixing ring 21. Further, a cap 22 is attached to a central portion of the diaphragm 20 and a connecting portion with the bobbin 19. Further, the bobbin 19 connected to the diaphragm 23 is connected to the bottom side of the frame 20 via the damper 23.

The lead wire of the voice coil 18 is a tinsel wire 28.
And the tinsel wire 28 is connected to the frame 10.
It is adapted to be connected to the terminal 30 of the terminal plate 29 mounted on the outer peripheral surface of the. A signal current is externally supplied to the voice coil 18 through the terminal 30.

Next, a method of assembling such a speaker will be described. An adhesive is applied to the upper surface of the yoke 14 that constitutes the magnetic circuit 11, and the magnet 13 is placed. Then, an adhesive is applied to the upper surface of the magnet 13 to plate 1
Place 2. At this time, a gap guide is inserted into the gap between the outer peripheral portion of the center pole 15 and the inner peripheral portion of the plate 12 so that the outer peripheral portion of the center pole 15 and the inner peripheral portion of the plate 12 are concentric.

The frame 10 may be attached to the plate 12 in advance by means such as caulking, or it may be attached by mounting it on the magnetic circuit 11 after the magnetic circuit 11 is completed. Center pole 1 after the adhesive has dried
The body portion is completed by removing the gap guide between 5 and plate 12.

The inner peripheral portion of the next voice coil 18 and the outer peripheral portion of the center pole 15 are concentric, and a voice coil spacer for positioning the voice coil 18 is inserted into the voice coil 18 and fitted to the center pole 15. To combine.

Thereafter, the outer peripheral portion of the damper 23 is attached to the inner bottom portion of the frame 10, and the inner peripheral portion of the damper 23 is bonded to the outer peripheral surface of the bobbin 19 around which the voice coil 18 is wound. . Further, the outer periphery of the edge-attached cone paper 20 is fixed to the inner peripheral surface on the front end side of the frame 10 by a fixing ring 21, and the diaphragm 20
The inner peripheral side of the is bonded to the tip of the bobbin 19. Then, after the adhesive has dried, the voice coil spacer is removed and the cap 22 is bonded to the central portion of the diaphragm 20.

The other end of the tinsel wire 28 connected to the lead wire of the voice coil 18 is soldered to the input terminal 30. Finally, the magnet 13 is magnetized so that the top and bottom have opposite polarities as shown in FIG. 1 to complete the speaker.

When a signal current is supplied to the portion of the input terminal 30 of such a speaker, the signal current causes a current to flow through the voice coil 18 arranged in the air gap of the magnetic circuit. According to Fleming's left-hand rule, a force is applied in the axial direction, that is, in the vertical direction in FIG. Therefore, the diaphragm 20 connected to the voice coil 18 vibrates according to the signal current, and the sound is reproduced.

As shown in FIGS. 2 and 3, such a speaker is attached to the opening 37 formed in the side plates 36 of the speaker box 35 facing each other.
For example, the left channel speaker is attached to the left side plate 36, and the right channel speaker is attached from the opposite side to the right side plate 3.
You can attach it to 6. When the magnet 13 is not so large and the magnetic force is weak, the repulsive force between the magnetic circuits 11 is not large, so that there is no problem in mounting the speaker from the left and right, and the speaker can be easily attached.

As shown in FIG. 2, a reflector plate 38 is attached to the left and right side plates 36 at a predetermined angle with respect to these side plates 36, as shown in FIG. The reflector 38 is, for example, AB
It may be an S resin molded body or a wooden plate-like body, and is rotatably supported by the end portion of the side plate 36 via a hinge portion 39.

As described above, in the speaker device of the present embodiment, the speaker box 35 in which the magnetic circuit 11 of the speaker having the structure shown in FIG. 1 is back to back as shown in FIG.
It can be attached to. At this time, the bottom surfaces of the yokes 14 of the speakers of the magnetic circuit 11 may be in contact with each other, or may be mounted with a slight gap as shown in FIG. In the speaker device of FIGS. 2 and 3, the left speaker constitutes a left channel speaker and the right speaker constitutes a right channel speaker to constitute a stereo speaker system.

Here, the respective speakers are exactly the same as in FIG.
A speaker having a structure shown in is used. Therefore, since the polarities of the magnets 13 of the pair of speakers are the same,
As shown in FIG. 6, the pair of magnets 13 facing each other have their facing surfaces having the same pole. Therefore, the same effect as when the cancel magnet is attached can be obtained. That is, since the speaker shown in FIG. 1 is used as shown in FIG. 3, even if the speaker itself is not a magnetic shield speaker, it can be a magnetic shield speaker by bringing their magnetic circuits close to each other.

With this structure, the speaker box can be thinned by the thickness of two cancel magnets and the thickness of two shield covers, and a small speaker system can be provided. Figure 3 here
When the magnetic circuits having the above structure are used back-to-back with each other, it has been confirmed that the magnetic flux leakage is sufficiently measured to obtain a magnetically shielded speaker. The size of the magnet 13 at this time is a donut-shaped ferrite magnet having an outer diameter of 45 mm, an inner diameter of 22 mm and a thickness (dimension in the axial direction) of 4 mm, which is an outer magnet type speaker.

FIG. 4 shows a configuration of a 4-channel speaker system using two sets of the above speaker devices. That is, two speaker boxes 35 each having a speaker incorporated in the side plates facing each other are used. A reflector 38 is attached to each of both sides of the speaker box 35. The left speaker box 35 constitutes a left channel speaker, and the right speaker box 35 is a right channel speaker. Such a speaker device may be used as a speaker for a television receiver, for example.

5 and 6 show a second embodiment. This embodiment is applied to a speaker using a doughnut-shaped ferrite magnet having a diameter of 50 mm, an inner diameter of 22 mm and a thickness (dimension in the axial direction) of 6 mm. It is provided on the outer peripheral part of. The other structure is almost the same as the structure shown in FIG.

Such a speaker has a shield ring 4
The magnetic circuit 11 of the speaker is inserted into 3, and the outer peripheral side of the plate 12 is fixed to the inner peripheral portion of the shield ring 43 with an adhesive. The other manufacturing method is the same as that of the speaker shown in FIG.

As shown in FIG. 6, when the speakers having such a structure are contacted back to back in opposite directions, the tip ends of the shield rings 43 come into contact with each other, and the same magnetic shield effect as that of a shield cover of a general magnetic shield speaker is provided. Exert.
The tip surface of the shield ring 43 is preferably aligned with the bottom surface of the yoke 14 of the magnetic circuit 11, which facilitates manufacturing.

According to this structure, not only the magnet 13 of each speaker functions as a magnet for preventing the magnet 13 of the other speaker but also the leakage magnetic flux can be shielded by the shield ring 43. As a result, a speaker device having a higher magnetic shield effect can be obtained.

Next, modified examples of the above embodiment are shown in FIGS.
It will be explained by. This modified example, as shown in FIG.
A common shield ring 43 is used for the two loudspeakers, and a shield ring 43 having a length almost twice that of the shield ring 43 of the second embodiment is used.

As shown in FIG. 8, such a shield ring 43 is mounted so as to cover the magnetic circuits 11 of a pair of speakers arranged back to back from the outside. Therefore, with such a shield ring 43, the magnetic shields of the magnetic circuits 11 of the pair of speakers are positioned together with the pair of speakers arranged back to back in the circumferential direction.

When such a shield ring 43 is attached, the shield ring 43 is adhered and attached to the outer peripheral surface of the plate 12 of the magnetic circuit 11 of one speaker, and the shield ring 43 is adhered in this state. The speaker is attached to one side plate 36 of the speaker box 35 from the outside. And after this, the shield ring 43
Is assembled by mounting the speaker not attached to the speaker through the opening 37 of the opposite side plate 36, and inserting the magnetic circuit 11 of the speaker to be attached later into the shield ring 43 previously attached to the speaker on the opposite side.

Next, a third embodiment will be described with reference to FIG. In this embodiment, a cup-shaped shield cover 45 is attached to a pair of speakers. Here, each speaker is provided with a flat cup-shaped shield cover 45, and these shield covers 45 are attached in a state of being sandwiched between the frame 10 and the magnet 13. The shield cover 45 is made of iron and constitutes a part of the magnetic circuit.

When manufacturing such a speaker,
The plate 12 is adhered to the inside of the bottom of the frame 10.
The magnet 13 is adhered to the inside of the next shield cover 45. Then, an adhesive is applied to the upper surface of the yoke 14 to bond the magnet 13 and the yoke 14 together. At this time, the gap guide is inserted into the center pole 15 so that the outer circumference of the center pole 15 of the yoke 14 and the inner circumference of the plate 12 are concentric. Further, the shield cover 45 and the frame 10 are also bonded at the same time. After the adhesive is dried and fixed, the gap guide is removed.

Next, a voice coil spacer is inserted inside the voice coil 18 to position the voice coil 18. The voice coil spacer serves to center the outer circumference of the center pole 15 and the inner circumference of the voice coil 18 and to position the voice coil 18 at the same time.

Next, the outer peripheral side portion of the damper 23 is bonded to the plate 12 or the frame 10, and the inner peripheral side portion is bonded to the bobbin 19 around which the voice coil 18 is wound. Further, the edge portion of the diaphragm 20 made of cone paper is fixed to the outer peripheral side of the frame 10 by the fixing ring 21, and the inner peripheral side of the diaphragm 20 is wound with the voice coil 18.
It is adhered to the outer periphery of 9 and dried. Then, the tinsel wire 28 is soldered to the input terminal 30 on the terminal board 29, the voice coil spacer is removed, and the cap 22 is attached. After that, the magnet 13 is magnetized so as to have the polarity shown in the figure, whereby the speaker is completed.

Such a loudspeaker has a magnetic circuit 1
Fix so that 1 is close to each other. The magnets 13 of the first speaker and the second speaker function as canceling magnets, respectively, and the shield effect of the shield cover 45 results in a speaker device having better magnetic shielding performance. It should be noted that one such speaker does not become a magnetic shield speaker. Only when two speakers are installed as shown in FIG. 9, a magnetic shield type speaker is obtained. Moreover, since there is less leakage of magnetic flux when there is no gap between the tips of the shield covers 45 of the pair of speakers, a better magnetic shielding effect is exhibited.

Next, a fourth embodiment will be described with reference to FIG. In this embodiment, the plate 12 constituting the magnetic circuit is formed into a cup shape, and the function of the shield cover is generated at the outer peripheral side portion thereof. Therefore, the magnetic shield effect is further enhanced by such a plate 12.

The method of manufacturing this speaker may be exactly the same as that of the speaker shown in FIG. Both the first and second speakers do not become magnetically shielded speakers by themselves, but by combining the magnetic circuits 11 back to back as shown in FIG. 10, the magnets 13 of these speakers are mutually connected to the magnetic circuit of the other speaker. It works as a cancel magnet against. Moreover, the portion extended to the outer peripheral side of the plate 12 serves as a shield cover to further enhance the magnetic shielding effect. When the plates 12 of the pair of speakers are put together, a gap may be provided as shown in the figure, but the absence of the gap results in less leakage of magnetic flux, which makes the magnetic shield speaker even better.

Next, a fifth embodiment will be described with reference to FIG. In this embodiment, a large shield cover 45 is attached to the upper speaker, and the lower speaker has the same structure as the speaker shown in FIG. Therefore, the lower speaker may be manufactured similarly to the speaker of FIG. 1 above.

On the other hand, when assembling the upper speaker, the adhesive is applied to the inside of the bottom of the frame 12 to fix the plate 12. Next, an adhesive is applied to the bottom surface of the shield cover 45 to bond and fix the magnet 13.
At this time, it is necessary to align the magnet 13 and the center of the shield cover 45 by using a jig.

An adhesive is applied to the upper surface of the yoke 14, and at the same time, an adhesive is applied to the outer surface opposite to the bottom surface of the shield cover 45, and the frame 10 to which the plate 12 is attached is placed as shown in FIG. Insert the gap guide into the outer periphery of the center pole 15 before the adhesive hardens. The gap guide is for centering the outer peripheral portion of the center pole 15 and the inner peripheral portion of the plate 12.

Next, the voice coil 18 is inserted into the outer diameter portion of the voice coil spacer to position the voice coil 18, and the outer circumference of the center pole 15 and the inner circumference of the voice coil 18 are aligned. The outer periphery of the damper 23 is adhered to the plate 12 or the frame 10, and the inner peripheral portion is adhered to the outer periphery of the bobbin 19 around which the voice coil 18 is wound. In addition, the outer circumference of the diaphragm 20 is fixed to the fixed ring 2
Fixed to the outer peripheral side of the frame 10 by 1,
The inner peripheral portion is bonded to the outer periphery of the bobbin 19.

After the adhesive has dried, the lead wire of the voice coil 18 and the terminal on the terminal plate 29 on the outer peripheral surface of the frame 10 are soldered and connected by the tinsel wire 28. Then, the voice coil spacer is removed and the cap 22 is attached. Next, the speaker is completed by magnetizing the magnet 13 as shown in the figure. By combining such a speaker with the normal speaker shown in FIG. 1, the magnetic shield type speaker device shown in FIG. 11 is obtained.

As described above, in the speaker device of this embodiment, the shield cover 45 is attached to one of the pair of speakers, and the other speaker is an ordinary speaker. The magnetic shield speaker device is assembled so that the magnetic circuits of the first speaker and the second speaker face each other back to back.

At this time, the magnet of the second speaker is used as the cancel magnet of the first speaker,
The magnet 13 of the first speaker is used as the cancel magnet of the second speaker. In addition, the magnetic circuit 11
A shield cover 45 provided on one of the speakers is used to prevent the leakage magnetic flux in the vicinity of. In this case, the shield cover 45 functions so as to cover the magnetic circuits of the first speaker and the second speaker. Therefore, a speaker device having an excellent magnetic shield effect can be obtained.

[0051]

As described above, according to the present invention, a pair of speakers are arranged back to back so that the back sides of the respective magnetic circuits are in contact with or close to each other, and the magnets of the magnetic circuits of the respective speakers are arranged in the other side. The magnet of the magnetic circuit of the speaker is made to function as a magnetic shield magnet.

Therefore, by combining two non-magnetic shield type speakers, a magnetic shield type speaker device can be obtained, and since the cancel magnet is not used, the dimension in the axial direction can be reduced, and a thin speaker device can be obtained. Become.

According to the structure in which the shield rings are attached to the outer peripheral portions of the pair of speakers, and when the pair of speakers are arranged back to back, the tips of the shield rings come into contact with or come close to each other. Magnetic flux leakage is prevented by the outer shield ring.

According to the structure in which the single shield ring common to the pair of speakers is fitted to the outer peripheral portion of the magnetic circuit of the pair of speakers arranged back to back, the leakage magnetic flux is shielded by the shield ring. At the same time, the pair of speakers are positioned and coaxially arranged by this shield ring.

According to the structure in which the pair of loudspeakers respectively have cup-shaped shield covers, and the bottom plate portions of these shield covers are attached by being sandwiched between the magnet constituting the magnetic circuit and the frame. The shield effect is obtained by combining the cup-shaped shield covers.

When a pair of speakers each have a cup-shaped plate, and the cylindrical portions of these plates constitute a shield cover, the plate also serves as a shield cover, so that the leakage flux It is possible to simplify the structure for shielding the.

A pair of loudspeakers arranged back to back were mounted outward in openings on opposite side faces of the speaker box facing each other, and a reflector was provided obliquely to the pair of side plates. According to the configuration, it is possible to radiate sound from the magnetic shield type speaker including a pair of speakers arranged back to back in substantially the same direction.

If a pair of speakers arranged back to back in the speaker box constitute a left channel speaker and a right channel speaker, a stereo speaker system can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the structure of a speaker used in a speaker device.

FIG. 2 is a plan view of a speaker box having a pair of speakers attached thereto.

FIG. 3 is an enlarged cross-sectional view showing the internal structure of the speaker box.

FIG. 4 is a plan view showing an arrangement of speaker boxes according to a modified example.

FIG. 5 is a vertical cross-sectional view of a speaker used in the speaker device of the second embodiment.

FIG. 6 is a plan view of a speaker device in which the speakers are combined.

FIG. 7 is an external perspective view showing a shield ring of a modified example.

FIG. 8 is a plan view showing a speaker device using the same shield ring.

FIG. 9 is a vertical cross-sectional view showing a speaker device according to a third embodiment.

FIG. 10 is a vertical sectional view of a speaker device according to a fourth embodiment.

FIG. 11 is a vertical sectional view of a speaker device according to a fifth embodiment.

FIG. 12 is a vertical cross-sectional view showing the structure of a conventional magnetic shield speaker.

FIG. 13 is a vertical cross-sectional view showing the structure of another conventional magnetically shielded speaker.

[Explanation of symbols]

 10 frame 11 magnetic circuit 12 plate 13 magnet 14 yoke 15 center pole 18 voice coil 19 bobbin 20 diaphragm (cone paper) 21 fixing ring 22 cap 23 damper 28 tinsel wire 29 terminal plate 30 terminal 35 speaker box 36 side plate 37 opening 38 reflection Plate 39 Hinge part 43 Shield ring 45 Shield cover

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H04R 9/06 H04R 9/06 A

Claims (7)

[Claims] 1. A pair of loudspeakers, which are arranged back to back so that the back sides of the respective magnetic circuits are in contact with or close to each other, and the magnet of the magnetic circuit of each speaker is opposite to the magnet of the magnetic circuit of the other speaker. A speaker device that functions as a magnetic shield magnet. 2. A shield ring is attached to an outer peripheral portion of each of the pair of speakers, and when the pair of speakers are arranged back to back, the tip surfaces of the shield rings are in contact with or in close proximity to each other. 1. The speaker device according to 1. 3. A single shield ring common to a pair of loudspeakers is fitted to an outer peripheral portion of a magnetic circuit of the pair of loudspeakers arranged back to back.
The speaker device according to. 4. A pair of speakers each have a cup-shaped shield cover, and a bottom plate portion of the shield cover is sandwiched between a magnet forming a magnetic circuit and a frame and attached. The speaker device according to claim 1. 5. The speaker device according to claim 1, wherein each of the pair of speakers includes a plate having a cup shape, and a cylindrical portion of the plate constitutes a shield cover. 6. A pair of loudspeakers arranged back to back are mounted outward in openings of opposite side plates of the speaker box facing each other, and a reflector is obliquely attached to the pair of side plates. The speaker device according to claim 1, wherein the speaker device is provided. 7. The speaker device according to claim 6, wherein a pair of speakers arranged back to back in the speaker box constitute a left channel speaker and a right channel speaker.