JP2000278792A - Speaker and speaker unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the efficiency of a magnetic circuit having low efficiency by forming a yoke and a frame surrounding the magnetic circuit into an integrated structure of a yoke to be utilized also as a frame. SOLUTION: A ring-like sub-plate 26 is formed so as to be continued to the upper end part of a sidewall yoke 31b. A second magnetic gap is formed between the inner diameter part of the sub-plate 26 and the outer peripheral face of the center pole 22a of the yoke 22 and the outer peripheral edge part of the sub-plate 26 is formed so as to be continued to the upper end part or sidewall part of the yoke 31b. In unifying the sub-plate 26 and the yoke 31b, the peripheral part of the ring-like disc of the sub-plate 26 is bent upward to form a cylindrical part, which is then engaged with the inner diameter of the yoke 31b and fixed so as to be united with the yoke 31b by spot welding or the like. Since the frame 5 and the sidewall yoke 31b surrounding a magnetic circuit are integrally constituted, a magnetism isolation effect can be obtained by a ring-like magnet 23 constituting a magnetic circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker and a speaker device suitable for being applied to a small speaker.

[0002]

2. Description of the Related Art Conventionally, as a small speaker 17, FIG.
The following has been proposed. This speaker is shown in FIG.
As shown in the figure, a ring-shaped magnet 1 having north and south poles magnetized in the vertical direction, a ring-shaped plate 2 mounted so as to sandwich the ring-shaped magnet 1, a center pole 3a and a flange 3b are integrated. A formed yoke 3 is provided, and a magnetic gap 4 is formed between the inner peripheral surface of the plate 2 and the outer peripheral surface of the center pole 3a of the yoke 3.

A frame 5 of a speaker is mounted on the plate 2, and an edge 7 is provided on an outer peripheral portion of the diaphragm 6. The outer peripheral portion of the cone-shaped diaphragm 6 is held by the frame 5 by the edge 7. ing. 8 is a gasket.

On the other hand, a voice coil bobbin 9 is attached to the inner peripheral portion of the diaphragm 6, and the voice coil bobbin 9
Is wound with a voice coil 10, and the voice coil 1
Numeral 0 is inserted into the magnetic gap 4 formed by the center pole 3a of the plate 2 and the yoke 3.

In FIG. 6, reference numeral 11 denotes a damper for holding the voice coil 10 in the magnetic gap 4. As the damper 11, for example, a corrugated damper obtained by impregnating a cloth with a synthetic resin is used.

Reference numeral 12 denotes an input terminal which supplies an audio signal from the input terminal 12 to the voice coil 10 through a tinsel wire 13. Reference numeral 14 denotes a cap for covering the upper surface of the voice coil bobbin 9 for preventing dust from entering.

As shown in FIG. 6, in the speaker 17, the ring-shaped magnet 1 → plate 2 → magnetic air gap 4
→ A center pole 3a of the yoke 3 → a flange 3b → a closed magnetic path through which a magnetic flux passes through a magnetic circuit of the ring-shaped magnet 1 is supplied, and an acoustic signal is supplied to the voice coil 10. Void 4
The voice coil 10 is driven inside, thereby driving the diaphragm 6, and radiating sound from the diaphragm 6.

The loudspeaker 17 forms the above-described magnetic circuit. However, since the polarity of the plate 2 and the flange 3b of the yoke 3 are different from each other, the leakage magnetic flux flows directly from the plate 2 to the flange 3b of the yoke 3. φ _L occurs, and there is a disadvantage that only about １ ／ of the magnetic force of the ring-shaped magnet 1 (hereinafter referred to as magnetomotive force) is used to drive the diaphragm 6.

A speaker 17a using a cancel magnet as shown in FIG. 7 has been proposed as a speaker which eliminates such a leakage magnetic flux. In describing FIG. 7, the same reference numerals are given to portions corresponding to FIG. 6, and detailed description thereof will be omitted.

In FIG. 7, a ring-shaped cancel magnet 15 magnetized in a direction opposite to the main drive ring-shaped magnet 1 is mounted near the outer periphery of the lower surface of the flange 3b of the yoke 3 in FIG. A cylindrical shield cover 16 with a bottom is attached so as to cover the outer periphery of the shield magnet 15 and the outer periphery of the cancel magnet 15.
6 to cancel the leakage magnetic flux. The rest is configured similarly to FIG.

[0011]

In the speaker 17 shown in FIG. 6, if the total magnetomotive force of the magnet is 1, the magnetomotive force generated in the magnetic gap 4 is about 1/3, and 2/3 is the leakage magnetic flux. Consumed. For example, the ring-shaped magnet has an outer diameter of 40φ, an inner diameter of 22φ, a thickness of 6 mm and a total magnetomotive force of 21,600 gauss, and the magnetomotive force generated in the magnetic gap 4 is about 7200 gauss.

The magnetic shield type speaker 17a shown in FIG.
In this case, the magnetomotive force in the magnetic gap 4 does not increase so much even though two magnets are used, and is limited to about 1.2 times that of FIG. 6 at 7200 × 1.2 = 8640 gauss. is there. Accordingly, of the two magnets 1 and 15, the cancel magnet 15 is slightly smaller, and the utilization rate of the total magnetomotive force of the two magnets is 1
/ 5, which means that the diaphragm 6 is not effectively used for driving.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a speaker and a speaker device which can increase the efficiency of an inefficient magnetic circuit and can obtain a magnetic-shielding effect with one magnet. Is what you do.

[0014]

The loudspeaker of the present invention is a loudspeaker comprising an outer-magnet type magnetic circuit formed by a center pole and a ring-shaped magnet, and a vibration system formed in a frame. It has a frame and yoke in which a yoke surrounding the circuit and a frame are integrally formed.

According to the present invention, since the frame and the side wall yoke 9 surrounding the magnetic circuit are integrally formed, the work of mounting the frame and the shield cover is not required and one magnetic circuit is formed. Thus, a magnetically shielded speaker and a speaker device can be obtained with the magnet.

Further, according to the present invention, by using one or two magnets and further providing a sub-plate on the first magnetic gap to be formed, the utilization rate of the total magnetomotive force of one or two magnets is improved. Thus, it is possible to obtain a speaker and a speaker device capable of effectively utilizing the total magnetomotive force and improving the sensitivity and the sound quality.

Further, according to the present invention, since a non-magnetic ring-shaped airtight member is interposed between the sub-plates forming the first magnetic gap and the second magnetic gap, the thin air resistance due to the inner and outer diameters of the voice coil is reduced. And the resonance sharpness Q at the lowest resonance frequency of the loudspeaker is reduced, so that the low-frequency range can be easily expanded with a small loudspeaker.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a speaker according to the present invention will be described below with reference to FIGS. FIG. 1 is a side sectional view of a speaker of the present example, FIG. 2 is a side sectional view of another speaker of the present example, FIG. 3 is a side sectional view of still another speaker of the present example,
FIG. 4 is an explanatory diagram of a method of mounting a sub-plate of a speaker and a magnetic circuit according to the present invention. Hereinafter, portions corresponding to FIG. 6 in the drawings are denoted by the same reference numerals.

The speaker 17b shown in FIG. 1 has a bottom yoke 31 forming a funnel-shaped frame 5 and a bottomed cylindrical shield.
a and the side wall yoke 31b are integrally formed of a metal member, and a through hole 31c is formed at a central position of the bottom yoke 31a. A magnet guide 31d is formed in a step shape concentrically with the through hole 31c formed in the bottom yoke 31a.

A through hole 31 formed in the bottom yoke 31a
The center pole 22a and the flange 22b are substantially inverted T
The upper surface of the flange 22b is adhesively fixed to the bottom yoke 31a by inserting the center pole 22a until the flange 22b of the yoke 22 integrally formed in a letter shape contacts the back surface of the bottom yoke 31a.

The inner diameter of the ring-shaped magnet 23 is fitted to the step of the magnet guide 31d of the bottomed cylindrical bottom yoke 31a forming the shield part.
a is bonded via an adhesive or the like.

The ring-shaped magnet 23 is magnetized with an N pole and an S pole in the vertical thickness direction, and has a cylindrical side wall yoke 31b.
Has an outer diameter smaller than the inner diameter.

A ring-shaped plate 24 is bonded and fixed on the N pole of the ring-shaped magnet 23, and a first magnetic gap 25 is formed between the inner peripheral surface of the plate 24 and the outer peripheral surface of the center pole 22 a of the yoke 22. Form.

In this embodiment, the side wall yoke 31b
A ring-shaped sub-plate 26 is provided continuously at the upper end of the. In this case, the inner diameter of the plate 26 and the yoke 2
The second magnetic gap 27 is formed between the outer peripheral surface of the center pole 22a and the outer peripheral edge of the plate 26 so as to be continuous with the upper end or the side wall of the side wall yoke 31b. In this example, when this sub-plate is integrated with the side wall yoke 31b, as shown in FIG. 1 or FIG. 4 (B), the sub-plate 26 is formed by bending the periphery of the ring-shaped disk upward to form a cylindrical portion 26a. Then, the cylindrical portion 26a is fitted inside the inner diameter of the side wall yoke 31b, and fixed so as to be integrated with the side wall yoke 31b by spot welding or the like. As described above, when the sub-plate 26 is configured, the first ring-shaped magnet 23 and a second ring-shaped magnet 30 described later are formed.
(See FIG. 3).

In the case of FIG. 4A, when the frame 5 and the bottomed cylindrical side wall yoke 31b and the bottom yoke 31a are integrally formed, a step 35 is formed between the funnel-shaped frame 5 and the side wall yoke 31b. And the ring-shaped step 3
This is a case where a ring-shaped sub-plate 26 is placed and fixed on spot 5 by spot welding or the like.

The sub-plate 26 is formed between the inner diameter of the center hole of the plate 24 and the outer diameter of the center pole 22a through a second magnetic gap 27 formed between the inner diameter of the center hole of the sub-plate 26 and the outer diameter of the center pole 22a. First magnetic gap 25
The voice coil bobbin 9 is inserted through the inside. At the position corresponding to the first magnetic gap 25 at the tip of the voice coil bobbin 9, the damper 1 is wound so that the voice coil 10 is wound.
1, the voice coil bobbin 9 is held by swingably fixing the outer diameter of the damper 11 on the frame 5 or the sub plate 26. As the damper 11, a concentric corrugated damper in which a cloth is impregnated with a synthetic resin is used.

The upper part of the voice coil bobbin 9 is joined to the inner diameter of the cone-shaped diaphragm 6, and the outer diameter of the diaphragm 6 is joined to the maximum diameter opening of the frame 6 via the edge 7 via the gasket 8. Then, a dome-shaped dust-preventing cap 14 is provided above the voice coil bobbin 9. An audio signal is supplied to the voice coil 10 from an input terminal 12 provided at a predetermined position of the plate 5 via a tinsel wire 13.

According to the magnetic circuit of the loudspeaker 17b having the above-described configuration, the magnetic flux emitted from the N pole of the ring magnet 23 is a ring-shaped plate 24 joined to the upper side of the N pole.
Magnetic gap 25 → the magnetic path φ ₁ reaching the south pole of the ring-shaped magnet 23 and entering the flange 22b with the center pole 22a of the yoke 22 facing downward, and the ring-shaped magnet 2
The magnetic flux emitted from the N pole of No. 3 enters the side wall yoke 31b from the sub-plate 26 via the plate 24 → the first magnetic gap 25 → the center pole 22a of the yoke 22 upward through the second magnetic gap 27, Bottom yoke 31 of yoke 22
a, the magnetic path φ reaching the S pole of the link-shaped magnet 23
₂ occurs.

In this case, in the first magnetic gap 25, φ ₁
It can be understood that since the magnetic fluxes of the magnetic path of + φ ₂ are added to each other, the magnetomotive force in the first magnetic gap increases as compared with FIGS. 6 and 7.

Now, the magnetomotive force of the ring magnet 23 is 2
Since the magnetic resistances R ₁ and R ₂ in the magnetic gaps 25 and 27 are equal because the magnetic fluxes pass through the first and second magnetic gaps 25 and 27, the first magnetic gap 25 is repeated once in the magnetic path of φ _1. Assuming that the magnetomotive force is 1, since the magnetic flux passes through the first and second magnetic air gaps 25 and 27 twice in the magnetic path of φ ₂ , the magnetomotive force is 0.1.
It becomes 5. In this case, the magnetic path φ passing through the first magnetic gap 25
_Since the magnetic fluxes of ₁ and φ ₂ are in the same direction, the magnetomotive force is 1.5
May be considered.

The actual measurement results are shown below. Now, the size of the ring-shaped magnet 23 is set to an outer diameter of 40 mm × an inner diameter of 22 mm.
φmm × thickness 6 mm, thickness of sub-plate 26 is 0.6 mm, thickness of plate 24 is 2.0 mm, outer diameter of center pole portion is 15.9 mm, distance between upper surface of plate 24 and lower surface of sub-plate 26 The magnetomotive force at the magnetic gap 4 in FIG. 6 when the distance was 5.5 mm was 7200 gauss, and the magnetomotive force at the first magnetic gap 25 shown in FIG. 1 of the present invention was 12800 gauss.

This is because the magnetic resistance (or permeability μ) of the first and second magnetic air gaps 25 and 27 is not considered to be equal and R
Assuming that ₁ = 0.3R, the magnetomotive force in the first magnetic gap 25 is approximately 12800/7200 = 1.78 倍 1.8 times.

Assuming that only one third of the total magnetomotive force is used in the ring-shaped magnet 1 as in the prior art,
The magnetomotive force when using two magnets is improved to 1.8 / 3 times.

Further, in the speaker 17b having the configuration shown in FIG. 1, since the polarity between the plate 24 and the sub-plate 26 is reversed,
It is necessary to keep a certain distance. In the present invention, the plate 24
The distance between the upper surface of the sub-brake and the lower surface of 26 is 5.5m
m, but the magnetomotive force of the first magnetic gap 25 was 9800 gauss when this distance was 4 mm, so this distance was sufficient within 4 mm to 5.5 mm, and 5.5 mm or less.
It is not necessary to be more than mm apart.

As described above, according to the loudspeaker 17b having the structure shown in FIG. 1, the magnetomotive force in the first magnetic gap 25 can be increased to about 1.8 / 3 times, so that the sensitivity is improved by about 5 dB. Not only is it possible, but the leakage magnetic flux φ _L passes through the side wall yoke 31b and the bottom yoke 31a, so that a magnetic shield type speaker can be formed with only one ring-shaped magnet 23.

FIG. 2 shows a speaker 17c according to another embodiment of the present invention.

The speaker 17c in FIG. 2 is the speaker 1 in FIG.
An airtight member 32 made of a non-magnetic member is joined between the plate 24 and the sub-plate 26 of FIG. This hermetic member 32 has exactly the same structure as that of FIG. 1 except that a synthetic resin member is formed in a ring shape and joined between the upper surface of the plate 24 and the lower surface of the sub-plate 26 with an adhesive or the like.
The same reference numerals are given and duplicate description is omitted.

In the configuration shown in FIG. 2, the diaphragm 6 is the voice coil 1
The resistance of the air flow (air flow) 33 passing between the outer diameter of the center pole 22a and the inner diameter of the voice coil bobbin 9 and between the outer diameter of the voice coil bobbin and the inner diameter of the airtight member 32 when driven by zero is increased. The resonance sharpness Q at the lowest resonance frequency of the speaker 17c is reduced so that even a small speaker 17c can easily expand the low frequency range.

In the case of FIG. 3, the plate 24 and the sub-plate 26 are replaced with the airtight member 32 made of a non-magnetic material of FIG.
The second ring magnetized in the opposite direction to the first ring-shaped magnet 23
2 except that the ring-shaped magnet 30 is disposed, the same reference numerals are given to portions corresponding to FIG.

The magnetic path shown in FIG. 3 will be described with reference to an enlarged view showing the magnetic circuit shown in FIG.

N above the first ring-shaped magnet 23
The N-pole side of the second ring-shaped magnet 30 faces the plate 24 joined on the pole, and is joined on the plate 24. Therefore, the joining surface of the second ring-shaped magnet 30 that contacts the sub-plate 26 is an S pole.

In the magnetic circuit having this configuration, the magnetic paths φ ₁ and φ ₂ described with reference to FIG. 1 are generated from the first ring-shaped magnet 23.

Further, the N of the second ring-shaped magnet 30
The magnetic flux coming out of the pole is the plate 24 → the first magnetic gap 25 →
The center pole 22a faces upward → the second magnetic gap 27 →
Subplate 26 → S of second ring-shaped magnet 30
Closed magnetic path φ ₃ passing through pole and second ring-shaped magnet 30
N pole → plate 24 → first magnetic gap 25 → facing down center pole 22a → flange 22b of yoke 22 →
Bottom yoke 31a → side wall yoke 31b → sub plate 2
6 → A closed magnetic path φ ₄ reaching the south pole of the second ring-shaped magnet 30 is formed.

In the case of FIGS. 4A and 4B, the magnetic flux passing through the closed magnetic path φ ₁ + φ ₂ + φ ₃ + φ ₄ is the first magnetic gap 2
Φ ₃ + φ ₂ is 2 because they pass through 5 so that they are added to each other.
0.5 + 0.5 = to pass through two magnetic gaps 25 and 27
1 and φ ₁ + φ ₄ pass through only one magnetic gap 25, so that 1 + 1 = 2, φ ₁ + φ ₂ + φ ₃ + φ ₄ = 3, and the actual value of the magnetomotive force in the first magnetic gap 25 is 2370.
Since it becomes 0 gauss and reaches about 3.3 times, the utilization rate of the magnet can be increased to about 3.3 / 6.

When such a strong magnetomotive force is used, the sound pressure of the speaker 17d can be increased by about 10 dB.

FIG. 5 shows an example of a speaker device in which the speaker of FIG. 3 is mounted on a small speaker box 50. 5. Referring to FIG. 5, in FIG. 5, reference numeral 50 denotes a small speaker box, which faces a speaker sound emission hole 51a formed in a baffle plate 51 provided on the front surface of the speaker box 50, as shown in FIG. The speaker is fixed as shown in the figure. Also, an acoustic signal from an input terminal 52 provided at a predetermined position outside the speaker box 50 is supplied to the input terminal 12 of the speaker via a connection line 53, and the acoustic signal from the input terminal 12 is supplied to a tinsel wire 13. Through the voice coil 10.

The speaker sound output hole 5 of the baffle plate 51
A duct 54 having an opening 54a on the same surface as 1a is provided,
The phase of the sound emitted from the back of the diaphragm 6 of the speaker is inverted and radiated from the duct 54 to the outside of the speaker box 50 so as to widen the bass range of the sound emitted from the front of the diaphragm 6. This example of FIG. 5 constitutes a phase inversion type speaker device.

In the loudspeaker device according to the present embodiment, since the magnetic force for driving the diaphragm 6 of the loudspeaker is large as described above, the sensitivity and sound quality of the loudspeaker device are improved, and the resonance sharpness of the loudspeaker at the lowest resonance frequency is obtained. It is possible to obtain a speaker device in which Q can be reduced and a reproduction range of low sound when the small speaker box 50 is used can be expanded.

Further, the loudspeaker shown in FIGS. 1 and 2 may be mounted on a small loudspeaker box 50 as in the example shown in FIG. 5 to obtain a loudspeaker device. In this case, it can be easily understood that the same operation and effect as in the example of FIG. 5 can be obtained.

It is to be noted that the present invention is not limited to the above-described example, but may take various other configurations without departing from the gist of the present invention.

[0051]

According to the loudspeaker and the loudspeaker device of the present invention, the sub-plate is formed by integrally forming the bottomed cylindrical side wall yoke and bottom yoke formed so as to surround the magnetic circuit with the frame. A magnetically shielded speaker can be obtained at low cost by using a single magnet, and the magnetomotive force (magnetic force) in the magnetic gap of the magnetic circuit is increased by about 1.8 times compared to the conventional one, and the sound pressure of the speaker is increased by about 5 dB. Can be done.

By arranging two ring-shaped magnets in opposite polarities and providing a sub-plate, the magnetomotive force in the magnetic gap is about 3.3 times stronger than in the past, and the sound pressure of the speaker is about 10 dB. Can be raised.

Further, by providing an air-tight member made of a non-magnetic member between one ring-shaped magnet and a sub-plate constituting a magnetic circuit, the air resistance flowing into the inner and outer diameters of the voice coil is increased, so that the speaker at the lowest resonance frequency of the speaker can be obtained. Q
And a speaker and a speaker device that can easily expand the low frequency range of the speaker can be obtained.

[Brief description of the drawings]

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

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

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

FIG. 4 is a diagram illustrating a method of mounting a sub-plate of a speaker and a magnetic circuit according to the present invention.

FIG. 5 is a sectional view showing an example of the speaker device of the present invention.

FIG. 6 is a sectional view showing an example of a conventional speaker.

FIG. 7 is a cross-sectional view showing an example of another conventional speaker.

[Explanation of symbols]

5 ‥‥ frame, 6 ‥‥ diaphragm, 10 ‥‥ voice coil, 22 ‥‥ yoke, 22a ‥‥ center pole, 22
b ‥‥ flange, 24 ‥‥ plate, 25, 27 ‥‥ first and second magnetic gap, 26 ‥‥ sub-plate, 23,
30 {first and second ring-shaped magnets, 31a}
{Bottom yoke, 31b} Side wall yoke

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takayuki Mizuuchi 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Ikuo Shinohara 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo No. Sony Corporation F term (reference) 5D012 BB01 BB03 BB04 BB09 BD00 CA09 5D017 AD12

Claims (5)

[Claims] 1. A speaker comprising an external magnetic type magnetic circuit formed by a center pole and a ring-shaped magnet, and a vibration system formed in a frame, wherein a yoke surrounding the magnetic circuit and the frame are provided. A speaker having a frame and yoke integrally formed with the speaker. 2. A second magnetic gap is formed by providing a sub-plate between the center pole and the frame and yoke above the center pole and a first magnetic gap formed by the magnetic circuit. The speaker according to claim 1, wherein the speaker is formed. 3. A ring-shaped magnet, which is magnetized with a polarity opposite to that of the ring-shaped magnet in a thickness direction, is disposed between the plate forming the first magnetic gap and the sub-plate. The speaker according to claim 1 or 2. 4. An airtight member made of a ring-shaped non-magnetic member is provided between the plate forming the first magnetic gap and the sub-plate. The described speaker. 5. A speaker device having a speaker attached to a baffle plate on a front surface of a speaker box, wherein the speaker is the speaker according to claim 1, 2, 3, or 4.