JPH0759195A - Speaker - Google Patents

Abstract

PURPOSE:To provide a speaker produced easily and inexpensively without the adoption of a special means by reducing the number of components possibly without use of a complicated component in a 2-way speaker using a repulsion magnetic circuit. CONSTITUTION:A plate P made of a magnetic material such as iron is inserted and held between two magnetic M1, M2 whose same pole is made opposite to each other and a voice coil 3 is arranged in a magnetic field by repulsion magnetism of both the magnets obtained at an outer circumference of the plate to drive a diaphragm 4 in this speaker. A 2nd voice coil 5 is arranged in a magnetic field produced around a face opposite to a face of the magnet M1 in contact with the plate P and a 2nd diaphragm 6 driven by the 2nd voice coil 5 is arranged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a repulsive magnetic circuit type speaker, and more particularly to a coaxial type speaker.

[0002]

2. Description of the Related Art Conventionally, there is a repulsive magnetic circuit type speaker that drives a diaphragm by arranging a voice coil in a magnetic field generated by repulsive magnetism of two magnets having the same pole side opposed to each other, and we also have a high efficiency. We also proposed this type of repulsive magnetic circuit type speaker for the purpose of thinness. In addition, JP-A-59
The speaker shown in FIG. 15 proposed in Japanese Patent Laid-Open No. 148500 is also an example thereof, and this speaker is configured as a coaxial type speaker, and a magnetic material is provided between two magnets M1 and M2 whose opposite poles face each other. A ring-shaped plate P made of is sandwiched, and a first voice coil 13 is arranged on the outer peripheral portion of the plate P so as to drive the first diaphragm 14 for low sound. The second voice coil 15 is also arranged in the peripheral portion to drive the diaphragm 16 for high sound. In the figure,
Reference numeral 11 is a frame, and 12 is a damper of the bass speaker unit.

On the other hand, as an example of a coaxial type loudspeaker which constitutes a high-pitched loudspeaker portion by utilizing the magnetic force of a magnetic-shielding magnet, there is the one shown in FIG. 16 which is proposed in Japanese Utility Model Laid-Open No. 64-11096. In the speaker shown in FIG. 16, the yoke 28 in the conventional magnetic circuit composed of the magnet M3, the yoke 28 and the top plate 29.
Of the magnet M4 is formed on the bottom side of the yoke, and the sub-yoke 27 is arranged on the bottom side of the magnet M4.
A sub magnetic gap is formed between a and the inner peripheral portion on the upper end portion side of the yoke 28, and the second voice coil 25 is disposed here to drive the high-frequency diaphragm 26. In addition,
In the figure, 21 is a frame, 22 is a damper for a low-pitched speaker portion, 23 is a voice coil, 24 is a low-pitched diaphragm, and 30 is a magnetic shield.

[0004]

In the coaxial type speaker using the conventionally proposed repulsive magnetic circuit shown in FIG. 15, in order to obtain good sound wave emission in the high frequency speaker section, the diaphragm 16 is the magnet M1. Of the first voice coil bobbin 13a for low-pitched sound, or a length longer than that of the first voice coil bobbin 13a for low-pitched sound. Will be required and the weight will increase. As a result, the high-frequency limit frequency is lowered and the bobbin portion is resonated, and the frequency characteristics are likely to be disturbed, which is an extremely inconvenient structure for a high-pitched speaker unit.

Further, if the inner diameter of the magnet is made small in order to give a sufficient magnetic flux density to the first voice coil 13 on the outer periphery of the magnets M1 and M2, a sufficient magnetic flux is given to the second voice coil 15 on the inner periphery. Since the density cannot be added, the efficiency of the high-pitched loudspeaker unit is extremely low, and the practicability becomes poor.

On the contrary, when the inner diameters of the magnets M1 and M2 are increased to increase the magnetic flux density inside the magnets and the efficiency of the high-frequency speaker section is increased, the outer diameters of the magnets are determined. There is a drawback that the total amount of magnets is reduced and, as a result, the magnetic flux densities of both are significantly reduced. Furthermore, since the outer peripheral portion of the edge 16a of the high-pitched diaphragm 16 is fixed in the middle of the low-pitched diaphragm 14, the vibration of the low-pitched diaphragm 14 is changed to the high-pitched diaphragm 1.
6 has a structure in which cross modulation easily occurs. Further, although the signal input wiring structure to the second voice coil 15 is not specified in the above-mentioned JP-A-59-148500, the assembly process is extremely difficult.

On the other hand, in the coaxial type speaker utilizing the magnetic force of the conventionally proposed magnetically shielded magnet shown in FIG. 16, the shape of the yoke 28 becomes complicated as shown in FIG. Since the dimensional accuracy is required, there is a drawback that the cost of the parts becomes high. Further, magnetic fluxes of both the magnet M3 and the magnetic-shielding magnet M4 flow in a portion of the yoke 28 in the vertical cross section shown in the figure, and magnetic saturation occurs, and
The magnetic flux density of the magnetic gap to be formed at the location tends to decrease. In order to avoid this, if the thickness of the vertical cross section is increased, it approaches the pole portion 27a of the sub-yoke 27, the leakage magnetic flux increases, and the magnetic flux density of the magnetic gap of the high frequency speaker portion further decreases. There is a drawback that ends up. Further, similar to the one disclosed in Japanese Patent Laid-Open No. 59-148500, the Japanese Utility Model Laid-Open No. 64-11096 does not specify the signal input wiring structure to the voice coil 25 of the high-pitched speaker section, but the assembly process is performed. Has a very difficult structure.

An object of the present invention is to effectively utilize the characteristics of the magnetic circuit in a two-way speaker using a repulsive magnetic circuit, use no complicated parts, and reduce the number of parts as much as possible. Another object of the present invention is to provide a speaker that can be easily and inexpensively produced without using any special means in the production process.

[0009]

In order to achieve the above-mentioned object, the speaker of the present invention has a plate made of a magnetic material such as iron sandwiched between two magnets whose opposite sides have the same polarity.
In a speaker that drives a diaphragm by arranging a voice coil in the magnetic field due to the repulsive magnetism of both magnets obtained on the outer periphery of the plate, at least one of the magnets is placed in the magnetic field generated near the surface opposite to the surface in contact with the plate of one of the magnets. Two voice coils are arranged and a second diaphragm driven by the second voice coil is provided. In this case, a pole piece made of a magnetic material may be provided on the surface opposite to the surface of at least one magnet in contact with the plate, and the second voice coil may be arranged on the outer peripheral portion of the pole piece. A flat diaphragm having a flat voice coil may be used as the second diaphragm, or a horn for the second diaphragm may be arranged.

[0010]

The basic structure of the repulsive magnetic circuit is, as shown in FIG. 1, a structure in which a plate P made of a magnetic material such as iron is sandwiched between two magnets M1 and M2 whose opposite poles face each other. As shown in FIG. 3, the magnetic fluxes generated from the poles of the two magnets on the side in contact with the plate P pass through the inside of the plate P while repelling each other, and are converged from the outer periphery of the plate P toward the outside. Is released. Therefore, by disposing the voice coil 3 in the vicinity of the plate P, the magnetic flux effectively acts on the voice coil and operates as a speaker. And the magnetic flux is the magnet M1,
The magnetic path is formed by returning to the pole of the surface of M2 opposite to the surface in contact with the plate P. In addition, as shown in FIG. 2, a repulsion magnetic circuit is also one in which an outer ring OL made of a magnetic material such as iron is arranged outside the voice coil 3. Note that FIG.
Also, in FIG. 2, AH is a holder made of a non-magnetic material such as aluminum.

The repulsive magnetic circuit does not form a closed circuit with a magnetic material like the magnetic circuit of a conventional speaker having a magnetic gap, but forms a magnetic path by the above magnetic flux distribution. As shown in FIG. 3, the magnetic flux is dispersed in the vicinity of this magnetic circuit, and the magnetic coil concentrates the magnetic flux for the voice coil 3 at a position other than the plate outer peripheral portion, for example, the surface opposite to the surface contacting the plate P of the magnet. Since the magnetic flux density is relatively high near the side surface as well, the second voice coil can be arranged in this magnetic field to drive the second diaphragm for high-pitched sound. Therefore, without increasing the cost,
A high-efficiency 2-way speaker can be configured and high frequency characteristics can be improved.

[0012]

FIG. 4 shows a first embodiment of the speaker according to the present invention, in which the repulsion magnetic circuit has the same structure as that shown in FIG. 1, and two magnets M1 having the same poles opposed to each other. M
A plate P made of a magnetic material such as iron is sandwiched between the two. In a speaker that drives the low-pitched diaphragm 4 by arranging the voice coil 3 in the magnetic field due to the repulsive magnetism of the two magnets obtained on the outer periphery of the plate P, at least one surface of the magnet M1 that is in contact with the plate P is opposite to the surface. The second voice coil 5 is arranged in the magnetic field generated near the side surface, and the second vibrating plate 6 for high sound driven by the second voice coil 5 is provided.

Specifically, a dome-shaped diaphragm 6 which is a diaphragm for high-pitched sound and a second voice coil 5 are integrally held by a base ring B made of synthetic resin, which is held by the magnet M1. It is attached to the top surface. FIG. 5 is an enlarged cross-sectional view of a main part, FIG. 6A is a perspective view showing an assembly example as seen from the bottom side, and FIG. 6B is a perspective view as seen from the top side. The base ring B has a "cross" shape on the inner circumference of the circular ring, and has a shape of a "circle-shaped ten". ,
A pair of conductors L for applying an input signal to the second voice coil 5 are arranged by means such as insert molding or fitting in a groove. In addition, a protrusion BT for fitting with the magnet M1 of the repulsion magnetic circuit is provided on the back surface of the frame of the ten-character shape.
4 are molded.

In the assembling method, the lead wire W is soldered to the conductor L in advance, the base ring B is fixed to the upper surface of the magnet M1 with an adhesive, and the integral dome diaphragm 6 is used.
Is adhesively fixed to the base ring B. The lead terminal VT (perforated) of the voice coil on the outermost periphery of the diaphragm is soldered to the pair of conductors L on the outer periphery of the base ring B. In FIG. 4, HT is a high-pitched sound terminal, and LT is a low-pitched sound terminal. As shown in FIG. 3, the magnet M1
Although not sufficient, the magnetic flux density sufficient to drive the voice coil is distributed on the upper surface of the dome diaphragm, and the dome diaphragm 6 can be driven by applying a signal current to the voice coil 5. The first voice coil 3 and the second voice coil 5 are, as shown in FIG.
It was connected by a crossover network in which one capacitor C was inserted on the high frequency side, and a high frequency characteristic was able to be improved by constructing a coaxial type two-way speaker using the diaphragm 4 for low sound and the diaphragm 6 for high sound. Note that the crossover network may have another circuit configuration. Further, as shown in FIG. 7B, it is also possible to adopt a so-called multi-amplifier system in which each voice coil is driven by a separate amplifier.

FIG. 8 shows a second embodiment,
FIG. 9 is a partial detailed view showing the improved efficiency of the speaker of the first embodiment. As shown in the partial assembly views of FIGS. 10A and 10B, the first embodiment is provided on the upper surface of the magnet M1.
The base ring B is arranged by the same method as described above, and the pole pieces 7 made of a magnetic material such as iron are adhesively fixed so as to be stacked on the base ring B. At this time, since the attraction force by the magnet M1 works, it is necessary to work using an assembly jig. A groove 7'for avoiding the frame B'of the base ring B is formed in the pole piece 7, and the back surface of the pole piece 7 is brought into close contact with the magnet M1. An integral dome diaphragm 6 is arranged so that the voice coil 5 is located on the outer peripheral portion of the upper portion of the pole piece 7.
As shown in FIG. 11, the effect of the pole piece 7 is such that the magnetic flux near the upper surface of the magnet M1 is converged and the magnetic flux density effective for driving the voice coil 5 is increased. Therefore, the sound pressure generated by the diaphragm 6 can be increased, and the efficiency of the speaker can be increased. The other configurations are the same as those in the first embodiment.

FIG. 12 is a partial detailed view of the vicinity of the high-frequency diaphragm of the speaker according to the third embodiment. In this embodiment, the film-like vibrating plate 6 of substantially the entire surface drive type is attached to a base ring B having a disk portion at the center, and the base ring is attached to the upper surface side of the magnet M1. FIG.
As shown in (A) and (B), a metal coil wound in a substantially spiral shape is arranged as a voice coil 5 on the surface of the film-shaped diaphragm 6. As an arrangement method, a metal foil (aluminum in this example) was attached to the film with an adhesive, and a predetermined voice coil was formed by an etching method. The vibrating plate 6 formed in this manner has its inner and outer peripheries fixed by the rings D2 and D1 that are electrodes and a frame. Other assembling methods are the same as those in the first embodiment. The voice coil 5 is parallel to the upper surface of the magnet M1, and in order to vibrate the diaphragm 6, the effective magnetic flux acting on the voice coil 5 utilizes a component parallel to the magnet M1. The magnetic distribution of the repulsive magnetic circuit is as shown in FIG.
Since the magnetic flux effective for the present embodiment is larger on the upper surface closer to the outer peripheral portion of No. 1, the diaphragm 6 has a ring shape along the outer peripheral portion of the magnet M1.

FIG. 14 is a partial detailed view of the vicinity of the high-frequency diaphragm of the speaker according to the fourth embodiment, in which a horn H is added to the speaker of the third embodiment to improve the efficiency of sound output. In this embodiment, an exponential horn having a phase plug h in the center is screwed and fixed to the disk part (phase plug) at the center of the base ring B by a screw N. It should be noted that the horn can be added in other embodiments.

[0018]

According to the speaker of the present invention, the coaxial 2-way speaker (coaxial speaker) can be constructed by effectively utilizing the characteristics of the repulsive magnetic circuit and additionally arranging the minimum necessary components. it can. In particular, by adding a second voice coil for treble and a diaphragm, and by constructing a two-way speaker with a crossover network, the high frequency band of the sound pressure frequency characteristic of the entire speaker is extended and the directional characteristic is wide. Become a thing,
It was possible to make a speaker with significantly improved performance. Of course, the outer ring made of a magnetic material may be arranged on the outer periphery of the plate to implement the invention.
The shape of the second diaphragm for high-pitched sound is not limited to that shown in the embodiment.

[Brief description of drawings]

FIG. 1 is a basic structural diagram of a repulsive magnetic circuit.

FIG. 2 is a basic structural diagram of a repulsive magnetic circuit in which an outer ring is arranged.

FIG. 3 is a half sectional view showing lines of magnetic force of a repulsive magnetic circuit.

FIG. 4 is a sectional view showing a first embodiment of the speaker according to the present invention.

FIG. 5 is an enlarged cross-sectional view of a main part.

FIG. 6 (A) is a perspective view showing an example of assembling a main part as seen from the bottom side.

FIG. 6 (B) is a perspective view showing an example of assembling the main part as seen from the upper surface side.

FIG. 7A is a network wiring diagram of the speaker according to the present invention.

FIG. 7B is a connection diagram of a speaker according to the present invention in a multi-amplifier system.

FIG. 8 is a sectional view showing a second embodiment.

FIG. 9 is a sectional view of an essential part of the second embodiment.

FIG. 10 (A) is a perspective view seen from the bottom surface side showing an example of assembling the main parts in the second embodiment.

FIG. 10 (B) is a perspective view seen from the upper surface side showing an example of assembling the main parts in the second embodiment.

FIG. 11 is a magnetic force line diagram of the repulsive magnetic circuit according to the second embodiment.

FIG. 12 is a cross-sectional view of a main part in the third embodiment.

FIG. 13 (A) is a perspective view seen from the bottom side showing an example of assembly of essential parts in the third embodiment.

FIG. 13B is a perspective view seen from the upper surface side showing an example of assembling the essential parts of the third embodiment.

FIG. 14 is a cross-sectional view of a main part showing a fourth embodiment.

FIG. 15 is a sectional view of a conventional two-way speaker using a repulsive magnetic circuit.

FIG. 16 is a cross-sectional view of a conventional two-way speaker that uses a magnetically shielded magnet.

[Explanation of symbols]

 1 frame 2 damper 3 first voice coil 4 first diaphragm 5 second voice coil 6 second diaphragm 7 pole piece B base ring B'base ring cross-shaped frame C capacitor D1 sticking frame / electrode ( Outer) D2 Attached frame and electrode (inner) H Horn h Face plug L Conductive part of base ring M1 Magnet M2 Magnet N Face plug thread P Plate VT Voice coil lead terminal (perforated) W Lead wire

Claims (4)

[Claims] 1. A magnetic field due to repulsive magnetism of both magnets obtained by sandwiching a plate (P) made of a magnetic material such as iron between two magnets (M1, M2) whose opposite sides are opposite to each other. In a speaker that drives a diaphragm (4) by arranging a voice coil (3) therein, at least one of the magnets (M1) has a first magnetic field in the vicinity of the surface opposite to the surface contacting the plate (P). Two voice coils (5) are arranged, and the second voice coil (5)
A speaker characterized by comprising a second diaphragm (6) driven by. 2. A pole piece (7) made of a magnetic material is provided on a surface of at least one magnet (M1) opposite to a surface in contact with the plate (P), and a second pole piece is provided on an outer peripheral portion of the pole piece. Speaker according to claim 1, characterized in that a voice coil (5) is arranged. 3. The speaker according to claim 1, wherein the second diaphragm (6) is a flat diaphragm having a flat voice coil. 4. The speaker according to claim 1, wherein a horn (H) for the second diaphragm is provided.