JP3195520B2 - Repulsion magnetic circuit type speaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a repulsion magnetic circuit type loudspeaker, and more particularly to a repulsion magnetic circuit type loudspeaker capable of reducing the thickness of a magnetic circuit portion.

[0002]

2. Description of the Related Art FIGS. 9 and 10 show a conventional repulsion magnetic circuit type speaker in which two magnets 2, 3 are arranged so that the same poles are opposed to each other, and a magnetic material is provided between the two magnets 2, 3. The repulsion magnetic circuit 11 is configured by arranging the center plate 4, and the repulsion magnetic circuit type speaker 1 is configured by arranging the voice coil 5 in a repulsive magnetic field generated on the outer periphery of the center plate 4.

The magnets 2 and 3 and the center plate 4 are generally of a donut type, and are fixed by inserting a pole portion 12a of a holder 12 made of a non-magnetic material into a center hole thereof. Further, in order to increase the magnetic flux density of the repulsive magnetic field, an outer ring 13 made of a magnetic material may be disposed so as to face the center plate 4. In the figure, 5a is a bobbin of the voice coil 5, 14 is a frame, 15 is a diaphragm, 16 is a damper,
17 is a center cap, 18 is an edge.

[0004]

In the conventional repulsion magnetic circuit, the thickness and diameter of the magnet and the thickness of the center plate had to be increased in order to increase the repulsion magnetic flux. This results in a structure that contradicts the greatest advantage of the repulsion magnetic circuit type speaker, namely, the ability to make it thinner and lighter.

Further, as shown in FIG. 11, there is a problem that the magnetic flux 23 escapes in the inner circumferential direction of the center plate 4 and the magnetic flux cannot be used effectively.

An object of the present invention is to provide a repulsion magnetic circuit type speaker capable of increasing the magnetic flux density without increasing the size and weight of the magnetic circuit.

[0007]

According to the repulsion magnetic circuit type speaker of the present invention, two magnets are arranged so that the same poles are opposed to each other, and a center plate made of a magnetic material is arranged between the two magnets. In a repulsion magnetic circuit type speaker in which a voice coil is arranged in a repulsion magnetic field generated on the outer periphery of a plate, a magnet magnetized in a radial direction is incorporated in the center plate.

In this case, the radially magnetized magnet is inserted into the center plate, or the radially magnetized magnet is formed in a donut shape having the same thickness as the center plate, and is formed on the inner peripheral side of the center plate. Can be combined and arranged.

Further, in addition to the above configuration, a radially magnetized magnet ring may be arranged in the outer peripheral direction of the center plate, that is, instead of the outer ring in the conventional repulsion magnetic circuit.

In the above configuration, the magnet magnetized in the radial direction is incorporated in the center plate, but a magnetic gap is formed in the outer circumferential direction of the center plate between the center plate and the outer circumferential surface of the center plate. As described above, it is effective to arrange a magnet ring that is magnetized in the radial direction.

[0011]

The magnetic fluxes of the two magnets are pulled by the radially magnetized magnets incorporated in the center plate and concentrated on the center plate, thereby increasing the density of the repulsive magnetic flux generated on the outer peripheral side of the center plate. Further, the magnetic flux of the radially magnetized magnet incorporated in the center plate is also used as the effective magnetic flux. As a result, the magnetic flux crossing the voice coil becomes larger than before, and the efficiency can be improved.

Also, in the case where a radially magnetized magnet ring is arranged so that a magnetic gap is formed between the outer peripheral surface of the center plate and the outer peripheral surface of the center plate, the repulsive magnetic flux is reduced. The density of the magnetic flux crossing the voice coil by being pulled by the magnet ring is increased.

Further, in the case where a radially magnetized magnet is incorporated in the center plate and a radially magnetized magnet ring is also arranged on the outer periphery of the center plate, the repulsive magnetic flux can be more effectively used as a synergistic action. It is utilized and the magnetic flux density is further increased.

Accordingly, a predetermined magnetic flux can be obtained without increasing the thickness and diameter of the magnet and the center plate, so that the thickness and weight can be reduced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a repulsion magnetic circuit type loudspeaker according to the present invention will be described with reference to FIGS. 1 to 8, and the same components as those of the conventional one described with reference to FIGS. The description is omitted here.

1 to 3 show an embodiment of the first invention of the present invention. In the drawings, reference numeral 1 denotes a repulsion magnetic circuit type speaker, and two magnets 2 and 3 are arranged so that the same poles are opposed to each other. A center plate 4 made of a magnetic material is arranged between the two magnets 2 and 3, and a voice coil 5 is arranged in a repulsive magnetic field generated on the outer periphery of the center plate 4. Magnet magnetized in the direction (hereinafter "radial magnetized magnet")
6) is incorporated.

In the example of FIGS. 1 and 2, the radial magnetized magnet 6 is inserted into the center plate 4 so as to be located on the outer peripheral side, and the magnetizing direction is, as shown in FIG. When the magnets 2 and 3 have the N poles facing each other, the radial magnetized magnet 6 is magnetized so that the outside has the N pole. Further, the outer ring 13 as described in the conventional example is disposed.

In the example of FIG. 3A, the radial magnetized magnet 6 is inserted into the center plate 4 so as to be located on the outer peripheral side. In the example of FIG. 3B, the radial magnetized magnet 6 is inserted. Is formed in a donut shape with the same thickness as the center plate 4.
Are connected and arranged on the inner peripheral side. In FIG. 3B, when the upper and lower magnets 2 and 3 face the north poles in the direction of magnetization, the radial magnetized magnet 6 is mounted so that the north pole is on the outside. Magnetize.

FIGS. 4A and 4B show an embodiment of the second invention of the present invention.
That is, this is a configuration example in which the magnet ring 7 magnetized in the radial direction is arranged so that a magnetic gap is formed between the outer peripheral surface of the center plate 4 and the outer peripheral surface of the center plate 4. And in FIG. 4 (B),
As in the case of FIG.
Is formed in a donut shape with the same thickness as the center plate 4, and this is connected to the inner peripheral side of the center plate 4.

FIG. 5 to FIG. 7 are magnetic field analysis diagrams of the conventional repulsion magnetic circuit and the repulsion magnetic circuit used in the present invention, and are graphs comparing the results.
5A is a magnetic field analysis diagram and a graph of a conventional repulsion magnetic circuit in which the outer ring 13 is disposed, and FIG. 5B is a configuration shown in FIG. 3A which is an embodiment of the first invention of the present invention. FIG. 3 is a magnetic field analysis diagram and a graph of the repulsion magnetic circuit of FIG.

The horizontal axis of the graph indicates the distance in the Y-axis direction with the point A in the magnetic field analysis diagram taken as 0, and the magnetic force at each position on the vertical Y-axis is represented by Gauss. And the numerical value on the upper right is the energy product which is the area of the graph is Gausscm
It is displayed as.

FIG. 6A shows a magnetic field of the conventional repulsion magnetic circuit without the outer ring, and FIG. 6B shows a magnetic field of the repulsion magnetic circuit of FIG. 3A with the outer ring 13 removed. It is an analysis diagram and a graph.

FIG. 7A is a magnetic field analysis diagram and a graph of a conventional repulsion magnetic circuit in which the outer ring 13 is arranged.
FIG. 7 (B) 3 is an embodiment of a first invention of the present invention
3A and 3B are a magnetic field analysis diagram and a graph of the repulsion magnetic circuit having the configuration shown in FIG. Here, the numerical value (Gauss · cm) at the upper right of the graph is obtained by integrating the effective magnetic energy within a range of 6 mm from the center.

FIG. 8A is a magnetic field analysis diagram and a graph of the repulsion magnetic circuit of the configuration example of FIG. 4A according to the second invention of the present invention. Even if the magnet ring 7 magnetized in the radial direction is arranged so that a magnetic gap is formed between the magnetic ring 7 and the outer peripheral surface of the magnetic ring 4, the magnetic energy increases. FIG. 8B shows the configuration example of FIG. 4B, and the magnetic energy further increases.

As is apparent from the above comparison, the repulsion magnetic circuit used in the present invention has an increased magnetic energy as compared with the conventional repulsion magnetic circuit. For example, FIG.
Comparing FIG. 7A with FIG. 7B, the magnetic energy is increased by about 3.5% from 2512 Gauss to 2600 Gauss. Further, in the configuration example of FIG.
FIG. 4B shows an increase of about 8.6%.

[0026]

According to the repulsion magnetic circuit type loudspeaker of the present invention, the magnetic flux of the two magnets is pulled by the radial magnetized magnet incorporated in the center plate and concentrated on the center plate, and is generated on the outer peripheral side of the center plate. The repulsive magnetic flux density can be increased, and the magnetic flux of the radial magnetized magnet incorporated in the center plate can be used as the effective magnetic flux.

[0027] In the case where a radially magnetized magnet ring is arranged so that a magnetic gap is formed between the outer circumference of the center plate and the outer circumference of the center plate, the repulsive magnetic flux is reduced. The density of the magnetic flux that is pulled by the magnet ring and crosses the voice coil can be increased.

Therefore, a predetermined magnetic flux can be obtained without increasing the thickness and diameter of the magnet and the center plate, so that the repulsion magnetic circuit type speaker can be further reduced in thickness and weight.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a repulsion magnetic circuit type speaker according to the present invention.

FIG. 2 is an enlarged sectional view of a magnetic circuit unit.

3A and 3B are half-sectional enlarged cross-sectional views of a main part showing another configuration example of a magnetic circuit unit. FIG. 3A is a configuration example in which a radial magnetized magnet is inserted on the outer peripheral side of a center plate, and FIG.
Is a configuration example in which a magnetized magnet is coupled and arranged on the inner peripheral side of a center plate.

4A and 4B show a second embodiment of the repulsion magnetic circuit type speaker according to the present invention, in which FIG.
(B) is a half section enlarged sectional view of a main part showing another configuration example.

FIG. 5 is a graph showing a magnetic field analysis of a conventional repulsion magnetic circuit and a repulsion magnetic circuit used in the present invention and a graph comparing the results; FIG. 5 (A) is a conventional repulsion magnetic circuit in which an outer ring is arranged; Magnetic field analysis diagram and graph of (B)
3A is a magnetic field analysis diagram and a graph of a repulsion magnetic circuit having a configuration shown in FIG. 3A according to an embodiment of the present invention.

FIG. 6 is a graph showing a magnetic field analysis of a conventional repulsion magnetic circuit and a repulsion magnetic circuit used in the present invention and a graph comparing the results; FIG. 6 (A) is a conventional repulsion magnetic circuit without an outer ring; FIG. 6B is a magnetic field analysis diagram and a graph, respectively, of the repulsion magnetic circuit with the outer ring removed in the configuration of FIG. 3A.

FIG. 7 is a graph showing a magnetic field analysis of a conventional repulsion magnetic circuit and a repulsion magnetic circuit used in the present invention and a graph comparing the results; FIG. 7A is a conventional repulsion magnetic circuit in which an outer ring is arranged; Magnetic field analysis diagram and graph of (B)
FIG. 4 is a magnetic field analysis diagram and a graph of a repulsion magnetic circuit having a configuration shown in FIG. 3B according to an embodiment of the present invention.

8A and 8B are a magnetic field analysis diagram and a graph of the repulsion magnetic circuit of the configuration example in FIG. 4, wherein FIG. 8A is FIG.
The magnetic field analysis figure and graph in each magnetic circuit of (B).

FIG. 9 is a sectional view showing an example of a conventional repulsion magnetic circuit type speaker.

FIG. 10 is an enlarged sectional view of a main part showing a conventional repulsion magnetic circuit.

FIG. 11 is an enlarged half sectional view of a conventional repulsion magnetic circuit.

[Explanation of symbols]

 Reference Signs List 1 repulsion magnetic circuit type speaker 2 magnet 3 magnet 4 center plate 5 voice coil 6 radially magnetized magnet 7 radially magnetized magnet ring

──────────────────────────────────────────────────続 き Continued on the front page (56) References JP-A-6-233383 (JP, A) JP-A 2-13397 (JP, U) JP-A 58-152092 (JP, U) JP-A 52- 94834 (JP, U) Actually open 1953-19224 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04R 9/02 102 H04R 9/00

Claims (5)

(57) [Claims] 1. A magnet, wherein two magnets are arranged so that their poles face each other, a center plate made of a magnetic material is arranged between the two magnets, and a voice coil is arranged in a repulsive magnetic field generated on the outer periphery of the center plate. A repulsive magnetic circuit type speaker, wherein a magnet magnetized in a radial direction is incorporated in the center plate. 2. The repulsion magnetic circuit type speaker according to claim 1, wherein a radially magnetized magnet is inserted inside the center plate. 3. The repulsion according to claim 1, wherein the radially magnetized magnet is formed in a donut shape with the same thickness as the center plate, and is connected to the inner peripheral side of the center plate. Magnetic circuit type speaker. 4. A magnet ring, which is magnetized in a radial direction, is arranged in the outer peripheral direction of the center plate such that a magnetic gap is formed between the outer peripheral surface of the center plate and the outer peripheral surface of the center plate. , 2, 3 repulsion magnetic circuit type speaker. 5. Two magnets are arranged such that their poles face each other, a center plate made of a magnetic material is arranged between the two magnets, and a voice coil is arranged in a repulsive magnetic field generated on the outer periphery of the center plate. In the repulsion magnetic circuit type speaker, a radially magnetized magnet ring is arranged in the outer peripheral direction of the center plate so as to form a magnetic gap between the outer peripheral surface of the center plate. Repulsion magnetic circuit type speaker.