JP3161679B2 - 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 speaker in which a diaphragm, a coil and a magnetic circuit are housed in a frame, and more particularly to a lightweight speaker in which the frame is formed of a synthetic resin.

[0002]

2. Description of the Related Art A conventional loudspeaker includes a frame made of an iron-based metal, in which a cone-shaped diaphragm, a coil for applying vibration to the diaphragm, and a magnetic circuit for applying a magnetic field to the coil are housed. General. The magnetic circuit has a yoke of a magnetic material called a pole piece and a magnet. The magnet is made of a rare earth material, and the yoke is made of a magnetic material having high magnetic permeability such as soft iron or ferrite.

[0003] The above-mentioned conventional loudspeaker has a very large overall weight, and in particular, the proportion of the increase in weight of the iron-based metal frame is increasing. Even if the speaker used for the home acoustic device is heavy to some extent, there is no problem because the speaker is often always fixed and used. However, since a vehicle-mounted speaker is always subjected to vehicle body vibration, if the weight is large, the speaker itself is likely to be loosened or fatigued due to vibration of the speaker itself. Further, since the in-vehicle speaker is mounted in a narrow place, the mounting and replacement work becomes difficult with a heavy speaker. Particularly, if the weight of the speaker installed in the door of the automobile is large, the weight of the door increases, which is not preferable.

Further, when a frame made of an iron-based metal is used, the magnetic field to be applied to the coil from the magnetic circuit is disturbed by the influence of the frame, and further, eddy current loss and hysteresis loss occur in the frame. However, the performance of the speaker itself may be deteriorated.

[0005]

Therefore, if the frame of the speaker is formed of a synthetic resin material such as ABS,
It becomes lightweight and becomes the best thing as an in-vehicle speaker,
Also, by using a synthetic resin that is a non-magnetic material,
Disturbance of the magnetic field of the magnetic circuit, eddy current loss and hysteresis loss do not occur.

However, when the entire frame is formed only of synthetic resin, the frame has poor heat dissipation,
Joule heat generated from the voice coil cannot be sufficiently radiated to the outside of the speaker, and heat is accumulated around the voice coil, which may cause disconnection of the coil.

Further, since the magnetic circuit is constituted by a magnet and a yoke made of metal, the members constituting the magnetic circuit are heavy. When this heavy member is supported by a resin frame, the supporting strength is reduced. Furthermore, when the members constituting the magnetic circuit are fixed to the frame with an adhesive, the adhesive strength of the adhesive tends to decrease due to the aforementioned Joule heat. In order to cope with this decrease in the adhesive strength, it is conceivable to fix members constituting the magnetic circuit to the frame with screws. However, the resin frame is inferior in durability against the tightening force of the screw, and may be damaged from the screw tightened portion.

The present invention has been made to solve the above-mentioned conventional problems. The frame is made of a synthetic resin material to reduce the weight, and furthermore, the heat dissipation from the coil is improved so that the problem due to heat does not occur. It is intended to provide a speaker.

Another object of the present invention is to provide a speaker in which the frame is formed of a synthetic resin to reduce the weight, and that the members constituting the magnetic circuit can be supported with sufficient strength.

[0010]

According to the present invention, there is provided a loudspeaker in which a diaphragm, a coil for applying vibration to the diaphragm, and a magnetic circuit for applying a magnetic field to the coil are provided in a frame. Formed of resin material,
A radiator plate made of a non-magnetic metal material is attached to the inner surface of the base of the frame, and members constituting a magnetic circuit are attached to the radiator plate.

Further, it is preferable that a hole communicating with each other is formed in the heat radiating plate and the frame, and the space inside and outside the frame is connected through the hole.

Further, it is possible to provide a mounting member which presses down a member constituting the magnetic circuit from the diaphragm side, and the mounting member is fixed to the heat sink by screws.

[0013]

According to the present invention, the frame is formed of a synthetic resin material such as ABS. More preferably, the magnet constituting the magnetic circuit is a bond magnet (plastic magnet), the yoke is formed of soft ferrite or the like, and the members constituting the magnetic circuit are made as light as possible to reduce the weight of the entire speaker. . This lightweight speaker is particularly suitable for use in a vehicle and is lightweight so that mounting work and the like are easy. Also, there is no eddy current loss or hysteresis loss as in the case of using an iron-based metal frame.

A heat radiating plate made of a non-magnetic material is attached to the inner surface of the base of the frame. By using a heat-dissipating plate made of a non-magnetic material, a magnetic circuit such as a conventional iron-based frame is not adversely affected. This radiator plate is formed of aluminum or aluminum alloy, brass, zinc alloy, copper, copper alloy, or the like. In consideration of heat dissipation, copper or a copper alloy or an aluminum alloy is suitable, but aluminum or an aluminum alloy is most suitable in terms of workability. The radiator plate is preferably drawn, and members such as a magnet and a yoke constituting a magnetic circuit are positioned and installed on the stepped portion in the drawn radiator plate.

By providing a heat radiating plate made of a non-magnetic material,
The Joule heat of the coil is easily conducted to the outside through the heat radiating plate, so that the temperature around the coil can be prevented from rising. Further, by forming holes communicating with each other in the heat radiating plate and the frame, and connecting the inside and the outside of the frame with the holes, heat in the frame can easily escape to the outside from the holes. That is, the air in the frame moves in and out of the holes due to the vibration of the diaphragm, and the ventilation in the frame is performed, so that the heating around the coil is prevented. In order to prevent dust and dirt from entering the magnetic circuit, the holes formed in the heat sink are preferably arranged with small holes, and more preferably, around the magnetic circuit in the frame. The space communicates with the outside only through the small holes. As a result, heat dissipation can be ensured, and the function of preventing dust from entering from the outside can be sufficiently exhibited.

When the members such as magnets and yokes constituting the magnetic circuit are supported by the heat radiating plate, the support of the yokes and magnets is better than that in which the members of the magnetic circuit are supported only by the synthetic resin frame. Strength increases. Further, by providing a mounting member for holding the members constituting the magnetic circuit, and fixing the mounting member and the heat sink with screws, the magnetic circuit can be firmly fixed and the frame is not damaged by the tightening force of the screws. .

[0017]

Embodiments of the present invention will be described below. FIG. 1 is a cross-sectional view showing a dynamic speaker used as an on-vehicle or the like as one embodiment of the present invention, and FIG. 2 shows a heat sink attached to the speaker.
Is a plan view, and (B) is a sectional view. In the loudspeaker shown in FIG. 1, the frame 11 is injection-molded with a synthetic resin material such as ABS. The frame 11 has a conical shape, and a hole 11a is formed in a side surface on the upper side in the figure. Further, reinforcing ribs 11b and 11c are provided integrally on the outer periphery of the frame 11. The bottom (base) of the frame 11
Has a cylindrical hole 11d, and a ventilation hole 11e is formed in the middle horizontal portion. This ventilation hole 11e
The holes are round holes or oval holes, and are arranged at a predetermined pitch in the circumferential direction.

A heat radiating plate 12 is mounted on the inner surface of the bottom of the frame 11. The radiator plate 12 is formed by drawing from an aluminum or aluminum alloy plate. As shown in FIGS. 2A and 2B, the heat sink 12 has a ring-shaped magnetic circuit storage space B formed therein, in which a step 12a is formed on the inner peripheral side and a step 12a is formed on the outer peripheral side. 12b is formed. Further, a bobbin moving space D described later is formed at the bottom of the heat sink 12. At the center of the heat sink 12, a mounting hole 12c is formed. The illustrated upper portion of the heat sink is a flange portion 12d, and a ventilation hole 12e is formed in the flange portion 12d.
This ventilation hole 12e is a small hole having a very small diameter, and is shown in FIG.
As shown in FIG.

As shown in FIG. 1, the heat radiating plate 12 is tightly fixed to the inner surface of the bottom of the frame 11. The bottom of the heat sink 12 is exposed to the outside at a large area at the cylindrical hole 11d at the base of the frame 11. The heat sink 12 is inserted into a molding die when the frame 11 is injection-molded, and the heat sink 12 and the frame 11 are integrally formed. Alternatively, after the frame 11 is formed, the heat radiating plate 12 is fitted to the bottom of the frame 11,
It may be fixed by an adhesive or the like. FIG.
As shown in the figure, the ventilation holes 12e of the heat radiating plate 12 communicate with the ventilation holes 11e formed at a constant pitch in the horizontal portion of the frame 11, and the frame 11 around the magnetic circuit A
The inner space E and the outer space are defined by the ventilation holes 12e and 11e.
And are connected through.

In the frame 11, there is provided a cone-shaped diaphragm 13 made of paper or the like. The diaphragm 13 is configured such that the edge of the conical bottom portion 13a is
4 is connected to the opening edge 11 f of the frame 11. The deformed portion 14 has a cross section curved in a semicircular shape. The dome portion 15 is connected to the inside of the conical head 13 b of the diaphragm 13, and the damper 16 is connected to the outside. The damper 16 is formed of a paper material, a resin material, or the like, and has a concentric waveform and is freely deformable. The damper 16 connects the conical head 13b of the diaphragm 13 to the inner surface of the frame 11, and the damper 16 and the deformed portion 14
Are supported so as to be able to vibrate. Conical head 1 of diaphragm 13
A cylindrical bobbin 17 is connected to 3b, and coils (voice coils) C1 and C2 are provided on the outer periphery of the bobbin 17.

In the internal space of the frame 11, a dome portion 15 is provided inside the conical head 13b of the diaphragm 13 and a damper 16 is provided between the outside and the inner surface of the frame 11. I have. Therefore, damper 1
The space E below the space 6 and the space F above the damper 16 are isolated without communicating with each other. Further, a space E between the lower portion of the damper 16 and the frame 11 is provided.
Is also isolated from the space G inside the bobbin 17. The space E has a ventilation hole 12 e formed of a plurality of small holes formed in the heat sink 12 and a ventilation hole 11 e of the frame 11.
Only communicates with the outside air. Since the space E is connected through a plurality of small holes, ventilation of the space E is possible. However, dust and dirt can be prevented from entering the space E from the outside, and dust and the like adhere to the magnetic circuit A. It is difficult to do.

That is, the invention in this embodiment includes a damper 16 connecting the diaphragm 13 and the frame 11,
Bobbin 17 having coils C1 and C2 and frame 11
Is communicated with the outside air only through the ventilation holes 12e of the heat sink 12 and the ventilation holes 11e of the frame 11 overlapping the space E, and the ventilation holes 12e are formed by arranging a plurality of small holes. is there. Alternatively, the ventilation hole 11e on the frame 11 side may be one in which a plurality of small holes are arranged.

The magnetic circuit A supported by the heat radiating plate 12 includes a ring-shaped yoke 18 and a ring-shaped magnet 19. The yoke 18 is formed of a lightweight magnetic material having a high magnetic permeability such as soft ferrite, is positioned on the step 12a inside the heat sink 12, and is fixed by an adhesive or the like. The magnet 19 is a bonded magnet (plastic magnet) in which a magnetic material (magnet material) is solidified with resin, and the magnet 19 is positioned on the step 12b outside the heat sink 12 and fixed by an adhesive or the like. .

A mounting member 21 made of a nonmagnetic material such as aluminum, an aluminum alloy, or a synthetic resin is provided above the yoke 18, which is a member of the magnetic circuit A. And the heat sink 12
A mounting screw 22 is inserted through the mounting hole 12c formed in the center of the mounting member 2 and the mounting screw 22
It is screwed to 1 and tightened. With this tightening force,
The yoke 18 is firmly fixed.

The bobbin 17 and the coils C1 and C2
Is inserted into a gap between the yoke 18 and the magnet 19. The portion of the magnet 19 facing the coil C1 is magnetized to the N-pole, and the portion facing the coil C2 is magnetized to the S-pole.
The electromagnetic current acts on the coils C1 and C2 due to the voice current flowing through the diaphragm 2, and the diaphragm 13 is vibrated.

In this loudspeaker, the heat generated in the coils C1 and C2 is radiated from the heat radiating plate 12 to the outside through the members constituting the magnetic circuit A or through the space. Since the heat radiating plate 12 is formed of a material having a high thermal conductivity such as aluminum, sufficient heat radiation from the heat radiating plate 12 to the external space is performed. In the embodiment of FIG.
The heat sink 12 has a large area in the cylindrical hole 11d at the bottom of
Are exposed, a sufficient heat radiation effect is obtained by the heat radiation plate 12.

Further, with the vibration of the vibration plate 13 and the damper 16 or by the convection of air, the air flows through the ventilation hole 12 e formed in the heat radiation plate 12 and the ventilation hole 11 e of the frame 11 in the space around the magnetic circuit A. The air in a certain space E is ventilated, so that the heat around the magnetic circuit A can be released to the outside. The space E communicates with the outside air only through the ventilation holes 12e in which a plurality of small holes are arranged, but in the ventilation holes 11e in which a plurality of small holes are formed, external dust and dirt enter the space E. Hard to perform, so the magnetic circuit A
The structure is such that dust and the like hardly adhere to the gap portion of the.

Since the yoke 18 and the magnet 19 constituting the magnetic circuit A are supported on the metal radiator plate 12 with sufficient rigidity, the supporting strength is increased. Further, the mounting member 21 is tightened by the mounting screw 22, but since the tightening is supported by the metal heat radiating plate 12, the durability by the tightening can be sufficiently exhibited.

In the magnetic circuit A, the coils C1, C1,
A yoke 18 is provided inside C2 and a magnet 19 is provided outside. On the contrary, the magnet 19 is provided inside the coils C1 and C2, and the yoke 18 is provided outside.
The magnet 19 may be pressed and supported by the magnet. In the above embodiment, the speaker having the cone-shaped diaphragm 13 has been described as an example. However, the sound vibration of the diaphragm may be of a type that vibrates the space in the horn.

[0030]

As described above, according to the present invention, in a lightweight speaker in which the frame is made of synthetic resin, a heat radiating plate made of a non-magnetic material is provided at the base of the frame. It is possible to prevent the coil from being damaged by heat. Further, since the heat sink is a non-magnetic material, it does not affect the magnetic field of the magnetic circuit.

Further, since the members (pole pieces) constituting the magnetic circuit are supported by the metal radiator plate, the supporting strength of the members constituting the magnetic circuit is increased. Further, when the mounting member is fastened with a screw to fix a member constituting the magnetic circuit, a metal radiator plate is used for mounting, so that damage to the frame due to the tightening of the screw does not occur.

[Brief description of the drawings]

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

2 (A) is a plan view, FIG. 2 (B) is a longitudinal sectional view, and FIG. 2 (B) is a view showing a heat sink used in the speaker shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Frame 11e Ventilation hole 12 Heat sink 12a, 12b Step 12c Mounting hole 12e Ventilation hole 13 Diaphragm 15 Dome 16 Damper 17 Bobbin 18 Yoke 19 Magnet A Magnetic circuit B Magnetic circuit storage space C1, C2 Coil E Magnetic circuit Space

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04R 9/02 101 H04R 9/02 102 B29C 45/14 H04R 9/00

Claims (3)

(57) [Claims] 1. A speaker in which a diaphragm, a coil for applying vibration to the diaphragm, and a magnetic circuit for applying a magnetic field to the coil are provided in a frame, wherein the frame is formed of a synthetic resin material. A loudspeaker, wherein a radiator plate made of a nonmagnetic metal material is attached to an inner surface of the base, and a member constituting a magnetic circuit is attached to the radiator plate. 2. The speaker according to claim 1, wherein a hole communicating with each other is formed in the radiator plate and the frame, and a space inside and outside the frame is connected through the hole. 3. The loudspeaker according to claim 1, further comprising a mounting member for pressing a member constituting the magnetic circuit from the diaphragm side, wherein the mounting member is fixed to the heat sink with screws.