JP2021034864A - Acoustic device - Google Patents

Abstract

To provide an acoustic device structured to prevent peeling from a case, destruction of a vibrator, etc., caused by a deformation of the vibrator and a tension.SOLUTION: An acoustic device comprises a main body case and a speaker unit which is fixed inside the main body case. The speaker unit includes: a magnetic circuit section 10 including a magnet 11; a coil 20 on which a magnetic field generated in the magnetic circuit section 10 acts; and a vibrator 15 which is vibrated together with the coil 20. With the vibrator 15 defined as a boundary, an internal space A and an external space B of the main body case are defined. A vibrator regulation section 21a is provided at a position at a rear side of the vibrator 15 in a sound generation direction and opposed with the vibrator 15, and the vibrator 15 and the vibrator regulation section 21a are tilted to the rear side in the sound generation direction as they are directed in a central axis direction of the vibrator. Therefore, peeling from a case, destruction of the vibrator, etc., caused by a deformation of the vibrator and a tension is prevented.SELECTED DRAWING: Figure 4

Description

The present invention relates to an audio device having a main body case and a speaker unit.

Generally, a warning sound generating speaker mounted on a vehicle and a speaker provided in a portable electronic device are required to adopt a waterproof structure. This is because water easily enters the speaker in a speaker having low waterproof performance, which causes a failure.

As an example of this technique, Patent Document 1 describes an invention of an acoustic device for the purpose of preventing destruction of a waterproof vibrating membrane due to pressure fluctuation.

The audio device described in Patent Document 1 includes a waterproof vibrating film and a magnetic portion. The waterproof vibrating membrane is molded with a gently uneven curved surface, and the magnetic part corresponds to the shape of the concave part of the waterproof vibrating membrane and the pressure absorbing part of the concave part corresponding to the shape of the convex part of the waterproof vibrating membrane. A pressure-cushioning portion of the convex portion is provided. Even if the waterproof diaphragm is pressurized by flooding and the waterproof diaphragm is pressed against the magnetic part, the shape of the molded curved surface of the waterproof diaphragm is protected and the waterproof diaphragm can be prevented from being destroyed. It is a thing.

JP-A-2018-50141

In the invention described in Patent Document 1, the formed curved surface shape of the waterproof vibrating membrane located above the magnetic portion can be protected by the pressure buffer portion of the magnetic portion. However, on the outer peripheral side of the voice coil, a pressure buffer portion facing the molded curved surface shape of the waterproof vibrating membrane is not provided, and the waterproof vibrating membrane is not protected, so that the waterproof vibrating membrane is deformed and pulled by pressure. At that time, it may not be possible to prevent the case from peeling off or the waterproof vibrating membrane from being destroyed.

The present invention solves the above-mentioned conventional problems, and even if the vibrating body is deformed and pulled due to a sudden fluctuation of pressure or the like, the vibrating body is peeled off from the case or the vibrating body is destroyed. It is an object of the present invention to provide an acoustic device having a structure capable of preventing the vibration.

In the present invention, a main body case and a speaker unit fixed inside the main body case are provided, and the speaker unit is a coil in which a magnetic circuit portion including a magnet and a magnetic field generated in the magnetic circuit portion act. And a vibrating body that vibrates with the coil.
The internal space and the external space of the main body case are partitioned by the vibrating body as a boundary, and the vibrating body regulating unit is located at a position opposite to the sounding direction of the vibrating body and facing the vibrating body. Is provided.

In the audio device of the present invention, it is preferable that the vibrating body regulating portion has a shape that imitates the vibrating body. For example, the vibrating body and the vibrating body regulating portion are inclined rearward toward the central axis direction of the vibrating body.

The vibrating body of the audio device of the present invention is
It has an edge portion formed on the outer peripheral side of the vibrating body and a diaphragm portion formed on the inner peripheral side of the vibrating body.
It is preferable that the vibrating body regulating portion is arranged so as to face the edge portion.

The speaker unit of the audio device of the present invention includes a bobbin that supports the coil and vibrates together with the vibrating body, a bracket that supports the magnetic circuit portion and is fixed to the main body case, and the bobbin and the bracket. It has a damper provided between the two, and a damper regulating portion arranged behind the damper.
The distance that the coil moves from the neutral position to the position where the damper hits the damper regulating portion is preferably smaller than the distance that the coil moves from the neutral position to the position where the diaphragm hits the diaphragm regulating portion.

The vibrating body regulating portion of the audio device of the present invention is, for example, a surface facing rearward of the regulating portion forming member fixed to the bracket.

The bracket of the audio device of the present invention has a bracket inner bottom portion formed on the inner peripheral side of the bracket and a bracket outer bottom portion formed on the outer peripheral side of the bracket, and the bracket outer bottom portion is inside the bracket. It is preferable that the damper is formed in front of the bottom portion in the sounding direction, and the damper is sandwiched between the regulating portion forming member and the bracket outer bottom portion.

The vibrating body restricting portion of the audio device of the present invention can be integrally formed with the bracket.

The acoustic device of the present invention has a configuration in which a vibrating body regulating unit is provided at a position facing the vibrating body at the rear, which is the direction opposite to the sounding direction of the vibrating body. Therefore, it is possible to prevent the joint portion between the vibrating body and the bracket from peeling off when the vibrating body is deformed and pulled due to a sudden change in pressure or the like.

The perspective view which shows the appearance of the audio apparatus of embodiment of this invention. In the audio apparatus shown in FIG. 1, an exploded perspective view showing a main body case and a speaker unit. An exploded perspective view of the speaker unit shown in FIG. The cross-sectional view which shows the cross-sectional part of the acoustic apparatus shown in FIG. 1 from the front. The half sectional view explaining the operation of the speaker unit of this invention. The half sectional view for demonstrating the problem which the speaker unit of a comparative example has.

The acoustic device 1 of the embodiment of the present invention shown in FIG. 1 is for in-vehicle use, and is required not to be destroyed even when the vehicle is flooded. In the sound device 1, the Y1 direction is the front facing the sounding direction, and the Y2 direction is the rear facing the sounding direction. 1 and 4 show a center line O extending in the sounding direction.

The audio device 1 has a main body case 2. As shown in FIGS. 1 and 2, the main body case 2 is separated into a front case 3 and a rear case 4. As shown in FIGS. 1 and 4, the rear end portion of the front case 3 and the front end portion of the rear case 4 are fitted together, and the concave-convex fitting portions 5 provided at a plurality of locations together with the front case 3. The rear case 4 and the rear case 4 are fixed to each other. The front case 3 and the rear case 4 are formed by injection molding using a synthetic resin material or die casting molding using a light metal material. As shown in FIG. 1, a plurality of openings 3a and partition portions 3b for partitioning the respective openings 3a are formed on the front portion of the front case 3 facing forward. As shown in FIG. 4, a small vent 4b is formed at the bottom of the rear case 4 facing rearward. The front side (Y1 direction) of the vent portion 4b is closed by the membrane member 23 that comes into contact with the vent portion 4b. The membrane member 23 is made of a material that allows air to pass through but does not allow water to pass through.

As shown in FIGS. 2 and 4, the speaker unit 6 is provided inside the front case 3. As shown in FIGS. 3 and 4, the speaker unit 6 includes a bracket 7 formed of a non-magnetic or magnetic metal plate, and is formed on the outer diameter side of the bracket 7 shown in FIGS. 2 and 3. The bracket bent surface portion 7a is fixed to the inner surface of the front case 3 with screws 9. As shown in FIG. 5, a bracket inner bottom 7b perpendicular to the center line O and a bracket outer bottom 7c are formed at the rear end of the bracket 7, and the bracket outer bottom 7c is forward (Y1 direction) from the bracket inner bottom 7b. ) Is located.

The magnetic circuit portion 10 is fixed to the lower surface of the inner bottom portion 7b of the bracket facing rearward (Y2 direction). As shown in FIGS. 4 and 5, the magnetic circuit unit 10 is placed in front of the magnet 11 (Y1 direction) with the lower yoke 12 to which the magnet 11 and the lower surface facing the rear side (Y2 direction) of the magnet 11 are joined. It is composed of an upper yoke 13 to which the upper surface facing is joined, and the upper surface facing the front of the upper yoke 13 is adhered and fixed to the lower surface facing the rear (Y2 direction) of the inner bottom portion 7b of the bracket 7. .. The lower yoke 12 and the upper yoke 13 are made of a magnetic material. A center pole portion 12a projecting forward (in the Y1 direction) is integrally formed in the central portion of the lower yoke 12, and the outer peripheral surface of the center pole portion 12a and the inner peripheral surface of the ring-shaped upper yoke 13 are formed. A magnetic gap G is formed between them.

The vibrating body 15 is provided in front of the magnetic circuit unit 10 (in the Y1 direction). The vibrating body 15 is composed of a diaphragm portion 16 and an edge portion 17. The bending rigidity of the edge portion 17 with the axial direction of all virtual axes facing the plane perpendicular to the center line O as the curvature direction is lower than the bending rigidity of the diaphragm portion 16 in the same direction. The edge portion 17 is formed of rubber, urethane, or cloth impregnated with rubber. The flexural rigidity is the product of the Young's modulus E and the moment of inertia of area I. The outer peripheral portion 16a of the diaphragm portion 16 is adhered to the edge portion 17. As shown in FIGS. 4 and 5, the outer end portion 17a of the edge portion 17 is adhered and fixed to the bracket 7 to form a joint portion (a). The edge portion 17 is adhered to and fixed to the diaphragm portion 16 to form a joint portion (b). The outer peripheral surface of the bobbin 18 is adhered and fixed to the inner peripheral portion 16b of the diaphragm portion 16 to form a joint portion (c).

The diaphragm portion 16 of the vibrating body 15 has a cone shape, and has a tapered shape that inclines toward the rear (Y2 direction) toward the center line O. Specifically, as shown in FIG. 5, the taper angle α of the diaphragm portion 16, that is, the angle formed by the diaphragm portion 16 with respect to the plane perpendicular to the center line O is set in the range of 20 ° to 60 °. There is. The taper of the vibrating plate portion 16 has a taper whose diameter changes linearly with respect to a distance, a taper whose diameter changes exponentially with respect to a distance, or a diameter whose diameter is proportional to the square root of the distance from the tip, and the entire shape is a parabola. It is formed by any of the tapers that

As shown in FIGS. 3 and 4, the regulating portion forming member 21 is provided at a position behind the edge portion 17 (in the Y2 direction) and facing the edge portion 17, and is fixed to the bracket 7. The regulating portion forming member 21 is formed by injection molding using a synthetic resin material or die casting molding using a light metal material.

The regulating portion forming member 21 includes a vibrating body regulating portion 21a facing the edge portion 17. The vibrating body regulating portion 21a has a shape that follows the shape of the vibrating body 15 that faces the vibrating body, and is inclined so as to imitate the shape. In the embodiment, the vibrating body regulating unit 21a is a vibrating body regulating surface that is inclined rearward (Y2 direction) toward the center line O. That is, the vibrating body regulating portion 21a has a tapered shape. Specifically, as shown in FIG. 5, the taper angle β of the vibrating body regulating portion 21a, that is, the angle formed by the vibrating body regulating portion 21a with respect to the plane perpendicular to the center line O is set in the range of 5 ° to 75 °. Has been done. The taper of the vibrating body regulating portion 21a is a taper whose diameter changes linearly with respect to a distance, a taper whose diameter changes exponentially with respect to a distance, or a diameter whose diameter is proportional to the square root of the distance from the tip, and the overall shape is changed. It is formed by one of the tapers that becomes a parabola.

The vibrating body regulating portion 21a and the vibrating plate portion 16 constituting the vibrating body 15 are tilted in the same direction, and the difference between the taper angle α of the vibrating plate portion 16 and the taper angle β of the vibrating body regulating portion 21a is 0. It is set in the range of ° to 15 °. It is desirable that the difference between the taper angle α of the diaphragm portion 16 and the taper angle β of the vibrating body regulating portion 21a is small.

As shown in FIG. 4, a damper 19 having a corrugated cross section is provided between the outer peripheral surface of the bobbin 18 and the bracket 7. The cone-shaped diaphragm portion 16 can vibrate in the front-rear direction (Y1-Y2 direction) due to the elastic deformation of the edge portion 17 and the damper 19. A coil 20 is wound around the lower end portion of the bobbin 18 facing rearward, and the coil 20 is located in the magnetic gap G. The center line O is a virtual line that passes through the winding center of the coil 20, the center of the damper 19, and the center of the vibrating body 15, and further passes through the center of gravity of the magnetic circuit unit 10. The damper 19 is sandwiched between the regulation portion forming member 21 and the bracket outer bottom portion 7c formed on the outer peripheral side of the bracket 7. As a result, the space for fixing the damper 19 and the bracket 7 can be used as the installation space for the regulating portion forming member 21, and the damper 19 is further sandwiched between the regulating portion forming member 21 and the bracket 7. Therefore, the fixing force between the damper 19 and the bracket 7 can be increased.

As shown in FIG. 5, a damper regulating portion 22 is arranged behind the damper 19 (in the Y2 direction). The damper regulating unit 22 means a place where at least a part of the damper 19 first hits when the vibrating body 15 in the neutral position moves rearward (in the Y2 direction). In the present embodiment, the damper regulating portion 22 is a front-facing surface portion of at least one of the bracket 7 or the upper yoke 13. The distance D1 in which the coil 20 moves from the neutral position to the position where the damper 19 hits the damper regulating portion 22 is smaller than the distance D2 in which the coil 20 moves from the neutral position to the position where the vibrating body 15 hits the vibrating body regulating portion 21a.

Inside the rear case 4, a circuit board 8 on which electronic components are mounted and other members are housed.

Next, the sounding operation of the sound device 1 will be described.
When a current is applied to the coil 20, the vibrating body 15 vibrates in the front-rear direction (Y1-Y2 direction) due to the electromagnetic force excited by the magnetic field and the current acting on the coil 20 in the magnetic circuit unit 10, and the sound pressure is generated. It is given in front of the sounding direction (Y1 direction). In normal sounding operation, the maximum distance to move the vibrating body 15 in the neutral position and the bobbin 18 to the rear (Y2 direction) is restricted to the amount of movement until at least a part of the damper 19 hits the damper regulating portion 22. .. The distance D1 (see FIG. 5) in which the coil 20 moves from the neutral position of the damper 19 to the position where the damper 19 hits the damper regulating portion 22 is the distance that the coil 20 moves from the neutral position to the position where the vibrating body 15 hits the vibrating body regulating portion 21a. Since it is smaller than D2, even if the damper 19 moves until it hits the damper regulating portion 22, the vibrating body 15 does not hit the vibrating body regulating portion 21a, and the presence of the vibrating body regulating portion 21a does not interfere with the normal sounding operation. ..

The sound device 1 is divided into a main body case 2 with the vibrating body 15 as a boundary, and is divided into an internal space A partitioned by the lower surface of the vibrating body 15 and the main body case 2, and a partition by the upper surface of the vibrating body 15 and the main body case 2. It is partitioned into the front space and the external space B, which is the space outside the case.

In normal use, in the acoustic device 1, the air in the internal space A and the air in the external space B can freely move in each other's space through the film member 23 and the vent portion 4b, so that the air in the internal space A can move freely. It is possible to make the air pressure equal to the air pressure in the exterior space B.

However, since the sound device 1 is mounted on a car, the temperature may drop sharply after being placed in a high temperature air environment and then being submerged in low temperature water. During flooding, the air in the internal space A and the air in the external space B cannot freely move in each other's space via the membrane member 23. Therefore, when the temperature drops sharply, the air in the internal space A becomes The pressure drops suddenly. Further, it is conceivable that the audio device 1 is moved from the high temperature air environment to the low temperature air environment, and the temperature drops sharply. Even in that case, the inner diameter of the vent portion 4b is extremely small, the flow rate of air is restricted, and the flow rate of air in the vent portion 4b cannot follow a sudden change in the pressure of the internal space A, and is inside. The air pressure in space A suddenly drops.

When the pressure of the air in the internal space A suddenly drops, as shown in FIG. 5, the diaphragm portion 16 and the edge portion 17 in the neutral state (v) are sucked toward the rear (Y2 direction). At this time, when the edge portion 17 hits the vibrating body regulating portion 21a, the rapid movement of the diaphragm portion 16 and the edge portion 17 to the rear is restricted. That is, since the edge portion 17 has a lower flexural rigidity than the diaphragm portion 16, the edge portion 17 tends to reverse toward the rear (Y2 direction) as the pressure in the internal space A drops sharply. As shown in 5, since the edge portion 17 to be inverted hits the vibrating body restricting portion 21a of the regulating portion forming member 21 in the posture of (vi), the inversion can be prevented.

In particular, the vibrating body regulating portion 21a has a tapered surface that inclines in the same direction as the vibrating plate portion 16, and the difference between the taper angle α of the vibrating plate portion 16 and the taper angle β of the vibrating body regulating portion 21a is small, so that the edge The portion 17 is likely to come into surface contact with the vibrating body regulating portion 21a, and the edge portion 17 is likely to be prevented from being inverted. Therefore, even if the pressure in the internal space A decreases, a large force does not act on the edge portion 17, the joint portion (a) between the outer end portion 17a of the edge portion 17 and the bracket 7 is peeled off, and the diaphragm portion 16 and the vibrating plate portion 16. Peeling of the joint portion (b) with the edge portion 17 and peeling of the joint portion (c) between the diaphragm portion 16 and the bobbin 18 are less likely to occur. In addition, the diaphragm portion 16 and the edge portion 17 are less likely to be destroyed.

As a comparative example, FIG. 6 shows an audio device 1 without a regulating portion forming member 21. In this comparative example, when a sudden pressure drop occurs in the air in the internal space A, the edge portion 17 having low rigidity is sucked from the neutral position (i) to the rear (Y2 direction) toward the internal space A. It becomes the inverted state (ii). Following the inversion of the edge portion 17, the diaphragm portion 16 is in a deformed state (iii) bent toward the internal space A. If the edge portion 17 is pulled strongly backward due to a decrease in the internal pressure in the bent deformed state (iii), the outer end portion 17a of the edge portion 17 may be peeled off from the bracket 7. Alternatively, the joint portion between the diaphragm portion 16 and the edge portion 17 and the joint portion between the diaphragm portion 16 and the bobbin 18 are likely to be peeled off.

In the embodiment shown in FIG. 5, since the rearward reversal of the edge portion 17 having low flexural rigidity is restricted, the diaphragm portion 16 is in a bent deformed state (iii) as shown in FIG. It can be regulated, the joint portion (a) between the outer end portion 17a of the edge portion 17 and the bracket 7, the joint portion (b) between the diaphragm portion 16 and the edge portion 17, and the joint portion between the diaphragm portion 16 and the bobbin 18 ( It becomes easy to prevent the peeling of c), and the breakage of the diaphragm portion 16 and the edge portion 17 can be prevented.

As the regulation portion forming member 21 used in the other actual machine form of the present invention, it is conceivable that the regulation portion forming member 21 is integrally formed with the bracket 7. The restricting portion forming member 21 is formed as a throttle portion or a bending portion protruding from the side surface of the bracket 7 in the direction of the center line O. Also in this embodiment, since the regulating portion forming member 21 is provided at a position behind the edge portion 17 (in the Y2 direction) and facing the edge portion 17, deformation of the edge portion 17 is suppressed. Therefore, the joint portion (a) between the outer end portion 17a of the edge portion 17 and the bracket 7, the joint portion (b) between the diaphragm portion 16 and the edge portion 17, and the joint portion (c) between the diaphragm portion 16 and the bobbin 18 ) Can be easily prevented from peeling off, and the diaphragm portion 16 and the edge portion 17 can be prevented from being destroyed.

1 Sound device 2 Main body case 3 Front case 3a Opening 3b Partition 4 Rear case 5 Concavo-convex fitting part 6 Speaker unit 7 Bracket 7a Bracket bending surface 7b Bracket inner bottom 7c Bracket outer bottom 9 Screw 10 Magnetic circuit 11 Magnet 12 Lower Yoke 13 Upper yoke 15 Diaphragm 16 Vibrating plate 17 Edge 18 Bobbin 19 Damper 20 Coil 21 Regulatoring part forming member 21a Vibrating body regulating part 22 Damper regulating part 23 Film member A Internal space B External space D1 Vibrating plate part moving amount D2 Damper regulation part Movement amount G Magnetic gap O Center line

Claims (8)

Body case and
A speaker unit fixed to the inside of the main body case is provided.
The speaker unit is an acoustic device having a magnetic circuit unit including a magnet, a coil on which a magnetic field generated in the magnetic circuit unit acts, and a vibrating body vibrating together with the coil.
The internal space and the external space of the main body case are partitioned by the vibrating body as a boundary.
An acoustic device characterized in that a vibrating body regulating portion is provided at a position opposite to the sounding direction of the vibrating body and facing the vibrating body. The acoustic device according to claim 1, wherein the vibrating body regulating unit has a shape that imitates the vibrating body. The acoustic device according to claim 2, wherein the vibrating body and the vibrating body regulating portion are inclined rearward toward the central axis direction of the vibrating body. The vibrating body is
It has an edge portion formed on the outer peripheral side of the vibrating body and a diaphragm portion formed on the inner peripheral side of the vibrating body.
The acoustic device according to any one of claims 1 to 3, wherein the vibrating body regulating portion is arranged so as to face the edge portion. The speaker unit is provided between a bobbin that supports the coil and vibrates together with the vibrating body, a bracket that supports the magnetic circuit portion and is fixed to the main body case, and the bobbin and the bracket. It has a damper and a damper regulating part arranged behind the damper.
The distance that the coil moves from the neutral position to the position where the damper hits the damper regulating portion is smaller than the distance that the coil moves from the neutral position to the position where the vibrating body hits the vibrating body regulating portion according to claims 1 to 4. The acoustic device according to any one. The acoustic device according to claim 5, wherein the vibrating body regulating portion is a surface facing forward of the regulating portion forming member fixed to the bracket. The bracket has an inner bottom portion of the bracket formed on the inner peripheral side of the bracket and an outer bottom portion of the bracket formed on the outer peripheral side of the bracket, and the outer bottom portion of the bracket is anterior to the inner bottom portion of the bracket in the sounding direction. Is formed in
The acoustic device according to claim 6, wherein the damper is sandwiched between the regulating portion forming member and the bracket outer bottom portion. The acoustic device according to claim 5, wherein the vibrating body regulating unit is integrally formed with the bracket.

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