WO2019098181A1

WO2019098181A1 - Sound production device

Info

Publication number: WO2019098181A1
Application number: PCT/JP2018/041949
Authority: WO
Inventors: 大志沼田; 大悟青木; 明広土屋
Original assignee: アルプスアルパイン株式会社
Priority date: 2017-11-16
Filing date: 2018-11-13
Publication date: 2019-05-23
Also published as: JP2021016020A

Abstract

This sound production device comprises: a vibration plate; an armature made of a magnetic material; a pair of magnets that face each other, sandwiching the armature, and form a prescribed gap therebetween; a yoke that supports the pair of magnets; a coil; and a transmission body that transmits the vibration of the armature to the vibration plate. The yoke has an accommodation unit in which a portion of the armature fits, in the direction where the prescribed gap was formed, and the armature is retained in the accommodation unit. Such a sound production device ensures stability in total harmonic distortion, enables reduction in the quantity of materials used for the armature, and allows for reduced device size.

Description

Pronunciation device

TECHNICAL FIELD The present invention relates to a sound generating device that generates sound by driving a diaphragm by vibration of an armature.

In the electro-acoustic transducer described in Patent Document 1, an armature, a yoke, a coil, a pair of magnets, and the like are disposed in a housing, the armature includes an armature movable portion, and in the movable direction of the armature movable portion, A movable foil member or wire member is provided in at least one of the space formed by the armature movable portion and the inner circumferential surface of the coil.

The electromagnetic transducer described in Patent Document 2 comprises (1) permanent magnet means for forming a magnetic flux field extending in the direction between the magnetic pole faces disposed on both sides of the working space; 3) An elongated armature extending through the coil and supported at one end, the other end extending into the working space, said other end being oscillatory in the direction between the pole faces An armature configured to be connected to the diaphragm, and (4) a snapper means fixed relative to the magnet means to control displacement in a direction perpendicular to the direction between the pole faces of the armature And a snapper means having a surface.

JP, 2007-074499, A JP 2004-529767 A

Generally, in order to stabilize total harmonic distortion (THD) in a sounding device, it is necessary to accurately arrange an armature at a central position between a pair of magnets. On the other hand, in the electro-acoustic transducer described in Patent Document 1, the inner surface of the side plate portion of the armature is fixed to the outer surface of the yoke by welding or bonding, thereby adjusting the position of the armature It is possible. Further, in the electromagnetic transducer described in Patent Document 2, the outer arm of the armature is supported by a bridge portion, and the bridge portion is integrally formed with a wing portion or a pad welded to the magnet piece by welding or the like. The position of the armature can be adjusted by this.

However, since the armature of Patent Document 1 and the armature of Patent Document 2 are laterally enlarged, there is a problem that the yield of the material cut out from the flat plate is low.

Furthermore, in the armature of Patent Document 1, the side plate portion is fixed to the outer surface of the yoke, and in the armature of Patent Document 2, the bridge portion supporting this is integrated with the wing portion or the pad to be a magnet piece It is fixed to the outside surface of the Therefore, since the side plate portion, the wing portion or the pad is enlarged laterally, it is difficult to reduce the size of the side as the sound generating device.

Therefore, an object of the present invention is to provide a sound generation device which can save the material used for the armature while securing the stability of the total harmonic distortion, and can reduce the size of the device.

In order to solve the above-mentioned problems, in the sound generation device of the present invention, a diaphragm, an armature formed of a magnetic material, a pair of magnets facing each other with a predetermined space between the armatures, and a pair of magnets , A coil, and a transmission body for transmitting the vibration of the armature to the diaphragm, the yoke having a housing portion in which a part of the armature is fitted in a direction forming a predetermined gap, the housing portion Is characterized in that the armature is held.

According to such a configuration, a part of the armature is accommodated in the accommodating portion provided in the yoke in the direction in which the pair of magnets form the predetermined interval with the armature interposed therebetween. As a result, since the armature can be moved in the direction in which the predetermined interval is formed in the housing portion, the armature can be adjusted at the time of aligning the center position between the pair of magnets. Then, the aligned armature can be fixed as it is to the inside or the periphery of the housing by adhesion or welding. Therefore, the armature can be accurately disposed at the center between the pair of magnets, whereby the total harmonic distortion can be stabilized. Furthermore, since it is not necessary to provide the armature with a fixed portion to the side of the yoke as in the conventional sound emitting device, it is possible to save the armature material by that amount and to miniaturize the device in the side direction of the yoke. Become. Further, since the arrangement of the armature can be performed with high accuracy, the tolerance of the component parts can be relaxed, thereby reducing the manufacturing cost.

In the sound generation device of the present invention, the housing portion may be a concave portion which is recessed in a direction in which a predetermined distance is formed in the yoke. In addition, at least a pair of convex portions may be provided in the yoke so as to protrude in a direction in which a predetermined distance is formed and to face each other, and a housing portion may be formed between the convex portions that face each other.
Thus, by providing the housing portion by the concave portion or the convex portion and setting the depth (height) appropriately, it is possible to simply provide an adjustment margin for disposing the armature at the central position between the pair of magnets. .

According to the present invention, it is possible to provide a sound generation device capable of saving the material used for the armature while securing the stability of the total harmonic distortion, and capable of downsizing the device.

FIG. 1 is a perspective view showing a configuration of a sound generation device according to an embodiment of the present invention. It is a disassembled perspective view of the sound production apparatus shown in FIG. It is sectional drawing in the III-III 'line | wire of FIG. FIG. 4 is a cross-sectional view taken along line IV-IV ′ of FIG. 3; It is a perspective view which shows the positional relationship of a magnetic field generation unit and an armature. FIG. 6 is a front view showing a state in which the armature 51 is assembled to the magnetic field generation unit 30 and the bobbin 40.

Hereinafter, the sound generation device according to the embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing the configuration of a sound generation device 11 according to the present embodiment, and FIG. 2 is an exploded perspective view of the sound generation device 11. FIG. 3 is a cross-sectional view taken along line III-III 'of FIG. FIG. 4 is a cross-sectional view taken along line IV-IV 'of FIG. FIG. 5 is a perspective view showing the positional relationship between the magnetic field generation unit 30 and the armature 51. As shown in FIG. FIG. 6 is a front view showing a state in which the armature 51 is assembled to the magnetic field generation unit 30 and the bobbin 40. As shown in FIG.

In the following description, the vertical direction (Z direction) in each drawing is the vertical direction or the height direction, the sound generation nozzle 15 side in the Y direction in FIG. 2 is the front side, and the substrate 16 side is the rear side. Is referred to as the left and right direction, respectively. In addition, each direction can be arbitrarily determined according to the attitude | position of the sound-producing apparatus of this invention. In addition, the state when looking from the upper side to the lower side along the vertical direction may be referred to as a plan view.

As shown in FIG. 1, the sound producing device 11 has a case 12. As shown in FIGS. 1 and 2, the case 12 is composed of a lower case 13 and an upper case 14. The lower case 13 and the upper case 14 are formed by die casting using a resin material or a nonmagnetic material or a magnetic metal material. Alternatively, it is formed by pressing using a nonmagnetic or magnetic metal plate.

As shown in FIG. 2, the lower case 13 has a bottom 13a, a side wall 13b surrounding four side surfaces, and an open end 13c at the upper end of the side wall 13b. The upper case 14 has a ceiling 14a, side walls 14b surrounding four side surfaces, and an open end 14c at the lower end of the side wall 14b. The inner space of the lower case 13 is wider than the inner space of the upper case 14, and the upper case 14 functions as a lid of the lower case 13. The open end 13 c of the lower case 13 and the open end 14 c of the upper case 14 have substantially rectangular shapes corresponding in shape to each other in plan view. The lower case 13 and the upper case 14 are arranged such that the positions of the

open ends

13c and 14c in plan view coincide with each other, and are fixed by welding the

open ends

13c and 14c to each other by laser welding ( Figure 3, Figure 4). By fixing in this manner, the component members accommodated in the lower case 13 and the component members accommodated in the upper case 14 are positioned in a predetermined relationship.

As shown in FIG. 2, the diaphragm 21 is formed of a thin metal material such as aluminum or SUS304, and ribs 21 d for enhancing the bending strength are press-formed as needed. The flexible sheet 22 is more likely to be bent and deformed than the diaphragm 21 and is formed of, for example, a resin sheet (resin film) such as PET (polyethylene terephthalate), nylon, or polyurethane.

The diaphragm 21 is adhered and fixed to the lower surface of the flexible sheet 22, and the outer peripheral edge 22 a of the flexible sheet 22 is adhered and fixed to the inner surface 14 e of the upper case 14 by the adhesive film 23. As a result, the vibrating plate 21 is supported by the upper case 14 so as to be able to vibrate via the flexible sheet 22.

The vibrating plate 21 can vibrate so that the free end 21 b is displaced in the Z direction with the fulcrum side end 21 c as a fulcrum by bending and elasticity of the flexible sheet 22.

As shown in FIG. 3, a magnetic field generation unit 30 is disposed in the lower case 13. The magnetic field generation unit 30 has an upper yoke 31 and a lower yoke 32. The upper yoke 31 and the lower yoke 32 are formed of a magnetic material, and are formed of, for example, a steel plate such as a cold-rolled steel plate represented by SPCC, a Ni-Fe alloy, or the like.

As shown in FIG. 4, the upper yoke 31 has an inner surface 31 a on the lower side in the Z direction and a bonding surface 31 b on the upper side in the Z direction. As shown in FIG. 5, the bonding surface 31 b is a pair of

convex portions

31 c and 31 d provided so as to extend along the Y direction at both end portions in the X direction, and the pair of

convex portions

31 c and 31 d in the X direction. And a recessed portion 31e (accommodating portion) recessed downward in the Z direction. In other words, the pair of

convex portions

31c, 31d extend in parallel with each other, and the concave portion 31e is a direction (Z Z) in which the upper magnet 34 and the lower magnet 35 form a predetermined interval D1 (FIG. 5) In the direction), it is recessed downward. Further, as shown in FIG. 4, the recess 31e and the inner surface 31a face each other in parallel in the Z direction.

The concave portion 31e is integrally formed with the pair of

convex portions

31c and 31d using a mold having a corresponding projecting shape. Alternatively, first, the bonding surface 31b is formed in a planar shape, and a pair of

convex portions

31c and 31d are formed at both ends in the X direction of the plane, thereby forming the concave portion 31e between the pair of

convex portions

31c and 31d. You may make it form. In this case, the pair of

convex portions

31c, 31d can be manufactured, for example, by plating the planar bonding surface 31b. Alternatively, members corresponding to the pair of

convex portions

31c, 31d may be separately manufactured and fixed on the planar joint surface 31b by welding or adhesion.

The height of the recess 31 e in the Z direction is preferably the same as the thickness in the Z direction of the fixing portion 51 b of the armature 51 or larger than the thickness of the fixing portion 51 b. When the fixing portion 51b is moved along the Z direction in the recess 31e as shown by the arrow A in FIG. 6 by making the thickness larger than the thickness of the fixing portion 51b, the fixing portion 51b is a pair of convex portions 31c. , 31d can be arranged so as not to project upward in the Z direction.

As shown in FIG. 5, the pair of

convex portions

31 c and 31 d respectively extend along the Y direction and has a substantially rectangular shape in a plan view along the Z direction, but is not limited to this planar shape. For example, the pair of

convex portions

31c and 31d may be divided into a plurality in the Y direction, and the shapes of the plurality of divided convex portions may be rectangular or elliptical in plan view. The pair of

convex portions

31c and 31d shown in FIG. 5 extends to a position corresponding to the outer side surface of the side surface portion 32b of the lower yoke 32 in the X direction, but the distance D2 between the inner surfaces of the two

convex portions

31c and 31d As long as the width (see FIG. 6) corresponds to the width of the fixing portion 51b, the outer surface in the X direction may be in a more elongated planar shape positioned inside the side surface portion 32b of the lower yoke 32.

As shown in FIGS. 2 and 4, the lower yoke 32 is bent in an open U-shape, and includes a bottom portion 32a and a pair of side portions 32b bent upward on both sides in the X direction. . The upper end portion of the side surface portion 32b is joined to the inner surface 31a of the upper yoke 31, and the upper yoke 31 and the lower yoke 32 are fixed to each other by laser spot welding or the like. When the upper yoke 31 and the lower yoke 32 are fixed, the inner surface 32 c of the bottom surface 32 a of the lower yoke 32 and the inner surface 31 a of the upper yoke 31 face each other in parallel. The width dimension of the upper yoke 31 is formed such that both end portions in the X direction protrude on both sides of the outer surface on both sides of the side surface portion 32 b of the lower yoke 32.

As shown in FIG. 4, in the magnetic field generating unit 30, the upper magnet 34 is fixed to the inner surface 31 a of the upper yoke 31, and the lower magnet 35 is fixed to the inner surface 32 c of the bottom portion 32 a of the lower yoke 32. In the Z direction, a gap g having a predetermined distance D1 is formed between the lower surface 34a of the upper magnet 34 and the upper surface 35a of the lower magnet 35. The upper magnet 34 and the lower magnet 35 are magnetized so that the lower surface 34a of the upper magnet 34 and the upper surface 35a of the lower magnet 35 have opposite polarities.

As shown in FIGS. 2 and 3, a coil 37 is provided at a position aligned with the magnetic field generation unit 30. The coil 37 is wound around the bobbin 40 such that the conducting wire revolves around a winding axis extending in the Y direction. The bobbin 40 is formed of a resin material of nonmagnetic material.

As shown in FIG. 2 and FIG. 3, the end face of the bobbin 40 facing the front side is a bonding surface 41 as the abutted portion, and this bonding surface 41 is the upper yoke 31 and the lower yoke 32 of the magnetic field generating unit 30. Is fixed to the back surface 30a facing in the Y direction with an adhesive or the like. At this time, the winding center line of the coil 37 is positioned so as to coincide with the center of the gap g between the upper magnet 34 and the lower magnet 35 and fixed to each other.

The bobbin 40 includes a space 42 in which the winding center line of the coil 37 is included, and the movable portion 51 a of the armature 51 is inserted into the space 42. Accordingly, the lead of the coil 37 is wound around the movable portion 51 a of the armature 51. Further, the winding axis of the coil 37 substantially coincides with the center of the space 42 of the bobbin 40 in the Z direction.

As shown in FIGS. 2 and 3, the end portion 38 of the wire of the coil 37 extends rearward from the back surface 43 of the bobbin 40.

As shown in FIGS. 2 to 4, the sound producing device 11 is provided with an armature 51. The armature 51 is formed of a plate of magnetic material, and is formed of, for example, a Ni--Fe alloy. The armature 51 is pressed and bent into a U-shape having a movable portion 51a, a fixed portion 51b and a bent portion 51c. The movable portion 51a and the fixed portion 51b face each other in parallel at an interval in the Z direction. As shown in FIG. 2, the width dimension of the tip portion 51 d of the movable portion 51 a of the armature 51 facing in the Y direction is smaller than the width dimension of the movable portion 51 a in the X direction.

As shown in FIGS. 4 and 5, the fixing portion 51b of the armature 51 is fitted in the recess 31e of the joint surface 31b of the upper yoke 31, and is fixed to the joint surface 31b by welding or adhesion. Further, as shown in FIG. 3, the movable portion 51 a of the armature 51 is inserted into the space 42 of the bobbin 40, and is further inserted into the gap g between the upper magnet 34 and the lower magnet 35. The end 51 d of the armature 51 extends from the inside of the gap g to the front in the Y direction.

Here, the pair of

convex portions

31c, 31d in the X direction is formed such that the distance D2 (see FIG. 6) of the inner surface thereof is substantially the same as the width in the X direction of the fixing portion 51b of the armature 51. It is done. Thereby, the fixing portion 51b can be fitted into the recess 31e. The movable portion 51a of the armature 51 in the Z direction also moves in the direction of the arrow A by moving the fixed portion 51b fitted in the recess 31e up and down along the Z direction, that is, along the direction of the arrow A shown in FIG. To move the center of the movable part 51a to the centers of the two

magnets

34, 35. In a state where the center of the movable portion 51a and the centers of the two

magnets

34, 35 coincide with each other, the fixed portion 51b is fixed to the joint surface 31b by welding or adhesion. This fixing is performed, for example, by welding or bonding both end surfaces 51 bc and 51 bd in the X direction of the fixing portion 51 b to the pair of

convex portions

31 c and 31 d. Also, instead of or in addition to this, a thermosetting or photocurable adhesive is applied in advance between the fixing portion 51b and the recess 31e, and after the position adjustment of the armature 51, adhesion is performed. The agent may be cured.

As shown in FIG. 3, the free end 21 b of the diaphragm 21 and the tip 51 d of the armature 51 are connected by the transmission body 52. The transmission body 52 is a member formed of metal or synthetic resin, and is formed of, for example, a SUS 202 pin material. The upper end 52a of the transmission body 52 is inserted into a mounting hole 21e formed in the diaphragm 21, and is further inserted into a hole 22e provided in the flexible sheet 22 above the mounting hole 21e in the Z direction. . The diaphragm 21 and the flexible sheet 22 and the transmission body 52 are fixed to each other by an adhesive.

The lower end portion 52 b of the transmission body 52 is fixed to the tip end surface 51 e of the tip portion 51 d of the armature 51 by laser welding, adhesion, or soldering.

The holder 60 as a support member is formed of a metal plate material of nonmagnetic material having a uniform thickness dimension. As shown in FIG. 2, in the holder 60, both ends in the left-right direction (X direction) of the bottom plate 61 are bent upward in the vertical direction (Z direction) to form a pair of side wall parts facing each other. The side wall includes a pair of left and right first side walls 62a and a pair of left and right second side walls 62b. The first side wall 62a and the second side wall 62b are continuous in the longitudinal direction (Y direction), and the height in the vertical direction is higher in the first side wall 62a than in the second side wall 62b. ing.

When the magnetic field generating unit 30 is disposed at a predetermined position on the front side in the holder 60 as shown in FIG. 3, both outer side surfaces of the side surface portion 32b of the lower yoke 32 are paired in the left and right direction as shown in FIG. The magnetic field generation unit 30 is held by the holder 60 by being in contact with the first side wall portions 62 a as holding portions. In the front-rear direction, the back surface 30a of the upper yoke 31 and the lower yoke 32 facing in the Y direction is fixed to the joint surface 41 of the bobbin 40 with an adhesive or the like and is positioned thereby (see FIG. 3). Further, as shown in FIG. 2, two wiring holes 13e are provided at positions corresponding to the pair of end portions 38 of the coil 37, which extend from the bobbin 40, in the upper portion of the rear side wall portion 13b. There is.

By arranging the holder 60 in the lower case 13, the holder 60 is incorporated in a state of being positioned in the lower case 13. By this positioning, the two end portions 38 extended from the back surface 43 of the bobbin 40 are respectively extended from the two wiring holes 13 e of the side wall portion 13 b to the outside.

The upper case 14 in which the diaphragm 21 and the flexible sheet 22 are disposed, the magnetic field generation unit 30, the armature 51, the transmission body 52, and the holder 60 holding the bobbin 40 on which the coil 37 is wound When the arranged lower case 13 is fixed to each other, the space inside the case 12 is divided up and down by the diaphragm 21 and the flexible sheet 22. A space above the diaphragm 21 and the flexible sheet 22 and inside the upper case 14 is a sound emission side space, and the sound emission side space is a sound emission port 14 d formed in the side wall portion 14 b on the front side of the upper case 14. It leads from the outside space. As shown in FIGS. 2 and 3, on the outside of the front of the case 12, a sound producing nozzle 15 communicating with the sound producing port 14d is fixed.

As shown in FIGS. 2 and 3, a pair of wiring holes 13 e is opened in the rear side wall 13 b of the lower case 13, and a pair of end portions 38 extending from the back surface 43 of the bobbin 40 is a pair. They are respectively drawn out from the wiring holes 13e. The substrate 16 is fixed to the outside of the rear side wall portion of the case 12, the terminal portion 38 passes through the small hole formed in the substrate 16, the small hole is closed by soldering, and the outer periphery of the substrate 16 is resin The wiring hole 13e is closed from the outside by sealing with the.

The assembly operation of the sound generation device 11 is as follows.
As shown in FIG. 3 and FIG. 4, the sound producing device 11 is fixed so that the upper case 14 and the lower case 13 in which the respective parts are incorporated are matched with each other at the open ends 13 c and 14 c in plan view. Ru. In the upper case 14, the diaphragm 21 and the flexible sheet 22 are positioned and fixed. In the lower case 13, after positioning the bobbin 40 with respect to the holder 60, the magnetic field generation unit 30, the armature 51 and the transmission body 52 are respectively positioned, and the holder 60 in this state is further positioned with respect to the lower case 13. It is positioned.

On the upper case 14 side, as shown in FIGS. 3 and 4, the diaphragm 21 is overlapped and joined to the lower surface of the flexible sheet 22, and the outer peripheral edge 22 a of the flexible sheet 22 is the inner surface of the upper case 14. 14e (see FIG. 3) is disposed at a predetermined position and adhesively fixed by an adhesive film 23.

For the lower case 13 side, as shown in FIG. 3 and FIG. 4, first, the upper magnet 34 is joined to the inner surface 31 a of the upper yoke 31, and the lower magnet 35 is attached to the inner surface 32 c (upper surface) of the bottom surface 32 a of the lower yoke 32. The upper yoke 31 and the lower yoke 32 are fixed by laser spot welding or the like to assemble the magnetic field generation unit 30.

Next, the bobbin 40 is assembled to the holder 60. The coil 37 is wound around the bobbin 40 in advance so that the conducting wire revolves around a winding axis extending in the Y direction.

Subsequently, the magnetic field generation unit 30 is assembled to the holder 60 to which the bobbin 40 is assembled. In the magnetic field generation unit 30, the lateral side in the left and right direction of the side surface part 32b contacts the pair of first side wall parts 62a of the holder 60 (see FIG. 4). 31 is inserted into the holder 60 so that the back surface 30a of the lower yoke 32 is in contact (see FIG. 3).

The armature 51 is formed by press processing, and the bending portion 51c is processed so that the movable portion 51a and the fixed portion 51b can face in parallel or substantially in parallel in the Z direction. Then, after inserting the movable portion 51 a into the space 42 of the bobbin 40 and the gap g of the magnetic field generation unit 30, the fixed portion 51 b is fitted into the recess 31 e of the joint surface 31 b which is the upper surface of the upper yoke 31. Subsequently, the entire armature 51 is moved up and down by moving the fixed portion 51 b up and down (direction along arrow A in FIG. 6) in the recess 31 e, and the thickness direction of the movable portion 51 a of the armature 51 (Z direction The fixing portion 51b is fixed to the joint surface 31b by welding or bonding where the center of the) coincides with the centers of the two

magnets

34, 35. Thereby, the armature 51 is fixed to the magnetic field generation unit 30. The fixing portion 51b is fixed, for example, by laser spot welding both end surfaces 51bc and 51bd in the X direction of the fixing portion 51b to the pair of

convex portions

31c and 31d.

Next, the lower end 52 b of the transmission body 52 is fixed to the tip end surface 51 e of the tip 51 d of the armature 51 by laser welding, adhesion, or soldering. By the above process, the bobbin 40 in which the coil 37 is wound, the magnetic field generation unit 30, the armature 51, and the structure in which the transmission body 52 is positioned are formed with respect to the holder 60. Subsequently, the structure is accommodated in the lower case 13. As a result, the two end portions 38 extended from the back surface 43 of the bobbin 40 are extended to the outside from the two wiring holes 13 e of the side wall 13 b of the lower case 13.

Next, the upper case 14 and the lower case 13 in which the respective components are incorporated as described above are fixed so that the

open end portions

13c and 14c thereof coincide with each other in plan view. Fixing is performed by laser spot welding or bonding. Further, the upper end 52a of the transmission body 52 is inserted into the attachment hole 21e formed in the diaphragm 21, and is further inserted into the hole 22e provided in the flexible sheet 22 located above the attachment hole 21e. . The diaphragm 21 and the flexible sheet 22 and the transmission body 52 are fixed by adhesive or soldering.

Here, the lower case 13 is formed by enlarging the attachment holes 21 e formed in the diaphragm 21 and the holes 22 e provided in the flexible sheet 22 so as to form a gap with the transmission body 52. When the upper case 14 is coupled, the transmission body 52 can be attached without performing relative position adjustment in the Y direction.

Finally, the wiring hole 13 e of the lower case 13 is covered with the substrate 16, and the terminal portion 38 of the coil 37 extended from the wiring hole 13 e of the lower case 13 is soldered to the substrate 16. Further, on the front surface of the upper case 14, the sound producing nozzle 15 is fixed at a position corresponding to the sound producing port 14d, and the assembly is completed.

Next, the operation of the sound generation device 11 will be described.
The operation of the sound generator 11 induces a magnetic field in the armature 51 when a voice current is applied to the coil 37. Vibration in the Z direction is generated in the movable portion 51 a of the armature 51 by the magnetic field induced by the armature 51 and the magnetic field generated in the gap g between the upper magnet 34 and the lower magnet 35. This vibration is transmitted to the diaphragm 21 via the transmission body 52. At this time, the vibrating plate 21 supported by the flexible sheet 22 vibrates by swinging the free end 21 b in the Z direction with the supporting end 21 c as a supporting point. Sound pressure is generated in the sound generation space inside the upper case 14 by the vibration of the diaphragm 21, and this sound pressure is output from the sound generation port 14d to the outside through the sound generation nozzle 15.

In the sound generation device 11, since the armature 51 is U-shaped and the fixing portion 51b is long in the Y direction, a portion of the fixing portion 51b not fixed to the upper yoke 31 also functions as a vibrating portion. Therefore, it is possible to lengthen the free length of the vibrating portion and to increase the sounding energy in the low tone range.

Since it was comprised as mentioned above, according to the sound production apparatus 11 of the said embodiment, the direction (Z direction) in which a pair of

magnets

34 and 35 formed the predetermined space | interval D1 on both sides of the movable part 51a of the armature 51 in between. The fixing portion 51 b of the armature 51 is accommodated in the recess 31 e (accommodating portion) provided in the upper yoke 31. Thereby, the armature 51 can be moved in the direction in which the predetermined interval D1 is formed in the recess 31e as the housing portion. For this reason, it is possible to make adjustment when aligning the movable portion 51a of the armature 51 at the central position between the pair of

magnets

34, 35. Then, the aligned armature 51 is directly fixed by adhesion or welding to the inside (inner wall) of the recess 31 e or the peripheral edge of the recess 31 e (the ridge of the recess 31 e and the pair of

protrusions

31 c and 31 d or its periphery) be able to. Therefore, the armature 51 can be accurately disposed at the center position between the pair of

magnets

34 and 35, whereby the total harmonic distortion can be stabilized. Furthermore, in the sound generation device 11 of the present embodiment, unlike the conventional sound generation device, there is no need to provide a fixed portion to the side surface of the yoke in the armature, so that the armature material can be saved accordingly. The device can be miniaturized in the direction (X direction).
Although the present invention has been described with reference to the above embodiment, the present invention is not limited to the above embodiment, and can be improved or changed within the scope of the improvement purpose or the spirit of the present invention.

As described above, the sound generation device according to the present invention is useful in that it can save the material used for the armature and can be miniaturized.

DESCRIPTION OF SYMBOLS 11 sound production apparatus 12 case 13 lower case 13a bottom part 13b side wall part 13c opening end 13e wiring hole 14 upper case 14a ceiling part 14b side wall part 14c opening end part 14d sounding opening 14e inner surface 15 pronunciation nozzle 16 substrate 21 diaphragm 21b free end

21c Fulcrum end 21d rib

21e mounting hole 22 flexible sheet 22a outer peripheral edge 22e hole 23 adhesive film 30 magnetic field generating unit 30a rear surface 31 upper yoke 31a inner surface

31b bonding surface

31c, 31d convex portion 31e concave portion (housing portion)
32 lower yoke 32a bottom portion 32b side surface portion 32c inner surface 34 upper magnet 34a lower surface 35 lower magnet 35a upper surface 37 coil 38 terminal portion 40 bobbin 41 joint surface 42 space 43 rear surface 51 armature 51a movable portion 51b fixed portion 51bc, 51bd end face of fixed portion 51c bent portion 51d tip portion 51e tip end surface 52 transmitter 52a upper end 52b lower end 60 holder (supporting member)
61 bottom plate 62a first side wall portion (sandwich portion)
62b Second side wall (holding part)
D1 Predetermined interval D2 Interval between two projections

Claims

A diaphragm,
An armature formed of a magnetic material,
A pair of magnets facing each other with a predetermined distance between the armatures;
A yoke supporting the pair of magnets;
With the coil,
And a transmitter for transmitting the vibration of the armature to the diaphragm.
The yoke has a housing portion in which a part of the armature fits in the direction in which the predetermined interval is formed,
A sound producing apparatus characterized in that the armature is held in the housing portion.
The sound producing apparatus according to claim 1, wherein the housing portion is a concave portion which is recessed in a direction in which the predetermined interval is formed in the yoke.
The sound producing apparatus according to claim 1, wherein at least a pair of convex portions are provided in the yoke so as to protrude in a direction forming the predetermined interval and to be opposed to each other, and the accommodating portion is formed between the convex portions opposed to each other. .