JP3429624B2 - Case structure of surface mount type electromagnetic sounding body - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic sounding body that produces a sound by vibrating a diaphragm with an electromagnet, and more particularly to a case structure capable of maximizing the diameter of the diaphragm. .

[0002]

2. Description of the Related Art Among conventional electromagnetic sounding bodies, the surface-mounting type electromagnetic sounding body, which has been particularly reduced in size and thickness, has a structure as shown in FIGS. That is, in the surface mount type electromagnetic sounding body shown in FIGS. 7 and 8, the lower case 2
Both the upper case 4 and the upper case 4 have a rectangular planar shape, and after the respective components are housed in the lower case 2, the upper case 4 is covered and joined. The lower case 2 is provided with a circular recess 2a in the upper two-thirds portion in FIG. 7, and is provided with a rectangular recess 2b in the substantially lower one-third portion. ing. The portions other than the recesses 2a and 2b are thick wall portions 2c. In the concave portion 2a of the lower case 2, a yoke 10 having a coil 8 attached to the center thereof is arranged, a ring-shaped magnet 12 is arranged so as to surround the coil 8, and a ring-shaped vibration is further provided outside thereof. A plate support frame 14 is arranged. The vibrating plate support frame 14 has a step portion 14a formed on an upper portion thereof, and the vibrating plate 16 is supported by the step portion 14a. On the other hand, the electrode 18 is exposed in the recess 2b, and the terminal of the coil 8 is connected thereto. In this electromagnetic sounding body, the entire outer circumference of the diaphragm support frame 14 is the inner circumference of the concave portion 2a, that is, the wall portion 2.
The structure is positioned and held by contacting c, and the upper case 4 is externally fitted to the outer side of the lower case 2.

On the other hand, in the surface mount type electromagnetic sounding body shown in FIGS. 9 and 10, the substrate 2 which also functions as a lower case.
A diaphragm supporting frame 2 having a shape adapted to the substrate 22
4 and a yoke 26 integrated and insert-molded in the center of the diaphragm support frame 24, a coil 28 is attached to the center of the yoke 26, and a ring-shaped magnet 30 is arranged around the coil 28. Annular protrusion 2 of support frame 24
4a, the vibration plate 32 is placed, and the upper case 34
It was a structure to cover.

[0004]

In the surface mount type electromagnetic sounding body, which is desired to be further reduced in size and thickness, as the size of the sounding body becomes smaller along with the outer shape,
There was a problem that the sound pressure was reduced. For this reason,
In order to increase the sound pressure even a little, it was necessary to downsize only the case and make the diaphragm as large as possible.

However, in the conventional surface mount type electromagnetic sounding body shown in FIGS. 7 and 8, the thick wall portion 2c is used.
Due to the structure in which the diaphragm support frame 14 is held all around, and the upper case 4 is externally fitted to the outer side of the lower case 2, the upper surface of the diaphragm support frame 14 is separated from the outer surface of the upper case 4.
It was structurally difficult to reduce the distance to the outer surface of the. Therefore, in order to downsize the upper and lower cases 2 and 4, the diaphragm 16 must be downsized, and if the diameter of the diaphragm 16 is increased, the upper and lower cases 2 and 4 must be upsized. .

Further, in the surface mount type electromagnetic sound producing body shown in FIGS. 9 and 10, in order to regulate the lateral displacement of the vibration plate 32, an annular projection 34 is formed on the inner upper surface of the upper case 34.
a is provided, and the protrusion 34a is used for the diaphragm support frame 2
The annular protrusion 24a of No. 4 and the side surface on the inner side of the upper case 34 are configured to be inserted. Therefore, it is necessary to provide a space between the annular protruding portion 24a of the diaphragm support frame 24 and the inner side surface of the upper case 34, and this space hinders downsizing of the case or upsizing of the diaphragm. There was a problem.

The present invention has been made in view of the problems of the above-described conventional example, and an object thereof is surface mounting which enables the diameter of the diaphragm to be maximized without increasing the outer shape of the case. The purpose of the present invention is to provide a case structure for a type electromagnetic sounding body.

[0008]

A case structure of a surface mount type electromagnetic sound producing body of the present invention is a surface mount type electromagnetic sound producing body which produces a sound by vibrating a diaphragm supported by a diaphragm supporting ring by an electromagnet. A lower case having a plurality of projecting walls projecting from a corner portion of the inner bottom surface and positioning and holding the diaphragm support ring from the outer peripheral side; and an upper case fitted to the lower case.

Further, the case structure of the surface mount type electromagnetic sound producing body of the present invention is such that, in the surface mount type electromagnetic sound producing body which produces a sound by vibrating the diaphragm supported by the diaphragm supporting ring by the electromagnet, on the inner bottom surface. A lower case on which the diaphragm support ring is placed, and the diaphragm support formed by being fitted to the lower case at a position corresponding to a corner portion of an inner bottom surface of the lower case. And an upper case having a plurality of protruding walls for positioning and holding the ring from the outer peripheral side.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the case structure of the surface mount type electromagnetic sound producing body of the present invention, a plurality of protruding walls for positioning and holding the diaphragm support ring from the outer peripheral side are provided at the corners of the inner bottom surface of the lower case. There is. When the plane shape of the lower case is rectangular or polygonal, a gap is created between the outer peripheral surface of the ring-shaped diaphragm support ring and the corner of the lower case. In the present invention, the protruding wall is provided at the corner portion where this gap is generated, and the diaphragm supporting ring is positioned and held by the protruding wall. Therefore, it becomes possible to bring the inner side surfaces of the lower case other than the corners and the diaphragm support ring as close as possible, and the diameter of the diaphragm can be maximized.

Further, by providing a projecting wall on the inner upper surface of the upper case corresponding to the corner portion of the lower case, and covering the lower case with the upper case, the diaphragm support ring housed in the lower case is attached to the upper case. Modifications can be made to position and hold the protruding wall.

[0012]

1 is a plan view showing a state in which an upper case and a vibration plate of a surface mount type electromagnetic sound generator according to an embodiment of the present invention are removed, and FIGS. 2 and 3 are C-C and D thereof. It is a -D sectional view. Reference numeral 40 is a lower case made of plastic or the like, and has a bottom 40a having a rectangular or polygonal planar shape.
A side wall 40b protruding upward from the peripheral edge thereof, and a bottom portion 4
And a protruding wall 40d protruding from the inner bottom surface 40c of 0a. The bottom portion 40a in this embodiment is formed so as to have an octagonal planar shape in which four corners of a quadrangle are cut off. Further, the protruding wall 40d is an inner bottom surface 40c of a corner portion 42 formed between a corner portion of the bottom portion 40a and the side wall 40b and a diaphragm support ring described later.
More prominent. The protruding wall 40d in this embodiment is
The inner peripheral surface 40e is formed of a curved surface that fits a diaphragm support ring, which will be described later, and is formed at each of the four corner portions 42. The protruding wall 40d protrudes higher than the side wall 40b and a diaphragm support ring described later, and as shown in FIG. 3, a step 40f is formed between the protruding wall 40d and the side wall 40b. Its height is equal to the side wall 40b. Further, the protruding wall 40d also restricts the radial movement of the diaphragm described later.

Reference numeral 46 denotes a yoke having a disk shape and a pole formed in the center thereof, and is housed in the center of the lower case 40. A coil 44 is attached to the center of the yoke 46, and its ends are connected to electrodes 48 and 50 that are insert-molded when the lower case 40 is formed. A C-shaped magnet 52 is provided outside the coil 44, and a diaphragm support ring 54 is provided outside the magnet 52.
Is provided. The vibrating plate support ring 54 includes a vibrating plate 55 mounted on the upper end of the vibrating plate support ring 54, a yoke 46, and a coil 44.
And a protruding wall 40d of the lower case 40, which supports the electromagnet composed of the magnet 52 and the magnet 52 so as to face the electromagnet.
Is positioned and held from the outer peripheral side. In this embodiment, the disc-shaped portion 46a of the yoke 46 is also positioned by the protruding wall 40d so that the inner bottom surface 4 of the lower case 40 is
It is fixed at 0c.

Reference numeral 56 denotes an upper case, which is composed of a lid portion 56a having the same planar shape as the bottom portion 40a of the lower case 40, and a side wall 56b protruding from the peripheral edge thereof.
A protrusion 56 d protruding downward is provided on the inner upper surface 56 c of the lid portion 56 a of the upper case 56, and the vibrating plate 55 is provided.
The position is restricted to above. This upper case 56 is
It is fitted onto the protruding wall 40d of the lower case 40, and further, the side wall 56
When the lower surface portion of b and the upper surface portion of the side wall 40b of the lower case 40 are engaged, the step portion 40f is also engaged. Here, the engaging portions on the peripheral edge of the case are joined by ultrasonic welding or adhesion, and the lower case 40 and the upper case 56 are fixedly integrated.

In the surface mount type electromagnetic sounding body having the above structure, the diameter of the diaphragm 55 can be increased until the outer periphery of the diaphragm 55 is inscribed in the side wall 40b of the lower case 40. In order to maximize the diameter of the diaphragm 55 as described above, it is necessary to increase the diaphragm support ring 54 to have substantially the same diameter. In this way, even when the diaphragm 55 and the diaphragm support ring 54 are set to the maximum diameter,
The corner portion of the side wall 40b of the lower case 40 and the diaphragm support ring 5
A gap is always formed in the corner portion 42 between the corner portion 42 and the corner 4, and the protruding wall 40d is formed in the corner portion 42 thus generated as a wasteful space. Therefore, the protruding wall 40 that positions and holds the diaphragm support ring 54
It is not necessary to provide a special space for forming d, and the diaphragm 55 and the diaphragm support ring 54 are attached to the side wall 40b.
It is possible to increase the size until it touches.

In this embodiment, the projecting walls 40d of the lower case 40 are formed at four places, but when the shape of the lower case 40 is changed to a quadrangle or another polygon, it matches the shape. You may increase or decrease the number like this.

4 to 6 are views showing a partially modified example of the case structure shown in FIG. 1 and the like, and FIG. 4 is a plan view showing a state in which the upper case of the surface mount type electromagnetic sounding body and the vibration plate are removed. ,
5 is a plan view of the upper case as seen from below, and FIG. 6 is a plan view of FIG.
FIG. In this modification, a protruding wall 56e is provided on the inner upper surface 56c of the upper case 56 instead of the protruding wall 40d provided on the lower case 40. The projecting wall 56e in the present modification has the same shape as the projecting wall 40d described above, and is provided between the corners of the bottom surface 40a and the side surface 40b of the lower case 40 on the inner upper surface 56c and the diaphragm support ring 54. The formed corner portion 42
Is formed at a position corresponding to. Also, this protruding wall 5
6e projects downward so as to be higher than the side wall 56b,
As shown in FIG. 6, a step portion 56f is formed between the protruding wall 56e and the side wall 56b, and its height is set to be equal to that of the side wall 56b. As described above, in this modified example, the projecting wall 56e is provided on the upper case 56, and the operation / effect and the structure of each part other than the projecting wall 56e are the case structures shown in FIGS. Is the same as.

[0018]

According to the present invention, since the diaphragm support ring is positioned and held by providing the protruding walls at the corners of the lower case or the upper case, the diaphragm can be enlarged to the full extent in the case. The sound pressure characteristic can be improved without increasing the size of the case. On the contrary, the case can be further downsized without deteriorating the sound pressure characteristic.

Further, since one of the upper case and the lower case can be positioned and held by externally fitting the protruding wall of the other, a step portion and other structures for positioning and holding the upper case and the lower case can be provided. Since it is not particularly necessary to provide the structure, the structures of the upper case and the lower case can be made as simple as possible, the yield can be improved by improving the moldability and the assemblability, and the man-hours such as the die machining maintenance can be reduced.

Further, the surface mount type electromagnetic sounding body having the structure as shown in the embodiment using the C-shaped magnet is originally of a structure suitable for miniaturizing the outer shape. By adopting the present invention on the body, and by further forming the upper and lower cases into a shape with four corners cut off,
It is possible to reduce interference with other electronic components on the board on which the surface mount type electromagnetic sounding body is mounted, and it is possible to realize high density mounting.

Furthermore, according to the present invention, the structure for enabling automatic mounting such as taping is maintained,
It is smaller and can maximize the sound pressure.

Further, since the diaphragm can be positioned in the radial direction by the protruding wall provided on the upper case or the lower case, the upper surface shape of the diaphragm supporting ring on which the diaphragm is placed is complicated as in the conventional case. Since it is not necessary to form a shape that has undergone various steps such as chamfering and chamfering, and a flat surface is sufficient, the number of processing steps can be reduced and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view showing a state in which an upper case and a vibration plate of a surface-mounted electromagnetic speaker according to an embodiment of the present invention are removed.

FIG. 2 is a cross-sectional view showing a state in which an upper case and a diaphragm are mounted in a cross section on the CC cross section of the surface-mounted electromagnetic speaker shown in FIG.

FIG. 3 is a cross-sectional view showing a state in which an upper case and a diaphragm are mounted on the DD cross section of the surface-mounted electromagnetic speaker shown in FIG.

FIG. 4 is a plan view showing a state in which a part of the surface mount type electromagnetic sounding body shown in FIG. 1 and the like is changed and an upper case and a diaphragm are removed.

5 is a plan view of the upper case of the surface-mounted electromagnetic sounding body shown in FIG. 4 as viewed from below.

6 is a cross-sectional view showing a state in which an upper case and a diaphragm are placed on the EE cross section of the surface-mounted electromagnetic speaker shown in FIG.

FIG. 7 is a plan view showing a state in which an upper case and a diaphragm of a conventional surface mount type electromagnetic sounding body are removed.

8 is a cross-sectional view showing a state in which an upper case and a diaphragm are placed on the AA cross section of the surface-mounted electromagnetic sounding body shown in FIG.

FIG. 9 is a plan view showing a state in which an upper case of another conventional surface mount type electromagnetic sounding body is removed.

10 is a cross-sectional view showing a state in which an upper case is placed in a cross section on the BB cross section of the surface-mounted electromagnetic speaker shown in FIG.

[Explanation of symbols]

40 lower case 40a bottom 40b side wall 40c inner bottom 40d protruding wall 40e inner peripheral surface 42 Corner 44 coils 46 York 48, 50 electrodes 52 magnet 54 Vibration plate support ring 55 diaphragm 56 upper case 56a lid 56b side wall 56e protruding wall 56c Internal upper surface

Claims (7)

(57) [Claims] 1. A surface mount type electromagnetic sounding body which generates a sound by vibrating a diaphragm supported by a diaphragm support ring with an electromagnet, wherein the diaphragm support ring protrudes from a corner portion of an inner bottom surface and the diaphragm support ring is provided from an outer peripheral side. A case structure for a surface-mounted electromagnetic sound generator, comprising: a lower case having a plurality of protruding walls for positioning and holding, and an upper case fitted to the lower case. 2. The case of a surface mount type electromagnetic sound producing body according to claim 1, wherein the upper case is positioned by being fitted onto a projecting wall of the lower case and fitted into the lower case. Construction. 3. The surface mount electromagnetic device according to claim 1, wherein the projecting wall of the lower case restricts the radial movement of the diaphragm by being located near the outer periphery of the diaphragm. Case structure of the sounding body. 4. A surface mount type electromagnetic sounding body which generates a sound by vibrating a diaphragm supported by a diaphragm support ring with an electromagnet, and a lower case on which the diaphragm support ring is mounted on an inner bottom surface. A plurality of protruding walls which are formed on the inner upper surface at positions corresponding to the corners of the inner bottom surface of the lower case and which are fitted to the lower case to position and hold the diaphragm support ring from the outer peripheral side. A case structure for a surface-mounted electromagnetic speaker, which comprises an upper case and a case. 5. The protruding wall of the upper case is positioned by being fitted between the side wall of the lower case and the diaphragm support ring, and is fitted to the lower case. 4. The case structure of the surface-mounted electromagnetic speaker according to 4. 6. The planar shape of the upper case and the lower case
5. The polygonal shape according to claim 1 or 4,
Case structure of surface mount type electromagnetic sounding body. 7. The corners of the upper case and the lower case
Having an external shape that looks like the outside of the part is cut off
The case of the surface-mounted electromagnetic speaker according to claim 6, characterized in that
Structure.