JP3554877B2 - Electromagnetic sounding body - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electromagnetic sounding body that generates a sound by vibrating a diaphragm with an electromagnet, and particularly relates to a device that supports a diaphragm with a diaphragm support ring.
[0002]
[Prior art]
As this type of conventional electromagnetic sounding body, there is one having a structure shown in FIG. This electromagnetic sounding body is of a surface mounting type mounted on the surface of a circuit board by reflow soldering or the like. An electromagnet is placed in a box-shaped case 6 formed by joining the upper case 2 and the lower case 4. 8, the diaphragm supporting ring 10 and the diaphragm 12 were housed.
[0003]
The electromagnet 8 includes a yoke 14, a coil 16 having terminals connected to external terminals 18 and 20 attached to the yoke 14 and drawn out of the case 6, and a magnet 22 provided around the coil 16. Was composed. Further, the diaphragm supporting ring 10 is disposed outside the magnet 22, and the outer peripheral surface and the lower surface thereof are fixed by being bonded to the inner wall of the case 6 and the yoke 14, respectively. Further, the diaphragm 12 is supported in a vibrable state by mounting the outer peripheral portion on the diaphragm supporting ring 10.
[0004]
[Problems to be solved by the invention]
In the conventional electromagnetic sounding body having the above configuration, when the diaphragm supporting ring 10 is bonded, the adhesive rises in the gap between the diaphragm supporting ring 10 and the case 6 due to a capillary phenomenon, and the diaphragm supporting ring In some cases, the diaphragm 12 that reaches the upper surface of the ring 10 and is placed thereon is fixed to the diaphragm supporting ring 10 and the case 6. When the vibration plate 12 is fixed in this way, the vibration is suppressed, so that there is a problem that the generated sound is reduced. Such an increase in the adhesive due to the capillary phenomenon may occur even when the adhesive for fixing the diaphragm support ring 10 is melted by the heat of the reflow solder during surface mounting, and improvement is desired. Was.
[0005]
When the gap between the diaphragm supporting ring 10 and the inner wall of the case 6 is increased to solve the above problem, the size of the case 6 is increased, and the diameter of the diaphragm 12 together with the diaphragm supporting ring 10 is reduced. Or it is necessary to change the fixing structure of the diaphragm support ring 10 to a more complicated structure, and it is expected that new problems will be caused in terms of integration into a circuit board, volume and cost. Was.
[0006]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the related art, and an object of the present invention is to provide an electromagnetic sounding body that can suppress an increase in an adhesive for fixing a diaphragm support ring while minimizing structural changes. To provide.
[0007]
[Means for Solving the Problems]
The electromagnetic sounding body of the present invention is an electromagnetic sounding body that generates sound by vibrating a diaphragm supported by a diaphragm support ring with an electromagnet, wherein an annular groove, unevenness, or a concave portion is formed on an outer peripheral surface of the diaphragm support ring. It is provided with a convex portion.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
In the electromagnetic sounding body of the present invention, the outer peripheral surface of the diaphragm supporting ring that supports the diaphragm has an annular groove formed along the outer periphery, fine irregularities formed by honing, or a plurality of concaves or convexes. Part is provided. By providing such an annular groove or the like, even if the adhesive for fixing the diaphragm support ring starts to rise in the gap between the outer peripheral surface of the diaphragm support ring and the inner side wall of the case due to the capillary phenomenon, the bonding is performed. The agent stops accumulating due to the action of accumulating in the annular groove or the like, and does not rise until it reaches the diaphragm.
[0009]
【Example】
FIG. 1 is a sectional view showing the structure of an electromagnetic sounding body according to one embodiment of the present invention, FIG. 2 is an enlarged sectional view of the diaphragm supporting ring, and FIG. 3 is a perspective view thereof.
[0010]
This electromagnetic sounding body has basically the same structure as the above-mentioned conventional electromagnetic sounding body. That is, the electromagnetic sounding body of the present embodiment has a box-shaped case 36 formed by joining the upper case 32 and the lower case 34, and the electromagnet 38, the diaphragm support ring 40, and the diaphragm housed therein. 42. The electromagnet 38 includes a yoke 44 composed of a plate-like portion 44a and a rod-like portion 44b erected at the center thereof, and external terminals 48, 50 attached to the outer periphery of the rod-like portion 44b and drawn out of the case 36. And a magnet 52 having a ring shape or a C shape attached to the plate-shaped portion 44a of the yoke 44 at a constant interval outside the coil 46. .
[0011]
On the other hand, the diaphragm supporting ring 40 is made of metal, heat-resistant plastic, or the like, and has an outer peripheral surface provided with an annular groove 40a which is a feature of the present invention. The annular groove 40a is formed by performing automatic lathe processing or the like along the outer periphery of the diaphragm supporting ring 40, and in the present embodiment, a plurality of annular grooves 40a are arranged in the height direction. Is formed. The inner and outer diameters of the diaphragm support ring 40 are set such that they can be fixed to the outside of the magnet 52 at a fixed interval and fixed to the inner wall of the case 36 with an adhesive. The diaphragm 42 has an outer peripheral portion mounted on the diaphragm supporting ring 40 so as to face the electromagnet 38, and is positioned by being attracted by the magnet 52.
[0012]
In the electromagnetic sounding body of the present embodiment having the above-described configuration, the entire periphery of the upper surface of the plate-like portion 44a of the yoke 44 with which the lower corner portion 40b of the diaphragm support ring 40 abuts or the inner wall of the lower case 34 After the adhesive is applied to the entire lower periphery, the diaphragm supporting ring 40 is assembled into the lower case 34. Thus, the lower surface of the diaphragm support ring 40 is adhered to the plate-shaped portion 44 a of the yoke 44, and the outer peripheral surface is adhered to the inner wall of the lower case 34. Thereafter, the diaphragm 42 is placed on the diaphragm support ring 40, and the upper case 32 is joined to the lower case 34. As described above, when the diaphragm supporting ring 40 is incorporated into the lower case 34 and when the upper case 32 is joined to the lower case 34, the adhesive is applied between the diaphragm supporting ring 40 and the case 36 by capillary action. Spread in the gap. However, in the present embodiment, when the adhesive reaches the annular groove 40a, it will accumulate here. Therefore, the progress of the adhesive stops, and the adhesive does not rise and reach the diaphragm 42. Similarly, when the adhesive for fixing the diaphragm support ring 40 is melted due to the heat of the reflow solder or the like, the melted adhesive stops rising at the annular groove 40a. Will never be reached.
[0013]
As described above, since the annular groove 40a is for stopping the progress of the adhesive due to the capillary phenomenon, the width of the groove is increased so that the progress can be stopped, and furthermore, as shown in FIG. It is desirable to form a plurality of them.
[0014]
The annular groove 40a may have a V-shaped cross section as shown in FIG. 2, or may have a U-shape as shown in FIG. May be formed in a U-shape as shown in FIG. Further, the position where the annular groove 40a is formed may be formed over the entire area in the height direction of the outer periphery as shown in FIG. 2, or one or several lines may be formed above the outer periphery as shown in FIG. Then, the adhesive may be surely prevented from rising before the diaphragm 42.
[0015]
FIG. 8 is a side view showing a modification of the diaphragm support ring 40 of the electromagnetic sounding body shown in FIG. On the outer peripheral surface of the diaphragm supporting ring 40, fine irregularities 40c are formed over the entire area, and the outer peripheral surface has a so-called Riko ground outer peripheral surface. The fine irregularities 40c are formed by honing or the like. By providing the fine irregularities 40c on the outer peripheral surface of the diaphragm support ring 40 in this manner, the resistance between the outer peripheral surface of the diaphragm support ring 40 and the adhesive increases, and the rise of the adhesive due to the capillary phenomenon is prevented. can do. Incidentally, even if the unevenness 40c is relatively large, a pool of the adhesive can be formed, so that the rise of the adhesive can be similarly prevented. When the diaphragm support ring 40 is formed of plastic, the unevenness 40c can be formed at the time of molding.
[0016]
9 and 10 are cross-sectional views showing another modification of the diaphragm support ring 40 of the electromagnetic sounding body shown in FIG. A plurality of concave portions 40d or convex portions 40e are formed on the entire outer peripheral surface of the diaphragm supporting ring 40. By forming the concave portion 40d or the convex portion 40e in this manner, the adhesive rising due to the capillary phenomenon can be accumulated in the concave portion 40d or between the inner wall of the case 36 and the surface around the convex portion 40e. The rise of the agent can be prevented.
[0017]
【The invention's effect】
According to the present invention, since the annular groove or the like is provided on the outer periphery of the diaphragm support ring, the adhesive for fixing the diaphragm support ring is prevented from rising in the gap between the diaphragm support ring and the case. The diaphragm can be prevented from being fixed by the rising adhesive. For this reason, a highly reliable electromagnetic sounding body can be provided.
[0018]
In addition, since there is no need to significantly change the shape, size, structure, and the like, there is no occurrence of a new problem or an increase in cost due to the change in structure.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a structure of an electromagnetic sounding body according to one embodiment of the present invention.
FIG. 2 is an enlarged sectional view of the diaphragm support ring shown in FIG.
FIG. 3 is a perspective view of a diaphragm support ring shown in FIG. 2;
FIG. 4 is a sectional view showing another sectional shape of the annular groove shown in FIG. 2;
FIG. 5 is a sectional view showing another sectional shape of the annular groove shown in FIG. 2;
FIG. 6 is a sectional view showing another sectional shape of the annular groove shown in FIG. 2;
FIG. 7 is a cross-sectional view showing another example of the formation position of the annular groove shown in FIG.
FIG. 8 is a side view showing a modified example of the diaphragm support ring of the electromagnetic sounding body shown in FIG.
FIG. 9 is a sectional view showing another modification of the diaphragm support ring of the electromagnetic sounding body shown in FIG. 1;
FIG. 10 is a sectional view showing another modification of the diaphragm support ring of the electromagnetic sounding body shown in FIG. 1;
FIG. 11 is a sectional view showing the structure of a conventional electromagnetic sounding body.
[Explanation of symbols]
6, 36 Case 8, 38 Electromagnet 10, 40 Diaphragm support ring 12, 42 Diaphragm 40a Annular groove 40c Concavo-convex 40d Recess 40d Convex

Claims (5)

In an electromagnetic sounding body that generates sound by vibrating a diaphragm supported by a diaphragm support ring with an electromagnet,
An electromagnetic sounding body, wherein an annular groove is provided on an outer peripheral surface of the diaphragm supporting ring. 2. The electromagnetic sounding body according to claim 1, wherein a plurality of said annular grooves are provided. In an electromagnetic sounding body that generates sound by vibrating a diaphragm supported by a diaphragm support ring with an electromagnet,
An electromagnetic sounding body, wherein irregularities are formed on the entire outer peripheral surface of the diaphragm supporting ring. 4. The electromagnetic sounding body according to claim 3, wherein the irregularities are finely formed by honing. In an electromagnetic sounding body that generates sound by vibrating a diaphragm supported by a diaphragm support ring with an electromagnet,
A plurality of concave portions or convex portions are formed on the entire outer peripheral surface of the diaphragm supporting ring.

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