JPH0116157Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is designed to excite a diaphragm facing the magnetic pole of the electromagnet with an air gap interposed therebetween by the magnetic interaction between an electromagnet and a permanent magnet. This invention relates to an electromagnetic acoustic transducer. This electromagnetic acoustic transducer can be used in various types of watches, cameras, microwave ovens, and portable devices, for example. video. tape. Used for sound reporting in recorders, pagers, etc.

<Prior Art> This type of electromagnetic acoustic transducer is roughly divided into a bobbin type and a bobbinless type, depending on the magnetic pole that constitutes the electromagnet and the method of winding the coil around the magnetic pole. The bobbin method is a method in which the coil is wound around a bobbin and attached to the magnetic pole, and the bobbinless method is
This method winds the coil directly around the magnetic pole without using a bobbin. FIG. 1 is a cross-sectional view of a conventional electromagnetic acoustic transducer using a bobbin method, and FIG. 2 is a cross-sectional view of a conventional electromagnetic acoustic transducer using a bobbinless method.

First, in the bobbin type shown in FIG.
At the same time, the coil 2 is wound on the bobbin, pin terminals 3 and 4 are planted on one end surface in the axial direction of the bobbin, and the coil terminals 21 and 22 of the coil 2 are tied around the pin terminals 3 and 4 and fixed by soldering, This is fitted and attached to the magnetic pole 5 which together with the coil 2 constitutes an electromagnet. Then, on the upper surface of the yoke 6 on which the magnetic pole 5 is erected, so as to surround the electromagnet consisting of the coil 2 and the magnetic pole 5,
A cylindrical permanent magnet 7 such as a ferrite magnet or a molded plastic magnet is arranged, and a disc-shaped diaphragm 8 is provided on the upper end surface of the permanent magnet 7.
The structure is such that an acoustic transducer is constructed by mounting the acoustic transducer, and this acoustic transducer is attached to the bottom opening of a cylindrical case 9 made of a non-magnetic metal material, synthetic resin, etc. by means such as press fitting. It's summery. 91
is the sound hole.

Next, in the bobbinless type shown in FIG. 2, the coil 2 is directly wound around the magnetic pole 5 without using a bobbin. Coil terminals 21 and 2 of coil 2
2 are soldered and fixed to conductor patterns 11 and 12 on a printed circuit board 10 stacked on the back surface of the yoke 6, and lead to pin terminals 3 and 4 that are soldered and fixed to the conductor patterns 11 and 12. In FIG. 2, the same reference numerals as in FIG. 1 indicate identical components.

<Problems to be solved by the invention> Among the above-mentioned conventional electromagnetic acoustic transducers, the bobbin type shown in FIG. Since the winding structure is similar to that of similar devices, such as transformers, automatic winding is possible by reusing that technology.
It is easy to wind the coil 2, and the bobbin 1
Since the pin terminals 3 and 4 are installed in the
It is possible to assemble the coil terminals 21 and 22 by intertwining them, and there are advantages such as being able to prevent disconnection of the coil terminals 21 and 22, and being able to be mounted on a printed circuit board by means such as a solder dip.

However, since the bobbin 1 is required, there are the following drawbacks.

(a) Since the occupancy rate of the coil 2 is smaller than that of the bobbin 1, the characteristics deteriorate accordingly.

(b) The bobbin 1 must be made of an insulating resin or the like, and its thermal conductivity is inevitably poor, so the heat dissipation for the heat generated by the coil 2 is poor. For this reason, the allowable current capacity of the coil 2 becomes small, making it difficult to obtain a compact electromagnetic acoustic transducer with a large output.

(c) As the bobbin 1 is required, the number of parts increases, the number of assembly steps increases, and the size increases. This type of electromagnetic acoustic transducer has important uses as a sound reporting component in small devices such as wristwatches, and a structure with a large number of parts and a large overall shape is inappropriate.

On the other hand, the bobbinless type shown in FIG. 2 has advantages and disadvantages opposite to those of the bobbin type described above. In other words, since there is no need for a bobbin, the occupancy of the coil 2 is high and the characteristics are improved.The heat dissipation of the heat generated by the coil 2 is good, and the allowable current capacity of the coil 2 is increased. There are advantages such as the converter is easy to obtain, has a small number of parts, is compact, and is suitable as a sound signal component for small devices such as wristwatches. It is not possible to transfer the winding technology for conventional coils, such as transformers, and automatic winding is impossible.

(b) Since a complicated jig is required for winding, wire breakage accidents at the coil terminals 21 and 22 are likely to occur.

(c) As shown in FIG. 2, the coil terminals 21 and 22 are led out through the through holes provided in the yoke 6 and the printed circuit board 10, and then the conductor patterns 11 and 1 on the printed circuit board 10 are drawn out.
Since it is necessary to take measures such as soldering and fixing the coil terminals to 2, processing of the coil terminals is extremely troublesome and automation is almost impossible.

There are other difficulties.

Therefore, the object of the present invention is to eliminate the drawbacks of the two conventional methods mentioned above, and to facilitate the winding process of the coil and the mounting work on the printed circuit board.
It can reliably prevent disconnection accidents at the coil terminals, coil unwinding, and falling off, and it also has a high coil occupancy rate and good characteristics, has good heat dissipation against coil heat generation, has a large allowable current value, and is compact. It is an object of the present invention to provide an electromagnetic acoustic transducer which is easy to obtain, has a large output, is compact, has a small number of parts, and is suitable as a sound reporting component in small devices such as wristwatches.

<Means for Solving the Problems> In order to solve the above-mentioned problems, the present invention uses magnetic interaction between an electromagnet and a permanent magnet to excite a diaphragm that is opposed to the magnetic pole of the electromagnet with an air gap interposed therebetween. In the electromagnetic acoustic transducer,
A flange member is inserted into the tip of the magnetic pole, and an insulating substrate having a pin terminal is integrally surface-bonded with the back surface of the yoke on which the magnetic pole is erected. A coil terminal of a coil constituting the electromagnet is connected and fixed to the pin terminal.

<Example> Fig. 3 is a front sectional view of the electromagnetic acoustic transducer according to the present invention, Fig. 4 is an exploded perspective view of the main parts, and Fig. 5 is an exploded perspective view of the main parts.
The figure is a perspective view of the main parts in an assembled state. In the figures, the same reference numerals as in FIGS. 1 and 2 indicate the same components. In this embodiment, a collar member 20 made of resin or the like is inserted into the tip of the magnetic pole 5, and a pair of pin terminals 3 and 4 are attached to the back surface of the yoke 6, which is opposite to the surface on which the magnetic pole 5 is erected. The implanted insulating substrates 13 are joined together in surface contact. The insulating substrate 13 may be configured as a printed circuit board.

For integral surface bonding of the yoke 6 and the insulating substrate 13, as shown in FIG. It is appropriate to have a structure in which the joint surfaces are bonded and fixed together with an adhesive or the like, while positioning is performed by fitting with the concave and convex portion 15. This results in an assembly similar to a conventional bobbin. Therefore, using this assembly as a bobbin, as shown in FIG.
Wrap it around.

As described above, according to the present invention, by integrally surface-bonding the insulating substrate 13 having the pin terminals 3 and 4 to the back surface of the yoke 6, an assembly having the same function as a conventional bobbin can be obtained. Therefore, it becomes possible to perform automatic winding by reusing the winding technology for other general coils, such as transformers.
Further, since a collar member 20 is inserted into the tip of the magnetic pole 5, the collar member 20 prevents the coil 2 from falling off.
It is possible to securely wind the winding while preventing the winding from collapsing. Moreover, since the collar member 20 is a separate member from the magnetic pole 5 and has a structure to be inserted into the magnetic pole 5, manufacturing of the magnetic pole 5 and the yoke 6 is easy. When the collar member 20 is made of synthetic resin as shown in the embodiment, it can be reliably fixed to the tip of the magnetic pole 5 due to its own elasticity.

Coil 2 wound around magnetic pole 5 as described above
As shown in FIG.
And insulating substrate 1 corresponding to these notches 16 and 17
Through the notches 18 and 19 opened on the periphery of 3,
It is guided from the upper surface side of the yoke 6 to the lower surface side of the insulating substrate 13, tied around the pin terminals 3 and 4, and fixed by soldering.

As described above, in the electromagnetic acoustic transducer according to the present invention, since the insulating substrate 13 on which the pin terminals 3 and 4 are inserted is integrally joined to the yoke 6, the coils are connected to the pin terminals 3 and 4 in advance. 2 coil terminals 21, 2
It is possible to assemble the two together. Therefore, disconnection accidents of the coil terminals 21 and 22 can be prevented. It also has the advantage of being able to be mounted on a printed circuit board by means such as solder dips.

Furthermore, since no bobbin is required, the occupancy of the coil 2 is high and the characteristics are improved, the heat dissipation of the heat generated by the coil 2 is good, the allowable current capacity of the coil 2 is increased, and the electromagnetic type is small and has a large output. Advantages such as being able to obtain an acoustic transducer, having a small number of parts, being compact, and being suitable as a sound reporting component in small devices such as wristwatches are also obtained.

<Effects of the invention> As described above, the present invention involves inserting a flange member into the tip of a magnetic pole, and integrally surface-bonding an insulating substrate having a pin terminal to the back of a yoke on which the magnetic pole is erected. Since the coil terminal of the coil that is directly wound around the magnetic pole and forms the electromagnet together with the magnetic pole is connected and fixed to the pin terminal, the winding process of the coil and the mounting work on the printed circuit board are easy, and the coil terminal An electromagnetic acoustic transducer that can reliably prevent disconnection accidents, has a high coil occupancy rate, provides good characteristics, has good heat dissipation against coil heat generation, has a large coil allowable current value, and is small and has a large output. It is easy to obtain, has a small number of parts, and is small.
It is possible to provide an electromagnetic acoustic transducer suitable as a sound reporting component in small devices such as wristwatches.

In addition, since a flange member is inserted into the tip of the magnetic pole, the flange member can prevent the coil from falling off or collapsing, and does not complicate the shape of the magnetic pole or make manufacturing difficult. Effects such as being able to prevent the coil from falling off and from collapsing can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional example of an electromagnetic acoustic transducer, FIG. 2 is a sectional view of another conventional example, and FIG. 3 is a front sectional view of an electromagnetic acoustic transducer according to the present invention. Figure 4 is an exploded perspective view of the main parts.
FIG. 5 is a perspective view of the main parts in an assembled state. 2... Coil, 3, 4... Pin terminal, 5... Magnetic pole, 6
...Yoke, 7. Permanent magnet, 8. Vibration plate, 13. Insulating substrate, 14. Recessed portion, 15. Convex portion, 20. Flange member.

Claims (1)

[Claims for Utility Model Registration] (1) In an electromagnetic acoustic transducer that excites a diaphragm that faces the magnetic pole of the electromagnet with an air gap interposed therebetween through magnetic interaction between an electromagnet and a permanent magnet. , a flange member is inserted into the tip of the magnetic pole, an insulating substrate having a pin terminal is integrally joined face-to-face with the back surface of the yoke on which the magnetic pole is erected, and is directly wound around the magnetic pole to form the magnetic pole. An electromagnetic acoustic transducer characterized in that a coil terminal of a coil constituting the electromagnet is connected and fixed to the pin terminal. (2) The electromagnetic acoustic transducer according to claim 1, wherein the yoke and the insulating substrate are positioned and fixed together by fitting the concave and convex portions of their joint surfaces.