JPH0116156Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is an electromagnetic device that excites a diaphragm facing the magnetic pole of the electromagnet with an air gap interposed therebetween by magnetic interaction between an electromagnet and a permanent magnet. The present invention relates to type acoustic transducers. 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 around 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 plastic molded 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. Note that 91 is a sound emitting 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 the same components.

Problems with the Prior Art Among the conventional electromagnetic acoustic transducers described above, the bobbin type shown in FIG. Since the winding structure is similar to that of
It is easy to wind the coil 2, and the bobbin 1
Since the pin terminals 3 and 4 are implanted in the coil terminals 21 and 2 of the coil 2,
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.

Purpose of the present invention Therefore, the present invention eliminates the drawbacks of the above-mentioned two conventional methods and extracts only the advantages, making it easy to wind the coil and mounting it on a printed circuit board, and prevent disconnection of the coil terminal. In addition, the coil occupancy rate is high, good characteristics are obtained, the heat dissipation property against the heat generated by the coil is good, the allowable current value of the coil is large, and an electromagnetic acoustic transducer that is small and has a large output can be obtained. It is an object of the present invention to provide an electromagnetic acoustic transducer that is easy to use, has a small number of parts, is small, and is suitable as a sound reporting component in small devices such as wristwatches.

Structure of the present invention In order to achieve the above object, the present invention is an electromagnetic type that excites a diaphragm facing the magnetic pole of the electromagnet with an air gap interposed therebetween by magnetic interaction between an electromagnet and a permanent magnet. In the acoustic transducer,
A flange member is inserted into the tip of the magnetic pole, a hole is provided in the yoke on which the magnetic pole is erected, and the insulated end of a pin terminal having an insulated end is inserted into the hole, and the insulated end of the pin terminal is inserted directly into the magnetic pole. A coil terminal of a coil that is wound and forms the electromagnet together with the magnetic pole is connected and fixed to the pin terminal.

Embodiment FIG. 3 is a front sectional view of an electromagnetic acoustic transducer according to the present invention, FIG. 4 is an exploded perspective view of the main parts, and FIG.
This figure and FIG. 6 are perspective views 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 flange member 19 made of synthetic resin is inserted into the tip of the magnetic pole 5 constituting the electromagnet, and a pair of holes 13 and 14 are formed through the yoke 6 in the thickness direction on which the magnetic pole 5 is erected. (see FIG. 4), and insulating ends 15, 1 are provided in the holes 13 and 14.
Said insulated ends 1 of pin terminals 3 and 4 having 6
5 and 16 are respectively inserted and attached by means such as press fitting. As a method for forming the insulating end portions 15 and 16 for the pin terminals 3 and 4, for example, as shown in FIG.
Possible methods include press-fitting the pin terminal 3 or 4 into the pin-shaped conductor 3 or 16, or forming an insulating resin 15 or 16 on one end of the pin-shaped conductor 3 or 4 by insert molding, as shown in FIG. .

Here, by inserting the insulated ends 15 and 16 of the pin terminals 3 and 4 into the holes 13 and 14 provided in the yoke 6, an assembly similar to a conventional bobbin can be obtained, so other general coils For example, it becomes possible to repurpose the winding technology of transformers and perform automatic winding. Therefore, the winding work of the coil 2 becomes very easy. Since the collar member 19 is inserted into the tip of the magnetic pole 5, when the coil 2 is wound around the magnetic pole 5 using an automatic winding device or the like, the coil 2 can be securely wound while preventing it from falling off or unwinding. Can be wrapped.
Moreover, since the flange member 19 is a separate component from the magnetic pole 5, a structure can be provided to prevent the coil 2 from falling off and from collapsing without complicating the shape of the magnetic pole 5. When the collar member 19 is made of synthetic resin as shown in the embodiment, the collar member 19 can be reliably inserted into the magnetic pole 5 due to its elasticity.

As shown in FIGS. 5 and 6, with respect to the magnetic pole 5 erected on one surface of the yoke 6,
The coil 2 is directly wound without using a bobbin, and the coil terminals 21 and 22 of the coil 2 are
It is guided from the upper surface side of the yoke 6 to the lower surface side through the notches 17 and 18 opened at the peripheral edge of the yoke 6, and is tied to the pin terminals 3 and 4 and fixed by soldering.

As mentioned above, the electromagnetic acoustic transducer according to the present invention has the pin terminals 3 and 4 inserted into the yoke 6,
Since it is possible to assemble the coil terminals 21 and 22 of the coil 2 by wrapping them around the pin terminals 3 and 4 in advance, 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 present invention As described above, the present invention provides an electromagnetic acoustic system that uses magnetic interaction between an electromagnet and a permanent magnet to excite a diaphragm that faces the magnetic pole of the electromagnet with an air gap in between. In the converter, a collar member is inserted into the tip of the magnetic pole, a hole is provided in the yoke in which the magnetic pole is erected, and the insulated end of a pin terminal having an insulated end is inserted into the hole, 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 disadvantages of the two conventional methods, namely, the bobbin method and the bobbinless method, can be overcome. Extracting only the advantages, it is easy to wind the coil and mount it on the printed circuit board.
It is an electromagnetic acoustic type that can reliably prevent disconnection accidents at the coil terminal, 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 high output. It is possible to provide an electromagnetic acoustic transducer that is easy to obtain, has a small number of parts, is compact, and is suitable as a sound reporting component in small devices such as wristwatches.

In addition, since the collar member is inserted into the tip of the magnetic pole, when winding the coil around the magnetic pole using an automatic winding device, etc., the coil does not fall off or collapse without complicating the shape of the magnetic pole. It is possible to provide a highly reliable electromagnetic acoustic transducer that can be wound reliably while preventing this.

[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.
5 and 6 are perspective views of the main parts in an assembled state, FIG. 7 is a diagram showing a method of forming an insulating end, and FIG. 8 is a diagram showing a method of forming an insulating end in another example. It is. 1...Case, 2...Coil, 3, 4...Pin terminal,
5... Magnetic pole, 6... Yoke, 7... Permanent magnet, 8... Vibration plate, 13, 14... Hole, 15, 16... Insulating end.

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 collar member is inserted into the tip of the magnetic pole, a hole is provided in the yoke on which the magnetic pole is erected, the insulated end of the pin terminal having an insulated end is inserted into the hole, and the insulated end of the pin terminal is inserted into the hole; An electromagnetic acoustic transducer characterized in that a coil terminal of a coil that is directly wound and forms the electromagnet together with the magnetic pole is connected and fixed to the pin terminal. (2) The electromagnetic acoustic transducer according to claim 1, wherein the insulated end of the pin terminal is formed by press-fitting an insulator into one end of a pin-shaped conductor. . (3) The electromagnetic acoustic transducer according to claim 1, wherein the insulated end of the pin terminal is formed by insert molding an insulating resin into one end of a pin-shaped conductor. vessel.