JPS6219039Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an acoustic transducer such as a microphone or a speaker, and in particular, is capable of reliably fixing a magnetic circuit and easily obtaining a desired acoustic circuit.

Conventionally, in acoustic transducers such as microphones, the magnetic circuit has been assembled and fixed by caulking or filling with resin.

FIG. 1 shows a conventional microphone in which a magnetic circuit is assembled and fixed by caulking.
In FIG. 1, 1 indicates a yoke, and this yoke 1, a center pole 2, and a magnet 3 constitute a magnetic circuit having a rectangular cross section. In this case, a guide ring 4 is placed between the lower surface of the plate portion 1a of the yoke 1 and the seat surface of the flange portion 2a of the center pole 2.
The center pole 2, the magnet 3, and the yoke 1 are joined together by the restoring force of the guide ring 4. In addition, the first
In the figure, 5 is a voice coil, and 6 is a diaphragm.

By the way, with such a configuration, it is impossible to engage the guide ring 4 across the yoke 1 with a pot-shaped magnetic circuit rather than a magnetic circuit with a rectangular cross section as shown in the example in FIG. In the first place, it was not possible to employ such a joining method.

Further, FIG. 2 shows another example of a conventional microphone. In this figure, parts corresponding to those in FIG. 1 are designated by the same reference numerals, and detailed explanations thereof will be omitted.

In the example shown in FIG. 2, the yoke 1, magnet 3, and center pole 2 are fixed using an adhesive, and the yoke 1 is further filled with resin 7. In this case, since the yoke 1, the magnet 3, and the center pole 2 are not configured to be crimped, the bond between the yoke 1 and the magnet 3 and the bond between the magnet 3 and the center pole 2 are insufficient. , there were inconveniences such as deterioration of sound quality.

The present invention has been devised in view of these points, and it is an object of the present invention to provide an acoustic transducer that can securely fix a magnetic circuit and also easily obtain a desired acoustic circuit.

Hereinafter, an embodiment in which the acoustic transducer of the present invention is applied to a microphone will be described with reference to FIG. In FIG. 3, parts corresponding to those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 3, the holes 1b and 1b are arranged coaxially on the yoke 1, the magnet 3, and the center pole 2, respectively.
3b and 2b are formed. Center pole 2 hole 2
A screw groove 2c is formed along the magnet 3 in b. Then, a hollow screw member 11 is inserted into this screw groove 2c.
Screw one end of the A nut 12 is screwed onto the other end of the hollow screw member 11. In this case, if the nut 12 is tightly screwed together, the center pole 2, magnet 3, and yoke 1 will be securely and firmly fixed.

Further, in this example, a ring 13 is provided extending from the lower surface of the plate portion 1a of the yoke 1 to the side wall surface of the center pole 2. This ring 13 reduces the size of a cavity 13a that communicates with the gap between the center pole 2 and the plate portion 1a. In this way, the plate portion 1a and the voice coil 5
The adverse effects of the viscous resistance between the center pole 2 and the voice coil 5 and the viscous resistance between the center pole 2 and the voice coil 5 on sound quality can be reduced.

In such a configuration, if the nut 12 is tightly screwed into the hollow screw member 11, the connection between the yoke 1 and the magnet 3 and the connection between the magnet 3 and the center pole 2 can be ensured. Therefore, the sound quality is improved.

In addition, there is a cavity around the diaphragm 6 (indicated by A in Fig. 3).
are the hole 2b of the center pole 2 and the hollow screw member 1
1 to the outside of the yoke 1 (to the grip). The hole 2b of the center pole 2 and the hollow screw member 11 form a desired acoustic circuit.

As described above, according to the acoustic transducer of the present invention,
Since the center pole 2 is attached to the yoke 1 by the hollow screw member 11, the magnetic circuit can be assembled and fixed easily and reliably. Furthermore, there is no problem with a pot-shaped magnetic circuit instead of a square-shaped magnetic circuit in cross section.

Further, since the hollow portion of the hollow screw member 11 is used as a part of the acoustic circuit, a desired acoustic circuit can be easily obtained.

Next, another embodiment of the acoustic transducer of the present invention will be described with reference to FIG. In addition, in FIG. 4, the same reference numerals are given to the parts corresponding to those in FIG. 1, and detailed explanation of each part is omitted.

In the example in FIG. 4, a plurality of hollow screw members 1
1 is used. Then, a ring 13 having a corresponding number of screw holes 13a is engaged with the flange portion 2a of the center pole 2. One end of the hollow screw member 11 is screwed into the screw hole 13a of the ring 13, and a nut 12 is screwed into the other end of the hollow screw member 11. In addition, in FIG. 4, 14 indicates a resistive paper.

It will be easy to understand that the example in FIG. 4 also provides the same effects as the example in FIG. 3. Also,
In this example, a ring 13 that engages with the flange portion 2a of the center pole 2 is attached to the yoke 1 with a hollow screw member 11. Therefore, there is no need to form holes or cut thread grooves in the center pole 2 or magnet 3. This is advantageous in processing the center pole 2 and magnet 3.

In the above embodiment, only a microphone was mentioned, but it will be easily understood that the acoustic transducer of the present invention can be applied to other acoustic transducers such as a speaker.

It goes without saying that the present invention is not limited to the above-mentioned embodiments, and may take various configurations without departing from the gist thereof.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are sectional views showing conventional examples, respectively;
FIG. 3 is a cross-sectional view showing one embodiment of the acoustic transducer of the present invention, and FIG. 4 is a cross-sectional view showing another example of the acoustic transducer of the present invention. 1 is a yoke, 2 is a center pole, 2c is a screw groove, 11 is a hollow screw member, and 12 is a nut.

Claims (1)

[Scope of utility model registration request] An acoustic transducer characterized in that a center pole is attached to a yoke by a screw member, and the screw member is hollow so that the screw member constitutes a part of an acoustic circuit.