JPS5855738Y2 - speaker - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a speaker that can reduce leakage magnetic flux from the magnetic circuit to the frame and reduce current distortion by improving the frame.

In general, a speaker was constructed as shown in FIG.

That is, a plate 2 having a center pole 1, a ring-shaped magnet 3, and a ring-shaped upper plate 4.
A frame 6 is coupled to a magnetic circuit 5 constituted by,
The peripheral edge of the diaphragm 8 is bonded to the peripheral edge of the frame 6 together with the gasket 7 using an adhesive or the like, and the voice coil 9 is bonded to the center of the diaphragm 8.
The middle part of the voice coil 9 is held by a damper 10, the lower part of the voice coil 9 is fitted into the magnetic gap 11 of the magnetic circuit 5, and a dust cap 12 is attached to the upper center surface of the diaphragm 8.

In a speaker with such a configuration, in order to reduce leakage magnetic flux from the magnetic circuit 5 to the frame 6 and to reduce current distortion, the frame 6 has conventionally been constructed of a non-magnetic material as shown in Fig. 2. Or, the center pole 1 was covered with a copper cap 13.

However, in such a configuration, the frame 6 is made of a non-magnetic material to reduce leakage magnetic flux, and the copper cap 13 is used to reduce current distortion, so there are many components.
In addition to requiring time and effort to assemble, it was also disadvantageous in terms of cost.

Moreover, the frame 6 is different from the magnetic circuit 5.
It is mounted by placing the bottom surface of the frame 6 on the frame 6 and mechanically joining it by welding, gluing, tightening, etc., but when installing it, it is necessary to position it with a jig or the like so that the center axis of the frame 6 coincides with the center axis of the magnetic circuit 5. This was a major obstacle to improving productivity.

The present invention eliminates the above-mentioned drawbacks of the prior art.

Hereinafter, an embodiment of the present invention will be explained with reference to FIG. 3 of the drawing.

That is, the entire frame 6 or at least its bottom part is made of μ magnetic material, and a cylindrical protrusion 14 that protrudes downward along the inner circumferential surface of the upper plate 4 is provided at the center of the bottom of the frame 6. At least the bottom portion of the frame 6 including the shaped protrusion 14 is plated with copper 15.

By setting frame 6 like this, frame 6
is positioned on the upper plate 4 of the magnetic circuit 5 by the cylindrical protrusion 14 and is connected to the upper plate 4 of the magnetic circuit 5 by means such as welding, gluing, tightening, etc., the magnetic circuit 5. The central axes of the frame 6 and the center axis of the frame 6 completely coincide with each other.

Moreover, since the whole or at least the bottom part of the frame 6 is made of a non-magnetic material, leakage magnetic flux from the magnetic circuit 5 to the frame 6 is also eliminated, and the cylindrical protrusion 14 coated with copper plating 15 is connected to the magnetic gap 11. Due to the presence of this copper plating 15, the voice coil 9
This means that current distortion can be prevented from occurring when a current is applied to the device and the device operates.

In the above embodiment, the frame 6 is plated with copper 15.
In the above description, a thin copper plate may be pasted or crimped, as long as the copper layer forms the magnetic gap 11.

As the speaker of the present invention is constructed as described above, it is possible to reduce leakage magnetic flux and current distortion by simply making improvements to the frame, and furthermore, the cylindrical protrusion of the frame can be used to position the frame relative to the magnetic circuit. This is advantageous in improving the productivity of speaker assembly, and as a result, it is possible to prevent the occurrence of abnormal noise due to voice coil gap rubbing, and it also improves quality, which is of great practical value. be.

[Brief explanation of the drawing]

FIG. 1 is a half-sectional view of a general speaker, FIG. 2 is a sectional view of a main part of a conventional speaker, and FIG. 3 is a sectional view of a main part of an embodiment of the speaker of the present invention. 5... Magnetic circuit, 6... Frame, 8
...Diaphragm, 9...Voice coil, 1
1... Magnetic gap, 14... Cylindrical protrusion, 15... Copper layer.

Claims (1)

[Scope of utility model registration request] A speaker in which a peripheral edge of a diaphragm is coupled to a peripheral edge of a frame coupled to a magnetic circuit, and a voice coil that fits into the magnetic gap of the magnetic circuit is coupled to the diaphragm, and at least the bottom of the frame is non-magnetic. What is claimed is: 1. A speaker made of a body material, provided with a cylindrical protrusion forming the outer periphery of a magnetic gap at the center of the bottom, and a copper layer formed on at least the surface of the bottom including the cylindrical protrusion.