JPS5813674Y2 - speaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a speaker, and particularly to improvements in members constituting a magnetic circuit.

The magnetic circuit of a conventional speaker uses a magnetic material such as soft iron as a pole piece or plate near the voice coil.

Then, an audio current flows through the voice coil, and this current generates alternating magnetic flux, which is distorted by the nonlinear magnetization characteristics of the pole pieces and plates, resulting in sound pressure distortion.

To remove this distortion, it is known that if a magnetic material with low hysteresis loss is attached to the pole piece, plate, or both, the linearity of the minor loop will be made into a linear system and the distortion will be reduced. .

FIG. 1 shows a conventional magnetic circuit with low distortion measures, in which magnetic members 4 and 5, such as Ni--Fe alloy, with low hysteresis loss, are bonded to a plate 1 and a pole piece 3.

Because of their magnetic properties, the Ni-Fb gold alloy magnetic members 4 and 5 are molded into a ring shape, and their magnetic properties are deteriorated by mechanical stress applied during the manufacturing process such as surface polishing. It involves a lot of inefficient work.

Also, when adhering these Ni-Fe alloy magnetic members 4 and 5 to the plate and pole piece 3, large shocks are prohibited, and the work must be done with care, resulting in an efficient work.

The present invention has been devised to eliminate the above-mentioned drawbacks, and is intended to provide a device with stable performance at a low cost.

The illustrated embodiment will be explained below.

Figures 2 to 4 each show an embodiment of the present invention (・
Ru.

In FIG. 2, only the pole piece 6 is made of powder metallurgy, and in FIG. 3, only the plate 1 is made of powder metallurgy.

In FIG. 4, both the pole piece 6 and the plate 7 are made of powder metallurgy.

The pole piece 6 and the plate 7 are made of iron (Fe) as a raw material.
) Powder is put into each mold, compacted and sintered.

Here, in the conventional magnetic circuit shown in FIG.
The corresponding parts of the magnetic members 4 and 5 made of Fe alloy are mixed with raw materials at the same ratio of nickel powder and iron powder as this member, and the other parts are prepared using only Fe powder using a powder metallurgy manufacturing method. Manufacture L・ru.

As described above, the present invention uses the powder metallurgy manufacturing method to bond the magnetic members 4, 5, the plate 1, and the pole piece 3, thereby saving the labor and effort.

Further, the cost amplifier element due to the complicated shape of the pole piece 6 can be removed, and a speaker with stable performance can be provided at low cost.

[Brief explanation of the drawing]

FIG. 1 is a conventional sectional view, and FIGS. 2 to 4 are sectional views showing embodiments of the present invention. In the figure, 1 and 7 are plates, 2 is a magnet, and 3
, 6 are pole pieces, and 4 and 5 are magnetic members. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of utility model registration request] A speaker in which at least one of a pole piece and a plate constituting a magnetic circuit is manufactured by a powder metallurgy manufacturing method, and only the material near the voice coil is made of a Ni-Fe alloy, and the remaining part is made of iron.