JPS5942790Y2 - speaker - Google Patents

Description

[Detailed description of the invention] The present invention relates to a speaker in which the magnetic gap is filled with magnetic fluid to prevent the temperature rise of the voice coil and to achieve high input resistance. To provide a speaker that does not scatter into gaps.

1 and 2 show conventional speakers.

In Figures 1 and 2, 1 is a plate with a hole formed in the center, 2 is a cylindrical magnet fixed on plate 1, and 3 is a cylindrical center pole fixed to the end face of magnet 2. A phase equalizer 4 is fixed to the end face of the center pole 3.

A plurality of slits 5 are formed in this phase equalizer 4, and the end face is formed in an arc shape.

6 is a cylindrical yoke, and this yoke 6 is attached to the plate 1.
Fixed on top.

Note that this yoke 6 and plate 1 may be integrated.

Reference numeral 7 denotes an annular top plate fixed on the yoke 6, and an annular magnetic gap is formed between the inner peripheral surface of the top plate 7 and the outer peripheral surface of the center pole 3.

8 is a diaphragm, and an edge portion 9 of this diaphragm 8 is fixed to the top plate 7 by a fixing ring 10.

A cylindrical coil bobbin 11 is provided on the diaphragm 8, and a voice coil 12 is wound around the coil bobbin 11.

This voice coil 12 is arranged in the magnetic gap section.

13 is a magnetic fluid filled in the magnetic gap.

This magnetic fluid 13 is made of superparamagnetic fine particles (for example, fine particles of magnetite, ferrite, etc. with a particle size of several hundred angstroms or less) in water or an organic solvent (for example, a hydrocarbon solution, a hydrogen fluoride solution, an ester solution, a -21J solution). It has high thermal conductivity and is suspended in a colloidal solution.

Note that, before suspending the fine particles in water or an organic solvent, it is preferable to cheat the surface of the fine particles with a long chain molecule such as dovsylbenzene or oleic acid.

In the conventional speaker described above, when a signal is applied to the voice coil 12, the diaphragm 8 vibrates and a sound wave is generated. It is the radiation that is emitted.

Joule heat generated in the voice coil 12 is dissipated to the top plate 7 and center pole 3 via the magnetic fluid 13, reducing the temperature rise of the voice coil 12, making the speaker highly resistant to input and improving power linearity. It will be improved.

However, in the conventional speaker described above, the magnetic fluid 13 is scattered due to the vibration of the voice coil 12, and the period during which the heat dissipation effect is exerted is shortened, and the scattered magnetic fluid 13 is scattered between the diaphragm 8 and the phase equalizer 4. This has the disadvantage that the low-frequency range level of the sound pressure frequency response is significantly lowered.

The present invention eliminates the above-mentioned drawbacks of the conventional technology, and an embodiment of the present invention will be described below with reference to FIG. 3.

In FIG. 3, reference numeral 15 denotes an annular groove formed on the outer periphery of the phase equalizer 4. In FIG.

As in the above embodiment, when the annular groove 15 is formed in the phase equalizer 4, the vibration of the diaphragm 8 causes the magnetic fluid to
3 vibrates, this magnetic fluid 13 enters the groove 15, but it does not scatter into the gap between the diaphragm 8 and the phase equalizer 4, and the heat dissipation effect of the magnetic fluid 13 is exerted for a long period of time. At the same time, the low frequency range level does not decrease.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a conventional speaker, FIG. 2 is a half-sectional view of a main part of the same speaker, and FIG. 3 is a half-sectional view of a main part of a speaker according to an embodiment of the present invention. 1...Plate, 2...Magnet,
3... Center pole, 4... Phase equalizer, 5... Slit, 6... Yoke, 7... Top plate, 8 ...Diaphragm, 9...Edge part, 10...Fixing ring, 11...Coil bobbin, 12...
・Voice coil 13...Magnetic fluid, 14...
...Throat, 15... Concave groove.

Claims (1)

[Scope of utility model registration request] A cylindrical center pole, a top plate having a hole, a phase equalizer having a slit and fixed to the end of the center pole, and a diaphragm arranged with a slit interposed in relation to the phase equalizer. a coil bobbin provided on the diaphragm; a voice coil wound around the coil bobbin and disposed in a magnetic gap formed between the outer peripheral surface of the center pole and the inner peripheral surface of the top plate; A speaker having a magnetic fluid filled in the magnetic gap, characterized in that an annular groove is formed on the outer periphery of the phase equalizer.