JP2002271891A - Voice coil bobbin for speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a voice coil bobbin 1 for a speaker, which can prevent fire flame propagation of a reinforcement paper sheet 3 wound on the voice coil bobbin 1, a diaphragm and a damper when an excess current is supplied to a voice coil 2. SOLUTION: A perforated line 1a is formed in a circumferential direction to the voice coil bobbin 1 so as to separate a part of the voice coil bobbin 1 on which the voice coil 2 is wound from a part 3 of the voice coil bobbin 1 on which the damper and the diaphragm are fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voice coil bobbin of a speaker, and more particularly to a voice coil bobbin of a speaker capable of preventing a dam bar and a diaphragm from spreading when a large current is supplied to the voice coil.

[0002]

2. Description of the Related Art FIG. 3 shows an example of a voice coil bobbin of a conventional speaker, and FIG. 2 shows a speaker using the voice coil bobbin. A voice coil 5 is wound around a lower portion of the voice coil bobbin 4 shown in FIGS. 2 and 3, and an upper portion of the voice coil bobbin 4 is covered with a reinforcing paper 6.

[0003] The reinforcing paper 6 is bonded to the inner periphery of the damper 12 and the diaphragm 7, and the outer periphery of the damper 12 and the diaphragm 7 is supported by the frame 8. The voice coil 5 thus supported by the frame 8 is arranged in a magnetic gap of a magnetic circuit composed of the top plate 9, the magnet 10 and the yoke 11 also supported by the frame 8. When a voice signal current is supplied to the voice coil 5, the voice coil 5 causes the diaphragm 7 to vibrate by electromagnetic action to emit sound.

[0004]

In the above-mentioned conventional voice coil bobbin, when an excessive current is supplied to the voice coil, the voice coil bobbin may be ignited and the reinforcing paper may spread. As the reinforcing paper spreads, the diaphragm attached to it also spreads. Further, it is necessary to use a flame-retardant material so that the damper does not spread, and the manufacturing cost is high.

The speaker proposed in Japanese Utility Model Laid-Open Publication No. Sho 59-17693 has a through hole for passing an adhesive in the vicinity of a portion of a diaphragm to be bonded to a voice coil bobbin. In this loudspeaker, most of the diaphragm can be prevented from spreading if it burns down through the through hole, but the voice coil bobbin and the damper may spread.

In the loudspeaker proposed in Japanese Patent Laid-Open No. 11-4496, a radial groove is provided at an edge provided between the diaphragm and the frame. Since this groove does not extend in the circumferential direction, it is impossible to prevent the spread of fire at the edge. Also, it was naturally impossible to prevent the spread of the fire of the diaphragm and the damper located inside the edge.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object thereof is to provide a reinforcing paper, a diaphragm, and a diaphragm wound on a voice coil bobbin when an excessive current is supplied to a voice coil. An object of the present invention is to provide a voice coil bobbin of a speaker in which the spread of a damper is prevented.

Another object of the present invention is to provide a voice coil bobbin that does not require the use of a flame-retardant material for the damper and can reduce the manufacturing cost of the speaker.

[0009]

The voice coil bobbin of the speaker according to the present invention has a perforation formed in a circumferential direction so as to divide a portion where the voice coil is wound and a portion where the damper and the diaphragm are fixed. Things.

In the voice coil bobbin of the speaker according to the present invention, a reinforcing paper is wound around a portion where the damper and the diaphragm are fixed, and a portion between the portion where the reinforcing paper is wound and the voice coil is wound. A perforation is formed in the circumferential direction so as to divide the two portions.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A voice coil bobbin of a speaker according to an embodiment of the present invention will be described with reference to the drawings. Figure 1
1 is a side view showing a voice coil bobbin of a speaker according to an embodiment of the present invention. Voice coil bobbin 1 shown
Is wound with a voice coil 2 at the lower part, and reinforcing paper 3 is wound at the upper part.

A perforation 1 a is formed between the voice coil 2 of the voice coil bobbin 1 and the reinforcing paper 3. As in the conventional example, the outer periphery of the damper and the diaphragm adhered to the reinforcing paper 3 are supported by a frame, and the voice coil 2 is disposed in a magnetic gap of a magnetic circuit supported by the frame.

When an excessive current is supplied to the voice coil 2 of the thus constructed loudspeaker and the coiled portion of the voice coil 2 of the voice coil bobbin 1 is ignited, the lower portion of the voice coil bobbin 1 is located at the perforation 1a. Burnout of the reinforcing paper 3, damper, diaphragm and the like is prevented. Further, since the spread of fire is prevented in this way, it is not necessary to make the damper with an expensive flame-retardant material, and the manufacturing cost of the speaker can be reduced.

Although the embodiment is constructed as described above, the invention is not limited to this. For example, the damper and the diaphragm may be directly bonded to the voice coil bobbin without interposing a reinforcing paper.

The perforations may have a shape in which holes such as circles, squares, and triangles are arranged instead of a shape in which straight cuts are arranged, and a plurality of perforations may be used instead of one.

[0016]

According to the voice coil bobbin of the speaker according to the present invention, when an excessive current is supplied to the voice coil and the wound portion of the voice coil of the voice coil bobbin is ignited, the lower portion of the voice coil bobbin is cut at the perforation. Burnout of the reinforcing paper, damper, diaphragm and the like due to burnout is prevented.

Further, since the spread of fire is prevented in this way, it is not necessary to make the damper with an expensive flame-retardant material, and the manufacturing cost of the speaker can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view showing a voice coil bobbin of a speaker according to an embodiment of the present invention.

FIG. 2 is a side view showing a part of a speaker using a conventional voice coil bobbin as a partial cross section.

FIG. 3 is a side view showing the voice coil bobbin.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Voice coil bobbin, 1a Perforation 2 Voice coil 3 Reinforcement paper 4 Voice coil bobbin 5 Voice coil 6 Reinforcement paper 7 Diaphragm 8 Frame 9 Top plate 10 Magnet 11 Yoke 12 Damper

Claims (2)

[Claims] 1. A voice coil bobbin for a speaker, wherein a perforation is formed in a circumferential direction so as to divide a portion where a voice coil is wound and a portion where a damper and a diaphragm are fixed. 2. A reinforcing paper is wound around a portion where the damper and the diaphragm are fixed, and the two portions are divided between a portion where the reinforcing paper is wound and a portion where the voice coil is wound. A voice coil bobbin for a speaker, wherein perforations are formed in a circumferential direction.