JP2000036995A - Speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speaker having a flat sound pressure frequency characteristic for an acoustic device or the like. SOLUTION: This speaker is configured with a dust cap 14a used for at least the speaker that is foamed in a bowl shape with a thin thickness in a metallic die, and the dust cap 14a made of a foamed rubber with a high mechanical internal loss is coupled with a part of a diaphragm in split vibration having large amplitude to provide damping to the split vibration of the diaphragm 12 to realize a smooth sound pressure frequency characteristic thereby enhancing the sound quality.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker used for various kinds of audio equipment.

[0002]

2. Description of the Related Art A conventional speaker will be described with reference to a side sectional view of FIG.

According to FIG. 1, reference numeral 1 denotes a bottom plate having a columnar pole piece 2;
The ring-shaped magnet 4 joined to the magnet 3 is a top plate that is joined to the magnet 3 and forms an annular magnetic gap 5 together with the pole piece 2. The above constitutes the magnetic circuit 6. Reference numeral 7 denotes a frame joined to the top plate 4, which fixes a vibration system component at an outer peripheral end and is fixed to a speaker cabinet (not shown). The vibration system components include a voice coil 8 composed of a voice coil bobbin 10 wound with a voice coil wire 9 that fits in the magnetic gap 5, and a damper 11 that suspends and supports the voice coil bobbin 10 so as to vibrate. A peripheral hole is joined to the voice coil bobbin 10, and an outer peripheral portion is
And an inverted conical diaphragm 12 fixed to the diaphragm. Reference numeral 14 denotes a paper dust cap whose periphery is fixed to the diaphragm 12 to prevent foreign matter from entering the magnetic gap 5 and to acoustically shield the front and rear of the diaphragm 12.

The operation of the loudspeaker having the above configuration will be described below. When a signal is externally applied to the voice coil wire 9, a driving force is generated by a driving current, the voice coil bobbin 10 moves in a piston, the diaphragm 12 vibrates, and a sound wave is emitted.

[0005]

However, since the above-mentioned speaker drives the center portion of the diaphragm 12 and fixes the edge 13 to the outer peripheral portion, the low-tone range vibrates the piston, but the mid-range sound. In the middle and high frequency range, the balance between the rigidity of the diaphragm 12 and the internal mechanical loss is deteriorated, and severe splitting vibrations are likely to occur. A peak dip occurs in the frequency characteristics of the reproduced sound pressure, and the sound pressure frequency characteristics Was caused.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a loudspeaker which is less likely to cause split resonance, has smooth frequency characteristics, and has excellent sound quality.

[0007]

According to the present invention, there is provided a speaker comprising at least a magnetic circuit, a frame connected to the magnetic circuit, and a diaphragm having an outer periphery connected to the frame via an edge. And a voice coil fitted in the magnetic gap of the magnetic circuit coupled to the inner periphery of the diaphragm, and a bowl-shaped thinner outer periphery in a mold coupled to the diaphragm so as to cover the voice coil. It is composed of a thick dust-molded dust cap, and a large-amplitude portion of the vibrating plate that is divided and vibrated is connected to a dust cap made of foamed rubber with large internal loss. To achieve smooth sound pressure frequency characteristics to improve sound quality.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A loudspeaker according to the present invention has at least a magnetic circuit, a frame coupled to the magnetic circuit, and a diaphragm having an outer periphery coupled to the frame via an edge. A voice coil fitted into the magnetic gap of the magnetic circuit coupled to the inner periphery of the diaphragm; and a thin wall-shaped bowl having a periphery covered with the diaphragm so as to cover the voice coil. It is composed of a dust cap that is foam-molded on the diaphragm, and a dust cap made of foamed rubber with large mechanical internal loss is connected to the place where the amplitude of the vibrating plate that splits and vibrates is large, to reduce the split vibration of the diaphragm. It is intended to improve sound quality by realizing smooth sound pressure frequency characteristics by braking.

An embodiment of a speaker according to the present invention will be described below with reference to FIGS. Note that the same parts as those in the prior art are denoted by the same reference numerals and description thereof will be omitted. In particular, the configuration of the entire speaker is almost the same as that of the related art, and only the characteristic portions will be described in the embodiments.

FIG. 1 is a side sectional view of a dust cap which is a main part of the speaker of the present invention, FIG. 2 is an enlarged sectional view of the same, and FIG. 3 is a sound pressure frequency characteristic diagram of the speaker.

The difference from the prior art is that the dust cap 14
a, which is formed of a foamed rubber which is thinly foamed in a mold instead of the conventional paper dust cap 14 (not shown). The foamed rubber contains styrene-butadiene as a main component and a foaming agent. And the like.

FIG. 3 shows the sound pressure frequency characteristic of the speaker. The frequency sound pressure characteristic a of the speaker of this embodiment using the foam rubber dust cap 14a is flatter than that of the conventional speaker b. It was confirmed that it could be obtained.

Since the dust cap 14a is made of foamed rubber, a cavity c is generated in the dust cap 14a as shown in FIG. 2, thereby increasing the mechanical internal loss as compared with the conventional one, and It is considered that the vibration of the split resonance is absorbed and a flat frequency sound pressure characteristic is obtained.

In the above embodiment, the foamed rubber is described as having styrene-butadiene as a main component. However, other materials capable of producing foamed rubber according to the characteristics of the speaker, for example, nitrile-butadiene rubber, ethylene-butadiene, A synthetic rubber such as a propylene-polymer or a known chloroprene rubber may be used.

[0015]

According to the present invention, a dust cap formed by foaming in a mold as described above is used to absorb the vibration of the split resonance of the diaphragm and to improve the sound quality of a flat frequency sound pressure characteristic. It can be provided.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a dust cap which is a main part of an embodiment of a speaker according to the present invention.

FIG. 2 is an enlarged cross-sectional view of a dust cap which is a main part of the same.

FIG. 3 is a graph showing the same sound pressure frequency characteristics.

FIG. 4 is a side sectional view of a conventional speaker.

[Explanation of symbols]

 Reference Signs List 5 magnetic gap 6 magnetic circuit 7 frame 8 voice coil 12 diaphragm 14a dust cap

Claims (1)

[Claims] At least a magnetic circuit, a frame coupled to the magnetic circuit, a diaphragm having an outer periphery coupled to the frame via an edge, and a magnetic circuit of the magnetic circuit coupled to an inner periphery of the diaphragm. A speaker comprising: a voice coil fitted in a gap; and a dust cap formed into a bowl-like thin-walled foam in a mold connected to the diaphragm so as to cover the voice coil.