JPH07162992A - Speaker diaphragm - Google Patents

Abstract

PURPOSE:To suppress the individual resonance over the edge part in the specific frequency and provide the flat sound pressure frequency characteristic. CONSTITUTION:In an edge, part 8, a connection part 8a, edge roll 8b, and outerperipheral part 8c are formed concentrically. The edge roll 8b and the outerperipheral part 8c are formed concentrically. The innerperipheral part is formed elliptically. Thus, the width of the connection part 8a of the edge, part 8 becomes uneven all over the outerperipheral edge and the rigidity of the outerperipheral edge of the diaphragm body becomes different in each part and the specific frequency due to the individual resonance of the edge part 8 can be made different in each part. In the specific frequency, the individual resonance which occurs all over the edge part 8 can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker diaphragm.

[0002]

2. Description of the Related Art Generally, an edge portion of a speaker diaphragm is required to have flexibility that does not hinder the amplitude movement of the speaker diaphragm and appropriate vibration damping. Therefore, the diaphragm body and the edge portion are separately molded as separate members, and the diaphragm body and the joint portion provided on the edge portion are adhesively joined to form a speaker diaphragm. The speaker diaphragm configured in this manner is generally called a free edge diaphragm and is used in many speakers.

Further, as the edge portion of the above-mentioned free-edge diaphragm, a urethane foam molded into a roll having a substantially semicircular cross section is often used.

[0004]

However, since the speaker diaphragm having the above-mentioned structure has a single edge portion and has substantially uniform physical properties, a speaker using this speaker diaphragm has a specific shape. At the frequency, the natural resonance occurs around the entire circumference of the edge part, and due to the natural resonance of the edge part, a remarkable peak or dip appears at the above specific frequency in the frequency characteristic of the speaker, making it difficult to obtain a flat sound pressure frequency characteristic. However, there was a problem that the sound quality had a habit of hearing.

It is an object of the present invention to provide a speaker diaphragm capable of suppressing the natural resonance over the entire circumference of the edge portion at a specific frequency and obtaining a flat sound pressure frequency characteristic.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a speaker vibration in which a diaphragm body portion and an edge portion are individually molded, and the diaphragm body portion and a joint portion provided on the edge portion are adhesively joined. In the plate, the width of the joint portion provided at the edge portion is formed to be non-uniform along the outer peripheral edge of the diaphragm body portion.

[0007]

Therefore, the rigidity of the outer peripheral end of the diaphragm body is different in each part, and the specific frequency caused by the natural resonance of the edge part can be made different in each part.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a vertical sectional view showing the structure of a general speaker, and FIG. 2 is a front view (a) and a side sectional view (b) showing an edge portion of a speaker diaphragm according to an embodiment of the present invention.
FIG. 3 is a frequency characteristic diagram of a speaker using the speaker diaphragm configured by the edge portion.

As shown in FIG. 1, the speaker according to the present embodiment comprises a magnetic circuit section 1 and a vibrating section 2, of which the magnetic circuit section 1 is a circular flat plate portion 3a and a flat plate portion 3a. A cylindrical center pole 3b provided in the center of the
And a ring-shaped magnet 4 fixed to the center pole 3b side of the flat plate portion 3a concentrically with the center pole 3b, and a ring-shaped upper portion concentric with the magnet 4 on the upper end surface of the magnet 4. It consists of a plate 6. The magnetic flux from the magnet 4 is guided to the voice coil 5, which will be described later, by using a gap formed between the magnet 4 and the upper plate 6 and the center pole 3b as a magnetic gap.

The vibrating section 2 has a vibrating plate body 9 in the shape of a cone, and a central portion of the vibrating plate body 9 at the top of the cone has a voice coil as a vibration source. The voice coil bobbin 5a of No. 5 is fixed by adhesion or the like. A flexible annular damper 11 is fixed to the voice coil 5 and the diaphragm body 9 by adhesion or the like, and the outer peripheral portion of the damper 11 has a conical shape fixed to the upper end surface of the upper plate 6. The frame 7 is elastically supported by adhesion or the like. On the other hand, an edge portion 8 is adhered to the outer periphery of the cone bottom portion of the diaphragm body portion 9 with a joint portion 8a, and the edge portion 8 is fixed to the edge support portion 7a of the frame 7 by adhesion or the like. That is, the frame 7 supports the diaphragm body 9 by the edge portion 8 and the damper 11. Further, a dust cap 10 for dustproof is provided on the voice coil 8 side of the diaphragm body 9.

The diaphragm body 9 and the diaphragm body 9
The edge portion 8 adhered to the outer periphery of the cone bottom portion with the joint portion 8a constitutes a free edge diaphragm.

Further, the edge portion 8 is, as shown in FIG. 2, a joint portion 8a used for adhering to the diaphragm body portion 9.
An edge roll 8b that appropriately damps the vibration of the diaphragm body portion 9 and an outer peripheral edge portion 8c that is used to bond the edge support portion 7a of the frame 7 are integrally formed of urethane foam. The edge roll 8b and the outer peripheral edge portion 8c are concentrically formed into a circular shape, and the inner periphery of the joint portion 8a is formed into an elliptical shape.

Therefore, the width of the joint portion 8a of the edge portion 8 becomes non-uniform along the outer peripheral edge of the diaphragm body 9, and the rigidity of the outer peripheral edge of the diaphragm body 9 is different in each part, and the edge portion 8 is formed. The specific frequency due to the natural resonance can be made different in each part, and the natural resonance generated at the specific frequency over the entire circumference of the edge portion 8 can be suppressed.

Therefore, the solid line A in FIG. 3 shows the frequency characteristic of the speaker having a diameter of 10 cm using the free edge diaphragm constructed by using the edge portion 8. The broken line B in FIG. 3 is formed by using the same material as that of the present embodiment and forming the inner circumference of the joining portion 8a of the edge portion 8 into a circular shape, and the other shape having the same shape as that of the present embodiment. The frequency characteristics of the comparative example are shown.

Here, it can be seen that the frequency characteristic of the comparative example shown by the broken line B in FIG. 3 has a peak due to the resonance of the edge portion 8 and a dip due to the reverse resonance at around 2 kHz. On the other hand, in the frequency characteristics of the present embodiment shown by the solid line A, such peaks and dips are not recognized.

That is, in the free-edge diaphragm constructed by using the edge portion 8 in which the inner circumference of the joint portion 8a is formed in an elliptical shape, the rigidity of the outer peripheral end of the diaphragm body portion 9 is made different at each part.
Since the specific frequency caused by the natural resonance of the edge portion 8 can be made different in each part, a flat sound pressure frequency characteristic can be obtained. Therefore, resonance between the diaphragm body 9 and the edge 8 is eliminated, and it is possible to suppress the occurrence of a significant peak or dip in the frequency characteristics of the speaker.

Therefore, the speaker using the speaker diaphragm constructed by using the edge portion 8 in which the inner periphery of the joint portion 8a is formed in an elliptical shape as described above has excellent frequency characteristics and excellent acoustic characteristics. Become.

In this embodiment, urethane foam was used as the material for molding the edge portion 8, but the material is not limited to this. For example, woven cloth or nonwoven cloth may be impregnated with thermosetting resin such as phenol resin. It may be dried by hot pressing. Further, although the shape of the diaphragm body 9 is cone-shaped, the shape is not limited to this, and a diaphragm body 9 of, for example, a dome shape or a flat plate shape may be used.

[0020]

As described above, according to the present invention, the width of the joint portion provided at the edge portion is formed to be non-uniform along the outer peripheral edge of the diaphragm body, and the non-uniform joint is formed. The rigidity of the outer peripheral edge of the diaphragm body differs at each part by forming the speaker diaphragm by adhesively bonding the outer edge of the diaphragm body to the outer peripheral edge of the diaphragm body, and the specific frequency caused by the natural resonance of the edge part Since each part can be made different, it is possible to suppress the natural resonance that occurs over the entire circumference of the edge part at a specific frequency, and the speaker using this speaker diaphragm suppresses the occurrence of remarkable peaks or dips in the frequency characteristics. And excellent acoustic characteristics with good frequency characteristics can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the structure of a general speaker.

FIG. 2 is a front view (a) and a side sectional view (b) showing an edge portion of a speaker diaphragm according to an embodiment of the present invention.

FIG. 3 is a frequency characteristic diagram of a speaker using a speaker diaphragm configured by the edge portion.

[Explanation of symbols]

 1 magnetic circuit part 2 vibrating part 3 support plate 4 magnet 5 voice coil 6 plate 7 frame 8 edge 8a joint part 8b edge roll 8c outer peripheral part 9 vibrating plate body part 10 dust cap 11 damper

Claims (1)

[Claims] 1. A speaker diaphragm in which a diaphragm body portion and an edge portion are separately molded, and the diaphragm body portion and a joint portion provided on the edge portion are adhesively joined to each other. A speaker diaphragm, wherein the width of the joined portion is formed to be non-uniform along the outer peripheral edge of the diaphragm body.