JPS6039997A - Speaker - Google Patents

Abstract

PURPOSE:To obtain a speaker having an edge with a comparatively higher rigidity and less anisotropy by using the edge where meshed knit woven cloth and foamed rubber group material are bonded. CONSTITUTION:The edge 2 is a rolled edge formed by heating and bonding the knit woven cloth 2a where polyester threads are meshed by knitting and the foamed urethane sheet 2b. The Young's modulus of the said knitting woen cloth 2a is larger than the Young's modulus of the foamed urethane sheet 2b and the tensile Young's modulus is respectively E(0 deg.)approx.=E(45 deg.)approx.=E(90 deg.) at 0 deg., 45 deg. and 90 deg.. The speaker with the excellent characteristic having the edge with the comparatively higher rigidity and less anisotropy is obtained by using the edge 2 like this.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to improvements in speakers, and more particularly to improvements in edges for speakers.

[Prior art]

Fig. 1 is a cross-sectional view of the speaker, and Fig. 2 is a plan view showing a part of the main part of the conventional Edge.
1) is a cone-shaped diaphragm designed to have a shape and outer diameter that provides the required reproduction band, and (2) is a diaphragm (1).
One end is glued to the outer peripheral edge of the frame (3), and the other end is attached to the frame (3).
the edge (4) which is glued to hold the diaphragm (1) in place; the voice coil (5) which drives the diaphragm (1);
A spider (7) is a magnetic circuit for driving the voice coil (5).

The edge (2) of the speaker drawn as above properly maintains the longitudinal vibration of the diaphragm (1), prevents the lateral vibration (low link) of the diaphragm (1), and (1) It also has the function of shielding the sound pressure from the back side from being transmitted to the front side. Furthermore, the edge (2) itself also contributes to the sound pressure as a part of the diaphragm (1).

In order to adapt to this function, the conventional Edge (2) has a semicircular or wave-shaped roll as shown in Figure 1, so that the amplitude of the diaphragm (1) in the longitudinal direction can be increased. Edges are often used.

Conventionally, the material for the edge (2) has a certain degree of rigidity and is easy to move in the front and back direction, as shown in Figure 2.
In addition, resin-impregnated cotton yarns spread at right angles and have good formability are often used.Recently, although the rigidity is low, the internal loss is high, so the resonance of the edge (2) itself and the diaphragm (1) are used.
) Foamed rubber-based materials such as foamed urethane, which can easily damp the resonance, have also come into use.

However, although the above-mentioned edges made of orthogonal woven fabrics such as cotton have high rigidity in the perpendicular warp and weft directions, the rigidity decreases in other directions, resulting in poor straightness and This had the disadvantage of causing non-axisymmetric vibrations at different frequencies, deteriorating the characteristics of the speaker. Furthermore, with edges such as urethane foam, the rigidity of the edge itself is extremely low.
The internal loss was not large enough to dampen the split vibrations at low frequencies that occur due to low rigidity, and as a result, the characteristics of the speaker deteriorated.

[Summary of the invention]

The present invention was made in order to eliminate the drawbacks of the above-mentioned conventional products, and by using an edge made by joining a mesh-like knitted fabric and a foamed rubber material, it has relatively high rigidity and anisotropic properties. This provides a speaker with excellent characteristics that has less edges.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is a plan view showing a part of the main part of the edge cut away in a speaker according to an embodiment of the present invention. This is a rolled edge formed by heat-bonding a cloth (2a) and a foamed urethane sheet (2b). It is desirable that the Young's modulus of the knitted woven fabric is larger than that of the foamed urethane fabric 1-, and the bow length IK l is 0°, 45°, and 90°.
It is desirable that 45°=E 9[1'.

The Kerr displacement characteristics of the edges constructed as described above were measured.As conventional examples, the edge molded from the foamed urethane used in the above example and the edge molded from the widely used cotton cloth impregnated with resin ( Figure 4 shows the results of comparison with roll edge. Looking at the results in FIG. 4, it can be seen that although the edges differ in slope because the stiffness of each edge is slightly different, the linearity of the edge in Example is the best. This is considered to be because the edge of the example employed a mesh-like knitted fabric with little anisotropy and urethane foam, and because the nonlinearity of the two was partially offset by the combination.

Next, Fig. 5 shows the harmonic distortion characteristics in the low range when the edge stiffness and shape of the above embodiment and the conventional example are the same and are used in a full-band speaker with a diameter of 6 cm.
Figure 6 shows the sound pressure-frequency characteristics in the high range. As shown in the results in Figure 5, the harmonic distortion of the speaker using the edge of the example is 2 to 5 dB lower in both 2nd and 3rd distortion than the conventional example, confirming that the linearity is good. Ta. In addition, the sound pressure-frequency characteristics in the high range shown in Fig. 6 show that the split resonance of the edge between 1 kllz and 4 kllz, a phenomenon that has been understood from the results of holography, is
1. When using conventional foamed urethane edge. kllz
On the other hand, it was found that in the example, the value increased to 2 kllz. Conventional (cotton cloth impregnated with M fat: 4kl)
Edge resonance is occurring in lz, but it is not as good as this,
The edge of the example has a relatively large internal loss, so the sound pressure -
The difference in frequency characteristics is not so remarkable.

In the second embodiment, polyester yarn was used as the mesh-like knitted fabric, but this material can be made of cotton yarn, silk yarn, nylon, acrylic, aramid, etc., and has the required rigidity as an edge. If it is a senki that has
Effects similar to those of the above embodiments Generally, fibers with high rigidity have a high melting point and are difficult to mold simultaneously with foamed urethane. In this case, the fibers are first impregnated with the required resin.
After molding, it may be molded by heating and bonding with foamed urethane, or it may be molded by adhesion to Hola 1-Mel 1 or via a liquid adhesive. Adhesives can also be used in heat bonding to increase adhesion.

〔Effect of the invention〕

As described above, since the present invention uses an edge made by joining a mesh-like knitted fabric and a foamed rubber material, an edge with less anisotropy and excellent linearity can be obtained, and as a result, This has the effect of improving the characteristics of the speaker.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a speaker, FIG. 2 is a plan view showing a part of the main part of a conventional edge cut away, and FIG. 3 is a cut away part of the main part of an edge according to an embodiment of the present invention. Fig. 4 is a Kerr displacement characteristic diagram of the edge of the implementation 491 and the conventional II+, and Figure 5 is a diagram of the low j or harmonic distortion characteristic of a speaker using the edge of the implementation 49u and the conventional example. , FIG. 6 is a sound pressure-frequency characteristic diagram of a speaker using an example and a conventional 4'A edge. In each figure, the same reference numerals indicate the same or (maoro to fitsro), (1) c diaphragm, (2) edge, (2a) u*
Me IJ Yasu 1 Te Mr. I [, (2b) is foamed urethane 1
To, (3)t:! , frame, (4) is a spider. Agent Masu Oiwa 1: Figure 2 Section 3 Figure 4 □f

Claims (4)

[Claims] (1) In a speaker that holds the diaphragm in a predetermined position by joining the diaphragm and the frame through edges, the edges are made by joining a mesh-like stockinated fabric and a foamed rubber-based material. A speaker with certain characteristics. (2) Claim 1, characterized in that the Young's modulus of the knitted woven fabric is greater than the Young's modulus of the foamed rubber material.
Speakers listed in section. (3) The tensile Young's modulus of the knitted fabric is Oo, 45°,
E o' −= E 4 at 90°! ,' = E so
"The speaker according to claim 1 or 2, characterized in that the speaker is ". (4) The speaker according to any one of claims 1 to 3, wherein the bonding is heat bonding or bonding with an adhesive.