JPS6039998A - Speaker - Google Patents

Abstract

PURPOSE:To obtain a speaker with an excellent characteristic having an edge with a comparatively higher rigidity and less anisotropy by using an edge where a meshed knitting woven cloth is used as two surface members and a foamed rubber group material is sandwiched therebetween and bonded. CONSTITUTION:The edge 2 is a rolled edge formed by using the knitting woven cloth where polyester threads are meshed by knitting as two surface members 2a, 2b, the foamed urethane sheet is sandwiched therebetween as a core member 2c in the form of sandwich, and heating and bonding them. The Young's modulus of the said knitting woven cloth is larger than the Young's modulus of the foamed urethane sheet and the tensile Young's modulus is E(0 deg.)approx.=E(45 deg.)approx.=E(90 deg.) respectively at 0 deg., 45 deg. and 90 deg.. The speaker having an excellent characteristic with the edge having a comparatively higher rigidity and less anisotropy is obtained by using the edge 2 stated above.

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 configured as described above properly maintains the longitudinal vibration of the diaphragm (1) and prevents the lateral vibration (rolling) of the diaphragm (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 such a function, the conventional edge (2) has a half-P point [or waveform, etc.] as shown in Fig. Rolled edges are often used.

Conventionally, as shown in Fig. 2, the material for the edge (2) has often been a resin-impregnated woven cloth made of orthogonal cotton threads that has a certain degree of rigidity and is easy to move in the front-rear direction, and has good formability. Recently, although the rigidity is low, the internal loss is high, so the vibration plate (1) and the resonance of the edge (2) itself are used.
Foamed rubber-based materials, such as foamed urethane, which can easily damp the resonance of

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. Another disadvantage of edge materials such as foamed urethane is that their stiffness is extremely low, and the internal loss is not large enough to damp the split vibrations at low frequencies that occur due to the low rigidity, resulting in a deterioration of speaker characteristics. was there.

[Summary of the invention]

The present invention was made in order to eliminate the drawbacks of the above-mentioned conventional products, and by using mesh-like knitted fabric as two surface materials, sandwiching a foamed rubber material between them, and using the joined edges. The present invention provides a speaker with excellent characteristics that has relatively high rigidity and edges with little anisotropy.

[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. The cloth is coated with two surface materials (2a), (
2b), and in between, place the urethane foam sheet as the core material (2c
) is a rolled edge formed by sandwiching it in a sandwich shape and heat-bonding it. It is desirable that the Young's modulus of the knitted woven fabric is greater than the Young's modulus of foamed urethane sheets 1 to 1, and the tensile Young's modulus is 0°, 45°, and 90°.
It is desirable that EO-"E45"=E90'.

The Kerr displacement characteristics of the edge constructed as described above were measured, and as conventional examples, the edge molded from the foamed urethane used in Example 1 and the cotton fabric widely used since 6C impregnated with resin were molded. Figure 4 shows the results of a comparison with a rolled edge. Looking at the results in FIG. 4, it can be seen that the edges of the example have the best linearity, although the slopes are different because the stiffness of each edge is slightly different. This is because the edge of the example uses a mesh-like knitted fabric with less anisotropy and urethane foam, and because the nonlinearity of both is partially offset by the composite, it has further structural symmetry. This is thought to be due to the presence of

Next, the harmonic distortion characteristics in the low range when used in a full-band speaker with a diameter of 5 cm are shown in Figure 5, using the stiffness and shape of the edges in Example 1 and the conventional example. Figure 6 shows the sound pressure-frequency characteristics at . As shown in the results in Figure 5, the harmonic distortion of the speaker using the edge of the example is 5 to 10 d13 lower in both the 2nd and 3rd distortions compared to the conventional example, confirming that the linearity is good. It was done. In addition, the sound pressure-frequency characteristics in the high range shown in Figure 6 are phenomena that are understood from the results of holography], and the split resonance of the edge from kHz to 3kt+z is 1k+ when using the conventional foamed urethane edge.
In contrast to Iz, it was found that in the example, it increased to 3kllz. This shows that the edge of the example has elasticity comparable to that of a conventional cotton cloth impregnated with a grease remover. Furthermore, since the edge of the example has a relatively large internal loss, the sound pressure-frequency characteristic becomes flatter.

These effects are unique to the present invention, and the surface material (2
When the materials of a), (2b) and the core material (2c) are reversed, that is, when the surface materials (2a) and (2b) are foamed urethane, and the core material (2c) is a mesh-like knitted woven fabric, , "The effect is less than that of Example 1.

In addition, in Example 1, polyester yarn was used as the mesh-like knitted fabric, but this material could include cotton yarn,
If it is a flexible fiber such as silk thread, nylon, acrylic, or aramid, and has the required rigidity as an edge,
This embodiment has substantially the same effect as the second embodiment. Furthermore, although foamed urethane was used as the core material, other foamed rubber-based materials may be used.

In general, fibers with high rigidity have a high melting point, and it is difficult to mold and join them at the same time as foamed urethane. It is also possible to heat bond and mold with
Adhesion molding may be performed using Mel 1 or liquid adhesive. Adhesives can also be used in thermal bonding to increase adhesion.

〔Effect of the invention〕

As described above, according to the present invention, a mesh-like knitted woven fabric is used as the surface material and edges bonded to a foamed rubber material are used as the core material, so there is less anisotropy and excellent linearity. However, edges with good symmetry can be obtained, which 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 diagram showing Kerr displacement characteristics of the edge of the embodiment and the conventional example.
FIG. 5 is a low-frequency harmonic distortion characteristic diagram of speakers using the Edges of the embodiment and the conventional example, and FIG. 6 is a sound pressure-frequency characteristic diagram of speakers using the Edges of the embodiment and the conventional example. In each figure, the same reference numerals indicate the same or equivalent parts, 0) Ham11m4N, (2) Hayesshi, (2a), (2b)
HA surface Tm material, (2c) is core material, (3) is frame,
(4) is a spider. Agent Masuo Oiwa Figure 2 Figure 3 Figure 4

Claims (4)

[Claims] (1) In a speaker that holds the diaphragm in a predetermined position by joining the diaphragm and the frame through an edge, the edge uses a mesh-like knitted fabric as two surface materials, and between the surface materials A speaker characterized by being made by sandwiching and bonding foamed rubber materials. (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 gym material.
Speakers listed in section. (3) The tensile Young's modulus of the knitted fabric is 0°, 45°,
EO at 90°” “E, I! The speaker according to claim 1 or 2, characterized in that +°”Es/. (4) The speaker according to any one of claims 1 to 3, wherein the bonding is heat bonding or bonding with an adhesive.