JPS59216395A - Diaphragm for speaker - Google Patents

Abstract

PURPOSE:To attain high stiffness by using a woven cloth, where warps and woofs are arranged in parallel orthogonally to each other without knitting and threads arranged at about 45 deg. to their intersections are knitted, in a diaphragm for speaker using the woven clocth as a base material. CONSTITUTION:Plural woofs 1a are arranged in parallel at intervals of a proper length to constitute a woof group 11, and a warp group 21 consisting of plural warps 1b, 1b- is put on individual woofs 1a, 1a- orthogonally to them. Polyester fibrous threads 1c are arranged at about 45 deg. to warps 1b and woofs 1a and are knitted in parts, where warps 1b and woofs 1a are orthogonal to each other, in the expansion direction of fibrous threads 1c, and thus the warps and woofs are provided with a shape holding property as a woven cloth. Since the warps and woofs causing the stiffness of the diaphragm are woven without bending, the diaphragm with high stiffness is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in speaker diaphragms, particularly soft dome diaphragms.

Conventional soft dome diaphragms are made of woven fabric made of natural fibers such as silk or synthetic fibers such as polyester resin, phenol ceramic resin, etc.
Impregnated with excipient material such as epoxy resin and hot press molded to form a dome shape, then coated with damping material such as acrylic resin, or sheet made of woven fabric impregnated with excipient material and coated with damping material. It was molded by hot pressing.

Knitted plain weave cloth was often used.

However, as a result of the yarns of such a woven fabric being bent at the crossing portions, it acts as a comb line, making it impossible to sufficiently increase the rigidity of the formed diaphragm.

In addition, since the warp and cotton threads are knitted in an intersecting manner, thread deviation at the intersecting portion is small, making it difficult to press-form a diaphragm with a large curvature without causing deformation distortion. The same goes for twill weave and satin weave.

Therefore, this invention attempts to provide a soft dome diaphragm with high rigidity and large curvature by using a woven fabric with a special weaving method as the diaphragm base material. A woven fabric is used in which the warp and weft yarns are arranged orthogonally in parallel without being knitted, and the intersections of the warp and weft yarns are arranged in an approximately 45° direction.The following examples will be described in more detail.

In FIG. 1, 1a and 11) are yarns each made by twisting 20 phase fibers, 16 is a weft, and lb is a warp.

A plurality of weft yarns 1a are arranged in parallel at appropriate intervals to form a weft group 11, and each weft yarn 1a, 1a, . . .
・Multiple warps 1b, l are in contact with and perpendicular to the upper surface.
The warp groups 21 consisting of b, . . . are overlapped.

In this state, the warp threads 1b and the weft threads 1a are only in contact with each other and do not have shape retention properties as a woven fabric.

]C is a binding thread made by twisting polyester J fibers (10/
1m~15rl,,,'), the poly:r-s9
The polyester fiber yarns 1a are arranged at an angle of about 45° with respect to the warp 1b and the weft 1a, and
Along the elongation direction of c, the polyester fiber yarn IC is knitted together at the part where the warp threads 11 and the threads intersect at right angles, giving it shape 1 retention as a woven fabric.

The number of implants obtained in this way was 115 / 1nch.
A woven silk fabric of 0,59/100 crA is immersed in a 30 wt% phenol resin solution as a filler, pulled up, and dried at 105°C for about 10 minutes.

Next, a 60 wt % acrylic resin solution was coated as a damping material using a knife coater, and the material was dried at about 105° C. for 10 minutes to obtain a resin-coated cloth of 1.2 f/7100 cal.

This coating was press-molded for about 30 seconds in a heated mold at 180°C to 190°C, with a diameter of 25 + I + m1 and a total height of 7.5.
A dome-shaped diaphragm for the throat (diaphragm A) was obtained.

On the other hand, as a comparative material, a dome-shaped diaphragm (diaphragm B) having the same shape as rqtms-s was obtained by applying the same treatment to the above-described plain weave/li fabric made of only the silk thread.

As is clear from the above table of the test piece obtained by press-molding the dome-shaped diaphragms A and B, one portion of the flat outer periphery of the dome was cut out, the diaphragm according to the present invention and the diaphragm based on a conventional plain-woven fabric were compared. When compared, the internal loss is slightly (approximately 1
Although the Young's modulus decreased by about 18%, it was possible to increase the Young's modulus by about 18%.

This is thought to be due to the increased rigidity of the diaphragm of the present invention because the diaphragm serving as the substrate maintains its linear shape without bending.

Next, a speaker incorporating the diaphragms A and B.

The frequency characteristics of Kerr are shown in Figure 2.

As is clear from the figure, the frequency characteristic a of the speaker equipped with the diaphragm A of the present invention is 2.000) when compared with the frequency characteristic of the conventional speaker equipped with the diaphragm A.
The so-called mid-range valley between 1 z and 3000 Hz was reduced, and the reproduction high-frequency limit frequency fH was further increased, making it possible to expand the reproduction bandwidth.

As explained above, the present invention provides a speaker moving plate whose basic materials are at least a woven fabric made of natural or synthetic fibers and a filler, in which a plurality of woven fabrics are arranged in parallel at appropriate intervals. Warp threads 2"f 21 consisting of warp threads 1b, lb, . . . and weft threads 1a11a, superimposed perpendicularly thereto and arranged parallel to each other at appropriate intervals.
... a weft group 11 consisting of the warp 1b and the weft 1a
The weft 1a and the warp 1 are arranged at an angle of 45°.
It is characterized by the binding yarn 1c knitting together the portions where the diaphragm 1c and Since it does not impair Young's modulus, it is possible to provide a diaphragm with higher rigidity, and since the part where the warp and weft intersect is relatively loose, it can be pressed. We have described an example in which polyester fiber is used as the binding thread 1c, but the same effect can be obtained with other fibers, and the binding thread is not limited to being threaded in an X-shape as shown in the figure. Either one is fine.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a degenerate structure used in the diaphragm of the present invention;
The figure is a frequency characteristic diagram of a speaker equipped with the diaphragm of the present invention and a conventional diaphragm. 21 is a warp group, 11 is a weft group, 1b is a warp, 1a is a weft, ]c is a binding thread.

Claims (1)

[Claims] In a speaker diaphragm having at least a woven fabric as a base, the woven fabric forms an angle of approximately 45° with respect to a warp group (21) 11) consisting of a plurality of warps arranged in parallel at appropriate intervals and the warp and weft. The warp threads (lb
) and a weft (1a) are interwoven at right angles to each other.