JPS58131895A - Diaphragm for loudspeaker - Google Patents

Abstract

PURPOSE:To obtain a titled diaphragm which is light and excellent in humidity resistance and workability, and also to obtain a reproducing sound of high fidelity, by forming it by laminating a glass fiber formed like a mesh and a paper material. CONSTITUTION:On the surface of a paper material 1, for instance, plural glass fibers having a diameter of micron order are bundled and are formed like fibers, and also by bridge-coupling these fibers longitudinally and laterally, glass fibers formed like a mesh of 0.5-1.0 are made to adhere thermally. Also, to the glass fibers, for instance, thermosetting resin consisting of epoxy resin, etc. is applied, they are superposed on the paper material formed like a cone in advance, and both of them can be junctioned as one body by heating and pressing them. In this way, rigidity is raised suitably, divided vibration can be prevented almost completely, peak dip in high frequency range can be prevented, and a well- balanced tone quality can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a diaphragm for a speaker, and more particularly to a diaphragm for a speaker made of a laminate (1) of glass fiber and paper material formed in a mesh shape.

In general, the characteristics of the diaphragm used in high-fidelity speakers include that the material should have relatively high elasticity or rigidity, have an appropriate internal loss, and be lightweight. On the other hand, from the viewpoint of convenience and production process, it is required to have high moisture resistance and processability.

However, since paper material has appropriate internal loss and is lightweight (average density is 0-5 g/cc), diaphragms mainly composed of paper made from natural pulp have traditionally been used. It is widely used.

However, the above-mentioned paper materials are subjected to so-called beating treatment in the paper-making process, but depending on the conditions of this treatment,
Since the above-mentioned physical properties vary in various ways, it has not always been easy to ultimately make the acoustic characteristics of the diaphragm uniform. Furthermore, speakers with paper diaphragms tend to have noticeable peaks and dips in their frequency characteristics, so they have the disadvantage that it is difficult to obtain faithful reproduction sound.

(2) Furthermore, since paper materials generally have low elasticity, they have low rigidity, and it has been pointed out in the past that a troublesome phenomenon called split vibration occurs. In other words, with a speaker using a paper diaphragm, there is no problem with separate installation while it vibrates in the low range, but if the frequency is gradually increased and 400H
When the value exceeds 2, the amplitude decreases toward the outer periphery, reaching zero at the outermost periphery, and finally, from this point, vibrations of opposite phase move inward, which in turn causes the reproduced sound to become distorted. 17 The above-mentioned split vibrations are difficult to occur in high- and mid-range reproduction speakers with small cone diameters, and are very likely to occur in speakers with large diameters.It is possible to prevent such split vibrations from occurring. This has long been required in order to obtain faithful reproduction sound.

On the other hand, as a means to solve these problems, a speaker diaphragm of a type in which whisker-shaped metal fibers are mixed into paper material has been proposed, but if only one fiber is mixed in, , it is difficult for the fibers mentioned above to be distributed uniformly during paper making, etc. (3) Even if they are distributed uniformly, due to their nature, the fibers tend to be oriented in a certain direction, which makes it difficult to reproduce sound as a speaker. This had a distinct drawback in that it was likely to result in a loss of fidelity.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a diaphragm for a speaker that can eliminate the various drawbacks mentioned above.

Examples of the speaker diaphragm according to the present invention (hereinafter referred to as the product of the present invention) will be described below.

FIG. 1 is a partially exploded sectional view showing one embodiment of the present invention, showing a diaphragm of a cone speaker having a maximum outer diameter of about 250 mm. That is, as shown in the figure, glass fibers 2 having a mesh shape are thermally bonded to the surface (inner surface) of a paper material 1. This glass fiber is formed into a fibrous shape by bundling multiple glass fibers with diameters on the micron order, and by cross-linking these fibers vertically and horizontally, it is formed into a mesh shape of 0.5 to 1.0. It is formed. Then, the glass fibers are coated with a thermosetting resin such as epoxy resin, and then shaped into a cone shape (4).
The two are joined together by pressurizing and heating at a heating temperature of .

It was experimentally confirmed that the speaker diaphragm produced in this way has a moderately increased rigidity, and as a result, the above-mentioned split vibration can be almost completely prevented.

Furthermore, when the frequency characteristics of a speaker using the product of the present invention were measured, eight curves shown in FIG. 2 were obtained. Note that the A curve is the frequency characteristic of a speaker using a paper speaker diaphragm having the same shape and dimensions as the above speaker.

As can be seen in the figure, the speaker using the product of the present invention has a significantly reduced peak depth, especially in the high frequency range, compared to the speaker made of paper material.

FIG. 3 is a partially exploded sectional view showing another embodiment of the present invention. That is, it is a cone speaker with a maximum outer diameter of about 250 rrrmφ, and a glass fiber 2 having a mesh shape is thermally bonded to the back surface (outer surface) of a paper material 1 (5). The pressurization and heating of the glass fiber and paper material is the same as in the previous embodiment. FIG. 4 shows still another embodiment in which the glass fiber 2 is sandwiched between two sheets of paper 1.1 and laminated. The pressurization and heating in between is the same as in the previous example.

The frequency characteristics of a speaker using a laminated speaker diaphragm as shown in FIG. 3 or FIG. 4 are also very similar to the curve B in FIG. 2, and there is no peak/depth in the high frequency range.

Since the product of the present invention is constructed as described above, it has relatively high elasticity, that is, high rigidity, and is lightweight because it uses paper material. In addition, it is superior to a single paper material in terms of moisture resistance, and no particular problems have been found in processability (including releasability from a mold). In addition to being able to prevent so-called split vibrations, in terms of frequency characteristics, the ability to prevent peaks and dips in the high frequency range has a remarkable effect, so the sound quality of speakers using the product of the present invention can be improved by its powerful, soft sound quality. It provides a well-balanced sound quality that is rich in sound, brightness, and delicacy.

[Brief explanation of the drawing]

FIG. 1 is a partially fragmented sectional view showing one embodiment of the product of the present invention;
FIG. 2 is a diagram showing the frequency characteristics of the product of the present invention and a speaker using paper material, and FIGS. 3 and 4 are diagrams showing other embodiments of the present invention. 1...Paper material, 2...Glass fiber. Patent applicant: Tonegen Co., Ltd. Patent attorney Koji Onishi (7) Figure 1 Figure 3 Figure 4

Claims (4)

[Claims] (1) A diaphragm for a speaker, characterized in that it is formed by laminating paper material and glass fiber formed in a mesh shape. (2) The diaphragm for a speaker according to claim 1, wherein the glass fiber is laminated on the surface of a paper material. (3) The diaphragm for a speaker according to claim 1, wherein the glass fiber is laminated on the back side of a paper material. (4) The diaphragm for a speaker according to claim 1, wherein the glass fiber is laminated by sandwiching two sheets of paper together.