JPH03201795A - Diaphragm for speaker - Google Patents

Abstract

PURPOSE:To control the frequency characteristic without changing the cross sectional shape or the thickness of a diaphragm by applying heat forming to part of resin impregnated woven cloth at a specific heat temperature in the case of the heat press forming and forming a low elastic part to the part of the diaphragm. CONSTITUTION:When a diaphragm 1 is subject to heat press forming, part of a resin impregnated woven cloth is heat-formed in a range of heat temperature of 120-150 deg.C to form a low elastic part 2 to part of the diaphragm. Thus, since the elastic modulus of high strength polyethylene fibers in the low elastic part formed to part of the diaphragm for speaker is reduced to a half the elastic modulus of the high strength polyethylene fibers in the other parts, the propagation speed is reduced in the part. Thus, the propagation of a high frequency signal is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a diaphragm for a speaker, and more particularly to a diaphragm for a speaker manufactured by thermoforming a resin-impregnated woven fabric.

[Prior Art] Conventionally, a woven fabric made of high-strength polyethylene fibers or a woven fabric made of this high-density polyethylene fiber and other organic or inorganic fibers is impregnated with a thermosetting resin, and after semi-drying, the resin-impregnated woven fabric is There is a speaker diaphragm made by thermo-pressing cloth into a predetermined diaphragm shape.

[Problem to be solved by the invention] With valve-based diaphragms, it is relatively easy to change the elastic modulus and density (internal loss) of a part of the diaphragm using paper-making technology, but For diaphragms and diaphragms manufactured by hot-pressing FRP materials such as those mentioned above, it is difficult to change the elastic modulus of one part of the diaphragm, and the elastic modulus is the same in all parts. By changing the cross-sectional shape and thickness of the diaphragm, the frequency characteristics of the diaphragm speaker unit used were controlled.

An object of the present invention is to provide a diaphragm for a speaker in which the modulus of elasticity can be partially changed without changing the cross-sectional shape or wall thickness of the diaphragm, thereby controlling the frequency characteristics of the speaker. .

[Means for Solving the Problems] In order to achieve the above object, the present invention uses high strength polyethylene fibers (density 0.98 or less, elastic modulus 108
00 kg/ll1m") is impregnated with a thermosetting resin, and after semi-drying, this resin-impregnated woven fabric is thermo-press molded to produce a speaker diaphragm, and a portion of the resin-impregnated woven fabric is A low elasticity part is formed in a part of the diaphragm by heating and forming the high-strength polyethylene fiber under temperature conditions such that the elastic modulus is 1/2 or less, that is, within the range of 120°C to 150°C. By providing portions with different elastic moduli and internal losses, the frequency characteristics of the speaker are controlled.

In this case, the low elasticity portion should be formed in a frequency dividing manner or in a ring shape to provide balance to the entire diaphragm.

[Function] When thermo-pressing a resin-impregnated woven fabric using a diaphragm molding mold that allows heating temperature to be partially controlled, a portion of the resin-impregnated woven fabric is within the range of 120°C to 150°C. Set it so that it looks like this and heat and press it. Alternatively, in the first step, uniform temperature molding is performed at a temperature of 130° C. or lower, and in the second step, a portion is hot-pressed using a mold to set the temperature within the range of 120° C. to 150° C.

In the resulting speaker diaphragm, the elastic modulus of the high-strength polyethylene fibers in the low-elasticity portion formed in a portion thereof is reduced to 1/2 of the elastic modulus of the high-strength polyethylene fibers in other portions. Therefore, since the propagation speed decreases in this part, it is possible to control the propagation of high frequencies in this part.

[Embodiment] An embodiment of the present invention will be described based on the drawings. Fig. 1 is a plan view of a cone-shaped diaphragm, Fig. 2 is a side view of the same, and Figs. 3 and 4 are views of a low elastic part. A plan view showing another example of the formation pattern, FIG. 5 shows an example of a dome-shaped diaphragm, and (A
) is a plan view, and (B) is a side view. FIG. 6 is a frequency characteristic comparison diagram comparing the frequency characteristics of a speaker using the diaphragm of FIG. 1 with the frequency characteristics of a speaker using a conventional diaphragm.

In the figure, 1 indicates the entire speaker diaphragm,
High strength polyethylene fiber (density 0.98 or less, elastic modulus 1
0800 Kg/m+a") or a woven fabric made of this high-density polyethylene fiber and other organic or inorganic fibers is impregnated with a thermosetting resin, and after drying, the resin-impregnated woven fabric is thermo-press molded. However, when the diaphragm 1 is thermoformed, a portion of the resin-impregnated woven fabric is thermoformed at a heating temperature of 120°C to 150°C, thereby creating a low elasticity region in a part of the diaphragm. 2 was formed.

Example 1 High strength polyethylene fiber (density 0.98 or less).

A woven fabric with an elastic modulus of 10,800 Kg/mm") is formed, and it is impregnated with a thermosetting resin such as an epoxy resin.
Dry until the resin loses its tackiness. This resin-impregnated woven fabric is heated and pressure-molded in a cone-shaped diaphragm molding mold, but this mold is one that can partially control the heating temperature, and the resin-impregnated woven fabric to be molded is The heating temperature of a portion, for example, a ring-shaped or concentric portion, was set within the range of 120°C to 150°C, and the other portions were molded at 120°C.

The resulting diaphragm 1 has a ring-shaped low elasticity section 2 as shown in FIGS. 1 and 2, and a concentric ring-shaped low elasticity section 2 as shown in FIG. The elastic modulus of the high-strength polyethylene fibers is 1/2 of the elastic modulus of the high-strength polyethylene fibers in other parts.

In addition, during the above-mentioned hot-press molding, uniform temperature molding is performed at a temperature of 130 ° C or less in the first step, and in the second step, a part of the mold is set to be within the range of 120 ° C to 150 ° C. It may also be hot-press molded.

Example 2 Organic fibers with a melting point of 150° C. or higher and the above high-strength polyethylene fibers (density 0.98 or lower, elastic modulus 1080
0 Kg/mm"), and the rest was the same as in Example 1.

The elastic modulus of the high-strength polyethylene fibers in the low-elasticity portion 2 of the resulting diaphragm 1 was 1/2 of the elastic modulus of the high-strength polyethylene fibers in other portions.

Example 3 As a woven fabric, an inorganic fiber with a glass point shift of 90°C or higher (carbon fiber in the example) and the above-mentioned high-strength polyethylene fiber (density 0.98 or lower, elastic modulus 10800 Kg/mm") were woven, or other fabrics were woven. The procedure was the same as in Example 1.

The diaphragm thus obtained had the same results as in Example 1.

The low elasticity part 2 to be formed may be formed in frequency-divided manner as shown in FIG. may be formed.

FIG. 6 shows the cone-shaped diaphragm l obtained in Example 1.
This is a frequency characteristic comparison diagram between frequency characteristic A of a speaker built into a speaker unit and frequency characteristic B of a conventional cone-shaped diaphragm speaker with a uniform heating temperature of 120°C, and it is clear from this comparison diagram. Example 1
It is found that the high-frequency characteristics of the conventional type A are suppressed compared to the conventional type B.

[Effects of the Invention] According to the speaker diaphragm of the present invention, in a diaphragm manufactured by thermoforming a resin-impregnated woven fabric, the shape and thickness of the diaphragm can be changed without changing the shape or thickness of the speaker. The frequency characteristics can be controlled, and if this is combined with means for changing the shape and thickness of the diaphragm, control becomes easier.

In this way, there is an effect that the frequency characteristics can be easily controlled, which was not possible conventionally with the same woven fabric.

[Brief explanation of drawings]

The drawings show an example of a speaker diaphragm according to the present invention,
Fig. 1 is a plan view of a cone-shaped diaphragm, Fig. 2 is a side view of the same as above, Figs. 3 and 4 are plan views showing other examples of formation patterns of low elasticity parts, and Fig. 5 is a dome-shaped diaphragm. An example of a plate is shown, in which (A) is a plan view and (B) is a side view. FIG. 6 is a frequency characteristic comparison diagram comparing the frequency characteristics of a speaker using the diaphragm of FIG. 1 with the frequency characteristics of a speaker using a conventional diaphragm. Figure 1 Figure 3 Figure 5 1: Entire diaphragm, 2: Low elastic part

Claims (1)

[Claims] 1. A woven fabric made of high-strength polyethylene fibers (density 0.98 or less, elastic modulus 10800 Kg/mm^2) or a woven fabric made of this high-density polyethylene fiber and other organic or inorganic fibers. In a speaker diaphragm manufactured by impregnating a thermosetting resin with a resin-impregnated woven fabric and then thermo-pressing the resin-impregnated woven fabric after drying, a part of the resin-impregnated woven fabric is heated to a temperature in the range of 120°C to 150°C during the thermo-pressing molding. A diaphragm for a speaker, characterized in that a low elasticity portion is formed in a part of the diaphragm by thermoforming inside the diaphragm. 2. The speaker diaphragm according to claim 1, wherein the elastic modulus of the high-strength polyethylene fibers in the low-elasticity portion is 1/2 or less of the elastic modulus of the high-strength polyethylene fibers in other portions. 3. The diaphragm for a speaker according to claim 1, wherein the low elasticity portion is formed in a frequency dividing manner or in a ring shape.